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| GUID,Title,Abstract,status,"file url","Download count",URL,"Preprint DOI","Publisher DOI","Date created","Date modified" | |
| mkzp5,"A stochastic multiscale peridynamic model for corrosion-induced fracture","Concrete fracture caused by corrosion of the reinforcing bars plays a key role in accelerating rebar corrosion and causing subsequent structure failure. To better predict this process, we introduce a three-phase stochastic peridynamic model, with the simplest constitutive relation (linear elastic with brittle failure), that avoids the need for explicit concrete microstructure geometry representations. The model links information from the composition at the microscale (phase volume fractions) to the macroscale fracture behavior, while costing the same as a fully homogenized model. We show that a similar peridynamic homogenized model fails in capturing the correct fracture modes/patterns in these problems where the microstructure controls failure behavior. The multiscale model is used to study fracture in reinforced concrete caused by the expansion of corrosion products in samples with a single or multiple rebars. The non-uniform expansion of corrosion products is enforced here as preset, incremental radial displacements. The peridynamic model finds fracture patterns and the order in which various cracks develop to be very similar to what is seen in experiments. The model’s robustness is tested under different microstructure realizations and discretization grid types.",1,https://api.osf.io/v2/files/5dd0daaa5b97bd000e596db9/,0,https://engrxiv.org/mkzp5/,10.31224/osf.io/mkzp5,,2019-11-17T13:10:34.581253,2019-11-17T13:11:02.800181 | |
| 2wsv6,"Nonlinear dynamics of an axially moving beam with fractional viscoelastic damping","Nonlinear dynamics of an axially moving viscoelastic beam subjected to transverse harmonic excitation is studied. The governing equation of motion of this system is discretized by employing Galerkin’s technique which yields a single-degree-of-freedom Duffing system having nonlinear fractional derivative. The viscoelastic properties of the material are described by the fractional Kelvin–Voigt model based on the Caputo definition. The primary resonance is analytically investigated by the averaging method. With the aid of response curves, a parametric study is conducted to display the influences of the fractional order and the viscosity coefficient on steady-state responses. The validations of this study are given through comparisons between the analytical solutions and numerical ones, where the stability of the solutions is determined by the Routh-Hurwitz criterion. It is found that suppression of undesirable responses can be achieved via changing the viscosity of the system.",1,https://api.osf.io/v2/files/5dcfafab9a4252001214edb1/,2,https://engrxiv.org/2wsv6/,10.31224/osf.io/2wsv6,,2019-11-16T14:16:33.782416,2019-11-16T14:16:41.619631 | |
| acxsp,"Failure mode and effects analysis of LFP battery module","The analysis of the charge/discharge curve helps judge the quality of cells and figure out some strange behaviors of the battery module. Especially, many unusual behaviors won’t exhibit on the appearance. It’s important to establish the charge/discharge profile database for effective manufacturing and troubleshooting. In this talk, the basic charge/discharge method of Li-ion battery, simple equivalent circuit model of battery, general charge/discharge curve of LFP battery will be introduced. Then a case-by-case failure mode and effects analysis will be presented. Up to ten cases are discussed in the slides. | |
| Dr. Hsien-Ching Chung was invited by Dr. Jim Lee (the chairman of Taiwan Battery Association) to give a talk about ""Failure mode and effects analysis of LFP battery module"" in the conference, ""2018 Taiwan-Japan exchange conference on battery materials and battery manufacturing technologies."" The conference was held in Center for Space and Remote Sensing Research, National Central University, Taoyuan, Taiwan on Dec. 18, 2018. There were about 20 keynote speakers and 150 participants. It's a good opportunity to realize new technologies in the battery industry and the future of the energy industry.",1,https://api.osf.io/v2/files/5dcd87e8360e17000da1d595/,7,https://engrxiv.org/acxsp/,10.31224/osf.io/acxsp,,2019-11-14T17:36:22.041506,2019-11-14T17:45:40.085459 | |
| k2dt5,"A Method for Superelastic Constitutive Properties Calibration Using Full-field Surface Strain Data","Superelastic Nitinol is a widely used material to manufacture implantable medical devices. Simulations are extensively used in the design, optimization, and durability assessment of Nitinol implants. The constitutive response of superelastic materials is non-linear, anisotropic, and asymmetric in tension vs. compression. The existing methods to determine the superelastic material properties used in finite element simulations typically do not account for some of these complexities. The goal of this work is to introduce a method to determine the superelastic material constitutive properties using full-field surface strain measurements. We propose using digital image correlation to obtain surface strain fields during tensile testing of specially designed diamond specimens. The material properties are determined by minimizing a difference metric defined in terms of the local strain difference and the global load difference between the experiment and trial simulations. We also propose a metric in terms of the local strain difference between experimental measurement and simulation prediction to report the credibility of the material properties fitted using this method. The philosophy behind this method and the proposed metric to quantify the accuracy of material property fitting reflects the growing consensus in the implantable device community that the simulation results must be accompanied by a quantification of their credibility.",1,https://api.osf.io/v2/files/5dcc69851640ea000d960a39/,21,https://engrxiv.org/k2dt5/,10.31224/osf.io/k2dt5,,2019-11-13T22:08:38.694033,2019-11-13T22:09:11.436534 | |
| 7hqnt,"Comparative analysis of electro-mechanical properties of enameled winding wires filled with a silica nanofiller","This study deals with the use of a nanofiller, AEROSIL® R 972, a form of fumed silica with an average diameter of around 16nm and specific surface area of 110m2/g. This nanofiller is used in combination with the Polyamide Imide Wire Enamel to create a nanocomposite AI 32 S suspension. The investigation is a comparative study, using different proportions of nanofiller and a reference sample containing no filler, to determine any potential changes in electrical and mechanical properties of the wire enamel. Experimental results showed improvements in surface finish of the coat, viscosity, abrasion resistance and breakdown voltage.",1,https://api.osf.io/v2/files/5dcc2ea5b51f84000ceb38eb/,7,https://engrxiv.org/7hqnt/,10.31224/osf.io/7hqnt,,2019-11-13T19:28:45.970934,2019-11-13T19:29:04.488252 | |
| w8u9r,"Amplitude Division Multiple Access Using Uniqueness of Prime Factorization","A new method of amplitude division multiplexing (ADMA) is proposed, where a single channel can be used to transmit multiple digital signals simultaneously using the concept of prime number factorization. This method contrasts with the currently used methods such as frequency-division multiple access (FDMA), in which | |
| the total bandwidth available in a channel is divided into a series of non-overlapping frequency bands, each of | |
| which is used to carry a separate signal. Comparison of the proposed method with a popular PAM technique-2B1Q method is made. Distinct advantages of the proposed method and a few applications are | |
| presented.",1,https://api.osf.io/v2/files/5dca75e4a1cd9e000b7402b7/,14,https://engrxiv.org/w8u9r/,10.31224/osf.io/w8u9r,,2019-11-12T14:24:52.774948,2019-11-12T14:25:03.546607 | |
| duz8g,"Artificial General Intelligence: A New Perspective, with Application to Scientific Discovery","The dream of building machines that have human-level intelligence has inspired scientists for decades. Remarkable advances have been made recently; however, we are still far from achieving this goal. In this paper, I propose a new perspective on how these machines might be built focusing on the scientific discovery process which represents one of our highest abilities that requires a high level of reasoning and remarkable problem-solving ability. By trying to replicate the procedures followed by many scientists, the basic idea of the proposed approach is to apply a set of principles on concept maps to solve problems and discover new knowledge. These principles are extracted from different historical examples of scientific discoveries. Building machines that fully incorporate these principles in an automated way might open the doors for many advancements.",1,https://api.osf.io/v2/files/5dc89efd8f0e5e000cd16325/,21,https://engrxiv.org/duz8g/,10.31224/osf.io/duz8g,,2019-11-11T13:46:29.544163,2019-11-11T13:46:44.592721 | |
| 4qneu,"A Non-Iterative Field Based Vector Quantization Algorithm","This article describes a new and innovative algorithm for quantizing vectors in a two dimensional space in a non-iterative way. Additionally, this technique produces an optimal number of quantized vectors, and hence, the knowledge of the number of quantized vectors is not needed beforehand.",1,https://api.osf.io/v2/files/5dc7f73e7f37e3000dcbe9f5/,18,https://engrxiv.org/4qneu/,10.31224/osf.io/4qneu,,2019-11-10T18:16:00.948214,2019-11-10T18:16:25.173776 | |
| r23dw,"Time Frequency analysis of data from the Vela Pulsar","In this article, the procedure to conduct the time-frequency analysis of data recieved from distant pulsars, such as the Vela pulsar is explored. Problems that are encountered and solutions to these problems are also mentioned.",1,https://api.osf.io/v2/files/5dc70f828f0e5e000bd05de6/,13,https://engrxiv.org/r23dw/,10.31224/osf.io/r23dw,,2019-11-09T22:58:48.569544,2019-11-09T22:59:01.932663 | |
| 4j83z,"An experimental and computational investigation of the effects of volumetric boundary conditions on the compressive mechanics of passive skeletal muscle","Computational modeling, such as finite element analysis, is employed in a range of biomechanics specialties, including impact biomechanics and surgical planning. These models rely on accurate material properties for skeletal muscle, which comprises roughly 40% of the human body. Due to surrounding tissues, compressed skeletal muscle in vivo likely experiences a semi-confined state. Nearly all previous studies investigating passively compressed muscle at the tissue level have focused on muscle in unconfined compression. The goals of this study were to (1) examine the stiffness and time-dependent material properties of skeletal muscle subjected to both confined and unconfined compression (2) develop a model that captures passive muscle mechanics under both conditions and (3) determine the extent to which different assumptions of volumetric behavior affect model results. Muscle in confined compression exhibited stiffer behavior, agreeing with previous assumptions of near-incompressibility. Stress relaxation was found to be faster under unconfined compression, suggesting there may be different mechanisms that support load these two conditions. Finite element calibration was achieved through nonlinear optimization (normalized root mean square error <6%) and model validation was strong (normalized root mean square error <17%). Comparisons to commonly employed assumptions of bulk behavior showed that a simple one parameter approach does not accurately simulate confined compression. We thus recommend the use of a properly calibrated, nonlinear bulk constitutive model for modeling of skeletal muscle in vivo. Future work to determine mechanisms of passive muscle stiffness would enhance the efforts presented here.",1,https://api.osf.io/v2/files/5dc70e6c7f37e3000dcb7208/,38,https://engrxiv.org/4j83z/,10.31224/osf.io/4j83z,10.1016/j.jmbbm.2019.103526,2019-11-09T22:54:29.303575,2019-11-09T22:54:44.960404 | |
| g7v2a,"LAY-UP OPTIMALITY CONDITIONS FOR BUCKLING LEVEL MAXIMIZATION OF VAT (STEERED FIBER) COMPOSITE PLATES","IIn the present paper the flat composite plates in buckling are studied. The plates have a symmetric lay-up and loaded along their contour by the in-plane forces. The consideration employs the von Karman approach. The lay-up optimality conditions for a single-mode (lowest) buckling eigenvalue are derived using the proper variational principles and the variation calculus. Both the bending terms and the terms following from the redistribution of the 2D stresses over the plate are taken into account. The optimality conditions contain two items (corresponding to the bending and to the 2D infinitesimal plane strains). The comparative analysis of the items is performed. The physical meaning of the optimality conditions is demonstrated and explained. An illustration to the derived conditions is presented and analyzed. It is shown that for the optimal lay-up not all lamination parameters are independent on each other (one of them is a linearly dependent one). The analysis leads to a conclusion that the optimization w.r.t. the lamination parameters only is not sufficient for obtaining an optimal plate lay-up.",1,https://api.osf.io/v2/files/5dc6f657ee9bb9000e4c0625/,19,https://engrxiv.org/g7v2a/,10.31224/osf.io/g7v2a,,2019-11-09T22:57:09.694408,2019-11-13T15:43:35.269427 | |
| m3ycp,"Dimensional Analysis: Overview and applications to problems of Soil-Structure Interaction","Dimensional Analysis is a long-established tool widely used in many branches of engineering and science. However, applications in geotechnical engineering, and in particular soil-structure interaction (SSI), have barely been explored, in spite of the method's potential to clarify parameter influence and shed light on the range of response regimes. The purpose of this text is twofold: (a) it intends to provide a brief introduction to Dimensional Analysis specifically tailored to geotechnical engineers by carefully choosing illustrative examples, (b) it uses Dimensional Analysis to study the parameter space in soil-building interaction problems, emphasizing modeling choices and using a finite-element model to demonstrate the concept of physical similarity. The suitability of using certain dimensionless parameters over others is discussed based on and their magnitude and sensitivity analysis.",1,https://api.osf.io/v2/files/5dc669b4a1cd9e000b719b2d/,45,https://engrxiv.org/m3ycp/,10.31224/osf.io/m3ycp,,2019-11-09T13:29:30.843997,2019-11-09T13:29:44.542446 | |
| p6sya,"Threshold Voltage variation with respect to Gate geometry in Nano-scale MOSFETS","The tremendous progress in Metal Oxide | |
| Semiconductor (MOS) technology has been a direct consequence | |
| of device scaling for past several decades. But as we have | |
| entered the nanometer era many problems related to leakage | |
| currents and other issues related to variability impacting the | |
| yield are of concern. Herein we have investigated how the change | |
| in the Fin Architecture and Gate Length of the MOS device | |
| impacts the Threshold Voltage.",1,https://api.osf.io/v2/files/5dc4f48c7f37e3000eca4ab8/,18,https://engrxiv.org/p6sya/,10.31224/osf.io/p6sya,,2019-11-08T12:31:22.952806,2019-11-08T12:31:44.763826 | |
| bg4m7,"Bitstream Photon Counting Chirped AM Lidar with a Digital Logic Local Oscillator","This paper introduces a new concept for the local oscillator (LO) for the Photon Counting Chirped Amplitude Modulation Lidar (PC-CAML). Rather than using a radio-frequency (RF) analog LO applied electronically either in post-detection mixing or via opto-electronic mixing (OEM) at the detector, or applied via pre-detection mixing using an optical intensity modulator as in previous systems, the new method mixes the single-bit binary counts from the photon counting detector with a single-bit binary LO using an AND binary digital logic gate. This type of LO is called the Digital Logic Local Oscillator (DLLO), and the resulting PC-CAML system is a type of bitstream lidar called bitstream PC-CAML (patent pending). | |
| The key advantage of the DLLO in the bitstream PC-CAML is that it replaces bulky, power-hungry, and expensive wideband RF analog electronics with single-bit digital logic components that can be implemented in inexpensive silicon complementary metal-oxide-semiconductor (CMOS) read-out integrated circuits (ROICs) to make the bitstream PC-CAML with a DLLO more suitable for compact lidar-on-a-chip systems and lidar array receivers than previous PCCAML systems. | |
| This paper introduces the DLLO for bitstream PC-CAML concept, presents the initial signal-to-noise-ratio (SNR) theory with comparisons to Monte Carlo simulation results, and makes suggestions for future work on this concept.",1,https://api.osf.io/v2/files/5dc333405bd3dd000abc2bbb/,37,https://engrxiv.org/bg4m7/,10.31224/osf.io/bg4m7,,2019-11-06T21:30:34.590668,2019-11-13T17:26:33.586715 | |
| rqfsp,"On the fundamental resonant mode of inhomogeneous soil deposits","The problem of estimating seismic ground deformation bears paramount importance to engineers designing and maintaining infrastructure in earthquake-prone areas. Notwithstanding its vital importance, the quantification of this deformation is still an open research area that concerns from engineers to seismologists and geophysicist. Particularly, the problem of finding the displacement field in a soft shallow layer overlying rigid bedrock induced by simple SH wave excitation has been favored by engineers due to its simplicity combined with inherent relevance for practical scenarios. This document furnishes accurate estimates for both the fundamental frequency and the amplitude of the first resonant mode which does not require considering a continuous inhomogeneity distribution. These are attained through application of a new physical argument based on resonance of single-degree-of-freedom systems.",1,https://api.osf.io/v2/files/5dc3293075b4f1000d392506/,52,https://engrxiv.org/rqfsp/,10.31224/osf.io/rqfsp,,2019-11-06T21:13:51.101360,2019-11-15T04:28:45.348168 | |
| uv8m7,"Extracting elastic constitutive parameters using the VFM within peridynamics","This paper implements the Virtual Fields Method within the ordinary state based peridynamic framework to identify material properties. The key equations derived in this approach are based on the principle of virtual works written under the ordinary state based peridynamic formalism for two-dimensional isotropic linear elasticity. In-house codes including a minimization process have also been developed to implement the method. A three-point bending test and two independent virtual fields arbitrarily chosen are used as a case study throughout the paper. The numerical validation of the virtual fields method has been performed on the case study by simulating the displacement field by finite element analysis. This field has been used to extract the elastic material properties and compared them to those used as input in the finite element model, showing the robustness of the approach. Noise analysis and the effect of the missing displacement fields on the specimen’s edges to simulate digital image correlation limitations have also been studied in the numerical part. This work focuses on pre-damage properties to demonstrate the feasibility of the method and provides a new tool for using full-field measurements within peridynamics with a reduced calculation time as there is no need to compute the displacement field. Future works will deal with damage properties which is the main strength of peridynamics.",1,https://api.osf.io/v2/files/5dc0e5eb96af97000d183462/,76,https://engrxiv.org/uv8m7/,10.31224/osf.io/uv8m7,,2019-11-05T19:35:00.089207,2019-11-05T20:47:21.475876 | |
| ga4vs,"Enabling materials for subwavelength-size low-loss surface modes in the Terahertz spectral range","Terahertz spectral range (frequencies of 0.1-1 THz) has recently emerged as the next frontier for non-destructive imaging, industrial sensing and ultra-fast wireless communications. Here, we review several classes of materials such as simple metals, semiconductors, high-k dielectrics, polar materials, zero gap materials, as well as structured materials that can support strongly localized electromagnetic modes at material interfaces in the Terahertz spectral range. We present the basic theory of surface waves, detail the requirement of strong modal confinement and low loss for the surface waves propagating at material interfaces and discuss challenges for excitation of such modes at Terahertz frequencies. A large number of examples related to naturally occurring and artificial materials is then presented. A variety of practical applications is envisioned for surface waves at Terahertz frequencies including non-destructive super-resolution imaging and quality control, high sensitivity sensors capable of operation with small volumes of analytes that are opaque in the visible and near-infrared, as well as design of compact optical circuit for the upcoming ultra-high bitrate THz communication devices.",1,https://api.osf.io/v2/files/5dc0c8c6e18a3c000dc5261f/,60,https://engrxiv.org/ga4vs/,10.31224/osf.io/ga4vs,,2019-11-05T01:36:22.643738,2019-11-05T01:38:01.734112 | |
| sfkwv,"Finite Element Model of Composite Connections Strengthened with CFRP Laminates","Carbon Fiber Reinforced Polymer (CFRP) materials are being widely used for structural applications. Despite the relatively high cost of the CFRP materials, their high strength-to-weight ratio and corrosion resistance as well as easy handling and installation have made them widely popular for different civil engineering applications where increased strength and/or ductility is important. This thesis investigates the moment-rotational response of an endplate composite connection including strengthening of the slab by using different sizes and thickness of CFRP sheets in hogging moment regions and different reinforcement bar ratios by using finite element simulations. A three dimensional non-linear model is developed in ANSYS to study the feasibility of decreasing the reinforcing bars in the presence of the CFRP laminate in hogging moment regions of the slab. The verification of the analysis is carried out to calibrate the un-strengthened model by available experimental results obtained from a series of composite connection tests as reported by other researchers. The moment resistance for the partial depth endplate composite connection obtained by ANSYS 12.1 software is found to be very close to the corresponding laboratory test value. From the results it can be observed that applying CFRP sheets to the tension face of composite slab can reduce the amount of steel reinforcement bars required for flexural strength of composite connections.",1,https://api.osf.io/v2/files/5dbf8a70f3bb87000d90918f/,66,https://engrxiv.org/sfkwv/,10.31224/osf.io/sfkwv,,2019-11-04T14:30:20.359329,2019-11-04T14:30:42.942422 | |
| 8ht2m,"On The Quantum Computability Of The 3 Satisfiability Solution Space","We present a treatise on a new quantum theoretic algorithm for solving the 3 Satisfiability problem. The presented algorithm is not a standard quantum algorithm in the sense that it is intended solely for true “physical” quantum systems (if it at all can be realized on these systems). Instead, we posit that the 3 Satisfiability problem has an intrinsic complex quantum form that can be programmed in order to build a model of the solution space for satisfiable instances or show that such a model cannot be constructed. This yields surprising results on the ability for classical systems to abstractly simulate general quantum systems. We also present other relevant structures, mathematical and physical, that bear close analogies with the methods and structures presented.",1,https://api.osf.io/v2/files/5dbe37a5bc32f4000f174679/,45,https://engrxiv.org/8ht2m/,10.31224/osf.io/8ht2m,,2019-11-03T17:01:20.939277,2019-11-03T17:01:41.941443 | |
| zrt52,"IMPROVING THERMO-OPTIC PROPERTIES OF SMART WINDOWS VIA COUPLING TO RADIATIVE COOLERS","In this work we first solve the radiative heat transfer problem in one dimension to perform a comparative analysis of the time averaged performance of the partially transparent radiative windows and radiative coolers. In doing so we clearly distinguish the design goals for the partially transparent windows and radiative coolers and provide optimal choice for the material parameters to realize these goals. Thus, radiative coolers are normally non-transparent in the visible, and the main goal is to design a cooler with the temperature of its dark side as low as possible relative to that of the atmosphere. For the radiative windows, however, their surfaces are necessarily partially transparent in the visible. In the cooling mode the main question is rather about the maximal visible light transmission through the window at which the temperature on the window somber side does not exceed that of the atmosphere. We then demonstrate that transmission of the visible light through smart windows can be significantly increased (by as much as a factor of 2) without additional heating of the windows via coupling of the windows to the radiative coolers using transparent cooling liquid that flows inside of the window and radiative cooler structures. We demonstrate that efficient heat exchange between radiative coolers and smart windows can be realized using small coolant velocities (sub 1mm/s for ~1m-large windows) or even using a purely passive gravitationally driven coolant flows between a hot smart window and a cold radiative cooler mounted on top of the window with only a minimal temperature differential (sub-1K) between the two. We believe that our simple models complimented with an in-depth comparative analysis of the standalone and coupled smart windows and radiative coolers can be of interest to a broad scientific community pursuing research in these disciplines.",1,https://api.osf.io/v2/files/5dbe1bfdcfc96c000ec8288b/,75,https://engrxiv.org/zrt52/,10.31224/osf.io/zrt52,,2019-11-03T16:57:43.766665,2019-11-03T16:58:01.966862 | |
| fnm6u,"Novel method for handling Ethereum attack","Block-chain world is very dynamic and there is need for strong governance and underlying technology architecture to be robust to face challenges. This paper considers Ethereum, a leading block chain. We deep dive into the nature of this block chain, wherein for software upgrades forks are performed. They types of forks and impact is discussed. A specific Ethereum hack led to a hard fork and focus is provided on understanding the hack and overcoming it from a novel approach. The current model has been unable to handle multiple Ethereum attacks. Thus the current approach is compared against a novel approach providing a security and scaling solution. Here the architecture draws upon combining block-chain layers into operating system level. The approach can have tremendous benefits to block chain world and improve the way decentralized application teams perform. The benefits of the novel architecture is discussed. The approach helps safe guard block chain projects, making them safer and chain agnostic.",1,https://api.osf.io/v2/files/5dbe008ccfc96c000ec815e8/,19,https://engrxiv.org/fnm6u/,10.31224/osf.io/fnm6u,,2019-11-02T22:45:47.920941,2019-11-02T22:46:02.766316 | |
| 8sxcd,"An artificial neural network model for predicting characteristic input parameters for physics based modelling of drying process","Drying is crucial in the quality preservation of food materials. Physics-based models are effective tools to optimally control the drying process. However, these models require accurate thermo-physical properties; unavailability or uncertainty in the values of these properties increases the possibility of error. Property estimation methods are not standardized, and usually involve the use of many instruments and are time-consuming. In this work, we have developed an experimentally validated deep learning-based artificial neural network model that estimates sensitive input parameters of food materials using temperature and moisture data from a set of simple experiments. This model predicts input parameters with error less than 1%. Further, using input parameters, physics-based model predicts temperature and moisture to within 5% accuracy of experiments. The proposed work when interfaced with food machinery could play a significant role in process optimization in food processing industries.",1,https://api.osf.io/v2/files/5dbd998bf3bb87000c8b1540/,27,https://engrxiv.org/8sxcd/,10.31224/osf.io/8sxcd,,2019-11-02T18:25:17.142118,2019-11-02T18:25:42.643861 | |
| j5zb7,"Mechanisms and Occurrence of Detonations in Vapor Cloud Explosions","Not all accidental releases of flammable gases and vapors create explosions. Most releases do not find an ignition source, and of those that do ignite, most of them result in deflagrations that generate low or moderate overpressures. Under some circumstances, however, it is possible for deflagration-to-detonation transition (DDT) to occur, and this can be followed by a propagating detonation that quickly consumes the remaining detonable cloud. In a detonable cloud, a detonation creates the worst accident that can happen. Because detonation overpressures are much higher than those in a deflagration and continue through the entire detonable cloud, the damage from a DDT event is more severe. | |
| This paper first provides a brief summary of our knowledge to date of the fundamental mechanisms of flame acceleration and DDT. This information is then contrasted to and combined with evidence of detonations (detonation markers) obtained from large-scale tests and actual large vapor cloud explosions (VCEs), including events at Buncefield (UK), Jaipur (India), CAPECO (Puerto Rico), and Port Hudson (US). The major conclusion from this review is that detonations did occur in prior VCEs in at least part of the VCE accidents. Finally, actions are suggested that could be taken to minimize detonation hazards.",1,https://api.osf.io/v2/files/5dbcbf58cfc96c000cc1a05f/,74,https://engrxiv.org/j5zb7/,10.31224/osf.io/j5zb7,,2019-11-02T18:23:26.524601,2019-11-02T18:23:42.630401 | |
| cmazh,"Mechanisms and Occurrence of Detonations in Vapor Cloud Explosions: Supplemental Material","The material in this paper comprise a compendium of more detailed information and analyses of the 14 large-scale explosions described the paper Mechanisms and Occurrence of Detonations in Vapor Cloud Explosions by Oran, Chamberlain, and Pekalski [Progress in Energy and Combustion Science, doi.org/10.1016/j.pecs.2019.100804). Each section begins with a general description of the incident and then, where possible, more analysis (based on the work of GC) and useful information about the incident. The events all have certain physical similarities, but vary greatly in terms of the level of information available for analysis. Taken together, however, they present a powerful picture of what a detonation can do as well as indications of what might be done in the future to avoid such an incident.",1,https://api.osf.io/v2/files/5dbca937bc32f4000f15f295/,49,https://engrxiv.org/cmazh/,10.31224/osf.io/cmazh,,2019-11-01T22:35:06.248472,2019-11-02T01:03:15.076085 | |
| 4uqb2,"A simplified model for predicting shrinkage during low temperature air drying of porous food materials","Food materials shrink when they are air-dried. However, owing largely to the complexity of modelling, most drying models so far have neglected this shrinkage, leading to inaccurate predictions. The empirical nature, inability to yield data on location-specific deformations and computational cost of detailed poro-mechanistic analyses and complex deformation modelling approaches make them unattractive for models that could be used in real-time process control algorithms. In this work, we develop a simplified transport model to predict spatial and temporal shrinkage during low temperature air drying process, and validate the model with experiments. In such drying, volumetric change is dominated by moisture loss; therefore the role of gas induced porosity is neglected. This model predicts shrinkage, temperature and moisture content at each spatial location at time intervals during the drying process. The model agrees well with experiments conducted by us (reported in this paper) as well as with those conducted by others (taken from the literature) on food samples. We expect that this generalized model will find wide applications in the food processing industry.",1,https://api.osf.io/v2/files/5dbbb71ecfc96c000bc15556/,12,https://engrxiv.org/4uqb2/,10.31224/osf.io/4uqb2,,2019-11-01T17:02:12.916163,2019-11-01T17:02:42.655160 | |
| k8nec,"Finite Element Analysis of Precast Concrete Connections under Incremental load","Beam-to-column connections affect the rigidity and strength of the overall precast concrete structures. Even though many experimental researches have been carried out on beam-to-column connections, the behavior and failure mode of the connection in precast concrete is often difficult to assess through experimental program. The finite element analysis, on the other hand, can be an option to properly evaluate the condition of the connections. Nevertheless, the finite element analysis on the beam-to-column connections is quite limited. Thus, there is a need to study and explore the behavior of the connection system based on the finite element data. In this research, the finite element analysis was performed to study the performance of different types of beam-to-column connections in precast concrete frames. A total of four specimens were modeled and analyzed to study the connection behavior involving load-displacement relationship under static incremental load. Different connection details were considered and the behavior of various beam-to-column connections were investigated.",1,https://api.osf.io/v2/files/5dbb929bf3bb87000c898c42/,26,https://engrxiv.org/k8nec/,10.31224/osf.io/k8nec,,2019-11-01T17:00:45.720898,2019-11-01T18:26:50.712908 | |
| gdu7v,"Regression Test Suite Study using Classic Statistical Methods and Machine Learning","This work is inter disciplinary in nature. This work tries to apply latest discoveries in Artificial Intelligence to classic testing methodologies. Machine Learning which is the field of Artificial Intelligence is explored in this work. The | |
| work demonstrates that provided the test team maintains the required data, Machine Learning Algorithms can aid in deciphering patterns from the test data. Patterns of interest are the relation between testers experience in the project and bugs uncovered, relations between the testers experience and the efficiency of test case with respect to code coverage and test execution time. Relation between testers experience and efficiency of test case with respect to code coverage and execution | |
| time, relation between testers experience and bugs uncovered are explored using classic statistical techniques and clustering Machine Learning Algorithms. This clustering can be of immense help in test selection, prioritization, pruning and Regression test execution time reduction.",1,https://api.osf.io/v2/files/5dbb6b04f3bb87000b87da65/,30,https://engrxiv.org/gdu7v/,10.31224/osf.io/gdu7v,,2019-11-01T17:03:19.324307,2019-11-01T17:03:47.169149 | |
| qwcav,"Thin X ray Lens Design And Simulation","A proposal of thin sandwich mirror array lens for X-ray telescope Wolter type lens is discussed. We discussed a process of design, fabrication of this thin X-ray lens and conducted a simulation and provided a measurement method for lens focal quality. The lens consists of two connected layers of arrays of rings of mirrors, one is of parabolic mirror and another is of hyperbolic mirrors. In each layer, the mirror coating is deposited on a substrate and next substrate in turn is deposited on this mirror film, leaving no air gap. Repeat this process to form an array of mirrors. Hence form a solid thin disc sandwich mirror lens and each ring of mirror can be curved precisely by polishing process. X ray travels into the transparent substrate and grazes on the surface of the mirror coating facing the substrate. Using geometrical optics ray tracing, we conducted simulation with two artificial distance stars as the source objects, a virtual lens of mirror array and a disc placed at the focal plane as the receiver CCD. Simulation shows that the star located off optical axis forms corn shape patterns by its ray crossing pointa on CCD disc. Those patterns may provide the baseline pattern for further image deconvolution or aberration reducing algorithm. The corn pattern is related to the dimensional structure of the lens and the space location of the star; hence, it contains some information about space location of the star. A simulation of ray tracing video is made as well. The thin sandwich lens we discussed in this paper may provide a way to build a large aperture telescope X ray lens",1,https://api.osf.io/v2/files/5db99551af84c3000be677da/,29,https://engrxiv.org/qwcav/,10.31224/osf.io/qwcav,,2019-10-30T17:40:11.405359,2019-10-30T17:40:45.890599 | |
| dxt6u,"*Locating an iBeacon with GPS, using amateur radio VHF and the AMSAT satellite PSAT, NO-84, cubesat, using AX.25.*","Abstract: | |
| Resupply by airdropping or drone-shipping is a new resupply strategy in backpacking. In preparation for reconnaissance in long distance backpacking and SAR activities in remote areas, with little or no development, we consider the use of amateur radio with GPS beacons for resupply tracking | |
| and geo-tagging. | |
| While 6G communications using GPS satellites are available for mountaineering beacons, we use a dual strategy with an additional amateur radio based AX.25 packet radio using the PSAT based cubesat for publishing location information. | |
| Additionally, two cargo iTag locating satellites, bot cubesats are also used for iTag location and the automatic publication of tag locations on geocaching.com. The satellites are AENEAS and PTecSAT. | |
| A logistics exercise is introduced, proposed to be conducted at Uncas Scientific Area, near Big Lake, MN, with an operations logistik for the spanning of drop locations and radio fox hunt, using a reconnaissance track, mobile cache device. | |
| Keywords: iTag, iBeacon, AMSAT, cubesat, AENEAS, PTecSAT, 6G, AX.25, resupply, mountaineering and backpacking, SAR. | |
| What: | |
| The AMSAT AENEAS(“Technical Details for Satellite AENEAS” n.d.), PTecSAT(“IARU Sat Coordinator” n.d.) satellite is used for resupply iBeacon tracking, with a payload of water sachets and soylent coffee packs, for mountaineering resupply logistics. Radio Fox Hunting combined with alpining is defined as a newer, ultralight backpacking technique. | |
| How: | |
| iBeacons, defining 100msec bursts at 2.425GHz are designed with the minimum wattage needed for detection on the field by the AENEAS satellite. 100 such packages containing 1-liter pouches of potable water and three meals of soylent of 87 grams each. This proof of concept study is to be conducted at Uncas Dunes Scientific and Natural Area (SNA), with an area of 658.3 acres , we have a density of airdropping of 6.58 acres per package, leading to an average distance of 26628.32 square meters, by pi/4 d^2, d is 184 meters in circle close packing model. | |
| We determine an optimal trajectory for the radio fox hunt over a published geotag distribution of 100 resupply caches. | |
| Why: | |
| Resupply strategies, form an important role in long distance mountaineering and backpacking missions, for wilderness areas with little or no little development, for example the pacific crest trail, in the united states, a strong resupply strategy along with an armada of reconnaissance track mobile caches are needed for effective mountaineering and/or search and rescue operations, with a resilience plan for extreme weather operations. | |
| The use of 6G like simulated communication is possible by using better encryption and packet compression over a slower AX.25 network, with the use of A.I based technologies like image cartoonization and feature representation and speech to text conversion for lower bandwidth requirements. | |
| So What: | |
| The use of reconnaissance tracks, along with airdropped resupply, will improve the efficiency and quality of mountaineering and provide vital air support for search and rescue operations. Resupply beacons also provide supplies for hikers or backpackers lost in the wilderness and also provide emergency communication hotspots as the beacons are still active to transreceiver emergency messages.",1,https://api.osf.io/v2/files/5db8839ef3bb87000d88aa46/,19,https://engrxiv.org/dxt6u/,10.31224/osf.io/dxt6u,,2019-10-30T17:38:41.385040,2019-10-30T17:39:22.676805 | |
| 4myqe,"High salinity enhances adsorption of 17α-ethinyl estradiol by polyethersulfone membrane: Isotherm modelling and molecular simulation","The increasing occurrence of steroidal hormone micropollutant in the aquatic environment and their associated consequences have caused serious environmental concerns globally. Adsorptive removal of hormonal pollutants using polymeric membranes have been suggested but information on their performance in various environmental conditions is lacking. In this study, we examined the effect of salinity on the performance of polyethersulfone (PES) membrane to remove synthetic hormone 17α-ethinyl estradiol (EE2) from water. Our results show that an increase of salinity from 0 to 3% results in an improved retention of EE2 onto PES membrane from 79.3% to 98.7%. The experimental results fit the Freundlich isotherm model better as compared to the Langmuir model. The Freundlich parameters n and Kf yielded the highest values at 3% salinity. Molecular simulation results suggest that a high salinity increases the binding energy between EE2 and PES membranes, promoting the PES-EE2 interaction through pi-pi interaction, hydrogen bonding and hydrophobic interaction. This study provides valuable information for improving treatment plant design to allow better removal of EE2 and other low-polar organic contaminants from water via membrane-based sorption-elution method, and may also serves as a proof-of-concept in adsorptive removal of organic contaminants in the pre-treatment process of seawater prior to desalination to reduce burden on reverse osmosis membranes.",1,https://api.osf.io/v2/files/5db82a7ccfc96c000dbf489b/,15,https://engrxiv.org/4myqe/,10.31224/osf.io/4myqe,,2019-10-29T15:45:45.350271,2019-10-29T15:46:07.316812 | |
| phfyd,"Effects of openings on the seismic behavior and performance level of concrete shear walls","In this study, the seismic behavior of the concrete shear wall considering the opening with different shapes and constant cross-section has been studied, and for this purpose, several shear walls are placed under the increasingly non-linear static analysis (Pushover). These case studies modeled in 3D Abaqus Software, and the results of the ductility coefficient, hardness, energy absorption, added resistance, the final shape, and the final resistance are compared to shear walls without opening.",1,https://api.osf.io/v2/files/5db66abfcfc96c000dbda0be/,11,https://engrxiv.org/phfyd/,10.31224/osf.io/phfyd,,2019-10-28T13:51:46.683073,2019-10-28T13:52:02.596050 | |
| qt27a,"Deep Learning Architectures for Automated Image Segmentation","Image segmentation is widely used in a variety of computer vision tasks, such as object localization and recognition, boundary detection, and medical imaging. This thesis proposes deep learning architectures to improve automatic object localization and boundary delineation for salient object segmentation in natural images and for 2D medical image segmentation. First, we propose and evaluate a novel dilated dense encoder-decoder architecture with a custom dilated spatial pyramid pooling block to accurately localize and delineate boundaries for salient object segmentation. The dilation offers better spatial understanding and the dense connectivity preserves features learned at shallower levels of the network for better localization. Tested on three publicly available datasets, our architecture outperforms the state-of-the-art for one and is very competitive on the other two. Second, we propose and evaluate a custom 2D dilated dense UNet architecture for accurate lesion localization and segmentation in medical images. This architecture can be utilized as a stand alone segmentation framework or used as a rich feature extracting backbone to aid other models in medical image segmentation. Our architecture outperforms all baseline models for accurate lesion localization and segmentation on a new dataset. We furthermore explore the main considerations that should be taken into account for 3D medical image segmentation, among them preprocessing techniques and specialized loss functions.",1,https://api.osf.io/v2/files/5db63e39cfc96c000bbd019b/,23,https://engrxiv.org/qt27a/,10.31224/osf.io/qt27a,,2019-10-28T13:49:51.465168,2019-10-30T02:44:35.601091 | |
| 7ce89,"Safety Analysis of Molten Salt Fast Reactor Fuel Composition using Moltres","The Molten Salt Fast Reactor (MSFR) has garnered much interest for its inherent safety and sustainbility features. The MSFR can adopt a closed thorium fuel cycle for sustainable operation through the breeding of 233 U from 232 Th. The fuel composition changes significantly over the course of its lifespan. In this study, we investigated the steady state and transient behavior of the MSFR using Moltres, a coupled neutronics/thermal-hydraulics code developed within the Multiphysics Object Oriented Simulation Environment (MOOSE) framework. Three different fuel compositions, start-up, early-life, and equilibrium, were examined for potentially dangerous core temperature excursions during a unprotected loss of heat sink (ULOHS) accident. The six-group and total neutron flux distributions showed good agreement with SERPENT and published MSFR results, while the temperature distribution and total power showed discrepancies which can be attributed to | |
| known sources of error. For the transient behavior under the ULOHS scenario, while the transition time towards the new steady state core temperature is also in good agreement with existing MSFR simulations by Fiorina et al., Moltres under- | |
| estimated the temperature rise by a factor of ten, due to the same sources of error affecting the steady state results. While an MSFR loaded with start-up fuel composition operates at a higher temperature than with the other two fuel compositions, all three cases were shown to be inherently safe due to the | |
| strong negative temperature feedback.",1,https://api.osf.io/v2/files/5db1f0ac365cb8000ad91e53/,80,https://engrxiv.org/7ce89/,10.31224/osf.io/7ce89,,2019-10-24T22:34:01.085875,2019-10-24T22:34:21.792723 | |
| nxv7f,"Action Planning and Situation Analysis of Repurposing Battery Recovery and Application in China (中國汰役電池回收利用的推動現況與分析)","Due to the vigorous promotion of commercialization and popularization of electric vehicles in China, the elimination of power batteries has gradually increased, causing environmental protection threats and waste of resources. Therefore, recycling and utilization of such batteries have been actively promoted in recent years. At present, the “Interim Measures for the Management of Recovery and Utilization of New Energy Vehicle Power Battery,” as well as related regulations and standards have been announced. The power battery traceability management platform has been established and promoted, so that the being counseled companies have cooperated to perform these policies. This article is mainly to explain the promotion system and current situation of recovery and reuse of repurposing batteries, including coding principles, traceability management system, manufacturing factory guidelines, dismantling process guidelines, residual energy measurement, etc., as well as analyze the promotion situation and policy in China. Currently, the industry and business of electric vehicles are still in the early stage of promotion. The main products include electric buses, electric motorcycles, and electric scooters. The relative policy about power battery recycling is under development. The policy, code, and standard in China and other countries can be used as references for promoting the recovery and reuse of repurposing batteries in the future in Taiwan. | |
| ----- | |
| 近年來中國大力推動電動車輛的商業化與普及化，導致汰役電池逐漸增加，造成環保威脅與資源浪費的問題。因此積極推動汰役電池的回收與利用。目前已經公布「新能源汽車動力蓄電池回收利用管理暫行辦法」，及相關法規與標準，並建立與推廣動力電池溯源管理平台，同時輔導產業界配合執行。本文主要在說明中國汰役電池回收利用的推動制度與現況，包括編碼規則、溯源管理、設廠規範、拆解規範、餘能量測等，並分析其政府單位與民間企業的推動情形，同時檢討我國相關發展狀況。我國目前電動車輛尚在初期推廣階段，目前主要為電動巴士與電動機車，相關回收政策仍在研擬中，因此中國與國際已有的法規、標準與做法，值得我們做為未來推動汰役電池回收再利用的參考。",1,https://api.osf.io/v2/files/5db1ec160db187000d3b350d/,49,https://engrxiv.org/nxv7f/,10.31224/osf.io/nxv7f,,2019-10-24T22:32:58.803316,2019-11-13T15:26:13.133268 | |
| d4n3s,"Brief Summary on Safety Standards for Repurposing Batteries (汰役電池安全標準的內容與說明)","As the increasing of electric vehicles, repurposing batteries begin to appear and will increase in quantity in the future. How to deal with repurposing batteries becomes an important problem that must be solved. Part of these retired power batteries still possesses about 80% of their initial capacity that can be used again, e.g., energy storage systems. However, repurposing batteries might cause safety problems. Underwriters Laboratories (UL) has published safety standards for batteries for use in stationary, vehicle auxiliary power and light electric rail applications (UL 1973). In order to promote the usage of repurposing batteries, the safety standard for evaluation for repurposing batteries (UL 1974) is published in 2018. In this paper, these standards (UL 1973 and UL 1974) are integrated and summarized for accelerating the advance of the battery energy storage system industry. | |
| ----- | |
| 隨著電動車輛的推廣與增加，汰役電池開始出現，未來數量將會快速增長，因此成為一個必須要解決的問題。這些動力電池在淘汰時，部分仍然有大約80% 的容量，顯然可以再次加以利用，例如做為儲能電池之使用。但由於是此類淘汰物品可能出現安全上的問題。Underwriters Laboratories (UL)公司原以電池儲能系統的安全標準UL 1973來因應此問題，但為面對汰役電池推廣之需求，於2018 年再度出版UL 1974二次利用電池安全評估標準。本文係參考UL 1973與UL 1974兩個標準，就電池儲能系統的發展現況，將這些標準加以整理與說明，供使用者參考，期能加速儲能電池系統的產業發展。",1,https://api.osf.io/v2/files/5db190fa743c23000c9f248e/,28,https://engrxiv.org/d4n3s/,10.31224/osf.io/d4n3s,,2019-10-24T13:56:06.077552,2019-11-13T15:20:52.960072 | |
| 6nw7f,"Behavior of Shewanella oneidensis MR-1 in a sulfur and zinc-rich medium and its applications for biosensing and biomaterials","An increasing focus of current microbiology research is the fact that some strains of bacteria, called dissimilatory metal-reducing bacteria (DMRB), are capable of utilizing certain metallic ions as terminal electron acceptors in their metabolic processes. One strain in particular, Shewanella oneidensis MR-1, can reduce ions of iron, lead, arsenic, and uranium, among others. Under anaerobic conditions it has also been shown to reduce sulfur compounds, nitrates, and chromates. The cultivation of DMRB under controlled conditions therefore has significant implications for the low-energy, room-temperature synthesis of metal sulfide and/or metal oxide semiconductors. Furthermore, Shewanella and other DMRB can form biofilms that interact electronically with solid-phase minerals in their environment. For this reason there exists a potential to grow DMRB directly into porous substrates in order to create biosensors that are capable of producing electrical signals that provide information about metal ion concentration in water as well as a range of other water quality variables.I will highlight my recent work exploring the behavior of Shewanella oneidensis MR-1, in a medium rich in both zinc and thiosulfate ions. I have grown Shewanella bacteria in a three-electrode system and used a potentiostat to hold the system at a fixed DC voltage during cultivation while also measuring current output. After completing the cultivation step, I have used cyclic voltammetry and electrochemical impedance spectroscopy to characterize the DC and AC current-voltage dynamics of the system, which can reveal the reduction-oxidation activity of key bacterial proteins. In the second experiment, I have grown Shewanella bacteria under both aerobic and anaerobic conditions in media rich in zinc and thiosulfate ions and used scanning electron microscopy and energy dispersive microscopy to characterize the minerals that precipitate within the batches. I compare results from a minimal medium containing only the zinc and thiosulfate sources to a more traditional Shewanella medium containing various vitamins, minerals and other nutrients to support growth. I also compare the inoculated batches to sterile control batches containing no bacteria in order to infer the effect that the bacteria have on mineralization in their environment. Finally, I use confocal microscopy to explore the fluorescence behavior of the precipitates generated in both inoculated and sterile batches.",1,https://api.osf.io/v2/files/5db091690db187000d39e4c6/,21,https://engrxiv.org/6nw7f/,10.31224/osf.io/6nw7f,,2019-10-23T19:23:30.702221,2019-10-23T19:23:45.944833 | |
| 38ktu,"Solar cooking potential in Switzerland : nodal modelling and optimisation","Solar cooking is one possible solution to reduce the domination of fossil fuel in the domestic sector and to benefit the renewable energy. This study assesses the solar cooking potential in Switzerland. A suited nodal model, based on energy balance equations of a box-type solar cooker is implemented in Matlab. Model parameters that cannot be determined experimentally or analytically are evaluated through an optimization procedure based on a Genetic Algorithm (GA). The model is able to predict the temperature of the cooking vessel with average relative error around 5%. Based on its reliability, the model is simulated over a year for different locations in Switzerland in order to determine the solar cooking potential. It is characterized by a metric which represents the number of days a year the oven could be used to cook potatoes for two persons. It is found that the cooking times of potatoes can be well predicted by an Arrhenius law with an activation energy of 74.14 kJ/mol. A potatoes cooking criterion is based on the Arrhenius equation and determines if the pot simulated temperature profile of a particular day allows to cook potatoes. The North-East of Switzerland is the least favourable area to solar cooking with theoretically around 155 cooking days per year. Around 240 cooking days are estimated in the Valais and the Grisons cantons, which represent a significant potential for solar cooking in Switzerland.",1,https://api.osf.io/v2/files/5db004960db187000e3984fd/,47,https://engrxiv.org/38ktu/,10.31224/osf.io/38ktu,,2019-10-23T14:12:00.345235,2019-10-23T18:26:44.749031 | |
| f9va7,"The Parenting Experience.: A Soul Machines like Demonstration(™)","Abstract: | |
| A virtual parenting experience, inspired by babyX of soul machines, as part of one’s digital life is explored as transcription from digital DNA. Algorithms are presented, using the open Daz3D framework with the Unity engine. An emphasis is placed on an anime reality and anime assets in creating the digital identity. A study on the role of loving kindness, compassion and natural education, humane education by real parenting, in the bringing up and the emergent digital personalities of virtual children is explored. | |
| Keywords: Natural Balance, parenting experience, alternatives to adoption, BabyX, Machine DNA | |
| What: | |
| Given the long waiting times and the legal formalities involved in adoption, to an end to a parenting experience, we present a virtual parenting experience based on a digital human on SaaS augmentation, with an emphasis on non physical reality , but an anime space, for an experience. Such experiences can be as realistic as a few decades long and are possible given the shift towards the cloud computing paradigm. We present a design for machine DNA based aging, parenting and bringing up, emphasising the natural balance, loving kindness and compassion, in alternative schooling, rather than a stick and carrot approach of reinforcement learning. | |
| How: | |
| We define a non linear time based template system based on the Genesis universal assets for male and female children, with a machine genome for the assets and define an aging model for uniform transcription with heuristics for social, spiritual, emotional and computational intelligence. | |
| Why: | |
| Given the extinction of many indigenous species, especially in Europe, Asia, Americas and the older Eurasia, is the need for machine evolution, the adoption of virtual parenting experiences and the knowledge of digital human identities. Can the parenting experience form a part of this identity, the need for the constant loving kindness, the warmth and humanity of human parenting. We explore this issue in this paper.",1,https://api.osf.io/v2/files/5dae220962b630000c6287e6/,25,https://engrxiv.org/f9va7/,10.31224/osf.io/f9va7,,2019-10-23T14:10:09.870102,2019-10-23T18:26:23.430428 | |
| yp2j7,"Critical Flow Centrality Measures on Interdependent Networks with Time-Varying Demands","This paper applies centrality measures based on critical flows to interdependent networks in which demands vary over time. These component importance measures combine classical flow centrality with concepts from critical infrastructure protection. In a previous work, the utility of critical flows was demonstrated on a flow network that represented a single infrastructure system with static demands. The present work considers the setting where multiple infrastructure systems are interlinked through physical and geospatial dependencies, and where demands for resources vary over time. Since critical flow measures are specific to flow patterns, and not to static network topology, the identification of critical elements requires statistical means. This paper demonstrates one such approach, leaving avenues open for future research. It also presents two forms of reliability analysis based on critical flows - a composite measure using edge reliability, and component failure/degradation analysis.",1,https://api.osf.io/v2/files/5dacdbd2d9fac4000aa68b34/,94,https://engrxiv.org/yp2j7/,10.31224/osf.io/yp2j7,,2019-10-21T02:48:08.968199,2019-10-30T23:55:43.695360 | |
| ksg2p,"Shear Wave Speeds Track Axial Stress in Porcine Collateral Ligaments","Ligament tension is an important factor that can affect the success of total knee arthroplasty (TKA) procedures. However, surgeons currently lack objective approaches for assessing tension in a particular ligament intraoperatively. The purpose of this study was to investigate the use of noninvasive shear wave tensiometry to characterize stress in medial and lateral collateral ligaments (MCLs and LCLs) ex vivo. Nine porcine MCL and LCL specimens were subjected to cyclic axial loading while wave speeds were measured using laser vibrometry. We found that squared shear wave speed increased linearly with stress in both the MCL (r2avg = 0.94) and LCL (r2avg = 0.98). Wave speeds were slightly lower in the MCL than the LCL when subjected to comparable axial stress (p < 0.001). Ligament-specific wave speeds may arise from differences in geometry and stress distributions between ligaments. These observations suggest it may be feasible to use noninvasive shear wave speed measures as a proxy of ligament loading during orthopedic procedures such as TKA.",1,https://api.osf.io/v2/files/5dab8893f1b0a9000a6485af/,21,https://engrxiv.org/ksg2p/,10.31224/osf.io/ksg2p,,2019-10-20T18:02:30.952447,2019-10-20T18:03:03.419628 | |
| 5wv2d,"A Rationale for Backprojection in Spotlight Synthetic Aperture Radar Image Formation","This note on backprojection for spotlight synthetic aperture radar image formation is mainly pedagogic in purpose and is intended to be accessible. The presentation is elementary and detailed, beginning with the wave equation and melding wave notions with signal processing notions using a compact and consistent notation throughout. A reflection model is developed including a general expression for the receiver signal which does not depend on a particular transmitted waveform. Then the signal is specialized to monochromatic waves to show how waves and the Fourier transform fit together. In the end the signal is once again generalized so that the theory works for any signal type. Backprojection is shown to reconstruct the wave field that was lost by sampling it at only one point, the receiving antenna. After specializing some details to the synthetic aperture radar geometry, the Projection Slice Theorem is introduced late, after an understanding of the underlying principles is obtained. Computational aspects are considered and it is seen that backprojection and direct Fourier inversion, also known as Polar Format Algorithm, are fundamentally the same, differing only in some implementation details, albeit significant ones, thus overturning the notion that backprojection is not a Fourier process. Those who might benefit from this paper include people who have worked in this field and who seek a somewhat different point of view from the usual presentation, people in other fields who are unfamiliar with some of the engineering concepts involved, and signal processing engineers who appreciate a bit of wave theory.",1,https://api.osf.io/v2/files/5daa72eff1b0a9000d651b3d/,57,https://engrxiv.org/5wv2d/,10.31224/osf.io/5wv2d,,2019-10-19T13:39:20.009838,2019-10-19T13:39:41.254271 | |
| 7dexn,"Brief Analysis of Aliasing in Polar and Keystone Formats for Spotlight Synthetic Aperture Radar","Keystone formatting [Doerry 2012] for spotlight synthetic aperture radar is an alternative to the popular polar format and reduces the computational burden of resampling the polar data to a rectangular grid before inverse Fourier transformation by a fast Fourier transform—-the polar format algorithm. After a brief review of relevant geometry and signals including linear frequency modulation and stepped sines, it is shown how to convert a polar-format radar into a keystone-format radar. Reconstructions from simulated data in both formats are shown and the differing kinds of image aliasing are examined.",1,https://api.osf.io/v2/files/5daa6eb8ec1775000efe76f4/,49,https://engrxiv.org/7dexn/,10.31224/osf.io/7dexn,,2019-10-19T13:37:15.142383,2019-10-19T13:37:41.774813 | |
| u3nej,"Biosynthesis of Molybdenum Disulfide Nanoparticles Using The Metal-Reducing Bacterium Shewanella Oneidensis MR-1","The bacterium Shewanella oneidensis MR-1 is a dissimilatory metal-reducing bacterium capable of performing anaerobic respiration using a metal as terminal electron acceptor. Isolated from Lake Oneida in Upstate New York, S. oneidensis MR-1 was first noted for its manganese-reducing capability, but has now been shown to reduce a range of metal ions such as Fe(III), Mn(IV), As(V) and Cr(VI), as well as sulfur anions such as thiosulfate and sulfite. In the lab, Shewanella has been grown anaerobically in media enhanced with sulfur and metal ions in order to produce several types of chalcogenide nanoparticles, such as zinc sulfide and arsenic trisulfide. | |
| Given the utility of chalcogenide materials for electronics and photonics applications, bacterially-synthesized chalcogenide nanoparticles present a tantalizing avenue for green chemistry. Compared to similar materials produced using traditional chemical synthesis methods, bacterially-synthesized nanomaterials can be produced at much lower temperatures and using fewer chemical reagents. This work presents a method of synthesizing molybdenum disulfide nanoparticles using S. oneidensis bacteria. Molybdenum disulfide is a layered semiconductor with an indirect band gap in its bulk state and a direct bandgap in its monolayer state. It also exhibits changes in its electronic properties when its surfaces are functionalized with molecules, giving it applications for both photodetection and biosensing. An anaerobic batch culture of S. oneidensis MR-1 was incubated at room temperature in the presence of molybdenum oxide, resulting in the production of molybdenum disulfide crystals less than a micron in diameter. These crystals were detected using scanning electron microscopy, transmission electron microscopy, absorbance spectroscopy and X-ray diffraction. In addition to confirming that molybdenum disulfide can be produced by Shewanella bacteria, the data collected using these methods provide insight on the size, morphology and photoresponse of nanoparticles generated this way. The findings also allow inferences to be made about how the confluence of several mechanisms present in an anaerobic Shewanella culture combine to make such a synthesis possible, while providing clues about how such processes can be further improved or extended to other materials.",1,https://api.osf.io/v2/files/5da8847e62b630000d5e6a76/,44,https://engrxiv.org/u3nej/,10.31224/osf.io/u3nej,,2019-10-17T15:30:48.820564,2019-10-23T17:51:55.818341 | |
| zqv5k,"An LCL power filter for grid connected micrcoinverter","This paper proposes to use an LCL filter on two-switch DC-DC flyback microinverter and its voltage for grid connected. With the proposed system, it could possible to improve the quality | |
| of the voltage injected into grid and also the quality of outlet power. However, this filter is never used before in the literature for this kind of microinverters. Using Matlab/Simulink software, the results obtained show a better quality of power energy and are in very great conformity with the IEEE1574 | |
| standards.",1,https://api.osf.io/v2/files/5da8504fec1775000efc8d80/,29,https://engrxiv.org/zqv5k/,10.31224/osf.io/zqv5k,,2019-10-17T14:10:05.781032,2019-10-17T14:10:22.831057 | |
| bue86,"Advancements in mechanical engineering spell hopeful development of autonomous biobots","In the case of injection gasoline engine, or better known as spark ignition engines, an effort to improve engine performance as well as to reduce fuel consumption is a fairly complex problem. Generally, engine performance improvement efforts will lead to increase in fuel consumption. However, this problem can be solved by implementing engine torque control based on intelligent regulation such as the fuzzy logic inference system. In this study, fuzzy logic engine torque regulation is used to control the throttle position entered by the driver to achieve optimal engine torque. An engine torque vs. throttle position and engine speed mapping for vehicles with economical function is used to build this control process regulation. From the simulation result, it can be concluded that this control strategy is very effective to reduce fuel consumption and simultaneously to optimize the engine performance.",1,https://api.osf.io/v2/files/5da82100ec1775000efc61a1/,22,https://engrxiv.org/bue86/,10.31224/osf.io/bue86,,2019-10-19T13:32:55.067646,2019-10-26T05:06:55.798713 | |
| b9xp7,"Improved Power Generation From PV Array Under Partial Shading Conditions by Shade Distribution Using Magic Square View Configuration","The main purpose of this paper is to model, simulate, and improve the performance of different 9 × 9 PV array configurations under different Partial Shading Conditions (PSCs) in order to extract the maximum power by defeat the mismatching power losses. Hence, PSCs reduces the performance of Photovoltaic (PV) arrays and increase the Local Maximum Power Points (LMPPs) on output | |
| characteristics P-V due to mismatching power losses between the PV panels. For this, Total-CrossTied (TCT) , and proposed Magic Square View (MSV) PV array topologies are considered for the study under Short Narrow shading patterns. PV array configurations enhancements and their | |
| investigations are carried out with regard to the comparison of the Global peak of outlet power (GP). | |
| The parameters of the PV array configurations are performed in MATLAB/Simulink software.",1,https://api.osf.io/v2/files/5da73e1d26eb50000d826a8b/,104,https://engrxiv.org/b9xp7/,10.31224/osf.io/b9xp7,,2019-10-16T16:51:30.025498,2019-10-16T18:47:02.216467 | |
| fh8m6,"Data-driven stochastic model for basin and sub-grid variability of SMAP satellite soil moisture","This study focused on the utility of coarse surface soil moisture observations for applications that require high resolution surface soil moisture information. This was accomplished by quantifying the information content of average soil moisture for three different spatial scales of 81 km2, 790 km2, and 4,400 km2. In situ point observations of soil moisture from 31 stations in Iowa were used to develop a spatial stochastic model that assumes hillslope-scale model parameters are independent. Soil moisture dry-downs and wetting regimes were analyzed using rain gauge and soil moisture sensor data. The statistical nature of dry-downs were parameterized using a power-law decay, and soil moisture increases due to rainfall were parameterized using a non-dimensional logistic curve that is a function of soil moisture deficit. The resulting stochastic model is used to quantify the magnitude of the standard deviation, σ(θ), and skewness G(θ) as a function of the areal average. We show that the greatest information content (small spatial standard deviation) of average observation corresponded to values near the minimum or the maximum soil moisture with σ(θ) < 5%, while average observations for intermediate soil moisture values had the lowest information content with σ(θ) > 20%. The differences in information content as a function of the areal average were consistent with the statistical nature of soil moisture that can be interpreted as small range bounded variable. However, this study provides quantitative estimates for the magnitude of the sub-grid and basin scale variability, documenting the utility for applications that require high resolution information. These results form the basis for the investigation of spatial runoff production in response to rainfall and to inform plot scale agriculture applications.",1,https://api.osf.io/v2/files/5da5f49626eb50000d812b63/,77,https://engrxiv.org/fh8m6/,10.31224/osf.io/fh8m6,10.1016/j.jhydrol.2019.06.026,2019-10-15T20:20:15.802129,2019-10-15T22:01:05.061558 | |
| vauf7,"Investigating the role of antecedent SMAP satellite soil moisture, radar rainfall and MODIS vegetation on runoff production in an agricultural region","Following results by Crow et al. (2017) [Geophys. Res. Lett. 44, 5495-5503] on the impact of antecedent soil moisture on runoff production, we investigate total runoff production during individual rainfall-runoff events in agricultural landscapes as a function of antecedent soil moisture, total rainfall, and vegetation cover for catchments with drainage areas ranging from 80-1000 km2 in the state of Iowa, USA. For our study, we use Enhanced SMAP soil moisture estimates, the MODIS enhanced vegetation index (EVI), gauge-corrected Stage IV radar rainfall, and USGS streamflow data. We analyze the event runoff ratio as a function of event-scale rainfall, antecedent SMAP soil moisture and soil-moisture-deficit-normalized rainfall for the events in a period from March 31, 2015 to October 31, 2018. Our goal is to confirm the relationships identified by Crow et al. (2017) in heavily managed agricultural landscapes and to refine some of their methodological steps to quantify the role of additional variables controlling runoff production. To this end, we define three different strategies to identify rainfall-runoff events and add a baseflow separation step to better insulate event scale stormflow runoff. We test the effects of antecedent soil moisture, rainfall, and vegetation on the event-scale runoff ratio. The antecedent SMAP soil moisture and event-scale rainfall are found to have significant predictive power in estimating event runoff ratio. Soil moisture deficit-normalized rainfall, introduced as the ratio of event-scale rainfall to available space in top soil before initiation of the event, exhibited a more distinct relationship with runoff ratio. The long-term analysis of runoff ratio, rainfall, and MODIS EVI indicated that, in an agricultural region, vegetation plays a significant role in determining event-scale runoff ratios. The methodology and outcome of our study have direct implications on real-time flood forecasting and long-term hydrologic assessments.",1,https://api.osf.io/v2/files/5da5f359a7bc73000bedc9ee/,84,https://engrxiv.org/vauf7/,10.31224/osf.io/vauf7,10.1016/j.jhydrol.2019.124210,2019-10-15T20:19:06.307485,2019-10-15T22:01:05.035498 | |
| uz85j,"Designing and analyzing two non-invasive current sensors using Ampere Force Law (AFL)","Here two different non-invasive current sensors are proposed, modeled and analyzed. The current sensors are based on the Ampere Force Law (AFL), defining the magnetic force between two parallel wire carrying currents. These current sensors can be used for detecting/sensing DC and AC currents as well as their combination in a single wire or multiple wires, and they do not rely on any permanent magnets for operation. In the first configuration, there are two microbeams, in which one of them is at the vicinity of the wire and undergoes the mechanical vibrations due to the magnetic force between the wire and the microbeam. The movement of the microbeam while it is generating a magnetic field induces a current inside another microbeam, which is stationary, as the output signal of the current sensor. In the second configuration, a single composite piezoelectric microbeam is used. The magnetic force between the wire and the piezoelectric microbeam leads the piezoelectric microbeam to move, thus it produces a voltage. Both configurations present extremely low power consumption, which is not dependent on the sensitivity of the current sensors. The dynamic response, sensitivity and power consumption of the current sensors are investigated, compared and discussed.",1,https://api.osf.io/v2/files/5da256e2fcf91f0012203df4/,124,https://engrxiv.org/uz85j/,10.31224/osf.io/uz85j,,2019-10-13T00:10:41.881871,2019-10-13T00:11:02.049678 | |
| 84enj,"Reactive Programming with the Interpreter pattern, automated parsers.","Reactive programming was popularized by Netflix, with a need for quick stream based processing, for a unified framework of event programming, with JavaX and the introduction of Beans for events and streams, a broad spectrum of applications for data driven, enterprise architectures, in the context of SaaS for a framework for many applications from ubiquitous computing to IIoT are described. | |
| This paper is on the formal automation of parsing in the three world scenario of CAS, OOPS and NLP, with a broad definition of algebras, programming languages and natural languages, for stream based event parsing. | |
| Keywords: CAS, OOPS, NLP, IIOT, ubiquitous computing, RxJava, Netflix, reactive Computing | |
| What: | |
| The interpreter design pattern is embedded in RxJava and RxJS to enable the parsing of arbitrary text files. We illustrate this with a SaaS based CDSS and Expert system, with the interpreter for parsing and automated persistence of Case Studies. | |
| How: | |
| We use an integrated SaaS based expert system using AWS for persistence and text mining. Pre processing is done by a RxJS based client web worker for pre-processing and parsing of case studies and persistence on AWS with Taskoids for rule creation and persistence. | |
| Why: | |
| The MetaECHO, of the University Of New Mexico is a knowledge democratization movement, to make available specialist practice based expert knowledge through online knowledge sharing and training. In an attempt to make specialist practice available through expert system based CDSS systems, Vayu Vaidya, a research organization, based in Seattle, WA, USA, and HIHT Dehradun, India, is in the process of creating AWS based expert systems to persist all the case studies, presented through the TeleECHO and MetaECHO program. | |
| So What: | |
| The expert system, with a conversational UI interface to a CDSS system, would make specialist knowledge available 24/7 to the medical community, coupled with the preventive medicine based risk evaluation and medical infotainment information available through Amazon Alexa and IFDB.",1,https://api.osf.io/v2/files/5da2071ef6b03e00101e9e42/,84,https://engrxiv.org/84enj/,10.31224/osf.io/84enj,,2019-10-13T00:18:46.674980,2019-10-13T00:19:03.287996 | |
| 8knwq,"Investigation the effect of anodization voltage on the geometrical properties and photocatalytic activity of TiO2 nanotube arrays for degradation of p-nitrophenol","p-nitrophenol (PNP) is a nitroaromatic compound that poses a potential environmental hazard because of its acute toxicity, high carcinogenicity, low biodegradability and cumulative effect. Titanium dioxide (TiO2) nanotubes have shown great potential as ideal and powerful photocatalysts in purification of polluted water due to their high photo oxidation, anti-fogging, nontoxicity, good chemical stability and low cost. Therefore, TiO2 nanotube arrays were fabricated by two-step anodization process at 30,40 and 50V; and were used in photocatalytic degradation of organic pollution p-nitrophenol. In order to have the crystal structure, nanotubes were annealed at 450 °C for 2 hours. Characterizing of TiO2 nanotubes were evaluated by FESEM, XRD and Spectrophotometry analyses. Effect of anodization voltage on nanotube’s length and diameter were investigated. The result showed that as anodization voltage increases from 30V to 50V, nanotube’s length, diameter and wall thickness increase linearly from 1.4 μm to 4.8 μm, 45 nm to 100nm and 15nm to 25 nm, respectively. Increasing in anodization voltage lead to enhancement in porosity (0.4-0.5) and roughness factor (109-194) of TiO2 nanotubes, respectively. By investigating kinetic of degradation of p-nitrophenol, it was observed that mechanism of photocatalytic degradation for all samples are followed first order kinetic. The results indicate that amongst all synthesized samples, 50 V sample with 38%, shows the most efficiency in degradation of p-nitrophenol under UV irradiation.",1,https://api.osf.io/v2/files/5da0c319a7bc73000bea7f22/,94,https://engrxiv.org/8knwq/,10.31224/osf.io/8knwq,,2019-10-12T00:00:28.954514,2019-10-12T00:00:46.521015 | |
| 3fykp,"Comparison Position of Solar PV System : College Learning Building South Lampung","Sunlight is energy that can be converted into electrical energy. One of the uses is by applying it to the roof of | |
| the building. The application in this building has restrictions such as the placement of the PV modules | |
| horizontally and vertically. In the study comparing the results of energy obtained from the PV system with | |
| horizontal and vertical positions with a standard degree angle in the direction of azimuth sunlight. Position | |
| using the horizontal produces more energy and reaches a performance ratio of more than 80%.",1,https://api.osf.io/v2/files/5d9feb77fcf91f00101c255c/,78,https://engrxiv.org/3fykp/,10.31224/osf.io/3fykp,,2019-10-12T00:03:15.324736,2019-10-12T00:03:45.622358 | |
| fj3xq,"Crevice corrosion","Today, there is a large number of accepted tests to study crevice corrosion phenomena. The different methodologies can be used for comparing and ranking alloys, quality control, assessing the effects of changes in manufacturing routes and alloy composition on crevice corrosion resistance, as well as in evaluations to determine critical temperatures and potentials and induction times. | |
| The goal of the chapter is to describe the various standard test methods available to the corrosion specialist as well as adaptations to study specific crevice corrosion parameters. The focus is on test methods developed by the ASTM Committee G-1 on corrosion of metals, but other procedures are also included. While the test principles have been applied to many alloy systems, the scope of the chapter is on stainless steels and nickel-based alloys.",1,https://api.osf.io/v2/files/5d9eadcba7bc73000be8bc64/,81,https://engrxiv.org/fj3xq/,10.31224/osf.io/fj3xq,,2019-10-10T11:05:25.533873,2019-10-10T11:15:42.875486 | |
| 9w84y,"Analysis of 2D Turbulence in a Taylor-Couette Flow","This work deals with the simulation of a 2D turbulence in Taylor-Couette flows. We investigate if a laminar flow acts as a global attractor in 2D for large Reynolds number, or do other stable states exist. Since in case of channel flows, the laminar flow seems to be a global attractor, the question is if shear flows themselves show such behavior in curved geometries. While working, another interesting physical observation was made about the non-monotonic relaxation to the laminar flow: Starting from values significantly higher than laminar, the total kinetic energy decreases to a lesser value and then grows back to give the laminar flow. This phenomenon is studied in some detail and a possible reason for this is then examined. The work also investigates | |
| the creation and destruction of vortices inside the domain and draws observations based on the sign of the vortices relative to the vorticity of the laminar flow. Since the creation and subsequent death of turbulence is a very interesting observation and can only be seen in 2D, it is studied extensively.",1,https://api.osf.io/v2/files/5d9e2688f6b03e000f1ca935/,103,https://engrxiv.org/9w84y/,10.31224/osf.io/9w84y,,2019-10-10T11:02:59.793052,2019-10-10T11:11:04.323783 | |
| 87y2r,"AWS and Automation: A Case study II","ISP content can be readily added using the AWS CLI, in the form of ASK CLI or SFB CLI, to an existing skill. We can add premium content, in a product list [P], or consumables [C] or a subscription [S]. Even other skill content can be integrated as a premium content. In this paper we introduce taskoid machine genome , TAISPv1.0 for ISP integration, as a case study in intent machine evolution and code generator modules, modules for JSON creation and JSON compiling on AWS S3 with restful state transfer. | |
| Keywords: Taskoids, AWS, Alexa Skills, JSON, Rest, microservices, ASK CLI, SFB CLI. | |
| What: | |
| We define premium content as [[S], [C], [P]], a list of subscriptions, consumables and products for premium content. We define the stack in cloud formation, for the integration of premium content, generation of JSON objects and the building and deployment of the skill in CI/CD. | |
| How: | |
| ASK CLI script to template for a JSON generator, integrated with a cloud formation stack. | |
| SFB CLI for ISP integration and JSON generation from an .abc content. | |
| AWS integration of embedded Alexa controls and commands as ISP, for IOT or mobile integration, with a cloud formation stack, similar to echosim.io. | |
| Why: | |
| ISP content helps monetize skills in the freemium model, providing essential basic content with optional premium content usually in the form of product or service promotions and/ or premium content. This helps raise profits for an organization, bring in brand loyalty and equity, increase customer equity and intend to purchase.",1,https://api.osf.io/v2/files/5d9e23b7f6b03e00101b4f4e/,104,https://engrxiv.org/87y2r/,10.31224/osf.io/87y2r,,2019-10-10T11:10:36.376325,2019-10-10T11:19:03.180829 | |
| 8gmch,"The influence of cell size on the mechanical properties of nanocellular PMMA","Solid-state foaming experiments are conducted on three grades of polymethyl methacrylate (PMMA). Nanocellular PMMA foams are manufactured with an average cell size ranging from 20 nm to 84 nm and a relative density between 0.37 and 0.5. For benchmarking purposes, additional microcellular PMMA foams with an average cell size close to 1 ìm and relative density close to that of the nanocellular foams are manufactured. Uniaxial compression tests and single edge notch bend tests are conducted on the PMMA foams. The measured Young's modulus and yield strength of the PMMA foams are independent of cell size whereas the fracture toughness of the PMMA foam increases with decreasing average cell size from the micron range to the nanometer range.",1,https://api.osf.io/v2/files/5d9af597080409000d9467f3/,131,https://engrxiv.org/8gmch/,10.31224/osf.io/8gmch,10.1016/j.polymer.2019.121805,2019-10-08T00:34:07.831080,2019-10-08T00:34:22.216936 | |
| 2jm53,"The mechanics of solid-state nanofoaming","Solid-state nanofoaming experiments are conducted on two polymethyl methacrylate (PMMA) grades of markedly different molecular weight using CO2 as the blowing agent. The sensitivity of porosity to foaming time and foaming temperature is measured. Also, the microstructure of the PMMA nanofoams is characterized in terms of cell size and cell nucleation density. A one-dimensional numerical model is developed to predict the growth of spherical, gas-filled voids during the solid-state foaming process. Diffusion of CO2 within the PMMA matrix is sufficiently rapid for the concentration of CO2 to remain almost uniform spatially. The foaming model makes use of experimentally calibrated constitutive laws for the uniaxial stress versus strain response of the PMMA grades as a function of strain rate and temperature, and the effect of dissolved CO2 is accounted for by a shift in the glass transition temperature of the PMMA. The maximum achievable porosity is interpreted in terms of cell wall tearing and comparisons are made between the predictions of the model and nanofoaming measurements; it is deduced that the failure strain of the cell walls is sensitive to cell wall thickness.",1,https://api.osf.io/v2/files/5d9aec16204594000c37b7ea/,108,https://engrxiv.org/2jm53/,10.31224/osf.io/2jm53,10.1098/rspa.2019.0339,2019-10-08T00:33:19.797988,2019-10-08T00:33:42.926673 | |
| e5wn3,"Damage assessment of CNT-doped composites through IR-thermography and electrical resistance measurement","Rooted in their heterogeneous microstructure, composite materials possess high strength-to-weight and stiffness-to-weight ratios, making them essential building blocks for a wide range of industrial applications. However, their complicated microstructure makes it difficult to predict the failure mechanism and residual life under varying external loads. The in-situ health monitoring system has received much attention in recent years as one of the promising solutions for the aforementioned limitations of composite material. In this research, we suggest a coupled health monitoring system where IR thermography and electrical resistance measurement are utilized simultaneously to diagnose the damage state of the composite materials during tensile testing. The deformation and failure timeline of GFRP under quasi-static tensile loading could be subdivided into three characteristic regions, here named as damage levels, characterized by i) elastic deformation without damage formation, ii) formation of distributed micro-damages, and iii) enlargement of concentrated damage. By employing a multiphysics simulation framework, we modeled the interplay between physical phenomena occurring in three damage stages, involving crack propagation, variation in the temperature profile and electrical resistance. The results also allowed us to have an estimation of the ‘damage stress(σD)’, a value that represents the onset of micro-damage, which has a negligible effect on the elastic properties, but might be dangerous under cyclic loading.",1,https://api.osf.io/v2/files/5d98b6720a0361000c0ce122/,158,https://engrxiv.org/e5wn3/,10.31224/osf.io/e5wn3,,2019-10-06T00:48:52.986765,2019-10-06T00:49:23.102452 | |
| trw3g,"Partial Packets in Wireless Networks: A Review","Data transmission in wireless networks is vulnerable to errors, due to the nature of wireless characteristics. As a result, corrupted packets are a common case in wireless data transmissions. Many techniques have been proposed to tackle these issues and one of the recommended techniques is the partial packet recovery (PPR) scheme. There are various existing PPR methods that have been proposed, in the last two decades, in wireless networks. In addition, recent works have shown the possibility of network coding along with its capabilities in recovering the partial packets. This paper presents a review study of PPR approaches in wireless networks. We classify the approaches into several groups based on the soft information in the PHY layer. Furthermore, we describe the PPR techniques that have used in each of these groups. Our studies found that there are twenty-four protocols have been proposed using PPR to improve the performance in wireless networks.",1,https://api.osf.io/v2/files/5d96b1860b9a8c000c2f5faf/,159,https://engrxiv.org/trw3g/,10.31224/osf.io/trw3g,10.1049/iet-com.2019.0550,2019-10-04T23:27:42.389205,2019-11-13T02:47:58.096316 | |
| gmzn5,"Algorithmic-Information Theory interpretation to the Traveling Salesman Problem","The Traveling Salesman Problem (TSP) is a important optimization problem in computer science, mathematics and logistics. It belongs to the class of NP-Hard problems and can be very time consuming to find solutions to large instances with guarantee optimality. As number of city-nodes in the graph increases, the amount of valid route tours also growths rapidly and thus requiring considerable time to evaluate and classify each permutation. The objective of the heuristic process is to search the solution space for the optimal solution while maximizing the attached utility-cost function (i.e. finding the shortest euclidean distance tour) and minimizing the computational time complexity of the algorithm. | |
| Many complex real world scenarios can be reduced to a simulation of a salesman trying to find the shortest (length) Hamiltonian (cycle) route in a euclidean super-graph G*. If each city-node is modeled as a input symbol in a communication channel represented by an output pair with consistent probabilities distribution thus an polynomial-time probabilistic algorithm can use this information to improve the solution quality at the same rate of transmission of information over the channel. | |
| In this paper we explore an quantitative stochastic process based in Algorithm Information Theory and the Shannon-Kelly criterion to find valid near optimal solutions using a new growth- optimal strategy applied to the TSP problem that have statistically significant transmission rate even when no encoding scheme is available, regardless of time-complexity of the problem. | |
| Previous heuristics such as 2 opt, Genetic Algorithms (GA) and Simulated Annealing (SA) approach’s the TSP problem by relying on a priori knowledge about the data distribution in order to reduce the probability of error in finding the best candidate solution tour. | |
| In this work we propose a method that models the solution space boundaries of the TSP problem as a communication channel by means of Information Theory. We describe a search algorithm that check for patterns (i.e information content) in the elements of a constrained solution space modeled as messages transmitted through communication systems. The boundaries of the search space are defined by the Kolmogorov complexity of the candidate solutions sequences. We conclude with an discussion about the quality of the results and implications for general decision problem in Turing machines.",1,https://api.osf.io/v2/files/5d96a1a767b5c50012d8655e/,159,https://engrxiv.org/gmzn5/,10.31224/osf.io/gmzn5,,2019-10-04T23:25:40.633855,2019-10-04T23:26:04.867926 | |
| mgnx2,"Effective design of in-home displays","Demand-side management is widely considered a key tool to achieve the decarbonization on the energy sector. In this regard, providing end users with detailed information about their consumption patterns is key in order to enable them to make informed decisions to reduce or adapt their energy consumption. This requires the deployment of feedback interactive technologies such as in-home displays, dedicated apps/web portals, or ambient interfaces. There have been extensive research and numerous pilot experiences on the effect of these technologies on end-user behavior, which identified the importance of an appropriate device design to achieve the desired demand response. However, a clear framework to design these feedback technologies in order to ensure the desired behavioral change does not exist. | |
| In order to fill this gap, this paper presents an exhaustive review of existing research on feedback, focusing especially on interactive devices. This review has resulted in the identification of ten key parameters that should be taken into account by device designers, including the type and form of the information provided (medium, units, disaggregation level, comparisons, goal setting), design of the interface and devices themselves, the possible inclusion of penalties and rewards, and privacy concerns. Recommendations to implement them in such a way that end-user interaction and response is maximized are provided. These recommendations would jointly make in-home displays more effective in creating the desired household behavioral change to maximize energy conservation. Moreover, critical areas where further research is necessary before a sound recommendation can be made are identified.",1,https://api.osf.io/v2/files/5d961b88055eda000a3b44c2/,141,https://engrxiv.org/mgnx2/,10.31224/osf.io/mgnx2,10.1016/j.rser.2019.109301,2019-10-03T17:24:06.700820,2019-10-04T08:24:10.800942 | |
| ad8en,"Migration from POW to POS for Ethereum","Block-chain is rapidly evolving. There are continuous enhancements. In order to validate transactions algorithm is used. The traditional approach of Proof of Work (POW) is where miners are incentivized to compete with each other to complete transactions. Alternate system is proof of stake (POS) where in the validators lock up some of their tokens and thus replace the role of miners. Generation three block chain, which are the latest and fastest ones are mostly Proof of Stake (POS). Hence the POW systems seek to leverage the POS properties in order to attain higher speed and scalability. The paper discusses the approach with Ethereum has taken to migrate from the current POW protocol to POS protocol. The concept of Caster is focused as implementation. Casper further has two subtypes of approaches know as Friendly Finality Gadget (FFG) and Correct by Construction (CBC). The paper discusses on safety guard over these algorithms.",1,https://api.osf.io/v2/files/5d92e9f3c8a75d001664b745/,125,https://engrxiv.org/ad8en/,10.31224/osf.io/ad8en,,2019-10-01T14:22:23.474514,2019-10-06T07:34:41.047791 | |
| w9m4y,"Analysis of the efficiency of wind turbine gearboxes using the temperature variable","The aim of this paper is to evaluate how lubricant selection affects gearbox efficiency and overall energy production by analysing real data from wind farms, monitored and controlled by a Supervisory Control and Data Acquisition (SCADA system). The turbines analysed worked with two or more oil types for the same amount of hours, which allowed to establish relations between the active power curves and wind velocity; oil temperature inside gearboxes and wind velocity; and oil temperature inside gearboxes and active power production. The results of this study evidenced a direct relation between oil characteristics and energy efficiency i.e. gearboxes working with mineral oil perform better then gearboxes working with synthetic oils. Those differences can be significant in terms of active power production. Also, it was observed oil degradation as function of temperature increase, with changes on viscosity, which reveals that temperature behaviour along the active power curve is strongly related to oil’ characteristics.",1,https://api.osf.io/v2/files/5d91cbeac8a75d0018649d51/,133,https://engrxiv.org/w9m4y/,10.31224/osf.io/w9m4y,10.1016/j.renene.2018.12.040,2019-09-30T14:05:38.989770,2019-10-01T01:46:22.249324 | |
| e24rb,"A scalable and modular Material Point Method for large-scale simulations","In this paper, we describe a new scalable and modular material point method (MPM) code developed for solving large-scale problems in continuum mechanics. The MPM is a hybrid Eulerian-Lagrangian approach, which uses both moving material points and computational nodes on a background mesh. The MPM has been successfully applied to solve large-deformation problems such as landslides, failure of slopes, concrete flows, etc. Solving these large-deformation problems result in the material points actively moving through the mesh. Developing an efficient parallelisation scheme for the MPM code requires dynamic load-balancing techniques for both the material points and the background mesh. This paper describes the data structures and algorithms employed to improve the performance and portability of the MPM code.",1,https://api.osf.io/v2/files/5d913345c8a75d0017662e1e/,30,https://engrxiv.org/e24rb/,10.31224/osf.io/e24rb,,2019-09-29T23:22:22.227387,2019-09-29T23:27:03.459381 | |
| 2qxpe,"Free space transmission lines in receiving antenna operation","This work derives exact expressions for the voltage and current induced into a two conductors non isolated transmission lines by an incident plane wave. The methodology is to use the transmission line radiating properties to derive scattering matrices and make use of reciprocity to derive the response to the incident wave. The analysis is in the frequency domain and it considers transmission lines of any small electric cross section, incident by a plane wave from any incident direction and any polarisation. The analytic results are validated by successful comparison with ANSYS commercial software simulation results, and compatible with other published results.",1,https://api.osf.io/v2/files/5d90a466c43280001bc5578f/,117,https://engrxiv.org/2qxpe/,10.31224/osf.io/2qxpe,,2019-09-29T15:13:31.414697,2019-09-29T15:13:46.982457 | |
| rcygq,"Evolution of Microstructures on Stainless Steel induced by Ultra-Short Laser Ablation","Ultra-short pulsed laser ablation of stainless steel is accompanied by the evolution of different microstructures. Depending on the fuence, accumulated energy and number of laser passes cones from impurities, laser induced periodic surface structures and conelike protrusion (CLP) evolve at the surface. These often unwanted morphologies can be inhibited by carefully choosing the strategy and laser parameters. Here, the identifed region shows a small processing window for | |
| designed 515nm sub 1 ps ablation leading to low surface roughness. CLP are still not well understood and here a pre-cursor structure is reported. Subsequently, the CLP growth is grain orientation and polarization dependent and studied in more depth. Preferentially, CLP start to evolve at the (101) grain orientations with linear polarized laser radiation. Moreover, a nanoindentation study reveals robust mechanical properties, which could be beneficial for tribology applications in the hydrodynamic regime.",1,https://api.osf.io/v2/files/5d8d04784ab86b0018f15ea0/,159,https://engrxiv.org/rcygq/,10.31224/osf.io/rcygq,,2019-09-26T20:31:44.474728,2019-09-27T00:37:48.390035 | |
| 863un,"Short and Spaced Twisted Tapes to Mitigate Fouling in Tubular Membranes","Static mixers are an efficient means to mitigate membrane fouling as they deflect the fluid, thus increasing the shear rate at the membrane surface and enhancing back-transport of rejected matter. However, inserting static mixers in the flow channel of a membrane imposes an additional pressure drop. To decrease this detrimental effect of static mixers, we shorten twisted tape mixers and investigate how this shortening translates into a reduction of fouling mitigation. We follow two approaches known from heat transfer enhancement: i) shorten the total length of the twisted tape and ii) use regularly spaced short twisted tape elements which are kept at their position by smooth rods placed in between the twisted elements. Computational fluid dynamics (CFD) is applied to analyze the flow pattern, the shear rate at the membrane and the resulting pressure drop. The results allow for the selection of modified twisted tape mixers with lower pressure loss, but sufficient flow properties for fouling mitigation. The most promising mixer designs were selected according to the CFD study, 3D-printed, and their fouling mitigation effect experimentally investigated using silica suspensions. Additionally, the effect of foulant concentration in this system is analyzed. For low silica concentrations (0.03 g/L) the short and spaced twisted tapes mitigate fouling as efficiently as the full-length twisted tape. At high silica concentrations and fluxes, the full-length mixer mitigates fouling more strongly than the short and spaced twisted tapes. However, the modified twisted tapes prove to be more energy-efficient up to a certain fouling exposure.",1,https://api.osf.io/v2/files/5d8b2c90b3c37400189e8d1f/,131,https://engrxiv.org/863un/,10.31224/osf.io/863un,10.1016/j.memsci.2019.117426,2019-09-25T13:38:40.713757,2019-09-25T13:39:05.576671 | |
| fjym3,"The study of progressive collapse in dual systems","Throughout this paper, progressive collapse of steel structure with dual system considering the removing column scenario is studied. Due to this objective, two lateral load resisting systems, are modeled in ABAQUS software with omitting various columns, and the performance of systems against progressive collapse are compared with each other. The results represent that whenever a structure is experiencing an unusual external load such as the collision of a vehicle, the most critical columns are those placed at the nearest external frame of the structure. Thus, these members should be considered as highly important members because they could play a significant role in progressive collapse potential reduction as key members.",1,https://api.osf.io/v2/files/5d8aecb4b3c374001b9c2449/,106,https://engrxiv.org/fjym3/,10.31224/osf.io/fjym3,,2019-09-25T13:37:13.266005,2019-09-25T13:38:02.702081 | |
| xzmby,"QUANTUM ANNEALING OPTIMIZATION OF A HEURISTIC SURROGATE MODEL FOR PWR FUEL LOADING","An efficient fuel arrangement must be generated by PWR operators every 6–18 months. This complex problem has been extensively researched with two broad approaches, heuristic and stochastic methods becoming accepted. This initial study qualitatively introduces the concept of encoding full-core PWR fuel loading patterns into a form suitable for quantum annealing. The concepts of adiabatic quantum computers and quantum annealing are introduced and a surrogate model encoding of a set of heuristics for loading pattern design produced in a form suitable for use in present-day quantum annealers. The simulated results show significant similarity to benchmark loading patterns.",1,https://api.osf.io/v2/files/5d89fd6853713d001a1d8dea/,140,https://engrxiv.org/xzmby/,10.31224/osf.io/xzmby,,2019-09-24T13:56:47.083364,2019-09-25T13:21:40.572613 | |
| aq3dt,"SURROGATE MODEL OPTIMIZATION OF A ‘MICRO CORE’ PWR FUEL ASSEMBLY ARRANGEMENT USING DEEP LEARNING MODELS","This paper investigates the applicability of surrogate model optimization (SMO) using | |
| deep learning regression models to automatically embed knowledge about the objective function into the optimization process. This paper demonstrates two deep learning SMO methods for calculating simple neutronics parameters. Using these models, SMO returns results comparable with those from the early stages of direct iterative optimization. However, for this study, the cost of creating the training set outweighs the benefits of the surrogate models.",1,https://api.osf.io/v2/files/5d89f95653713d001a1d8974/,139,https://engrxiv.org/aq3dt/,10.31224/osf.io/aq3dt,,2019-09-24T13:55:58.088590,2019-09-28T17:35:28.834540 | |
| bf3du,"Aerocapture Performance Analysis for a Neptune Mission Using a Heritage Blunt-Body Aeroshell","The large navigation and atmospheric uncertainties at Neptune have historically driven the need for a mid-lift-to-drag L/D vehicle with L/D of 0.6--0.8. All planetary entry vehicles flown to date are low-L/D blunt-body aeroshells with L/D less than 0.4. The lack of a heritage mid-L/D aeroshell presents a long pole for Neptune aerocapture, as the development and testing of a new entry vehicle incurs significant cost, risk, and time. Techniques which may allow Neptune aerocapture to be performed using heritage low-L/D blunt-body aeroshells are investigated, and obviate the need for mid-L/D aeroshells. A navigation study is performed to quantify the delivery errors, and a new guidance algorithm with on-board density estimation is developed to accommodate atmospheric uncertainties. Monte Carlo simulation is used to analyze aerocapture performance of a vehicle with L/D = 0.4. One hundred percent of the cases captured successfully and show a 99.87% probability of achieving the desired science orbit with a total of 396 m/s propulsive Delta V budget, even with worst-case atmospheric uncertainties.",1,https://api.osf.io/v2/files/5d84e8e151eeee0017bc62b5/,154,https://engrxiv.org/bf3du/,10.31224/osf.io/bf3du,,2019-09-20T20:16:26.240674,2019-09-20T20:16:43.651496 | |
| v74eq,"Mining Minimal Map-Segments for Visual Place Classifiers","In visual place recognition (VPR), map segmentation (MS) is a preprocessing technique used to partition a given view-sequence map into place classes (i.e., map segments) so that each class has good place-specific training images for a visual place classifier (VPC). Existing approaches to MS implicitly/explicitly suppose that map segments have a certain size, or individual map segments are balanced in size. However, recent VPR systems showed that very small important map segments (minimal map segments) often suffice for VPC, and the remaining large unimportant portion of the map should be discarded to minimize map maintenance cost. Here, a new MS algorithm that can mine minimal map segments from a large view-sequence map is presented. To solve the inherently NP hard problem, MS is formulated as a video-segmentation problem and the efficient point-trajectory based paradigm of video segmentation is used. The proposed map representation was implemented with three types of VPC: deep convolutional neural network, bag-of-words, and object class detector, and each was integrated into a Monte Carlo localization algorithm (MCL) within a topometric VPR framework. Experiments using the publicly available NCLT dataset thoroughly investigate the efficacy of MS in terms of VPR performance.",1,https://api.osf.io/v2/files/5d843096305a6800170b27cf/,107,https://engrxiv.org/v74eq/,10.31224/osf.io/v74eq,,2019-09-20T02:52:22.831419,2019-09-20T02:52:43.083963 | |
| qhgcx,"Fault-Diagnosing SLAM for Varying Scale Change Detection","In this paper, we present a new fault diagnosis (FD) -based approach for detection of imagery changes that can detect significant changes as inconsistencies between different sub-modules (e.g., self-localization) of visual SLAM. Unlike classical change detection approaches such as pairwise image comparison (PC) and anomaly detection (AD), neither the memorization of each map image nor the maintenance of up-to-date place-specific anomaly detectors are required in this FD approach. A significant challenge that is encountered when incorporating different SLAM sub-modules into FD involves dealing with the varying scales of objects that have changed (e.g., the appearance of small dangerous obstacles on the floor). To address this issue, we reconsider the bag-of-words (BoW) image representation, by exploiting its recent advances in terms of self-localization and change detection. As a key advantage, BoW image representation can be reorganized into any different scaling by simply cropping the original BoW image. Furthermore, we propose to combine different self-localization modules with strong and weak BoW features with different discriminativity, and to treat inconsistency between strong and weak self-localization as an indicator of change. The efficacy of the proposed approach of FD with/without combining AD and/or PC was experimentally validated.",1,https://api.osf.io/v2/files/5d84260b305a6800160b8fae/,152,https://engrxiv.org/qhgcx/,10.31224/osf.io/qhgcx,,2019-09-20T02:50:44.368395,2019-09-20T02:51:02.809389 | |
| u945r,"LIMITED RESOURCES OPTIMIZATION OF HEALTH CARE SERVICES WITH A LINEAR INTEGER PROGRAMMING APPROACH","If the availability of resources in the service center is very adequate, services can be carried out optimally, but we cannot be sure in this situation and even if excessive resources can also result in wasteful costs. If the number of requests more than the number of resources available at the service center can result in non-fulfillment of service requests, this can lead to a long queue of service requests, and if the demand for health care comes from an emergency patient (prioritized patient) can definitely cause this problem to die need to be handled better so as not to cause harm to service providers and patients as service recipients. Health service requests by patients that provide information about the location and type of service desired will be received by the service provider / server connected to the internet service, so that health care request information can be scheduled by the server (hospital health). Communication between the resources available on the server allocates time for each health service that maximizes the limited use of resources to meet the patient's health service needs. The purpose of this study is to simulate the Smart Health model on health services using linear integer programming, so that the resulting model can solve the problem of limited available resources that can serve all requests so that services and services can be done quickly, so as to reduce the risk of losing lives or risks that can endanger the patient. From the new models produced, this maximizes health services and minimizes the time of arrival of medical personnel at the place of request, where when patients request treatment for medical care from the hospital, health care will be provided according to the patient's request.",1,https://api.osf.io/v2/files/5d8414bd51eeee0019ba7d9e/,137,https://engrxiv.org/u945r/,10.31224/osf.io/u945r,,2019-09-20T02:48:31.485264,2019-09-20T02:48:43.095246 | |
| 3smqp,"Voltage dip diagnosis in electrical distribution systems using extreme learning machines: an empirical evaluation","An inefficient operation of the utility grid can be inferred from low power quality indexes. Under such conditions, reductions in the useful life of equipments and loads, grid instabilities, service interruptions and breakdowns can be expected, which would produce meaningful economic losses for the end-users as well as for the power supply company. In this context, it is useful to have a diagnosis tool able to identify the underlying cause of a given disturbance. This article proposes a one-step extreme learning machine-based method for the diagnosis of voltage dips detected on an electrical distribution grid. The proposed method was evaluated on the basis of synthetic data generated by the simulation of a real power grid. The performance of 10 hyperparameter combinations on the diagnosis of 20 different classes of voltage dips was assessed through two different strategies, i.e.: 1) a one-for-all approach, with a common classifier for all disturbance classes; and 2) a one-against-all approach, with a classifier per disturbance class. It was proven that strategy 2) has a better generalization ability and lower training and testing times. The obtained results suggest the potential of the proposed approach for power quality disturbance diagnosis, and open the challenge of formulating further hypotheses to be assessed.",1,https://api.osf.io/v2/files/5d82aaf5b3714e001886c68c/,207,https://engrxiv.org/3smqp/,10.31224/osf.io/3smqp,,2019-09-19T19:32:57.982801,2019-09-19T19:33:22.537079 | |
| nyqug,"Effective Plans for Hospital System Response to Earthquake Emergencies","Hospital systems play a critical role in treating injuries and preventing additional deaths during disaster emergency response. Natural disasters hinder the ability of hospital systems to operate at full capacity. Therefore, it is important for cities to develop policies and standards that enable hospitals' continuous operations to provide patients with timely treatment and ensure urban resilience. Here, we present a methodology to evaluate emergency response based on a probabilistic model that assesses the loss of hospital functions and quantifies multiseverity injuries as a result of earthquake damage. The proposed methodology is able to design effective plans for patient transferal and allocation of medical resources using an optimization formulation. This methodology is applied to Lima, Peru, subjected to a disaster scenario based on the M 8.0 earthquake that occurred there in 1940. Our results show that the spatial distribution of health service demands mismatches the post-earthquake capacities of hospitals, leaving large zones on the periphery of Lima significantly underserved. This study demonstrates how emergency plans that leverage hospital-system coordination can address this demand-capacity mismatch, enabling effective patient transfers, ambulance usage, and deployment of emergency medical teams.",1,https://api.osf.io/v2/files/5d8286aeb3714e001986ac60/,179,https://engrxiv.org/nyqug/,10.31224/osf.io/nyqug,,2019-09-19T19:30:25.980391,2019-09-19T19:30:44.522162 | |
| y6dut,"Designing A Protective Relay for Differential Protection of Power Transformers Using Clarks Transform and S Transform","Given that power transformers are one of the most important components of each network, their protection is an important part that the power transformer errors must be accurately identified and distinguished from each other. Therefore, identification and differentiation of transient phenomena of power transformers, including internal and external errors and magnetic inrush current are essential. In this research, Clarke transform and S transform were used to distinguish between these phenomena that the proposed algorithm is very suitable in terms of three characteristics of accuracy, speed and computational cost. Initially, the simulation of internal, external errors and magnetic inrush current of the transformer was performed for different transformer scenarios. For this purpose, 1060 signal tests were performed under different conditions. Subsequently, the signals of differential current obtained by Clarke transformation and S transformation were analyzed and appropriate criteria were extracted for detecting the current of internal errors from external errors and inrush current. The simulated internal and external errors include three- phase, three-phase to ground, two- phase, two- phase to ground and phase to ground error. Simulations were performed using PSCAD software and implementation of the proposed algorithm in MATLAB environment. The results of this study prevent the unwanted performance of differential protection to prevent undesirable electrifying. It is clear that the description of transient phenomena is the first step towards improving new ideas and criteria for protection with the greater reliability of power transformer which can be controlled better such unusual conditions that are currently used in equipment and relay.",1,https://api.osf.io/v2/files/5d815c289defac001a19b4a5/,139,https://engrxiv.org/y6dut/,10.31224/osf.io/y6dut,,2019-09-18T01:32:22.381500,2019-09-18T01:32:45.883992 | |
| 4cjq2,"Design Report ISWTC 2019","The objective of this report is to study and design a small wind turbine for the International Small Wind Turbine Competition 2019. A team was composed for this task from multiple disciplines and at different stages of their study. Later on, sub-teams were formed and tasks were divided and distributed to the team members depending on their affinity, knowledge and skill expertise. The tasks mainly involved the design of elements, material selection, design calculations, software simulation tests, and design documentation.",1,https://api.osf.io/v2/files/5d80a8d1710c95001d5bee68/,84,https://engrxiv.org/4cjq2/,10.31224/osf.io/4cjq2,,2019-09-17T13:52:27.799430,2019-09-30T11:00:48.073845 | |
| dth7v,"Computational Analysis of High Lift Generating Airfoils for Diffuser Augmented Wind Turbines","The present study aims to asses the aerodynamic performance of Diffuser Augmented Wind Turbine (DAWT) using high lift generating airfoils in the construction of the shroud/diffuser. The study is a Computational Fluid Dynamics (CFD) analysis which is carried out using Reynolds Averaged Navier-Stokes (RANS) simulations. The flow across the duct and rotor blades, which are modeled as an actuator disk (AD), is analyzed. Various High-Lift generating airfoils and their geometries were taken into consideration and analyzed with additional geometric modifications, such as a flange, to improve flow through the AD and increase the augmentation factor",1,https://api.osf.io/v2/files/5d80972dfcbf44001c478d5c/,101,https://engrxiv.org/dth7v/,10.31224/osf.io/dth7v,,2019-09-17T13:51:47.678183,2019-09-22T15:21:23.174167 | |
| kzbcr,"The Potential for Ducted Wind Turbines in an Urban Environment","This article discusses the applicability of Ducted Wind Turbines for decentralized energy generation in an urban environment. Ducted Wind Turbines overcome various constraints posed by urban infrastructure including reduced wind speed, effect of the atmospheric boundary layer as well as lesser space availability. Ducted Wind Turbines present a new way of sourcing energy at a local level, aiding community based models of energy distribution and consumption. The main aim of the present letter is to propose Ducted Wind Turbines as a precursor for energy production in urban, peri-urban as well as rural areas around the world.",1,https://api.osf.io/v2/files/5d8089fa710c95001d5bd4cb/,145,https://engrxiv.org/kzbcr/,10.31224/osf.io/kzbcr,,2019-09-17T13:50:42.433843,2019-09-17T14:05:42.131952 | |
| mypt7,"Vigilance Enhancement Using Traditional Methods: A Review","This paper presents a review on vigilance enhancement using traditional methods and discusses their contradictory findings. The review highlights the key differences between research findings and argues that individual differences could be a significant contributing factor to the controversial results. In this paper, we found that, traditional enhancement methods are reliable and have significant effects on reducing vigilance decrement. The paper discusses the challenges toward the enhancement techniques and provides evidence to use the traditional enhancement on vigilance studies, regardless of their variations with individual differences.",1,https://api.osf.io/v2/files/5d7f465e710c95001d5ac51e/,60,https://engrxiv.org/mypt7/,10.31224/osf.io/mypt7,,2019-09-16T16:09:41.986698,2019-09-16T16:10:07.715405 | |
| p5wg9,"Micromechanics-based prediction of the effective properties of piezoelectric composite having interfacial imperfections","We derive an analytical expression to predict the effective properties of a particulate reinforced piezoelectric composite with interfacial imperfections using a micromechanics based mean–field approach. We correctly derive the analytical formula of the modified Eshelby tensor, the modified concentration tensor, and the effective property equations based on the modified Mori–Tanaka method in the presence of interfacial imperfections. Our results are validated against finite element analyses (FEA) for the entire range of interfacial damage levels, from a perfect to a completely disconnected and insulated interface. For the facile evaluation of the nontrivial tensorial equations, we adopt the Mandel notation to perform tensor operations with 9 x 9 symmetric matrix operations. We apply the method to predict the effective properties of a representative piezoelectric composite consisting of PVDF and SiC reinforcements.",1,https://api.osf.io/v2/files/5d7eea7c9defac001818f00d/,47,https://engrxiv.org/p5wg9/,10.31224/osf.io/p5wg9,,2019-09-16T16:06:55.900978,2019-09-16T16:07:23.763493 | |
| kawxb,"Vigilance Enhancement Using Computerized Techniques","This paper presents a review on vigilance enhancement using computerized means and discusses their contradictory findings. It highlights the key differences between research findings and argues that variations in experimental protocol could be a significant contributing factor to the controversial results. In this paper, we found that, computerized means of enhancement are reliable and have significant effects on reducing vigilance decrement. The paper discusses the challenges toward the enhancement techniques and suggests several alternative strategies to reduce vigilance decrement. Furthermore, this review provides evidence to use computerized means of enhancement on vigilance studies, regardless of their practical challenges.",1,https://api.osf.io/v2/files/5d7e3d7a7483ec001952038a/,195,https://engrxiv.org/kawxb/,10.31224/osf.io/kawxb,,2019-09-15T16:05:44.280514,2019-09-15T16:06:02.798024 | |
| xtacw,"A Unified Framework for Aerocapture Systems Analysis","A unified framework for aerocapture systems analysis studies is presented, taking into account the interconnected nature of interplanetary trajectory design and vehicle design. One of the limitations of previous aerocapture systems studies is their focus on a single interplanetary trajectory for detailed subsystem level analysis. The proposed framework and aerocapture feasibility charts enable a mission designer to perform rapid trajectory and vehicle design trade-offs, and is illustrated with its application to a Neptune mission. The approach can be applied to other atmosphere-bearing Solar System destinations. The framework can be be implemented in an aerocapture software suite to enable rapid mission design studies.",1,https://api.osf.io/v2/files/5d7d298a9defac0017198186/,195,https://engrxiv.org/xtacw/,10.31224/osf.io/xtacw,,2019-09-14T20:15:02.328947,2019-09-14T20:15:23.006793 | |
| xzg7k,"Sense- boarding algorithm in superscalar, scalable multicore and data-inspired processors.","A new algorithm of data dependencies and ILP is defined with the sense index of a thread in true-parallelism(™), from the definitions of Quasi-Parallelism, which is the sensitivity and sense indices defined for true scalability between single/multi-cores. The application to the CUDA architecture is delineated in formal architectural definitions. | |
| Keywords: CUDA architectures, superscalar, ILP, data prediction, sense sensitivity index. | |
| What: | |
| Out of order processing in a pipeline, can be optimized with the sense-boarding processor. | |
| In this single to multi-core scalable architecture, the processor is thread-centric with sleeping and active threads. Sleeping threads have a sense() function associated with them. Unlike their human counterparts, snoring is a useful feature that helps keep sensitive threads awake and running. sense-boarding is a scheduling algorithm that tracks the sensitivity indices of threads to snoring and helps schedule threads with dependency relationships for out of order execution. | |
| How: | |
| sense boarding is a board based dependency for instruction-level parallelism in multi-thread vector processing in out of order single-core/multicore symmetries. | |
| Inter thread dependencies of data are marked in a board data-structure by maps to define sensitivity and sense indices, sense functionality is useful in the case of dependencies, resource waiting and speculative execution or in data generation and prediction. sense determines the relationship in instruction-level parallelism, to sensitive out of order and data speculation. The application to the CUDA architecture for stream processing in GPUs is also mentioned. | |
| Algorithms are: | |
| Instruction level parallelism in sense-sensitivity index metrics: | |
| Data speculation , dirty caches, parallel pipeline algorithms. | |
| Scalability in single core/ multi core implementations. | |
| CUDA multi core architectures for stream speculation and instruction level parallelism. | |
| Why: | |
| Sleep is rest, and sense a measure of thread parallel-ness. While threads sleep for the right time, the awake ones perform in quasi-parallelism as HPC. Asynchronous with Lamport clocks.",1,https://api.osf.io/v2/files/5d7bdcf6fcbf44001b4579aa/,984,https://engrxiv.org/xzg7k/,10.31224/osf.io/xzg7k,,2019-09-13T19:42:26.920214,2019-09-13T19:42:45.598411 | |
| qg8er,"Study of Interactive Systems Based on Brain and Computer Interfaces","Scientists have always been looking for ways to create an effective relationship between humans and the machine, so that this relationship is as close as possible to human relationships, since even the most sophisticated machines do not have any particular effect without human intervention. This association results from brain-generated neural responses due to motor activity or cognitive activity. Communication methods include muscle and non-muscle activities that create brain activity or brainwaves and lead to a hardware device to perform a specific task. BCI was originally designed as a communication tool for patients with neuromuscular disorders, but due to recent advances in BCI devices such as passive electrodes, wireless headset, adaptive software, and cost reduction, it has been used to link the rest of the body. The BCI is a bridge between the signals generated by thoughts in our brain and the machines. BCI has been a successful invention in the field of brain imaging, which can be used in a variety of areas, including helping motor activity, vision, hearing, and any damage that the body sustains. The BCI device records brain responses using invasive, semi-invasive and non-invasive methods including Electroencephalography (EEG), Magnetizhenophyllography (MEG), and Magnetic Resonance Imaging (MRI). Brain response using pattern recognition methods to control any translation application. In this article, a review of various techniques for extracting features and classification algorithms has been presented on brain data. A significant comparative analysis of existing BCI techniques is provided.",1,https://api.osf.io/v2/files/5d7b5e319defac001717a74c/,168,https://engrxiv.org/qg8er/,10.31224/osf.io/qg8er,,2019-09-13T14:05:58.530328,2019-09-13T14:06:22.639656 | |
| 4pgzn,"Achieving theoretical thermal conductivity and coeffieicent of thermal expansion in a W-Cu composite sheet","W-20wt.%Cu composite sheets with full density and good surface quality were successfully fabricated through an infiltration process followed by a hot rolling. After a total thickness reduction of 75%, the majority of the tungsten (W) particles have been deformed and elongated along the rolling direction. The aspect ratio of the W particles in the composite has reached 2.5. The relative density increases considerably to a maximum value of 99.8% when the rolling ratio increases. The thermal conductivity and microhardness of the W-Cu composites increase significantly with the rolling reduction. On the contrary, the coefficient of thermal expansion (CTE) of the composite samples decreases with the rolling ratio. Specifically, after subjected to 75% of thickness reduction, we obtained a large W-Cu thin sheet. This thin sheet demonstrates a low CTE of 7.27×10^-6/K and the highest thermal conductivity of 224.91 W/(m-K); both values are close to the respective theoretical ones.",1,https://api.osf.io/v2/files/5d78256af3535b0018e2a684/,78,https://engrxiv.org/4pgzn/,10.31224/osf.io/4pgzn,,2019-09-11T01:18:32.716016,2019-09-11T01:25:35.056797 | |
| hyzbx,"Identifying Sensitive Components in Infrastructure Networks via Critical Flows","This paper introduces a novel set of component importance measures that are based on the concept of critical flow. Various research communities have developed techniques for identifying critical components of networks. The methods in this paper extend previous work on flow-based centrality measures by incorporating insights from both critical infrastructure protection and urban planning. The motivation is to provide municipalities with a means of reasoning about the impact of urban interventions. An infrastructure system is represented as a flow network in which demand nodes are assigned both demand values and criticality ratings. Sensitive elements in the network are those that carry critical flows, where a flow is deemed critical to the extent that it satisfies critical demand. A method for computing these flows is presented, and its utility is demonstrated by comparing the new measures to existing flow centrality measures. The paper also shows how the method may be combined with a simple form of reliability analysis.",1,https://api.osf.io/v2/files/5d757d8834e7c20019407687/,171,https://engrxiv.org/hyzbx/,10.31224/osf.io/hyzbx,,2019-09-09T01:09:12.358712,2019-09-10T18:43:34.448212 | |
| sthzg,"Future Hydrogen Markets for Transport and Industry - The Impact of CO2 Taxes","The technological lock-in of the transportation and industrial sector can be largely attributed to the limited availability of alternative fuel infrastructures. Herein, a countrywide supply chain analysis of Germany, spanning until 2050, is applied to investigate promising infrastructure development pathways and associated hydrogen distribution costs for each analyzed hydrogen market. Analyzed supply chain pathways include seasonal storage to balance fluctuating renewable power generation with necessary purification, as well as trailer- and pipeline-based hydrogen delivery. The analysis encompasses green hydrogen feedstock in the chemical industry and fuel cell-based mobility applications, such as local buses, non-electrified regional trains, material handling vehicles, and trucks, as well as passenger cars. | |
| Our results indicate that the utilization of low-cost, long-term storage and improved refueling station utilization have the highest impact during the market introduction phase. We find that public transport and captive fleets offer a cost-efficient countrywide renewable hydrogen supply roll-out option. Furthermore, we show that, at comparable effective carbon tax resulting from the current energy tax rates in Germany, hydrogen is cost-competitive in the transportation sector by the year 2025. Furthermore, we show that sector-specific CO2 taxes are required to provide cost-competitive green hydrogen supply in both the transportation and industrial sectors.",1,https://api.osf.io/v2/files/5d724bae01a9f9001850d683/,126,https://engrxiv.org/sthzg/,10.31224/osf.io/sthzg,,2019-09-06T17:11:17.799526,2019-09-06T17:11:44.923775 | |
| vw89a,"Developing Low-Cost Inundation Maps for Dam Failures: Modeling and Analysis of a Potential Dam Failure for the Péligre Dam in Haiti","Dam failure relates to significant risk of human lives, property, and the environment protection. Understanding the risk that a dam introduces is significant for making contingency plans. After a dam failure an inundation map is a crucial component to understand the impact of flooding that will occur. This paper takes Péligre Dam in Haiti as the study area, using an innovative approach for producing inundation maps and estimate consequences. This research uses GIS and remote sensing techniques to merge DEM and generate land cover as data preprocessing, and subsequently uses the DSSWISE Lite System to develop the flood simulation and generate an inundation map for further estimation of life loss. It demonstrates the potential for the production of low-cost accurate inundation maps for dam failed emergencies that can be applied in other developing countries. As the result of the simulation with setting of a moderate breach of 100 meters that developed over 1 hour, it was estimated that 65 fatalities would occur and 202 buildings would be destroyed based on it.",1,https://api.osf.io/v2/files/5d71e0108bde94001862f1c2/,90,https://engrxiv.org/vw89a/,10.31224/osf.io/vw89a,,2019-09-08T18:25:54.117034,2019-09-08T18:26:08.342784 | |
| wxqg7,"Can a Water Smart Grid Help Society Achieve the Sustainable Development Goal of Water as a Human Right?","In the spirit of measuring what we care about, the UN Sustainable Development Goals (SDGs) provide guidelines to measure ``universal and equitable access to safe and affordable drinking water for all.'' In this work, I show where permanent or semi-permanent, autonomous or semi-autonomous technologies (objects, not processes) can measure and induce progress toward those goals and where they cannot. To do this, I apply the Institutional Analysis and Development Framework to each of the seven normative definitions from the SDGs as ``action arenas.'' For each normative definition, I examine if technologies exist or can be created to effect a positive outcome for consumers in that particular action arena using nine evaluative criteria. This analysis is applied to the United States as a case study considering its physical systems, regulations, and governance structures. This work, combined with efforts to translate the United States' systems and structures, can lead to multinational applicability. This paper examines how and when a water smart grid can and cannot be used effectively. I conclude that the material artifacts of a water smart grid can advance the SDG of safety and affordability. However, technology alone cannot assign people to jurisdictions, limiting its ability to advance goals of universal and equitable access.",1,https://api.osf.io/v2/files/5d7041f56f41fc001b37b237/,141,https://engrxiv.org/wxqg7/,10.31224/osf.io/wxqg7,,2019-09-05T20:00:49.981909,2019-09-05T20:01:03.159651 | |
| kc8wf,"Commercial microwave links for urban drainage modelling: The effect of link characteristics and their position on runoff simulations","Commercial microwave links (CMLs), radio connections widely used in telecommunication networks, can provide path-integrated quantitative precipitation estimates (QPEs) which could complement traditional precipitation observations. This paper assesses the ability of individual CMLs to provide relevant QPEs for urban rainfall-runoff simulations and specifically investigates the influence of CML characteristics and position on the predicted runoff. The analysis is based on a 3-year-long experimental data set from a small (1.3 km2) urban catchment located in Prague, Czech Republic. QPEs from real world CMLs are used as inputs for urban rainfall-runoff predictions and subsequent modelling performance is assessed by comparing simulated runoffs with measured stormwater discharges. The results show that model performance is related to both the sensitivity of CML to rainfall and CML position. The bias propagated into the runoff predictions is inversely proportional to CML path length. The effect of CML position is especially pronounced during heavy rainfalls, when QPEs from shorter CMLs, located within or close to catchment boundaries, better reproduce runoff dynamics than QPEs from longer CMLs extending far beyond the catchment boundaries. Interestingly, QPEs averaged from all available CMLs best reproduce the runoff temporal dynamics. Adjusting CML QPEs to three rain gauges located 2-3 km outside of the catchment substantially reduces the bias in CML QPEs. Unfortunately, this compromises the ability of the CML QPEs to reproduce runoff dynamics during heavy rainfalls. More experimental case studies are necessary to provide specific recommendations on CML preprocessing methods tailored to different water management tasks, catchments and CML networks.",1,https://api.osf.io/v2/files/5d6f6cf980f9b5001964387b/,212,https://engrxiv.org/kc8wf/,10.31224/osf.io/kc8wf,10.1016/j.jenvman.2019.109522,2019-09-04T13:38:29.492634,2019-09-23T10:01:32.710248 | |
| 5wz7d,"Correlation Transformational operators in Reactive Streams.","Abstract: | |
| This paper describes two operators, autocorrelation and with transformational A.I for an event and sensor streams in reactive object-oriented programming. | |
| The use of stream-beans and event-beans with multi-sensor integration with application in robotics is illustrated, with use in SLAM and other semantic transfer functions with cloud integration. | |
| Keywords: Correlation operators, transformational A.I, Reactive Programming, Correlation operators, EJBs, automated persistence, RxJava, RxJS | |
| What: | |
| Reactive Programming provides for the application of operators through iterators and the observer pattern on streams. In a previous paper (Bheemaiah 2019) we have extended automated persistence of java beans as EJBs to reactive programming, with the addition of event-beans and stream-beans, we now extend the iterator methods on these beans with cross-correlation and auto-correlation functions. | |
| We illustrate this with SLAM algorithms with correlation transformational A.I. We extend the SLAM algorithms to auditory localization. | |
| How: | |
| We define a transformational A.I based system of correlation algorithms for application to stream beans and event beans. | |
| We define its functionality in SLAM and in audio stream based localization of audio sources, both with or without echos. | |
| Why: | |
| Simultaneous localization and mapping can be achieved through both visual and auditory mechanisms. Localization is traditionally implied to mean the localization in absolute or relative coordinates with the creation of mapping and the additional determination of the pose of a camera for sensory input or a similar auditory localization as a pose in the case of lidar or ultrasound or audible range sound. Localization of sound sources is an extension of correlation-based SLAM algorithms.",1,https://api.osf.io/v2/files/5d6c1a0f80f9b5001962711f/,148,https://engrxiv.org/5wz7d/,10.31224/osf.io/5wz7d,,2019-09-02T14:54:01.983107,2019-09-02T14:54:22.474789 | |
| yhsbt,"Taskoids: A Formal Definition","Abstract: | |
| A formal definition of taskoids with a future market in trading in work credits with carbon credits and the happiness index clock. Taskoids are defined with a machine genome basis as the quantification of the automation of tasks. They stem from the natural programming, mathematical programming and automated persistence cloud model of computing with computer-assisted code generation. In this paper, we formally define a taskoid and use AWS infrastructure as a service to define IAC rules, encrypted in machine genome to customize solutions using AWS for tasks using a machine genome to transcript YAML or JSON representations. | |
| Keywords: Taskoids, Quantification, machine genome, cloud computing, YAML, JSON | |
| What: | |
| Formal Definition of Taskoids. | |
| The formal definition of machine genome. | |
| Definition and classification of task compatibility as the formulation of automation. | |
| Example of an AWS CloudWatch and CloudFormation based JSON based Taskoid. | |
| How: | |
| Taskoids are meta-programs that use existing codebases and automated coding to encrypt in machine genome a quantIfication of automation. | |
| Why: | |
| Similar to Soul Machines and Digital DNA of Digital Human designs, we create taskoids with machine genome to easily or automatically configure IAC to an application for a class of task computability.",1,https://api.osf.io/v2/files/5d68370e6f41fc001c2ecc3b/,118,https://engrxiv.org/yhsbt/,10.31224/osf.io/yhsbt,,2019-08-30T01:01:13.414906,2019-08-30T01:02:03.340259 | |
| 3ghkf,"Singularity#1 and MFA II. Singularität Nr. 1 und MFA II.","Abstract | |
| The Dog-Ears formal system (Bheemaiah, n.d.) is extended with MFA II architecture for the definition of Taskoids, needing adaptable designs and additive printing. We present a formal system to apply the formulation to illustrate Singularity#1 as an MFA II, application. The concept of Singularity and Singularity#1 and the MFA II design philosophy is explained, with an abstract photographic art. | |
| Keywords: Dog-Ears, Taskoids, Singularity, Singularity#1, Robotics, Conversational UI, additive printing. | |
| What: | |
| Singularity#1 is defined as an algorithmic machine evolution like genetic algorithms, in MFA II architecture, with the development of machine learning algorithms for the automated design of hardware and software and additive manufacturing of the hardware.MFA II is a multi-functional architecture, where side effects are primary too in a defined multi-functionality, it is inspired by MFA I architecture of form following function and behaviors from BEAM robotics, while BEAM is analog or mixed, MFA II is digital. | |
| Was: | |
| Singularity # 1 ist definiert als eine algorithmische Maschinenentwicklung wie genetische Algorithmen in der MFA II-Architektur mit der Entwicklung von Algorithmen für maschinelles Lernen für das automatisierte Design von Hardware und Software sowie für die additive Fertigung der Hardware. Es ähnelt der Singularität, die sich durch die Entwicklung von Hardware und Software für maschinelles Lernen durch A.I-Algorithmen auszeichnet. | |
| MFA II ist eine multifunktionale Architektur, bei der Nebenwirkungen auch bei einer definierten Multifunktionalität im Vordergrund stehen. Sie ist von der MFA I-Architektur mit Funktionen und Verhaltensweisen der BEAM-Robotik inspiriert, während BEAM analog oder gemischt und MFA II digital ist. | |
| How: | |
| We illustrate Singularity#1, in non-anthropomorphism in the design of Alexa skills and hardware tools for the sentient bot platform with additive manufacturing. Hardware extensions with the RetroSwitch are defined with a mathematical formulation, and templates with customization for the RetroSwitches and hardware designs are illustrated. | |
| TensorFlow is used for a mathematical formulation of MFA II with generalized Tensors. | |
| Wie: | |
| Wir veranschaulichen Singularität Nr. 1 im Nicht-Anthropomorphismus bei der Entwicklung von Alexa-Fertigkeiten und Hardware-Tools für die Plattform für empfindungsfähige Bots mit additiver Fertigung. Hardware-Erweiterungen mit dem RetroSwitch werden mit einer mathematischen Formulierung definiert, und Vorlagen mit Anpassungen für die RetroSwitches und Hardware-Designs werden veranschaulicht. | |
| TensorFlow wird für eine mathematische Formulierung von MFA II mit verallgemeinerten Tensoren mit eingebetteten Unendlichkeiten von Kovarianz und Kontravarianz und einer Konturintegralformulierung verwendet.",1,https://api.osf.io/v2/files/5d6835f26f41fc001a2e81f0/,87,https://engrxiv.org/3ghkf/,10.31224/osf.io/3ghkf,,2019-08-30T00:55:55.583746,2019-08-30T00:56:22.065668 | |
| t8fsr,"Modeling, Simulation and Control of a Robotic Arm","the precise control upon each degree of freedom of a robotic arm is a great challenge in implementing industrial work. To simplify mechatronics motion control systems design, this paper proposes mathematical modeling, simulation and control of a given electric motor in terms of input volt, Vin and output motions. The proposed model can be used to select, design, test and validate both plant's and motion control design to meet desired output performance. It presents a basic example of PID control applied to a robotic manipulator arm.",1,https://api.osf.io/v2/files/5d6815a472151000179b2ad5/,248,https://engrxiv.org/t8fsr/,10.31224/osf.io/t8fsr,,2019-08-30T00:52:10.627104,2019-08-30T00:52:22.960423 | |
| ckuh8,"Simulation of a Three link- Six Musculo Skeletal Arm Activated by Hill Muscle Model","The study of humanoid character is of great interest of researchers in the field of robotics and biomechanics. The one might want to know the forces and torques required to move a limb from an initial position to the desired destination position. Inverse dynamics is a helpful method to compute the force and torques for an articulated body limb. It enables us to know the joint torques required to rotate a link between two positions. Our goal in this study was to control a human-like articulated manipulator for a specific task of path tracking. For this purpose, the human arm was modeled with a three-link planar manipulator activated by Hill muscle model. Applying a proportional controller, values of force and torques applied to the joints were calculated by inverse dynamics and then joints and muscle forces trajectories were computed and presented. To be more accurate to say, the kinematics of the muscle-joint space was formulated by which we defined the relationship between the muscle lengths and the geometry of the links and joints. Secondary, the kinematic of the links was introduced to calculate the position of the end-effector in terms of the geometry. Then, we considered the modeling of Hill muscle dynamics and after calculation of joint torques, finally, we applied them to the dynamics of the three-link manipulator obtained from the inverse dynamics to calculate the joint states, find and control the location of manipulator’s end-effector. The results show that the human arm model was successfully controlled to take the designated path of an ellipse precisely.",1,https://api.osf.io/v2/files/5d67ef4072151000179b1513/,76,https://engrxiv.org/ckuh8/,10.31224/osf.io/ckuh8,,2019-08-29T15:59:18.891395,2019-08-29T18:39:02.394688 | |
| f4eq6,"Decentralized Routing Algorithm with Physical Time Windows for Modular Conveyors","We describe a decentralized routing algorithm with physical time windows for modular conveying systems. Existing routing algorithms for modular conveyors are already capable of bi-directional conveying while avoiding conflicts such as collisions, deadlocks, livelocks and starvation effects. In addition to avoiding conflicts, routing algorithms must also select routes that reduce the travel time. No existing algorithm for modular conveyors bases this decision on the expected physical lead time, even though physical lead time directly affects the system throughput. In this publication, we present an algorithm that uses the physical lead time to select routes while avoiding conflicts.",1,https://api.osf.io/v2/files/5d6502e08f8fe5001618a525/,144,https://engrxiv.org/f4eq6/,10.31224/osf.io/f4eq6,,2019-08-27T14:30:18.502308,2019-08-27T14:35:21.768070 | |
| 2q43z,"A CUDA-QUDA architecture, Hyperscale-Data Quantum GPUs","Abstract: | |
| QUDA is an architecture similar to CUDA for HPC applications of Quantum GPU architectures to be used in conjunction with GPU and MCU based processing. There is no QUDA pipeline similar to a stream processing architecture or an out of order instruction pipeline. True ILP is achieved with a QUDA architecture, which is better than quasi-parallelism in a CUDA or scalar/vector architecture. | |
| Keywords: QUDA architecture, HPC, Quantum Cloud, Qiskit, spin waves, spintronic, hyper-data, quantum operating system. | |
| What: | |
| Quantum Unified Compute Architecture or QUDA architectures is the use of Q and Qiskit for a reconfigurable quantum array architecture on spintronic units with a reconfigurable scheduler for a quantum operating system.",1,https://api.osf.io/v2/files/5d6442ff45dba20017eaddf0/,183,https://engrxiv.org/2q43z/,10.31224/osf.io/2q43z,,2019-08-26T22:29:23.100885,2019-08-26T22:29:44.297576 | |
| ctzue,"A RELATION BETWEEN LAMINATION PARAMETERS OF STIFFEST POST-BUCKLED COMPOSITE PLATE","The present paper deals with the anisotropic composite plates experiencing postbuckling. The plates have a symmetric lay-up and obey the geometrically non-linear von Karman law. A point-wise relation between the lamination parameters of the stiffest composite plates in postbuckling is derived and analyzed. It is shown that in the considered case not all lamination parameters are independent on each other (one of them is a linearly dependent one). The remaining linearly independent seven components of the lamination parameter vector are some non-linear functions of six parameters describing point-wisely the 2D principal strains and the principal curvatures. The analysis leads to a conclusion that the optimization w.r.t. the lamination parameters only is not sufficient for obtaining an optimal plate lay-up.",1,https://api.osf.io/v2/files/5d63f7798f8fe5001617a5d5/,167,https://engrxiv.org/ctzue/,10.31224/osf.io/ctzue,,2019-08-26T17:32:42.829029,2019-08-26T17:33:02.024976 | |
| 8nwfj,"Mapillary based plant distributions of ethnobotanical afforestation.","Abstract: | |
| Mapillary is an open-source code base for the use of GPU based Deep Learning for Semantic Segmentation of wild images. We propose the creation of an autonomous drone for the automated capture of scientific images of medicinal and edible plants to create geotagged maps of plants on Mapillary.com with additional tags on plant sizes, species, and edible and medicinal value. This information is used in the planning of sponsored five or more level afforestation as social and academic forestry for edible and medicinal value. The same research is also useful in planning afforestation on Mars. | |
| Keywords: Miyawakis, Mapillary, Seamless Segmentation, FPN, ResNet50, Redtail, Edible and Medicinal Plants, Geotag",1,https://api.osf.io/v2/files/5d5d6ece884b6600195c6953/,107,https://engrxiv.org/8nwfj/,10.31224/osf.io/8nwfj,,2019-08-22T12:16:30.333710,2019-08-22T12:17:23.514867 | |
| wq932,"Design of the Energy Storages for a (Battery) Electric Commuter Train","The use of battery-powered electric commuter trains instead of those which are propelled by internal combustion engines on only partially (or non) electrified railway lines can save considerable amounts of energy and can avoid exhaust emissions to a large extent with comparatively low investment costs. As path to these goals, the railway line, the operating and the trains are modeled for a particularly interesting, real-life example. Then, for the generated models, it is shown how the energy demands of model-compliant (battery) electric commuter trains can be calculated and how their energy storages can be designed. The models and the procedure can also be applied for a large number of comparable dimensioning cases when defining further railway lines, operating and commuter train models, corresponding parameterization as well as the occasionally necessary addition of slope and curvature resistances. The calculation of energy demands and the design of energy storages, however, show that there are a large number of different alternatives for technical specifications as well as decisions relevant to energy efficiency and business management, too. To determine the most suitable solutions, further measures such as the investigation of the effects of intelligent modifications to the underlying models, the development and implementation of computer-aided simulations as well as the construction and testing of real (battery) electric commuter trains make sense.",1,https://api.osf.io/v2/files/5d5a692f150734001cc971ec/,155,https://engrxiv.org/wq932/,10.31224/osf.io/wq932,,2019-08-19T13:45:22.464110,2019-08-19T13:45:43.723277 | |
| nw3d8,"Bus holding control of running buses in time windows","This work proposes a periodic bus holding control method where the bus holding times of all running trips are computed simultaneously within each optimization time period; thus, increasing the coordination among running buses to avoid bus bunching. We consider the adverse effects of the bus holding control on the in-vehicle travel times of on-board passengers and formulate holistic bus holding decisions by modeling the bus holding problem as a discrete, nonlinear, constrained optimization problem. Given the computational complexity of the bus holding problem, an alternating minimization approach is introduced for computing the optimal holding times at each optimization instance. The performance of the periodic control method is evaluated against the performance of event-based control methods using 5-month automated vehicle location and automated passenger count data from bus line 1 in Stockholm demonstrating an improvement potential of 5% for the in-vehicle travel times and 11% for the service regularity.",1,https://api.osf.io/v2/files/5d5917396e9c70001b00fe36/,188,https://engrxiv.org/nw3d8/,10.31224/osf.io/nw3d8,,2019-08-18T20:10:05.293874,2019-08-18T20:10:25.570716 | |
| swg4e,"One Green Quantum Computing Tablet Per Child","Abstract: | |
| A Paper on the design for the One Quantum Tablet Per Child, the new E-Paper in Graphene and organic polymer on PLA substrate, with a Quantum Ising Glass architecture with spin wave based STT, Quantum Internet for last mile connectivity and a distributed QPU-GPU-MCU architecture for robust scalable fault tolerant computing. | |
| Keywords: Graphene, OLED, MCU-QPU-GPU, integration, E-Paper, Quantum Cloud, Quantum Operating systems, E-Learning, Quantum Tablet, Mathematical Truth, Light as New Age Religion.",1,https://api.osf.io/v2/files/5d55ba3d6e9c70001afe104b/,180,https://engrxiv.org/swg4e/,10.31224/osf.io/swg4e,,2019-08-15T21:32:27.796969,2019-08-15T21:32:44.107087 | |
| 2ybpq,"Computational Intelligence in Conversational UI, A BotLibre Case Study. A survey paper","This publication is on the computational | |
| intelligence of Chat conversational UIs | |
| that spans from, NLP, RPA, DNN’s , | |
| emergent computing to other paradigms | |
| of A.I which also include rule based | |
| systems and heuristic definition | |
| languages(HDL). The design of the | |
| BotLibre conversational UIs is presented | |
| as a case study, including future work in | |
| improving the knowledge management | |
| and database use, from postgre SQL to | |
| NoSQL and more sophisticated database | |
| clusters. | |
| Keywords: conversational UI, botlibre, | |
| NLP, Deep Learning, RPA.",1,https://api.osf.io/v2/files/5d5585ebffde5b0017ff0b86/,228,https://engrxiv.org/2ybpq/,10.31224/osf.io/2ybpq,,2019-08-15T21:31:38.309084,2019-08-15T21:32:03.076173 | |
| d3t8x,"Personality In Conversational UI design.","This paper describes mathematical representations for personality as an emergence, in the design | |
| of conversational UI, from voice, video and image. We use SoulMachines conversational UI as a case | |
| study, for the determination of data structures for personality definition. This model differs from | |
| other models in the existence of several aspects of personalities, with the possibility of the stability | |
| of one or more atomic aspects of a personality. Thus naturalness exists for the definition of a | |
| personality",1,https://api.osf.io/v2/files/5d546074c3f52f001cff4de7/,123,https://engrxiv.org/d3t8x/,10.31224/osf.io/d3t8x,,2019-08-15T14:12:00.067940,2019-08-15T14:12:25.726150 | |
| chtsa,"Consonant voicing and devoicing","In this project, we investigate consonant voicing and devoicing problems and claim that several acoustic parameters are effective.",1,https://api.osf.io/v2/files/5d53845bc3f52f0019ff8af5/,102,https://engrxiv.org/chtsa/,10.31224/osf.io/chtsa,,2019-08-15T14:09:44.603448,2019-08-15T14:10:26.609153 | |
| gkfp9,"AN EMPIRICAL STUDY LINKING ADDITIVE MANUFACTURING DESIGN PROCESS TO SUCCESS IN MANUFACTURABILITY","This paper characterizes engineering designers’ abilities to re-design a component for additive manufacturing, employing screen capture methods. Additive Manufacturing has garnered significant interest from a wide range of industries, academia and government stakeholders due to its potential to reform and disrupt traditional manufacturing processes. The technology offers unprecedented design freedom and customization along with its ability to process novel and high | |
| strength alloys in promising lead times. To harness the maximum potential of this technology, designers are often tasked with creating new products or re-design existing portfolios of traditionally manufactured parts to achieve lightweight designs with better performance. To date, few studies explore the correspondence between design behaviors and manufacturability of final product within an Additive Manufacturing context. This paper presents empirical data from the design processes of six graduate student engineering designers as they re-design a traditionally designed part for additive manufacturing. We compare behaviors through the design task between the study participants with a quantitative measure of the manufacturability and quality of each design. Results indicate opportunities for further research and best practices in design for Additive manufacturing and engineering education practitioners across multiple disciplines.",1,https://api.osf.io/v2/files/5d51c5d3e35fc6001956938d/,222,https://engrxiv.org/gkfp9/,10.31224/osf.io/gkfp9,,2019-08-13T17:06:44.777699,2019-08-13T17:07:06.857066 | |
| 2mtfu,"Critical Buckling Load of Thin-Walled Plastic Cylinders in Axial and Radial Loading: Overview and FEA Case Study","This technical note discusses the theoretical static buckling load of thin-walled plastic cylinders under axial and radial loading. While the buckling of thin-walled cylinders is a well-researched topic, a variety of new design and manufacturing methods, as well as advances in polymer technologies, have brought plastic structures into prominence in recent years, necessitating a re-examination and exploration of their behavior under buckling loads. This work provides a background review of the problem, a discussion of the appropriate buckling equations, an extensive case study to demonstrate the concepts, and a brief review of some previously developed thin-walled structure reinforcement techniques. The presented work and results are intended to provide a helpful perspective, background review, and starting place for future research on the buckling behavior of thin plastic structures.",1,https://api.osf.io/v2/files/5d5165ddfd9dd70016e16580/,262,https://engrxiv.org/2mtfu/,10.31224/osf.io/2mtfu,,2019-08-12T15:17:20.053378,2019-08-12T15:17:43.032955 | |
| xz2ek,"Lean A.I and Automation","Lean A.I is a data mining algorithm that implements the Referendum Algorithms for polls and blog | |
| data lakes, to implement the Lean process in an organization. This paper discusses the Referendum | |
| Algorithms and its application to the automated implementation of Lean methodology.",1,https://api.osf.io/v2/files/5d4d99310f488d0018918e2a/,109,https://engrxiv.org/xz2ek/,10.31224/osf.io/xz2ek,,2019-08-09T16:44:32.186590,2019-08-09T16:49:10.245774 | |
| zry7h,"DSMC Simulation of Rarefied Gas Flow in a Single-sided and Double-sided Lid-Driven Cavity","The present study is to investigate the behavior of a monoatomic gas enclosed in a cavity with both the top and bottom walls imparting motion to the fluid. The problem is studied for single and double-sided lid-driven flow for various wall velocities as well as parallel and anti-parallel wall motions. These types of flow have many industrial applications such as drying and melt spinning. In contrast to the single-sided flows the vortex patterns obtained in the double-sided flows are different and hence it merits a thorough examination, which is studied in this paper using the Direct Simulation Monte Carlo (DSMC) method. The DSMC method proposed by G.A. Bird is based on the kinetic theory in which the molecular motion is modeled stochastically. The computational model has been implemented in OpenFOAM software using the solver named dsmcFoam. Various flow features have been examined such as eddies and vortices.",1,https://api.osf.io/v2/files/5d4cf9a122a88600184f5586/,195,https://engrxiv.org/zry7h/,10.31224/osf.io/zry7h,,2019-08-09T16:41:31.355891,2019-08-09T16:41:44.195602 | |
| w3tnr,"Consonant Voicing Investigation","Obstruct consonant could be detected by energy difference profiles. In thisproject, we investigate algorithm to detect three types of landmarks, [stopclosure], [stop release], [fricative closure]. As a result, Overall detection ratesfor stop closure and release are 71.3% and 82.3% for obstruent landmarks inTIMIT, and fricatives yield 83.2% and 81.9% respectively.",1,https://api.osf.io/v2/files/5d4c372f272b140018ec7518/,214,https://engrxiv.org/w3tnr/,10.31224/osf.io/w3tnr,,2019-08-09T16:39:53.440574,2019-08-09T16:40:06.567957 | |
| 4x9g8,"A Power and Area Efficient CMOS Bandgap Reference Circuit with an Integrated Voltage-Reference Branch","This work presents a compact and low power bandgap voltage reference design using self-biased current mirror circuit. This design eliminates the standard complementary-to-absolute-temperature (CTAT) bipolar device in the voltage-reference branch, reducing the bipolar area by 20 percent. Instead, the design shares the same bipolar device in the main CTAT branch for generating the reference voltage. An additional benefit of eliminating the voltage-reference branch is the reduction of total power consumption by approximately 30 percent. This novel topology reduces power and area of the core bandgap reference circuit without compromising temperature drift performance. Designed, fabricated and functionally tested in a 0.6 um CMOS process. The simulation result shows the temperature coefficient of this design is 6.3 ppm/C for a temperature range of -40C to 125C$. This bandgap reference design occupies a silicon area of 0.018 mm^2 and draws an average quiescent current of 2 uA from a supply voltage of 3.3-5V. The simulated flicker voltage noise is 4.34 uV/sqrt-Hz at 10 Hz.",1,https://api.osf.io/v2/files/5d4c0da7272b140018ec5139/,268,https://engrxiv.org/4x9g8/,10.31224/osf.io/4x9g8,,2019-08-08T14:11:11.999989,2019-08-09T13:00:01.205229 | |
| wnfxp,"Neural Machine Translation with FastMoS","In recent years, machine translation make great progress especially in neural machine translation | |
| \cite{Wu:2016:arXiv,luong2015effective,gehring2017convolutional,sutskever2014sequence,tu2016modeling,bahdanau2014neural,kong2019neural}. In \citep{kong2019fast}, they use a fast mos to obtain great performance on some machine translation corpora. In this project, we investigate this method to improve the performance of other machine translation corpora.",1,https://api.osf.io/v2/files/5d4b9c4c22a88600164f7b90/,85,https://engrxiv.org/wnfxp/,10.31224/osf.io/wnfxp,,2019-08-08T14:09:03.084559,2019-08-08T14:09:27.877765 | |
| 4z3vk,"PHYSICAL AND RHEOLOGICAL PROPERTIES OF HYPER MODIFIED BITUMENS BY SBS","The asphalt is the important component to link the mineral materials of the road, the asphalt as a viscoelastic material, their mechanical and thermal characteristics insufficient for our region (Southern Algeria), the traditional asphalt which used in Algeria is hard but has his short life, For this reason impose Algeria and other country in the last year to improve the traditional materials of pavement concrete, by adding the polymers that allow to reduce the sensitivity part to temperature and viscous, and increases its flexibility and rigidity. | |
| In this study, we modified the asphalt by 5% we called standard modified bitumen and 7.5% noted as the hyper modified bitumen, in this modification we used an SBS, and follow the influence of polymer on asphalt viscosity, their mechanical and rheological characters changes using DMA test. also other tests carried out showed that adding of 7.5% by SBS, increase the rigidity, elasticity and reduce thermal susceptibility, in addition can predict the behavior of asphalt on the road.",1,https://api.osf.io/v2/files/5d4acb5922a88600164eaabe/,164,https://engrxiv.org/4z3vk/,10.31224/osf.io/4z3vk,,2019-08-07T20:50:37.596957,2019-08-07T20:51:02.963469 | |
| c7hsj,"Perfusion 3D Bioprinting with Gelatin and Hydrogel for Vascular Tissue Engineering","Vascular disease is one of the leading causes of morbidity and mortality in developed countries, and thereby necessitates the replacement of diseased artery or vein through surgical intervention. Tissue engineering offers an alternative approach of designing biomaterials for small diameter artery regeneration. | |
| Vascular graft infections occur infrequently, with an incidence that varies by surgical site but in general ranges from 0.5% to 6%. Infections of vascular grafts are associated with significant mortality and morbidity risk. Vascularization is also a major problem in tissue engineering, especially for engineering tissues that are thicker than approximately 200 μm. Insufficient vascularization limits the oxygen and nutrient transfer to cells, which can lead to hypoxia and formation of non-uniform tissue structures. Vasculature-like structures are usually multilayer and hollow. They have a complex shape with varying diameters throughout the body. Thus, it is quite difficult to imitate this complex 3D structure using materials similar to native vessels such as hydrogels. Though a few techniques have been explored to fabricate this complex 3D structure, direct bioprinting of such a complex 3D structure on a solid platform in a single step has not been realized. | |
| Natural vascular tissues serve as a unique experimental tool for investigating fundamental mechanisms of vascular function and maturation process under 3D flow conditions. The methods have great potential in vascularized tissue fabrication as the vascular channel is simultaneously created while cells and matrix are printed around the channel in desired 3D patterns",1,https://api.osf.io/v2/files/5d4a7edb265be2001a2cf136/,242,https://engrxiv.org/c7hsj/,10.31224/osf.io/c7hsj,,2019-08-07T20:49:20.966090,2019-08-07T20:49:41.949781 | |
| 3dh9s,"Build Orientation Optimization for Strength Enhancement of FDM Parts Using Machine Learning based Algorithm","The layered fabrication approach induces directional anisotropy and impacts mechanical strength of FDM components significantly. This paper proposes generalized machine learning based parameter optimization framework to determine optimal build orientation for FDM components. The algorithm determines ideal build orientation by maximizing the minimum Factor of Safety (FoS) for the component under prescribed loading conditions ensuring its even distribution. An Artificial Neural Network (ANN) coupled with Bayesian algorithm has been employed to accelerate the optimization process. The algorithm begins with an initial sample data collected using brute force approach; uses single layered ANN for approximation and optimization is achieved using Bayesian algorithm. A series of computational experiments considering five different test components has been devised to evaluate the performance and efficacy of the proposed algorithm. These experiments demonstrated that the proposed algorithm can determine the optimum building orientation effectively with certain limitations",1,https://api.osf.io/v2/files/5d486051bcd6d900178fd582/,261,https://engrxiv.org/3dh9s/,10.31224/osf.io/3dh9s,10.14733/cadaps.2020.783-796,2019-08-06T15:38:44.253632,2019-11-06T20:21:30.486214 | |
| hsjme,"Modeling Hydrogen Networks for Future Energy Systems: A Comparison of Linear and Nonlinear Approaches","Common energy system models that integrate hydrogen transport in pipelines typically simplify fluid flow models and reduce the network size in order to achieve solutions quickly. This contribution analyzes two different types of pipeline network topologies (namely, star and tree networks) and two different fluid flow models (linear and nonlinear) for a given hydrogen capacity scenario of electrical reconversion in Germany to analyze the impact of these simplifications. For each network topology, robust demand and supply scenarios are generated. The results show that a simplified topology, as well as the consideration of detailed fluid flow, could heavily influence the total pipeline investment costs. For the given capacity scenario, an overall cost reduction of the pipeline costs of 37% is observed for the star network with linear cost compared to the tree network with nonlinear fluid flow. The impact of these improvements regarding the total electricity reconversion costs has led to a cost reduction of 1.4%, which is fairly small. Therefore, the integration of nonlinearities into energy system optimization models is not recommended due to their high computational burden. However, the applied method for generating robust demand and supply scenarios improved the credibility and robustness of the network topology, while the simplified fluid flow consideration can lead to infeasibilities. Thus, we suggest the utilization of the nonlinear model for post-processing to prove the feasibility of the results and strengthen their credibility, while retaining the computational performance of linear modeling.",1,https://api.osf.io/v2/files/5d48412b90489f00194a3a35/,286,https://engrxiv.org/hsjme/,10.31224/osf.io/hsjme,,2019-08-06T15:41:02.936923,2019-08-06T15:41:21.985758 | |
| aebn7,"Evolutionary computing in neuronal modeling","The efficacy of genetic algorithms in the design of models that model specific and experimental aspects | |
| of action potentials in a wide variety of organisms is proven. A specific example of a plant action | |
| potential is used to illustrate the use of genetic algorithms in the search for parameters of models. The | |
| efficiency of the genetic algorithms as a search method is in the short generation span of the | |
| convergence of the algorithm.",1,https://api.osf.io/v2/files/5d473ff5bcd6d900188f0d31/,178,https://engrxiv.org/aebn7/,10.31224/osf.io/aebn7,,2019-08-04T21:57:48.162418,2019-08-04T21:58:07.429926 | |
| ycnge,"Central vs Decentralized motion control in worm robots.","This paper describes two robotic solutions WAV and CMMWorm that illustrate a distributed and a centralized motion control and mechanism. Both approaches are shown to be equivalent but nature is inherently of a fault tolerant distributed nature while man made designs are centralized for ease of manufacturing. They are also inherently fault tolerant in the need for the replacement of only one control and propulsion mechanism.",1,https://api.osf.io/v2/files/5d473d7490489f001c49d949/,189,https://engrxiv.org/ycnge/,10.31224/osf.io/ycnge,,2019-08-04T21:55:06.935930,2019-08-04T21:55:24.361977 | |
| urxgs,"Updating Maxwell with Electrons and Charge Aug 2-1.pdf (Version: 1)","Maxwell's equations describe the relation of charge and electric force almost perfectly even though electrons and permanent charge were not in his equations, as he wrote them. For Maxwell, all charge depended on the electric field. Charge was induced and polarization was described by a single dielectric constant. Electrons, permanent charge, and polarization are important when matter is involved. Polarization of matter cannot be described by a single dielectric constant ?_(r )with reasonable realism today when applications involve 10^(-10) sec. Only vacuum is well described by a single dielectric constant ?_(0 ). | |
| Here, Maxwell's equations are rewritten to include permanent charge and any type of polarization. Rewriting is in one sense petty, and in another sense profound, in either case presumptuous. Either petty or profound, rewriting confirms the legitimacy of electrodynamics that includes permanent charge and realistic polarization. One cannot be sure ahead of time that a theory of electrodynamics without electrons or (permanent, field independent) charge (like Maxwell's equations as he wrote them) would be legitimate or not. After all a theory cannot calculate the fields produced by charges (for example electrons) that are not in the theory at all! | |
| After updating, | |
| Maxwell's equations seem universal and exact. | |
| Polarization must be described explicitly to use Maxwell's equations in applications. | |
| Conservation of total current (including ?_0 ?E??t) becomes exact, independent of matter, allowing precise definition of electromotive force EMF in circuits. | |
| Kirchhoff's current law becomes as exact as Maxwell's equations themselves. | |
| Classical chemical kinetics is seen to need revision to conserve current.",1,https://api.osf.io/v2/files/5d4594cb90489f001b4b6e58/,138,https://engrxiv.org/urxgs/,10.31224/osf.io/urxgs,,2019-08-03T19:38:06.507338,2019-08-29T15:56:46.314780 | |
| 2739d,"PNP what is in a name july 25-1 2019.pdf 10.31224/osf.io/2739d","The name PNP was introduced by Eisenberg and Chen because it has important physical meaning beyond being the first letters of Poisson-Nernst-Planck. PNP also means Positive-Negative-Positive, the signs of majority current carriers in different regions of a PNP bipolar transistor. PNP transistors are two diodes in series PN + NP that rectify by changing the shape of the electric field. Transistors can function as quite different types of nonlinear devices by changing the shape of the electric field. Those realities motivated Eisenberg and Chen to introduce the name PNP. | |
| The pun “PNP = Poisson-Nernst-Planck = Positive-Negative-Positive” has physical content. It suggests that Poisson-Nernst-Planck systems like open ionic channels should not be assumed to have constant electric fields. The electric field should be studied and computed because its change of shape is likely to be important in the function of biological systems, as it is in semiconductor systems.",1,https://api.osf.io/v2/files/5d4593e8bcd6d90016916be1/,143,https://engrxiv.org/2739d/,10.31224/osf.io/2739d,,2019-08-03T19:38:51.796885,2019-08-15T12:41:15.784424 | |
| r73k5,"Investigation of the IGT25 Turbo-Compressor Control Logic Behavior Coupling with a 25-MW Consumer under Dynamic Loading","Implementing control logic in dynamic modeling of gas turbines is one of the important and effective methods in analyzing the performance of IGT25 gas turbine; because, in dynamic modeling, various results would be achieved, through different control philosophies. To do so, using behavioral analysis of the performance of IGT25 gas turbine under different ambient conditions and different fuel compositions, appropriate control logic could be extracted. In the paper, method of extraction and entering the control logic in modeling dynamic condition of IGT25 gas turbine coupled with a 25MW consumer has been studied under different ambient conditions such as various ambient temperature and pressure, relative humidity, and fuel compositions. Primarily, various scenarios existing in relation to gas turbine control have been studied; then, studying the dynamic behavior of IGT25 gas turbine under the aforementioned condition, considered control logic has been reviewed. Data obtained are at the nominal load and the condition in which the turbine’s temperature controller has been set to higher temperatures so that the maximum output load is achieved for the consumer.",1,https://api.osf.io/v2/files/5d44e66d3ce9350019ededd4/,205,https://engrxiv.org/r73k5/,10.31224/osf.io/r73k5,,2019-08-03T19:28:40.788033,2019-08-03T19:29:04.499134 | |
| 5xust,"Adsorption of methyl blue with activated carbon derived from peanut shell","In this study we synthesized activated carbon (AC) sourced from peanut shell, an agricultural waste, for the adsorption of methyl blue from its aqueous solution. AC was produced via chemical activation method and was characterized using various tools like XRD, FESEM and Raman spectroscopy. Adsorption experiments were carried in different batches with varying initial concentration, adsorbent dose, contact time, pH and temperature. The optimized parameters for adsorption were found to be that of initial dye concentration of 150 mg/L, adsorbent dose of 120 mg/L, temperature equals to 50C, contact time of 50 minutes and pH equals to 8. Adsorption data were used to figure out isotherm models, kinetics as well as thermodynamics of the process. It was concluded that maximum adsorption capacity is coming to be 714.28 mg/g, and the adsorption is favoring the Tempkin isotherm model. Also it was observed that the process is endothermic and spontaneous in nature.",1,https://api.osf.io/v2/files/5d43af083ce9350019ed4cef/,196,https://engrxiv.org/5xust/,10.31224/osf.io/5xust,,2019-08-02T13:00:16.191401,2019-08-02T13:00:44.624415 | |
| gckxb,"Investigating of Turbine Blades Geometrical Change Effects on Dynamic Performance of IGT-25 Gas Turbine","In the paper, the effect of gas generator turbine blades’ geometrical change has been studied on the overall performance of a twin-shaft 25MW gas turbine with industrial application, under dynamic conditions. Geometrical changes include change of thickness and height of gas generator turbine blades which in turn would result in the change in the mass flow rate of passing hot gas, as well as isentropic efficiency in each stage of the turbine. Gas turbine modeling in the paper is zero-dimensional and takes place with consideration of dynamic effects of volume on air compressor components, combustion chamber, gas generator turbine, power turbine, fuel system, as well as effects of heat transfer dynamics between blades, gas path, and effects of operators on inlet guide vanes, fuel valves, and air compressor discharge valve. In the mathematical model of each of the components, steady-state characteristics curves have been used, extracted from 3-Dimensional computational fluid dynamics (CFD). To do so, characteristic curves of the first and second stages of the four-stage turbine have been updated through 3-D fluid dynamic analysis so that the effect of geometrical changes in turbine blades would be applied. Results from effects of these changes on characteristics of transient gas flow including output power of gas generator turbine and power turbine, inlet and outlet temperatures of turbine stages, as well as air and fuel mass flow rates have been provided from the start-ups until reaching the nominal load would be achieved.",1,https://api.osf.io/v2/files/5d4395c33ce9350018eeaf17/,218,https://engrxiv.org/gckxb/,10.31224/osf.io/gckxb,,2019-08-02T12:57:40.478257,2019-08-02T12:58:02.883474 | |
| thfwr,"Graphene Quantum Dots for Quantum GPU architectures.","This paper is on a quantum architecture using the Display Computing paradigm, for a Quantum GPU design. It builds on my previous work on quantum reconfigurable computing. The design builds on a generalized 10 qubit architecture that can be reconfigured to provide display stream and input stream transformation using quantum computing.",1,https://api.osf.io/v2/files/5d40ae593ce9350018ec01e5/,200,https://engrxiv.org/thfwr/,10.31224/osf.io/thfwr,,2019-08-02T12:54:43.361595,2019-08-02T12:55:04.795836 | |
| 2h3d6,"Display Computing - Design of monocular Auto Pilot systems","Display Computing is a new paradigm of GPU computing, where each image is computed from the previous images using generalized transformation theory. This is applied to monocular video for procedural and emergent A.I to create an autopilot for drones and robots. A microphone with the same A.I applied to audio infrasonic streams can supplement the autopilot system. This paper describes the mathematical models and algorithm",1,https://api.osf.io/v2/files/5d4095f490489f001c469143/,158,https://engrxiv.org/2h3d6/,10.31224/osf.io/2h3d6,,2019-08-02T12:53:17.035759,2019-08-02T12:53:45.177341 | |
| m3hp4,"Application of Soret Effect in Optimum Desalination Process","The ocean makes up 70 percent of the earth’s surface and accounts for 96 percent of the water on the planet. Unfortunately this water cannott be consumed. It is s oversaturated with salt. Desalination is the process of turning salty ocean water into drinking water. With 783 million people lacking access to clean water and more areas facing severe droughts, desalination can be the answer of this problem. But like other ajor industrial processes, desalination has environental impacts that must be understood and mitigated. The effects on the marine environment associated with the construction and long-term operation of seawater desalination plants, including withdrawing water from the ocean and discharging the highly concentrated brine. With that disadvantages a more optimum and environmentally responsible mechanism is needed to supply clean water.",1,https://api.osf.io/v2/files/5d40012626ebf50019843821/,217,https://engrxiv.org/m3hp4/,10.31224/osf.io/m3hp4,,2019-07-30T17:57:02.927323,2019-07-30T17:57:21.826616 | |
| j87bk,"Application of Polydopamine Doped Gel Electrolyte to Improve Lithium-Ion Battery Performance","The rapidly and globally increasing demand for energy results in challenges concerning not only the conversion but also the storage of electrical energy. The currently most common battery systems are based on the Li-ion technology. This technology was proposed by M. S. Whittingham in 1976, commercialized by SONY in 1990, and represents the best investigated and, due to its uniquely high-power density, most popular battery system today. However, for applications related to the Internet of Things (IoT), such as aRFID tags, sensors, smart clothes, or smart packaging, and flexible Organic Light emitting diode (OLED) the Li-ion technology reaches its limits. The demands for such thin-film applications clearly differ from conventional batteries (e.g., consumer electronics or electromobility). Vital requirements are flexibility, absence of toxic and harmful metals, the production from abundant and, ideally, renewable resources, rapid charging, excellent cycle life, and efficient processing using roll-to-roll or similar processing techniques",1,https://api.osf.io/v2/files/5d3ff17090489f001c4616d1/,239,https://engrxiv.org/j87bk/,10.31224/osf.io/j87bk,,2019-07-30T17:56:16.763993,2019-07-30T17:56:41.626407 | |
| yw6d9,"The universality of the Conversational UI Interface with media in UX design","This publication proves the equivalence of an animated or non-animated conversational UI with Html 5 canvas to any UX design. The universality of the interactive voice interface is proven by the enumeration of the UX widgets and the proof of equivalence to interactive voice response with visual display. | |
| What: The proof of the equivalence of conversational UI with or without media to a visual interface based on mouse or keyboard or other interactions. | |
| How: An enumeration of widgets and other UI and equivalence in the conversion to conversational UI with media. | |
| Why: Accessibility is natural in conversational UI, necessitating the conversion and equivalence. Conversational UI is hands-free and natural.",1,https://api.osf.io/v2/files/5d3f5288596eee001d6515c4/,207,https://engrxiv.org/yw6d9/,10.31224/osf.io/yw6d9,,2019-07-30T17:53:31.140164,2019-07-30T17:53:46.238533 | |
| k4fxm,"EFFECT OF SURFACE ROUGHNESS ON STEADY PERFORMANCE OF HYDROSTATIC THRUST BEARINGS: RABINOWITSCH FLUID MODEL","Purpose of the present theoretical investigation is to analyze the effects of surface roughness on the steady-state performance of stepped circular hydrostatic thrust bearings lubricated with non-Newtonian Rabinowitsch type fluids. Results for film pressure and load-carrying capacity have been plotted and analyzed on the basis of numerical results. To take the effects of surface roughness into account, Christensen theory of rough surface has been adopted. The expression for pressure gradient has been derived by means of the energy integral approach. This approach avoids the derivation of Reynolds’ equation. The numerical results for film pressure and load capacity have been obtained using Mathematica. It was observed that in comparison with smooth surfaces, dimensionless film pressure and load capacity is lower for longitudinal roughness and higher for circular roughness patterns with and the variations are significant. Load carrying capacity decreases with the increase of longitudinal roughness and, increases with the increase of circular roughness. Further, the effects of surface roughness and non-Newtonian lubricants are significant for larger values of inertia parameter. Because of the closeness of results to the experimental values, this study will be helpful in the design of circular hydrostatic thrust bearings.",1,https://api.osf.io/v2/files/5d3c38e0596eee001e62991c/,229,https://engrxiv.org/k4fxm/,10.31224/osf.io/k4fxm,,2019-07-27T23:27:31.913613,2019-07-27T23:27:47.016901 | |
| a8d3x,"Enterprise Java Beans with ReactiveX.","Abstract: | |
| This publication is on the automation of persistence, with the example of a Legacy solution, in the form of Enterprise Java Beans. While Java EE and EJB’s are depreciated. They are bridged to the present models of SaaS and serverless computing, through the introduction of two new stateful beans, StreamBean and EventBean, for functional, reactive and Cloud based automated persistence with the ability to implement any design pattern template with the Bean. | |
| This paper is on the transition from imperative programming in SQL to a NoSQL based serverless design with automation of the persistence layer in the cloud.",1,https://api.osf.io/v2/files/5d3b4d7e6a1e6f001ad57724/,227,https://engrxiv.org/a8d3x/,10.31224/osf.io/a8d3x,,2019-07-27T23:11:30.501819,2019-07-27T23:11:46.673807 | |
| 7zdu3,"Formal Methods for Multi Modal UI for Robotics","A formal system of mathematics the dog-ears, is introduced to describe javascript or object notation, sensor event and action event with state modelling in the framework of DPA for a smart home and work robotics . It is assumed that a multi modal interface can be developed similar to AWS APL for this purpose. | |
| The RAVA natural programming language is introduced, which simplifies coding by eliminating the need for syntax.",1,https://api.osf.io/v2/files/5d3b4b0e6a1e6f001ad57527/,210,https://engrxiv.org/7zdu3/,10.31224/osf.io/7zdu3,,2019-07-27T23:08:07.527484,2019-07-27T23:08:22.007524 | |
| t3d86,"High-Resolution One-Dimensional Modeling of a Gas Turbine Combustor Using Eulerian-Lagrangian Method","In this paper, a dynamic combustor model for inclusion into a one-dimensional full gas turbine engine simulation model, with high numerical accuracy is developed. Effects of dominant parameters, such as frequency and amplitude of the inlet air and fuel mass flow rate fluctuations, on outlet temperature of the combustion chamber, are investigated. The main goal of this research is to analyze the response of the gas turbine combustor to dynamic events that occur in the compressor. In the present work, for modeling combustion, the equations of chemical equilibrium (a second-law concept) are developed and applied to combustion-product mixtures. Thus the heat released from combustion is computed and used as a source term in the energy equation. Ignition effects either would be considered with a time lag equation as a source term in the energy equation. The combustor flammability limits are determined by using available experimental data for various gases and also Le Chatelier’s law. Source terms of governing equations are added using the operator splitting method. To operate this, the modified version of the PPM algorithm called PPMLR is used which solves the Euler equations in Lagrangian coordinates. At the end of each time step, results calculated in the Lagrangian coordinates would remap to the original Eulerian coordinate. The results revealed that to achieve a grid-independent solution, the accuracy of 0.002 m over the length of the combustion chamber should be applied. By reducing the accuracy of simulation, numerical diffusion causes a rise in flow temperature along with the combustion chamber. Through the dynamic modeling aspect, it is found that by increasing inlet fuel flow rate frequency up to 25 Hz, the amplitude of the fluctuations of outlet temperature, increases. Further increase in frequency up to 100 Hz, the amplitude of the fluctuations remains unchanged. However further increases in frequency from 100 Hz, causes amplitudes of outlet temperature fluctuations to decrease.",1,https://api.osf.io/v2/files/5d3a965ea3c0020018854de1/,192,https://engrxiv.org/t3d86/,10.31224/osf.io/t3d86,,2019-07-27T23:04:30.687765,2019-07-27T23:04:45.359561 | |
| k937j,"Investigation of Influencing Parameters and Determination of the Lower and Upper Limits of Flammability of a 25MW Industrial Gas Turbine Combustor","In the paper, combustion flammability limits in the combustion chamber of gas turbines and effective factors on these limits would be studied. Considering flammability, initiation of combustion and stability limit are very important parameters in the performance of the gas turbine combustion chamber and to study these factors, flammability of combustion has to be controlled. So, in the paper, the method of calculation of these limits and factors having effects on them would be studied. Also, some of the theoretical models would be reviewed, in which flammability limits would be estimated through experimental data. Finally, with consideration of the aforementioned relations, an optimal method for calculation of upper and lower flammability limits in the gas turbine combustion chamber would be presented.",1,https://api.osf.io/v2/files/5d394fa0eb4caa0017996921/,291,https://engrxiv.org/k937j/,10.31224/osf.io/k937j,,2019-07-25T19:09:25.531933,2019-07-25T19:09:43.617340 | |
| b7gk6,"A Hybrid Model to Predict the Gyratory Compaction of Hot Mixed Asphalt","The compaction of asphalt mixture is crucial to the mechanical properties and the maintenance of the pavement. However, the mix design, which based on the compaction properties, remains largely on empirical data. We found difficulties to relate the aggregate size distribution and the asphalt binder properties to the compaction behavior in both the field and laboratory compaction of asphalt mixtures. In this paper, we would like to propose a simple hybrid model to predict the compaction of asphalt mixtures. In this model, we divided the compaction process into two mechanisms: (i) visco-plastic deformation of an ordered thickly-coated granular assembly, and (ii) the transition from an ordered system to a disordered system due to particle rearrangement. This model could take into account both the viscous properties of the asphalt binder and grain size distributions of the aggregates. Additionally, we suggest to use the discrete element method to understand the particle rearrangement during the compaction process. This model is calibrated based on the SuperPave gyratory compaction tests in the pavement lab. In the end, we compared the model results to experimental data to show that this model prediction had a good agreement with the experiments, thus, had great potentials to be implemented to improve the design of asphalt mixtures.",1,https://api.osf.io/v2/files/5d3154a6251f0e00180618bd/,208,https://engrxiv.org/b7gk6/,10.31224/osf.io/b7gk6,,2019-07-19T18:18:14.985766,2019-07-19T18:18:42.761977 | |
| ue47z,"One-Dimensional Numerical Analysis of Cross-Sectional Area Variation Effects on Flow through the Gas Turbine Diffuser","In the paper, a one-dimensional compressible flow of gas inside the gas turbine’s diffuser has been simulated. The modeling has been performed to the aim of obtaining boundary conditions of outlet gas from diffuser and inlet gas to the combustion chamber. Depending on working flow regimes of fluid including subsonic, transonic, and supersonic flows, changes of diffuser cross-section have different effects on gas flow characteristics. For these effects to be correctly imposed, Mach number of the gas flow in each time-step affected by changes of cross-section would be determined, depending on the local Mach number in the same time-step. Obtaining distribution of Mach number along diffuser length, changes in other main characteristics of flow such as pressure, temperature, speed, and density for all of the points along diffuser length would be obtained. In order to verify the validity of the numerical algorithm used, the gas flow would be solved in a divergent nozzle and compared to other numerical methods. In the end, using gas turbine diffuser’s geometrical information, compressible gas flow inside it would be studied using the actual boundary conditions for a 25 MW gas turbine.",1,https://api.osf.io/v2/files/5d2fe5625d2cdc001a02d6fd/,230,https://engrxiv.org/ue47z/,10.31224/osf.io/ue47z,,2019-07-19T18:17:18.397242,2019-07-19T18:17:42.321455 | |
| jm54z,"Chatbot in isiXhosa for Remote Pre/post-Natal Care","In this work we present the development of an isiXhosa ChatBot, a ChatBot developed for pre and postnatal care in the Southern African language of isiXhosa. Multiple implementations of User Interfaces were developed - notably the Android Mobile Application Implementation and the WhatsApp Integration Implementation. We deem this as an enabler for providing first-hand health-care advisors in remote African communities.",1,https://api.osf.io/v2/files/5d2f796c251f0e001804aeea/,227,https://engrxiv.org/jm54z/,10.31224/osf.io/jm54z,,2019-07-18T02:29:18.921559,2019-07-18T02:29:44.225503 | |
| 7kzwv,"Saving water at Cape Town schools by using smart metering and behavioural change","The city of Cape Town suffered a severe water crisis in 2018. At the peak of the drought in South Africa’s Western Cape, a randomised control trial at 105 schools investigated the impact of two behavioural interventions to encourage responsible water usage: detailed water usage data feedback from smart meters, and an interschool competition. Interventions reduced water usage in these schools by 15 to 26%. The information feedback was found to be more effective in reducing night time water use, indicating better water usage by the staff, while the competition was found to be more effective during the day time, indicating better water usage by the pupils. The contrast highlights the way feedback was understood differently by the two groups, with different effects on their assumption of responsibility. This example from Cape Town demonstrates the effectiveness of combining smart technologies with nudges. It provides a model of water conservation interventions for sustainable cities.",1,https://api.osf.io/v2/files/5d2ee8d6835aff00195377f9/,283,https://engrxiv.org/7kzwv/,10.31224/osf.io/7kzwv,,2019-07-17T17:34:43.947139,2019-07-17T19:20:59.737438 | |
| d2ype,"A Novel Method for Developing Compressor’s Characteristic Curves Due to the Guide Vane Stagger Angle Variation","One-dimensional models of analyzing gas turbines as a whole require characteristic curves of pressure coefficient (ψ) based on flow coefficient (φ) and the characteristic curve of compressor’s efficiency of stages so that compressor performance would be predicted. Variation of stagger angle of the stage’s inlet guide vane stated as a geometrical variation of the stage would be resulted in the displacement of pressure coefficient characteristic curve based on the stage’s flow coefficient. Performance nature of compressor stage is in a way that under this condition, the efficiency characteristic curve will remain intact. In this paper, a method would be presented to predict variations of pressure coefficient characteristic curve based on flow coefficient against variations in stagger angle of stage’s guide vane so that one-dimensional modeling of axial flow compressor would be made, through characteristic curves.",1,https://api.osf.io/v2/files/5d2e4eeaa667db0017f621a2/,259,https://engrxiv.org/d2ype/,10.31224/osf.io/d2ype,,2019-07-17T01:36:55.069752,2019-07-25T00:46:34.582242 | |
| 3vbj6,"COMPOSITE PLATES IN POSTBUCKLING: DUAL EXTREMAL VARIATIONAL PRINCIPLES, ENERGY FEATURES, STABILITY, LAY-UP OPTIMALITY CONDITIONS VIA COMPLEMENTARY ENERGY APPROACH","In the present paper the composite plates in postbuckling are explored. The dual extremal variational principles are created. The principles generalize the stationary ones obtained earlier. The stability of the plate near the single-modal bifurcation point is proven. Some useful energy relations are established. It is also demonstrated that the total complementary energy may be considered as a measure of the compliance for the post-buckled composite plate. The latter measure leads to the same lay-up optimality conditions as obtained earlier via the maximization of the total potential energy. Basing on the complementary variational principle, a monotonic plate compliance minimization approach is proposed. The approach allows determining the stiffest lay-up.",1,https://api.osf.io/v2/files/5d2c1607114a42001608ee8a/,147,https://engrxiv.org/3vbj6/,10.31224/osf.io/3vbj6,,2019-07-15T17:54:57.927848,2019-08-19T15:18:08.210380 | |
| 5q4pf,"Smart Product Design for Automotive Systems","Automobiles evolved from primarily mechanical to electro-mechanical, or mechatronic, vehicles. For example, carburetors have been replaced by fuel injection and air-fuel ratio control, leading to order of magnitude improvements in fuel economy and emissions. Mechatronic systems are pervasive in modern automobiles and represent a synergistic integration of mechanics, electronics and computer science. They are smart systems, whose design is more challenging than the separate design of their mechanical, electronic and computer/control components. | |
| In this review paper, two recent methods for the design of mechatronic components are summarized and their applications to problems in automotive control are highlighted. First, the combined design, or co-design, of a smart artifact and its controller is considered. It is shown | |
| that the combined design of an artifact and its controller can lead to improved performance compared to sequential design. The coupling between the artifact and controller design problems is quantified, and methods for co-design are presented. The control proxy function method, which provides ease of design as in the sequential approach and approximates the performance of the co-design approach, is highlighted with application to the design of a passive/ active automotive suspension. Second, the design for component swapping modularity (CSM) of a distributed controller for a smart product is discussed. CSM is realized by employing distributed controllers residing in networked smart components, with bidirectional communication over the network. Approaches to CSM design are presented, as well as applications of the method to a variable-cam-timing engine, and to enable battery swapping in a plug-in hybrid electric vehicle.",1,https://api.osf.io/v2/files/5d2b9b2fa26b3400190aab29/,218,https://engrxiv.org/5q4pf/,10.31224/osf.io/5q4pf,10.1007/s11465-019-0527-0,2019-07-15T17:52:44.411755,2019-07-15T17:53:03.518122 | |
| 7zxhy,"Energy release rate of fiber/matrix interface crack growth in cross-ply laminates under transverse loading: effect of the 0/90 interface and of 0 layer thickness","Models of Representative Volume Elements (RVEs) of cross-ply laminates with different geometric configurations and damage states are studied. Debond growth is characterized by the estimation of the Mode I and Mode II Energy Release Rate (ERR) using the Virtual Crack Closure Technique (VCCT). It is found that the presence of the 0° /90° interface and the thickness of the 0° layer have no effect, apart from laminates with ultra-thin 90° plies where it is however modest. The present analysis supports the claim that debond growth is not affected by the ply-thickness effect.",1,https://api.osf.io/v2/files/5d28bcf045253a00193d5466/,181,https://engrxiv.org/7zxhy/,10.31224/osf.io/7zxhy,,2019-07-12T18:36:23.980932,2019-07-17T11:05:31.174024 | |
| 4m6nj,"Finite Element solution of the fiber/matrix interface crack problem: convergence properties and mode mixity of the Virtual Crack Closure Technique","The bi-material interface arc crack has been the focus of interest in the composite community, where it is usually referred to as the fiber-matrix interface crack. In this work, we investigate the convergence properties of the Virtual Crack Closure Technique (VCCT) when applied to the evaluation of the Mode I, Mode II and total Energy Release Rate of the fiber-matrix interface crack in the context of the Finite Element Method (FEM). We first propose a synthetic vectorial formulation of the VCCT. Thanks to this formulation, we study the convergence properties of the method, both analytically and numerically. It is found that Mode I and Mode II Energy Release Rate (ERR) possess a logarithmic dependency with respect to the size of the elements in the crack tip neighborhood, while the total ERR is independent of element size.",1,https://api.osf.io/v2/files/5d28bb9445253a001a3cccd7/,234,https://engrxiv.org/4m6nj/,10.31224/osf.io/4m6nj,,2019-07-12T18:35:48.581201,2019-07-12T18:36:01.299103 | |
| z76j8,"Energy release rate of the fiber/matrix interface crack in UD composites under transverse loading: debond-debond and debond-free boundary interactions","The effects of crack shielding, finite thickness of the composite and fiber content on fiber/matrix debond growth in thin unidirectional composites are investigated analyzing Representative Volume Elements (RVEs) of different ordered microstructures. Debond growth is characterized by estimation of the Energy Release Rates (ERRs) in Mode I and Mode II using the Virtual Crack Closure Technique (VCCT) and the J-integral. It is found that increasing fiber content, a larger distance between debonds in the loading direction and the presence of a free surface close to the debond have all a strong enhancing effect on the ERR. The presence of fully bonded fibers in the composite thickness direction has instead a constraining effect, and it is shown to be very localized. An explanation of these observations is proposed based on mechanical considerations.",1,https://api.osf.io/v2/files/5d28b952114a42001904e493/,221,https://engrxiv.org/z76j8/,10.31224/osf.io/z76j8,10.1016/j.tafmec.2019.102251,2019-07-12T18:33:13.837710,2019-07-17T11:09:05.662801 | |
| 9y65h,"Dynamic transport mode estimation subject to joint decisions and spatio-temporal variations","This thesis studies the dynamic route and transport mode optimization for participating in a jointly decided activity subject to spatio-temporal variations. Joint activity participants have to travel from their current locations to a common location which is the location of the joint activity. Apart from the recurrent joint activities (such as work, school etc.), there are several joint leisure activities where activity participants have to decide about the location and the starting time of the joint leisure activity along with the transport mode(s) that each one of them has to use for commuting from his/her current location to the joint leisure activity location. | |
| The objective of this thesis is the development of a comprehensive system for the optimization of joint leisure trips that are not related to work by optimizing (a) the location and the starting time of the joint leisure activity (b) the public transport operations (c) the transport mode(s) selection for each activity participant in order to arrive there as fast as possible while satisfying his/her personal trip preferences. | |
| Activities not related to work can be responsible for more than 60\% of trips at an urban environment. Non-working travel patterns differ from the more stable, recurrent travel patterns of work-related activities such as trips from/to work, school etc. and the three main differences of those activities are: (1) The location of a leisure activity can differ on a daily basis (it is not static like the location of the working or studying place); (2) The starting time of a leisure activity has greater elasticity and can differ on a daily basis (it is not stable such as the starting time of work, school etc.); (3) The alternative journey options to and from a leisure activity location are not well-known to the users (users are more aware of their journey alternatives when it comes to transfers from/to work-related activities since those activities are re-current) . | |
| Given that a significant number of transfers is related to leisure activities, the optimization of the (1) location selection, (2) starting activity time, (3) transport mode selection and (4) route selection are of paramount importance for both the commuters' total travel cost and the transport network performance. In addition, the prediction of non-recurrent activities in time and space can be an important step forward for the tactical and dynamic planning of transport networks since the volume and the non-recurrent nature of such activities lead to significant travel demand variations compared to the more stable, work-related activities. | |
| Due to the above, this thesis focuses on: (i) Understanding the State-of-the-Art (SoA) work on utilizing user-generated data for increasing the efficiency level of joint leisure activities and proposing actions towards this direction; (ii) Capturing users' willingness to travel certain distances for participating in different types of activities; (iii) Optimizing the selection of locations and starting times of joint leisure activities (iv) Re-scheduling the starting times of public transportation trips in order to adjust to the joint leisure activity demand without deteriorating the Quality of Service (QoS) for other passengers; (v) Optimizing the journey/path selection of users' who are willing to travel from one point of the network to another for participating at one activity and, possibly, utilize multiple modes while also satisfying their preferences.",1,https://api.osf.io/v2/files/5d28b8cea26b3400190923f0/,346,https://engrxiv.org/9y65h/,10.31224/osf.io/9y65h,,2019-07-12T18:34:49.152836,2019-07-21T14:23:21.868892 | |
| v95rc,"Construction and Demolition Waste in Romania: The Route from Illegal Dumping to Building Materials","The paper performs a critical overview concerning the construction and demolition waste (C&DW) management issues in Romania. Five main stages related to C&DW management are highlighted such as: (i) illegal dumping on public lands; (ii) C&DW collection and disposal in urban landfills; (iii) C&DW treatment and reuse in civil constructions (roads, coating material for landfills); (iv) regional integrated waste management systems; (v) recycling of building materials (e.g., cement industry and recycled aggregates). The paper reveals the poor monitoring of C&DW flows across Romanian counties and the geographical dimension of this waste stream collected by waste operators. The paper examines the current challenges in Romania and it reveals the future prospects to provide a reliable transition towards sustainable C&DW management activities. The targeted route: waste fractions can be recycled and/or reused as building materials via integrated waste management systems, which enable a circular economy in urban and rural municipalities.",1,https://api.osf.io/v2/files/5d28810e45253a00193d1936/,210,https://engrxiv.org/v95rc/,10.31224/osf.io/v95rc,10.3390/su11113179,2019-07-12T18:31:14.562230,2019-07-12T18:31:41.941095 | |
| 6q4zj,"COMPOSITE PLATES AND THEIR LAY-UP SOLUTIONS LEADING TO HIGH BUCKLING AND POST-BUCKLING RESISTANCE","At the beginning of the present paper, the post-buckled composite plates are examined. The plates have a symmetric lay-up. The layer orientation angles vary in a point-wise way or in a plate-wise way. The von Karman theory describes a plate behavior. For a plate stiffness maximization problem the first-order optimality conditions are derived. In the conditions, the essential roles play the mid-plane principal strains and the principal curvatures. The optimality conditions may lead to a co-axiality of some structural tensors. Analytical examples illustrate the solutions of such types. Further, several numerical examples are presented. In the examples, the plates are loaded by shear and have the high buckling-resisting ability also. A significant conclusion of the paper is that in the properly designed lay-up the outermost layers and the innermost layers play different roles. The former ones withstand mainly buckling, and the latter ones withstand mainly post-buckling. The innermost layers have the orientation angle rather close to 0°. The weight reduction opportunities are demonstrated.",1,https://api.osf.io/v2/files/5d26daac114a42001604b148/,243,https://engrxiv.org/6q4zj/,10.31224/osf.io/6q4zj,,2019-07-11T20:31:40.721525,2019-07-11T20:32:06.686758 | |
| fkjeg,"Isolating and Expanding Endothelial Progenitor Cells from Peripheral Blood on Peptide‐functionalized Polystyrene Surfaces","The expansion of human peripheral blood endothelial progenitor cells to obtain therapeutically relevant endothelial colony forming cells (ECFCs) has been commonly performed on xeno‐derived extracellular matrix proteins. For cellular therapy applications, xeno‐free culture conditions are desirable to improve product safety and reduce process variability. We have previously described a novel fluorophore‐tagged RGD peptide (RGD‐TAMRA) that enhanced the adhesion of mature endothelial cells in vitro. To investigate whether this peptide can replace animal‐derived extracellular matrix proteins in the isolation and expansion of ECFCs, peripheral blood mononuclear cells from 22 adult healthy adult donors were seeded on RGD‐TAMRA‐modified polystyrene culture surfaces. Endothelial colony formation was significantly enhanced on RGD‐TAMRA‐modified surfaces compared to the unmodified control. No phenotypic differences were detected between ECFCs obtained on RGD‐TAMRA compared to ECFCs obtained on rat tail collagen‐coated surfaces. Compared to collagen‐coated surfaces and unmodified surfaces, RGD‐TAMRA surfaces promoted ECFC adhesion, cell spreading, and clonal expansion. This work presents a platform that allows for a comprehensive in vitro evaluation of peptide‐based biofunctionalization as a promising avenue for ex vivo ECFC expansion.",1,https://api.osf.io/v2/files/5d25ecd4a26b34001806faf9/,235,https://engrxiv.org/fkjeg/,10.31224/osf.io/fkjeg,10.1002/bit.27107,2019-07-10T20:35:42.288109,2019-07-10T20:36:03.171520 | |
| te5jx,"Atomization and combustion characteristics of a fuel–water rapid internal mixing injector","In this study, we investigated the atomization characteristics of rapid internal mixing injector (RIM injector) developed in our laboratory. RIM injector successfully emulsifies base fuel without any surfactant just before fuel injection. The diameter of droplet discharged from RIM injector was evaluated based on processing of shadowgraph images. It was found that Sauter mean diameter (SMD) of droplet is determined by the gas to liquid ratio (GLR) and viscosity of emulsified fuel. The increasing GLR decreases SMD value. As water content ratio is increased, the inner structure of droplet changes to W/O type emulsion. The emulsification increases its viscosity, which deteriorates the atomization characteristics. We proposed an empirical formula as functions of GLR and Reynolds number reproducing the deterioration resulting from increasing viscosity. The formula successfully predicts the SMD variation with respect to GLR and water content ratio. Finally, we examined the effect of atomization air ratio on NOx and PM emissions. The quantity of atomization air significantly influences the PM emission because the increasing air improves the mixing of fuel vapor with combustion air.",1,https://api.osf.io/v2/files/5d257502114a42001802b5a6/,153,https://engrxiv.org/te5jx/,10.31224/osf.io/te5jx,,2019-07-10T20:34:34.451353,2019-08-24T14:31:09.133552 | |
| 2w3dt,"FÜNFTE-MIAM technique for biochemical embryology problems","July 2018 [Genes and Cells 13(2 (Suppl. 1)):58-59] Project: RFBR_16-32-00914 ""Development of the novel physical methods for complex biomedical diagnostics based on position - sensitive mapping with the angular resolution at the tissue and cellular levels using analytical labs-on-a-chip""",1,https://api.osf.io/v2/files/5d24bfa145253a001b39d9cb/,216,https://engrxiv.org/2w3dt/,10.31224/osf.io/2w3dt,,2019-07-09T18:45:02.300870,2019-07-09T18:45:23.809210 | |
| rcw3e,"Large-amplitude Dithering Mitigates Glitches in Digital-to-analogue Converters","This paper develops and experimentally evaluates a dither-based method for improved generation of arbitrary signals in digital-to-analogue converters that exhibits glitches --- essentially converting the glitches from high-frequency to low-frequency disturbances. One major benefit of this behaviour appears in closed-loop control applications, as the glitch disturbance can be moved from outside control law bandwidth to inside control law bandwidth, enabling suppression by feedback. A behavioural model of glitches is presented and the effect of applying a dither signal is analysed in detail. Analytical and experimental results demonstrate that a dither signal with sufficiently large amplitude can mitigate the effect of glitches, when used in conjunction with a low-pass filter. Severe glitches appear in various digital-to-analogue converter topologies, including converter topologies that are used in high-precision motion control applications, such as adaptive optics and scanning force microscopy. Glitches introduce impulse-like disturbances which have a broadband frequency distribution. Low-pass filtering alone does not provide sufficient attenuation, and in applications with feedback control only frequency content within the control law bandwidth is attenuated. Hence, a high-frequency disturbance such as a glitch will not be suppressed. The use of dithering to suppress glitches is therefore beneficial in applications where errors in signal conversion are a primary concern, such as high-precision motion control or accurate reference signal generation.",1,https://api.osf.io/v2/files/5d23a8a545253a001b39197c/,225,https://engrxiv.org/rcw3e/,10.31224/osf.io/rcw3e,,2019-07-08T20:49:05.025343,2019-07-08T20:49:23.120949 | |
| 5xktq,"Reducing the Error of an Averaged Quantiser in the Presence of a Small-Scale Dither Signal","A method to improve the reconstruction of a signal after quantisation by compensation of a systematic error is presented. The result is that the effective resolution of a quantiser can be increased. This is possible due to the smoothing effect of adding a dither signal before quantisation, and subsequent averaging. The method requires that the type of probability distribution of the dither signal and the step-size of the quantiser are known. An analysis of the error in the recovered signal is presented, and optimal variances for a normally distributed dither are presented for signals that have either large or small magnitudes compared to the quantiser step-size. A method for determining the dither probability distribution parameters from the quantised signal is also presented. This makes it possible to determine the dither probability distribution parameters in systems where it is not possible to exert accurate control over the added dither signal and therefore enable to use of the presented reconstruction method under such circumstances.",1,https://api.osf.io/v2/files/5d239e58a26b340017057c40/,234,https://engrxiv.org/5xktq/,10.31224/osf.io/5xktq,,2019-07-08T20:04:49.470887,2019-07-08T20:05:07.174877 | |
| axsjd,"Experimental demonstration of data predictive control for energy optimization and thermal comfort in buildings","Model Predictive Control for room temperature control in buildings is an effective approach to energy management in buildings. However, the development and maintenance of physical models may be a bottleneck for widespread real life application. Data Predictive Control is an attempt to address this problem by learning the behaviour of the building from historical data and thus reducing the modelling effort. Here, we present an application of a Data Predictive Control approach, based on Random Forests with affine functions and convex optimization, to control the room temperature in a real life apartment. When compared to a conventional hysteresis controller, the applied approach saves 24.9 % of cooling energy while reducing the integral of comfort constraint violations by 72.0 % in a six-day experiment.",1,https://api.osf.io/v2/files/5d1b5a244994dd001a16c9fe/,347,https://engrxiv.org/axsjd/,10.31224/osf.io/axsjd,,2019-07-02T13:44:39.007363,2019-07-02T14:07:27.450770 | |
| pfys6,"Collaborating with Style: Using an Agent-Based Model to Simulate Cognitive Style Diversity in Problem Solving Teams","Collaborative problem solving can be successful or counterproductive. The performance of collaborative teams depends not only on team members' abilities, but also on their cognitive styles. Cognitive style measures differences in problem-solving behavior: how people generate solutions, manage structure, and interact. While teamwork and problem solving have been studied separately, their interactions are less understood. This paper introduces the KAI Agent-Based Organizational Optimization Model (KABOOM), the first model to simulate cognitive style in collaborative problem solving. KABOOM simulates the performance of teams of agents with heterogeneous cognitive styles on two contextualized design problems. Results demonstrate that, depending on the problem, certain cognitive styles may be more effective than others. Also, intentionally aligning agents' cognitive styles with their roles can improve team performance. These experiments demonstrate that KABOOM is a useful tool for studying the effects of cognitive style on collaborative problem solving.",1,https://api.osf.io/v2/files/5d1b484774f2b200186f5f98/,253,https://engrxiv.org/pfys6/,10.31224/osf.io/pfys6,,2019-07-02T12:39:58.732381,2019-07-02T12:40:21.532511 | |
| s4b68,"KABOOM: An Agent-Based Model for Simulating Cognitive Sale in Team Problem Solving","The performance of a design team is influenced by each team member's unique cognitive style - i.e., their preferred manner of managing structure as they solve problems, make decisions, and seek to bring about change. Cognitive style plays an important role in how teams of engineers design and collaborate, but the interactions of cognitive style with team organization and processes have not been well studied. The limitations of small-scale behavioral experiments have led researchers to develop computational models for simulating teamwork; however, none have modeled the effects of individuals' cognitive styles. This paper presents KABOOM (KAI Agent-Based Organizational Optimization Model), the first agent-based model of teamwork to incorporate cognitive style. In KABOOM, heterogeneous agents imitate the diverse problem-solving styles described by Kirton's Adaption-Innovation construct, which places each individual somewhere along the spectrum of cognitive style preference. Using the model, we investigate the interacting effects of a team's communication patterns, specialization, and cognitive style composition on design performance. By simulating cognitive style in the context of team problem solving, KABOOM lays the groundwork for the development of team simulations that reflect humans' diverse problem-solving styles.",1,https://api.osf.io/v2/files/5d1b47c974f2b200196f4949/,244,https://engrxiv.org/s4b68/,10.31224/osf.io/s4b68,,2019-07-02T12:39:20.184836,2019-07-02T12:39:42.010309 | |
| acw8z,"Wirelessly powered and remotely controlled valve-array for highly multiplexed analytical assay automation on a centrifugal microfluidic platform","In this paper we present a wirelessly powered array of 128 centrifugo-pneumatic valves that can be thermally actuated on demand during spinning. The valves can either be triggered by a predefined protocol, wireless signal transmission via Bluetooth, or in response to a sensor monitoring parameters like temperature or homogeneity of the dispersion. Upon activation of a resistive heater, a low-melting membrane (ParafilmTM) is removed to vent an entrapped gas pocket, thus letting the incoming liquid wet an intermediate dissolvable film and thus open the valve. The proposed system allows up to 12 heaters to be activated in parallel with a response time below 3 seconds, potentially, resulting in 128 actuated valves in under 30 seconds. We demonstrate with three examples of common and standard procedures how the proposed technology could become a powerful tool for implementing diagnostic assays on Lab-on-a-Disc. First, we implement wireless actuation of 64 valves during rotation in a freely programmable sequence, or upon user input in real time. | |
| Then, we show a closed-loop centrifugal flow control sequence where the state of mixing between reagents evaluated from stroboscopically recorded images triggers the opening of valves. In our last experiment valving and closed-loop control are used to facilitate centrifugal processing of whole blood.",1,https://api.osf.io/v2/files/5d19d0f74994dd001914faf4/,296,https://engrxiv.org/acw8z/,10.31224/osf.io/acw8z,10.1016/j.bios.2018.03.012,2019-07-01T21:19:07.425155,2019-07-01T21:19:23.181684 | |
| 5wy8s,"Fees and governance: Towards sustainability in water resources management at schools in post-apartheid South Africa","Water scarcity is increasingly staking a claim next to energy as a threat to the sustainability of large cities, especially in developing countries with limited resources. The recent crisis brought on by Cape Town’s “Day Zero” drought created the impetus to expand on existing research on water demand management to include analysis of school usage patterns and key determinants thereof. With the effects of apartheid still visible in society and in school infrastructure coupled with the high water usage rates at schools, this paper evaluates the impact of school affluence (whether it is fee-paying or not, and self-governing or not) on water usage. We find that poor schools use substantially more water, partially because of poor maintenance, with mean water efficiencies of poor schools around 50% and 80% for affluent schools. Bayesian models were used to further determine which characteristics of a school are good proxies for the higher usage to help administrators and policy makers in the resource constrained educational environment. In addition to the obvious impact of maintenance, the results point an incriminatory finger at early morning-school usage, early afternoon usage, and Saturday usage",1,https://api.osf.io/v2/files/5d19cf5d1fde860019ac82f6/,248,https://engrxiv.org/5wy8s/,10.31224/osf.io/5wy8s,10.1016/j.scs.2019.101694,2019-07-01T21:15:11.547651,2019-08-06T08:36:37.194793 | |
| kr2gx,"The eLoaD platform endows centrifugal microfluidics with on-disc power and communication","In this paper we present a comprehensive description of the design, fabrication and operation of an electrified Lab-on-a-Disc (eLoaD) system. The smart platform is developed to extend conventional Lab-on-a-Disc applications with an electronic interface, providing additional flow control and sensing capabilities to centrifugal microfluidics platforms. Wireless power is transferred from a Qi-compliant transmitter to the eLoaD platform during rotation. An Arduino-based microcontroller, a Bluetooth communication module, and an on-board SDcard are integrated into the platform. This generalises the applicability of the eLoaD and its modules for performing a wide range of laboratory unit operations, procedures, or diagnostic assays, all controlled wirelessly during spinning. The lightweight platform is fully reusable and modular in design and construction. An interchangeable and non-disposable application disc is fitted with the necessary sensors and/or actuators for a specific assay or experiment to be performed. A particular advantage is the ability to continuously monitor and interact with LoaD experiments, overcoming the limitations of stroboscopy. We demonstrate the applicability of the platform for three sensing experiments involving optical, electrochemical, and temperature detection, and one actuation experiment involving controlled heating/cooling. The complete electronic designs and example programming codes are extensively documented in the supplementary material for easy adaptation.",1,https://api.osf.io/v2/files/5d19cdfe4994dd001714eb11/,315,https://engrxiv.org/kr2gx/,10.31224/osf.io/kr2gx,10.1016/j.bios.2018.05.056,2019-07-01T21:17:50.929316,2019-07-01T21:18:07.644403 | |
| 8kz6q,"Net-societal and Net-private Benefits of Some Existing Vehicle Crash Avoidance Technologies","Most light-duty vehicle crashes occur due to human error. Many of these crashes could be avoided or made less severe with the aid of crash avoidance technologies. These technologies can assist the driver in maintaining control of the vehicle when a possibly dangerous situation arises by issuing alerts to the driver and in a few cases, responding to the situation itself. This paper estimates the societal and private benefits and costs associated with three crash avoidance technologies, blind-spot monitoring, lane departure warning, and forward-collision warning, for all light duty passenger vehicles in the U.S. for the year 2015. The three technologies could collectively prevent up to 1.6 million crashes each year including 7,200 fatal crashes. In this paper, the authors estimated the net-societal benefits to the overall society from avoiding the cost of the crashes while also estimating the private share of those benefits that are directly affecting the crash victims. For the first generation warning systems, net-societal benefits and net-private benefits are positive. Moreover, the newer generation of improved warning systems and active braking should make net benefits even more advantageous.",1,https://api.osf.io/v2/files/5d18302f8a17d500160578c3/,274,https://engrxiv.org/8kz6q/,10.31224/osf.io/8kz6q,10.1016/j.aap.2019.02.003,2019-06-30T13:21:24.143425,2019-06-30T13:21:46.176939 | |
| mb5t9,"Risk Assessment for Cyber Security of Manufacturing Systems: A Game Theory Approach","This paper presents a novel approach using game theory to assess the risk likelihood in manufacturing systems quantifiably. Cybersecurity is a pressing issue in the manufacturing sector. Nevertheless, managing the risk in cybersecurity has become a critical challenge for modern manufacturing enterprises. In risk management thinking, the first step is to identify the risk, then validate it, and lastly, consider responses to the risk. If the risk is below the security risk appetite of the manufacturing system, it could be accepted. However, if it is above the risk appetite, the system should appropriately respond by either avoiding, transferring, or mitigating the risk. The validation of the risk in terms of severity and likelihood of the threat, however, is challenging because the later component is hard to quantify. In this paper, Failure Modes and Effects Analysis (FMEA) method is modified by employing game theory to quantitatively assess the likelihood of cyber-physical security risks. This method utilizes the game theory approach by modeling the rivalry between the attacker and the system as a game and then try to analyze it to find the likelihood of the attacker’s action. We first define players of the game, action sets, and the utility function. Major concerns of cyber security issues in the manufacturing area are carefully considered in defining the cost function composed of defense policy, loss in production, and recovery. A linear optimization model is utilized to find a mixed-strategy Nash Equilibrium, which is the probability of choosing any action by the attacker also known as the likelihood of an attack. Numerical experiments are presented to further illustrate the method. Forecasting the attacker’s behavior enables us to assess the cybersecurity risk in a manufacturing system and thereby be more prepared with plans of proper responses.",1,https://api.osf.io/v2/files/5d1696ec8a17d5001604edd6/,318,https://engrxiv.org/mb5t9/,10.31224/osf.io/mb5t9,,2019-06-29T00:05:34.970605,2019-06-29T00:06:09.597115 | |
| 3wt5j,"Design and Preliminary Results of a Reaction Force Series Elastic Actuator for Bionic Ankle Prostheses","The TF8 actuator is an untethered, lower-extremity powered-prostheses designed to replicate biological kinetic and kinematic function of ankles. An energy optimal hardware specification was found by kinematically clamping walking gait data to the dynamic model of a series elastic actuator (SEA). We searched for a minimal electrical energy configuration of motor, reduction ratio, and spring, subject to specified constraints and ultimately discretely available components. The outcome translated into a mechanical design that heavily weighted the importance of mechanical energy storage in springs. The resulting design is a moment-coupled cantilever-beam reaction-force SEA (RFSEA) that has a nominal torque rating of 85Nm, peak torque of 175Nm, 105 degree range of motion, and a hardware mass of 1.6kg.",1,https://api.osf.io/v2/files/5d166c148a17d5001904db4d/,125,https://engrxiv.org/3wt5j/,10.31224/osf.io/3wt5j,,2019-06-29T00:02:39.351953,2019-10-18T20:39:41.996243 | |
| swt34,"Energetic Consequences of Series and Parallel Springs in Lower-Extremity Powered Prostheses","We present electric energetic consequences for mechanical design trade-offs in lower-extremity powered prostheses. There are four main hardware components commonly implemented in these devices that can be tuned to achieve desired performance: motor, reduction ratio N, series spring stiffness Ks, and parallel spring stiffness Kp. The allowed joint range of motion is a fifth parameter that can also drastically change energy consumption. We apply a kinematically clamped analysis to the system equations to map the electric cost of transport (COT) for knee and ankle level-ground walking, in addition to ankle stair ascent and descent. We also utilize an optimization procedure to identify minimum energy hardware configurations. The energy map provides insight into consequences of variance from optimal parameters. Our results support the contribution of the series elastic element for improved power output. Parallel stiffness can provide up to 8% improvements in walking with minimal negative effect with varied terrain, and a varying ankle transmission ratio can similarly improve COT by 8% from level-ground to stair ascent. Limited dorsiflexion can further improve COT by 30%. These observations can provide the designer clarity to how design decisions modulate hardware performance.",1,https://api.osf.io/v2/files/5d1663397c9eb700192b9657/,271,https://engrxiv.org/swt34/,10.31224/osf.io/swt34,,2019-06-28T23:47:43.363089,2019-06-28T23:48:07.337728 | |
| 6b75s,"State of Health Estimation and Prediction of Fuel Cell Stacks in Backup Power Systems","Fuel cell based backup systems are used as telecommunication power supplies, where availability of power is crucial for a reliable service. State of health (SOH) is a useful metric in aiding predictive maintenance actions, that aim to reduce the system down time as well as the operating cost. In this paper, voltage, current, and temperature data from numerous stacks installed in the field to estimate an SOH metric. A long short term memory (LSTM) recurrent neural network (RNN) is trained to predict SOH values six months into the future. Finally, the RNN performance is evaluated on prediction horizons of six months, as well as longer horizons of twelve, eighteen, and twenty-four months.",1,https://api.osf.io/v2/files/5d15d6ce7c9eb700192b4b9a/,196,https://engrxiv.org/6b75s/,10.31224/osf.io/6b75s,,2019-06-28T23:47:13.501120,2019-06-28T23:47:21.398069 | |
| 38bqx,"Quantifying Consciousness: Electrophysiological Perspective","This article aims to provide a new electrophysiological metric, namely, brain energy. Based on the literature review, this metric is expected to quantify the human global visual awareness, namely because it suggests the use of binocular rivalry setup. The article also offers simple ways to build up binocular rivalry experiments.",1,https://api.osf.io/v2/files/5d141909b95393001972d624/,223,https://engrxiv.org/38bqx/,10.31224/osf.io/38bqx,,2019-06-27T02:15:09.232775,2019-11-05T14:21:19.647255 | |
| 9c3vk,"Linking Dynamics Between Pupil and Lens","This article aims to measure pupil variations through real physical stimuli in a real world; and to link them with lens accommodation theories. It is concluded that pupil dilation is linked to rounded lens, and pupil constriction is linked to faltered lens.",1,https://api.osf.io/v2/files/5d13ea2165ffa5001a213882/,215,https://engrxiv.org/9c3vk/,10.31224/osf.io/9c3vk,,2019-06-26T22:20:19.167361,2019-10-20T19:00:22.065656 | |
| am7xs,"COMPARISON BETWEEN TWO MODELING ASPECTS TO INVESTIGATE SEISMIC SOIL STRUCTURE INTERACTION IN A JOINTLESS BRIDGE","Seismic waves propagate through a series of rock and soil layers before they interact with the foundation and superstructure. Besides the original characteristics of the earthquake motion at the instant of fault rupture, it is also important how the soil site responds in terms of amplification or de-amplification of different frequency contents. Considering possible nonlinear response of soil and structure, a coupled soilstructure model is required to efficiently capture the dynamic behavior of the entire system. This paper focuses on comparison of two modelling strategies for Soil-Structure Interaction (SSI) aiming to define the behavior of a jointless bridge, namely (a) one with an explicit full-scale soil domain with bridge model and (b) another with Beam on Dynamic Winkler Foundation (BDWF)/ nonlinear soil springs. Finally, the structural components that effect overall behavior of superstructure is compared between these two models and the variation of seismic response from performance-based study is discussed.",1,https://api.osf.io/v2/files/5d1279b3693ba800188f1922/,300,https://engrxiv.org/am7xs/,10.31224/osf.io/am7xs,,2019-06-25T20:10:26.826228,2019-06-27T22:42:03.536050 | |
| 78ra4,"Visual and Statistical Methods to Calculate Interrater Reliability for Time-Resolved Qualitative Data: Examples from a Screen Capture Study of Engineering Writing Patterns","Traditionally, interrater reliability (IRR) is determined for easily defined events, such as deciding within which category a piece of qualitative data falls. However, for time-resolved or time-dependent observational data and other nontraditional data, complications arise due to the complexity of the data being interpreted and analyzed. In this paper, we present two promising new methods for calculating IRR based on visual representations of analyzed time-resolved data. We compare the IRR calculated using these two visual methods with five of the most common statistical measures for calculating IRR, finding excellent agreement between our new methods and existing statistical formulae. This methods development is exemplified using data for our ongoing research, in which we are working to analyze time-resolved engineering writing data recorded through screen capture technology. The process of developing methods of interrater reliability for our context can also be applied to other researchers who seek to analyze non-traditional data, such as those collected during eye-tracking, screen capture, or observational studies.",1,https://api.osf.io/v2/files/5d10ff50693ba800178ffef0/,229,https://engrxiv.org/78ra4/,10.31224/osf.io/78ra4,,2019-06-24T22:24:25.816736,2019-07-16T15:52:59.887799 | |
| p49e8,"Build Orientation Optimization for Strength Enhancement of 3-D Printed Parts Using Machine Learning based Algorithm","The layered fabrication approach induces directional anisotropy and impacts the mechanical strength of FDM components significantly. This paper proposes a generalized machine learning based parameter optimization framework to determine optimal build orientation for FDM components. The algorithm determines ideal build orientation by maximizing the minimum Factor of Safety (FoS) for the component under prescribed loading conditions ensuring its even distribution. An Artificial Neural Network (ANN) coupled with Bayesian algorithm has been employed to accelerate the optimization process. The algorithm begins with an initial sample data collected using a brute force approach; uses single layered ANN for approximation and optimization is achieved using a Bayesian algorithm. A series of computational experiments considering five different test components have been devised to evaluate the performance and efficacy of the proposed algorithm. These experiments demonstrated that the proposed algorithm can determine the optimum building orientation effectively with certain limitations.",1,https://api.osf.io/v2/files/5d10fd74693ba800188e3190/,236,https://engrxiv.org/p49e8/,10.31224/osf.io/p49e8,10.14733/cadconfP.2019.232-236,2019-06-24T22:22:04.122853,2019-06-25T13:03:03.873224 | |
| jvhnr,"The impact of running-in on the friction of an automotive Gasoline-engine and in particular on its piston assembly and valve-train","Generally, mating surfaces that are in tribological contact undergo a running-in process at the beginning of their | |
| operational lifetime. During this running-in phase the tribological operating condition change significantly leading ideally | |
| to long term operation with a minimum of continuous wear. While this process and its duration is rather well understood | |
| for single machine elements like journal bearings, it is the aim of this work to investigate the running-in behaviour of | |
| more complex systems like an internal combustion engine and its sub-assemblies. To gain insight into the influence | |
| and duration of this running-in phase a series of tests have been performed under realistic engine operating conditions. | |
| To be able to separate the running-in processes for the individual subsystems piston assembly, valve-train and journal | |
| bearings of the crank train, a large series of tests have been conducted for a conventional gasoline passenger car | |
| engine. The results show a strong influence of the running-in process on total engine friction, which can be attributed | |
| mostly to the direct acting valve-train and to a considerably lesser extent to the piston assembly.",1,https://api.osf.io/v2/files/5d10eb23e200da00186e5f03/,230,https://engrxiv.org/jvhnr/,10.31224/osf.io/jvhnr,10.1177/1350650117727231,2019-06-24T22:08:50.545349,2019-06-25T13:01:23.453928 | |
| 5mtq6,"A COMPLEMENTARY ENERGY THEOREM FOR COMPOSITE PLATES IN POSTBUCKLING","A composite von Karman plate in postbuckling is considered. Using the first Piola stress tensor and the displacement gradient tensor, a complementary energy variational theorem is proven. The proof is given in the case of symmetric lay-up. According to the theorem, at the actual stress state of the plate the complementary energy (as a function of the internal forces and of the moments) reaches its stationary value. The stationary feature of the actual state is valid as compared to other states satisfying the static equilibrium and the static boundary conditions. It is shown how the theorem may be generalized to the case of a non-symmetric lay-up.",1,https://api.osf.io/v2/files/5d10b431e200da00176e9e34/,221,https://engrxiv.org/5mtq6/,10.31224/osf.io/5mtq6,,2019-06-24T22:07:37.352057,2019-07-04T15:35:42.843443 | |
| 4unxj,"Numerical modeling of nanobundle- and nanorope- reinforced polymer mechanical properties","Carbon nanotubes (CNTs) demonstrate unusually high stiffness, strength and resilience, and are ideal reinforcing materials for polymer-based nanocomposites. Van der Waals interactions between the nanotubes often result in formation of nanotube bundles and/or ropes. Determination of mechanical properties of the nanobundle- and nanorope-based nanocomposites is difficult due to the complicated geometries of the reinforcement structures. However, in order to better utilize nanocomposites, it is crucial to determine mechanical properties of nanocomposites in their real form as much as possible. In this paper, the elasticity theory for anisotropic body and continuum modeling are used to determine effective mechanical properties of bundle and nanorope-based nanocomposites. Numerical models are developed using a Representative Volume Element (RVE) consisting of nanoropes and nanobundles made up of different numbers of nanotubes to investigate the effect of nanorope geometry on nanocomposite mechanical properties. Models of several RVEs are developed with nanoropes consisting of five, seven, nine, and thirteen CNTs. CNT volume fraction is kept constant in all models for a valid comparison. Also, the effect of matrix modulus on the strengthening efficiency of CNTs is investigated. The results indicate that nanocomposite longitudinal modulus decreases with increasing the number of CNTs in the nanorope.",1,https://api.osf.io/v2/files/5d0da3323d6264001968eaa9/,176,https://engrxiv.org/4unxj/,10.31224/osf.io/4unxj,,2019-06-22T12:49:54.415338,2019-07-01T21:31:57.416216 | |
| 9n5mc,"Isothermal Thermogravimetric Analysis of Recycled Carbon Fiber Composites","Isothermal Thermogravimetric Analysis (TGA) is a technique in which the mass of a substance is monitored as a function of time as the sample specimen is subjected to a controlled temperature program in a controlled atmosphere. In this research, isothermal TGA was carried out to determine the thermal stability of the recycled epoxy-based and vinyl ester-based carbon fiber composite (CFC). The specimens were heated at constant temperature under nitrogen and air. We evaluate the influence of different temperature on the degradation of recycled CFCs. Results indicate that different temperature has significant influence on the degradation of the recycled CFC under nitrogen.",1,https://api.osf.io/v2/files/5d0da2c93d6264001868f83a/,185,https://engrxiv.org/9n5mc/,10.31224/osf.io/9n5mc,,2019-06-22T12:45:43.001464,2019-07-01T21:34:14.712468 | |
| 7kc3f,"Dynamic Thermogravimetric Analysis of Recycled Carbon Fiber Composites: Mini Review","Thermogravimetric analysis (TGA) is one of the most popular analysis techniques to study the decomposition process of polymeric materials in controlled atmospheres at various temperatures. In this review, dynamic TGA was carried out to determine the thermal stability of the recycled epoxy-based and vinyl ester-based carbon fiber composite (CFC). The specimens were heated from ambient to 800 oC under nitrogen and air at different heating rates. Results indicates that different heating rates has no significant influence on the degradation of the epoxy- based CFC.",1,https://api.osf.io/v2/files/5d0da23d3d626400176936d4/,189,https://engrxiv.org/7kc3f/,10.31224/osf.io/7kc3f,,2019-06-22T12:38:42.802804,2019-07-01T21:35:39.044756 | |
| p5xcd,"Humanoid Eyes: Perspective & Challenges","This article gives perspective and explains the challenges to optimizing the humanoid eyes.",1,https://api.osf.io/v2/files/5d0d40c0693ba800178cc096/,240,https://engrxiv.org/p5xcd/,10.31224/osf.io/p5xcd,,2019-06-22T12:34:27.181946,2019-10-20T22:11:28.065331 | |
| k2rwp,"LAY-UP OPTIMALITY CONDITIONS FOR STIFFNESS MAXIMIZATION OF ANISOTROPIC COMPOSITE PLATES IN POSTBUCKLING","The present paper deals with the optimization of post-buckled composite plates. The plates have a symmetric lay-up. The layer orientation angles vary in the point-wise or in the plate-wise ways. The von Karman theory is employed. The boundary conditions are the simple support ones or the clamped ones. The structural potential energy is treated as a measure of structural stiffness. For the plate stiffness maximization problem, the first-order necessary conditions of the local optimality are derived. The mathematical treatment of the conditions is performed. The conditions contain two terms. One of them corresponds to the mid-plane strains; another one corresponds to the plate curvatures. The optimality conditions may lead to a co-axiality of some structural tensors. An illustration of the optimality conditions is presented.",1,https://api.osf.io/v2/files/5d0b6ce83466a6001c9190c8/,228,https://engrxiv.org/k2rwp/,10.31224/osf.io/k2rwp,,2019-06-20T17:16:41.753184,2019-06-20T17:18:07.088368 | |
| 8sxh9,"Implementing Kaizen through a Lean RACE Model: A Case Study","In this case study, we conducted a Kaizen implementation to eliminate waste in a quick shipping area of a manufacturing facility. Based on Toyota’s seven types of waste, specific wastes in the system are identified, and the improvement opportunities are specified. The lean RACE (Reduce, Accelerate, Consolidate, Enhance) model is then implemented to identify improvement targets in four directions: Reduce non-value-added activities to decrease interruption in the flow, Accelerate value-added activities to improve throughput and lead time, Consolidate value-added processes into fewer steps in order to shorten the value stream, and Enhance the value added through the processes to improve customer satisfaction and employee welfare such as the ergonomics of work and safer work environment. Based on the collected data, a numerical study is conducted through simulation modeling to verify the benefits of the Kaizen plan. The use of the RACE model, in this case, has projected results of reduction in transportation waste, less handling of work in process, and less waiting which leads to reduction in cycle time and increased throughput.",1,https://api.osf.io/v2/files/5d0956e811bd080017a06172/,222,https://engrxiv.org/8sxh9/,10.31224/osf.io/8sxh9,,2019-06-19T03:55:07.605067,2019-06-19T03:55:24.835565 | |
| 9f8bt,"Factors Contributing to Success in an Introductory Mechanical Engineering Course: A Data-Driven Case Study","Recent studies have paid attention to the success and performance of students in higher education, concerned finding significant contributing factors. This paper attempts to examine and investigate the effect of a number of factors on students’ success in engineering courses. The data was collected from an introductory course, the Engineering Graphics and Practice, in the mechanical engineering department at the University of Texas at San Antonio (UTSA) during fall 2018 semester. The level of students in the class is mixed. Although this course is primarily designed for freshmen, there are upper-division students (juniors and seniors). The study finds that attendance and homework have the most significant effects on the overall performance of students in the course. Surprisingly, a counterintuitive finding is that the effect of a student’s class level is insignificant. The upper-division students did not outperform those in a lower division. Ultimately, the finding of this paper proves that active learning has a greater impact on a student’s overall performance than a number of earned credits.",1,https://api.osf.io/v2/files/5d0955ae11bd0800189f9506/,229,https://engrxiv.org/9f8bt/,10.31224/osf.io/9f8bt,,2019-06-19T03:54:16.408879,2019-06-19T03:54:41.908085 | |
| d6fh9,"Cybersecurity Concerns for Total Productive Maintenance in Smart Manufacturing Systems","Maintenance is the core function to keep a system running and avoid failure. Total Productive Maintenance (TPM) has broadly utilized maintenance strategy to improve the customer's satisfaction and hence obtain a competitive advancement. However, the complexity of smart manufacturing systems due to the recent advancements, specifically the integration of internet and network systems with traditional manufacturing platforms, has made this function more challenging. The focus of this paper is to explain how cybersecurity could impact the TPM by affecting the overall equipment effectiveness (OEE) in a smart manufacturing system by providing a structured literature survey. First, it provides concerns on principle of TPM regarding cybersecurity in smart manufacturing systems. Then, it highlights the effect of a variety of cyber-physical threats on OEE, as a main key performance indicator of TPM and how differently they can reduce OEE. The countermeasures that could be considered to compensate for the negative impact of a cybersecurity threat on the overall effectiveness of the system also will be discussed. Finally, research gaps and challenges are identified to improve overall equipment effectiveness (OEE) in presence of cybersecurity threats in critical manufacturing industries.",1,https://api.osf.io/v2/files/5d0940c811bd0800199fb2e8/,366,https://engrxiv.org/d6fh9/,10.31224/osf.io/d6fh9,,2019-06-19T03:53:08.639374,2019-06-19T03:53:27.773363 | |
| y7f53,"A thermodynamically consistent chemo-mechanically coupled large deformation model for polymer oxidation","In this work, we present a continuum-level thermodynamically consistent model for high temperature oxidation in | |
| polymers, that incorporates the coupling between diffusion, chemical reaction and large deformation behavior of | |
| polymers. The specific constitutive forms are derived based on the thermodynamic inequality conditions and the | |
| kinetics of the oxidative reactions are considered. Oxidative shrinkage has also been considered in the kinematics as | |
| an irreversible effect. Subsequently, the model is implemented in ABAQUS/Standard to analyze numerically the | |
| coupled diffusion-reaction behavior of polymers undergoing oxidation. Several numerical simulations are performed to | |
| understand the effect of various material parameters on the oxidative response. The model is capable of predicting the | |
| heterogeneous oxidation profile within a thick polymer sample. It can also track the growth of oxide layer in the case of | |
| a long-term thermo-oxidative aging process. The model can be used to simulate the oxidation process involving | |
| complex geometries (as fiber reinforced composites) fairly easily under various ambient conditions.",1,https://api.osf.io/v2/files/5d07ea0a0bea130019b6f9c8/,217,https://engrxiv.org/y7f53/,10.31224/osf.io/y7f53,,2019-06-17T20:22:15.182284,2019-06-18T17:36:29.695557 | |
| a5d3z,"Building The Tree Inventory Application for City of East Jakarta","Trees are essential elements of an urban space. The presence of trees in urban areas is not only appreciated as physical attribute, but beyond this, it serves a fundamental function in balancing and conserving urban ecosystem. Especially in tropical countries like Indonesia which receive high levels of solar radiation, trees contribute to the protection of urban areas from the impact of excessive micro-climatic conditions. But, the presence of trees sometimes resulted in the accidents for the residences because of broken branches and human injuries. This situation leads the city to prepare a tree inventory system, which is beneficial in giving the information about tree conditions and thus the information that would be useful for tree maintenance activities. The tree inventory on application for the city of East Jakarta was built for this purpose, comprising a tree inventory and easy access to the database. The application connects the database source with the GIS map, so that the users could retrieve information for each kind of data.",1,https://api.osf.io/v2/files/5d072cc97b8c4d00199f82b9/,177,https://engrxiv.org/a5d3z/,10.31224/osf.io/a5d3z,,2019-06-17T13:10:33.799010,2019-06-17T13:13:01.273291 | |
| u78t9,"Preparation of Sand Beds Using Fluidization","Reconstituting soil beds to a desired density is essential to geotechnical modeling tests. In this study, we apply and assess the method of air fluidization to prepare sand beds for geotechnical engineering studies. Through it, an automated bed preparation process can be realized. The details of device structure and design are presented as a reference for application of the methodology. By quantifying the average and local post-fluidization density of the bed, the performance of the fluidized bed device is characterized. With the addition of vibration and by changing the defluidization rate, the sand can be prepared with volume-based relative densities ranging from 10% to 92%. Local sand density, measured with a cone penetrometer, is nearly uniform across the bed: density variation is less than 13% (coefficient of variation with respect to relative density) for all protocols except for some beds prepared by defluidization only. The variation of local density and penetration resistance measured across the bed breadth is comparable to results from beds prepared by the commonly used method of pluviation. This suggests that sand beds reconstituted using air fluidization are suitable for geotechnical modeling tests.",1,https://api.osf.io/v2/files/5d040187e2124b0017396a68/,391,https://engrxiv.org/u78t9/,10.31224/osf.io/u78t9,,2019-06-14T20:37:47.955151,2019-06-14T20:38:27.097140 | |
| vngzq,"Reliability versus Renewables: Modeling Decision Making in CAISO and PJM to Identify Market Barriers and Supports to Renewable Energy Adoption in the US","While electrification has been proposed as a key mechanism for combating global warming, in the US, fossil fuels are still the mainstay of the electricity sector. This work seeks to identify market barriers and supports for the adoption of renewable energy. A framework to represent the evaluation process for generating capacity is proposed and applied to two regions: California (CAISO), where legislation requires most electricity to be supplied by renewables by 2030, and the Mid-Atlantic (PJM), where renewables have barely penetrated the market. Generation technologies are ordered via multiobjective optimization using genetic algorithms to resolve a bounded knapsack problem. Price factors for each technology are established. A net present value is assessed for representative projects in each region and technology. Local sensitivity analysis is performed. Results suggest that capacity payments in PJM offer an incentive to fossil-fuel based plants, which calls into question the suitability of carbon pricing in the region. While solar PV has the lowest costs, profitability was highest for natural gas based plants in PJM. Sensitivity is higher in CAISO than in PJM due to lower profit margins. Renewables were selected most frequently in the cost optimization, with natural gas present in ~10% of results.",1,https://api.osf.io/v2/files/5d03e3657b8c4d00189c179e/,245,https://engrxiv.org/vngzq/,10.31224/osf.io/vngzq,,2019-06-14T18:53:19.142658,2019-06-14T18:53:47.251292 | |
| 3mpyt,"Application of background pressure with kinematic criterion for free surface extension to suppress non-physical voids in the finite volume particle method","Lagrangian particle methods such as smoothed particle hydrodynamics (SPH) and the finite volume particle method (FVPM) can suffer from non-physical voids in the spatial discretisation, due to the inability of numerical particles to deform as continuum fluid elements can. It is known that the situation can be improved for wall-bounded flows in SPH by adding a uniform background pressure to ensure positive absolute pressure everywhere. In this article, we investigate the application of background pressure in FVPM, and show that numerical voids grow under negative pressure and collapse under positive pressure. To use this technique in free-surface flow, however, the background pressure must be applied as an atmospheric pressure at the free surface. A kinematic criterion for free surface extension (KCFSE) to differentiate physical free surfaces from new numerical voids has been developed, supplementing the inherent capability of FVPM to identify free-surface particles robustly. The novel method enables background pressure to be applied at physical free surfaces and throughout the fluid, but not in non-physical voids, facilitating the suppression of such spurious voids. The KCFSE is validated for a translating square cylinder inside a rectangular numerical domain, with and without a free surface, and liquid in an oscillating rectangular tank.",1,https://api.osf.io/v2/files/5d026121760f11001afbd862/,195,https://engrxiv.org/3mpyt/,10.31224/osf.io/3mpyt,10.1016/j.enganabound.2019.05.010,2019-06-13T17:56:22.461458,2019-06-13T17:56:48.954686 | |
| wekmq,"Design and Repeatability Analysis of Desktop Tool for Rapid Pre-Cracking of Notched Ductile Plastic Fracture Specimens","Fracture testing is a useful mechanical testing process to explore the properties and behavior of materials, one that has seen much development and refinement in recent decades. One of the most important steps in preparing samples for testing is the production of a sharp pre-crack to initiate crack propagation in a predictable way. While several methods have been developed for doing this, particularly for metals and brittle plastic materials, a quick and reliable method for more ductile materials is lacking. This technical note describes the design and verification of a simple desktop-sized pre-cracking device which safely uses a razor blade and hammer to quickly produce straight and sharp pre-cracks of consistent depth in ductile polymeric material samples. To verify its capability and consistency, a series of tests were performed using both molded and 3-D printed acrylonitrile butadiene styrene (ABS). First, a series of 40 notched 25 mm x 9.5 mm ABS bars were pre-cracked, and the distance under the crack measured on both sides of the bar. Several bars were then broken along the cracks to examine the quality of the pre-crack front. These tests were then repeated 20 times each for two print orientations of fused deposition modeling (FDM) ABS printed at 100% density. All 80 pre-cracks were found to be straight, sharp, and within 1% of the nominal distance under the crack for all samples. The consistency of the pre-cracks throughout the sample cross-section was also observed to be excellent, with all 80 tests showing less than 0.25 mm of deviation, even on the highly-anisotropic FDM samples.",1,https://api.osf.io/v2/files/5d00a34a2a575b0017a08c38/,242,https://engrxiv.org/wekmq/,10.31224/osf.io/wekmq,,2019-06-12T21:20:12.253037,2019-06-12T21:20:41.637028 | |
| 85btc,"Dynamic traffic assignment with a node-based cell transmission model satisfying the link-level first-in-first-out principle","This paper develops node-based formulations for user equilibrium (UE) and system optimum (SO) dynamic traffic assignment (DTA) problems with departure time choice and route choices for general multiple origin-destination networks. Both the formulations are embedded with a new cell transmission model that satisfies the link-level First-In-First-Out (FIFO) principle. Because the formulations are node-based, the need for path enumeration is obviated, which results in considerable computational efficiency compared to the existing path-based models. While this advantage of node-based (or bush-based) models has been widely accepted in the literature of static traffic assignment, the formulations of dynamic traffic assignment models have mostly been path-based. The present work first describes a node-based cell transmission model that satisfies the link-level FIFO principle, which is fit within a DTA framework that facilitates efficient computation of UE and SO solutions. Further contributions of the work include the introduction of a backpropagation algorithm to efficiently compute marginal costs and complementarity formulations of the problems. Finally, numerical results are presented to demonstrate the performance of the proposed models using two standard test networks, along with a discussion of their convergence.",1,https://api.osf.io/v2/files/5d009249edaf2800199dd9fc/,171,https://engrxiv.org/85btc/,10.31224/osf.io/85btc,,2019-06-12T21:18:10.482875,2019-08-23T02:28:38.830308 | |
| bv6g4,"Sulfide and Fluoride Ions Based Passivation of GaAs(100) Surface and Concept of Combining Surface Passivation with Tunnel Junction Based Molecular Devices","Sulfur interaction with GaAs can reduce the harmful effect of surface states on recombination attributes. Apart from surface passivation, study of sulfur bonding on GaAs is also important for developing novel molecular electronics and molecular spintronics devices, where a molecular channel can be connected to at least one GaAs surface via thiol functional group. Excess thiol functional groups that are not involved in making molecular device channels can serve as the passivants to quench surface states. However, the primary challenge lies in increasing the stability and effectiveness of the sulfur passivated GaAs. We have investigated the effect of single and double step surface passivation of n-GaAs(100) by using the sulfide and fluoride ions. Our single-step passivation involved the use of sulfide and fluoride ions individually. However, the two kinds of double-step passivations were performed by treating the n-GaAs surface. In the first approach GaAs surface was firstly treated with sulfide ions and secondly with fluoride ions, respectively. In the second double step approach GaAs surface was first treated with fluoride ions followed by sulfide ions, respectively. Sulfidation was conducted using the nonaqueous solution of sodium sulfide salt. Whereas the passivation steps with fluoride ion was performed with the aqueous solution of ammonium fluoride. Both sulfidation and fluoridation steps were performed either by dipping the GaAs sample in the desired ionic solution or electrochemically. Photoluminescence was conducted to characterize the relative changes in surface recombination velocity due to the single and double step surface passivation. Photoluminescence study showed that the double-step chemical treatment where GaAs was first treated with fluoride ions followed by the sulfide ions yielded the highest improvement. The time vs. photoluminescence study showed that this double-step passivation exhibited lower degradation rate as compared to widely discussed sulfide ion passivated GaAs surface. We also conducted surface elemental analysis using Rutherford Back Scattering to decipher the near surface chemical changes due to the four passivation methodologies we adopted. The double-step passivations affected the shallower region near GaAs surface as compared to the single step passivations.",1,https://api.osf.io/v2/files/5d0053392a575b00169f8172/,212,https://engrxiv.org/bv6g4/,10.31224/osf.io/bv6g4,10.1557/adv.2017.380,2019-06-12T02:45:21.861469,2019-06-12T02:45:41.331085 | |
| ztj9k,"Decision Fusion of EEG and fNIRS Signals","In this study, we investigated the use of multimodal functional neuroimaging in detecting mental stress on the prefrontal cortex (PFC). We recorded Electroencephalography (EEG) and functional Near Infrared Spectroscopy (fNIRS) simultaneously from 20-subjects performing mental arithmetic task under control and stress conditions. Stress was induced in this study based on two established stressors – time pressure and negative feedback about peer performance. We explored decision fusion by using support vector machine classifier for each modality, and optimizing the classifiers based on Receiver Operating Characteristic (ROC) curve values. Experiment results revealed significant reduction in alpha rhythm and mean change in concentration of oxygenated hemoglobin at PFC when stressed, p<0.001 and 0.0001 respectively. The decision fusion improved significantly the detection rate of mental stress by +7.76% and +10.57%, when compared to sole modality of EEG and fNIRS, respectively.",1,https://api.osf.io/v2/files/5cffa33a2a575b00179f7190/,288,https://engrxiv.org/ztj9k/,10.31224/osf.io/ztj9k,,2019-06-11T13:02:18.702988,2019-06-11T13:02:41.914128 | |
| hsevm,"On some sufficient conditions for distributed QoS support in wireless networks","Given a wireless network where some pairs of communication links interfere with each other, we study sufficient conditions for determining whether a given set of minimum bandwidth Quality of Service (QoS) requirements can be satisfied. We are especially interested in distributed implementations which have low communication overhead and low processing complexity. Row constraints are known to be sufficient, and we introduce the notion of the induced star number of a graph and show that this quantity determines the performance of this condition. We further investigate this problem for some special classes of networks and interference models such as unit disk networks and primary interference constraints. We determine the exact worst-case performance of some distributed algorithms for admission control and thereby show that they can be arbitrarily far away from optimal; we then show that these algorithms are within a bounded factor away from optimal for some well known classes of networks and interference models.",1,https://api.osf.io/v2/files/5cff51d5fea9230017806c4a/,198,https://engrxiv.org/hsevm/,10.31224/osf.io/hsevm,,2019-06-11T11:46:26.518812,2019-06-11T11:46:48.089492 | |
| dqzm7,"Adaptive Special Strategies Resampling for Inertial-based Mobile Indoor Positioning Systems : An Initial Proposal","The phenomenon of sample impoverishment during particle filtering always contribute computation burden to the inertial-based mobile IPS systems. This is due to the factor of noise measurement and number of particle. Usually, the special strategies resampling algorithms was used. However, these algorithms just can fit in certain environment. This needs an adaptation of noise measurement and number of particle in a algorithm in order to make resampling with more intelligence, reliability and robust. In tbis paper, we will propose an adaptive special strategies resampling by adapting noise and particle measurement. These adaptation is used to determine the most suitable algorithm of special strategies resampling, that can be switched for resampling purpose. Finally, we illustrate our proposed solution our for indoor environment setup.",1,https://api.osf.io/v2/files/5cfef75cedaf28001a9d090d/,224,https://engrxiv.org/dqzm7/,10.31224/osf.io/dqzm7,,2019-06-11T11:44:41.056708,2019-06-12T00:34:12.660780 | |
| f3ytz,"Adaptive Navigation Support: A Literature Review of Its Application and Implication in Learning Process","The use of technology has been widely used for many people in every aspect of life and become part of daily activities in recent years. One of technology application is in the learning and education process. Adaptive Navigation Support (ANS) is a method and part of a hypermedia study that can boost the performance of students by using the benefit of technology. With ANS, students are able to make the learning process more interesting as the learning material relatively corresponds to their knowledge and preferences. Furthermore, ANS can guide students in finding their paths and ways in hyperspace based on student requirements, goals, and characteristics. Therefore, ANS has caught many researchers attention in their studies to improve student skills and performance in the learning process. Many papers, discussed in ANS, have been published over the last decade, however, no one has studied the ANS in a comprehensive way. This paper is a literature review in ANS and its application as well as its implication in the learning process. There are fourty-nine papers as its source of analysis. Our findings show that the applications of ANS can be classified into four dimensions, such as platform, use case, impact, and process. These classifications are based on the study of ANS applications and implications over the last decade.",1,https://api.osf.io/v2/files/5cfce72a89c9830018be3426/,243,https://engrxiv.org/f3ytz/,10.31224/osf.io/f3ytz,10.3991/ijet.v14i16.10719,2019-06-10T13:14:27.781265,2019-10-04T03:00:59.699816 | |
| 7s5qu,"Detailed Balance Analysis of Photovoltaic Windows","There are a number of technical and socio-economic factors converging to position photovoltaic (PV) windows as a transformative technology for the energy landscape of the future: 1) Urban areas currently account for 67–76% of global final energy consumption. 2) 70% of the world’s population will live in urban areas by 2050. 3) The overwhelming architectural trend is away from opaque building components and toward all-glass facades. 4) Photovoltaics are becoming extremely affordable, and the most expensive components in a conventional module are the glass and transparent metals—components that are already in highly-insulating glazing. 5) Buildings are increasingly built to easily integrate with photovoltaic energy generation using DC microgrids and on-site energy generation to balance high demand on the grid. Rational design of PV windows is of paramount importance to realize their impact. In this work, we provide an analysis on the theoretical performance of PV windows using a detailed balance model to understand the complex design space of power conversion efficiency, visible light transmittance, solar heat gain coefficient, and color. We find there are two distinct regimes for PV window absorber design. The first lowvisible light transmittance regime validates the most prevalent approach to semitransparent PV windows in which conventional absorber materials (Si, CIGS, CdTe, CZTS, perovskite, etc.) are thinned to allow visible light to pass through. In this thinned-absorber regime, an ideal bandgap of ~1.35 eV maximizes performance, which is consistent with the famous Shockley–Queisser limit. However, we identify a second, high visible light transmittance regime in which the ideal bandgap for maximum power conversion efficiency increases monotonically from 2 to 3 eV with increasing visible light transmittance. In this tuned-bandgap regime, the solar cell exhibits lower losses and tunable solar heat gain and color.",1,https://api.osf.io/v2/files/5cf9644d8c451d0018ea1e5c/,261,https://engrxiv.org/7s5qu/,10.31224/osf.io/7s5qu,10.1021/acsenergylett.9b01316,2019-06-06T21:20:21.966377,2019-09-05T01:53:05.296252 | |
| fq8ze,"Data Prognostics Using Symbolic Regression","This paper describes a general technique for data prognostics using symbolic regression. This analysis treats the characterization of turbofan engine degradation as a particular application for the general technique. The proposed genetic program (GP) characterizes engine degradation, and then uses that characterization to both detect engine faults and predict the remaining lifetimes of engines after a fault. The genetic program exploits the fact that engine degradation manifests itself as changing correlations between sensor outputs. The NASA Prognostics Data Repository provides a training set in which 100 simulated engines are run to failure, and a test set in which a separate set of 100 simulated engines are shut off before they fail. The GP uses the training fleet of engines to identify the sensor relationships that indicate engine fault and predict remaining lifetime, and then observes the learned sensor relationships in the test fleet. The genetic program successfully detects the moment that the fault occurs for every engine in the test fleet and accurately predicts the remaining lifetime of the engines after the fault.",1,https://api.osf.io/v2/files/5cf9218b3a4d9500178ae2f4/,247,https://engrxiv.org/fq8ze/,10.31224/osf.io/fq8ze,,2019-06-06T15:35:08.395890,2019-06-06T15:35:27.731446 | |
| fwrqj,"An Analysis of Design Process and Performance in Distributed Data Science Teams","Purpose – Often, it is assumed that teams are better at solving problems than individuals working independently. However, recent work in engineering, design, and psychology contradicts this assumption. This work examines the behavior of teams engaged in data science competitions. Crowdsourced competitions have seen increased used for software development and data science, and platforms often encourage teamwork between participants. | |
| Design/methodology/approach – We specifically examine teams participating in data science competitions hosted by Kaggle. We analyze data provided by Kaggle to compare the effect of team size and interaction frequency on team performance. We also contextualize these results through a semantic analysis. | |
| Findings – This work demonstrates that groups of individuals working independently may outperform interacting teams on average, but that small, interacting teams are more likely to win competitions. The semantic analysis revealed differences in forum participation, verb usage, and pronoun usage when comparing top- and bottom-performing teams. | |
| Research limitations/implications- These results reveal a perplexing tension that must be explored further: true teams may experience better performance with higher cohesion, but nominal teams may perform even better on average with essentially no cohesion. A limitation of this research includes not factoring in team member experience level and reliance on extant data. | |
| Originality/Value – These results are potentially of use to designers of crowdsourced data science competitions as well as managers and contributors to distributed software development projects.",1,https://api.osf.io/v2/files/5cf7a23ed4c7d700173d3efe/,246,https://engrxiv.org/fwrqj/,10.31224/osf.io/fwrqj,,2019-06-05T12:50:12.374059,2019-06-05T12:50:26.611294 | |
| sev3c,"Bond-based peridynamics: A tale of two Poisson's ratios","This paper explores the restrictions imposed by bond-based peridynamics, particularly with respect to plane strain and plane stress models. We begin with a review of the derivations in [2] wherein for isotropic materials a Poisson's ratio restriction of 1/4 for plane strain and 1/3 for plane stress is deduced. Next, we show Cauchy's relations are an intrinsic limitation of bond-based peridynamics and specialize this result to plane strain and plane stress models, generalizing the results of [2] and demonstrating the Poisson's ratio restrictions in [2] are simply a consequence of Cauchy's relations. We conclude with a discussion of the validity of peridynamic plane strain and plane stress models formulated from two-dimensional bond-based peridynamic models.",1,https://api.osf.io/v2/files/5cf683ced987b50017899f7c/,387,https://engrxiv.org/sev3c/,10.31224/osf.io/sev3c,,2019-06-04T15:48:36.549264,2019-06-04T16:44:30.318775 | |
| kjhbx,"Conceptual design of a rotational mechanical time base with varying inertia","Flexure pivot oscillators have the potential to advantageously replace the traditional balance wheel-spiral spring oscillator used in mechanical watches due to their significantly lower friction. However, they have inherent nonlinear elastic properties that can introduce a variation of their frequency with amplitude called isochronism defect. Previous research has focused on controlling the elastic behavior of flexure pivot oscillators to reach isochronism. We present a new way of minimizing the isochronism defect of rotational oscillators by varying their inertia. This principle is embodied in a new family of oscillators we call rotation-dilation coupled oscillator (RDCO). Their architecture also presents a rotational symmetry that is advantageous for minimizing the effects of gravity on their period. We present a description of this new oscillator family, give conceptual tools for tuning its isochronism and show examples of physical implementations.",1,https://api.osf.io/v2/files/5cf68075096624001ad8ea13/,284,https://engrxiv.org/kjhbx/,10.31224/osf.io/kjhbx,,2019-06-04T15:47:43.039351,2019-06-04T16:43:44.061923 | |
| u48bc,"Modelling Gene-Protein-Reaction Associations on an FPGA","Genome-Scale metabolic models have proven to be incredibly useful.Allowing researchers to model cellular functionality based upon gene expression. However as the number of genes and reactions increases it can become computationally demanding. The first step in genome-scale metabolic modelling is to model the relationship between genes and reactions in the form of Gene-Protein-Reaction Associations (GPRA). In this research we have developed a way to model GPRAs on an Altera Cyclone II FPGA using Quartus II programmable logic device design software and the VHDL hardware description language. The model consisting of 7 genes and 7 reactions was implemented using 7 combinational functions and 14 I/O pins. This model will be the first step towards creating a full genome scale metabolic model on FPGA devices which we will be fully investigating in future studies.",1,https://api.osf.io/v2/files/5cf52d0f6677ac001cf30918/,240,https://engrxiv.org/u48bc/,10.31224/osf.io/u48bc,,2019-06-03T16:28:15.617277,2019-06-03T16:33:01.445717 | |
| 48wr2,"Optimal composition of tasks in cloud manufacturing platform: a novel hybrid GWO-GA approach","Emerging cloud manufacturing paradigm aims towards providing highly integrated solutions via enabling cooperation between distributed manufacturing resources and capabilities. Implementation of this groundbreaking idea, however, is facing serious challenges springing from the currently centralized industrial structures. In order to help it make its way out, researchers have to address a number of pivotal issues in this regard. Service composition and optimal selection (SCOS), which tackles the problem of optimally selecting and combining available resources into a composite service is one of them. To deal with this NP-hard problem, we developed a novel hybrid algorithm based on the recentlyintroduced grey wolf optimizer (GWO) in which evolutionary operators are also embedded into the hunting mechanism of the basic algorithm. | |
| This approach not only makes it possible to adapt an algorithm with continuous structure such as GWO to solve a combinatorial problem such as SCOS, but also empowers it with providing higher exploration through crossover and mutation operators. Experiments conducted clearly proves the superior performance of the proposed algorithm over existing discrete variations of GWO and genetic algorithm, especially in large-scale SCOS problems.",1,https://api.osf.io/v2/files/5cf48cd42a50c40019847628/,327,https://engrxiv.org/48wr2/,10.31224/osf.io/48wr2,,2019-06-03T12:43:18.205773,2019-06-05T20:49:34.151397 | |
| ehaux,"Issues of Privilege in University Service-Learning","Service-learning activities, such as development projects organized under the Engineers Without Borders USA organization, are popular on many university campuses as a mechanism for providing applied, global learning experiences for both engineering and non-engineering students. Existing studies have found that these experiences are meaningful for students and help them to apply what they learn in the classroom to the “real world” while learning valuable teamwork, communication, project management, and other skills. In this paper, we report on our ongoing research about EWB-USA participation and outcomes and, using case studies from our ethnographic research, discuss barriers to EWB-USA project participation among less privileged students. The implications this issue has for institutions interested in using service-learning to meet core learning outcomes as well as the need to diversify service-learning will be considered.",1,https://api.osf.io/v2/files/5cf285e723fec40017f20150/,178,https://engrxiv.org/ehaux/,10.31224/osf.io/ehaux,,2019-06-01T14:10:01.936562,2019-09-09T01:05:19.310825 | |
| f28zk,"Nonlinear numerical simulation of punching shear behaviour of reinforced concrete flat slabs with shear-heads","This paper examines the structural response of reinforced concrete flat slabs, provided with fully-embedded shear-heads, through detailed three-dimensional nonlinear numerical simulations and parametric assessments using concrete damage plasticity models. Validations of the adopted nonlinear finite element procedures are carried out against experimental results from three test series. After gaining confidence in the ability of the numerical models to predict closely the full inelastic response and failure modes, numerical investigations are carried out in order to examine the influence of key material and geometric parameters. The results of these numerical assessments enable the identification of three modes of failure as a function of the interaction between the shear-head and surrounding concrete. Based on the findings, coupled with results from previous studies, analytical models are proposed for predicting the rotational response as well as the ultimate strength of such slab systems. Practical recommendations are also provided for the design of shear-heads in RC slabs, including the embedment length and section size. The analytical expressions proposed in this paper, based on a wide-ranging parametric assessment, are shown to offer a more reliable design approach in comparison with existing methods for all types of shear-heads, and are suitable for direct practical application.",1,https://api.osf.io/v2/files/5cef9bb18d6e050018673279/,374,https://engrxiv.org/f28zk/,10.31224/osf.io/f28zk,,2019-05-30T18:27:36.952554,2019-05-30T18:28:06.450436 | |
| 45cf9,"Results from a water-saving maintenance campaign at Cape Town schools in the run-up to Day Zero","Many South African schools struggle to maintain their water systems, particularly in the water-constrained Western Cape province, where the so-called ""Day Zero'' drought had intensified the urgency of saving water and increased the cost of supply. The problem is compounded by insufficient governmental funding, the lack of well-structured government policies, and a shortage of skilled maintenance staff at the schools. We evaluate the impact of a plumbing maintenance drive at 196 schools at the apex of the drought. Hypothesising that even the most basic maintenance could be a huge financial help to these schools, we gave plumbers a list of typical easy-gain repairs and restricted the budget to R5,000 per school, with some ad hoc exceptions. We then analysed the cost and benefit of these repairs, using data on the minimum night flow as recorded by smart water meters. We found an average of 28% reduction in MNF within five days of the reported maintenance date. The once-off R1,22 million spent on the 196 schools resulted in a monthly saving of R1,90 million -- a saving that the schools could put to academic purposes.",1,https://api.osf.io/v2/files/5cef40f835f2580016b2af3f/,452,https://engrxiv.org/45cf9/,10.31224/osf.io/45cf9,10.1016/j.scs.2019.101639,2019-05-30T18:25:43.534022,2019-07-01T13:22:54.075415 | |
| u3fnb,"A BioHackathon on the challenges of aging: Rapid need-finding and solution modeling in a student-led event","The Biointerfaces Interlaboratory Committees, the student organization for the Biointerfaces Institute at the University of Michigan, organized and executed an 8 hour “BioHackathon” on the broadly defined clinical topic of ‘Aging.’ The event began with experts in the field (a clinician and an engineer) highlighting the areas of greatest need in which engineers could improve the lives of the aging population. Attendees separated into teams based on shared interests in pursuing specific needs, and rapidly developed need statements and solution models to help the elderly. Solutions ranged from a smart toothbrush to help detect pneumonia in early stages, to small clothing pads to help reduce the impact of falls on hip fractures. Based on a follow-up anonymous internet survey, the attendees indicated they enjoyed the event, and would likely attend a similar event in the future. We conclude by reflecting upon the event, and suggest ways in which we could improve the style of the event for future hackathons.",1,https://api.osf.io/v2/files/5cef3a7d8d6e05001962e1a6/,257,https://engrxiv.org/u3fnb/,10.31224/osf.io/u3fnb,,2019-05-30T18:25:03.556443,2019-05-30T18:25:21.234500 | |
| v6ams,"Chalk, talk, and energy efficiency: Saving electricity at South African schools through staff training and smart meter data visualisation","South African schools are finding electricity costly in terms of money that could be spent on the primary purpose of educating children, but they tend not to be proactive about these costs. Managing the monthly bills is a huge task: the usage numbers on the bill are incomprehensible, the time-of-use tariff structure is bewilderingly complex, and the person who deals with payments is usually an overburdened teacher. This paper describes a controlled behavioural experiment carried out at five schools in Stellenbosch. We provided highly visualised and intuitive daily, weekly and monthly reports to three of the schools, the other two acting as controls. The reports were shared with teachers, principals and the governing body to encourage accountability. Usage was shown as a colour-coded energy and financial component per hour and per tariff class. Using the difference-in-differences method, we found financial savings of 11% and 14% at two of the schools and 13% at the third school, where staff were also trained on the tariff structure before reporting started. These results suggest that sharing high-frequency, digestible information could help South African schools reduce their energy bills; a saving that has particular relevance given the country’s dependence on fossil fuels.",1,https://api.osf.io/v2/files/5cef28ec2a50c400167fa791/,260,https://engrxiv.org/v6ams/,10.31224/osf.io/v6ams,10.1016/j.erss.2019.05.022,2019-05-30T18:23:15.869753,2019-06-19T19:06:36.180792 | |
| za2p9,"Vegetation High-Impedance Faults' High-Frequency Signatures via Sparse Coding","The behavior of High-Impedance Faults (HIFs) in power distribution systems depends on multiple factors, making it a challenging disturbance to model. If enough data from real staged faults is provided, signal processing techniques can help reveal patterns from a specific type of fault. Such a task is implemented herein by employing the Shift-Invariant Sparse Coding (SISC) technique on a data set of staged vegetation high-impedance faults. The technique facilitates the uncoupling of shifted and convoluted patterns present in the recorded signals from fault tests. The deconvolution of these patterns was then individually studied to identify the possible repeating fault signatures. The work is primarily focused on the investigation of the under-discussed high-frequency faults signals, especially regarding voltage disturbances created by the fault currents. Therefore, the main contribution from this paper is the resulted evidence of consistent behavior from real vegetation HIFs at higher frequencies. These results can enhance phenomena awareness and support future methodologies dealing with these disturbances.",1,https://api.osf.io/v2/files/5cee0b2b35f2580017ac2b06/,225,https://engrxiv.org/za2p9/,10.31224/osf.io/za2p9,,2019-05-29T12:57:39.809137,2019-05-29T12:58:03.956517 | |
| v5btz,"Rational Design of Ion Separation Membranes","Synthetic membranes for desalination and ion separation processes are a prerequisite for the supply of safe and sufficient drinking water as well as smart process water tailored to its application. This requires a versatile membrane fabrication methodology. Starting from an extensive set of new ion separation membranes synthesized with a layer-by-layer methodology, we demonstrate for the first time that an artificial neural network (ANN) can predict ion retention and water flux values based on membrane fabrication conditions. The predictive ANN is used in a local single-objective optimization approach to identify manufacturing conditions that improve permeability of existing membranes. A deterministic global multi-objective optimization is performed in order to identify the upper bound (Pareto front) of the delicate trade-off between ion retention characteristics and permeability. Ultimately, a coupling of the ANN into a hybrid model enables physical insight into the influence of fabrication conditions on apparent membrane properties.",1,https://api.osf.io/v2/files/5cebcd858d6e05001a5f457d/,293,https://engrxiv.org/v5btz/,10.31224/osf.io/v5btz,10.1016/j.memsci.2018.10.013,2019-05-27T16:46:32.341028,2019-05-27T16:46:47.401218 | |
| 5tg8e,"Shell and lumen side flow and pressure communication during permeation and filtration in a multibore polymer membrane module","This study reveals the importance of the module geometry on the flow field and pressure distribution during membrane permeation for multibore membranes. The pathways of permeation are unraveled within a custom-made multibore single membrane module. For this, we combine flow velocimetry of magnetic resonance imaging (flow-MRI) with computational fluid dynamic (CFD) simulations and permeation experiments. First, a systematic simulation study identifies flow patterns based on simplified geometrical features that are supported experimentally through flow-MRI measurements. This comprehensive study shows how small geometric deviations from the idealistic assumptions result in unexpected fluid flow on the shell and lumen side in the module. Second, the influence of those non-ideal flow patterns during the filtration of silica particles are revealed by MRI. The results indicate heterogeneous silica deposition due to geometry induced flow fields. Contrary to the idealized assumption, the subsequent backwashing is also influenced by those deposition patterns. Hence, unavoidable non-idealities of membrane positioning during the construction of the module influence the performance of the membrane filtration. With this study, we stimulate to analyze and pioneer new strategies to optimize module design and fully recover the membrane's performance after filtration cycles during backwashing. Even more, extensive future studies on multiple multibore membranes can reveal their mutual interaction closing the gap between the single multibore membrane behavior and multibore membrane module properties.",1,https://api.osf.io/v2/files/5cebc8f78d6e05001960cdab/,148,https://engrxiv.org/5tg8e/,10.31224/osf.io/5tg8e,10.1016/j.memsci.2019.04.070,2019-05-27T16:45:48.469362,2019-05-27T16:46:07.232928 | |
| 6n53p,"Closing the cycle: phosphorus removal and recovery from diluted e?uents using acid resistive membranes","New regulations in many developed countries call for significant reduction in phosphorus concentration for effluents released to the environment. At the same time, recovery of phosphorus – a non-renewable resource used mainly as fertilizer – from anthropogenic waste is extensively studied and bolstered as a crucial component in maintaining future food security. Thus far, studies on phosphorus recovery mainly focused on concentrated streams; although diluted effluents such as treated wastewater often contain a significant portion of the phosphorus mass. Here we propose a new approach for the simultaneous removal and recovery of phosphorus from diluted effluents using a membrane characterized by high phosphate rejection and acid resistance. High P rejection allows for the concentration of phosphorus in the retentate until recoverable calcium-phosphate precipitants are formed, while acid resistance enables a simple and effective chemical cleaning of the membrane. Factors affecting the removal and recovery of phosphorus during filtration are studied here experimentally and through thermochemical modeling. CaCO3 precipitation in the retentate resulted in severe scaling, whereas calcium-phosphate precipitated mostly in the bulk, resulting in colloidal fouling which was manageable by maintaining sub-critical permeate flux. Selective Ca-P precipitation is feasible via pH adjustments, requiring very little acid addition as shown through thermochemical modeling. Calcium-phosphate deposits were easily removed from the feed channel using acid-cleaning, and the permeate flux was completely restored. Furthermore, phosphorus removal and recovery by nanofiltration was shown to require less operating expenses compared to a more conventional approach comprising P removal by ferric chloride addition and its subsequent recovery from incinerated sludge. Our results therefore demonstrate the potential of this new approach as a step forward towards closing the anthropogenic phosphorus cycle.",1,https://api.osf.io/v2/files/5cebc73a23fec40018e6b2a8/,274,https://engrxiv.org/6n53p/,10.31224/osf.io/6n53p,10.1016/j.cej.2018.03.181,2019-05-27T16:44:15.733228,2019-05-27T16:44:47.580370 | |
| jq7u9,"2D Patterned Ion-Exhange Membranes Induce Electroconvection","Concentration polarization is a diffusion‐limited phenomenon for ion transport in electrodialysis based desalination processes. Once a so‐called limiting current is reached, the resistance of the system rises notably manifested as a plateau region in the current–voltage curves. For long it is hypothesized that altering the surface properties of the membrane can overcome the diffusional transport limitation by the induction of electroconvective vortices mixing the laminar boundary layer. To systematically investigate the influence of geometrical and chemical membrane surface topology on the evolution of electroconvection, circular patterns of polystyrene, poly(2‐vinylpyridine) (P2VP), and P2VP microgels are inkjet printed on cation‐exchange membranes. All types of patterns cause an insignificant increase in membrane resistance but they reduce the plateau lengths indicating the desired accelerated onset of electroconvection. In case of polystyrene (PS) patterns, the drop in plateau length results in a small reduction in transport resistance for overlimiting currents. However, membranes modified with linear P2VP and P2VP microgel patterns do exhibit a significantly decreased resistance in this region at a simultaneous increase of the limiting current density. Direct numerical simulations support the interpretation that the surface charge of the printed patterns influences the direction of the vortices being advantageous during ion transport toward the membrane.",1,https://api.osf.io/v2/files/5cebc6992a50c400167deda5/,287,https://engrxiv.org/jq7u9/,10.31224/osf.io/jq7u9,10.1002/admi.201801309,2019-05-27T16:39:47.729125,2019-05-27T16:40:13.672920 | |
| 5jyte,"Unraveling charge transport in carbon ow-electrodes: performance prediction for desalination applications","We report the design and analysis of a salt metathesis process using Flow-Electrode Capacitive Deionization (FCDI) for the generation of a concentrated valuable magnesium sulfate solution from dilute MgCl2 and Na2SO4 (or K2SO4) solutions. First, a batch mode decomposition and recombination of the MgCl2, Na2SO4, and K2SO4 solutions was studied with varying initial concentrations. Current efficiencies of ∼100% were observed for each cycle. In a so-called decomposition step, two different salt solutions are decomposed into electrically charged slurries having the counterions adsorbed. Swapping the slurries with the stored counterions during the recombination step results into new salt solutions upon discharge including the desired product. Both, purity of products and overall conversion of ions into the products, depend on operational parameters, while maximal achieved MgSO4 purity was as high as 93% with a concentration factor of 6.3 and a discharge current efficiency of ∼85%. Finally, a semicontinuous FCDI metathesis system was investigated. Performing the recombination step at appropriate process conditions also allows the concentration of the resulting product solutions by a factor as high as 81.5 with MgSO4 purity of ∼80% and current efficiencies of 96%. Future improvements in process configurations and membrane ion selectivity will render the process even more selective.",1,https://api.osf.io/v2/files/5cebc5ce35f2580017aade24/,324,https://engrxiv.org/5jyte/,10.31224/osf.io/5jyte,10.1021/acssuschemeng.6b03086,2019-05-27T16:38:37.539932,2019-05-27T16:39:08.135922 | |
| m9472,"On charge percolation in slurry electrodes used in Vanadium Redox Flow Batteries","In vanadium redox flow battery systems porous carbon felts are commonly employed as electrodes inside the flow channel. Recently, slurry electrodes (or flow suspension electrodes) were introduced as a potentially viable electrode system. Such electrode systems are little understood so far. Mass, momentum and charge transfer phenomena co-occur, interactions with each other are nearly impossible to capture experimentally. We present a novel discrete model of the particulate phase combining theories from fluid dynamics, colloidal physics, and electrochemistry with a coupled CFD-DEM approach. The methodology allows to visualize local phenomena occurring during the charging of the battery and to compute the net current of the slurry electrode system. We demonstrate that an increasing particle volume fraction enables the formation of conducting networks in the flow electrode until a threshold is reached. Our study concludes, that the assumption of all particles participating in the charge transfer as assumed in pure CFD investigations is not necessarily valid.",1,https://api.osf.io/v2/files/5cebc52b2a50c4001782b7dd/,271,https://engrxiv.org/m9472/,10.31224/osf.io/m9472,10.1016/j.elecom.2019.02.013,2019-05-27T16:37:29.031874,2019-05-27T16:37:51.899916 | |
| dmpr3,"3D Nanofabrication inside rapid prototyped microfluidic channels showcased by wet-spinning of single micrometre fibres","Microfluidics is an established multidisciplinary research domain with widespread applications in the fields of medicine, biotechnology and engineering. Conventional production methods of microfluidic chips have been limited to planar structures, preventing the exploitation of truly three-dimensional architectures for applications such as multi-phase droplet preparation or wet-phase fibre spinning. Here the challenge of nanofabrication inside a microfluidic chip is tackled for the showcase of a spider-inspired spinneret. Multiphoton lithography, an additive manufacturing method, was used to produce free-form microfluidic masters, subsequently replicated by soft lithography. Into the resulting microfluidic device, a three-dimensional spider-inspired spinneret was directly fabricated in-chip via multiphoton lithography. Applying this unprecedented fabrication strategy, the to date smallest printed spinneret nozzle is produced. This spinneret resides tightly sealed, connecting it to the macroscopic world. Its functionality is demonstrated by wet-spinning of single-digit micron fibres through a polyacrylonitrile coagulation process induced by a water sheath layer. The methodology developed here demonstrates fabrication strategies to interface complex architectures into classical microfluidic platforms. Using multiphoton lithography for in-chip fabrication adopts a high spatial resolution technology for improving geometry and thus flow control inside microfluidic chips. The showcased fabrication methodology is generic and will be applicable to multiple challenges in fluid control and beyond.",1,https://api.osf.io/v2/files/5cebc4522a50c4001782b766/,218,https://engrxiv.org/dmpr3/,10.31224/osf.io/dmpr3,10.1039/C7LC01366C,2019-05-27T15:44:22.419441,2019-05-27T15:44:47.311780 | |
| r59ku,"Sinusoidal shaped hollow fibers for enhanced mass transfer","Geometrically structured flow channels induce secondary flows and vortices enhancing mass and heat transport rates. In particular, these vortices may reduce concentration polarization and subsequent fouling in membrane transport processes. In this work we present a new method of producing hollow fiber membranes with a sinusoidal change in diameter along the fiber length. We engineered a pulsation module that imposes a sinusoidally fluctuating bore liquid flow rate. Harmonic bore flow conditions can be varied over a wide range of operational settings. The fluctuating bore liquid flow rate translates into axial membrane properties varying with respect to inner bore diameter and wall thickness. | |
| We suggest that the resulting narrowing and widening of the membrane lumen channel induces secondary vortices to the liquid feed inside the membrane lumen. In gas/liquid membrane absorption processes these secondary vortices reduce the diffusional resistance, also known as the Bellhouse effect. For the produced hydrophobic PVDF membranes, improved oxygen transport from shell-to-lumen side prove superiority over straight hollow fiber membranes in G/L absorption process by a factor of 2.5 at higher liquid flow rates. We anticipate the dynamic flow module to be easily integrated into currently existing hollow fiber membrane spinning processes.",1,https://api.osf.io/v2/files/5cebc3d923fec40019e7f275/,192,https://engrxiv.org/r59ku/,10.31224/osf.io/r59ku,10.1016/j.memsci.2017.03.030,2019-05-27T15:41:28.094156,2019-05-27T15:41:48.369187 | |
| 5csy8,"3D-printed conductive static mixers enable all-vanadium redox ow battery using slurry electrodes","State-of-the-art all-vanadium redox flow batteries employ porous carbonaceous materials as electrodes. The battery cells possess non-scalable fixed electrodes inserted into a cell stack. In contrast, a conductive particle network dispersed in the electrolyte, known as slurry electrode, may be beneficial for a scalable redox flow battery. In this work, slurry electrodes are successfully introduced to an all-vanadium redox flow battery. Activated carbon and graphite powder particles are dispersed up to 20 wt% in the vanadium electrolyte and charge-discharge behavior is inspected via polarization studies. Graphite powder slurry is superior over activated carbon with a polarization behavior closer to the standard graphite felt electrodes. 3D-printed conductive static mixers introduced to the slurry channel improve the charge transfer via intensified slurry mixing and increased surface area. Consequently, a significant increase in the coulombic efficiency up to 95% and energy efficiency up to 65% is obtained. Our results show that slurry electrodes supported by conductive static mixers can be competitive to state-of-the-art electrodes yielding an additional degree of freedom in battery design. Research into carbon properties (particle size, internal surface area, pore size distribution) tailored to the electrolyte system and optimization of the mixer geometry may yield even better battery properties.",1,https://api.osf.io/v2/files/5cebc31735f2580018a8f495/,270,https://engrxiv.org/5csy8/,10.31224/osf.io/5csy8,10.1016/j.jpowsour.2018.01.061,2019-05-27T15:40:45.712037,2019-05-27T15:41:01.067521 | |
| uv7c2,"3D-printed electrodes with improved mass transport properties","Today's electrochemical reactor design is a less developed discipline as compared to electrocatalytic synthesis. Although catalysts show increasing conversion rates, they are often operated without measures for the reduction of concentration polarization effects. As a result, a stagnant boundary layer forms at the electrode‐electrolyte interface. This stagnant boundary layer presents an additional voltage drop and reduces the energy efficiency. It is generally accepted that this phenomenon is caused by a combination of fast electrode reactions and slow diffusion of the reacting species. Our earlier work demonstrated the potential of non‐conducting static mixers to reduce concentration polarization effects. However, there are few studies on conductive static mixers applied as electrodes. In this study, we present a new concept of additive manufactured flow through electrode mixers. Our electrode geometry combines a high surface area with mixing properties, diminishing concentration polarization effects of transport‐limited reactions. Mass transport properties of these conductive static mixers are evaluated in an additive manufactured electrochemical reactor under controlled conditions by applying the limiting‐current method.",1,https://api.osf.io/v2/files/5cebc1e623fec40017ec33d8/,277,https://engrxiv.org/uv7c2/,10.31224/osf.io/uv7c2,10.1002/celc.201700662,2019-05-27T15:38:11.808256,2019-05-27T15:38:29.429304 | |
| c267u,"Fouling Mitigation in Tubular Membranes by 3D-printed Twisted Tape Turbulence Promoters","Despite intensive research, fouling remains a severe problem in membrane filtration. It is often controlled by applying turbulent flow which requires a higher energy consumption. So-called turbulence promoters or static mixers can be inserted into the flow channel of tubular membranes. They deflect the fluid, induce vortices, enhance particle back-transport and increase the shear rate at the membrane surface, thus mitigating fouling. However, little is known how the geometry of such turbulence promotors affects the reduction of fouling. We investigate how different 3D-printed mixer geometries affect fouling and improve the flux during filtration with humic acid. Most mixer geometries used in the present study are based on a twisted tape; a Kenics static mixer is investigated as well. Static mixers with changing diameter prove to be less effective than twisted tape mixers with constant diameter which lead to an increase in permeate flux of around 130%. The highest flux improvement of 140% can be reached by applying a Kenics mixer. Regardless of their geometry, all investigated static mixer cause higher permeate fluxes at same specific energy consumption. Again, the Kenics mixer proves to be the most efficient static mixer. The presented mixer geometries can be fabricated with undercut injection molding techniques and represent a simple and viable option to make tubular membrane based filtration processes more efficient.",1,https://api.osf.io/v2/files/5cebc0692a50c4001782b4cc/,249,https://engrxiv.org/c267u/,10.31224/osf.io/c267u,10.1016/j.memsci.2018.02.015,2019-05-27T14:47:52.160991,2019-05-27T14:48:07.030404 | |
| r4hax,"3D-printed rotating spinnerets create membranes with a twist","Round hollow fiber membranes have been well established in applications such as gas separation, ultrafiltration and blood dialysis. Yet, it is well known that geometrical topologies can introduce secondary flow patterns counteracting mass transport limitations, stemming from diffusion resistances and fouling. We present a new systematic methodology to fabricate novel membrane architectures. We use the freedom of design by 3D-printing spinnerets, having multiple bore channels of any geometry. First, such spinnerets are stationary to fabricate straight bore channels inside a monolithic membrane. Second, in an even more complex design, a new mechanical system enables rotating the spinneret. Such rotating multibore spinnerets enable (A) the preparation of twisted channels inside a porous monolithic membrane as well as (B) a helical twist of the outside geometry. The spun material systems comprise classical polymer solutions as well as metal-polymer slurries resulting in solid porous metallic monolithic membrane after thermal post-processing. It is known that twisted spiral-type bore channel geometries are potentially superior to straight channels with respect to mass and heat polarization phenomena, however their fabrication was cumbersome in the past. Now, the described methodology enables membrane fabrication to tailor the membrane geometry to the needs of the membrane process. To showcase the delicate interplay between the geometry and radial and axial flow conditions, we report fluid mechanical simulations and flow magnetic resonance imaging measurements for a twisted tri-bore membrane during permeation.",1,https://api.osf.io/v2/files/5cebbf408d6e0500186428cd/,120,https://engrxiv.org/r4hax/,10.31224/osf.io/r4hax,10.1016/j.memsci.2018.03.026,2019-05-27T14:46:55.347551,2019-05-27T14:47:27.379806 | |
| d6wsr,"Flow and filtration imaging of single use sterile membrane filters","Sterile filters incorporating endotoxin adsorption function emerged recently to pretreat dialysate liquids fed to a hemodialysis filtration process. Their application significantly enhances the survival rate during dialysis treatment as they function as steril filters as well as an endotoxin adsorber. Little is known about the fluid flow distribution in such single use membrane modules. We report a detailed analysis of the local 3D flow field distribution in such membrane modules using magnetic resonance flow imaging. Next to pure water filtration representing the application case of endotoxin adsorption from an already pure liquid, we also used the module as a filtration device rejecting for instance colloidal silica. Such experiments performed in-situ allow the quantification of cake layer development and its concomitant redistribution of the flow field. Particularly novel is the quantification of the time evolution of local permeate flux distribution. These detailed insights of this study encourage the use of flow-MRI when designing and applying new membrane module configurations.",1,https://api.osf.io/v2/files/5cebbe5323fec40019e7eff5/,227,https://engrxiv.org/d6wsr/,10.31224/osf.io/d6wsr,10.1016/j.memsci.2018.02.002,2019-05-27T14:46:14.916781,2019-05-27T14:46:48.760793 | |
| tqnx4,"What are the microscopic events of colloidal membrane fouling?","Due to the complex interplay between surface adsorption and hydrodynamic interactions, representative microsocpic mechanisms of colloidal membrane fouling are still not well understood. Numerical simulations overcome experimental limitations such as the temporal and spatial resolution of microscopic events during colloidal membrane fouling: they help to gain deeper insight into fouling processes. This study uses coupled computational fluid dynamics - discrete element methods (CFD-DEM) simulations to examine mechanisms of colloidal fouling in a microfluidic architecture mimicking a porous microfiltration membrane. We pay special attention to how particles can overcome energy barriers leading to adsorption and desorption with each other and with the external and internal membrane surface. Interparticle interaction leads to a transition from the secondary to the primary minimum of the DLVO potential. Adsorbed particles can show re-entrainment or they can glide downstream. Since particles mainly resuspend as clusters, the inner pore geometry significantly affects the fouling behavior. The findings allow a basic understanding of microscopic fouling events during colloidal filtration. The methodology enables future systematic studies on the interplay of hydrodynamic conditions and surface energy contributions represented by potentials for soft and patchy colloids.",1,https://api.osf.io/v2/files/5cebbd0635f2580018a8f282/,270,https://engrxiv.org/tqnx4/,10.31224/osf.io/tqnx4,10.1016/j.memsci.2018.02.023,2019-05-27T14:45:22.347257,2019-05-27T14:45:42.010978 | |
| r82zn,"Implementation of a Dynamic Network Model of the Nigerian Transmission Grid for Investigations on Power System Stability","Electricity is the backbone of any modern society and economy. Therefore, economic growth and an increase in social wealth of a country usually lead to an increase in demand for electrical energy especially for a country as Nigeria. As the population of Nigeria is increasing exponentially, there exists a need to make basic needs constantly available, for the wellbeing of the increasing population. This is possible through mechanization. Reliable and stable electricity supply is the surest means to this end. As a result, there is a need to constantly review the dynamics of the power system while more energy sources and loads are being added to the existing power network grid. This creates a demand for precise models for the corresponding network. In this paper, the power network system of the Nigerian transmission grid was implemented at normal operations to include the dynamic models to the corresponding network elements (i.e. generation Units based on their installed capacities and controllers). With the help of this model, stationary load flow calculations, as well as the network’s model performance in steady state was conducted. The network’s model performance in the case of load changes and fault operations was also carried out. These allowed for investigations on the stability status of the Nigerian transmission grid.",1,https://api.osf.io/v2/files/5cea7b252a50c400167d61d5/,338,https://engrxiv.org/r82zn/,10.31224/osf.io/r82zn,,2019-05-27T14:44:37.411762,2019-05-27T14:45:02.162536 | |
| 46p9q,"Uncovering the dynamic fracture behavior of PMMA","Experimental investigations of dynamic crack propagation in PMMA induced by impact show single cracks running at around 300-400 m/s. Existing numerical models for simulating dynamic fracture in PMMA consistently produce crack propagation speeds significantly higher than those measured experimentally. Here we uncover the reason for this puzzle by showing that localized softening in the fracture process zone (caused by heating due to high strain rates in front of the crack tip), leads to crack propagation speeds that match the observed ones. We introduce a new constitutive model in our peridynamic formulation for PMMA to account for material softening in the crack tip region. With the new model, the computed crack speed and crack length evolution match very closely those found experimentally.",1,https://api.osf.io/v2/files/5cdf314c35f2580016a4b3e2/,335,https://engrxiv.org/46p9q/,10.31224/osf.io/46p9q,10.1016/j.engfracmech.2019.106617,2019-05-18T00:27:07.538411,2019-08-20T02:43:52.749495 | |
| j6vyg,"Load distribution in threads of porous metal-ceramic functionally graded composite joints subjected to thermomechanical loading","Metal-ceramic functionally graded materials (FGMs) have been extensively used in aerospace engineering where high strength and excellent heat insulation materials are desired. In this paper, load distribution in threads of the Thermal Protection System used bolted joint made up of porous ZrO2/(ZrO2+Ni) FGMs is investigated by ABAQUS codes. The bolted joint is subjected to reentry heating corresponding to the Access to Space Vehicle. Effects of bolt-nut parameters including thread tooth profile, thread pitch, and modulus ratio of bolt to nut on load distribution in threads are analyzed in detail. It is found that uneven load distribution in threads occurs at elevated temperature, which mainly focuses on the first two threads closest to the nut bearing surface, with the first thread carrying 74% of the total load. Bolt-nut parameters have great effects on load distribution in threads, with trapezoidal thread, extra fine thread and greater modulus ratio of bolt to nut leading to more evenly distributed load. Further studies show that nut shape has significant effects on load distribution in threads, the optimized nut is designed to make the maximum load bearing ratio of the thread decrease to 30.21%, and thus the service reliability of the bolted joint is greatly improved.",1,https://api.osf.io/v2/files/5cdd4e26db3c0a0016d35b3d/,127,https://engrxiv.org/j6vyg/,10.31224/osf.io/j6vyg,10.1016/j.compstruct.2015.08.113,2019-05-16T13:54:07.317012,2019-05-16T13:54:21.744127 | |
| xp7va,"Design and analysis of the porous ZrO2/(ZrO2+Ni) ceramic joint with load bearing-heat insulation integration","The joining of ceramics with metals is widely used in aerospace engineering where high strength and excellent heat insulation materials are desired. In this paper, a new multifunctional bolted joint with load bearing-heat insulation integration is prepared with porous ZrO2/(ZrO2+Ni) sandwich ceramics. Double-shear behavior of the bolted joint connecting C/SiC plates is analyzed by ABAQUS codes. It is found that shearing damage occurs at shearing faces of the bolt, the shearing failure faces are layered rather than smooth. To improve its shearing strength, we introduce the shear band (ZrO2+V%Ni of thickness h) to its shearing faces. Results show that the shear band can improve the shearing strength and slow down the attenuation of load bearing capacity after reaching the shearing strength, without obviously increasing the thermal conductivity. An optimal structural design is performed and proper shear band is defined to balance the shearing strength and heat insulation performance of the ceramic joint.",1,https://api.osf.io/v2/files/5cdd4cd1db3c0a0017d21cc8/,116,https://engrxiv.org/xp7va/,10.31224/osf.io/xp7va,10.1016/j.ceramint.2015.09.085,2019-05-16T13:53:25.695965,2019-05-16T13:53:43.663610 | |
| x9emb,"A Solution for Dynamic Spectrum Management in Mission-Critical UAV Networks","In this paper, we study the problem of spectrum scarcity in a network of unmanned aerial vehicles (UAVs) during mission-critical applications such as disaster monitoring and public safety missions, where the pre-allocated spectrum is not sufficient to offer a high data transmission rate for real-time video streaming. In such scenarios, the UAV network can lease part of the spectrum of a terrestrial licensed network in exchange for providing relaying service. In order to optimize the performance of the UAV network and prolong its lifetime, some of the UAVs will function as a relay for the primary network while the rest of the UAVs carry out their sensing tasks. Here, we propose a team reinforcement learning algorithm performed by the UAV's controller unit to determine the optimum allocation of sensing and relaying tasks among the UAVs as well as their relocation strategy at each time. We analyze the convergence of our algorithm and present simulation results to evaluate the system throughput in different scenarios.",1,https://api.osf.io/v2/files/5cdc7b82db3c0a0016d27fe4/,233,https://engrxiv.org/x9emb/,10.31224/osf.io/x9emb,,2019-05-16T01:36:03.424010,2019-05-16T01:36:26.880467 | |
| xnq4t,"How much energy can optimal control of domestic water heating save?","Scheduled control of domestic electric water heaters, designed to cut energy use while minimising the impact on users' comfort and convenience, has been fairly common for some time in a number of countries. The aim is usually load-shifting (by heating water at off-peak times) and/or maximising time-of-use pricing benefits for users. The scheduling tends not to be linked to actual hot water usage and depends largely on stored thermal energy. Heat losses therefore tend to be greater than if the heater ran without a break. The effect of such a control strategy is thus to worsen the energy loss and in most cases increase greenhouse gas emissions. Many developing countries have flat-pricing (no time-of-use incentives) and rely heavily on energy from fossil fuels, making these considerations even more pressing. We explore three strategies for optimal control of domestic water heating that do not use thermostat control: matching the delivery temperature in the hot water, matching the energy delivered in the hot water, and a variation of the second strategy which provides for Legionella sterilisation. For each of these strategies we examine the energy used in heating, the energy delivered at the tank outlet, and issues of convenience to the user. The study differs from most previous work in that it uses real daily hot-water usage profiles, ensures like-for-like comparison in delivered energy at the point of use, and includes a daily Legionella avoidance strategy. We tackled this as an optimal control problem using dynamic programming. Our results demonstrate a median energy saving of between 8\ and 18% for the three strategies. Even more savings would be realised if intended and unintended usage events are correctly classified, and the optimal control only plans for intended usage events.",1,https://api.osf.io/v2/files/5cdb46e12d1b9e001ba323d2/,330,https://engrxiv.org/xnq4t/,10.31224/osf.io/xnq4t,10.1016/j.esd.2019.05.004,2019-05-15T13:00:45.581452,2019-08-06T07:44:05.993457 | |
| 5xv76,"Frequency Analysis of Vortex Shedding in Wake Area behind the NACA0012 Airfoil via Fully-Lagrangian Vortex Element Method","Shedding frequency of the vortices of the low-pressure area behind NACA0012 airfoil cross-section is provided for a laminar flow of an incompressible viscose fluid using Lagrangian vortex elements scheme. In the current work, only those areas of the solution domain were modeled where there are velocity gradients. It was done by the vorticity transfer equation that was obtained by calculating the cross product of the sides of the momentum equation. According to the Fractional Step method, the vorticity transfer equation was separated into two different equations that were solved sequentially in each time step: non-linear convection equation and the linear diffusion equation. Vorticity field in the physical domain was separated by the sheet and bubble vortices and each of the vortex elements in the solving field moved according to Biot-Savar Law and diffused according to the random walk method. The flow around the airfoil was obtained using Joukowsly mapping of the solution of the flow around a circle. This work was validated by comparing the aerodynamics force coefficients obtained from the vortex elements method with those obtained from analytical methods. Vortex shedding frequencies were calculated using the Fourier transform of the time response of the changes in the aerodynamic forces, being compared to the experimental results under the same conditions.",1,https://api.osf.io/v2/files/5cda3709c2ae0b001a4cd77a/,250,https://engrxiv.org/5xv76/,10.31224/osf.io/5xv76,,2019-05-14T17:41:32.692497,2019-05-14T17:42:06.885581 | |
| meb53,"A comparative evaluation of the impact of average speed enforcement (ASE) on passenger and minibus taxi vehicle drivers on the R61 in South Africa","Average Speed Enforcement (ASE) is an emergent alternative to instantaneous speed limit enforcement to improve road safety, and is used to enforce an average speed limit over a road segment. This paper presents a study on the response of passenger vehicles and minibus taxis to ASE on the R61 in South Africa. A spatio-temporal quantitative study of speed compliance is conducted, where metrics such as speed variability, average speed and 85th percentile speed measured prior to, and during enforcement are analysed for two prominent modes of transport – passenger vehicles and minibus taxis. These measurements are taken on the enforcement route and on control routes adjacent to and further away from the enforcement route. A qualitative study is also conducted to evaluate the relationship between speed compliance and driver understanding of the system. The impact of the system on crash risk and injury severity is also examined before and during enforcement. For passenger vehicles, results show that the introduction of ASE was followed by a reduction in mean speed on the enforcement route and adjacent control route. For minibus taxis, it was found that ASE appears to have little influence on improving speed compliance, which is likely associated with a lack of driver understanding on how the system operates.",1,https://api.osf.io/v2/files/5cda34abdb3c0a0017cfef6b/,227,https://engrxiv.org/meb53/,10.31224/osf.io/meb53,10.1016/j.esd.2019.03.004,2019-05-14T17:40:26.514605,2019-05-28T02:43:27.498229 | |
| m67ew,"On the analytical approach to the linear analysis of an arbitrarily curved spatial Bernoulli-Euler beam","The equilibrium and kinematic equations of an arbitrarily curved spatial Bernoulli-Euler beam are derived with respect to a parametric coordinate and compared with those of the Timoshenko beam. It is shown that the beam analogy follows from the fact that the left-hand side in all the four sets of those equations are the covariant derivatives of unknown vector. Furthermore, an elegant primal form of the equilibrium equations is composed. No additional assumptions, besides those of the linear Bernoulli-Euler theory, are introduced, which makes the theory ideally suited for the analytical assessment of big-curvature beams. The curvature change is derived with respect to both convective and material/spatial coordinates, and some aspects of its definition are discussed. Additionally, the stiffness matrix of an arbitrarily curved spatial beam is calculated with the flexibility approach utilizing the relative coordinate system. The numerical analysis of the carefully selected set of examples proved that the present analytical formulation can deliver valid benchmark results for testing of the purely numeric methods.",1,https://api.osf.io/v2/files/5cd9658a840cae0018703dec/,230,https://engrxiv.org/m67ew/,10.31224/osf.io/m67ew,,2019-05-13T14:17:42.671076,2019-05-13T14:18:01.434916 | |
| nygd8,"Empirical validation of a data-driven heating demand simulation with error correction methods","Advanced control concepts for building energy systems, such as Model Predictive Control, often require models that forecast the energy demand of a building. Such models are commonly based on first principles, however the cost and effort required to develop such models may be prohibitive for real-life applications. As an alternative, we introduce and validate a data-driven simulation approach based on Artificial Neural Networks to forecast the heating demand of buildings. The forecast is enhanced with the help of two correction methods, based on online learning and forecast error auto-correlation. Validation results based on data from four office buildings suggest that our method shows better forecasting performance than a fitted 5R3C building model.",1,https://api.osf.io/v2/files/5cd93919f244ec001ee80c3d/,292,https://engrxiv.org/nygd8/,10.31224/osf.io/nygd8,,2019-05-13T14:13:30.404039,2019-05-13T14:13:48.322942 | |
| vxw6g,"Improved day ahead heating demand forecasting by online correction methods","To reduce the heating and cooling energy demand of buildings and districts novel control strategies are constantly being developed that require information on the future demand of the controlled entity. Demand forecasting is commonly done with deterministic white box models or fitted grey-box models, however, recently more and more data and machine learning based approaches are being developed. All approaches have weaknesses: white-box models require major modelling effort, grey-box approaches are limited by their model or parameter complexity and machine learning is dependent on hyperparameters, some of which are randomly chosen, and therefore considered unreliable. | |
| Here we develop a forecasting approach based on Artificial Neural Networks (ANN) and introduce error correction methods based on online learning and the learned autocorrelation of the forecasting error. We compare the approach to other regression based and grey-box methods in a real case study of a small-scale district energy system with mixed use and unknown lower-level control. We show that the proposed method outperforms the other forecasting methods in terms of average error and coefficient of determination. We further demonstrate that in our case study the error correction methods significantly reduce variance in ANN performance created by randomly initialized parameters in the networks.",1,https://api.osf.io/v2/files/5cd92d75f244ec001ee7ff31/,321,https://engrxiv.org/vxw6g/,10.31224/osf.io/vxw6g,,2019-05-13T14:12:53.046463,2019-05-13T14:13:27.174233 | |
| 7bvwp,"Polyethylene terephthalate fibers with exotic microstructures [The Lost Archive Digitalization Program; OCR Report Index: 181906-2].","Polyethylene terephthalate fibers with exotic microstructures [The Lost Archive Digitalization Program; OCR Report Index: 181906-2].",1,https://api.osf.io/v2/files/5cd8180ef8214b00198a6738/,203,https://engrxiv.org/7bvwp/,10.31224/osf.io/7bvwp,,2019-05-13T14:04:04.002267,2019-05-13T14:04:22.859399 | |
| qud3y,"Polyethylene terephthalate technical sample [The Lost Archive Digitalization Program; OCR Report Index: 181906].","OCR Report Index: 181906; Object: Polyethylene terephthalate film sample. DEFIN.: Polyethylene terephthalate (sometimes written poly(ethylene terephthalate)), commonly abbreviated PET, PETE, or the obsolete PETP or PET-P, is the most common thermoplastic polymer resin of the polyester family and is used in fibres for clothing, containers for liquids and foods, thermoforming for manufacturing, and in combination with glass fibre for engineering resins.",1,https://api.osf.io/v2/files/5cd80d2ff244ec001ee6f331/,177,https://engrxiv.org/qud3y/,10.31224/osf.io/qud3y,,2019-05-13T14:04:44.386456,2019-05-13T14:05:01.601029 | |
| 8rx9q,"Second-generation composites from recycled wind turbine blades","The demand for wind and other forms of clean energy is increasing in the US and throughout the world. Wind energy is also expected to provide 14.9% of the global electricity demand by 2020. Under this scenario, a significant amount of wind turbine blades (WTBs) will continue to burden our current landfills until a viable recycling strategy is found. Repurposing or recycling of end- of-use wind turbine blade material will provide both economic and environmental attributes.",1,https://api.osf.io/v2/files/5cd7ba44054f5b00175db66b/,280,https://engrxiv.org/8rx9q/,10.31224/osf.io/8rx9q,,2019-05-13T13:53:47.870050,2019-06-21T23:36:22.794811 | |
| xge6z,"Characterization of the physical properties of extruded composites from recycled wind turbine blade material","Wind turbine blades (WTB) mechanically recycled and used as a feedstock for thermoplastic composites. Physical properties (water sorption (WA), Thickness swelling (TS)) dataset of composites made from recycled wind turbine blades presented. Dataset also presented the influence of resin level, mill screen size and coupling agents on the physical properties of composites.",1,https://api.osf.io/v2/files/5cd7b5ab054f5b00175db058/,180,https://engrxiv.org/xge6z/,10.31224/osf.io/xge6z,,2019-05-13T13:51:50.522607,2019-05-13T13:52:07.231656 | |
| axknf,"Experimental data on the mechanical properties of extruded composites from recycled wind turbine blade material","The wind turbine blades (WTB) that face end-of-life was first mechanically milled and classified through a range of varying screen sizes. We then blended this with high density polyethylene (HDPE) thermoplastic resin and extruded it to a profiled composite. We determined the influence of refined particle size, resin content and coupling agents (maleic anhydride polyethylene (MAPE) and methacryloxypropyltriethoxysilane (Silane)) on the mechanical properties of recycled composites [1].",1,https://api.osf.io/v2/files/5cd7b46cf244ec0020e41674/,178,https://engrxiv.org/axknf/,10.31224/osf.io/axknf,,2019-05-13T13:49:25.150941,2019-05-13T13:49:41.598525 | |
| 2fdut,"Equivalent Neutral Axis for Structural Condition Assessment using Multi-sensor Fusion","Damage detection is one of the primary purposes of structural health monitoring. Since neutral axis location changes have been considered to be sensitive damage indicators, extensive research efforts have been devoted to developing effective and accurate neutral axis estimation methods, although challenges remain in real-world applications. This report proposes a novel structural condition assessment method using an equivalent neutral axis (ENA) at each location at which a sensor is installed that can be estimated based on acceleration and strain measurements. Numerical simulations were conducted using a simply supported steel beam model to investigate the effect of the ENA with respect to the sensor configuration and damage level. The proposed method was also applied to a numerical reinforced concrete beam model to further validate the ENA as a damage indicator, thus proving the sensitivity of the ENA to structural damage",1,https://api.osf.io/v2/files/5cd4f2d7f244ec001fe355d1/,185,https://engrxiv.org/2fdut/,10.31224/osf.io/2fdut,,2019-05-10T15:18:12.501669,2019-05-10T15:18:41.506909 | |
| csvfh,"Toward coordinated transmission and distribution operations","Proliferation of smart grid technologies has enhanced observability and controllability of distribution systems. If coordinated with the transmission system, resources of both systems can be used more efficiently. This paper proposes a model to operate transmission and distribution systems in a coordinated manner. The proposed model is solved using a Surrogate Lagrangian Relaxation (SLR) approach. The computational performance of this approach is compared against existing methods (e.g. subgradient method). Finally, the usefulness of the proposed model and solution approach is demonstrated via numerical experiments on the illustrative example and IEEE benchmarks.",1,https://api.osf.io/v2/files/5cd1f38978f7c7001a092a11/,183,https://engrxiv.org/csvfh/,10.31224/osf.io/csvfh,,2019-05-07T21:15:09.904127,2019-05-07T21:16:21.422319 | |
| evd92,"Coefficient of Linear Thermal Expansion (CLTE) dataset of extruded composites from recycled wind turbine blade material","The coefficient of linear thermal expansion (CLTE often referred to as “α”) is a material property which characterizes the ability of a plastic to expand under the effect of temperature elevation. We determined CLTE of extruded fiber-reinforced composites manufactured from recycled wind turbine blade (rWTB) material by considering the influence of particle size, resin content and MAPE as a coupling agent [1].",1,https://api.osf.io/v2/files/5ccfda7078c993001ed3737d/,184,https://engrxiv.org/evd92/,10.31224/osf.io/evd92,,2019-05-06T14:06:13.131187,2019-05-12T05:48:32.373277 | |
| 2aub6,"LAB-ON-A-DISH RAPID PROTOTYPING AND MICROSCOPIC INVESTIGATIONS OF LAB-ON-A-DISH GEOMETRIES (INCLUDING DYE DIFFUSION STUDIES)","The problem of compatibilities of fluorescence techniques and polymer chips is resolved (as a part of the general chip optics problem) using microscopic investigations of polymer chip transparency in some different textural variances and microfluorimetric measurements of fluorescent dyes in the chip geometry. The problem of the soil chip prototyping is solved using 3D-printing based on some biocompatible and, so possible, biodegradable polymers. The basic complexity of experimental data is provided in the tables placed in the general article text. Is it possible to create multiparametric analytical technique for synchronous biocompatible soil microbiome analysis and monitoring? It is a general question for the real time environmental control. We can say “Yes”, but only if we have a minimal prerequisite case, which we have a good polymer, real “real time” analyzer, biocompatible and biodegradable coatings etc. In other cases the general problem of soil chip design is not a problem of engineering, but it is a problem of soil-chip interface chemical physics and physical chemistry. Such problem may be interpreted only as a principal physical, but not as a technical problem.",1,https://api.osf.io/v2/files/5cced497103390001a9bea6b/,235,https://engrxiv.org/2aub6/,10.31224/osf.io/2aub6,,2019-05-06T14:05:20.392018,2019-05-07T19:30:27.717172 | |
| 6cjzf,"Using thermal transients at the outlet of electrical water heaters to recognise consumption patterns for heating schedule optimisation","In the midst of environmental concerns, and soaring energy costs and energy shortages, the efficiency of electrical household water heaters (EWHs) has been identified as an area with significant potential for savings. The benefits of applying optimised scheduling control for EWHs has been proven by various studies, however, little has been done to measure individual behaviour. This paper presents an alternative to the invasive and expensive solution of using water flow meters. A hardware and algorithmic solution is presented that uses thermal transients at the outlet of an EWH to measure consumption patterns. The results show that the approach is able to detect usage events with an accuracy of 91%. Despite the challenges related to thermal inaccuracies, event durations are estimated to within 2 minutes accuracy 79% of the time.",1,https://api.osf.io/v2/files/5ccec61278c993001cd31be1/,236,https://engrxiv.org/6cjzf/,10.31224/osf.io/6cjzf,10.1109/NTMS.2015.7266530,2019-05-06T14:03:31.127787,2019-05-07T19:30:48.488426 | |
| se8hx,"Can open-loop control algorithms solve the data center switching problem?","There is a world-wide push to create the next generation all-optical transmission and switching technologies for exascale data centers. In this paper we focus on the switching fabrics. Many different types of 2D architectures are being explored including MEMS/waveguides and semiconductor optical amplifiers. However, these tend to suffer from high, path dependent losses and crosstalk issues. The technologies with the best optical properties demonstrated to date in large fabrics (>100 ports) are 3D MEMS beam steering approaches. These have low average insertion losses, and equally important, a narrow loss distribution. However, 3D MEMS fabrics are generally dismissed from serious consideration for this application because of their slow switching speeds (~few milliseconds) and costs ($100/port). In this paper we show how novel feedforward open loop controls can solve both problems by improving switching speeds by two orders of magnitude and costs by one order of magnitude. With these improvements in hand, we believe 3D MEMS fabrics can become the technology of choice for data centers.",1,https://api.osf.io/v2/files/5cccac8237b4fe001750dfef/,321,https://engrxiv.org/se8hx/,10.31224/osf.io/se8hx,,2019-05-04T01:40:12.011794,2019-05-04T01:40:32.283494 | |
| 69puh,"Derivation, Design and Simulation of the Single-Ended Primary-Inductor Converter (SEPIC)","The purpose of the paper is to guide engineering students and ease their transition from the most basic DC-DC converter topologies to more advanced types. The buck, boost and buck-boost converters are the usual suspects in textbooks and engineering classes to introduce students to the basics of power electronics and switch mode power supplies. There is a gap of how detailed such second order DC-DC converters are described and the more advanced fourth order such as the Cuk, Zeta and Single-Ended Primary-Inductor Converter (SEPIC). This paper gives a detailed derivation of the equations governing the SEPIC. An example of sizing of components is presented for a range of input voltages and power levels. Finally the design is verified by a circuit simulation using LTSpice.",1,https://api.osf.io/v2/files/5ccae88e42c4b70018b68715/,735,https://engrxiv.org/69puh/,10.31224/osf.io/69puh,,2019-05-02T14:27:43.843092,2019-05-03T13:30:02.343721 | |
| k82ca,"Polymer Nanocomposites having a High Filler Content: Synthesis, Structures, Properties, and Applications","The recent development of nanoscale fillers, such as carbon nanotube, graphene, and nanocellulose, allows the functionality of polymer nanocomposites to be controlled and enhanced. However, conventional synthesis methods of polymer nanocomposites cannot maximise the reinforcement of these nanofillers at high filler content. Approaches to the synthesis of high content filler polymer nanocomposites are suggested to facilitate future applications. The fabrication methods address design of the polymer nanocomposite architecture, which encompass one, two, and three dimensional morphology. Factors that hamper the reinforcement of nanostructures, such as alignment, dispersion of filler as well as interfacial bonding between filler and polymer are outlined. Using suitable approaches, maximum potential reinforcement of nanoscale filler can be anticipated without limitations in orientation, dispersion, and the integrity of the filler particle-matrix interface. High filler content polymer composites containing emerging materials such as 2D transition metal carbides, nitrides, and carbonitrides (MXenes) are expected in the future.",1,https://api.osf.io/v2/files/5cc8f48e42c4b70017b85869/,223,https://engrxiv.org/k82ca/,10.31224/osf.io/k82ca,10.1039/C9NR00117D,2019-05-01T16:01:37.771261,2019-05-01T16:04:23.738308 | |
| pkdwt,"Automated analysis of neck muscle boundaries for cervical dystonia using ultrasound imaging and deep learning","Objective: To provide an automated visualization, pattern analysis and classification of neck muscle boundaries comparing cervical dystonia with healthy controls. Methods: We recorded transverse cervical ultrasound (US) images and whole-body motion analysis of sixty-one standing participants (35 cervical dystonia, 26 age matched controls). We manually annotated 3,100 images sampling a range of pitch, yaw, and roll head movements (2,000 this dataset, 1,100 previous dataset of 28 healthy participants), and trained, validated and tested a deep residual deconvolutional neural network (DCNN) to classify pixels to 13 categories (five paired neck muscles, skin, ligamentum nuchae, vertebra). For all participants in their normal standing posture, we generated held out DCNN segmented US images, extracted segmentation boundaries, transformed the boundaries to principal components and clustered the dystonia participants into two groups using their component scores. Results: For all segments, metrics of segmentation accuracy were Jaccard Index (50±21%) and Hausdorff Distance (5.8±4 mm). For the four deep muscle layers, their boundaries were used to predict central injection sites for each muscle with average precision 94±2%. Using 10-fold cross-validation to select predictive components, linear analysis of component scores identified two significant eigen-patterns discriminating Dystonia from Controls and classifying group membership (Dystonia1, Dystonia2, Control) correctly at 93.4%. Motion analysis showed the groups differed significantly according to head yaw-rotation posture and truncal posture. Conclusion: Neck muscle shape alone discriminates dystonia from healthy controls. Significance: Using deep learning, US imaging allows online, automated visualization, pattern analysis, diagnostic classification of cervical dystonia and segmentation of individual muscles for targeted injection.",1,https://api.osf.io/v2/files/5cc745a1d7dc3f00176ad441/,280,https://engrxiv.org/pkdwt/,10.31224/osf.io/pkdwt,,2019-04-29T21:21:05.443181,2019-04-30T13:50:33.624225 | |
| rdeq4,"Analytical modelling of thermal residual stresses and optimal design of ZrO2-(ZrO2+Ni) sandwich ceramics","The joining of ceramics with metals have been extensively used in applications requiring high strength and excellent heat insulation. However, evaluating the residual stress generated inevitably due to the mismatch in coefficients of thermal expansion of ceramic and metal is challenging, which is very important for fabrication and characterization of layered inhomogeneous material. A simplified analytical model considering the overall deformation compatibility is established to compute the interlaminar residual stresses of the ZrO2/(ZrO2+Ni) sandwich ceramics, which agrees well with the results obtained by the commercial finite element package. The effects of the thickness ratio of the transitional layer to the middle layer, and the number of transitional layers on the properties of the ZrO2/(ZrO2+Ni) sandwich ceramics are researched to obtain the optimal structure.",1,https://api.osf.io/v2/files/5cc72b6200a810001a5a59a7/,230,https://engrxiv.org/rdeq4/,10.31224/osf.io/rdeq4,10.1016/j.ceramint.2015.03.025,2019-04-29T17:50:02.115101,2019-04-29T20:41:34.680586 | |
| bvhzc,"Preparation and thermodynamic analysis of the porous functionally graded bolted joint","Ceramic-metal functionally graded materials (FGMs) have been extensively used in aerospace engineering where high strength and excellent heat insulation materials are desired. In this paper, the thermodynamic behavior of the Thermal Protection System (TPS) used bolted joints made up of porous ZrO2/(ZrO2+Ni) FGMs is investigated by finite-element (FE) modeling. The bolted joint is subjected to reentry heating corresponding to the Access to Space Vehicle. Thermodynamic simulations are carried out to yield the transient response of the porous ZrO2/(ZrO2+Ni) functionally graded bolted joint (FGBJ). The effects of the preload on the thermomechanical behavior and service reliability of the bolted joint are numerically analyzed in detail by ABAQUS codes. It is found that the preload relaxation of the bolted joint occurs at elevated temperature, and the preload has significant influence on service reliability of the bolted joint under transient thermomechanical circumstances. With the increase of the preload, stress concentration which occurs at the root of the first thread of the bolt increases rapidly and predominates in service reliability. Proper preload is thus defined to balance the service reliability and tightness of the bolted joint. Further studies show that the shape of the nut has a great effect on the stress concentration of the thread, the optimized nut is designed to reduce the stress concentration of the thread, and thus the reliability of the bolted joint is also improved.",1,https://api.osf.io/v2/files/5cc7210000a81000175be4ca/,249,https://engrxiv.org/bvhzc/,10.31224/osf.io/bvhzc,10.1016/j.compositesb.2015.07.018,2019-04-29T16:46:33.143636,2019-04-29T19:39:23.490648 | |
| 3q479,"Measuring residual stress and its influence on properties of porous ZrO2-(ZrO2+Ni) ceramics","Ceramic-metal functionally graded materials (FGMs) have been extensively used in aerospace engineering where high strength and excellent heat insulation materials are desired. However, their performance depends highly on the internal residual stress, which is generated inevitably due to the thermal mismatch of ceramic and metal. In this paper, based on the nanoindentation test, the field distribution of the residual stress of porous ZrO2/(ZrO2+Ni) ceramic-metal FGMs is measured. The residual stress field measured by nanoindentation agrees qualitatively with the finite element simulation results. Then a constitutive relation is established to investigate the effects of residual stress on the macroscopic deformation behavior of porous ZrO2/(ZrO2+Ni) FGMs, which agrees well with the bending and compression experiments. It is found that residual stress can improve both the flexural strength and stiffness of the porous ZrO2/(ZrO2+Ni) FGMs, by densifying and compensating the tensile stress of the porous middle layer (ZrO2) during the bending process, respectively. However, it has no obvious influence on the ultimate compressive strength of the porous ZrO2/(ZrO2+Ni) FGMs, but mainly influences its initial stage of elastic deformation in the compressive behavior.",1,https://api.osf.io/v2/files/5cc71db700a81000185ac846/,231,https://engrxiv.org/3q479/,10.31224/osf.io/3q479,10.1016/j.msea.2014.11.018,2019-04-29T16:01:16.121585,2019-04-29T18:47:50.976594 | |
| ykrve,"A bibliometric contribution of the strategies of reverse logistics in waste electrical and electronic equipment (weee) management","In recent years, with the increasing of waste, the reverse logistics become an important strategy for meeting the necessaries of the society and work market. Among the huge amount of discard products are the waste electrical and electronic equipment (WEEE), which it has become a major problem for developing countries due to its harmful effects. This paper characterizes and analyses the bibliometric review of the reverse logistics strategies applied in Waste Electrical and Electronic Equipment (WEEE) Management. The methodological approach used is the systematic review of the literature, based on bibliometric theory, through consultation with the ISI Web bases of Science and Scopus, and their treatment by Excel and Mendeley software. For research was used ``Reverse Logistics'' and ``WEEE'' as an expressions key, generating a sample of 43 articles published. At the end of the study were presented descriptive analysis results with the identification of the years, authors, research source, countries and research methods, and a bibliometric analysis results by the number of citations.",1,https://api.osf.io/v2/files/5cc4976ed7dc3f00166a34c0/,304,https://engrxiv.org/ykrve/,10.31224/osf.io/ykrve,,2019-04-28T00:53:25.651262,2019-10-29T04:51:02.314111 | |
| nbh6c,"The Smart Engineering Curriculum","The increasing complexity entailed in training engineers for the Industry 4.0 workplace requires an approach beyond simply cramming more into the curriculum. The purpose of this paper is to problematise the relationship between layers of engineering that constitute the multidisciplinary systems which require contextualised and responsive engagement with data. Using a number of social realist analytical instruments, the forms of knowledge and related practices at different levels within the ‘smart engineering’ curriculum are interrogated and subsequently illustrated so as to guide pedagogic decisions. The intention of the research is primarily to enable students to effectively develop 1) integrated systems-level thinking, and 2) appropriate, interpretative data processing skills. There is a symbiotic and analogical relationship between the design of a curricular framework for the ‘smart engineer’ and the collaborative, interdisciplinary research approach: drawing on multiple perspectives and approaches from the hard and soft sciences enables a more informed educational design process.",1,https://api.osf.io/v2/files/5cc297d3e6878600171416d0/,230,https://engrxiv.org/nbh6c/,10.31224/osf.io/nbh6c,,2019-04-26T12:48:16.795916,2019-04-28T01:52:43.620183 | |
| v2afr,"Elaboration of thematic maps as a tool to support urban pavement management","Considering the fact that the pavement condition of municipal roads has considerable influence on urban mobility, appropriate management of this structure is necessary and requires a significant amount of financial resources and labour. The visualization of the pavement condition on thematic maps can optimize decision making and resource allocation. Thus, this work has as its main objective to elaborate thematic maps of the pavement condition and to evaluate the utility of these representations for allocation of investments intended to the maintenance of these structures. For that, thematic maps were created in QuantumGIS (QGIS) software, using the Value of the Surface Condition (VCS) of some sections evaluated in the city of Ribeirão Preto/SP. The results indicate that the visualization of this information through thematic representations, created in Geographic Information Systems (GIS), allow the pavement management to become more efficient, optimizing resource allocation and economizing in pavement valuation services.",1,https://api.osf.io/v2/files/5cc1bc4020c6e00018cceacd/,260,https://engrxiv.org/v2afr/,10.31224/osf.io/v2afr,,2019-04-26T00:36:59.278113,2019-04-26T00:37:27.550860 | |
| e2rtc,"Work in Progress: Aligning What We Want With What We Seek: Increasing Comprehensive Review in the Graduate Admissions Process","To improve the identification of students likely to complete a graduate degree, we sought to change our process and the way we evaluate students for admission. For this, we changed the application and review process to include an assessment of applicants’ non-cognitive variables based on Sedlacek’s work and the Fisk-Vanderbilt MS-PhD Bridge Program admissions model. In 2016, our Materials Science and Engineering (MSE) Department piloted the incorporation of these changes. Consequently, MSE increased the enrollment of women and underrepresented minority students by 19% and 57%, respectively and we will be evaluating the impact of the changes on performance metrics and completion rates over time. Ahead of this application cycle, we have made changes to the applications of more of our graduate programs in the college. Most recently, we were asked to create a plan for the university. As changes continue, we will evaluate outcomes and impact within the college and across the university over time, which we hope will inform best practices for improving completion of graduate degrees and diversity of graduate programs.",1,https://api.osf.io/v2/files/5cc07257d9de11001f8043ea/,245,https://engrxiv.org/e2rtc/,10.31224/osf.io/e2rtc,,2019-04-24T15:08:18.049432,2019-04-24T15:12:23.388375 | |
| dh3ba,"Strengthening of the Panel Zone in Steel Moment Resisting Frames","Rehabilitation and retrofitting of structures designed in accordance to standard design codes is an essential practice in structural engineering and design. For steel structures, one of the challenges is to strengthen the panel zone as well as its analysis in moment-resisting frames. In this research, investigations were undertaken to analyze the influence of the panel zone in the response of structural frames through a computational approach using ETABS software. Moment-resisting frames of six stories were studied in supposition of real panel zone, different values of rigid zone factor, different thickness of double plates, and both double plates and rigid zone factor together. The frames were analyzed, designed and validated in accordance to Iranian steel building code. The results of drift values for six stories building models were plotted. After verifying and comparing the results, the findings showed that the rigidity lead to reduction in drifts of frames and also as a result, lower rigidity will be used for high rise building and higher rigidity will be used for low rise building. In frames with story drifts more than the permitted rate, where the frames are considered as the weaker panel zone area, the story drifts can be limited by strengthening the panel zone with double plates. It should be noted that higher thickness of double plates and higher rigidity of panel zone will result in enhancement of the non-linear deformation rates in beam elements. The resulting deformations of the panel zone due to this modification can have significant influence on the elastic and inelastic behavior of the frames.",1,https://api.osf.io/v2/files/5cbf5273870f9f0017201f03/,399,https://engrxiv.org/dh3ba/,10.31224/osf.io/dh3ba,,2019-04-23T18:49:09.687736,2019-04-23T18:49:23.463568 | |
| wxhpt,"R-Selected Spacecraft","This paper introduces R-selected spacecraft as a field of study that draws from concepts in ecology, and introduces the Monarch spacecraft as a case study for a system designed in accordance with the principles of this field. The Monarch is a 2.5-gram spacecraft that is the first to trade quantity, rather than cost, for low mission risk. By taking advantage of recent technological advancements in unrelated disciplines and taking a statistical approach to mission assurance, R-selected spacecraft open the door to an entirely new paradigm in space access and exploration. This paper describes the challenges and advantages unique to gram-scale, R-selected spacecraft. It also presents a number of use cases --- involving distributed in-situ sensing and planetary science --- that are unique to spacecraft of the Monarch's diminutive size and large quantity. Results from simulated lunar impact survival tests and a case-study planetary science mission are presented and discussed, suggesting one particular use case. Video demonstrations of distributed sensing, leaderless cooperation, routing, actuation, GPS acquisition, and powering are provided in the supplementary materials to illustrate the viability of some entirely new mission concepts.",1,https://api.osf.io/v2/files/5cbdcfaea3bc970018f92bfc/,315,https://engrxiv.org/wxhpt/,10.31224/osf.io/wxhpt,,2019-04-22T14:48:10.705581,2019-08-16T15:37:08.255126 | |
| 5d3sr,"Development of a national-scale real-time Twitter data mining pipeline for social geodata on the potential impacts of flooding on communities","Social media, particularly Twitter, is increasingly used to improve resilience during extreme weather events/emergency management situations, including floods: by communicating potential risks and their impacts, and informing agencies and responders. In this paper, we developed a prototype national-scale Twitter data mining pipeline for improved stakeholder situational awareness during flooding events across Great Britain, by retrieving relevant social geodata, grounded in environmental data sources (flood warnings and river levels). With potential users we identified and addressed three research questions to develop this application, whose components constitute a modular architecture for real-time dashboards. First, polling national flood warning and river level Web data sources to obtain at-risk locations. Secondly, real-time retrieval of geotagged tweets, proximate to at-risk areas. Thirdly, filtering flood-relevant tweets with natural language processing and machine learning libraries, using word embeddings of tweets. We demonstrated the national-scale social geodata pipeline using over 420,000 georeferenced tweets obtained between 20 and 29th June 2016.",1,https://api.osf.io/v2/files/5cbda657353c58001c9f0a65/,383,https://engrxiv.org/5d3sr/,10.31224/osf.io/5d3sr,10.1016/j.envsoft.2018.11.013,2019-04-22T13:43:03.894642,2019-04-22T13:43:21.470617 | |
| w63cr,"Computational optimized finite element modelling of mechanical interaction of concrete with fiber reinforced polymer","This paper presents a computational rational model to predict the ultimate and optimized load capacity of reinforced concrete (RC) beams strengthened by a combination of longitudinal and transverse fiber reinforced polymer (FRP) composite plates/sheets (flexure and shear strengthening system). Several experimental and analytical studies on the confinement effect and failure mechanisms of fiber reinforced polymer (FRP) wrapped columns have been conducted over recent years. Although typical axial members are large-scale square/ rectangular reinforced concrete (RC) columns in practice, the majority of such studies have concentrated on the behavior of small-scale circular concrete specimens. A high performance concrete, known as polymer concrete, made up of natural aggregates and an orthophthalic polyester binder, reinforced with non-metallic bars (glass reinforced polymer) has been studied. The material is described at micro and macro level, presenting the key physical and mechanical properties using different experimental techniques. Furthermore, a full description of non-metallic bars is presented to evaluate its structural expectancies, embedded in the polymer concrete matrix. In this paper, the mechanism of mechanical interaction of smooth and lugged FRP rods with concrete is presented. A general modeling and application of various elements are demonstrated. The contact parameters are defined and the procedures of calculation and evaluation of contact parameters are introduced. The method of calibration of the calculated parameters is presented. Finally, the numerical results are obtained for different bond parameters which show a good agreement with experimental results reported in literature",1,https://api.osf.io/v2/files/5cb805573992690017132d65/,382,https://engrxiv.org/w63cr/,10.31224/osf.io/w63cr,10.12989/cac.2019.23.1.061,2019-04-18T15:44:49.027563,2019-04-18T15:58:03.508183 | |
| dr2ua,"Effects of external mechanical loading on stress generation during lithiation in Li-ion battery electrodes","Li-ion batteries are ineluctably subjected to external mechanical loading or stress gradient. Such stress can be induced in battery electrode during fabrication and under normal operation. In this paper, we develop a model for stresses generated during lithiation in the thin plate electrode considering the effects of external mechanical loading. It is found that diffusion-induced stresses are asymmetrically distributed through the thickness of plate due to the coupling effects of asymmetrically distributed external mechanical stress. At the very early stage during Li-ions insertion, the effects of the external mechanical loading is quite limited and unobvious. With the diffusion time increasing, the external mechanical loading exerts a significant influence on the evolution of stresses generated in the electrode. External compressed electrode is inclined to increase the value of stresses generated during lithiation, while external tensed electrode tends to decrease the value of stresses, and as the diffusion time increases, the effects of the external mechanical loading on the stresses generated during lithiation become more obvious.",1,https://api.osf.io/v2/files/5cb5a08b3992690017117970/,225,https://engrxiv.org/dr2ua/,10.31224/osf.io/dr2ua,10.1016/j.electacta.2015.10.097,2019-04-16T14:51:41.327198,2019-04-16T14:58:32.327891 | |
| 4avfr,"Peridynamic modeling of fracture in fiber-reinforced composites","This paper studies the effect of fiber volume fraction and fiber length on fracture behaviour of reinforced concrete structures. Cementitious material is modeled using the non-ordinary state-based peridynamic theory. The nonlocal meshfree peridynamic method unifies mechanics of continuous and discontinuous media and thus is well-suited in simulating discontinuities such as cracks compared to the traditional mesh-based finite element method. In addition, the non-ordinary state-based peridynamics enables us to incorporate classical constitutive equations and damage criterion. Furthermore, in order to incorporate fiber within the cementitious composite, a modified semi-discrete model is introduced. A two-dimensional rectangular notched model is developed to study the effect of fiber amount and fiber length on mechanical response of cementitious composite and also on damage propagation pattern. Sufficient number of simulations are performed to statistically characterize the effect of fiber reinforcement on fracture behaviour of cementitious composite structures.",1,https://api.osf.io/v2/files/5cb509ce399269001813e5a3/,364,https://engrxiv.org/4avfr/,10.31224/osf.io/4avfr,,2019-04-16T00:11:07.323777,2019-04-16T00:11:24.621159 | |
| k7sjv,"Combining grid-tied PV and intelligent water heater control to reduce the energy costs at schools in South Africa","South Africa's escalating electricity rates are increasingly diverting educational resources to utility bills. Recent advances in solar PV affordability, the advent of the smartgrid and the capacitive nature of water heaters could be combined to enable new methods for electricity cost and efficiency management without affecting user comfort. | |
| Control methods that combine excess PV energy dumping and real-time temperature-based prioritised scheduling were compared with the normally-employed thermostat control. In addition, the performance of an energy-optimising approach is compared with a peak demand optimising approach. The results show that peak demand limiting with a two-temperature thermostat provided the highest cost saving with a 30% reduction of the school's electricity cost and only a 0.2 percentage point reduction in the number of warm water events.",1,https://api.osf.io/v2/files/5cb4fb5ea3bc970017f03fa5/,333,https://engrxiv.org/k7sjv/,10.31224/osf.io/k7sjv,10.1016/j.esd.2019.03.004,2019-04-16T00:09:56.747138,2019-04-16T17:50:38.269239 | |
| zqadm,"Fracture Toughness of LixSi Alloys in Lithium Ion Battery","Fundamental understanding of the fracture toughness of the LixSi alloys is crucial for designing of Si based high-capacity and failure-resistant electrodes. In this study, molecular dynamics simulation informed continuum chemo-mechanical modelings with conservation integrals were conducted to derive fracture toughness of LixSi alloys. Our modeling results show reasonable agreement with available experimental data, revealing that the fracture toughness of LixSi alloys with low lithium concentration does not vary significantly with lithium concentration. In addition, we demonstrated that, if lithium redistribution caused by the stress gradient around crack tip needs to be considered, an appropriate chemo-mechanical path-independent J-integral should be used as the classic Rice's J-integral is path-dependent. The obtained fracture toughness of the LixSi alloys here provides guidance for the rational design of Si based electrodes, and the presented approach also sheds light for the evaluation of the fracture toughness of other energy materials at different charging/discharging levels.",1,https://api.osf.io/v2/files/5cb48e5339926900160f8384/,464,https://engrxiv.org/zqadm/,10.31224/osf.io/zqadm,,2019-04-15T14:35:40.274082,2019-09-17T12:10:42.824603 | |
| wfv2x,"POST-EVENT PLASTIC FAILURE ANALYSIS OF SHEAR FRAMES FROM THEIR PRE-EVENT ELASTIC RESPONSE","We demonstrate that plastic failure loads of shear frames can be inferred from their elastic ambient response. The interstory plastic mechanism force is derived for moment-resisting (rigid) frames as a function of two measured elastic (low-amplitude) frequencies. Structural health monitoring techniques are traditionally devised for “post-event” assessment of structures after exposure of a facility to a potentially damaging loading event such as strong earthquakes or blasts. The knowledge of induced damage, its location, and severity in an otherwise functioning | |
| structure, as important as it is, may be too late for precautionary preparations. Naturally, one is interested in identification of potential failure mechanisms and indicators prior to damaging events when a structure is responding to environmental loads elastically. Are post-event plastic failure loads identifiable from the pre-event ambient response? We answer this question by first deriving interstory shear stiffness values from a set of measured ambient frequencies that are then incorporated into post-elastic equilibrium equations for a closed-form expression of failure loads as a function of measured frequencies. We test our procedure using a typical shear frame example as proof of concept. To extend the relevance and applicability of the proposed procedure we consider uncertainties associated with the measured and estimated quantities and assess their effects in our model output. The closed-form solutions presented allow study of fully-stressed designs and we present the optimal stiffness distribution for such designs as another example. It is anticipated that temporal relevance of structural health monitoring techniques to “pre-event” assessment will be extended in the near future to such promising technologies as earthquake early warning systems.",1,https://api.osf.io/v2/files/5cb37563353c58001b9bdcff/,226,https://engrxiv.org/wfv2x/,10.31224/osf.io/wfv2x,,2019-04-15T13:34:27.266567,2019-04-15T13:35:05.666666 | |
| kaqew,"Fusion of fNIRS and EEG Signals: Mental Stress Study","Fusion of Functional Near infrared Spectroscopy (fNIRS) and Electroencephalograph (EEG) is a novel approach. This study aims in improving the detection rate of mental stress using the complementary nature of fNIRS and EEG neuroimaging modality. Simultaneous measurements of fNIRS and EEG signals were conducted on 12 subjects while solving arithmetic problems under two different conditions (control and stress). The stress in this work was based on arithmetic task difficulty, time pressure and negative feedback of individual performance. The study demonstrated significant reduction in the concentration of oxygenated hemoglobin (p=0.0032) and alpha rhythm power (p=0.0213) on the PFC under stress condition. Specifically, the right PFC and dorsolateral PFC were highly sensitive to mental stress. Using support vector machine (SVM), the mean detection rate of mental stress was calculated as 91%, 95% and 98% using fNIRS, EEG and fusion of fNIRS and EEG signals respectively.",1,https://api.osf.io/v2/files/5cb34939f2be3c0017041cc3/,317,https://engrxiv.org/kaqew/,10.31224/osf.io/kaqew,,2019-04-15T13:32:35.532412,2019-04-15T13:33:07.536615 | |
| 6a2tn,"Tomographic Processing of Synthetic Aperture Radar Signals for Enhanced Resolution","Spotlight-mode synthetic aperture radar imaging is studied from the viewpoint of tomographic signal processing which allows the relaxation of the nearly-universal assumption that plane waves pass over the ground patch. This allows high-quality image reconstruction in the face of arbitrary amounts of wavefront curvature such as would be present when the angle subtended by the ground patch, as seen by the radar, is not small. One such application is wide-area surveillance. A meth- odology is used which has the benefits of a wideband transmitted signal (impulse) and a sensible simulation. Image reconstruction algorithms are developed for monostatic and bistatic systems. Simulation results using these algorithms compare favorably with baseline simulations which use a more conventional algorithm operating on data which do not embody the effects of wavefront curvature. Comments on system design and computational implementation are made as necessary. A new set of problems which appear to benefit from the tomographic viewpoint is posed. This work may also find applications in some forms of reflection tomography.",1,https://api.osf.io/v2/files/5cb15eaa39926900181005e3/,254,https://engrxiv.org/6a2tn/,10.31224/osf.io/6a2tn,,2019-04-13T15:00:48.104524,2019-04-15T09:20:42.922019 | |
| mw9dc,"A bibliometric review of process mining in manufacturing processes","The process mining is essential when it is needed to know what is happening in the execution of the processes, even more when it is manufacturing processes. Also, there is a lack of studies on process mining in manufacturing processes, one reason is because the process mining still a young field of study. Therefore, this paper presents a bibliometric review of a history of the process mining techniques applied in manufacturing processes. It was used, as methodology, a systematic review of the literature, by consulting databases from Web of Science and Scopus, using filters to generate a sample that would match with the scope of the research. As results, it was made some analysis, which presents the identification of the years, authors, research source, countries, number of citations, keywords cloud and industry type used in the cases studied. Also, some graphics, tables and information is presented on this paper.",1,https://api.osf.io/v2/files/5cad5580e3915600165d9461/,296,https://engrxiv.org/mw9dc/,10.31224/osf.io/mw9dc,10.5380/relainep.v7i11.60934,2019-04-10T02:38:03.929330,2019-10-29T04:53:00.471196 | |
| 3p8cj,"Simple models for the operation of partially transparent radiative windows and their comparison to the radiative coolers","In this work we solve approximately the radiative heat transfer problem in one dimension to perform a comparative analysis of the time averaged performance of the partially transparent radiative windows and radiative coolers. Our physical model includes the atmosphere, the window, and the backwall that are all in the thermal equilibrium with each other, and that can exchange energy via radiative heat transfer or convection. Moreover, we use a simplified two-state model for the optical properties of an atmosphere and a window material which assumes two distinct sets of the optical reflection/absorption/transmission parameters in the visible/near-IR versus mid-IR spectral ranges. Furthermore, we have distinguished the design goals for the partially transparent windows and radiative coolers and provided optimal choice for the material parameters to realize these goals. Thus, radiative coolers are normally non-transparent in the visible, and the main goal is to design a cooler with the temperature of its dark side as low as possible compared to that of the atmosphere. For the radiative windows, however, their surfaces are necessarily partially transparent in the visible. In the cooling mode, therefore, the main question is about the maximal visible light transmission through the window at which the temperature on the window somber side does not exceed that of the atmosphere. We believe that our simple physical models complimented with an in-depth comparative analysis of the radiative windows and coolers can be of interest to a number of scientists and engineers pursuing research in these disciplines.",1,https://api.osf.io/v2/files/5cabc780404d5f0017ef0e0f/,288,https://engrxiv.org/3p8cj/,10.31224/osf.io/3p8cj,,2019-04-08T22:21:45.283158,2019-05-31T16:40:42.667824 | |
| 7v9ks,"Multilevel Assessment of Mental Stress using SVM with ECOC: An EEG Approach","Mental stress has been identified as one of the major contributing factors that leads to various diseases such as heart attack, depression and stroke. To avoid this, stress quantification is important for clinical intervention and disease prevention. This study aims to investigate the feasibility of exploiting Electroencephalography (EEG) signals to discriminate between different stress levels. We propose a new assessment protocol whereby the stress level is represented by the complexity of mental arithmetic (MA) task for example, at three levels of difficulty, and the stressors are time pressure and negative feedback. Using 18-male subjects, the experimental results showed that there were significant differences in EEG response between the control and stress conditions at different levels of MA task with p-values < 0.001. Furthermore, we found a significant reduction in alpha rhythm power from one stress level to another level, p-values <0.05. In comparison, results from self-reporting questionnaire NASA-TLX approach showed no significant differences between stress levels. In addition, we developed a discriminant analysis method based on multiclass support vector machine (SVM) with error-correcting output code (ECOC). Different stress levels were detected with an average classification accuracy of 94.79%. The Lateral Index (LI) results further showed dominant right prefrontal cortex (PFC) to mental stress (reduced alpha rhythm). The study demonstrated the feasibility of using EEG in classifying multilevel mental stress, and reported alpha rhythm power at right prefrontal cortex as a suitable index.",1,https://api.osf.io/v2/files/5cab62fd08a3bf001903ff0d/,372,https://engrxiv.org/7v9ks/,10.31224/osf.io/7v9ks,,2019-04-08T15:06:27.941080,2019-04-09T13:24:36.322376 | |
| 2qb6r,"Design of an Optimized Inlet Shroud for a Flanged Diffuser","Numerical simulation using commercial CFD package ANSYS Fluent ® is carried out for a horizontal axis wind turbine with a flanged diffuser. An optimized inlet shape that further accelerates the flow through the diffuser has been proposed and evaluated. The principle behind the increase in mass flow rate due to the shape of the inlet shroud has been discussed, with emphasis on the modelling techniques presented. The low static pressure aft of the flange at the exit periphery induces a greater mass flow through the diffuser, thereby resulting in a higher capacity factor of the enclosed wind turbine. A comparison between different inlet shroud configurations has also been presented.",1,https://api.osf.io/v2/files/5caafcb5641d10001bbf5626/,282,https://engrxiv.org/2qb6r/,10.31224/osf.io/2qb6r,,2019-04-08T07:50:31.434136,2019-06-14T21:28:50.817666 | |
| cq9s3,"Immobilization of cobalt doped rutile TiO2 on carbon nanotubes walls for efficient photodegradation of 2,4-dichlorophenol under visible light","In this work, we focused on improvement of rutile-type TiO2 degradation efficiency by cobalt doping and decorating on carbon nanotubes walls (CNTs) (Co-TiO2/CNTs). X-ray diffraction (XRD), energy dispersive X-ray spectroscopy (EDX), field emission scanning electron microscopy (FESEM), diffuse reflectance spectroscopy (DRS), and nitrogen physisorption were used to characterize the prepared samples. The XRD results indicated after cobalt doping, we obtained rutile phase as the major phase for cobalt containing samples. The band gap energy of the synthesized samples were calculated by Kubelka-Munk equation using diffuse reflectance spectra. The surface area of the samples was obtained by BET model and average pore diameter and pore volume of the samples were extracted from desorption branch of BJH model. The effectiveness of the samples was examined through degradation of 2,4-dichlorophenol (2,4-DCP) as a model of organic pollutants under visible light. We achieved 27% and 50% visible light degradation of 2,4-DCP in the presence of pure TiO2 and Co-TiO2/CNTs after 180 min irradiation, respectively. The high visible light activity of Co-TiO2/CNTs sample can be approved that the presence of cobalt and CNTs reduce the band gap energy and sensitize TiO2 surface to visible light respectively. The mechanism for degradation of 2,4-DCP by Co-TiO2/CNTs photocatalyst under visible light is proposed.",1,https://api.osf.io/v2/files/5caaca1cdf977b0018f56087/,271,https://engrxiv.org/cq9s3/,10.31224/osf.io/cq9s3,,2019-04-08T04:25:58.901154,2019-04-09T13:29:41.168930 | |
| um762,"Quantification of Mental Stress using fNIRS Signals","In this study, we propose functional near infrared spectroscopy (fNIRS) to objectively grade different levels of mental stress. The levels of stress were set based on arithmetic task difficulty, time pressure and negative feedback about peer performance. We examined the proposed approach on twelve human subjects using the Montreal Imaging Stress Task. The experiment results revealed a reduction in cortical activations at prefrontal cortex when stressed, and the differences in hemodynamic response between control condition and under stress were significant with mean p-values of 0.0023, 0.00015 and 0.0004 for arithmetic difficulty level one, two and three, respectively. We thus confirm the feasibility of fNIRS in grading mental stress.",1,https://api.osf.io/v2/files/5caa47282aa0d90017d293ab/,292,https://engrxiv.org/um762/,10.31224/osf.io/um762,,2019-04-07T18:55:39.307999,2019-04-09T13:30:10.998109 | |
| ygxau,"Explicit Stencil Computation Schemes Generated by Poisson's Formula for the 2D Wave Equation","An approach to building explicit time-marching stencil computation schemes for the transient 2D acoustic wave equation without using finite-difference approximations is proposed and implemented. It is based on using the integral representation formula (Poisson's formula) that provides the exact solution of the initial-value problem for the transient 2D scalar wave equation at any time point through the initial conditions. For the purpose of constructing a two-step time-marching algorithm, a modified integral representation formula involving three time levels is also employed. It is shown that integrals in the two representation formulas are exactly calculated if the initial conditions and the sought solution at each time level as functions of spatial coordinates are approximated by stencil interpolation polynomials in the neighborhood of any point in a 2D Cartesian grid. As a result, if a uniform time grid is chosen, the proposed time-marching algorithm consists of two numerical procedures: 1) the solution calculation at the first time-step through the initial conditions; 2) the solution calculation at the second and next time-steps using a generated two-step numerical scheme. | |
| Three particular explicit stencil schemes (with five, nine and 13 space points) are built using the proposed approach. Their stability regions are presented. The obtained stencil expressions are compared with the corresponding finite-difference schemes available in the literature. Their novelty features are discussed. Simulation results with new and conventional schemes are presented for two benchmark problems that have exact solutions. It is demonstrated that using the new first time-step calculation procedure instead of the conventional one can provide a significant improvement of accuracy even for later time steps.",1,https://api.osf.io/v2/files/5ca7642033122500188ff936/,250,https://engrxiv.org/ygxau/,10.31224/osf.io/ygxau,,2019-04-05T14:47:45.060301,2019-05-21T13:04:24.636660 | |
| 94wfg,"Energy perceptions in South Africa: An analysis of behaviour and understanding of electric water heaters","Using data from an online national survey conducted in South Africa, this paper aims to investigate: the awareness of energy savings measures for electric water heaters (EWHs); whether or not consumers are implementing suggested measures; and if consumers understand and effectively control their EWHs’ energy usage. Additionally, the data is used to determine the success of educational and rebate programmes aimed at reducing residential energy usage and to determine possible motivations for encouraging users to reduce or alter their EWH energy and warm water consumption. The results of this questionnaire indicate that: convenience is a key factor in consumers’ willingness to implement curtailment actions; users don’t understand the energy consumption of their EWHs; and they don’t know how to control their EWHs efficiently.",1,https://api.osf.io/v2/files/5ca54597c25afd001cdeb20b/,264,https://engrxiv.org/94wfg/,10.31224/osf.io/94wfg,10.1016/j.esd.2016.03.006,2019-04-03T23:48:49.998476,2019-04-04T18:27:33.991453 | |
| v83k5,"Impacts of Engineering Justice Curriculum: A Survey of Student Attitudes","As part of a larger project examining the role of humanitarian service learning in engineering (NSF project number EEC-1540301), we conducted an investigation of first-year engineering students' perceptions of humanitarian service learning projects, social responsibility in their discipline, and ethics in STEM. Students (n=231) taking a required freshmen level engineering course were surveyed with a pre- and post-instrument, and provided with these working definitions: | |
| * Community Service is voluntary work intended to help people in a particular community. | |
| * Social Responsibility is an obligation that an individual (or company) has to act with concern and sensitivity, aware of the impacts of their own action on others, particularly the disadvantaged. | |
| * Social Justice relates to the distribution of the advantages and disadvantages in society, including the way in which they are allocated. | |
| * Pro bono- work done without compensation (pay) for the public good. | |
| This course specifically addresses the issues described above with the goal of providing early exposure to topics that will be reinforced in non-major coursework, such as general education elective courses. Results showed that there was little change in student perceptions before and after completion of the course in terms of their perceptions of ethics, social responsibility, and social justice. In the areas in which there were statistically significant changes, students were, on average, slightly less sure the engineering profession can help people or solve social issues and slightly less interested in a job that involves helping people. On the other hand, students were slightly more aware, after the course, of the need to include social aspects in engineering practice and rated technical and professional skills as slightly less important after the class. It was also found that some groups in the class (women, minority students, first-generation students, and student less focused on salary in thinking about their future jobs) entered the class with different attitudes and changed in different ways by the end of the course. Overall, the results of this survey support other findings in engineering ethics which suggests that one course is insufficient to make significant impacts on the ways engineering students think about the societal implications of their work. However, these declines in student confidence, while small, are important to take seriously and this paper will draw out potential implications of this finding. Finally, we will discuss the implications of the differences within the class in terms of effective teaching of these topics and retention of underrepresented students.",1,https://api.osf.io/v2/files/5ca4ce1cf77305001a3b576f/,264,https://engrxiv.org/v83k5/,10.31224/osf.io/v83k5,,2019-04-03T15:20:12.092736,2019-04-03T18:03:47.983228 | |
| 85svm,"A peridynamic model for damage and fracture in porous materials","(This paper is submitted to ""International Journal of Rock Mechanics and Mining Sciences"") We introduce a peridynamic (PD) model for simulating damage and fracture in porous materials based on an Intermediate Homogenization (IH) approach. In this approach, instead of explicitly representing the detailed pore geometry, we use homogenization but maintain some information about the microstructure (porosity) in the model. Porosity is introduced in the model as initial peridynamic damage, implemented by stochastically pre-breaking peridynamic bonds to match the desired porosity value. We validate the model for elastodynamics with wave propagation in porous glasses, where we match observed wave propagation speeds and the apparent elastic moduli for various porosities. The model is then used to study the fracture behavior of Berea sandstone under three-point bending loading conditions. We validate the model for fracture problems using the case of failure in a sandstone sample with an off-center pre-notch under three-point bending. The IH-PD results agree very well with experiments: we obtain different failure modes depending on the length of the off-center pre-notch. When the pre-notch is short, most damage (and the subsequent failure) happens in the center of the beam (largest tensile stresses in an un-notched sample). In this case, material porosity makes the fracture behavior “insensitive” to the presence of the off-center pre-notch. When the pre-notch is long, damage starts from near its tip, and progresses in mixed mode towards the loading point. The model captures the location of crack initiation to be the right-corner of the notch, exactly as shown by the experimental acoustic emission results. A fully-homogenized model for the porous sandstone fails to reproduce the failure mode sensitivity on the pre-notch length. The results show the importance of using the IH-PD model when trying to capture the important effects local heterogeneities (like pores) have on damage initiation and growth in porous materials.",1,https://api.osf.io/v2/files/5ca401e4c25afd001cdde63d/,720,https://engrxiv.org/85svm/,10.31224/osf.io/85svm,,2019-04-03T00:53:57.619507,2019-04-05T00:57:00.209401 | |
| gz3db,"The Effect of Working Fluids on Premixed Hydrogen Combustion in a Constant Volume Combustion Chamber","Premixed combustion of hydrogen was investigated with the purpose of examining the effect of the full or partial substitution of argon for nitrogen in air on laminar burning velocity. Theoretically, this partial replacement decreases the NOx emissions and increases the thermal efficiency of internal combustion engines due to the high specific heat ratio of noble gases. An optically-accessible constant volume combustion chamber (CVCC) with central ignition was used to study flame propagation, flame morphological structure, and instability. The spherical flame development was studied using a high-speed Z-type Schlieren visualization system. Moreover, a numerical model was developed to convert the pressure rise data to laminar burning velocity. Coupling the model to a chemical equilibrium code aids in determining the burned gas properties. The experimental and numerical investigations indicate that increasing the concentration of argon as the working fluid in the mixture can increase the laminar burning velocity and extend the lean flammability limit.",1,https://api.osf.io/v2/files/5ca2546705597c001ae1bf10/,362,https://engrxiv.org/gz3db/,10.31224/osf.io/gz3db,,2019-04-01T18:14:18.990028,2019-08-05T17:50:48.371741 | |
| ebvah,"Numerical Study on Direct Injection of Hydrogen-Methane Blends into a Constant Volume Combustion Chamber","Natural gas is not commonly used in compression ignition cycles due to difficulty in achieving autoignition conditions. The addition of hydrogen to natural gas can help overcome this issue considering hydrogen’s flammability range and ability to autoignite. In this computational study, the turbulent injection of hydrogen-methane mixtures with varied composition of the gaseous fuels into a constant volume combustion chamber has been modeled. All conditions including injection pressure, initial chamber temperature, and initial chamber pressure are kept constant; the jet properties and combustion characteristics were then investigated. The results indicate that adding hydrogen to methane drastically shortens the ignition delay, enables the system to run at a lower initial temperature, and provides appropriate conditions for the compression ignition of the gaseous fuel. Increasing the volume fraction of hydrogen in the mixture strongly affects the spray tip penetration length and cone angle, while altering the mixing rate of the injected fuel with air. The mixtures with higher hydrogen volume fractions penetrate more during the early stages of injection. However, the higher momentum of the mixtures with more methane compensates for this effect when the jet disperses significantly in the chamber.",1,https://api.osf.io/v2/files/5ca252de0a13d7001a8b895b/,393,https://engrxiv.org/ebvah/,10.31224/osf.io/ebvah,,2019-04-01T18:08:53.486186,2019-04-11T18:12:36.387796 | |
| gdzcw,"Assessment of Mental Stress Using EEG and fNIRS Features","Stress is a major contributing factor to chronical disorders and productivity loss. Students spend most of their time studying, often burdened with high workloads and time pressure, a factors that contribute to increase the level of stress and decrease their academic performance. Stress activates the hypothalamus-pituitary-adrenocortical axis and the sympathetic nervous system leading to the release of stress hormone (cortisol) in the adrenal cortex. The continuous release of cortisol leads to several chronical diseases including anxiety, depression, stroke and even addiction. Therefore, an accurate stress detection method at its early stage is very important to clinical intervention, diseases prevention as well as for academic performance. While different neuroimaging modalities have been proposed to detect mental stress, each modality experiences certain limitations. Neuroimaging tools such as functional magnetic resonance imaging (fMRI) and positron emission tomography (PET) have good spatial resolution, yet are limited in terms of temporal resolution and susceptibility to motion artifacts. They also require the test subjects to remain at fixed position during scanning. Electroencephalography (EEG) constitutes a possible alternative neuroimaging technique that does not possess the same limitations. The EEG has temporal resolution in the order of a few milliseconds, which makes it suitable for measuring cortical changes during workplace activities. However, the EEG is generally considered as having poor spatial resolution (compare to excellent fMRI modality) and being highly prone to motion artifacts. Functional near-infrared spectroscopy (fNIRS) has allowed human cortical activity to be measured during unconstrained movements, the temporal resolution is sub-second, and the spatial resolution is on order of 1 cm2 at best. In order to overcome these constraints, it is advisable to combine the EEG with fNIRS modality to provide a complementary nature and improve the detection rate of mental stress.",1,https://api.osf.io/v2/files/5ca22fc0ecd788001798e27c/,352,https://engrxiv.org/gdzcw/,10.31224/osf.io/gdzcw,,2019-04-01T15:42:05.094465,2019-04-01T15:49:04.355673 | |
| m4yrd,"Wood defect detection using low acoustic impedance-based PZT transducers","Early detection of common defects in wooden structures is an important factor to avoid costly maintenance and improve the life expectancy of structures. A novel qualitative technique has been developed and evaluated for detecting near-surface abnormalities and defects in wooden structures. The proposed setup consisted of a piezoelectric ceramic lead-zirconate-titanate (PZT) transducer and an impedance evaluation board. This setup is cost-effective and can be easily employed over various wooden structures. The proposed setup was evaluated on a polymeric material with a debonding. The main experimental validations were conducted on wood specimens with unfilled carved cavities and also, putty-filled holes. In addition, the setup was tested for the poor gluing in a wooden specimen. The measured impedance for each location was recorded and normalized to the reference baseline. The proposed setup could detect the cavities and putty-filled regions successfully. It also could detect the approximate geometry of defects. The glued and unglued regions were detected as well.",1,https://api.osf.io/v2/files/5ca21b0908f52b00185b1409/,271,https://engrxiv.org/m4yrd/,10.31224/osf.io/m4yrd,,2019-04-01T14:15:51.440406,2019-09-11T17:07:37.038315 | |
| jg27s,"The shear buckling and postbuckling behavior of laterally pressured curved panels","Curved panels are widely used in different structures from fuselage of planes to curved bridge girders. An accurate understanding of buckling and postbuckling behavior of curved panels under different loadings is essential for efficient structural design. The shear buckling and postbuckling behavior of laterally pressured thin curved panels under gradually increasing in-plane shear forces is investigated. The magnitude of the lateral forces, the radius of curvature and the aspect ratio of panels are considered in the parametric studies. A classic theoretical formulation of curved panels buckling load is reexamined and compared to experimental results. The results showed that inward pressure eliminates the snap-through phenomenon and the softening stage in the response of shallow curved panels. However, the buckling characteristics are not significantly affected in the moderately curved panels under small pressures. In addition, the magnitude of inward pressures that would affect the shear buckling and postbuckling behavior of panels depends on their radius of curvature. The ultimate shear capacity of a highly curved panel is considerably reduced due to the increasing presence of inward pressures. The failure mode of highly curved panels are associated with the occurrence of unstable buckling; and as a result, the released strain energy prevents the occurrence of hardening stages.",1,https://api.osf.io/v2/files/5c9e2eec06cd47001a5a7bbd/,273,https://engrxiv.org/jg27s/,10.31224/osf.io/jg27s,,2019-03-29T14:53:30.286540,2019-04-11T18:24:23.491246 | |
| 7ypmk,"Study of the Adhesion Mechanism of Acidithiobacillus ferrooxidans to Pyrite in Fresh and Saline Water","In the present work electrostatic forces are evaluated as the cause of attachment of Acidithiobacillus ferrooxidans to pyrite. Streaming potential of A. ferrooxidans and pyrite was measured in two environment, fresh water and saline water (water with 35 g/L of NaCl) at different pH's values. At the same time, attachment kinetics of A. ferrooxidans to pyrite were carried out in fresh and saline water at pH 4. The results showed that A. ferrooxidans and pyrite present lower streaming potential (comparing absolute values) in saline water than in fresh water, indicating the compression in the electric double layer caused by Cl- and Na+ ions. Simultaneously, it was determined that the bacteria present a higher attachment to pyrite in fresh water than in saline water. This suggests that electrostatics forces do not play a leading role in the adhesion mechanism.",1,https://api.osf.io/v2/files/5c9d40d5246078001aff2543/,274,https://engrxiv.org/7ypmk/,10.31224/osf.io/7ypmk,,2019-03-28T21:50:12.222541,2019-03-29T00:04:49.343764 | |
| gpsm2,"Attachment of Acidithiobacillus ferrooxidans to pyrite in fresh and saline water and its fitting to Langmuir and Freundlich isotherms","Attachment of bacteria Acidithiobacillus ferrooxidans to pyrite was investigated in two different environment: fresh water and saline water (water with 35 g/L of NaCl), in both cases at pH 4. Adsorption isotherms were ?tted to the Langmuir and Freundlich models. The results showed that the bacteria adhere to pyrite to a greater extent in fresh water than in saline water. The Langmuir and Freundlich models ?tted well the data obtained in fresh water, showing a coeffcient of determination (R2) approximately equal to 0.8 for both models. On the other hand, in saline water the models did not show a good coeffcient of determination with a value approximately equal to 0.4 for both models.",1,https://api.osf.io/v2/files/5c9d3effe0a7de0019952285/,283,https://engrxiv.org/gpsm2/,10.31224/osf.io/gpsm2,,2019-03-28T21:45:00.610946,2019-03-29T13:52:07.451051 | |
| 9cb4d,"Auditory intelligent speed adaptation for long–distance informal public transport in South Africa","Informal transport refers to the collective passenger | |
| road transport industry with little or no regulatory control of its operations, usually characterised by unplanned and ad-hoc service delivery. The notoriously dangerous informal transport industry in South Africa – dominated by minibus taxis – has been shown to disregard the posted speed limit on long-distance trips. Not only do they frequently exceed the differentiated speed limit imposed on minibus taxis, but also the speed limit imposed on normal passenger vehicles. This paper evaluates the impact of an auditory Intelligent Speed Adaptation (ISA) intervention, applied at various intensity levels, on the speeding behaviour of this seemingly intransigent mode of transport. The experiment evaluates the behaviour on the R61 between Beaufort West and Aberdeen. We evaluate the speeding distributions, speeding frequencies, speed percentiles, mean speeds, and the statistical relevance of key metrics. We find that the auditory intervention has a clear impact on speeding behaviour, both when applied | |
| at an audible level that can be drowned out by a radio, and | |
| even greater impact at a loud level. The impact on speeding | |
| is significant, with speeding frequency (both time and distance) reducing by over 20 percentage points.",1,https://api.osf.io/v2/files/5c9c80c2e0a7de0019949130/,245,https://engrxiv.org/9cb4d/,10.31224/osf.io/9cb4d,10.1109/MITS.2016.2533979,2019-03-28T08:12:02.187098,2019-03-28T13:12:47.348796 | |
| 6n5fs,"Large Deflection Behavior Effect in Reinforced Concrete Columns Exposed to Extreme Dynamic Loads","Reinforced concretes (RC) have been widely used in constructions. In construction, one of the critical elements carrying a high percentage of the weight is columns which were not used to design to absorb large dynamic load like surface bursts. This study focuses on investigating blast load parameters to design more resistant RC columns to blast loads. The numerical model is based on finite element analysis (FEA) using LS-DYNA. Numerical results are validated against blast field tests available online. Couples of simulations are performed with changing blast parameters to study effects of various scaled distances on the nonlinear behavior of RC columns. According to simulation results, the scaled distance has a substantial impact on the blast response of RC columns. With lower scaled distance, higher peak pressure and larger pressure impulse are applied on the RC column. Eventually, keeping the scaled distance unchanged, increasing the charge weight or shorter standoff distance cause more damage to the RC column. Intensive studies are carried out to investigate the effects of scaled distance and charge weight on the damage degree and residual axial load carrying capacity of RC columns with various column width, longitudinal reinforcement ratio and concrete strength. Results of this research will be used to assessment the effect of an explosion on the dynamic behavior of RC columns.",1,https://api.osf.io/v2/files/5c9a265bf718460019b44f72/,254,https://engrxiv.org/6n5fs/,10.31224/osf.io/6n5fs,,2019-03-26T14:19:57.629309,2019-07-24T23:36:15.419058 | |
| ehrdj,"Original Title: On value and using of TAWS/FMS alert data in examination of air accidents, the case of Warsaw-Smolensk flight on 10 April 2010. Polish Title: O wartości i wykorzystaniu danych TAWS/FMS do badania wypadków lotniczych, sprawa lotu Warszawa-Smoleńsk, 10 kwietnia 2010 roku","Through an analysis of TAWS/FMS data collected and registered during the last minute of TU-154M aircraft flight from Warsaw to Smolensk, we show the value and existence of space for undertaking research works on enhancing standard functionality of TAWS/FMS systems to enable their effective use in examination of the course and causes of air accidents. The flight ended up in the total destruction of the aircraft and the death of all passengers and crew on board. The TAWS/FMS flight altitudes and spatio-temporal data, i.e. geographical location and speed of the aircraft motion, were inspected for their internal and external consistency with the data from the ATM QAR service recorder. Using the data from ATM QAR, records from the cockpit voice recorder (CVR), jointly with data from the TAWS/FMS systems, it was possible to reconstruct the most probable horizontal and vertical trajectory of the TU- 154M aircraft during the last minute of flight before its complete destruction, as well as the likely scenario of accompanying events. The data available from recorders enabled the authors to gain information on the preliminary stage of the course of accident, and the first phase of the aircraft’s destruction, resulting in serious damage of the left wing of the aircraft. Enhanced standard functionality of TAWS/FMS systems, incorporating use of their data in the post-accident situations examination, would have improved results and simplified the present analysis considerably.",1,https://api.osf.io/v2/files/5c993bc0f718460019b3ebd5/,279,https://engrxiv.org/ehrdj/,10.31224/osf.io/ehrdj,,2019-03-26T13:46:56.242709,2019-07-24T23:36:08.982480 | |
| p65f9,"A dynamical multi-input/multi-output network formulation for stability analysis in AC microgrids","Nowadays, we have witnessed a significant increase | |
| of renewable sources across the existing power grids, as a | |
| result of the undeniable need to mitigate the effects of environmental pollution and assist the economic development of countries around the globe. However, due to the lack of rotational inertia and their intermittent nature, renewables have also increased the severity of the occurring disturbances and instability phenomena, which in turn place a demand for more accurate modeling of the network and the power system components. In this paper, we propose a novel network formulation for AC microgrids that allows the consideration of less conservative conditions for the network, while allowing the adoption of higher order inverter-based generation dynamics | |
| and facilitating the stability analysis and control. In particular, we formulate the network as a dynamical multi-input/multi-output system, which we show is both stable and passive, even if the network’s dynamic and lossy nature is taken into account. We then briefly discuss the opportunities and the advantages offered by the proposed approach and provide useful guidelines for a more accurate modeling of power system components. | |
| Finally, we verify the proposed network formulation through a numerical application on the Four Machine Two Area Kundur test system and several simulations on typical Medium Voltage (MV) distribution lines.",1,https://api.osf.io/v2/files/5c99166cf718460019b3d875/,240,https://engrxiv.org/p65f9/,10.31224/osf.io/p65f9,,2019-03-25T18:05:00.496956,2019-07-24T23:36:11.929397 | |
| tymhs,"A Stochastic Homogenized Peridynamic Model for Intraply Fracture in Fiber-Reinforced Composites","The quasi-static transverse fracture behavior in unidirectional fiber-reinforced composites (FRCs) is investigated using a new intermediately-homogenized peridynamic (IH-PD) model and a fully homogenized peridynamic (FH-PD) model. The novelty in the IH-PD model here is accounting for the topology of the fiber-phase in the transverse sample loading via a calibration to the Halpin-Tsai model. Both models can capture well the measured load-displacement behavior observed experimentally for intraply fracture, without the need for an explicit representation of microstructure geometry of the FRC. The IH-PD model, however, is more accurate and produces crack path tortuosity as well as a non-monotonic load-crack-opening softening curve, similar to what is observed experimentally. These benefits come from the preservation of some micro-scale heterogeneity, stochastically generated in the IH-PD model to match the composite’s fiber volume fraction, while its computational cost is equivalent to that of an FH-PD model. We also present a three-point bending transverse loading case in which the two models lead to dramatically different failure modes: the FH-PD model shows that failure always starts from the off-center pre-notch, while the IH-PD model, when the pre-notch is sufficiently off-center, finds that the composite fails from the center of the sample, not from the pre-notch. Experiments that can confirm these findings are sought.",1,https://api.osf.io/v2/files/5c95c1e374462c0016ad5f61/,491,https://engrxiv.org/tymhs/,10.31224/osf.io/tymhs,10.1016/j.compscitech.2019.107770,2019-03-23T05:31:22.667605,2019-10-13T14:16:52.829038 | |
| 486jh,"Turbulent theory of velocity-profile-induced jet breakup","Velocity profile relaxation is commonly believed to be a cause of jet breakup. This claim is critically reevaluated in this work. Contrary to common belief, laminar liquid jets with parabolic velocity profiles are actually more stable than laminar jets with flatter velocity profiles. This is shown using prior theory and experiments. For turbulent jets, the influence of the velocity profile is more difficult to determine. Previous experimentalists claimed to show that the velocity profile has an effect by varying the nozzle length. The claim is that the boundary layer thickness grows with nozzle length, and that the larger the boundary layer, the less stable the jet. In this work, nozzle length is shown to be a poor proxy for velocity profile effects because the turbulence intensity also increases as the nozzle length increases. Studies with this confounding were ignored in this work. Thinner boundary layers have greater shear, yet experiments have shown that if the boundary layer were made thinner (all else constant), the jet often is more stable. This is termed the ""shear paradox"". A potential resolution to the shear paradox is developed by considering that the area with shear also decreases as the boundary layer thickness is decreased, and by non-dimensionalizing the turbulent production rate by the dissipation. This theory shows an interaction between the integral scale and velocity profile relaxation which has not been previously discussed. The theoretical prediction that a smaller integral scale leads to more stable jets (due to increased turbulent dissipation) is shown to be somewhat consistent with the limited experimental and DNS data available.",1,https://api.osf.io/v2/files/5c9558807d67be0016711f2c/,378,https://engrxiv.org/486jh/,10.31224/osf.io/486jh,,2019-03-22T21:52:14.446559,2019-03-22T23:57:44.814450 | |
| k2fnm,"Improving the validation of turbulent jet breakup models","Understanding the physics of the breakup of turbulent liquid jets is important for a variety of applications including engine sprays, fire suppression systems, and water jet cutting. Models of turbulent jet breakup allow predictions of quantities of interest like the droplet size distribution and breakup length of the jet. These models are compared against experimental data in a process called validation. If the model predictions are within the experimental uncertainty, then the model is ""validated"" and believed to be accurate, and possibly can explain the physics. Uncertainty quantification is necessary for model validation. While unfortunately relatively few experimental studies quantify uncertainty, that is not the most pressing validation issue in turbulent jet breakup. I detail 3 additional problems that can make the apparent validation of a model actually an illusion, regardless of how well the model appears to match the data. These problems include: 1. important variables being omitted or guessed in experiments and models, 2. confounding between independent variables, that is, two variables changing simultaneously, making determining cause and effect impossible, and 3. testing only combinations of submodels and not each submodel in isolation. To avoid these problems and others, I developed validation guidelines that are detailed in this work. Following these guidelines, I compiled a large experimental database. Only 28 out of 47 experimental studies considered met my data quality guidelines. Only 18 studies had quantified uncertainty, and only 3 studies had substantial variation in the turbulence intensity.",1,https://api.osf.io/v2/files/5c95534f7d67be0017710d6e/,313,https://engrxiv.org/k2fnm/,10.31224/osf.io/k2fnm,,2019-03-22T21:32:17.665936,2019-03-29T02:34:11.663629 | |
| fs3qk,"Efficient Production of Acetic Acid from Nipa (Nypa fruticans) Sap by Moorella thermoacetica (f. Clostridium thermoaceticum)","To valorize the underutilized nipa sap composed mainly of sucrose, glucose and fructose, acetic acid fermentation by Moorella thermoacetica was explored. Given that M. thermoacetica cannot directly metabolize sucrose, we evaluated various catalysts for the hydrolysis of this material. Oxalic acid and invertase exhibited high levels of activity towards the hydrolysis of the sucrose in nipa sap to glucose and fructose. Although these two methods consumed similar levels of energy for the hydrolysis of sucrose, oxalic acid was found to be more cost-effective. Nipa saps hydrolyzed by these two catalysts were also fermented by M. thermoacetica. The results revealed that the two hydrolyzed sap mixtures gave 10.0 g/L of acetic acid from the 10.2 g/L of substrate sugars in nipa sap. Notably, the results showed that the oxalic acid catalyst was also fermented to acetic acid, which avoided the need to remove the catalyst from the product stream. Taken together, these results show that oxalic acid hydrolysis is superior to enzymatic hydrolysis for the pretreatment of nipa sap. The acetic acid yield achieved in this study corresponds to a conversion efficiency of 98%, which is about 3.6 times higher than that achieved using the traditional methods. The process developed in this study therefore has high potential as a green biorefinery process for the efficient conversion of sucrose-containing nipa sap to bio-derived acetic acid.",1,https://api.osf.io/v2/files/5c94531eb239680018170e20/,335,https://engrxiv.org/fs3qk/,10.31224/osf.io/fs3qk,,2019-03-22T03:17:41.656570,2019-03-22T13:45:10.348303 | |
| tygv4,"PULSE JET INTERNAL COMBUSTION ENGINE","This article describes using the pulse jet to create circular motion. Such an engine would be highly efficient, simple and cheap to build, light weight, and could use a wide variety of liquid fuels. Such a pulse jet engine would be a very efficient substitute for the piston engine.",1,https://api.osf.io/v2/files/5c944a87b23968001916dd93/,441,https://engrxiv.org/tygv4/,10.31224/osf.io/tygv4,,2019-03-22T03:00:02.410638,2019-03-22T13:43:18.543223 | |
| bfjn3,"Estimation of component-wise drag coefficient and Planform Visualization of CG for Various Sub Components","The aim of this report, is to present an application of the preliminary design procedure followed in the course entitled “Airplane design(Aerodynamic)”. A 150 seater jet airplane cruising at M = 0.8, at 11 km altitude and having a gross still air range(GSAR) of 4000 km is considered.",1,https://api.osf.io/v2/files/5c929e9d2286e80017c86a6f/,279,https://engrxiv.org/bfjn3/,10.31224/osf.io/bfjn3,,2019-03-20T20:13:50.932420,2019-09-22T15:08:09.963382 | |
| ecxpv,"Development of Flight Envelope of a Twin Turboprop Aircraft (ATR-72)","The ATR 72 is a twin-engine turboprop, short-haul regional airliner developed and produced in France and Italy by aircraft manufacturer ATR (Aerei da Trasporto Regionale or Avions de transport régional), a joint venture formed by French aerospace company Aérospatiale (now Airbus) and Italian aviation conglomerate Aeritalia (now Leonardo S.p.A.). The number ""72"" in its name is derived from the aircraft's standard seating configuration in a passenger-carrying configuration, which could seat 72–78 passengers in a single-class arrangement.",1,https://api.osf.io/v2/files/5c929dd02286e80016c552aa/,245,https://engrxiv.org/ecxpv/,10.31224/osf.io/ecxpv,,2019-03-20T20:10:50.361928,2019-09-29T22:23:44.376916 | |
| jzdpq,"Behavior of steel storage pallet racking connection - A review","Steel pallet racking industry has globally used from the industrial revolution and has deeply evolved from hot-rolled profile into cold-formed profile to raise the optimization in engineering field. Nowadays, some studies regarding cold-formed steel profile have been performed, but fewer studies in terms of cold-formed pallet racking specifically in connection due to the semi-rigid behavior by lug-hooked into the upright have been conducted. The objective of this study is to review the related literature on steel storage racking connection behavior.",1,https://api.osf.io/v2/files/5c9050392286e80017c499c0/,584,https://engrxiv.org/jzdpq/,10.31224/osf.io/jzdpq,10.12989/scs.2019.30.5.457,2019-03-19T02:30:13.402554,2019-03-19T14:06:09.765275 | |
| muj72,"Impact damage detection in fiberglass composites using low acoustic impedance-based PZT transducers","The objective of this work is to evaluate the ability of a lead-zirconate-titanate (PZT) transducer to detect the damages caused by the impacts in fiberglass-epoxy composites. Impacts were created by a hammer (unquantified energy) and an automatic impact system (quantified energy) in multiple composite sheets. The mechanism of damage detection relies on the impedance measurement by a low acoustic impedance (LAI) transducer which resonates in the radial mode rather than the regular thickness mode. The effect of surface roughness was investigated by making specimens with different quantified surface roughness values. It was shown that the surface roughness and boundary conditions are affecting the results of the experiments in the case of very rough surface and hard boundary conditions. The main body of this study was testing the setup on the composite sheets. The specimens were tested for an energy range of 10 to 54 joules. The surface of each specimen was gridded with a step size of 5 mm and the impedance was measured for each location. The results were normalized versus to a situation that the transducer was not in contact with any load. It was shown that the proposed portable and easy-to-use LAI setup could detect the damages qualitatively. The normalized measured impedance was variable, but it showed a significant increase, in some cases as high as 100%, on the impact’s region.",1,https://api.osf.io/v2/files/5c8ec8c618184e0016c378da/,252,https://engrxiv.org/muj72/,10.31224/osf.io/muj72,,2019-03-18T20:00:15.217257,2019-09-11T16:24:54.794874 | |
| cdx6b,"Lattice Boltzmann Method to Analyse Fluid Flow Around a Circular Cylinder","An overview of the Lattice Boltzmann Method has been presented with an in house algorithm for the numerical simulation of fluid flow around a circular cylinder. The linearization of the collision operator has been discussed for distributions not close to the local equilibrium state, and numerical simulation has been carried out for stable initial conditions up to a Reynolds number of 80. An overview of the lattice gas automata with regard to Boolean variables describing the particle occupation has also been defined. A comparison between the data obtained from the two dimensional fluid flow around the cylinder and previous experimentation has also been made.",1,https://api.osf.io/v2/files/5c8c4e53075b64001ba23d8c/,331,https://engrxiv.org/cdx6b/,10.31224/osf.io/cdx6b,,2019-03-16T01:21:23.480319,2019-03-18T14:10:50.357537 | |
| 583je,"FINITE ELEMENT ANALYSES OF SUPERADOBE DOMES","This article shows Static structural analyses performed on 35 different Superadobe domed models. The dimensions of these models were defined according to a controlled variation of initial parameters, guided by previously derived equations. Maximum and Minimum principal stresses, Shear stresses and total deformations were measured assuming an idealized material with isotropic elasticity. Besides the dome’s self-weight, wind loads are considered from the most dangerous angle with respect to the openings.",1,https://api.osf.io/v2/files/5c8adf8518184e0017bee998/,228,https://engrxiv.org/583je/,10.31224/osf.io/583je,,2019-03-14T23:13:31.200361,2019-03-15T14:25:29.867736 | |
| d3em6,"APPLICATIONS OF A “GEOMETRICAL SOUNDNESS EQUATION” FOR SUPERADOBE DOMES","A Superadobe dome is a parameterization in the sense that given some initial parameters, the structure can be | |
| completely determined by them [1]. While a set of such initial parameters can produce a safe and functional structure, a different | |
| set can result in an unsafe, unstable, or even geometrically senseless structure. | |
| It is necessary for a Superadobe designer to predict the structure’s final dimensions and mechanical behavior from the initial | |
| parameters of his or her choice, so as to be able to choose them wisely. These initial independent numbers must satisfy some equations | |
| containing variables of both geometrical and mechanical nature, yet the parameters’ compliance with the single, purely-geometrical | |
| equation showcased in this article, is a necessary condition for all functional Superadobe domes. References | |
| [1] López, M. González, M. Llauradó, N. 2019. “EQUATIONS THAT DESCRIBE THE GEOMETRY OF SUPERADOBE DOMED STRUCTURES.” engrXiv. March 14. doi:10.31224/osf.io/ptq47.",1,https://api.osf.io/v2/files/5c8aca4918184e0019bee73f/,272,https://engrxiv.org/d3em6/,10.31224/osf.io/d3em6,,2019-03-14T21:45:00.267976,2019-03-15T14:24:37.201539 | |
| ptq47,"EQUATIONS THAT DESCRIBE THE GEOMETRY OF SUPERADOBE DOMED STRUCTURES","""Superadobe"" is a method for the construction of self-built shelters that has three main advantages: It’s economical, it’s easy to execute by common people, and produces buildings with good structural behavior against natural events such as earthquakes, floods, fire and high winds [1]. It consists in filling polypropylene sacks with a moist mixture of clay, sand, gravel and lime/cement; placing and compacting one on top of another in the form of concentric rings of decreasing radii and describing a double curvature monolith. (Similar to a paraboloid). | |
| The construction of these domed monoliths follow a simple geometrical pattern based on the use of compasses, hence the form, and other building characteristics can be parametric. This is, a system of equations for these building’s physical dimensions can be derived, based on initial parameters. | |
| These equation’s variables can be divided into independent ('constructive') and dependent ('observable'), and by defining the values of the independent parameters (sack dimensions, radius of base (internal compass), radius of roof (external compass), radius of skylight, dimensions of openings, mean material specific weight, mean material elastic modulus, mean friction coefficient between rows, etc.), resulting dimensions and mechanical behaviors, such as building height, interior habitable area, proportion of rows that rest upon the previous, or total building weight, maximum shear force amongst all rows, axial stresses, etc. can be determined. | |
| This article deals with the resulting geometrical dimensions of the building, given corresponding initial parameters. If we were to set some dependent variables as fixed values, we could solve the system of equations for the missing independent parameters. This would allow for example, to set design values for building weight and height, and to determine the unknown values for the corresponding radiuses and necessary sack dimensions which will produce a building that meets this pre requisites. | |
| This paper briefly explains a geometrical model of Superadobe domed structures.",1,https://api.osf.io/v2/files/5c8ac632075b640019a17731/,257,https://engrxiv.org/ptq47/,10.31224/osf.io/ptq47,,2019-03-14T21:27:43.512086,2019-03-15T14:23:46.987104 | |
| vhybk,"CONSTRUCTION OF A SUPERADOBE DOME","Superadobe Technology consists on filling long polypropylene sacks with a moist mixture of clay, sand, gravel and lime/cement; placing and compacting one on top of another forming concentric rings of decreasing radius and describing a double curvature monolith. | |
| From the 26th of August till the 6th of September of 2017, a group of 10 students at the “Domoterra” Institute of Earthbag construction, in the province of Teruel, autonomous community of Aragon, Spain, participated in the construction of what would become a Superadobe domed shelter of internal diameter 4m, roughly 3.5m high with the capacity to enclose 17.5m^2 of habitable surface, using approximately 250m of polypropylene sack and 20 m³ of earth. | |
| The structure advanced from an initial base cylinder of 0.5 m to the height of 2.1 m in 7 effective work days of 8 hours each day, and such an experience is taken into account together with existing literature, to describe the construction process of a Superadobe dome.",1,https://api.osf.io/v2/files/5c8a87548df5880016c3dbbd/,1562,https://engrxiv.org/vhybk/,10.31224/osf.io/vhybk,,2019-03-14T17:01:24.785285,2019-03-18T23:06:44.171462 | |
| u7aby,"Design and Evaluation of a Novel Low Acoustic Impedance-Based PZT Transducer for Detecting the Near-Surface Defects","Near-surface defects are one of the most common types of damage occurring in polymer composite materials. Conventional Non-Destructive Testing (NDT) techniques, especially ultrasonic testing, are not always suitable for detecting these types of defect, especially in thin plates. The proposed NDT method in this article employs Low Acoustic Impedance (LAI) characterization. The novelty of LAI technique lies in the transverse resonating of Lead-Zirconate-Titanate (PZT) transducer which shows significant lower effective acoustic impedance compared to thickness - extension mode. The LAI technique eliminates the need for the matching layers and reduces the manufacturing cost consequently. Briefly, the analytical model has been introduced and the fabrication procedure has been discussed in detail. The setup has been evaluated both numerically and experimentally to detect a debonding. The results proved the ability of LAI technique in the detection of defects and, moreover, the approximate geometry of the affected region as well.",1,https://api.osf.io/v2/files/5c8833be1d73810017c4c569/,517,https://engrxiv.org/u7aby/,10.31224/osf.io/u7aby,,2019-03-12T22:38:16.140199,2019-08-09T17:59:05.383014 | |
| uedzx,"Inter and Intra Patient ECG Heartbeat Classification For Arrhythmia Detection: A Sequence to Sequence Deep Learning Approach","Electrocardiogram (ECG) signal is a common and powerful tool to study heart function and diagnose several abnormal arrhythmias. While there have been remarkable improvements in cardiac arrhythmia classification methods, they still cannot offer acceptable performance in detecting different heart conditions, especially when dealing with imbalanced datasets. In this paper, we | |
| propose a solution to address this limitation of current classification approaches by developing an automatic heartbeat classification method using deep convolutional neural networks and sequence to sequence models. We evaluated the proposed method on the MIT-BIH arrhythmia database, considering the intra-patient and inter-patient paradigms, and the AAMI EC57 standard. The evaluation results for both paradigms show that our method achieves the best performance in the literature (a positive predictive value of 96.46% and sensitivity of 100% for the category S, and a positive predictive value of 98.68% and sensitivity of 97.40% for the category F for the intra-patient scheme; a positive predictive value of 92.57% and sensitivity of 88.94% for the category S, and a positive predictive value of 99.50% and sensitivity of 99.94% for the category V for the inter-patient scheme.). The source code is available at https://github.com/SajadMo/ECG-Heartbeat-Classification-seq2seq-model.",1,https://api.osf.io/v2/files/5c88254b1d73810017c4b4c9/,466,https://engrxiv.org/uedzx/,10.31224/osf.io/uedzx,,2019-03-12T21:33:36.665970,2019-03-14T17:10:15.958136 | |
| tj3c6,"Performance Evaluation of A Developed Acoustic Impedance Device In Tumor Screening","In this study, we test the performance of a PZT transducer using Low Acoustic Impedance (LAI) on detecting tumors embedded in agarose gels. Our hypothesis is that the structural and composition difference between the tumor and the gel would sufficiently result in variation in the measured acoustic impedance, and consequently can be used to detect the presence of the tumor located below the gel surface. The surface contour of the normalized impedance is mapped by scanning the device on the surface. The results are compared to the actual locations of the embedded tumors.",1,https://api.osf.io/v2/files/5c88128966b44d001d73ab3c/,167,https://engrxiv.org/tj3c6/,10.31224/osf.io/tj3c6,,2019-03-12T20:20:50.947719,2019-04-06T15:30:18.152384 | |
| mp7bq,"Damage Detection in Composites by LAI-PZT Transducer","Composite structures are known for being susceptible to manufacturing defects and | |
| in-service damage. Since damage in composites is not always visually apparent, Non- | |
| Destructive Techniques (NDT) such as ultrasonic imaging are often employed to detect and | |
| quantify damage [1]. Materials such as carbon-epoxy and fiberglass-epoxy plates are | |
| frequently used as structural elements in the both the civil and aerospace industry. Structure | |
| made of these materials display high acoustic impedances along the direction of the fibers but | |
| behave as Low Acoustic Impedance (LAI) materials in the transverse direction (i.e., through | |
| the composite’s thickness). It follows that LAI acoustic transducer are generally more | |
| appropriate to scan and detect damage/defects through the thickness in various types of | |
| anisotropic structures. When transducers are coupled in a direction orthogonal to the resonant | |
| mode they display significantly lower characteristic impedance than if coupled in the same | |
| direction. In some cases, this feature can eliminate the need for intermediate “matching” | |
| films and makes LAI transducer desirable for acoustic imaging applications. In this paper we | |
| introduce the use of low-cost, low effective impedance PZT transducer for damage detection | |
| in LAI structures. This manuscript also describes results from both numerical modeling and | |
| damage detection testing performed using a prototype transducer. In the future simple and | |
| economical transducers resonated in their transverse mode rather than the thickness mode | |
| could be used to detect damage such as matrix cracking and delamination of the composite | |
| structure.",1,https://api.osf.io/v2/files/5c87e6341d73810017c46570/,311,https://engrxiv.org/mp7bq/,10.31224/osf.io/mp7bq,,2019-03-12T17:17:14.691304,2019-03-12T20:00:38.355748 | |
| vbq6e,"Exploiting Synergy of Carbon Pricing and other Policy Instruments for Deep Decarbonization","We address both weaknesses and strengths of recent arguments against carbon pricing . In our opinion, however, carbon pricing is one essential component of a mix of policy instruments, as no single instrument will bring about the disruptive change needed to meet the Paris Agreement goals and achieve deep carbonization. We urge the research community to assess synergies and trade-offs between different policy instruments and to take into account the important role of their social and political acceptance.",1,https://api.osf.io/v2/files/5c87cb71245c0a0017d60b8a/,375,https://engrxiv.org/vbq6e/,10.31224/osf.io/vbq6e,10.1016/j.joule.2019.03.006,2019-03-12T15:24:01.873881,2019-04-02T19:39:41.429507 | |
| s3uzy,"Analytical and numerical study of entropy generation in small scale heat exchangers","In present work, the entropy generation minimization technique (EGM) is applied to study the performance of a microchannel heat sink combined with a new proposed parameter called irreversibility index and energy harvesting concept. Three different cases have been investigated using geometry of a microchanel heat sink selected from experimental work in the literature. The constraints considered in this study, are fixed channel height and maximum pressure drop. It has been observed that with fixed channel height constraint, while the aspect ratio changes from 1 to 10, the optimum operating condition fall in the range of Reynolds number equal to 2000 and aspect ratio of 2.25. Moreover, the extra constrain on maximum pressure drop imposes a limitation on applicable aspect ratio range. The maximum aspect ratio of the channel for stable flow field in this case cannot be higher than 5 imposed by criteria of laminar flow regime. The obtained optimum values are Reynolds number of 1850 and aspect ratio of 2. Using a combined new defined irreversibility index and Energy Harvesting Concept (EHC), it has been shown that the optimum design values for industrial applications are not necessary ones obtained from EGM method and may shift to a new operating point based on the method considered for energy harvesting.",1,https://api.osf.io/v2/files/5c8698291d73810017c2d8cd/,212,https://engrxiv.org/s3uzy/,10.31224/osf.io/s3uzy,,2019-03-11T17:22:00.694725,2019-07-02T14:29:37.017210 | |
| gu4pz,"Analytical Design and Estimation of Conventional and Electrical Aircraft Environmental Control Systems","Environmental control system holds vital importance as it is responsible for passenger’s ventilation and comfort. This paper presents an analytical design of environmental control systems and represents the estimated design in three-dimensional. Knowledge-based engineering application serves as the base for designing and methodology for the environmental control systems. Flexibility in the model enables the user to control the size and positioning of the system and also sub-systems associated with it. The number of passengers serves as the driving input and three-dimensional model gives the exact representation with respect to the volume occupied and dependencies on the number of passengers. It also provides a faster method to alter the system to user needs with respect to the number of air supply pipes, number of ducts and pipe length. Knowledge-based engineering gives the freedom to visualize various options in the conceptual design process.",1,https://api.osf.io/v2/files/5c869730245c0a0017d4c259/,547,https://engrxiv.org/gu4pz/,10.31224/osf.io/gu4pz,,2019-03-11T17:18:14.522130,2019-03-11T17:27:18.246427 | |
| h4wrv,"Cellular-resolution in vivo tomography in turbid tissue through digital aberration correction","Noninvasive tomographic imaging of cellular processes in vivo may provide valuable cytological and histological information for disease diagnosis. However, such strategies are usually hampered by optical aberrations caused by the imaging system and tissue turbidity. State-of-the-art aberration correction methods require that the light signal be phase stable over the full-field data acquisition period, which is difficult to maintain during dynamic cellular processes in vivo. Here we show that any optical aberrations in the path length difference (OPD) domain can be corrected without the phase stability requirement based on maximum intensity assumption. Specifically, we demonstrate a novel optical tomographic technique, termed amplitude division aperture synthesis optical coherence tomography (ADAS-OCT), which corrects aberrations induced by turbid tissues by physical aperture synthesis and simultaneously data acquisition from sub-apertures. Even with just two sub-apertures, ADAS-OCT enabled in vivo visualization of red blood cells in human labial mucosa. We further demonstrated that adding sub-apertures could significantly scale up the aberration correction capability. This technology has the potential to impact a number of clinical areas where noninvasive examinations are preferred, such as blood count and cancers detection.",1,https://api.osf.io/v2/files/5c84aa20245c0a0017d28485/,402,https://engrxiv.org/h4wrv/,10.31224/osf.io/h4wrv,,2019-03-10T06:21:28.005656,2019-03-11T14:50:47.329178 | |
| c7ujh,"Understanding and affecting school water behaviour using technological interventions","This paper studies and reports the water usage behaviour of a primary school in Stellenbosch in the period leading up to the 2018 drought. The aims of the study was to characterise water consumption patterns for a school, and to quantify the effects of the technology-driven interventions on behavioural change. Three interventions were implemented using smart meter data: posters, playing cards, and daily presentations. The school’s water usage pattern was found to be predictive and regular, except for daily losses, which were extrapolated from measured nightly flow. The water usage distribution was Gaussian with the mean being centred around break time. The interventions were able to reduce water consumption of the school by 44% when compared to the use of a school in the same town where the interventions were not implemented.",1,https://api.osf.io/v2/files/5c818dc054c9a20016f057ba/,321,https://engrxiv.org/c7ujh/,10.31224/osf.io/c7ujh,,2019-03-07T21:35:11.429509,2019-05-01T02:35:28.962521 | |
| m9teb,"ECGNET: Learning Where to Attend for Detection of Atrial Fibrillation (AF) with Deep Visual Attention","The complexity of the patterns associated with Atrial Fibrillation (AF) and the high level of noise affecting these patterns have significantly limited the current signal processing and shallow machine learning approaches to get accurate AF detection results. Deep neural networks have shown to be very powerful to learn the non-linear patterns in the data. While a deep learning approach attempts to learn complex pattern related to the presence of AF in the ECG, they can benefit from knowing which parts of the signal is more important to focus during learning. In this paper, we introduce a two-channel deep neural network to more accurately detect AF presented in the ECG signal. The first channel takes in a preprocessed ECG signal and automatically learns where to attend for detection of AF. The second channel simultaneously takes in the preprocessed ECG signal to consider all features of entire signals. The model shows via visualization that what parts of the given ECG signal are important to attend while trying to detect atrial fibrillation. In addition, this combination significantly improves the performance of the atrial fibrillation detection (achieved a sensitivity of 99.53%, specificity of 99.26% and accuracy of 99.40% on the MIT-BIH atrial fibrillation database with 5-s ECG segments.)",1,https://api.osf.io/v2/files/5c817e5440dc6f001cb2c23f/,234,https://engrxiv.org/m9teb/,10.31224/osf.io/m9teb,,2019-03-07T20:36:10.731080,2019-03-13T22:59:43.208740 | |
| mqwdb,"Impacts of Engineering: An Introductory Course in Engineering Featuring Social Justice","Impacts of Engineering is a three-credit required course for all incoming engineering freshmen and is also available as a general education elective to all university students. The course was developed to address the needs of new engineering students while setting the stage for how they might approach engineering work in later curriculum. Prior to the development of this course, engineering students at UW-Stout were exposed to the topics of ethics, social justice, and social responsibility solely through general education electives and through limited discussion in capstone courses. In addition, there is a selection of ``extra-curricular'' opportunities for student engagement, most notably a chapter of Engineers Without Borders USA, however these opportunities don’t carry curricular integration. The first effort at more directly integrating these topics into the engineering curriculum was through the development of a new course called ``Impacts of Engineering,'' which is described in the course documentation as shown in the following section. Broadly, this course supports the program educational objective of graduating students who are ``committed to high ethical standards, global perspectives, and principles of social responsibility and social justice.'' The course aims to supplement the technical content typically found in introductory engineering coursework with professional or life skills such as good communication, time management, and ability to function on a diverse team. Finally, the course objectives include several that are specifically directed at developing an understanding of engineering design from a global perspective.",1,https://api.osf.io/v2/files/5c7d852858e63b0019d5b265/,264,https://engrxiv.org/mqwdb/,10.31224/osf.io/mqwdb,,2019-03-04T20:07:46.569557,2019-03-29T21:00:23.811250 | |
| pgkqz,"Optimization of Hybrid Learning Approach for Power Electronics Course Using Virtual Laboratory to Prepare Teachers in Industry 4.0","Many challenges need to be addressed in facing the Industry 4.0 (I4.0), especially for teachers in schools or colleges. One of them is how to adapt a learning process with I4.0 where computers and technologies play an important role. A hybrid learning approach using a virtual laboratory could be the answer to this problem. Hybrid learning combines face-to-face learning, e-learning, virtual laboratory and practice in a laboratory. It could optimize the advantages of all methods and introduce educational technology to students. Furthermore, it will prepare the vocational teacher candidates in facing the I4.0. This paper | |
| focuses on developing, implementing and optimizing a power electronic course for vocational students with a hybrid learning approach using a virtual laboratory in Universitas Negeri Yogyakarta, Indonesia. The hybrid learning approach is validated by experts from electrical engineering education using an assessment method and analyzed by means statistically. The result shows that the hybrid learning approach by using virtual laboratory can be adopted for improving the analytical thinking skills | |
| in solving power electronics problems for students as a vocational teacher candidate.",1,https://api.osf.io/v2/files/5c7d6dc8ff4a89001b24b113/,259,https://engrxiv.org/pgkqz/,10.31224/osf.io/pgkqz,,2019-03-04T18:34:28.517726,2019-03-11T17:52:44.131302 | |
| fsa3c,"Ultrasound Segmentation of Cervical Muscle during head motion: a Dataset and a Benchmark using Deconvolutional Neural Networks","Objectives: To automate online segmentation of cervical muscles from transverse ultrasound (US) images of the human neck during functional head movement. To extend ground-truth labelling methodology beyond dependence upon MRI imaging of static head positions required for application to participants with involuntary movement disorders. Method: We collected sustained sequences (> 3 minutes) of US images of human posterior cervical neck muscles at 25 fps from 28 healthy adults, performing visually-guided pitch and yaw head motions. We sampled 1,100 frames (approx. 40 per participant) spanning the experimental range of head motion. We manually labelled all 1,100 US images and trained deconvolutional neural networks (DCNN) with a spatial SoftMax regression layer to classify every pixel in the full resolution (525x491) US images, as one of 14 classes (10 muscles, ligamentum nuchae, vertebra, skin, background). We investigated ‘MaxOut’ and Exponential Linear unit (ELU) transfer functions and compared with our previous benchmark (analytical shape modelling). Results: These DCNNs showed higher Jaccard Index (53.2%) and lower Hausdorff Distance (5.7 mm) than the previous benchmark (40.5%, 6.2 mm). SoftMax Confidence corresponded with correct classification. ‘MaxOut’ outperformed ELU marginally. Conclusion: The DCNN architecture accommodates challenging images and imperfect manual labels. The SoftMax layer gives user feedback of likely correct classification. The ‘MaxOut’ transfer function benefits from near-linear operation, compatibility with deconvolution operations and the dropout regulariser. Significance: This methodology for labelling ground-truth and training automated labelling networks is applicable for dynamic segmentation of moving muscles and for participants with involuntary movement disorders who cannot remain still.",1,https://api.osf.io/v2/files/5c75c9c362c82a0019dca6a4/,449,https://engrxiv.org/fsa3c/,10.31224/osf.io/fsa3c,,2019-02-26T23:24:40.612314,2019-03-26T20:09:15.796507 | |
| dafwr,"ADIBs: A Low-Cost Early Tsunami Warning System for Malaysia","Tsunami Warning System (TWS) consist detection and notification system that mostly operated by countries affected by Tsunami. For Malaysia, it is not cost effective to use cutting edge TWS. The reason is it free from big earthquakes where its location far from tectonic plate boundaries. Besides, it’s surrounded by neighbouring countries which act like natural wall to prevent natural disaster reach to Malaysia territory. Fatal Tsunami happened on 2004 has changed this fact and Malaysia is exposed to secondary effect of natural disaster happened at neighbouring countries. An earthquake with magnitude nine (9) occurred at Banda Aceh was generate Tsunami wave that propagate from Indonesia to Malaysia coastline killed 68 people. As an immediate action, Malaysian government introduce Malaysia Tsunami Early Warning System (SAATNM) which the technology behind the system is from imported equipment. Unfortunately, this sophisticated equipment is costly to maintain and it’s exposed to vandalise. Thus, ADIBs is acronyms for Aware Tsunami Detection Interconnected Built-In System is a TWS propose by authors to help Malaysian government agencies to develop a low cost and reliable TWS suitable for Malaysia usage. The authors also propose a novel method to calculate Tsunami risk which considers severity of Tsunami, occurrence of Tsunami and detection of Tsunami. Tsunami Failure Mode Effect Analysis (TFMEA) has successful informs Malaysia should focus on prevention works rather than using expensive TWS.",1,https://api.osf.io/v2/files/5c75794e62c82a0017e04ec1/,303,https://engrxiv.org/dafwr/,10.31224/osf.io/dafwr,,2019-02-26T17:44:20.776782,2019-02-26T18:50:55.412106 | |
| ghbcu,"Securing Data Encryption","This article provide analysis about information security using cryptography techniques. After the analyzing different techniques of encryption, we are proposing Advance Encryption Standard (AES). The AES has the better security compared others encryption algorithm and prevent data from Spoofing. It is very efficient in both hardware and software.",1,https://api.osf.io/v2/files/5c7295b48d5d98001b33fa70/,201,https://engrxiv.org/ghbcu/,10.31224/osf.io/ghbcu,,2019-02-24T13:03:52.817164,2019-02-24T20:31:47.393968 | |
| m74xz,"Evaluation of Comparative Damaging Effects of Multiple Truck Axles for Flexible Pavements","The objective of this research is to evaluate the comparative damaging effects of multiple truck axles including overloaded axles for asphalt pavements in the South Central region of the United States, by investigating the response of the pavement structure to various truck loading configurations.",1,https://api.osf.io/v2/files/5c71801082a3950019cbc615/,273,https://engrxiv.org/m74xz/,10.31224/osf.io/m74xz,,2019-02-23T17:23:41.167162,2019-02-24T20:31:00.232916 | |
| zfya9,"Particle Swarm Optimization in Virtual Power Plants with Cogeneration Systems","SXT Ariel proposal and contribution to the COST Action TD1207 “Mathematical Optimization in | |
| the Decision Support Systems for Efficient and Robust Energy Networks”, held at the same year 2016 affiliation at FCTUC, University of Coimbra, Portugal. With collaboration Professor Pedro S. Moura, ISR to share recent research and unveil new case studies concerning the use of optimization models to address the challenges arising in the evolution of energy networks to smart grids.",1,https://api.osf.io/v2/files/5c6fbf4f82a3950019ca9f7b/,283,https://engrxiv.org/zfya9/,10.31224/osf.io/zfya9,,2019-02-22T09:30:42.138623,2019-02-22T13:52:29.393519 | |
| 5zbpq,"A MICRO-STRUCTURAL MUSCLE FIBRE MODEL SHOWS TENSION-COMPRESSION ASYMMETRY MECHANISMS","Skeletal muscle tissue presents a highly asymmetrical behaviour when passively loaded in tension or compression, but no structural model addressing this has been reported. Passive skeletal muscle derives its structural response from titin filaments, collagen fibres | |
| in the connective tissue and incompressibility due to high fluid content. The objective of this paper is to develop a micro-structurally based mathematical model to predict the known tension-compression asymmetry. Such a model is a precursor to future constitutive formulations for finite element modelling.",1,https://api.osf.io/v2/files/5c6e7a0e82a3950018c93b02/,191,https://engrxiv.org/5zbpq/,10.31224/osf.io/5zbpq,10.1016/S0021-9290(12)70573-0,2019-02-21T10:23:25.628389,2019-02-21T15:20:07.656599 | |
| mejbx,"NON-INVASIVE ANALYSIS OF THE MECHANICAL PROPERTIES OF SKELETAL MUSCLE TISSUE IN-VIVO","Validation of constitutive models of living human skeletal muscle tissue requires non-invasive analysis methods. This abstract presents an advanced framework for the validation of such models. MRI based indentation experiments are proposed during which dynamic indentation force, 3D dynamic tissue deformation, tissue geometry and fibre architecture are recorded. Following inverse Finite Element Analysis (FEA) of the experimental boundary conditions the parameters of an appropriate constitutive law can be optimised. The framework presented allows for the first time for the non-invasive evaluation of detailed non-linear, anisotropic and viscoelastic material laws.",1,https://api.osf.io/v2/files/5c6e771782a3950017cb26b7/,270,https://engrxiv.org/mejbx/,10.31224/osf.io/mejbx,10.1016/S0021-9290(12)70489-X,2019-02-21T10:07:54.205380,2019-02-21T15:19:27.420462 | |
| f3hxk,"A Computationally Inexpensive Energy Model for Horizontal Electric Water Heaters With Scheduling","Electric water heaters (EWHs) remain one of the main contributors to energy consumption in countries where they are used. EWH models serve as a step towards achieving optimised control, and can also be used to inform users of expected savings due to changes, if the model is energy-based. Various models have been proposed, but none of them include more than half of the six key features that the model presented in this paper supports: horizontal orientation; schedule control; low computational complexity; validation of the model; multinodal stratification; and multinodal standing losses. The presented model is validated against six datasets: four comprising 900 hours with multiple water usage events; and two with only standing losses. The results show that the model estimates energy consumption over ten days including usage with an error of less than 2% and 5% for schedule control and thermostat control respectively. The simulation model is simple enough to execute ten days of simulation in less than 100 milliseconds on a standard desktop machine, 150 times faster than a prominent model from literature, making it also suitable for large scale simulations or for use on mobile devices.",1,https://api.osf.io/v2/files/5c6dd9ca8d5d98001a3289bb/,277,https://engrxiv.org/f3hxk/,10.31224/osf.io/f3hxk,10.1109/TSG.2016.2544882,2019-02-20T22:55:39.673420,2019-02-21T15:17:33.003435 | |
| 9x6df,"Estimating PV Power from Aggregate Power Measurements within the Distribution Grid","The increased integration of photovoltaic (PV) systems in distribution grids reduces visibility and situational awareness for utilities, because the PV systems’ power production is usually not monitored by them. To address this problem, a method called Contextually Supervised Source Separation (CSSS) has been recently adapted for real-time estimation of aggregate PV active power generation from aggregate net active and reactive power measurements at a point in a radially configured distribution grid (e.g., substation). In its original version, PV disaggregation is formulated as an optimization problem that fits linear regression models for the aggregate PV active power generation and true substation active power load. This paper extends the previous work by adding regularization terms in the objective function to capture additional contextual information such as smoothness, by adding new constraints, by introducing new regressors such as ambient temperature, and by investigating the use of time-varying regressors. Furthermore, we perform extensive parametric analysis to inform tuning of the objective function weighting factors in a way that maximizes performance and robustness. The proposed PV disaggregation method can be applied to networks with either a single PV system (e.g., MW scale) or many distributed ones (e.g., residential scale) connected downstream of the substation. Simulation studies with real field recorded data show that the enhancements of the proposed method reduce disaggregation error by 58% in winter and 35% in summer compared with previous CSSS-based work. When compared against a commonly used transposition model based approach, the reduction in disaggregation error is more pronounced (78% reduction in winter and 45% in summer). Additional simulations indicate that the proposed algorithm is applicable also for PV systems with time-varying power factors. Overall, our results show that – with appropriate modeling and tuning – it is possible to accurately estimate the aggregated PV active power generation of a distribution feeder with minimal or no additional sensor deployment.",1,https://api.osf.io/v2/files/5c6d402762c82a0017d799c6/,536,https://engrxiv.org/9x6df/,10.31224/osf.io/9x6df,,2019-02-20T12:03:49.316529,2019-04-09T18:20:59.068250 | |
| pyq29,"Indirect 3D bioprinting and characterization of alginate scaffolds for potential nerve tissue engineering applications","Low-concentration hydrogels have favorable properties for many cell functions in tissue engineering but are considerably limited from a scaffold fabrication point of view due to poor three-dimensional (3D) printability. Here, we developed an indirect-bioprinting process for alginate scaffolds and characterized the potential of these scaffolds for nerve tissue engineering applications. The indirect-bioprinting process involves (1) printing a sacrificial framework from gelatin, (2) impregnating the framework with low-concentration alginate, and (3) removing the gelatin framework by an incubation process, thus forming low-concentration alginate scaffolds. The scaffolds were characterized by compression testing, swelling, degradation, and morphological and biological assessment of incorporated or seeded Schwann cells. For comparison, varying concentrations of alginate scaffolds (from 0.5 to 3%) were fabricated and sterilized using either ultraviolet light or ethanol. Results indicated that scaffolds can be fabricated using the indirect-bioprinting process, wherein the scaffold properties are affected by the concentration of alginate and sterilization technique used. These factors provide effective means of regulating the properties of scaffolds fabricated using the indirect-bioprinting process. Cell-incorporated scaffolds demonstrated better cell viability than bulk gels. In addition, scaffolds showed better cell functionality when fabricated with a lower concentration of alginate compared to a higher concentration. The indirect-bioprinting process that we implemented could be extended to other types of low-concentration hydrogels to address the tradeoffs between printability and properties for favorable cell functions.",1,https://api.osf.io/v2/files/5c6ad9521650690018109d57/,301,https://engrxiv.org/pyq29/,10.31224/osf.io/pyq29,10.1016/j.jmbbm.2019.02.014,2019-02-18T16:21:42.635544,2019-02-18T16:26:23.822521 | |
| jwzrq,"Understanding Stability of Low-Inertia Systems","A large-scale integration of renewable generation,usually interfaced to the network through power electronics,has led to an overall decrease in power system inertia. This paper presents novel insights on the fundamental stability properties of such systems. For that purpose, a uniform set of Differential-Algebraic Equations (DAEs) describing a generic,low-inertia power system has been developed. A full-order, state-of-the-art control scheme of both synchronous and converter-based generators are included, with the latter differentiating between the grid-forming and grid-following mode of operation. Furthermore, the dynamics of transmission lines and loads are captured in the model. Using modal analysis techniques such as participation factors and parameter sensitivity, we determine the most vulnerable segments of the system and investigate the adverse effects of the underlying control interference. Finally, the appropriate directions for improving the system stability margin under different generation portfolios have been proposed.",1,https://api.osf.io/v2/files/5c6ace831431270019a0d7e5/,1049,https://engrxiv.org/jwzrq/,10.31224/osf.io/jwzrq,,2019-02-18T15:32:54.538441,2019-02-18T15:39:32.705891 | |
| 8ys2k,"Fluid-Structure Interaction Models of an Experimental Pulse Duplicator for Simulating Bioprosthetic Heart Valve Dynamics","Computer modeling and simulation (CM&S) is a powerful tool for assessing the performance of medical devices such as bioprosthetic heart valves (BHVs) and promises to accelerate device design and regulation. This study describes work to develop dynamic computer models of BHVs in the aortic test section of an experimental pulse duplicator platform that is used in academia, industry, and regulatory agencies to assess BHV performance. These computational models are based on a hyperelastic finite element (FE) extension of the immersed boundary (IB) method for fluid-structure interaction (FSI). We focus on porcine tissue and bovine pericardial BHVs, which are commonly used in surgical valve replacement. We compare our numerical simulations to experimental data from two similar pulse duplicators, including a commercial ViVitro system and a custom platform related to the ViVitro pulse duplicator. Excellent agreement is demonstrated between the computational and experimental results for bulk flow rates, pressures, valve open areas, and the timing of valve opening and closure in conditions commonly used in assessing BHV performance, and reasonable agreement is demonstrated for quantitative measures of leaflet kinematics under these same conditions. This work represents a step towards the experimental validation of this FSI modeling platform for evaluating BHVs.",1,https://api.osf.io/v2/files/5c674cb414312700179fc52d/,545,https://engrxiv.org/8ys2k/,10.31224/osf.io/8ys2k,,2019-02-16T00:33:16.117626,2019-07-10T01:27:07.064877 | |
| 8mbfu,"Parameter study of an inductively powered railgun","This article deals with the numerical simulation of an inductively powered railgun in order to determine the electrical parameters of the inductive storage of the pulsed power supply. A numerical model was set up and validated by experimental results. A parameter sweep was performed by varying the time constant of the coil, the initial current and the initially stored energy. The results show that the generated pulse shape, and thus the transfer efficiency and electromagnetic forces, strongly depend on the inductance of the storage coil. On the contrary, the dependency on the coil time constant, and thus on the coil volume for a given coil shape and conductor material, is small and can be neglected for high time constants.",1,https://api.osf.io/v2/files/5c6678651431270018a06662/,449,https://engrxiv.org/8mbfu/,10.31224/osf.io/8mbfu,,2019-02-15T08:42:32.006989,2019-02-15T15:14:11.181989 | |
| uy85x,"Eastward-moving convection-enhanced modons in shallow water in the equatorial tangent plane","We report a discovery of steady long-living slowly eastward moving large-scale coherent twin cyclones, the equatorial modons, in the shallow water model in the equatorial beta-plane, the archetype model of the ocean and atmosphere dynamics in tropics. We start by constructing analytical asymptotic modon solutions in the non-divergent velocity approximation and then show by simulations with a high-resolution numerical scheme that such configurations evolve into steady dipolar solutions of the full model. In the atmospheric context, the modons persist in the presence of moist convection, being accompanied and enhanced by specific patterns of water-vapour condensation.",1,https://api.osf.io/v2/files/5c65cb27f9de850018310403/,282,https://engrxiv.org/uy85x/,10.31224/osf.io/uy85x,10.1063/1.5080415,2019-02-14T20:16:20.919505,2019-02-14T20:32:06.409748 | |
| yahbu,"Bone Mineral Density (BMD)","Bone, the main constituent of the skeletal system is a hard tissue that results from the impregnation of a soft organic matrix (35%) (collagen fibers and non-collagenous proteins) by calcium and phosphorous, mainly in form of hydroxyapatite, (Ca10(PO4)6(OH)2), as well as carbonate, citrate, magnesium, fluoride, and strontium (65%) [1]. As calcium deposits, bone serves a critical function acting as a reservoir from which the mineral, vital to many physiologic processes, can readily be obtained. The most remarkable characteristic of bone is its ability to perceive changes in mechanical demands bestowed upon its components and realize the required structural transformation to adapt to new conditions. By way of this complex process of modeling and remodeling, bone cannot only grow stronger and harder but can also modify its form.",1,https://api.osf.io/v2/files/5c5fcb12832ca60017b0ae71/,182,https://engrxiv.org/yahbu/,10.31224/osf.io/yahbu,10.19080/CTBEB.2017.02.555576,2019-02-10T07:00:00.581028,2019-02-11T15:49:59.901206 | |
| zkvn9,"Fuel Cycle Performance of Fast Spectrum Molten Salt Reactor Designs","4 fast-spectrum molten salt conceptual designs have been selected for fuel cycle performance analysis. 3D full core and 2D unit cell models have been developed to justify the possibility to use a simplified model for computational-heavy depletion simulation with truly continuous online reprocessing. Finally, 60-years depletion simulation for Molten Salt Fast Reactor (MSFR) shown lifetime breeding ratio 1.0072 and doubling time 139 years in Th/U fuel cycle.",1,https://api.osf.io/v2/files/5c5f2aaa832ca6001aab7952/,278,https://engrxiv.org/zkvn9/,10.31224/osf.io/zkvn9,10.13140/RG.2.2.27131.00804,2019-02-09T19:41:07.254535,2019-02-14T16:56:16.462414 | |
| ajvkq,"DESIGN OF INTEGRATED ENERGY HARVESTING SYSTEM ON WINDOW BUILDING USING SOLAR PV","The current building is expected to provide physical comfort, such as room comfort, temperature, sound and lighting. Some equipment is needed that requires electrical energy to provide physical comfort. Like a room cooling device to provide thermal comfort, a room lamp to provide lighting comfort. The ITERA building built by the City Government of Bandar Lampung has high solar energy potential. While the electricity source still uses diesel fuel. The potential for solar energy radiation is used to become electrical energy by using glass windows as the foundation for installing solar energy harvesting systems using solar PV.",1,https://api.osf.io/v2/files/5c5d874876653c001826b8e7/,243,https://engrxiv.org/ajvkq/,10.31224/osf.io/ajvkq,,2019-02-08T13:45:12.262050,2019-02-08T17:17:23.988760 | |
| jxnrm,"High-dimensional Variance based Logic for Reliable Communication at Near-zero Energy-per-bit","In variance-based logic (VBL), information is encoded by the change in the variance of a signal as opposed to the conventional mean-based logic (MBL) where the information is encoded by the change in the mean of the signal. In this paper, we compare the fundamental limits on the minimum energy per bit that can be achieved by VBL and MBL representations in high-dimensional signal space. We show that while for MBL representations, the trade-off between the energy-per-bit and the bit-error-rate (BER) is fundamentally constrained by the classical Shannon-limit, using VBL representations it is theoretically possible to achieve arbitrarily small BER while dissipating near zero energy-per-bit. This surprising result has been experimentally verified for Additive-white-Gaussian-Noise (AWGN) channels using Monte-Carlo simulations. We believe that high-dimensional VBL based encoding could provide a new approach for designing ultra-energy-efficient communication and sensing systems.",1,https://api.osf.io/v2/files/5c5cb4c3e16f5500178eb963/,297,https://engrxiv.org/jxnrm/,10.31224/osf.io/jxnrm,,2019-02-07T23:04:30.319617,2019-02-08T17:42:06.592808 | |
| cfxdr,"Novel Hyperelastic Models for Large Volumetric Deformations","Materials such as elastomeric foams, lattices, and cellular solids are capable of undergoing large elastic volume changes. Although many hyperelastic constitutive formulations have been proposed for deviatoric (shape changing) behaviour, few variations exist for large deformation volumetric behaviour. The first section of this paper presents a critical analysis of current volumetric hyperelastic models and highlights their limitations for large volumetric strains. In the second section of the paper we propose three novel volumetric strain energy density functions, which: 1) are valid for large volumetric deformations, 2) offer separate control of the volumetric strain stiffening behaviour during shrinkage (volume reduction) and expansion (volume increase), and 3) provide precise control of non-monotonic volumetric strain stiffening. To illustrate the ability of the novel formulations to capture complex volumetric material behaviour they are fitted and compared to a range of published experimental data.",1,https://api.osf.io/v2/files/5c59edb5e16f5500188a0311/,399,https://engrxiv.org/cfxdr/,10.31224/osf.io/cfxdr,,2019-02-05T20:16:46.295547,2019-05-30T11:05:06.398706 | |
| r53pm,"3D ultrasound imaging of residual limbs with camera-based motion compensation","Ultrasound is a cost-effective, readily available, and non-ionizing modality for musculoskeletal imaging. Though some research groups have pursued methods that involve submerging the transducer and imaged body segment into a water bath, many limitations remain in regards to acquiring an unloaded volumetric image of an entire human limb in a fast, safe and adequately accurate manner. A 3D dataset of a limb is useful in several rehabilitative applications including biomechanical modeling of soft tissue, prosthetic socket design, monitoring muscle condition and disease progression, bone health, and orthopedic surgery. This paper builds on previous work from our group and presents the design, prototyping, and preliminary testing of a novel multi- modal imaging system for rapidly acquiring volumetric ultrasound imagery of human limbs, with a particular focus on residual limbs for improved prosthesis design. Our system employs a mecha- nized water tank setup to scan a limb with a clinical ultrasound transducer, and 3D optical imagery to track motion during a scan. The iterative closest point algorithm is utilized to compensate for motion and stitch the images into a final dataset. The results show preliminary 2D and 3D imaging of both a tissue-mimicking phantom and residual limbs. A volumetric error compares the ultrasound image data obtained to a previous MRI method. The results indicate potential for future clinical implementation. Con- cepts presented in this work could reasonably transfer to other imaging applications such as acoustic tomography, where motion artifact may distort image reconstruction.",1,https://api.osf.io/v2/files/5c57ae9c76653c001a235bef/,441,https://engrxiv.org/r53pm/,10.31224/osf.io/r53pm,10.1109/TNSRE.2019.2894159,2019-02-04T03:23:32.104873,2019-02-04T13:26:26.363180 | |
| u64nc,"Blo-Wiper: From Conceptual Design to Computer Simulation Analysis for New National Car Development Project (A Case Study for Malaysia Small Medium Enterprise-SME)","Blo-Wiper is a project proposed by Techno Brozek Enterprise to Malaysian government in 3rd National Car Project (NNCP). According to a feasibility study conducted by them, conventional windshield wiper is less effective during heavy rains especially for countries located at equatorial. They came out with Blo-Wiper idea which is a novel system that combined two mechanisms; wiping and blowing. Their first white paper is covered on feasibility study and concept development. Then, they continue their Research and Development (R&D) from conceptual design to computer simulation analysis by using Proof of Concept (PoC) process. Interaction of rain droplets with blowing air is simulated by using Computational Fluid Dynamics(CFD). CFD result for windshield wiper with blowing air proven that rain droplets are shattered and repelled towards left and right of boundary layer. Meanwhile, without air blowing, the rains droplets falling down on floor boundary layer. Rain Droplets Removing Width (RDRW) for a system with wiping and blowing is 76mm while conventional system is zero. That means, Blo-Wiper mechanisms; wiping and blowing is better than conventional mechanism; wiping only. The objective of this white paper is to publish R&D progress which is development from conceptual phase to numerical simulation phase.",1,https://api.osf.io/v2/files/5c5574b676653c001b22afa8/,230,https://engrxiv.org/u64nc/,10.31224/osf.io/u64nc,,2019-02-02T10:53:00.980904,2019-02-02T16:10:00.945896 | |
| 2aurb,"Cluster-based characterisation of Australian apartment electricity demand and its implications for low-carbon cities","Understanding of residential electricity demand has application in efficient building design, network planning and broader policy and regulation, as well as in planning the deployment of energy efficiency technologies and distributed energy resources with potential emissions reduction benefits as well societal and household cost savings. Very few studies have explored the specific demand characteristics of apartments, which house a growing proportion of the global urban population. | |
| We present a study of apartment electricity loads, using a dataset containing a year of half-hourly electricity data for 6000 Australian households, to examine the relationship between dwelling type, demographic characteristics and load profile. The focus on apartments, combined with the size of the data set, and the representative seasonal load profiles obtained through clustering full annual profiles, is unique in the literature. We find that median per-occupant household electricity use is 21% lower for apartments than for houses and that, on average, apartments have lower load factor and higher daily load variability, and show greater diversity in their daily peak times, resulting in a lower coincidence factor for aggregations of apartment loads. Using cluster analysis and classification, we also show the impact of dwelling type on the shape of household electricity load profiles.",1,https://api.osf.io/v2/files/5c52a24704d9bb001a7fcb2f/,425,https://engrxiv.org/2aurb/,10.31224/osf.io/2aurb,10.1016/j.energy.2019.04.222,2019-01-31T07:27:56.850841,2019-05-21T12:36:28.110387 | |
| p6uc8,"Experimental detection of debonding of piezoelectric sensors with the segmented electrode","The piezoelectric transducers (PZT) are bonded to smart structures by means of an intermediate adhesive layer, with the main objectives of applying methodologies of structural health monitoring, nondestructive evaluation, nondestructive inspection and structural control to the structures. However, the application of these methodologies depends on the health of the adhesive joint that couples mechanically the PZT with the structure. This research shows an experimental technique based on the segmentation of electrodes of a PZT patch in sheet form. One electrode is segmented in three equal parts (end left, middle and end right) to obtain three electrical signatures of a PZT. The electrical signatures (voltage) of the end electrodes are related to the middle electrode voltage. Three experiments were carried out in this study: two static cases and one dynamic case. For the static case, the left end (first case) and the right end (first case) were debonded. In the dynamic case, only one side was debonded. The results show that the voltage relations present linear behavior and the changing in the slope of the voltage ratio allows identifying which electrode is debonded. This technique showed to be effective in the three studied cases of debonding and it could be used to identify debonding in real time",1,https://api.osf.io/v2/files/5c501db3568329001c7f9987/,187,https://engrxiv.org/p6uc8/,10.31224/osf.io/p6uc8,10.13140/RG.2.1.1610.2160,2019-01-29T09:39:45.060569,2019-01-29T15:55:41.534603 | |
| b6k4f,"Comparing fast neutron transport calculations using code package KATRIN-2.0 for various options of VVER-440 core setup","Calculation of radiation exposure for VVER reactor vessel is a key task for the following determination of their burn-up life. This problem is especially topical for VVER-440 reactors of the first generation which now require substantiation report of safe operation over-designed service life. The estimation of radiation exposure of the reactor vessel involves the calculation of fast neutron fluence (E≥0.5 MeV) on welded joints and basis metal of the reactor vessel. The result of neutron fluence calculation and the associated estimation error are affected by the precision of fission neutron source definition in the reactor core. This study examines two approaches to defining fission neutron source in the fuel assembly: specifically, assembly-wise distribution, as well as rod-wise distribution approaches. | |
| The main objective of this work is to characterize the difference in calculation results of neutron fluence (E≥0.5 | |
| MeV) on the VVER-440 reactor vessel at rod-wise and assembly-wise definition of the fission neutron source in | |
| peripheral fuel assemblies, and to estimate the accuracy of fluence calculation for each source definition method, by | |
| comparing them with some experimental data. The present study examines the results of two different experiments carried out on the block of No.1 of Kola Nuclear Power Plant (V-230): each involving activity measurement for templates cut out on the internal reactor vessel surface and activity measurement of neutron-activation detectors of Niobium on the external reactor vessel surface.",1,https://api.osf.io/v2/files/5c4f1a51568329001b821212/,274,https://engrxiv.org/b6k4f/,10.31224/osf.io/b6k4f,,2019-01-28T15:07:57.141932,2019-02-09T19:53:01.903714 | |
| 27mda,"Nitrogen Oxide Evolution in Oxy-Coal Combustion","This paper investigates emissions of NOx from pulverized coal burning in O2/CO2 environments. | |
| Such environments are pertinent to oxy-coal combustion, a promising “clean-coal” technology. The replacement of the inert nitrogen gas in air with carbon dioxide, which has different physical properties, alters the combustion conditions in the furnace. Hence, the purpose of this | |
| work is to theoretically examine the effects of (a) the oxygen concentration in the O2/CO2 gases, | |
| and (b) the resulting combustion temperatures, on the evolution of NOx. To achieve these goals a | |
| previously published kinetic model was used, which assumes that fuel-bound nitrogen is released | |
| along with the tars during coal devolatilization and converts mostly to hydrogen cyanide. A sizable fraction of hydrogen cyanide is then converted to NO. Flame simulations were performed using Cantera to investigate the relative impacts of temperature and oxygen mole fraction, and to understand the causes of the observed trends.",1,https://api.osf.io/v2/files/5c4e4e160d1c9e00194c1f00/,348,https://engrxiv.org/27mda/,10.31224/osf.io/27mda,,2019-01-28T00:40:30.276192,2019-01-28T19:33:42.544951 | |
| 5bxed,"Formation of Acid Gases from Co-firing of Coal with Raw and Torrefied Biomasses","This work examined the emission for SO2, NOx, and CO2 gases from the combustion of pulverized coals, raw and torrefied biomasses, and 50-50 wt% blends thereof. The fuel samples chosen for this work are a high-sulfur bituminous coal (Illinois #6), a low-sulfur sub-bituminous coal (Powder River Basin), a herbaceous biomass (corn straw) and a crop-related biomass (rice husk). All fuel samples were burned in a laboratory-scale electrically-heated drop-tube furnace (DTF), operated at 1400 K, and combustion emissions were measured in the furnace effluent. Coal and biomass particles were in the ranges of 75-90 μm and 90-150 μm, respectively. Results showed beneficial synergisms for almost all blend samples that can reduce the SO2 and NOx emissions to values below those predicted by linear interpolation of the SO2 and NOx emissions of the involved neat fuels.",1,https://api.osf.io/v2/files/5c4e4cd2bf723100187a4edd/,294,https://engrxiv.org/5bxed/,10.31224/osf.io/5bxed,,2019-01-28T00:32:45.280483,2019-01-28T19:32:39.677179 | |
| 42hg7,"Torrefied Biomass Size for Combustion in Existing Boilers","A fundamental investigation was conducted on the combustion characteristics in air of different torrefied biomass particles size ranges. The targeted biomass types were waste crop, herbaceous and woody. The experimental setup that was used in this investigation consisted of a drop-tube furnace, operated at a wall temperature of 1400 K, and a three-color pyrometer, interfaced with the furnace. Entire luminous particle combustion profiles of individual particles were recorded. Results are compared with relevant past data on the combustion characteristics of single coal particles of different ranks, burned in the same furnace under identical operating conditions. The goal of this work is to identify the appropriate size of torrefied biomass particles whose combustion durations match those of 75-90 μm pulverized coal particles, which is a size typically used in pulverized fuel boilers. Such data will be useful in deciding the fuel sizing for co-firing coal with biomass.",1,https://api.osf.io/v2/files/5c4e4463bf723100167cbd5c/,332,https://engrxiv.org/42hg7/,10.31224/osf.io/42hg7,,2019-01-28T00:04:09.380373,2019-01-28T19:31:54.954584 | |
| 5atbz,"Non-Invasive Estimation of Domestic Hot Water Usage with Temperature and Vibration Sensors","Electric water heaters are responsible for a large portion of electricity consumption and water usage in the domestic sector. Smart water heaters alleviate the strain on the electricity supply grid and reduce water consumption through behavioural change, but the installation of in-line flow meters is inconvenient and expensive. A non-invasive water flow meter is proposed as an alternative. Non-invasive flow measurement is more common for high flow rates in the industrial sector than for domestic applications. Various non-invasive water measurement methods are investigated in the context of domestic hot water, and a combination of thermal- and vibration-sensing is proposed. The proposed solution uses inexpensive, easily installable, non-invasive sensors and a novel algorithm to provide the same flow measurement accuracy as existing in-line meters. The algorithm detects the beginning and end of water consumption events with an accuracy of 95.6%. Quantitative flow rate estimation was possible for flow rates greater than 5 L min⁻¹ with an accuracy of 89%, while volumetric usage estimation had an accuracy of more than 93%. The algorithm limitations were applied to field data, revealing that water consumption could be detected with an error of less than 12% within the limitations of the proposed algorithm. The paper presents a successful proof of concept for a non-invasive alternative to domestic hot water flow rate measurement.",1,https://api.osf.io/v2/files/5c4c39c0bf723100167abe31/,212,https://engrxiv.org/5atbz/,10.31224/osf.io/5atbz,10.1016/j.flowmeasinst.2018.07.003,2019-01-26T10:48:37.711830,2019-01-26T15:53:11.915096 | |
| aq6vw,"Electric Water Heater Energy Consumption Determination Using Outlet Temperature and Volumetric Estimation","This paper presents the use of outlet temperature and water meter data as inputs to a physical model of a domestic electric water heater (EWH) for estimating the energy consumption for various control settings. Four sets of actual household data, consisting of at least 7 consecutive days each, is used to determine the accuracy of the energy consumption estimates in comparison to measured energy consumption. Both the outlet temperature and water meter data inputs used were able to estimate the total energy input with an error of less than 10 percent for 3 of the 4 datasets considered. Additionally, both methods are also implemented as a smartphone application that can be used to obtain input from users, as well as provide instantaneous feedback on the impact of control changes.",1,https://api.osf.io/v2/files/5c4c36f1568329001c7dd720/,316,https://engrxiv.org/aq6vw/,10.31224/osf.io/aq6vw,10.1109/SSCI.2015.102,2019-01-26T10:35:55.776529,2019-05-05T11:10:18.656131 | |
| gw38s,"The photocatalytic Enhancement of TiO2 Nanotubes by Simultaneously Doping Ag Nanoparticles During Anodization Process: Photocatalytic Degradation of 2,4-Dicholorophenol","Ag-Doped TiO2 nanotubes (TNTs) were fabricated with facile two-step anodization process. In addition, the catalytic activity of Ag-Doped TiO2 nanotubes was examined in photocatalytic degradation of 2,4-dicholorophenol. Characterizing of Ag-Doped TiO2 nanotubes were evaluated by FESEM, TEM, XRD, DRS and Spectrophotometry analyses. Results show that doping Ag nanoparticles uniformly distributed over the TNTs without any distraction in a tubular structure. Anatase crystalline phase was obtained by annealing the Ag-Doped TNTs at 550 °C. DRS results showed the addition of Ag nanoparticles had a sufficient effect of band gap which it decreased the band gap from 2.9 to 2.7. Pure TiO2 nanotubes showed 74% removal of 2,4-dicholorophenol. photocatalytic degradation study indicated that Ag-dopant has an efficient impact on photocatalytic activity of TNTs witch Ag-Doped TNTs could degrade 91% of 2,4-dicholorophenol under UV irradiation.",1,https://api.osf.io/v2/files/5c4b887b568329001d7ddf0f/,272,https://engrxiv.org/gw38s/,10.31224/osf.io/gw38s,,2019-01-26T07:22:53.711809,2019-01-26T15:48:57.288771 | |
| jkexd,"Optimised 3D-Printed Metallic Node-Connections for Reticulated Structures","Abstract. Structural Topology Optimisation (STO) is a prevalent optimisation technique used nowadays to reach highly complex and efficient designs (weight-to-stiffness ratio) unable to achieve otherwise. Additive Manufacturing (AM) is a developing manufacturing process which overcomes many of the manufacturing limitations and realises highly optimised products through a layer-based fabrication process. Recent research on reticulated structures proposed using STO and 3D printing to design and fabricate alternative bespoke complex connection designs which have shown its significance through obtaining substantial weight reductions for the same structural capacity. This paper builds on previous research through optimising a single-layer S355 traditional node-connection under four loading cases, producing a state-of-the-art optimised connection design capable of withstanding the four loading cases considered and comparing the results to the traditional ones. In all loading cases, optimised shapes with 46.90% weight reduction were obtained with varying stress levels. A selection of the highly bespoke designs were 3D printed as a proof of concept for the applicability of AM.",1,https://api.osf.io/v2/files/5c5aa3b9e16f5500188ad22b/,384,https://engrxiv.org/jkexd/,10.31224/osf.io/jkexd,,2019-01-24T21:49:06.487647,2019-01-24T21:49:06.557400 | |
| 38gaq,"Online Reprocessing Simulation for Thorium-Fueled Molten Salt Breeder Reactor","The current paper presents a single-cell model developed using the continuous-energy Serpent 2 Monte Carlo reactor physics software. It was employed to establish a Serpent- based method for finding the equilibrium core composition and core depletion of the Molten Salt Breeder Reactor (MSBR).",1,https://api.osf.io/v2/files/5c473bbb154ce50018dfb88a/,394,https://engrxiv.org/38gaq/,10.31224/osf.io/38gaq,,2019-01-22T15:52:51.056373,2019-01-22T18:31:08.245801 | |
| nwrj7,"Removing SYN flooding in TCP/IP Network","Transmission Control Protocol (TCP), the most popular transport layer communication protocol for the Internet. It was originally designed for wired networks, where Denial of Service (DoS) attacks are very common. This article analyzes the TCP SYN flood (a.k.a. SYN flood) Issue in TCP, that is a type of Distributed Denial of Service (DoS) attack that exploits part of the normal TCP three-way handshake to consume resources on the targeted server and render it unresponsive. At the end it proposes solution for TCP SYN flood.",1,https://api.osf.io/v2/files/5c46ba5b154ce50016e15fb8/,482,https://engrxiv.org/nwrj7/,10.31224/osf.io/nwrj7,,2019-01-22T06:41:05.801333,2019-01-22T13:33:34.308412 | |
| tcx45,"Partial Input-output Analysis of Tourism Market: Identifying Potential Embodied Energy Impacts","World Sustainable Energy Days 2018 Digital Proceeding Archive",1,https://api.osf.io/v2/files/5c45f8872e57200019fc0f36/,331,https://engrxiv.org/tcx45/,10.31224/osf.io/tcx45,,2019-01-21T16:55:06.366753,2019-01-22T02:27:20.054406 | |
| rc8pq,"Use of smart grid technology to compare regions and days of the week in household water heating","Water heating is a leading cause of household energy consumption and, given its capacitive nature, has been the focus of research on demand side management and grid peak load management. Despite all the existing literature on energy for water heating, very little is known about an inextricably linked key determinant of it - demand for hot water and consumption patterns thereof. Moreover, even though water heating energy demand profiles have been investigated in the past, little is known about the different energy profiles for the days of the week, and regional variance of such profiles. This paper measures and reports actual hot water demand acquired through a novel smart metering solution. The different profiles for the days of the week are evaluated, in addition to weekdays and weekend days. Finally, differences between units in peri-rural Mkhondo and the urban Western Cape are compared in terms of water demand, energy demand, and efficiency (energy in vs. energy out). The results show a striking similarity to previous work, with the exception that scheduling has led to energy demand leading water consumption. The results also show that daily routines vary significantly, and also between regions. Surprisingly, the efficiencies and consumption patterns between the regions are also stark, with the urban Western Cape using 20 % more water on an average day, and with 70.2 % efficiency vs. 45.8 % in Mkhondo.",1,https://api.osf.io/v2/files/5c45886f154ce50016e050c3/,308,https://engrxiv.org/rc8pq/,10.31224/osf.io/rc8pq,10.23919/DUE.2017.7931855,2019-01-21T09:00:12.834629,2019-01-22T02:22:31.957687 | |
| 9qkct,"Highway Tracking and Mapping Using Mobile GPS Techniques","Mobile GPS instrument was used in this study for highway tracking and mapping within Duhok city. As many as 30 trips were made along the city street for this purpose. The data is downloaded and processed in a computer. Each track is converted into a vector line map. The many tracks along a single street consist of a bunch of adjacent lines. A group mean was derived and plotted. A network of the tracks mean representing the centerlines of the street within the selected test site was presented. The positional horizontal accuracy of these lines was checked with reference to a base map produced by a total station instrument. The standard deviation of the centerline deviation was ± 0.92m. The derived tracks mean was successfully superimposed over a raster satellite Google Earth image.",1,https://api.osf.io/v2/files/5c44a781377632001c2ac7e2/,364,https://engrxiv.org/9qkct/,10.31224/osf.io/9qkct,,2019-01-20T17:05:16.053173,2019-01-22T02:21:20.490338 | |
| u5f6t,null,"this is null null null",1,https://api.osf.io/v2/files/5c3fb8c9e8da0e001858d7fa/,288,https://engrxiv.org/u5f6t/,10.31224/osf.io/u5f6t,,2019-01-16T23:07:57.088208,2019-06-15T17:39:01.167351 | |
| ny9df,"Comfort, peak load and energy: Centralised control of water heaters for demand-driven prioritisation","Recent advances in smart grid technology enable new approaches to address the problem of load control for domestic water heating. | |
| Since water heaters store energy, they are well-suited to load management. | |
| However, existing approaches have focused on the electrical supply side, ignoring the obvious link between the user and the grid: individual hot water consumption patterns. | |
| This paper proposes a load spreading approach in which water heaters compete for access to the heating medium. | |
| The proposed smart grid solution takes grid load limits, real-time temperature measurements, water usage patterns, individual user comfort, and heater meta-data into consideration. | |
| The scheduler only turns on the heaters with the highest level of need, but limits the number of on heaters to ensure that the grid load stays below a set limit for a set time. | |
| The method is evaluated by simulation against various heater set temperature levels, and for various load limits, and compared with ripple control and actual consumption measured in a field trial of 34 water heaters. | |
| The proposed algorithm reduces the load from 62kW to 20, 30, 40, and 50kW (vs. 106kW for full ripple control). The resulting number of unwanted cold events is fewer than for ripple control, and only slightly more than no control, while reducing the total energy by 14% from a user-optimised natural experiment.",1,https://api.osf.io/v2/files/5c3e41c58047080019fc7308/,340,https://engrxiv.org/ny9df/,10.31224/osf.io/ny9df,10.1016/j.esd.2018.03.006,2019-01-15T20:30:00.778940,2019-01-15T20:35:24.241839 | |
| k8ah4,"Computations of heave added mass and damping coefficients of some axisymmetric bodies using WAMIT","The heave added mass and damping coefficients of some axisymmetric rigid bodies computed using WAMIT are compared with those computed using semi-analytical methods.",1,https://api.osf.io/v2/files/5c38b71e7cf3f5001bb4aa07/,330,https://engrxiv.org/k8ah4/,10.31224/osf.io/k8ah4,,2019-01-11T15:40:23.647289,2019-01-11T15:51:10.484699 | |
| rejcn,"A framework for measuring the time-varying shape and full-field deformation of residual limbs using 3D digital image correlation","Effective prosthetic socket design following lower-limb amputation depends upon the accurate characterization of the shape of the residual limb as well as its volume and shape fluctuations. Objective: This study proposes a novel framework for the measurement and analysis of residual limb shape and deformation, using a high-resolution and low-cost system. Methods: A multi-camera system was designed to capture sets of simultaneous images of the entire residuum surface. The images were analyzed using a specially developed open-source three-dimensional digital image correlation (3D-DIC) toolbox, to obtain the accurate time-varying shapes as well as the full-field deformation and strain maps on the residuum skin surface. Measurements on a transtibial amputee residuum were obtained during knee flexions, muscle contractions, and swelling upon socket removal. Results: It was demonstrated that 3D-DIC can be employed to quantify with high resolution the time-varying residuum shapes, deformations, and strains. Additionally, the enclosed volumes and cross-sectional areas were computed and analyzed. Conclusion: This novel low-cost framework provides a promising solution for the in-vivo evaluation of residuum shapes and strains, as well as the potential for characterizing the mechanical properties of the underlying soft-tissues. Significance: These data may be used to inform data-driven computational algorithms for the design of prosthetic sockets, as well as of other wearable technologies mechanically interfacing with the skin.",1,https://api.osf.io/v2/files/5c37ce127cf3f50018b74aaf/,584,https://engrxiv.org/rejcn/,10.31224/osf.io/rejcn,10.1109/TBME.2019.2895283,2019-01-10T23:08:58.256426,2019-09-24T19:27:16.530979 | |
| t6zdv,"A new perspective on global renewable energy systems: why trade in energy carriers matters","Recent global modelling studies suggest a decline of long-distance trade in energy carriers in future global renewable energy systems, compared to today’s fossil fuel energy system. In contrast, we identified four crucial drivers that enable trade of renewable energy carriers. These drivers could make trade remain at current levels or even increase during the transition to an energy system with very high shares of renewables. | |
| First, new land-efficient technologies for renewable fuel production become increasingly available and technically allow for long-distance trade in renewables. Second, regional differences in social acceptance and land availability for energy infrastructure support the development of renewable fuel import and export streams. Third, the economics of renewable energy systems, i.e. the different production conditions globally and the high costs of fully renewable regional electricity systems, will create opportunities for spatial arbitrage. Fourth, the reduction of stranded investments in the fossil fuel sector is possible by switching from fossil fuel to renewable fuel trade in exporting regions. | |
| The impact of these drivers on trade in energy carriers is currently under-investigated by the global energy research community. Therefore, we call for a major research effort in this field, in particular as trade can redistribute profits and losses of climate change mitigation and may hence support finding new partners in climate change mitigation negotiations.",1,https://api.osf.io/v2/files/5c35e9067cf3f50018b5a11a/,538,https://engrxiv.org/t6zdv/,10.31224/osf.io/t6zdv,,2019-01-09T12:35:55.253573,2019-01-11T17:43:44.450489 | |
| eybz7,"Upper Bound Method for Yield Design of Reinforced Concrete Slabs Using Conic Programming and an Adaptive Remeshing Strategy","This study presents a numerical procedure for the analysis of reinforced concrete slabs (RCS) that obey Nielsen's yield criterion (slabs orthogonally reinforced). An upper bound formulation combined with finite elements was established to solve the kinematic theorem as a conic optimization problem with the aim to determine the maximum bearing capacity of RCS. Discrete Kirchhoff finite elements were implemented and adapted to establish a limit state problem for the yield design. By using Nielsen´s criterion, a kinematic criterion was established applying the flow rule of plasticity. The kinematic criterion was included in the upper bound formulation with the aim to constraint the curvatures of the slab. The upper bound formulation was organized in the standard form of a second order cone programming (SOCP) problem since the kinematic criterion was formulated in conic form. Numerical examples were proposed to test the accuracy of the method including the adaptive remeshing strategy.",1,https://api.osf.io/v2/files/5c3507147cf3f5001ab2d750/,278,https://engrxiv.org/eybz7/,10.31224/osf.io/eybz7,,2019-01-08T20:29:22.295672,2019-01-08T21:25:56.634081 | |
| qgkew,"Determination of Detachment Frequencies of Ripe Coffee Fruits (Coffea Arabica Var. Colombia) by Means of a Numerical and Experimental Approach","In this study, it is proposed an experimental and numerical approach to identify a bandwidth of harmonic frequencies where ripe fruits of Coffea arabica L. var. Colombia can be selectively stimulated. For this purpose, a geometric model was designed computationally to represent the topology of the coffee fruit-peduncle system in all ripening stages. Using analytical models and pseudo-experimental data, the mechanical properties were estimated to carry out a finite element analysis of the system. It was verified with a detachment model that fruits can be detached when a specific harmonic force (mechanical vibrations) is applied on the fruits in determined frequencies which correspond to the second vibration mode of the fruits. Results indicate that dynamic excitations between 130 to 150 Hz could detach only ripe fruits since fruits that were in other ripening stages were not stimulated until detachment in that bandwidth.",1,https://api.osf.io/v2/files/5c35041ee8da0e001a53686d/,297,https://engrxiv.org/qgkew/,10.31224/osf.io/qgkew,,2019-01-08T20:18:12.436845,2019-01-11T17:47:19.060579 | |
| 3adt5,"Estimation of Mechanical Parameters of Thin Films Using Finite Element Analysis","This study shows a methodology to estimate mechanical parameters of thin films by means of a bulge test and a numerical approach. The methodology is based on the combination of finite element analysis with a classical analytical method. Finite element modeling was conducted for monolayer (Si3N4) membranes of 2x2mm with the aim to approximate both the load-deflection curves experimentally measured and the classical load-deflection analytical model. Error functions were constructed and minimized to delimit a coupled solution space between Young’s modulus and Poison’s ratio. In a traditional bulge test analysis only one of the elastic properties can be determined due to that there is not unique solution in the estimations of these parameters. However, both elastic parameters were determined through the proposed numerical procedure which compares the deformed surfaces for a specific set of optimal elastic parameters computed. Results show that the estimated elastic properties agree with corresponding values determined by other methods in the literature",1,https://api.osf.io/v2/files/5c34f7cde8da0e001852d442/,325,https://engrxiv.org/3adt5/,10.31224/osf.io/3adt5,,2019-01-08T19:29:21.021314,2019-01-15T11:57:03.347504 | |
| qypw4,"Numerical Modeling Approach for the Assessment of Elastic Properties of bi-layer Thin Films Measured by Bulge Test","The present work shows a load-deflection bulge test method to characterize mechanical parameters of thin films by means of a numerical modelling approach. A methodology based on the combination of finite element analysis and classical analytical equations is presented and discussed. Finite element modeling was conducted for monolayer (Si3N4) and bi-layer (Si3N4/Al) membranes with the aim to determine a set of elastic parameters (Young's modulus and Poisson's ratio) which satisfied the load-deflection curves experimentally measured by the bulge test method. It is well known that in a traditional bulge test analysis only biaxial elastic modulus, i.e. a combination of Young's modulus and Poisson's ratio, can be determined. It is due to the mechanical coupling that exists between the two elastic parameters. However, in this study both mentioned elastic constants can be determined independently through a proposed numerical procedure that includes error functions for minimizing the displacement with a specific set of optimal elastic parameters. Results shows that the estimated Young's modulus (Al 64 GPa and Si3N4 236 GPa) agree with corresponding values determined by other methods in the literature of the studied thin films.",1,https://api.osf.io/v2/files/5c34cabb7cf3f50019b30e34/,305,https://engrxiv.org/qypw4/,10.31224/osf.io/qypw4,,2019-01-08T16:23:37.174836,2019-01-08T19:33:23.362069 | |
| hbj6d,"Optimal operation of renewable energy irrigation system using particle swarm optimization","In rural areas which are located far from the electrical grid, renewable energy systems such as photovoltaic (PV) energy are investigated. The most popular PV application is solar water pumping for irrigation. DC-DC converter and maximum power point tracking are used because the PV modules output varies widely due to varying weather conditions. The water pump is driven by a three phase induction motor through a voltage source inverter (VSI). However, the control of induction motor is known to be difficult because it's highly non-linear and time variant. One method to mitigate this is by using vector control techniques to control the VSI as they offer a number of benefits including speed control and regulation over a wide range and fast dynamic response. The proportional - integral (PI) controller is most commonly used in the speed control loop of vector control. This paper deals with the design of the speed PI controller parameters (gains) using particle swarm optimization (PSO) technique and compares it with the conventional Ziegler-Nichols (ZN) method. Different objective functions have been proposed which are used to evaluate the optimization algorithm. The optimum solution mainly converges to a minimum error which affects the control parameters such as the maximum overshoot, rise time and settling time of the system. Simulation results are obtained using Matlab/Simulink program for photovoltaic pump application during load variation (pump head and flow rate variation). The results show the advantage of the PSO-based optimization approach.",1,https://api.osf.io/v2/files/5c3444a8804708001af60128/,480,https://engrxiv.org/hbj6d/,10.31224/osf.io/hbj6d,,2019-01-08T06:43:59.601092,2019-01-08T13:34:48.990092 | |
| 7j8mg,"Battery energy storage for variable speed photovoltaic water pumping system","The photovoltaic (PV) solar electricity is no longer doubtful in its effectiveness in the process of rural communities’ livelihood transformation with solar water pumping system being regarded as the most important PV application. To overcome the intermittent and uncertain nature of solar power output, the highly fluctuating load demands and to supply loads at night time, a battery storage system is optimally sized, designed and implemented. The bi-directional Buck-Boost converter use and control are essential for energy management between the batteries and the pumping system. Domestic loads power calculation is also demonstrated and varied. Additionally, various inverter control schemes are examined and employed depending on the nature of the load connected. Finally, simulation results using Matlab/Simulink are presented for two cases: when the battery system is connected with the PV array to feed the pump motor to achieve the required varying hydraulic performance (flow rate and pumping head) under different weather conditions, and when the battery system feeds the loads while the PV array is disconnected at night.",1,https://api.osf.io/v2/files/5c333c5ae8da0e001a52084e/,397,https://engrxiv.org/7j8mg/,10.31224/osf.io/7j8mg,,2019-01-07T11:54:14.585631,2019-01-08T15:07:46.140215 | |
| cnm35,"High-Precision Laser Conditioning of Diamond Grinding Wheels","A novel approach for machining of cylindrical hard materials and arbitrary shapes is presented. Diamond grinding tools with complex geometry are manufactured with picosecond orthogonal and quasi-tangential combined laser ablation. This rapid and flexible approach for small-scale production of master tools for industrial production trumps conventional approaches. Hitherto, the overall process time is faster compared to conventional technologies with the benefit of free standing diamond grains. A laser manufacturing chain achieving an ablation rate of 35mm3/min with a maximal geometric deviation of 3μm is presented. The meta-stable diamond structure persists and is assessed via Raman spectroscopy. The final grinding tools is sharpened by a radial laser process removing preferentially the metal-based binding material. This isolates the statistically distributed diamond grains from the binder. Hence, high-precision diamond grinding wheels with a mean error of smaller 1μm over the complete contour can be manufactured.",1,https://api.osf.io/v2/files/5c327517e8da0e001752c67f/,544,https://engrxiv.org/cnm35/,10.31224/osf.io/cnm35,,2019-01-06T21:47:20.407058,2019-09-05T17:21:28.031856 | |
| 6nckp,"Temporal case study of household behavioural response to Cape Town's Day Zero using smart meter data","Faced with the threat of ""Day Zero"", when it was feared that Cape Town's taps could run dry, consumers reduced household water usage from 540 to 280 litres per household per day over the 36 months between January 2015 and January 2018. This paper describes the events that prompted this reduction. We look at how changes in water use were affected by official announcements and by public engagement with this news via the social media activity and internet searches. | |
| We analysed the water usage of a subset of middle to high income households where smart hot and cold water meters were installed. For hot water usage patterns we compared meter readings with that in another area unaffected by the drought. We further map our cold water smart meter readings against that of the City of Cape Town's municipal data for domestic freestanding households --- a sample of more than 400,000 households. We found that the introduction of Level 5 restrictions had a perverse effect on consumption, possibly due to confusing messages. The most dramatic change in behaviour appears to have been instigated by a media storm and consequent user panic after the release of the City's Critical Water Shortages Disaster Plan in October 2017. However, contradictory communication from national and provincial government eroded some of this gain. The paper concludes with recommendations for demand management in a similar future scenario.",1,https://api.osf.io/v2/files/5c311bb4e8da0e0017519400/,476,https://engrxiv.org/6nckp/,10.31224/osf.io/6nckp,10.1016/j.watres.2018.11.035,2019-01-05T21:09:00.090482,2019-05-26T09:31:55.560634 | |
| 23fzc,"A potential source of undiagnosed Legionellosis: Legionella growth in domestic water heating systems in South Africa","Legionella is a genus of pathogenic bacterial mesophiles that cause a range of diseases collectively referred to as Legionellosis, with immuno-compromised individuals being particularly susceptible. | |
| Water heaters, a potential domestic niche for these pathogens, are heavy energy consumers, causing cost-sensitive users to employ energy-saving initiatives, such as scheduling and lower temperature set points. However, lower water temperatures allow Legionella to flourish. This paper uses computational fluid dynamics modelling to show that a horizontal electric water heater provides an environment that is conducive to Legionella growth, although its prevalence is probably higher in the downstream pipes. The presence of Legionella in water heaters is established through water sampled from five in-field water heaters, of which the temperatures and heating schedules are known. Microbiological techniques (PCR and weight-based qRT-PCR) are used to assess the presence of Legionella and Legionella pneumophila at point-of-use taps. A model is used to determine the potential infection rate from these concentrations, demonstrating that undiagnosed Legionellosis infection is likely. | |
| In low- and middle-income countries, like South Africa, misdiagnosis of Legionellosis may be common due to the shadow cast by HIV and TB prevalence.",1,https://api.osf.io/v2/files/5c31165c8047080018f511b7/,430,https://engrxiv.org/23fzc/,10.31224/osf.io/23fzc,10.1016/j.esd.2018.12.001,2019-01-05T20:53:18.187750,2019-01-05T21:03:42.334658 | |
| f7st3,"Detecting high indoor crowd density with Wi-Fi localization: A statistical mechanics approach","We address the problem of detecting highly raised crowd density in situations such as indoor dance events. | |
| We propose a new method for estimating crowd density by anonymous, non-participatory, indoor Wi-Fi localization of smart phones. Using a probabilistic model inspired by statistical mechanics, and relying only on big data analytics, we tackle three challenges: (1) the ambiguity of Wi-Fi based indoor positioning, which appears regardless of whether the latter is performed with machine learning or with optimization, (2) the MAC address randomization when a device is not connected, and (3) the volatility of packet interarrival times. | |
| The main result is that our estimation becomes more -- rather than less -- accurate when the crowd size increases. This property is crucial for detection of dangerous crowd density.",1,https://api.osf.io/v2/files/5c2f4d5d384c8a001c575e97/,675,https://engrxiv.org/f7st3/,10.31224/osf.io/f7st3,10.1186/s40537-019-0194-3,2019-01-04T12:25:48.617969,2019-04-07T19:38:27.160298 | |
| v3z6a,"Clustering image noise patterns by embedding and visualization for common source camera detection","We consider the problem of clustering a large set of images based on similarities of their noise patterns. Such clustering is necessary in forensic cases in which detection of common source of images is required, when the cameras are not physically available. We propose a novel method for clustering combining low dimensional embedding, visualization, and classical clustering of the dataset based on the similarity scores. We evaluate our method on the Dresden images database showing that the methodology is highly effective.",1,https://api.osf.io/v2/files/5c2df2120e8efd0017d27d14/,436,https://engrxiv.org/v3z6a/,10.31224/osf.io/v3z6a,10.1016/j.diin.2017.08.005,2019-01-03T12:14:19.163750,2019-01-08T15:55:02.797380 | |
| g7vkb,"A Research Framework for Supervised Image Classification For Tornado Chaos Phenomena","Unattended classification is a classification which is the process of forming classes conducted by computers. The classes formed in this classification are highly dependent on data acquisition. In the process, this classification classifies pixels based on similarity or spectral similarity. While the supervised classification is a classification carried out by the analyst's direction. The l purpose of this study is to build a new model of image-based classification based on chaos phenomena through remote sensing to detect the beginning of the emergence of tornadoes. This research optimizes the search for the best value from a data collection of samples of chaos phenomena in tornadoes through a new model called Citra which is supervised by Chaos Discrete Cosine Transform Spectral Angel Mapper Classification (SiChDCosTSamC). The resulting model can then be used as remote sensing to detect the appearance of the initial tornado. Tests will be carried out using the Protected Image Welding on models based on chaotic / chaotic phenomena. Testing will be carried out on a collection of sample image data sourced from SIO, NOAA, US data. Navy, NGA, GEBCO U.S. PGA / NASA Google IBCAO | |
| Geological Geological Survey / Copernicus",1,https://api.osf.io/v2/files/5c2dcbe30e8efd0016ce35df/,367,https://engrxiv.org/g7vkb/,10.31224/osf.io/g7vkb,,2019-01-03T08:58:25.290431,2019-01-03T17:59:38.421473 | |
| dru2e,"IoT Based Smart Garbage Monitoring System","This project IOT Based Garbage Monitoring | |
| System is a very smart system which will help to keep our | |
| village and cities. We see that in our cities public dustbins | |
| are overloaded and it create unhygienic conditions for | |
| people and That place leaving a bad smell. To avoid all | |
| these things we are Going to implement a project IOT | |
| based garbage monitoring System. These dustbins are | |
| interfaced with Arduino base system having ultrasonic | |
| sensor along with central system showing the Current | |
| status of garbage on display and web browser HTML page | |
| with Wi-Fi module. To increase the cleanness in the | |
| country government started the various project. This | |
| project is helpful for government project of “SWACHH | |
| BHARAT ABHIYAN”.",1,https://api.osf.io/v2/files/5c2ba1fe0e8efd0019cdc979/,719,https://engrxiv.org/dru2e/,10.31224/osf.io/dru2e,,2019-01-01T17:25:37.720729,2019-01-01T20:05:55.040981 | |
| xzv56,"Comparison of Various Encryption Algorithms for Securing Data","Data encryption is the process of protecting information. It protects its availability, privacy and integrity. To write this article we have study about information security using cryptography technique. After the analyzing different techniques of encryption, we are proposing Advance Encryption Standard (AES). The AES has the better security compared others encryption algorithm and prevent data from Spoofing. It is very efficient in both hardware and software.",1,https://api.osf.io/v2/files/5c2b0d080e8efd0016cd04e9/,379,https://engrxiv.org/xzv56/,10.31224/osf.io/xzv56,,2019-01-01T06:49:11.987944,2019-01-01T15:08:35.305419 | |
| cgpq9,"Humidification requirements in economizer-type HVAC systems","We develop a formulation to compute the maximum humidification load for economizer-type HVAC systems. The resulting formulae can be used, together with ASHRAE-provided climate data, to find the maximum humidification load in both temperature-based and enthalpy-based economizer systems. | |
| ASHRAE Transactions 119(1) (2013)",1,https://api.osf.io/v2/files/5c2ac56b28af78001967f19f/,374,https://engrxiv.org/cgpq9/,10.31224/osf.io/cgpq9,,2019-01-01T02:06:28.373747,2019-01-01T18:30:06.638755 | |
| ndm7f,"Beyond signal quality: The value of unmaintained pH, dissolved oxygen, and oxidation-reduction potential sensors for remote performance monitoring of on-site sequencing batch reactors","Sensor maintenance is time-consuming and is a bottleneck for monitoring on-site wastewater treatment systems. Hence, we compare maintained and unmaintained pH, dissolved oxygen (DO), and oxidation-reduction potential (ORP) sensors to monitor the biological performance of a small-scale sequencing batch reactor (SBR). We created soft sensors using engineered features: ammonium valley for pH, oxidation ramp for DO, and nitrite ramp for the ORP. We found that the pH soft sensors are able to reliably identify the completion of ammonium oxidation in the SBR’s effluent even without sensor maintenance for over a year. In contrast, the DO soft sensor using data from a maintained sensor showed slightly better detection performance than that using data from unmaintained sensors, as the DO soft sensor using maintained data is much less sensitive to the optimisation of cut-off frequency and slope tolerance than the soft sensor using unmaintained data. The nitrite ramp provided no useful information on the state of nitrite oxidation, so no comparison of maintained and unmaintained ORP sensors was possible in this case. We identified two hurdles when designing soft sensors for unmaintained sensors: i) Sensors’ type- and design-specific deterioration affects performance. ii) Feature engineering for soft sensors is sensor type specific, and the outcome is strongly influenced by operational parameters such as the aeration rate. In summary, we provide soft sensors that allow the performance of unstaffed small-scale SBRs to be monitored with unmaintained sensors and therefore the maintenance and reliability of OST systems to be optimised.",1,https://api.osf.io/v2/files/5c29619c0e8efd0017ced460/,569,https://engrxiv.org/ndm7f/,10.31224/osf.io/ndm7f,10.1016/j.watres.2019.06.007,2018-12-31T00:33:09.264681,2019-07-04T19:16:20.567762 | |
| nykuh,"Adaptive smartphone-based sensor fusion for estimating competitive rowing kinematic metrics","Competitive rowing highly values boat position and velocity data for real-time feedback during training, racing and post-training analysis. The ubiquity of smartphones with embedded position (GPS) and motion (accelerometer) sensors motivates their possible use in these tasks. In this paper, we investigate the use of two real-time digital filters to achieve highly accurate yet reasonably priced measurements of boat speed and distance traveled. Both filters combine acceleration and location data to estimate boat distance and speed; the first using a complementary frequency response-based filter technique, the second with a Kalman filter formalism that includes adaptive, real-time estimates of effective accelerometer bias. The estimates of distance and speed from both filters were | |
| validated and compared with accurate reference data from a differential GPS system with better than 1 cm precision and a 5 Hz update rate, in experiments using two subjects (an experienced club-level rower and an elite rower) in two different boats on a 300 m course. Compared with single channel (smartphone GPS only) measures of distance and speed, the complementary filter improved the accuracy and precision of boat speed, boat distance traveled, and distance per stroke by 44%, 42%, and 73%, respectively, while the Kalman filter improved the accuracy and precision of boat speed, boat distance traveled, and distance per stroke by 48%, 22%, and 82%, respectively. Both filters demonstrate promise as general purpose methods to substantially improve estimates of important rowing performance metrics.",1,https://api.osf.io/v2/files/5c1fce877cd9be001c5c6caa/,674,https://engrxiv.org/nykuh/,10.31224/osf.io/nykuh,,2018-12-23T18:10:49.311667,2019-11-17T01:43:31.069780 | |
| xmsqf,"Methods In Seeing The Completion Of the Grand Electric Renaissance Dam (GERD)","Full analysis of the GERD Project and method for monitoring the project and seeing its completion.",1,https://api.osf.io/v2/files/5c1d399e7cd9be001c5b9309/,856,https://engrxiv.org/xmsqf/,10.31224/osf.io/xmsqf,,2018-12-21T19:07:32.009232,2018-12-22T18:54:27.018211 | |
| mv6tz,"Characterizing Long-term Wear and Tear of Ion-Selective pH Sensors","The development and validation of methods for fault detection and identification in wastewater treatment research today relies on two important assumptions: {\em (i)} that sensor faults appear at distinct times in different sensors and {\em (ii)} that any given sensor will function near-perfectly for a significant amount of time following installation. In this work, we show that such assumptions are unrealistic, at least for sensors built around an ion-selective measurement principle. Indeed, long-term exposure of sensors to treated wastewater shows that sensors exhibit important fault symptoms that appear simultaneously and with similar intensity. Consequently, our work suggests that focus of research on methods for fault detection and identification should be reoriented towards methods that do not rely on the assumptions mentioned above. This study also provides the very first empirically validated sensor fault model for wastewater treatment simulation and we recommend its use for effective benchmarking of both fault detection and identification methods and advanced control strategies. Finally, we evaluate the value of redundancy for the purpose of remote sensor validation in decentralized wastewater treatment systems.",1,https://api.osf.io/v2/files/5c17c3e31f10eb0018599546/,377,https://engrxiv.org/mv6tz/,10.31224/osf.io/mv6tz,,2018-12-17T15:47:47.135166,2018-12-19T14:19:31.914956 | |
| g3djq,"Partial Molar Volume of NaCl and CsCl in Mixtures of Water and Methanol by Experiment and Molecular Simulation","Densities of solutions of NaCl and CsCl in mixtures of water and methanol | |
| are determined by experiment and molecular dynamics simulation. Both experiments | |
| and simulations cover the concentration range up to the solubility | |
| limit of the salt in the temperature range 288.15 ? T / K ? 318.15 at ambient | |
| pressure. Non-polarizable molecular models from the literature are used | |
| for the ions and solvents. The partial molar volume of the salts at in?nite | |
| dilution in the mixed solvent is determined from an empirical correlation of | |
| the data. The mixed solvent e?ects on the density and the partial molar | |
| volumes of the salts are well predicted by the molecular models.",1,https://api.osf.io/v2/files/5c1765db7b16bf0017af177b/,1124,https://engrxiv.org/g3djq/,10.31224/osf.io/g3djq,10.1016/j.fluid.2017.10.034,2018-12-17T09:04:31.603243,2018-12-17T16:55:53.788926 | |
| gmp2h,"Electrospun polymeric nanofibrous membranes for water treatment","A necessity for water filtration technology, due to global pollution and population growth, has led to an increase in attention to advanced nanomaterials that can aid in the purification of air and water. This size-dependent filtration is possible via nanofibrous membranes as they contain high porosity and this pore size is tunable through the fabrication process. Because of this tunability in the nanofibril membrane composition and structure, they possess promising straining abilities, such as high permeability and selectivity, as well as low fouling. There are a variety of polymer blends or organic/inorganic nanofillers that can be used depending on filtration needs. The production of nanofibers consists of various avenues such as synthetic templates, separation by different phases, nanoparticle self-assembly, and most widespread, electrospinning. Electrospinning is prevalent owing to its ease of use and low cost compared to template and self- assembly processes. This chapter describes the multifaceted progression governing electrospinning and its working factors as well as the environmental settings that form nanofibers and their resultant membranes. Additionally, the various designs of electrospinning apparatuses' and review of the methods used to prepare multifunctional composite electrospun nanofibrous membranes will be discussed. Past achievements and current challenges will be provided. Conclusions and perspectives are specified fitting to studied progress so far as well as future needs with regards to water treatment, with a particular focus on industrial applications.",1,https://api.osf.io/v2/files/5c16670be979520017e392ab/,1235,https://engrxiv.org/gmp2h/,10.31224/osf.io/gmp2h,,2018-12-16T15:03:55.203788,2019-05-07T00:23:18.903316 | |
| yhkeq,"FTP Security with Sockets","File Transfer Protocol (FTP), is a standard network protocol used to transfer files from one host to another host over a Transmission Control Protocol (TCP), based network such as internet. This protocol can be used to upload or download files form one host to another. This protocol is based on client-server architecture. | |
| This article is about the security issues in FTP i.e., bounce attack, brute force, spoof attack and port stealing etc. Port Stealing is an issue in FTP that enables cyber criminals to steal data in transit. In this document we will be presenting a novel way to solve this problem by using Sockets and will secure information using encryption techniques to encrypt the data in transit.",1,https://api.osf.io/v2/files/5c100bec6be62d001a46f40a/,202,https://engrxiv.org/yhkeq/,10.31224/osf.io/yhkeq,,2018-12-11T19:12:37.945822,2018-12-17T16:53:32.256103 | |
| 2wrh5,"Routing Protocols and Their Limitations","Routing protocols define how routers communicate with each other. They calculate the path taken by the data travelling in a network. This article discusses routing protocols and how they work. Then it defines the characteristics an ideal routing protocol should have and the problems faced by routing protocols right now. The article ends with an exploration and discussion of types of routing protocols.",1,https://api.osf.io/v2/files/5c100b176be62d001946b61d/,957,https://engrxiv.org/2wrh5/,10.31224/osf.io/2wrh5,,2018-12-11T19:09:10.977483,2018-12-17T16:52:56.372969 | |
| b38ze,"Performance Improvement in TCP","Transmission Control Protocol (TCP), the most popular transport layer communication protocol for the Internet.It was originally designed for wired networks, where Bit Error Rate (BER) is low and congestion is the primary cause of packet loss [1].This article analyzes the issues in TCP, such as slow start, congestion control, collisions, low BER etc. Then it provides systematic analysis the issues regarding to wireless network i.e., Head of Line Blocking. At the end it proposes solution forTCP enhancement specific to wireless network.",1,https://api.osf.io/v2/files/5c100a3ae070780018745446/,303,https://engrxiv.org/b38ze/,10.31224/osf.io/b38ze,,2018-12-11T19:05:25.284783,2018-12-17T16:52:10.497026 | |
| y3abr,"Frequency Hopped Spread Spectrum Tutorial","This article is about FHSS (Frequency Hopped Spread Spectrum) and one method suggested for Security improvement in it. In this report you can find an in depth information on FHSS from the basic level to the aim of the project. A detailed explanation is given about the Modulation, Frequency Hopping, PN-sequence generation, Frequency table w.r.t PN sequence which form crucial components in generation of the FH-spread signal. And finally demodulation is done and the obtained waveforms are analyzed. The whole process is simulated in the well-known simulator MATLAB. Working code is attached with this report. One method is suggested to improve the security in the FHSS.",1,https://api.osf.io/v2/files/5c0ff74d6be62d001b46339e/,450,https://engrxiv.org/y3abr/,10.31224/osf.io/y3abr,,2018-12-11T17:44:41.926031,2018-12-11T18:12:51.561408 | |
| 972af,"Smart Agriculture System","We are now embracing the 4th Industrial revolution. Everything is connected, smart and responsive. | |
| With that many new devices being connected to the grid we need a new way of connecting them. We will be working in the context of low power sensors used for data logging. One thing we will keep referring to is smart agriculture sensor systems. | |
| To connect these many smart agricultural sensors to the grid we propose the use of wireless meshed networks. Since these are portable and potentially reusable sensors it would be a waste of resources to connect each sensor to the internet individually. Since the sensors can in many scenarios be disposable we can a resource and eco-friendly way to connect these sensors to some permanent fixed stations that are used for data collection and measurements.",1,https://api.osf.io/v2/files/5c0fefca6be62d001a46ded7/,323,https://engrxiv.org/972af/,10.31224/osf.io/972af,,2018-12-11T17:13:14.616921,2018-12-11T17:40:26.565144 | |
| t8rjk,"IEEE 802.11 Tutorial","IEEE 802.11 is a set of media access control (MAC) and physical layer (PHY) specifications for implementing wireless local area network (WLAN) computer communications. Maintained by the Institute of Electrical and Electronics Engineers (IEEE) LAN/MAN Standards Committee (IEEE 802). This document highlights the main features of IEEE 802.11n variant such as MIMO, frame aggregation and beamforming along with the problems in this variant and their solutions",1,https://api.osf.io/v2/files/5c0eb1f29cdb9f0016680270/,237,https://engrxiv.org/t8rjk/,10.31224/osf.io/t8rjk,,2018-12-10T18:36:37.351781,2018-12-11T16:47:30.291712 | |
| q4egs,"Towards Implementing IS-IS","This report briefly describes routing and then explains what is IS-IS routing protocol and how IS-IS works.",1,https://api.osf.io/v2/files/5c0defc09cdb9f0016671dcb/,148,https://engrxiv.org/q4egs/,10.31224/osf.io/q4egs,,2018-12-11T18:11:43.861031,2018-12-11T18:11:44.111258 | |
| 752jh,"Design and Modeling of Novel Low-Pressure Nanofiltration Hollow Fiber Modules for Water Softening and Desalination Pretreatment","Given its high surface area to volume ratio and desirable mass transfer characteristics, the hollow fiber | |
| module configuration has been central to the development of RO and UF technologies over the past five | |
| decades. Recent studies have demonstrated the development of a novel class of low-pressure nanofiltration | |
| (NF) hollow fiber membranes with great promise for scale-up implementation. Further progress on large-scale | |
| deployment, however, has been restrained by the lack of an accurate predictive model, to guide module design | |
| and operation. Earlier models targeting hollow fiber modules are only suitable for RO or UF. In this work, | |
| we propose a new modeling approach suitable for NF based on the implementation of mass and momentum | |
| balances, coupled with a validated membrane transport model based on the extended Nernst-Planck equation | |
| to predict module performance at the system-level. Modeling results are validated with respect to synthetic | |
| seawater experiments reported in an earlier work. A preliminary module design is proposed, and parametric | |
| studies are employed to investigate the effect of varying key system parameters and elucidate the tradeoffs | |
| available during design. The model has significant implications for low-pressure nanofiltration, as well as | |
| hollow fiber NF module design and operation.",1,https://api.osf.io/v2/files/5c0c40e66be62d001b446181/,629,https://engrxiv.org/752jh/,10.31224/osf.io/752jh,10.1016/j.desal.2018.04.002,2018-12-08T22:13:36.215143,2018-12-08T22:44:09.548874 | |
| pnkru,"Relating Transport Modeling to Nanofiltration Membrane Fabrication: Navigating the Permeability-Selectivity Trade-off in Desalination Pretreatment","Faced with a pressing need for membranes with a higher permeability and selectivity, the field of membrane | |
| technology can benefit from a systematic framework for designing membranes with the necessary | |
| physical characteristics. In this work, we present an approach through which transport modeling is employed | |
| in fabricating specialized nanofiltration membranes, that experimentally demonstrate enhanced selectivity. | |
| Specifically, the Donnan-Steric Pore Model with dielectric exclusion (DSPM-DE) is used to probe | |
| for membrane properties desirable in desalination pretreatment. Nanofiltration membranes are systematically | |
| fabricated in-house using layer-by-layer (LbL) deposition to validate model predictions and to develop a | |
| new specialized membrane for this application. The new membrane presents a 30% increase in permeability | |
| and a 50% reduction in permeate hardness relative to state-of-the-art NF membranes. Our results indicate | |
| that a ‘specialized’ tight membrane can outperform looser counterparts in both permeability and selectivity. | |
| Given the possibility of extending this framework to other applications, the work furthers our understanding | |
| of the relationships governing membrane form and function, while having broad potential implications for | |
| future nanofiltration membranes used in chemical separation and purification.",1,https://api.osf.io/v2/files/5c0c3c909cdb9f001665847f/,383,https://engrxiv.org/pnkru/,10.31224/osf.io/pnkru,10.1016/j.memsci.2018.02.053,2018-12-08T21:57:49.831528,2018-12-08T22:56:37.833660 | |
| j6v2c,"Study of the process of obtaining sorbents from bentonite clays using technogenic waste (Исследование процесса получения сорбентов из бентонитовых глин с использованием техногенных отходов)","To study the multifunctional sorption properties of local bentonite clays, physicochemical studies of the chemical, mineralogical, and phase characteristics of Darbazin clays and the intumescent oil sludge additive were conducted. Physico - chemical studies have established the contents of the mineral and organic part of sludge. As a result, it was found that paraffin-naphthenic and aromatic compounds predominate in the organic part, while compounds of silicon, calcium, aluminum and iron predominate in the mineral part. Studies on the method of modifying local bentonites with acid and heat treatment, which activate the sorption properties, due to the cation exchange of the initial elements of montmorillonite minerals. The method of temperature-reduction and desorption of hydrogen absorption region are set at °350C, 650°Cand stripping at 433C.° The thermodynamic studies of calculation of Gibbs energy of possible reactions with adsorbents synthetic minerals additive sludge found that the highest thermodynamic probability minerals characterized by synthesis in the presence of C6H6, and the smallest - in the presence of CH4. Для изучения многофункциональных сорбционных свойств местных бентонитовых глин проведены физико – химические исследования химических, минералогических и фазовых особенностей Дарбазинских глин и вспучивающей добавки нефтяных шламов. Физико – химическими исследованиями установлены содержания минерологической и органической части нефтешламов. В результате установлено, что в органической части преобладают парафинно – нафтеновые и ароматические соединения, а в минеральной части преобладают соединения кремния, кальция, алюминия и железа. Проведенные исследования метода модифицирования местных бентонитов кислотной и термической обработкой, которые активируют сорбционные свойства, за счет катионного обмена исходных элементов монтмориллонитовых минералов. Методом термопрограммированного восстановления и десорбции водорода установлены области поглощения при 350оC, 650оС и десорбции при 433оС. Термодинамическими исследованиями расчета энергии Гиббса возможных реакций синтеза минералов сорбентов с добавкой нефтешлама установлено, что наибольшей термодинамической вероятностью характеризуется синтез минералов в присутствии С6Н6, а наименьшей – в присутствии СН4.",1,https://api.osf.io/v2/files/5c0bd6986be62d0019444dc6/,364,https://engrxiv.org/j6v2c/,10.31224/osf.io/j6v2c,10.5281/zenodo.2076033,2018-12-10T15:10:53.136159,2018-12-10T15:10:53.190800 | |
| 9hvdp,"RESEARCH OF ENZYMATIC HYDROLYSIS PROCESSES OF WHEAT'S STRAW BY LIQUID CELLULOLYTIC ENZYMATIC AGENTS","Objective of this research was to investigate process of enzymatic hydrolysis of wheat's straw by liquid cellulolytic enzymatic preparations. At the first stage wheat straw has been subjected to autohydrolysis then the fibrous weight was washed out by water with reception of sugar solution. The following stage included extraction of disrupt lignin and modelling experiments for studying enzymatic kinetics was the last stage. As a result of the carried out researches it has been established, that that the maximum exit of reacting substances is observed 4,8 %, the minimum exit is 2,2 %. The general maintenance of carbohydrates in wheaten straw has made 83,3 % from weight of wheaten straw. Among monosaccharides in straw are prevailed xylose and glucose. Measurement of рН of the investigated wheaten straw in water at the hydromodule 1 : 5,8 has shown, that рН makes 7,2840±11. рН of straw presoaked in 0,59 % of weights to sulphurous acid has made 2,24±0,11. рН of the straw presoaked in 1,18 % of weights to sulphurous acid has made 1,48±0,10.",1,https://api.osf.io/v2/files/5c0bcf73e07078001871cd2d/,302,https://engrxiv.org/9hvdp/,10.31224/osf.io/9hvdp,10.5281/zenodo.2074793,2018-12-08T14:11:35.805875,2018-12-08T19:19:52.752467 | |
| pbyxz,"Micromechanics-based homogenization of the effective physical properties of composites with an anisotropic matrix and interfacial imperfections","Micromechanics-based homogenization has been employed extensively to predict the effective properties of technologically important composites. In this review article, we address its application to various physical phenomena, including elasticity, thermal and electrical conduction, electric and magnetic polarization, as well as multi-physics phenomena governed by coupled equations such as piezoelectricity and thermoelectricity. Especially, we introduce several research works published recently from our research group that consider the anisotropy of the matrix and interfacial imperfections in obtaining various effective physical properties. We begin with a brief review of the concept of the Eshelby tensor with regard to the elasticity and mean-field homogenization of the effective stiffness tensor of a composite with a perfect interface between the matrix and inclusions. We then discuss the extension of the theory in two aspects. First, we discuss the mathematical analogy among steady-state equations describing the aforementioned physical phenomena and explain how the Eshelby tensor can be used to obtain various effective properties. Afterwards, we describe how the anisotropy of the matrix and interfacial imperfections, which exist in actual composites, can be accounted for. In the last section, we provide a summary and outlook considering future challenges.",1,https://api.osf.io/v2/files/5c09c105a9b99c001816a6b2/,656,https://engrxiv.org/pbyxz/,10.31224/osf.io/pbyxz,,2018-12-07T00:47:11.618876,2019-01-19T00:17:16.669718 | |
| 6yz37,"Characterizing Engineering Work in a Changing World: Synthesis of a Typology for Engineering Graduates' Occupational Outcomes","The 21st century has brought an expansion in the variety of occupational roles associated with product, service, and technological development. As a result, it has become more challenging to assess the occupational choices of engineering graduates over time. This paper introduces an engineering graduates’ occupational outcomes typology designed to facilitate consistency among researchers who employ occupational outcome as a dependent variable in original research, such as in studies of underrepresented groups’ persistence in engineering. The typology is synthesized from the results of a systematic literature review aimed at establishing which work attribute(s) have most consistently united those practicing engineering. The review identifies “design responsibility” – responsibility for the outcomes of design implementation, inclusive of safety, ethicality, and general effectiveness of designs – as an enduring commonality among engineers. Subsequent stages of the review then uncover how this design responsibility has often manifested in engineering practice. Based on the literature review, we present a series of propositions that underpin general definitions of three types of occupational outcomes – engineering work, engineering-related work, and other work – showing how the types can be distinguished based on the nature of design responsibility associated with each. These definitions thus serve as the foundation for a stratified typology of occupations’ engineering-relatedness. We conclude by discussing how utilization of this stratified approach for measuring engineering graduates’ occupational outcomes can enhance transparency and consistency among studies that examine such outcomes. By building the typology upon a distilled notion of fundamental job responsibility, rather than upon job titles, it is our hope that the typology can serve in a meaningful, enduring occupational benchmarking capacity as new job titles, role formulations, or entire technology areas, come and go.",1,https://api.osf.io/v2/files/5c095b13ecd5e1001a013150/,436,https://engrxiv.org/6yz37/,10.31224/osf.io/6yz37,,2018-12-06T17:26:35.366641,2018-12-06T18:46:25.160850 | |
| gvz46,"Electrophoretic deposition of LiFePO4 for Li-ion batteries","An electrophoretic deposition (EPD) method has been developed for the deposition of LiFePO4-carbon black films for application in Li-ion batteries. The approach is based on the use of poly[1-[4-(3-carboxy-4-hydroxyphenylazo)benzenesulfonamido]-1,2-ethanediyl, sodium salt] (PAZONa) and carboxymethyl cellulose sodium salt (CMC-Na), as dispersing, charging and film forming agents. The individual monomers of PAZO-Na and CMC-Na created multiple bonds with metal atoms on the particle surface and allowed for efficient electrosteric dispersion and charging of relatively large commercial LiFePO4 particles. The microstructure, deposition mechanism and electrochemical performance were investigated. The LiFePO4 electrode, prepared by the EPD method, exhibited a capacity of 146.7 mAh g-1 at C/10 and enhanced cycling stability.",1,https://api.osf.io/v2/files/5c087124d5d9eb0019c70ebd/,176,https://engrxiv.org/gvz46/,10.31224/osf.io/gvz46,,2018-12-06T00:48:09.283131,2018-12-06T14:59:44.167653 | |
| h5rtc,"DoS Attacks at Cooperative MAC","—Cooperative networking brings performance improvement to most of the | |
| issues in wireless networks, such as fading or delay due to slow stations. However, due to | |
| cooperation when data is relayed via other nodes, there network is more prone to attacks. | |
| Since, channel access is very important for cooperation, most of the attacks happens at MAC. | |
| One of the most critical attack is denial of service, which is reason of cooperation failure. | |
| Therefore, the cooperative network as well as simple wireless LAN must be defensive against | |
| DOS attacks. | |
| In this article we analyzed all possible of DoS attacks that can happen at MAC layer of | |
| WLAN. The cooperative protocols must consider defense against these attacks. This article | |
| also provided survey of available solutions to these attacks. At the end it described its | |
| damages and cost as well as how to handle these attacks while devising cooperative MAC.",1,https://api.osf.io/v2/files/5c080f9254cd090019f35b86/,357,https://engrxiv.org/h5rtc/,10.31224/osf.io/h5rtc,,2018-12-05T17:50:51.210183,2018-12-05T18:14:51.151968 | |
| m5x6t,"Influence of blends of diesel and renewable fuels on CI engine emissions over transient engine conditions.","To reduce the amount of carbon dioxide released from transportation the EU has implemented legislation to mandate the renewable content of petrol and diesel fuels. However, due to the complexity of the combustion process the addition of renewable content, such as biodiesel and ethanol, can have a detrimental effect on other engine emissions. In particular the engine load can have a significant impact on the emissions. Most research that have studied this issue are based on steady state tests, that are unrealistic of real world driving and will not capture the difference between full and part loads. This study aims to address this by investigating the effect of renewable fuel blends of diesel, biodiesel and ethanol on the emissions of a compression ignition engine tested over the World Harmonised Light Vehicle Test Procedure (WLTP). Diesel, biodiesel and ethanol were blended to form binary and ternary blends, the ratios were determined by Design of Experiments (DoE). The total amount of emissions for CO, CO2 and NOx as well as the fuel consumption, were measured from a 2.4 liter compression ignition (CI) engine running over the WLTP drive cycle. The results depicted that percentages smaller than 10 % of ethanol in the fuel blend can reduce CO emissions, CO2 emissions as well as NOx emissions, but increases fuel consumption with increasing percentage of ethanol in the fuel blend. Blends with biodiesel resulted in minor increases in CO emissions due to the engine being operated in the low and medium load regions over the WLTP. CO2 emissions as well as NOx emissions increased as a result of the high oxygen content in biodiesel which promoted better combustion. Fuel consumption increased for blends with biodiesel as a result from biodiesel's lower heating value. All the statistical models describing the engine responses were significant and this demonstrated that a mixture DoE is suitable to quantify the effect of fuel blends on an engine's emissions response. An optimised ternary blend of B2E9 was found to be suitable as a 'drop in' fuel that will reduce harmful emissions of CO emissions by approximately 34 %, NOx emissions by 10 % and CO2 emissions by 21 % for transient engine operating scenarios such as the WLTP drive cycle.",1,https://api.osf.io/v2/files/5c07ae69918cc70017c7d468/,414,https://engrxiv.org/m5x6t/,10.31224/osf.io/m5x6t,10.1016/j.apenergy.2019.113890,2018-12-05T11:28:30.109333,2019-09-19T21:14:52.520520 | |
| gt7p2,"Radial basis neural tree model for improving waste recovery process in a paper industry","In this article, we propose a novel hybridization of regression trees (RT) and radial basis function networks (RBFN), namely, radial basis neural tree (RBNT) model, | |
| for waste recovery process improvement in the paper industry. As a by-product of the paper manufacturing process, a lot of waste along with valuable fibers and fillers | |
| come out from the paper machine. The waste recovery process (WRP) involves separating the unwanted materials from the valuable ones so that the recovered fibers | |
| and fillers can be further reused in the production process. This job is done by fiber-filler recovery equipment (FFRE). The efficiency of FFRE depends on several | |
| crucial process parameters and monitoring them is a difficult proposition. The proposed model can be useful to find the essential parameters from the set of available | |
| data and perform prediction task to improve waste recovery process efficiency. An idea of parameter optimization along with regularity conditions for the universal consistency of the proposed model are given. The proposed model has the advantages of easy interpretability and excellent performance when applied to the FFRE | |
| efficiency improvement problem. Improved waste recovery will help the industry to become environmentally friendly with less ecological damage apart from being cost-effective.",1,https://api.osf.io/v2/files/5c0614dc65e965001bddc9a1/,354,https://engrxiv.org/gt7p2/,10.31224/osf.io/gt7p2,,2018-12-04T05:51:51.609758,2018-12-04T14:54:03.778425 | |
| wdt3g,"IPv6 Modeling in E-ID Cards as Efficiency Efforts in the Population Registration Process","In order to be registered in an institution / organization, each resident / community must register by providing identity data personally. When someone wants to be registered in an institution such as Birth Certificate, School, College, residence, Tax, BPJS, Bank, Driver Lisence, Passport and others, they must register and register one by one and have a registration number or account for each agency. It can be said that nowadays everyone is bothered with the registration process, starting from the time of birth they must register to be registered as residents, to enter the school must also register, this is felt to be ineffective and inefficient because one must continue to register one by one and redundancy have a registration number that is different for each agency. | |
| The presence of an electronic resident card (e-KTP) aims to make data collection easier and there is no double KTP number, but this is not yet maximal, there are still multiple KTP numbers, proven by many multiple data communities. Seeing these problems need to find a solution or an effort to ensure that the affairs of registration are not repeated and once up and the number is valid for all agencies. The presence of the latest technology namely IP v6 (Internet Protocol) brings the opportunity for the efficiency and effectiveness of the registration system, because IP v6 is able to provide numbers up to trillions addressing numbers. The objectives of this study are: 1) Designing an analytical model to build an IP V6 model on e-KTP registration. 2) Application of one IP v6 model on e-KTP registration using IPv6 IP address, once the child is born automatically has one registration number i.e. IPv6 address number, and the number applies to all agencies. The method used in this study is an exploration and modeling study of system development with NDLC to produce a model for building IP v6 implementation on e-KTP. The results of the study will show that the community has one registration number, namely IP v6, and the number is valid since the child is born and for all agencies such as birth certificates, e-KTP, Student Number, Passport, Driver’s License, Bank and others The results of the study that implemented IPv6 on numbering e-KTP with a total length of 128 bits, greatly facilitated citizens in terms of registration services because each resident only has one identification number will apply to all agencies, because there is no data repetition or data redundancy, one e-ID card can be applied to elementary schools, high schools, hospitals, BPJS, Driver’s License, passports and for communication addressing or IP addresses to be part of the e-KTP.",1,https://api.osf.io/v2/files/5c02461eb7ef1400164b8d22/,349,https://engrxiv.org/wdt3g/,10.31224/osf.io/wdt3g,,2018-12-01T08:36:27.066011,2018-12-02T22:03:14.166310 | |
| gzaqe,"Universally consistent hybrid regression model for water quality prediction","In this work, we propose a hybrid regression model to solve a specific problem faced by a modern paper | |
| manufacturing company. Boiler inlet water quality is a major concern for the company since it helps to | |
| produce power and steam for the paper machine. If water treatment plant can not produce water of desired | |
| quality as specified by the boiler, then it results in poor health of the boiler water tube and consequently | |
| affects the quality of the paper. Variation in inlet water quality of the boiler is due to several crucial process | |
| parameters. We build a hybrid regression model for boiler water quality prediction based on decision trees | |
| and artificial neural networks. This model can be useful for manufacturing process quality improvement | |
| for the paper company. We have proved the desired statistical consistency of the hybrid model to show | |
| its robustness and universal use. The primary advantage of the model is its natural interpretability and | |
| excellent performance when compared with other state-of-the-art.",1,https://api.osf.io/v2/files/5c0119d2b7ef1400164a23d9/,332,https://engrxiv.org/gzaqe/,10.31224/osf.io/gzaqe,,2018-11-30T11:12:43.992373,2019-02-19T11:17:24.345721 | |
| dgj97,"Spray characteristics of a fuel–water internally rapid mixing injector for burner combustion","The fuel-water internally rapid mixing type of injector has been developed to reduce NOx and soot emissions from combustion furnaces operating under high-load conditions. The injector allows spray injection of water emulsified fuel originating from base fuel and water without any surfactants. The aim of present study is to elucidate the mechanism of emulsification occurring in the injector and the atomization characteristics of the injector. We measured the sizes of fuel droplets discharged from the injector by means of a high-speed shadowgraph method combined with image processing. Soybean oil was used as the base fuel. The flow patterns of the fuel and water in a transparent mixing chamber of the injector were also visualized. In addition, we investigated the inner structure of the large droplets sampled by an immersion droplet sampling method. The base fuel, water and air are separately introduced into the injector. In the mixing chamber of the injector, fuel and water are blown by swirling air, and then impinge on the inner wall of the chamber. The base fuel is emulsified through the mixing of fuel with water resulting from the impingement. The emulsified fuel moves to injection holes along the inner wall, and is finally discharged through the injection holes with atomizing air. The probability profiles of droplet size exhibit that the existence probabilities of coarse droplets with diameters greater than approximately 35 mm are increased when the fuel is emulsified. Although the emulsification deteriorates the atomization capability of the injector, the secondary atomization including the micro-explosion occurring in combustion furnaces would form fine droplets, and thus reducing the soot emission from the furnaces. The microscope observations revealed that the emulsified fuel filling in a large droplet sampled corresponds to W/O type.",1,https://api.osf.io/v2/files/5c00c81e022ce90017141ff7/,307,https://engrxiv.org/dgj97/,10.31224/osf.io/dgj97,,2018-11-30T05:38:20.538580,2019-09-16T14:52:00.318275 | |
| bqg48,"Rapid emulsification of a fuel–water rapid internal mixing injector for emulsion fuel combustion","In this study, a fuel–water rapid internal mixing injector capable of reducing emissions from combustion furnaces operating under high load conditions was developed. Employing this injector allows the injection of a fresh emulsified fuel mixture without requiring surfactants or additional processing equipment. The aim of the present study was to investigate the emulsification, atomization, and emission performance of the injector when using soybean oil as a model high-viscosity fuel from a renewable source. Successful emulsification was observed in the mixing chamber over a wide range of water content ratios up to 0.5, under which a water-in-oil emulsion was discharged from the injector. As the water content ratio was increased, the Sauter mean diameter of the droplets in the spray increased. This is a result of the decrease in the mass flow ratio of atomizing gas to liquid and the increase in the viscosity of the fuel emulsion. Although the emulsification of the base fuel resulted in the discharge of large droplets, the results showed that the nitrogen oxide and particulate matter emissions from a combustion furnace incorporating the injector were found to be reduced simultaneously following the introduction of water even under a high combustion load.",1,https://api.osf.io/v2/files/5c0093a8b7ef140019492e82/,324,https://engrxiv.org/bqg48/,10.31224/osf.io/bqg48,10.1016/j.energy.2018.10.182,2018-11-30T01:46:40.718645,2019-08-30T13:17:32.454330 | |
| bjhwd,"A model for surface tension in the meshless finite volume particle method without spurious velocity","A surface tension model has been developed in the finite volume particle method (FVPM). FVPM is a conservative, consistent, meshless particle method that incorporates properties of both smoothed particle hydrodynamics and the mesh-based finite volume method. Surface tension force is applied only on free-surface particles, which are inexpensively and robustly detected using the FVPM definition of interparticle area, analogous to cell face area in the finite volume method. We present a model in which the direction of the pairwise surface tension force is approximated by the common tangent of free-surface particle supports. The new surface tension model is implemented in 2D. The method is validated for formation of an equilibrium viscous drop from square and elliptical initial states, drops on hydrophobic and hydrophilic walls, droplet collision, and impact of a small cylinder on a liquid surface. Results are practically free from parasitic current associated with inaccurate curvature determination in some methods.",1,https://api.osf.io/v2/files/5c001470aeafc80017882e0a/,373,https://engrxiv.org/bjhwd/,10.31224/osf.io/bjhwd,10.1016/j.compfluid.2018.11.019,2018-11-29T16:35:20.832728,2018-11-29T16:51:35.093230 | |
| by3h4,"Security Issues In A Relay Based Network","This document is about techniques in which the performance and reliability of a wireless network can be improved. We will discuss the cooperative communication system, how it operates and its security issues. Also, the future of the diversity in wireless networks will be analysed. In cooperative networks, the data is transmitted from sender to receiver via intermediate nodes called relays. The main objective is to consider the pros and cons of relaying techniques in order to improve wireless local area networks (WLANs)[1].",1,https://api.osf.io/v2/files/5bfcfe5bf961460018bbc995/,291,https://engrxiv.org/by3h4/,10.31224/osf.io/by3h4,,2018-11-27T08:22:09.863493,2018-11-27T14:48:30.301626 | |
| qpc2f,"A Feasibility Study on Flapping Wing Actuation using Dielectric Elastomers","Introduction of smart materials as actuators in flapping wing micro aerial vehicles (MAVs) eliminates the need for the traditional rotary power delivery mechanisms, allowing for lighter, smaller and more energy efficient designs. General kinematics of insect flight is investigated to relate the independent variable wing length to two dependent variables wingbeat frequency and stroke amplitude, to establish a benchmark of characteristics the smart material must possess. Dielectric Elastomers due to their high actuation strain, high actuation speed, low density, compliant nature and silent operation were evaluated to be suitable for flapping wing actuation. Through an experimental reference design study, corresponding finite element validation and extrapolation of the model to a unimorph bender actuator representative of an insect wing, a path is laid to achieving the kinematic parameters required for flight. Further modelling and analysis of the high voltage custom waveform generator and sensing circuit used in the experiments is done using a SPICE simulator.",1,https://api.osf.io/v2/files/5bfbb8df1a972e0018c5804f/,411,https://engrxiv.org/qpc2f/,10.31224/osf.io/qpc2f,,2018-11-26T09:27:11.045197,2018-11-26T15:03:21.374286 | |
| xwmh8,"Blo-Wiper: A Feasibility Study and Introduction of New Methods to Approach National Car Development Project (A Case Study for Malaysia Small Medium Enterprise-SME)","Malaysia is the only country in South East Asia has local capability to manufacture car from concept until mass production. The manufacturing sector has contributed as the largest Gross Domestic Product (GDP) for Malaysian economy. Thus, the decision of new government elected on 2018 to start a new national car project is the best decision to boost manufacturing sector to the next level. Currently, involvement of Malaysian SMEs in automotive manufacturing sector is still small and this time needs to be improved. Thus, new methods are suggested to help more SMEs to take part in 3rd National Car Project. The Characteristics of Potential High Skilled Automotive Entrepreneur (C-POSITIVE) and Rapid Development of Automotive SMEs (RADAS) will help related government agencies to selected suitable candidates to be Malaysian automotive SMEs. Besides that, the authors have invented Blo-Wiper concept to improve conventional windshield wiper which is ineffective during heavy rain especially for countries located at equatorial climate like Malaysia. The Blo-Wiper concept using two rain droplets removing process; blowing and wiping shown significant result to increase driver visibility based on preliminary simulation study. This white paper is prepared by the authors to help Malaysian government in 3rd National Car Project.",1,https://api.osf.io/v2/files/5bfb98d52885c4001b112509/,296,https://engrxiv.org/xwmh8/,10.31224/osf.io/xwmh8,,2018-11-26T07:10:11.134556,2018-11-29T16:18:40.367959 | |
| ju6rv,"Preliminary System and Hardware Design for Guardian, a Low-cost Automatic Pill Dispenser with Pneumatic Technology","This paper presents on-going progress on Guardian, a low-cost automatic pill dispenser aimed to help the elderly community to take their medication on time. The device is composed of a cylindrical body with a pneumatically powered system and rotating robotic arm in the center column as its core technology. This information in the paper is meant to record the development process that led to the filing of a provisional patent USPTO 15964875 (Application Number).",1,https://api.osf.io/v2/files/5bfa58637a55470016730c0c/,310,https://engrxiv.org/ju6rv/,10.31224/osf.io/ju6rv,,2018-11-25T08:10:10.454160,2018-11-25T16:01:04.507702 | |
| rv2tz,"Extensions of the meshless Finite Volume Particle Method (FVPM) for static and dynamic free-surface flows","The Finite Volume Particle Method (FVPM) is a meshless method that incorporates features of both Smoothed Particle Hydrodynamics and the Finite Volume Method. Here, two new formulations are presented which enhance its performance in simulation of free surface flows. One is a method for determining the velocity of the free surface, making use of a partial Riemann problem to analyse the flow between the particle barycentre and the geometric free surface. The second is a well-balanced formulation for gravity forces that enables hydrostatic equilibrium to be preserved exactly. Results are presented for hydrostatic, 1D impact, dambreak and deep-water standing wave test cases. Computations display convergence and good agreement with experimental data. The new methods recover exact hydrostatic equilibrium, improve robustness and reduce acoustic pressure fluctuations in dambreak flows, and reduce dissipation.",1,https://api.osf.io/v2/files/5bf6a0e2c21cd8001ba131f7/,446,https://engrxiv.org/rv2tz/,10.31224/osf.io/rv2tz,10.1016/j.compfluid.2018.09.019,2018-11-22T12:34:03.435526,2018-11-22T14:55:19.598184 | |
| 2pzrv,"Comparison of Replica Leaf Surface Materials for Phyllosphere Microbiology","Artificial surfaces are routinely used instead of leaves to enable a reductionist approach in phyllosphere microbiology, the study of microorganisms residing on plant leaf surfaces. For instance, flat surfaces such as nutrient agar, enable the influence of nutrient supply on microorganisms to be investigated. In contrast microstructured surfaces, such as isolated leaf cuticles or reconstituted leaf waxes enable the influence of physicochemical properties to be investigated. However, interest in replica leaf surfaces as an artificial surface is growing. As replica surfaces offer an improved representation of the complex topography of leaf surfaces. The use of replica leaf surfaces has to date primarily been focused on replicating the superhydrophobic surfaces of leaves. Whereas in this paper, we investigate potential replica surface materials for phyllosphere microbiology studies. Using a test pattern, we investigated the resolution, the degradation characteristics in environmental conditions, surface energy, and bacterial survival characteristics for each potential replica material. Our results indicate that PDMS is the most suitable material for producing replica leaf surfaces. Due to the high resolution achieved through replica molding, extended stability, hydrophobic properties, and bacterial survival characteristics comparable to isolated leaf cuticles. Our experiments highlight the importance of considering the inherent material properties, when selecting a replica leaf surface for phyllosphere microbiology studies. A replica leaf produced in PDMS offers a control surface that can be used for investigating microbe-microbe and microbe-plant interactions in the phyllosphere. Thus, in turn enabling mitigation strategies against pathogens to either the plant host or humans to be developed.",1,https://api.osf.io/v2/files/5bee197b6989d00018497f9d/,357,https://engrxiv.org/2pzrv/,10.31224/osf.io/2pzrv,10.1371/journal.pone.0218102,2018-11-16T02:14:13.426372,2019-07-14T00:42:37.324004 | |
| ne8fv,"Investigation of the Effect of Electrode Surface Roughness on Spark Ignition","Lean-burn engines are important due to their ability to reduce emissions, increase fuel efficiency, and mitigate engine knock. In this study, the surface roughness of spark plug electrodes is investigated as a potential avenue to extend the lean flammability limit of natural gas. A nano-/micro-morphology modification is applied on surface of the spark plug electrode to increase its surface roughness. High-speed Z-type Schlieren visualization is used to investigate the effect of the electrode surface roughness on the spark ignition process in a premixed methane-air charge at different lean equivalence ratios. In order to observe the onset of ignition and flame kernel behavior, experiments were conducted in an optically accessible constant volume combustion chamber at ambient pressures and temperatures. The results indicate that the lean flammability limit of spark-ignited methane can be lowered by modulating the surface roughness of the spark plug electrode.",1,https://api.osf.io/v2/files/5bede89f6989d00017495cd1/,458,https://engrxiv.org/ne8fv/,10.31224/osf.io/ne8fv,10.1115/ICEF2018-9691,2018-11-15T21:46:23.999998,2018-11-16T14:18:41.076103 | |
| da7gf,"A Computational Investigation of Non-Premixed Combustion of Natural Gas Injected into Mixture of Argon and Oxygen","Natural gas is traditionally considered as a promising fuel in comparison to gasoline due to the potential of lower emissions and significant domestic reserves. These emissions can be further diminished by using noble gases, such as argon, instead of nitrogen as the working fluid in internal combustion engines. Furthermore, the use of argon as the working fluid can increase the thermodynamic efficiency due to its higher specific heat ratio. In comparison to pre-mixed operation, the direct injection of natural gas enables the engine to reach higher compression ratios while avoiding knock. Using argon as the working fluid increases the in-cylinder temperature at top dead center and enables the compression ignition of natural gas. In this numerical study, the combustion quality and ignition behavior of methane injected into a mixture of oxygen and argon has been investigated using a three-dimensional transient model of a constant volume combustion chamber. A dynamic structure large eddy simulation model has been utilized to capture the behavior of the non-premixed turbulent gaseous jet. A reduced mechanism consists of 22-species and 104-reactions were coupled with the CFD solver. The simulation results show that the methane jet ignites at engine-relevant conditions when nitrogen is replaced by argon as the working fluid. Ignition delay times are compared across a variety of operating conditions to show how mixing affects jet development and flame characteristics.",1,https://api.osf.io/v2/files/5bede6ec4b37e100194ca0de/,431,https://engrxiv.org/da7gf/,10.31224/osf.io/da7gf,10.1115/ICEF2018-9618,2018-11-15T21:39:30.668652,2018-11-16T14:17:49.361869 | |
| j94a8,"Numerical Modelling of Seabed Impact Effects on Chain and Small Diameter Mooring Cables","Catenary mooring lines experience liftoff from and grounding on the seabed when undergoing large dynamic motions. Numerical line mooring models account for this interaction using various seabed models and it is known that the action of liftoff and grounding may lead to large dynamic tension fluctuations. These fluctuations may be spurious due to the inability of discretised mooring models to adequately account for the effect of the seabed on the mooring line. In this work, the root cause and conditions that lead to the production of the large dynamic tension fluctuations is determined. The effect of line discretisation and seabed model on the tension | |
| fluctuations is investigated using the widely used spring-mattress approach and a modified seabed reaction force model. An in-house mooring code was developed to perform these investigations. For code validation and benchmarking, and to illustrate the existence of the tension fluctuations problem due to nodal grounding in | |
| existing mooring line simulation codes, comparisons are made to a commercial software.",1,https://api.osf.io/v2/files/5bebb5c29ebb7b0018bebe5c/,370,https://engrxiv.org/j94a8/,10.31224/osf.io/j94a8,10.1016/j.apor.2018.09.010,2018-11-14T05:50:34.225383,2018-11-14T14:37:16.170431 | |
| vng79,"Fabrication of Multi-material 3D Structures by the Integration of Direct Laser Writing and MEMS Stencil Patterning","The construction of a complex, 3D optical metamaterial challenges conventional nanofabrication techniques. These metamaterials require patterning of both a deformable mechanical substrate and an optically-active structure with ~200 nm resolution and precision. The soft nature of the deformable mechanical materials often precludes the use of resist-based techniques for patterning. Furthermore, FIB deposition approaches produce metallic structures with considerable disorder and impurities, impairing their optical response. In this paper we discuss a novel solution to this nanofabrication challenge -- the integration of direct laser writing and MEMS stencil patterning. We demonstrate a variety of methods that enable this integration and then show how one can produce optically-active, 3D metamaterials. We present optical characterization data on one of these metamaterials to demonstrate the viability of our nanofabrication approach.",1,https://api.osf.io/v2/files/5be9e6ec319ea5001e4a200e/,294,https://engrxiv.org/vng79/,10.31224/osf.io/vng79,,2018-11-12T21:08:14.416001,2018-11-12T21:11:27.710343 | |
| ntfdp,"Using Drive-by Health Monitoring to Detect Bridge Damage Considering Environmental and Operational Effects","Drive-by Health Monitoring utilizes accelerometers mounted on vehicles to gather dynamic response data that can be used to continuously evaluate the health of bridges faster and with less equipment than traditional structural health monitoring practices. Because vehicles and bridges create a coupled system, vehicle acceleration data contains information about bridge frequencies that can be used as health indicators. However, for drive-by health monitoring to be viable, variabilities in dynamic measurements caused by environmental and operational parameters, such as temperature, vehicle speed, traffic, and surface roughness need to be considered. In this paper, a finite element model of a simply supported bridge is developed considering the aforementioned variabilities and various levels of structural damage. Vehicle acceleration data obtained from the model is analyzed in the frequency domain and processed using a neural network architecture. This method is used to determine the relationships between noise inducing variables and changes in vehicle dynamic response spectrum; these relationships are leveraged to predict the overall health of the subject bridge. The results from this study indicate that the proposed approach can serve as a viable health monitoring strategy and should be further tested on physical bridge systems.",1,https://api.osf.io/v2/files/5be9b78dd354e900177d0802/,327,https://engrxiv.org/ntfdp/,10.31224/osf.io/ntfdp,,2018-11-12T17:30:55.981954,2019-07-19T20:42:31.043644 | |
| ejy4v,"LITHIUM DOPED DOUBLE WALLED CARBON NANO-TUBE ELECTRICITY STORAGE CELL","Many double walled carbon nano-tubes, the inner one intercalated with lithium atoms, can be used to construct an electricity storage cell of high capacity, easy to charge, and easy to use. Ideal for motor vehicles and multiple other uses.",1,https://api.osf.io/v2/files/5be8e50758c0de0017741840/,248,https://engrxiv.org/ejy4v/,10.31224/osf.io/ejy4v,,2018-11-12T02:41:22.915019,2018-11-12T04:34:38.839523 | |
| s5j7u,"Influence of insulation defects on the thermal performance of walls. An experimental and numerical investigation","The addition of insulating layers on vertical walls of buildings is a common practice for providing a higher thermal insulation of the envelope. Workmanship defects, however, might influence the effectiveness of such insulation strategy. Damaged materials, incorrect installation, use of aged or weathered materials might alter the capability of reducing heat transfer through the envelope, whether vertical or sloped. In this work, drawbacks caused by the wrong installation of insulating material and by damaged material are assessed. A specimen wall was investigated by experimental and numerical approaches, the latter carried out by using COMSOL Multiphysics®. Results are compared and discussed.",1,https://api.osf.io/v2/files/5be7652958c0de00167179fb/,330,https://engrxiv.org/s5j7u/,10.31224/osf.io/s5j7u,10.1016/j.jobe.2018.10.029,2018-11-10T23:21:49.413982,2018-11-11T13:13:54.587626 | |
| 9gf82,"The impact of climatic extreme events on the feasibility of fully renewable power systems: a case study for Sweden","Future energy systems with high shares of intermittent renewables will be stressed by climatic extreme events. We assess the frequency, duration, and magnitude of such extreme residual load events with a share of VRE generation of about 50% for the case of Sweden. For our analysis, we use 29 years of river runoff and of wind power and PV generation simulated from physical models. Hourly load is simulated from temperature data with a time series model. The resulting time series are combined with historic capacity and ramping restrictions of hydro and thermal power plants in an optimization model to minimize extreme residual load events. Results indicate that under high VRE shares climatic extreme events affect even highly flexible power systems as the Swedish one. Replacing current nuclear power capacities by wind power results on average in three extreme residual load events per year. These events are partly linked to the observation that wind speeds are likely below seasonal average in very cold weather conditions. Deploying PV generation capacities instead of wind increases the number of extreme residual load events by about 6 %, as most events occur during the winter month when solar generation is close to zero.",1,https://api.osf.io/v2/files/5be440610fa9f5001cb46995/,299,https://engrxiv.org/9gf82/,10.31224/osf.io/9gf82,,2018-11-08T14:02:21.846012,2019-04-25T20:56:55.960353 | |
| rfmd5,"On the Convergence of the Matrix Lambert W Approach to Solution of Systems of Delay Differential Equations","Convergence aspects of the matrix Lambert W function method for solving systems of delay differential equations (DDEs) are considered. Recent research results show that convergence problems can occur with certain DDEs when using the well-established Q-iteration approach. A complementary, and recently proposed, W-iteration approach is shown to converge even on systems where the Q-iteration fails. Furthermore, the role played by the branch numbers k = -∞ .. -2, -1, 0, 1, 2 , .. ∞ of the matrix Lambert W function, Wk, in terms of initializing the iterative solutions, is also discussed and elucidated. Several second order examples, known to have convergence problems with Q-iteration, are readily solved by W-iteration. Examples of third and fourth order DDEs show that the W-iteration method is also effective on higher-order systems.",1,https://api.osf.io/v2/files/5be3452e0fa9f5001bb338b0/,374,https://engrxiv.org/rfmd5/,10.31224/osf.io/rfmd5,,2018-11-07T20:08:45.138861,2018-11-07T20:11:32.052784 | |
| gw4ts,"Diversity In Wireless Networks","This document is about techniques in which the performance and reliability of a wireless network can be improved. We will discuss the cooperative communication system, how it operates and its security issues. Also, the future of the diversity in wireless networks will be analysed [1]. In cooperative networks, the data is transmitted from sender to receiver via intermediate nodes called relays. The main objective is to consider the pros and cons of relaying techniques in order to improve wireless local area networks (WLANs) [2].",1,https://api.osf.io/v2/files/5be31d7ae057c600160dd790/,297,https://engrxiv.org/gw4ts/,10.31224/osf.io/gw4ts,,2018-11-07T17:16:23.915509,2018-11-07T19:41:21.666609 | |
| vy3na,"A Power-Domain NOMA Inspired Overlay Spectrum Sharing Scheme","Non-orthogonal multiple access (NOMA) and cooperative spectrum sharing (CSS) are integrated into this work to enhance both spectrum efficiency and utilization. An overlay spectrum sharing is proposed by exploiting NOMA in coordinated direct and relay transmission (CDRT) (termed as CSS-NOMA-CDRT). In CSS-NOMA-CDRT, a primary strong NOMA user is directly served by primary transmitter (PT), whereas a primary NOMA weak user needs the assistance of a relay to communicate with PT. Instead of using a dedicated relay, a secondary transmitter (ST) acts as a relay to forward the primary symbol to NOMA weak user and ST transmits own symbol to its receiver at the same time. The performance of the proposed CSS-NOMA-CDRT is evaluated along with closed-form solutions, in terms of ergodic sum capacity and outage probability. Through the analytical and Monte Carlo simulation results, it is demonstrated that CSS-NOMA-CDRT can obtain remarkable capacity gain as compared to the conventional NOMA-based CDRT.",1,https://api.osf.io/v2/files/5be1c08846f8cd0018d42363/,365,https://engrxiv.org/vy3na/,10.31224/osf.io/vy3na,,2018-11-06T16:31:08.260134,2018-11-06T17:39:46.038213 | |
| xvbry,"Continuum Arm Manipulator Refinement for Assistive Technology","Rigid link robots currently dominate the market for manipulators in assistive technology, though research on continuum robots for assistive technology has been developing over recent years. These types of robots have a continuous backbone that allows them to have infinite degrees of freedom, making them highly compliant, however this brings challenges in terms of modelling and control. In this work, we describe the design for a continuum arm suitable for assistive technology applications.",1,https://api.osf.io/v2/files/5be0bf28a613300016cc4bae/,303,https://engrxiv.org/xvbry/,10.31224/osf.io/xvbry,,2018-11-05T22:08:58.355653,2019-01-07T14:11:59.111226 | |
| 5dtz2,"Pneumatic Braking Mechanism","Pneumatic Braking Mechanism is an implementation of regenerative braking system for automobiles. It uses pneumatic compression to store the kinetic energy of the vehicle. The compressed air is used to produce electricity through a turbine, and then used for supercharging the engine of the automobile. | |
| The complete mechanism can be divided into two parts: | |
| - Braking | |
| - Regeneration | |
| Regeneration mechanism can be further subdivided into: | |
| - Expansion | |
| - Supercharging | |
| The rotational motion of wheels of the vehicle is used to drive reciprocating compressors. Compressors are engaged with the help of a clutch and crankshaft unit when brakes are applied. Compression process converts the kinetic energy of the vehicle in the form of compressed air. In the process, vehicle loses its energy and comes to a standstill. | |
| The compressed air goes to a turbine and generator unit where expansion takes place and electricity is produced. The outlet air from turbine at lower pressure is used for supercharging.",1,https://api.osf.io/v2/files/5bdcc112954c620017e4c234/,295,https://engrxiv.org/5dtz2/,10.31224/osf.io/5dtz2,,2018-11-02T21:43:24.646367,2018-11-02T22:01:30.390043 | |
| n7h9y,"Open Loop Position Control of Soft Continuum Arm Using Deep Reinforcement Learning","Soft robots undergo large nonlinear spatial deformations due to both inherent actuation and external loading. The physics underlying these deformations is complex, and often requires intricate analytical and numerical models. The complexity of these models may render traditional model based control difficult and unsuitable. Model-free methods offer an alternative for analyzing the behavior of such complex systems without the need for elaborate modeling techniques. | |
| In this paper, we present a model-free approach for open loop position control of a soft spatial continuum arm, based on deep reinforcement learning. The continuum arm is pneumatically actuated and attains a spatial workspace by a combination of | |
| unidirectional bending and bidirectional torsional deformation. We use Deep-Q Learning with experience replay to train the system in simulation. The efficacy and robustness of the control policy obtained from the system is validated both in simulation and on the continuum arm prototype for varying external loading conditions",1,https://api.osf.io/v2/files/5bdb1745a28e68001ba32d45/,737,https://engrxiv.org/n7h9y/,10.31224/osf.io/n7h9y,,2018-11-01T15:14:22.130682,2018-11-06T14:49:08.893270 | |
| ze6yu,"FACE DETECTION AND RESTORATION UNDER OCCLUSIONS : A LITERATURE REVIEW","One of the main challenges of the face recognition is occlusions. Occlusion in an image refers to hindrance in the view of an object. Face recognition which work in the presence of occlusions are core for the current needs in the field of identification of suspects, as criminals try to take advantage of the weaknesses among the implemented security systems by camouflaging themselves and occluding their face with eyeglasses, hair, hands, or covering their face with scarves and hats. Human face recognition under occlusion is broadly classified into 8 categories Karhunen-Loeve Expansion Method, Model Based Method, Correlation Based Method, Template Based Method, Feature Based Method, Geometric Based Method, Singular Value Decomposition Based Method and Neural Network Based Algorithm. The paper details the experiments and databases used to handle the problem of occlusion and the results obtained by different authors. Lastly, a comparison of various techniques is presented and some conclusions are drawn referring to the best outcomes.",1,https://api.osf.io/v2/files/5bda8acf9764d2001a57b905/,190,https://engrxiv.org/ze6yu/,10.31224/osf.io/ze6yu,,2018-11-01T05:13:15.265158,2018-11-01T14:11:02.242303 | |
| eg3qk,"Technical Report for the Erratum of:\\ ""Design and Evaluation of a Balance Assistance Control Moment Gyroscope"" [ASME J. Mech. Rob., 2017, 9(5), p.051007: DOI: 10.1115/1.4037255]","Details for the errata of the paper ""Design and Evaluation of a Balance Assistance Control Moment Gyroscope"" DOI: 10.1115/1.4037255, published in the ASME Journal of Mechanisms and Robotics.",1,https://api.osf.io/v2/files/5bd873a3e6ea9400193421f4/,340,https://engrxiv.org/eg3qk/,10.31224/osf.io/eg3qk,,2018-10-30T15:11:15.690764,2018-10-30T16:37:49.925410 | |
| 298d4,"Integrated energy analysis of cutting process and spindle subsystem in a turning machine","This paper presents a novel approach for systematic energy efficiency evaluation and optimization in turning operations, combining spindle, chiller and material removal models. Framing a joint machine-process design approach, the proposed study aims at selecting optimal combinations of cutting parameters (feed rate, depth of cut and spindle speed) for a given spindle-chiller assembly, able to minimize the energy consumption. Contrary to most of the literature, where the efficiency analysis is fully empirical, relying on extended cutting test campaigns, here a model-based approach is adopted. The goal is to characterize a key subsystem of modern machine tools, often used in both turning and milling machines, composed by a permanent magnet brushless direct-drive spindle with a dedicated chiller unit. Analytical relationships are identified, producing efficiency maps as a function of various process parameters. Physic-based models are exploited, reproducing electrical and mechanical energy dissipation occurring in the spindle and chiller units and in the material removal process. The models parameters are identified by a reduced set of spindle ramp-up and cutting tests, executed in an industrial context. Then, an overall process efficiency optimization is performed and discussed.",1,https://api.osf.io/v2/files/5bd1b149cce43e0016790434/,370,https://engrxiv.org/298d4/,10.31224/osf.io/298d4,10.1016/j.jclepro.2017.09.234,2018-10-25T12:09:45.033536,2018-10-25T14:28:34.913028 | |
| q6h8e,"Cooperation for Vehicular Delay Tolerant Network","This article reviews the literature related to Vehicular Delay Tolerant Network with focus on Cooperation. It starts by examining definitions of some of the fields of research in VDTN. An overview of VDTN with cooperative networks is presented.",1,https://api.osf.io/v2/files/5bd19db8cce43e001877e41e/,260,https://engrxiv.org/q6h8e/,10.31224/osf.io/q6h8e,,2018-10-25T10:41:58.455981,2018-10-25T14:27:06.423567 | |
| bgzd3,"Relaying in Telecommunications","In recent years, Vehicular Ad Hoc Network (VANET) has attracted considerable attention both from academia and industry. In VANET, multiple access technologies such as cellular system, Wireless Local Area Network (WLAN) are integrated to support the service requirements of vehicular users. Multi-hopping vehicular networks (VANETs) provide environmental awareness across large regions even if there does not exist direct communication between several vehicles within the region. However, the volume of messages that are received and rebroadcasted via the relay vehicles can cause broadcast storms and network jams. In them the systems are subject to wireless interference and disconnections, thus hindering the availability and reliability of source-destination connections. Another major problem arises when VANETs are sparse, causing excessive retransmissions and delays due to long periods without maintain connection between pair of vehicles. This article reviews the literature related to Vehicular Delay Tolerant Network with focus on Cooperation. It starts by examining definitions of some of the fields of research in VDTN. An overview of VDTN with cooperative networks is presented.",1,https://api.osf.io/v2/files/5bd16eda8b330000181fa73e/,307,https://engrxiv.org/bgzd3/,10.31224/osf.io/bgzd3,,2018-10-25T07:22:47.522861,2018-10-25T14:24:40.882182 | |
| smdax,"Denial of Service Attack in Cooperative Networks","In Denial of Service (DoS) attack the network resources are either delayed or refused to be assigned to the requested | |
| user [1]. This may occurs due to verity of reasons, could be intentionally or unintentionally. The unintentional case is quite hard | |
| to mitigate. In this paper we will refer the former case in context of cooperative networks. In cooperative networks we relay the | |
| data via intermediate nodes called relays. The relay selection is mechanism [2] need to be devised with focus on mitigating | |
| such attacks. In this paper we will enhance the relay selection mechanism address by [3] to propose the novel relay selection | |
| with emphasis on security of Wireless Local Area Networks.",1,https://api.osf.io/v2/files/5bcc66b4e121f20018fe550f/,251,https://engrxiv.org/smdax/,10.31224/osf.io/smdax,,2018-10-21T11:53:10.507355,2018-10-21T15:37:59.284610 | |
| 3tsgr,"Technical Note: Nominal Stiffness Evaluation and Regression Analysis of GT-2 Rubber-Fiberglass Timing Belts","GT-style rubber-fiberglass (RF) timing belts are designed to effectively transfer rotational motion from pulleys to linear motion in small machines and mechatronic systems. One of the characteristics of belts under this type of loading condition is that the length between load and pulleys changes during operation, thereby changing their effective stiffness. It has been shown that the effective stiffness of such a belt is a function of a ""nominal stiffness"" and the real-time belt section lengths. However, this nominal stiffness is not necessarily constant; it is common to assume linear proportional stiffness, but this often results in system modeling error. This technical note describes a brief study where the nominal stiffness of two lengths (400 mm and 760 mm ) of GT-2 RF timing belts was tested up to breaking point; regression analysis was performed on the results to best model the observed stiffness. The study was replicated three times, providing a total of six stiffness curves. It was found that cubic regression models (R^2 > 0.999) were the best fit, but that quadratic and linear models still provided acceptable representations of the whole dataset with R^2 values above 0.940.",1,https://api.osf.io/v2/files/5bcae418a334dd0017f0d155/,387,https://engrxiv.org/3tsgr/,10.31224/osf.io/3tsgr,,2018-10-20T08:29:13.646212,2018-10-21T03:27:28.317734 | |
| 7vkun,"Numerical Modelling of Structural Behaviour of Continuously Reinforced Concrete Pavement","Continuously reinforced concrete pavement (CRCP) rapidly becomes a common standard in most highway pavement design due to its high performance. Early-age cracks play a crucial role in characterising CRCP's long-term performance, hence crack formations and patterns are of interest in most highway departments. The design parameters of a CRCP are studied in this work as a parametric study on efficient design configuration. Numerical experiments were performed to produce a stress profile induced by crack initiation and long-term traffic load. This work contributes a probabilistic study on crack pattern formation from typical stress profile, including environmental and shrinkage stress, as an insight into predicting the likelihood of crack patterns initiation and propagation along the depth of the concrete slab. Studies also showed transverse steel bar plays a crucial role in determining the location of the crack formation, but a minimal effect in controlling crack width and deflection. A study on the probabilistic model helps pavement design to produce a desirable crack pattern, to perform controlled-cracks that enhance the vertical load transferability of a cracked CRCP.",1,https://api.osf.io/v2/files/5bc7ab6c11fd9d001793d7a8/,4737,https://engrxiv.org/7vkun/,10.31224/osf.io/7vkun,,2018-10-17T21:45:01.342512,2018-10-26T20:03:07.331780 | |
| cn4j6,"Electrospun Polyethene oxide-graphite composite anode for solid-state lithium-ion batteries","Current lithium-ion batteries are close to reaching their physicochemical energy density limit. Moreover, they present high operation risks regarding their liquid electrolyte. Solid-state batteries are a promising alternative to overcome these problems. They offer safe operation, and potentially improved energy and power density. The option of operating at higher voltages has led to the possibility of employing high capacity electrodes. In this study, the synthesis of a nanostructured anode through electrospinning was carried out. This electrode is based on polymer nanofibres with intercalated graphite particles. The effect of molecular weight, voltage, temperature and humidity has been studied for the formation of smooth and uniform nanofibres. At the optimized conditions, Polyethylene oxide (PEO)-Polyethylene glycol (PEG) nanofibres with diameters around 600 nm were successfully electrospun. The effect of graphite loading on the electrospinning of this solution was also studied. A 30% graphite particle loading in the final fibres was reached with a reproducible methodology. It was found that the electrospun graphite particles received a polymer coating during electrospinning. EDX analysis confirmed that most of the graphite particles are covered by a polymer layer, confirming this hypothesis. Even if it is unclear how this affects the behaviour of the graphite for energy storage, high graphite content was electrospun together with PEO nanofibres with a new methodology.",1,https://api.osf.io/v2/files/5bc4eadadd43d20019c075a4/,221,https://engrxiv.org/cn4j6/,10.31224/osf.io/cn4j6,,2018-10-15T19:41:44.444581,2018-10-15T19:46:25.764869 | |
| xs64k,"Needleless electrospinning of PVP/PGS fibrous scaffolds for skin tissue engineering applications","Scaffolds and implants used for tissue engineering need to be adapted for their mechanical properties with respect to their environment within the human body. Therefore, a novel composite for skin tissue engineering is presented by use of blends of Poly(vinylpyrrolidone) (PVP) and Poly(glycerol sebacate) (PGS) were fabricated via the needleless electrospinning technique. The formed PGS/PVP blends were morphologically, thermochemically and mechanically characterized. The morphology of the developed fibers related to the concentration of PGS, with high concentrations of PGS merging the fibers together plasticizing the scaffold. The tensile modulus appeared to be affected by the concentration of PGS within the blends, with an apparent decrease in the elastic modulus of the electrospun mats and an exponential increase of the elongation at break. Ultraviolet (UV) crosslinking of PGS/PVP significantly decreased and stabilized the wettability of the formed fiber mats, as indicated by contact angle measurements. In vitro examination showed good viability and proliferation of human dermal fibroblasts over the period of a week. The present findings provide important insights for tuning the elastic properties of electrospun material by incorporating this unique elastomer, as a promising future candidate for skin substitute constructs.",1,https://api.osf.io/v2/files/5bc4dda72aa873001cc5a1b9/,306,https://engrxiv.org/xs64k/,10.31224/osf.io/xs64k,,2018-10-15T18:40:57.384565,2018-10-15T19:04:59.403424 | |
| 9hqs7,"Exploring the Economic, Environmental, and Travel Implications of Changes in Parking Choices due to Driverless Vehicles: An Agent-Based Simulation Approach","Fully driverless automated vehicles (AVs) could considerably alter the proximity value of parking, due to an AV’s ability to drop passengers off at their destination, search for cheaper parking, and return to pick up their occupants when needed. This study estimates the potential impact of privately-owned driverless vehicles on vehicle miles traveled (VMT), energy use, emissions, parking revenue, and daily parking cost savings in the city of Seattle, Washington from changes in parking decisions using an agent-based simulation model. Each AV is assumed to consider the cost to drive to each parking spot, the associated daily parking cost, and the parking availability at each location, and the AV ranks each choice in terms of economic cost. The simulation results indicate at the low penetration rates (5 to 25 percent AV penetration) AVs in downtown Seattle would travel an additional 3.5- 4.0 miles per day on average, and high penetration rates (50 to 100 percent AV penetration) would travel an additional 5.6-8.4 miles per day on average. The results also suggest that as AV penetration rates increase, parking lot revenues decrease significantly and could likely decline to the point where operating a lot is unsustainable economically, if no parking demand management policies are implemented. This could lead to changes in land use as the amount of parking needed in urban areas is reduced and cars move away from the downtown area for cheaper parking. This analysis provides an illustration of the first-order effects of AVs on the built environment and could help inform near and long- term policy and infrastructure decisions during the transition to automation.",1,https://api.osf.io/v2/files/5bc416f1512c03001990c995/,557,https://engrxiv.org/9hqs7/,10.31224/osf.io/9hqs7,10.1061/(ASCE)UP.1943-5444.0000488,2018-10-15T04:45:18.625763,2018-10-15T13:49:55.934825 | |
| 9uzbh,"Frequency and Time Domain Analysis of sRNA-based Treatment for Inflammatory Bowel Disease","The validity of a complex reaction pathway pro- posed to treat Inflammatory Bowel Disease (IBD) was verified by a comprehensive time and frequency domain analysis. The model was taken to the frequency domain to study the effect and the significance of the negative feedback loop introduced by the reaction pathways. It could be shown that such proposed probiotics have very interesting potentials that could be used extensively in near future.",1,https://api.osf.io/v2/files/5bc337cd512c030018900410/,374,https://engrxiv.org/9uzbh/,10.31224/osf.io/9uzbh,,2018-10-14T12:46:09.939542,2018-10-15T20:50:41.295019 | |
| rg8pn,"A Novel Harmonic Current Control Algorithm","This paper presents a novel control algorithm for | |
| high-torque low-speed permanent magnet synchronous motors | |
| for direct drive applications. A new induced voltage based | |
| formulation of the electromagnetic torque is developed and a | |
| novel current control algorithm is designed to reduce the torque | |
| ripples which are originated from the flux harmonics. A | |
| prototype motor with relatively high induced voltage harmonics | |
| is designed and constructed and the experiment results of the | |
| Harmonic control algorithm are compared to the results of a | |
| conventional Field Oriented Control.",1,https://api.osf.io/v2/files/5bbf08e695e98a001a781612/,835,https://engrxiv.org/rg8pn/,10.31224/osf.io/rg8pn,,2018-10-11T08:25:43.351856,2018-10-11T13:35:16.229378 | |
| j7kf3,"Characterization of a Large Electrical Machine Test","The acceptability and also the acceleration of | |
| renewable energy technologies is tightly linked with a better | |
| understanding of dynamic behavior of drive train components | |
| and their interactions. This ultimate understanding of system | |
| characteristics can only be achieved with comprehensive | |
| experimental investigations on different phenomena of large | |
| electrical generators. This leads consequently to a better | |
| verification of numerical and analytical models of large | |
| generators. The large generator-converter lab which is discussed | |
| in this paper is a unique opportunity for deep experimental | |
| investigations on large hydro and wind generators. It is designed | |
| to deal with the current as well as future research topics in the | |
| field of wind and hydro generators and their interactions with | |
| power electronic devices and electrical grid.",1,https://api.osf.io/v2/files/5bbf089895e98a0019783055/,574,https://engrxiv.org/j7kf3/,10.31224/osf.io/j7kf3,,2018-10-11T08:24:25.651458,2018-10-11T13:34:49.981422 | |
| ru6yz,"Design Optimization of Permanent Magnet","A multilevel ant algorithm is developed to optimize the | |
| design process of a surface mounted permanent magnet | |
| synchronous motor. The motor properties are calculated using an | |
| exact magnetic equivalent circuit based analytical model. This | |
| model takes into account the iron saturation, the slot stray fluxes | |
| and the spatial harmonics of rotor and stator fluxes. The | |
| effectiveness of the proposed analytical model is verified in | |
| comparison with measurement of a handmade prototype. Based | |
| on this analytical model the air gap flux density, torque and | |
| induced voltage of the prototype motor are predicted. For an | |
| effective selection of motor parameters, a multipurpose | |
| optimization algorithm is developed, which is based on the | |
| distributed multilevel ant-stigmergy algorithm. The analytical | |
| model together with the optimization algorithm represents a very | |
| effective tool for design of permanent magnet synchronous motor | |
| without any need for time consuming finite element programs.",1,https://api.osf.io/v2/files/5bbf07b83ab4f80019c2e778/,574,https://engrxiv.org/ru6yz/,10.31224/osf.io/ru6yz,,2018-10-11T08:22:29.068967,2018-10-11T13:34:00.133369 | |
| hw3xa,"Virtual Mechanical Testing from Low-Dose CT Scans Predicts Tibial Fracture Time to Union and Outperforms Subjective Outcomes Scoring","Background: Quantitative outcomes assessment remains a persistent challenge in orthopaedic trauma. Although patient-reported outcomes measures (PROMs) and radiographic assessments such as RUST scores are frequently used, very little evidence has been presented to support their validity for measuring structural bone formation or biomechanical integrity. | |
| Methods: A sequential cohort of tibial shaft fracture patients was prospectively recruited for observation following standard reamed intramedullary nailing in a Level I trauma center. Follow-ups at 6, 12, 18, and 24 weeks included X-rays and completion of PROMs (EQ-5D and pain scores). Low-dose computed-tomography (CT) scans were also completed at 12 weeks. Scans were reconstructed in 3D and subjected to virtual mechanical testing via the finite element method to assess fracture limb torsional rigidity relative to intact bone. | |
| Results: Patients reported progressive longitudinal improvement in mobility, self-care, activity, and health over time, but the PROMs were not correlated with structural bone healing. RUST scoring showed moderate intra-rater agreement (ICC = 0.727), but the scores at 12 weeks were not correlated with time to union (R2 = 0.103, p = 0.193) and were only moderately correlated with callus structural integrity (R2 = 0.346, p = 0.010). In contrast, patient-specific virtual torsional rigidity (VTR) was significantly correlated with time to union (R2 = 0.383, p = 0.005) and clearly differentiated one case of delayed union (VTR = 10%, union at 8 months) from the rest of the normally healing cohort (VTR > 60%, median union time 19 weeks) using CT data alone. | |
| Conclusions: PROMs provide insight into the natural history of the patient experience after tibial fracture, but have limited utility as a measure of structural bone healing. RUST scoring, although repeatable, is not a valid longitudinal predictor of time to union. In contrast, virtual mechanical testing from low-dose CT scans provides a quantitative and objective structural callus assessment that reliably predicts time to union and may enable early diagnosis of compromised healing. | |
| Level of Evidence: Diagnostic Level II.",1,https://api.osf.io/v2/files/5bbcff7ccbf33d0017b4805c/,272,https://engrxiv.org/hw3xa/,10.31224/osf.io/hw3xa,,2018-10-09T19:28:45.492090,2018-10-09T20:08:51.720870 | |
| 7c8kz,"Virtual Structural Analysis of Tibial Fracture Healing from Low-Dose Clinical CT Scans","Quantitative assessment of bone fracture healing remains a significant challenge in orthopaedic trauma research. Accordingly, we developed a new technique for assessing bone healing using virtual mechano-structural analysis of computed tomography (CT) scans. CT scans from 19 fractured human tibiae at 12 weeks after surgery were segmented and prepared for finite element analysis (FEA). Boundary conditions were applied to the models to simulate a torsion test that is commonly used to access the structural integrity of long bones in animal models of fracture healing. The output of each model was the virtual torsional rigidity (VTR) of the healing zone, normalized to the torsional rigidity of each patient’s virtually reconstructed tibia. This provided a structural measure to track the percentage of healing each patient had undergone. Callus morphometric measurements were also collected from the CT scans. Results showed that at 12 weeks post-op, more than 75% of patients achieved a normalized VTR (torsional rigidity relative to uninjured bone) of 85% or above. The predicted intact torsional rigidities compared well with published cadaveric data. Across all patients, callus volume and density were weakly and non-significantly correlated with normalized VTR and time to clinical union. Conversely, normalized VTR was significantly correlated with time to union (R2 = 0.383, p = 0.005). This suggests that fracture scoring methods based on the visual appearance of callus may not accurately predict mechanical integrity. The image-based structural analysis presented here may be a useful technique for assessment of bone healing in orthopaedic trauma research.",1,https://api.osf.io/v2/files/5bbcfbb90463cb0018cceac4/,290,https://engrxiv.org/7c8kz/,10.31224/osf.io/7c8kz,,2018-10-09T19:18:52.729555,2018-10-09T20:08:04.440950 | |
| 26z9n,"Fully automated image-based estimation of postural point-features in children with cerebral palsy using deep learning","Objective: To automate identification of postural point-features from colour videos of children with neuromotor disability, during clinical assessment. The automatic identification of 13 points of interest (2, 6, 2, 3 points on the head, trunk, pelvis, arm respectively) is required to estimate the location and orientation of head, trunk, and arm segments, from videos of the clinical test “Segmental Assessment of Trunk Control” (SATCo) which is a test of seated postural control. Methods: Three expert operators manually annotated 13 point-features in every fourth image of 177 short (5-10 second) videos (25 Hz) showing 12 children with cerebral palsy (ages: 4.52 ±2.4, male: 9), participating in SATCo testing. Linear interpolation for the remaining images resulted in 30,825 annotated images. Mean-pooling and max-pooling convolutional neural networks were trained with cross-validation, giving held-out test results for all children. Results: The point-features were estimated with error 4.40 ±3.75 pixels (mean-pooling), and 4.49 ±4.45 pixels (max-pooling), at approximately 100 images per second. Trunk segment angles (head, neck, 6 thoraco-lumbar-pelvic segments) were estimated with error 6.4° ±2.8° allowing accurate classification (F1 > 80%) of deviation from a reference posture at thresholds up to 3°, 3°, 2° respectively. Contact between arm point features (elbow, wrist) and supporting surface was classified at F1 = 80.5%. Conclusion and Significance: This study demonstrates, for the first time, a technical solution to automate identification of i) a sitting segmental-posture including individual trunk segments, ii) changes away from that posture, and iii) support from the upper limb, required for the clinical SATCo.",1,https://api.osf.io/v2/files/5bb752a73d0180001ce9ef90/,482,https://engrxiv.org/26z9n/,10.31224/osf.io/26z9n,,2018-10-05T12:28:10.672731,2019-03-26T13:46:29.770502 | |
| 75muh,"A Pull-down Dynamic Analysis of Two-Span Steel Frames Subjected to Progressive Collapse","Progressive collapse, also known as disproportionate collapse, describes a chain reaction of structural element failures in which a primary structural element failure results in the failure of adjoining structural elements. It eventually causes widespread structural damages and a disproportionate collapse. While high level finite-element models incorporating non-linear dynamic analysis will produce more realistic results in progressive collapse scenarios, they are computationally time consuming. Therefore, the development of a non-linear time history pull-down model that is validated with experimental results would be beneficial for producing acceptable and efficient design solutions, particularly for practicing structural engineers. In this paper, a non-linear time history pull-down model of a two-span steel frame is analyzed in ETABS. The ETABS model results are compared with experimental results of two steel frames with two-spans conducted by the National Institute of Standards and Technology (NIST). The NIST experiments include beam-column assemblies from the second-floor framing system of a ten-story building and each span is 20 feet long. The numerical results from ETABS pull-down analysis showed good agreement with the results from the NIST experimental study.",1,https://api.osf.io/v2/files/5bb6762c2721c80015fa6c61/,443,https://engrxiv.org/75muh/,10.31224/osf.io/75muh,,2018-10-04T20:22:25.736872,2018-10-26T20:11:29.811198 | |
| av5su,"Practical DOE-Based Approach for Predicting Impact of Stress and Deformation in SLM Overhanging Features During Product Design","As additive manufacturing (AM) processes become more refined and widely used, it is essential for engineers and production managers to fully understand the processes in order to effectively use them within production systems. Unfortunately, most of the existing solutions for analyzing AM processes are too complex and specialized for use in a practice-based setting. The present study seeks to address aspects of this problem by developing a simple first-principles finite element model for the selective laser melting (SLM) AM process and a rigorous experiment to analyze the process in terms of its input factors. This model and experiment can provide much useful and easily understood data to the designers and production managers including SLM in their process flow. The experiment was verified and run fully in order to demonstrate it, producing information about the influence of five major input factors and their many interactions during the processing of a part with an overhanging feature",1,https://api.osf.io/v2/files/5bb31556dc1a760019cb5180/,395,https://engrxiv.org/av5su/,10.31224/osf.io/av5su,,2018-10-02T06:56:50.568957,2019-01-17T20:33:53.235584 | |
| bnupe,"Study on Shell-and-Tube Heat Exchanger Models with Different Degree of Complexity for Process Simulation and Control Design","Many commercial solar thermal power plants rely on indirect thermal storage systems in order to provide a stable and reliable power supply, where the working fluid is commonly thermal oil and the storage fluid is molten salt. The thermal oil - molten salt heat exchanger control strategies, to charge and discharge the thermal storage system, strongly affect the performance of the whole plant. Shell-and-tube heat exchangers are the most common type of heat exchangers used in these facilities. With the aim of developing advanced control strategies accurate and fast dynamic models of shell-and-tube heat exchangers are essential. For this reason, several shell-and-tube heat exchanger models with different degrees of complexity have been studied, analyzed and validated against experimental data from the CIEMAT-PSA molten salt test loop for thermal energy systems facility. Simulation results are compared in steady-state as well as transient predictions in order to determine the required complexity of the model to yield accurate results.",1,https://api.osf.io/v2/files/5bb22b186e78da001631e856/,1816,https://engrxiv.org/bnupe/,10.31224/osf.io/bnupe,10.1016/j.applthermaleng.2017.06.129,2018-10-01T14:14:14.737908,2018-10-01T14:18:13.168549 | |
| msbrf,"Design and Experimental Validation of a Computational Effective Dynamic Thermal Energy Storage Tank Model","Concentrating solar thermal power plants rely in thermal energy storage systems in order to provide a stable power supply. However, they might not been able to meet power plant demands, mainly because of their storage sizes which are restricted due to economic reasons. One way of mitigating this effect is to control in an optimal way the charging and discharging processes. For the design and validation of advanced control strategies, an accurate dynamic model is essential. For this reason, a dynamic thermal energy tank model intended to be used in concentrating solar thermal power plant models is presented in this paper. The developed tank model is validated in charging and discharging processes and also at rest state in order to validate thermal losses dynamics. Simulation results are compared against experimental data from the CIEMAT-PSA molten salt testing facility.",1,https://api.osf.io/v2/files/5bb229e3118e1200191751f5/,392,https://engrxiv.org/msbrf/,10.31224/osf.io/msbrf,10.1016/j.energy.2017.11.017,2018-10-01T14:09:21.765074,2018-10-01T14:12:56.544937 | |
| 6zps9,"A Novel Heat Exchanger Design Method Using a Delayed Rejection Adaptive Metropolis Hasting Algorithm","In this study, a shell-and-tube heat exchanger (STHX) design based on seven continuous independent design variables is proposed. Delayed Rejection Adaptive Metropolis hasting (DRAM) was utilized as a powerful tool in the Markov chain Monte Carlo (MCMC) sampling method. This Reverse Sampling (RS) method was used to find the probability distribution of design variables of the shell and tube heat exchanger. Thanks to this probability distribution, an uncertainty analysis was also performed to find the quality of these variables. In addition, a decision-making strategy based on confidence intervals of design variables and on the Total Annual Cost (TAC) provides the final selection of design variables. Results indicated high accuracies for the estimation of design variables which leads to marginally improved performance compared to commonly used optimization methods. In order to verify the capability of the proposed method, a case of study is also presented, it shows that a significant cost reduction is feasible with respect to multi-objective and single-objective optimization methods. Furthermore, the selected variables have good quality (in terms of probability distribution) and a lower TAC was also achieved. Results show that the costs of the proposed design are lower than those obtained from optimization method reported in previous studies. The algorithm was also used to determine the impact of using probability values for the design variables rather than single values to obtain the best heat transfer area and pumping power. In particular, a reduction of the TAC up to 3.5% was achieved in the case considered.",1,https://api.osf.io/v2/files/5bb2285671746000185005d1/,371,https://engrxiv.org/6zps9/,10.31224/osf.io/6zps9,10.1016/j.applthermaleng.2018.04.028,2018-10-01T14:03:36.599743,2018-10-01T14:11:29.173569 | |
| 7bw4y,"Steady-state and dynamic validation of a parabolic through collector model using the ThermoCycle Modelica library","Small-capacity (<200 kWel) concentrated solar power plants has been recognized as a promising technology for micro power applications. In particular, parabolic through collectors have been identified as the most promising focusing technology. In this context, physics-based dynamic model of parabolic through constitutes a significant tool for the further development of the technology, allowing to evaluate and optimize response times during transients, or to implement and test innovative control strategies. In this contribution, the dynamic model of a parabolic trough line t based on the ThermoCycle Modelica library is validated against steady-state and transient experimental results from the parabolic through test loop available at the Plataforma Solar de Almería, Spain. The simulation results are in good agreement with the measurements, both in steady-state and in transient conditions. The validated model is readily usable to investigate demanding dynamics-based problems for low capacity solar power systems.",1,https://api.osf.io/v2/files/5bb2259a118e12001a170518/,418,https://engrxiv.org/7bw4y/,10.31224/osf.io/7bw4y,,2018-10-01T13:55:31.523064,2018-10-01T14:10:44.808795 | |
| c4qr9,"Memristors for the curious outsiders","We present both an overview and a perspective of recent experimental advances and proposed new approaches to performing computation using memristors. A memristor is a 2-terminal passive component with a dynamic resistance depending on an internal parameter. We provide an brief historical introduction, as well as an overview over the physical mechanism that lead to memristive behavior. This review is meant to guide nonpractitioners in the field of memristive circuits and their connection to machine learning and neural computation.",1,https://api.osf.io/v2/files/5bae4254118e12001a144c09/,621,https://engrxiv.org/c4qr9/,10.31224/osf.io/c4qr9,10.3390/technologies6040118,2018-09-28T15:14:22.615434,2018-12-12T13:08:03.134206 | |
| 9dy5x,"IoT Network Segmentation When Sensors Fail","This draft presents a fault-tolerant network segmentation system for the Internet of Things (IoT). When devices of the IoT malfunction or fail, recovery needs to be performed to maintain system functionalities. In modern ad hoc networks like mobile ad hoc networks (MANETs), devices usually form dynamical clusters to collaboratively handle highly diverse sensing environments. To recover cluster information when parts of the IoT are not functioning, this study develops a centroid-free network segmentation algorithm that diverts dependency on centroids into empirical-space kernel matrices. The original problem of handling nonvectorial centroids is deduced to kernel matrix estimation.",1,https://api.osf.io/v2/files/5bace72871746000184c321d/,309,https://engrxiv.org/9dy5x/,10.31224/osf.io/9dy5x,,2018-09-27T14:23:27.086166,2018-09-27T14:37:57.971015 | |
| 8cwj2,"Solar energy-assisted frost prevention in horticulture applications: integrated framework and parametric CFD modeling","Prevention of frost in horticulture is important, but challenging, and its realization, | |
| especially using green-energy sources, will have a huge societal impact. | |
| In this paper, first we suggest an integrated solar | |
| photovoltaics (PV)-assisted framework where solar energy will be used as a secondary application for frost | |
| prevention (the primary application is electricity production for grid). Optimal design and operation of | |
| the suggested integrated system require detailed thermal modeling of air dynamics in the orchard, | |
| integrated system optimization and control tasks. Second, in this paper | |
| we address the first task above: development of a novel, sophisticated parametric computational fluid dynamics (CFD) | |
| model for orchard air thermal dynamics for different orchard parameters (such as fruit type, climate, the number of trees, | |
| their sizes, distance between them, etc.) and boundary/initial conditions. | |
| Finally, the use of developed parametric CFD model is demonstrated through a case study to calculate the minimal thermal | |
| energy required to prevent frost under different frost levels in a test apricot orchard located in Malatya, Turkey, which is | |
| the world capital for dry apricot production.",1,https://api.osf.io/v2/files/5bac37e771746000154bc7b3/,311,https://engrxiv.org/8cwj2/,10.31224/osf.io/8cwj2,,2018-09-27T01:58:03.886134,2018-09-27T02:31:32.011726 | |
| r4nmy,"The Disaster Resilience Value of Rooftop Solar in Residential Communities","Distributed energy resources can enhance community resilience to power outages in the aftermath of natural disasters. We develop a method to quantify the resilience value that rooftop solar can provide to residential neighborhoods. We group homes into geographical clusters and simulate the effect of a disaster that disables the electric grid and damages some of the homes. We then use historical energy consumption and solar irradiance data to estimate the likelihood that each cluster could meet its own energy needs given a defined level and pattern of rooftop solar adoption. As a case study, we apply the method to single family homes in San Carlos, California, subjected to an earthquake based on the 1906 San Francisco event. We characterize the impact on resilience of increasing adoption of rooftop solar and of grouping homes into resilience clusters for energy sharing. Policy intervention can ensure more geographically uniform adoption of solar and therefore more even resilience. We evaluate the effect and cost of such an intervention, finding that a modest subsidy can make a notable difference in evening out resilience across a community.",1,https://api.osf.io/v2/files/5baa73319108ce0017f6f14b/,173,https://engrxiv.org/r4nmy/,10.31224/osf.io/r4nmy,,2019-10-21T20:33:28.873953,2019-10-22T20:13:07.306522 | |
| xjztd,"Self-Aware Autonomous City: From Sensing to Planning","This article presents a knowledge mining model, where a city can plan its development based on existing knowledge during city expansion, for example, telecommunication resource allocation and crowd forecast in a new region. Unlike most works that focused on Internet-of-Things (IoT) sensing, this study is aimed at urban planning by using harvested data, from the perspective of city architects. For large-scale metropolitan areas, a massive amount of data is generated every day, either from static surveys or dynamic IoT sensing. For urban planners, data collection is not their prior concerns. How to transfer harvested knowledge from exiting parts of the city to suburban/rural/ untapped areas is a new challenge. This is because those areas still lack sufficient statistics, and the density of IoT deployment is low. Therefore, development is risky and uncertain. To exploit new regions requires knowledge inference. Such a transition needs data interpretation from historical city dynamics, involving sensor deployment, human activities, and resource allocation in the vicinity. With the proposed model of this article, a city can estimate the requirement for resources when the peripheral areas on the outskirts of a city develops. The same model can be applied to enterprise sides for resource deployment, and applications are not merely limited to governments.",1,https://api.osf.io/v2/files/5ba876369108ce0015f6646a/,421,https://engrxiv.org/xjztd/,10.31224/osf.io/xjztd,10.1109/MCOM.2019.1800628,2018-09-24T05:37:30.886326,2019-05-17T10:10:18.770513 | |
| upk7g,"Design and Preliminary Testing of a Continuum Assistive Robotic Manipulator","The application of continuum manipulators as assistive robots is discussed and tested through the use of Bendy ARM, a simple tendon driven continuum manipulator prototype. Two rounds of user testing were performed to evaluate the potential of this arm to aid people living with disabilities in completing activities of daily living. In the first round of user testing, 14 able-bodied subjects successfully completed the prescribed task (pick-and-place) using multiple control schemes after being given a brief introduction and one minute of practice with each scheme. In the second round of user testing, subjects (n=3) demonstrated between 29.5 and 48.9 percent improvement in completion time across twelve trials of a peg-in-hole task, and between 8.4 and 33.8 percent improvement across six trials of a task involving opening and closing a drawer. Based on these results, it is posited that continuum manipulators merit further consideration as a safer and more cost-effective alternative to existing commercially available assistive robotic manipulators.",1,https://api.osf.io/v2/files/5ba54f869108ce0017f2a52c/,563,https://engrxiv.org/upk7g/,10.31224/osf.io/upk7g,10.3390/robotics8040084,2018-09-21T20:09:33.289651,2019-09-26T12:21:39.859819 | |
| zwmqx,"Feasibility study of a hot-air tethered aerostat system","The lifting gas used in Lighter-than-Air systems is usually Helium or Hydrogen. Helium is a rare gas and hence very expensive and Hydrogen, though relatively less expensive and easily available, is highly inflammable. Hot air has been used as an LTA gas since the first flight of a balloon in the 18th century, but its utilization in tethered aerostat systems has been limited. The objective of this project is to examine the feasibility of using hot air as the LTA gas in a practical tethered aerostat system. In this study, the thermal analysis of hot air envelope was conducted to predict heat losses and power requirements. This was followed by an experimental study to validate the theoretical values obtained from the thermal model, in which an electrical heating system was inserted inside a spherical envelope made of rip-stop nylon with a fire-retardant coating. Heat loss predictions were extrapolated for a larger size working prototype and feasibility studies were performed. The experimental heat loss predictions were far higher than those obtained using the thermal model available in literature. The power requirement for the smallest possible spherical working prototype made of Polyurethane coated envelope, with a radius of 2.3 m was estimated to be more than 66 kW. However, for an envelope fabricated with a proprietary material named aerofabrix®, around 33% reduction in the power requirement was estimated. These results show a promise for a hot-air based tethered aerostat system, but with several design and operational challenges, which will be highlighted in the paper.",1,https://api.osf.io/v2/files/5ba492f85a7172001be423dd/,318,https://engrxiv.org/zwmqx/,10.31224/osf.io/zwmqx,,2018-09-21T06:50:14.835902,2018-09-24T18:01:50.469818 | |
| xuvay,"Heat treatment effects on three-dimensional morphology of chromium carbide in AISI D2 tool steel studied by serial sectioning method","We developed a three-dimensional microstructure analysis system based on the manual serial sectioning method to evaluate the heat treatment effects on chromium carbide size and morphology in AISI D2 tool steel. Two heat treatment factors, austenitizing and tempering temperature were investigated. The results show that increasing in austenitizing temperature leads to further carbide precipitation after the tempering process and increasing in the tempering temperature causes precipitate smaller secondary carbides even more than the primary carbides.",1,https://api.osf.io/v2/files/5b99221a296328001ac70577/,313,https://engrxiv.org/xuvay/,10.31224/osf.io/xuvay,,2018-09-12T14:28:35.063576,2018-09-12T14:39:59.234614 | |
| 7b4f8,"A Large Range of Motion 3D MEMS Scanner with Five Degrees of Freedom","In this paper, we discuss a novel, mixed mode 3D XYZ scanner built within a single foundry process. The device has a large range of motion in X, Y and Z (14.0 μm in X,Y and 97.9 μm in Z) and can also rotate about two axes (7.4°), making it a 5 degree of freedom scanner. Vertical actuation can be accomplished with both thermal actuators, which have a larger range of motion, and capacitive actuators, which are faster, responding fully up to 3.2 kHz. Although it is useful for many applications, including scanning probe microscopy, micrometer scale optical microscopy, and manipulation of biological objects, the device was designed to be a 3D scanner for spray-painting atoms upon a surface with nanoscale precision and resolution for nanofabrication. Demonstrating the ability to combine the device with other complicated MEMS systems, it is integrated with an XY scanner designed to serve as a shutter to control the flow of atoms. The full system has 7 degrees of freedom and 12 actuation motors, and because it is built in a low cost commercial foundry with a robust, stable process, it is easy and inexpensive to fabricate multiple copies or integrate into other complicated systems, making a system of systems.",1,https://api.osf.io/v2/files/5b980892715bea00174f1c1f/,327,https://engrxiv.org/7b4f8/,10.31224/osf.io/7b4f8,10.1109/JMEMS.2018.2886653,2018-09-11T19:02:28.356871,2019-01-16T17:15:12.031065 | |
| e2679,"Effects of Heat Affected Zone Softening Extent on the strength of Advanced High Strength Steels Resistance Spot Weld","Resistance spot welds made from Advanced High Strength Steels (AHSS) exhibit Heat Affected Zone (HAZ) softening due to the tempering of pre-existing martensite phase and the consequent decomposition into a mixture of ferrite and cementite. Despite the high strength level for the base metal, the occurrence of HAZ softening may lead to inferior joint strength during Tension-Shear (TS) and Cross-Tension (CT) testing. In this work, we investigated the effects of the HAZ softening on the global loading response for AHSS steels with three different volume fractions of martensite. Microhardness mapping was used as a measure of martensite tempering and extent of softening. Based on the data, the softening was identified in the sub-critical heat affected zone. Hardness drop with the magnitude of 6%, 18%, and 42% was observed in steels with 16%, 52% and 100% of martensite volume fraction (MVF), respectively. In order to model the welded joint loading response using finite element methods (FEM), there is a need to represent the softening in terms of stress-strain relationships. In this work, local stress-strain curves for different weld zones were obtained by scaling the base metal constitutive properties with local hardness ratio. Finite element (FE) simulations of Tension-Shear tests showed that HAZ softening can affect the Tension-Shear load capacity of specimens more significantly when the base metal tensile strength is above 1000 MPa. The paper will discuss the validity of the above finite element approach for describing experimental results and future directions.",1,https://api.osf.io/v2/files/5b92a0222c77f700167d36b5/,435,https://engrxiv.org/e2679/,10.31224/osf.io/e2679,,2018-09-07T16:05:21.227873,2018-09-07T16:35:42.725909 | |
| mkbwv,"Analysis of C1, C2, and C10 through C33 particle-phase and semi-volatile organic compound emissions from heavy-duty diesel engines","To meet increasingly stringent regulations for diesel engines, technologies such as combustion strategies, aftertreatment components, and fuel composition have continually evolved. The emissions reduction achieved by individual aftertreatment components using the same engine and fuel has been assessed and published previously (Liu et al., 2008a, Liu et al., 2008b, Liu et al., 2008c). The present study instead adopted a systems approach to evaluate the net effect of the corresponding technologies for model-year 2004 and 2007 engines. The 2004 engine was equipped with an exhaust gas recirculation (EGR) system, while the 2007 engine had an EGR system, a crankcase emissions coalescer, and a diesel particulate filter. The test engines were operated under the transient federal test procedure and samples were collected with a source dilution sampling system designed to stimulate atmospheric cooling and dilution conditions. The samples were analyzed for elemental carbon, organic carbon, and C1, C2, and C10 through C33 particle-phase and semi-volatile organic compounds. Of the more than 150 organic species analyzed, the largest portion of the emissions from the 2004 engine consisted of formaldehyde, acetaldehyde, and naphthalene and its derivatives, which were significantly reduced by the 2007 engine and emissions technology. The systems approach in this study simulates the operation of real-world diesel engines, and may provide insight into the future development of integrated engine technology. The results supply updated information for assessing the impact of diesel engine emissions on the chemical processes, radiative properties, and toxic components of the atmosphere.",1,https://api.osf.io/v2/files/5b8d95cdcc53a90016376382/,363,https://engrxiv.org/mkbwv/,10.31224/osf.io/mkbwv,10.1016/j.atmosenv.2009.11.036,2018-09-03T20:17:50.932967,2018-09-03T20:20:54.012269 | |
| dv28m,"Experiences with inquiry-based learning in an introductory mechanics course","Inquiry-based learning is an educational approach that allows the student to take ownership over the education process by self-identifying a problem and formulating their own solution. The application of this method of teaching was explored in an introductory mechanics course taken by both engineering and engineering technology students. Students were tasked with applying the principles of fundamental static equilibrium analysis to objects found in their normal surroundings. The deliverable for this assignment consisted of a photograph of an object they found to be in static equilibrium and a short description of how the state of the object could be described mathematically. Student submissions for this task exhibited a wide range of quality and imagination. Examples of student work are presented along with discussion of lessons learned and recommendations for the use of this method in the future. The overall student response to this task was positive and thus these efforts will be expanded.",1,https://api.osf.io/v2/files/5b8d92fbcc53a90018357a0a/,255,https://engrxiv.org/dv28m/,10.31224/osf.io/dv28m,,2018-09-03T20:03:45.373509,2018-09-03T20:21:08.316181 | |
| 5hz2v,"Low-cost, take-home, beating heart simulator for health-care education","Intended for medical students studying the evaluation and diagnosis of heart arrhythmias, the beating heart arrhythmia simulator combines visual, auditory, and tactile stimuli to enhance the student's retention of the subtle differences between various conditions of the heart necessary for diagnosis. Unlike existing heart arrhythmia simulators, our simulator is low cost and easily deployable in the classroom setting. A design consisting of solenoid actuators, a silicon heart model, and a graphical user interface has been developed and prototyped. Future design development and conceptual validation is necessary prior to deployment.",1,https://api.osf.io/v2/files/5b8d912e6a59a5001671e12d/,239,https://engrxiv.org/5hz2v/,10.31224/osf.io/5hz2v,10.3233/978-1-60750-706-2-57,2018-09-03T19:57:18.242095,2018-09-03T20:21:23.014551 | |
| an6cm,"Determination of surgical robot tool force requirements through tissue manipulation and suture force measurement","Through the use of a cadaveric porcine model, forces necessary for manipulation of the abdominal organs were evaluated using an instrumented probe. Additionally, forces for tissue puncture, knot tightening, and suture breakage have been measured in order to determine the requirements placed upon the design of novel robotic surgical tools. The break forces for a variety of suture sizes and types were evaluated including sizes 3-0 through 7-0 polypropylene, size 1 polybutestor, size 4-0 chromic gut, and size 6-0 braided polyester. Tests of the tissue puncture force and knot tightening forces were carried out using the same instrumented probe, while the suture break forces were measured using a tension testing machine. The measured forces were found to compare well against the literature and provide a good basis from which to design robotic surgical tools with the appropriate capabilities.",1,https://api.osf.io/v2/files/5b8d8f896a59a5001671dfc8/,250,https://engrxiv.org/an6cm/,10.31224/osf.io/an6cm,10.1115/1.3590369,2018-09-03T19:49:47.317994,2018-09-03T20:21:44.162458 | |
| dqg7m,"Achieving dexterous manipulation for minimally invasive surgical robots through the use of hydraulics","Existing robotic surgical platforms face limitations which include the balance between the scale of the robot and its capability in terms of range of motion, load capacity, and tool manipulation. These limitations can be overcome by taking advantage of fluid power as an enabling technology with its inherent power density and controllability. As a proof-of-concept for this approach, we are pursuing the design of a novel, dexterous robotic surgical tool targeted towards transgastric natural orifice surgery. | |
| The design for this hydraulic surgical platform and the corresponding analysis are presented to demonstrate the theoretical system performance in terms of tool positioning and input requirements. The design involves a combination of a novel 3D valve, hydraulic artificial muscles, and multi-segmented flexible manipulator arms that fit in the lumen of an endoscope. A dynamic model of the system is created. Numerical simulations show that a hydraulic endoscopic surgical robot can produce the desired performance without using large external manipulators such as those employed by conventional surgical robots. They also provide insight into the component interactions and input response of the system. Future work will include manufacturing a prototype to validate the concept and the numerical models.",1,https://api.osf.io/v2/files/5b8d8e166a59a500187027c0/,276,https://engrxiv.org/dqg7m/,10.31224/osf.io/dqg7m,10.1115/DSCC2012-MOVIC2012-8685,2018-09-03T19:43:46.522870,2018-09-03T20:21:54.137847 | |
| b87pf,"Framework for Patient Service Queue System for Decision Support System on Smart Health Care","Improving the service of patient care in hospitals is important for all, prioritizing patient safety in the event of a sudden or catastrophic attack, in which case the priority is to provide services to the patient. In such situations a decision system is needed, in order for the system to be right and not wrong to do a decision because the handling of this issue is closely related to the patient's life. The patient handling technology supports highly smart healthcare technology, which of course is part of the Smart city. The purpose of this research is to get Smart Health Care model with Decision Support System model approach in public health service, where Decision Support System model for Smart Health Care can solve health service problem in order to make maximum service for patient.",1,https://api.osf.io/v2/files/5b8ca255cc53a90016363318/,324,https://engrxiv.org/b87pf/,10.31224/osf.io/b87pf,10.14419/ijet.v7i2.13.16915,2018-09-03T03:02:29.330432,2018-09-03T15:23:33.040407 | |
| vfc98,"PWM as a Low Cost Method for the Analog Control of MEMS Devices","In this paper we discuss the use of pulse width modulation (PWM) to control analog MEMS devices. We achieve precise linear analog control of MEMS by applying a PWM signal with a frequency well above the system's mechanical natural frequency. We first demonstrate this using a parallel plate actuator and comb-drive, then extend the technique to control a commerical deformable mirror. Such an approach allows the system designer to replace expensive drive electronics such as high precision DACs and high voltage, linear amplifiers with a simple on-off switch. Advancements in the electronics industry tend to make precise timing cheaper and faster; our approach exploits these long term trends to create low cost control circuits. We also show how PWM control can linearize the positional response of devices where typically the position would depend quadratically on the applied, analog voltage.",1,https://api.osf.io/v2/files/5b86f3aab57ff50017ec9602/,385,https://engrxiv.org/vfc98/,10.31224/osf.io/vfc98,10.1109/JMEMS.2019.2891205,2018-08-29T19:43:25.549343,2019-01-23T20:37:01.968905 | |
| 6whu7,"Channels with Action Dependent States and Additional Private Messages","In channels with action dependent states, a message is conveyed using two encoders operating sequentially, viz. | |
| an action encoder and a channel encoder. The actions drive the output of a discrete-memoryless channel (DMC), | |
| which in turn forms the state process for the DMC between the channel encoder and receiver. Assuming non-causal | |
| knowledge of the state-process at the channel encoder, a single letter characterization of the capacity is known in | |
| the discrete memoryless case. | |
| We consider the action dependent state channel where an additional private message needs to be communicated | |
| by the channel encoder. In addition, we consider a common reconstruction (CR) of the state at the channel encoder | |
| and decoder. Capacity characterizations for the discrete memoryless and Gaussian versions are presented. As a | |
| consequence, we settle the capacity characterization of the Gaussian action dependent channel with only a common | |
| message and CR. We further show that the availability of strictly causal state feedback to the action encoder, even | |
| with randomization allowed, does not improve the capacity of the action dependent state channel.",1,https://api.osf.io/v2/files/5b7ea4718c6d9f001aae8800/,271,https://engrxiv.org/6whu7/,10.31224/osf.io/6whu7,,2018-08-23T12:13:04.759276,2018-08-23T20:43:05.116533 | |
| 38ub9,"Modeling of the Mechanical Behavior of 3D Bioplotted Scaffolds Considering the Penetration in Interlocked Strands","Three-dimensional (3D) bioplotting has been widely used to print hydrogel scaffolds for tissue engineering applications. One issue involved in 3D bioplotting is to achieve the scaffold structure with the desired mechanical properties. To overcome this issue, various numerical methods have been developed to predict the mechanical properties of scaffolds, but limited by the imperfect representation of one key feature of scaffolds fabricated by 3D bioplotting, i.e., the penetration or fusion of strands in one layer into the previous layer. This paper presents our study on the development of a novel numerical model to predict the elastic modulus (one important index of mechanical properties) of 3D bioplotted scaffolds considering the aforementioned strand penetration. For this, the finite element method was used for the model development, while medium-viscosity alginate was selected for scaffold fabrication by the 3D bioplotting technique. The elastic modulus of the bioplotted scaffolds was characterized using mechanical testing and results were compared with those predicted from the developed model, demonstrating a strong congruity between them. Once validated, the developed model was also used to investigate the effect of other geometrical features on the mechanical behavior of bioplotted scaffolds. Our results show that the penetration, pore size, and number of printed layers have significant effects on the elastic modulus of bioplotted scaffolds; and also suggest that the developed model can be used as a powerful tool to modulate the mechanical behavior of bioplotted scaffolds.",1,https://api.osf.io/v2/files/5b7c3c772da7bb001b7112f0/,269,https://engrxiv.org/38ub9/,10.31224/osf.io/38ub9,10.3390/app8091422,2018-08-21T16:32:19.506126,2018-08-21T17:42:58.624597 | |
| z892e,"Design of Soft Continuum Manipulators Using Parallel Asymmetric Combination of Fiber Reinforced Elastomers","Soft continuum manipulators have large workspace, dexterity and adaptability, but at the cost of complex design construction highlighted by concatenating several individually controlled serial segments. In this paper, we propose a new design | |
| architecture for a soft continuum manipulator composed of a parallel combination of pneumatic actuators. The BR2 manipulator, featured in this paper is asymmetric as it combines one soft bending (B) actuator and two soft rotating (R2) actuators, as opposed to state of the art symmetric architectures that adopt bending segments. Spatial deformation modes are achieved by combining curvature and torsion of the individual actuators. This paper formulates a forward analysis method based on Cosserat rod mechanics to predict the spatial deformation of the manipulator under the effect of external loads with an accuracy less than 9 % of the manipulator length. The model takes into account ‘the coupling effect’ inherent to the asymmetric combination, where pressurizing the rotating actuator attenuates the bending | |
| curvature and vice versa. Consequently, the paper studies the optimal design of the manipulator constituents that minimize the coupling, and thus maximize the workspace and dexterity. A detailed performance study of the BR2 manipulator on a | |
| swiveling base demonstrates a spatial workspace quantified by an axisymmetric area, and sufficient dexterity such that at least 87% of the workspace can be approached with two or more orientations. These are validated through obstacle avoidance, and a pick and place task. The manipulator is also capable of | |
| whole arm manipulation by spiraling along cylindrical objects of varying diameters. These performance attributes surpass any other single segment module and is a potential building block for constructing customized continuum manipulators.",1,https://api.osf.io/v2/files/5b7afcdcd4676c0017ab749d/,403,https://engrxiv.org/z892e/,10.31224/osf.io/z892e,,2018-08-20T17:46:34.603428,2018-08-20T19:47:33.379897 | |
| eyx6u,"Bendy ARM 2.0: Continuum Arm Manipulator Refinement and Control for Assistive Technology","Rigid link robots currently dominate the market for manipulators in assistive technology, though research on continuum robots for assistive technology has been developing over recent years. These types of robots have a continuous backbone that allows them to have infinite degrees of freedom, making them highly compliant, however this brings challenges in terms of modelling and control. Additionally, materials for this type of application require specific qualities. In this work, we attempt to address these problems while designing a continuum arm suitable for assistive technology applications. Bendy ARM 2.0 is a revised version of the first Bendy ARM robot to accomplish these goals. In its first iteration, Bendy ARM had limitations in its mechanical function, such as the structural performance of the backbone, which decreased the accuracy in positional control. Nitinol was tested as a new backbone material but failed during testing so a low density polyethylene was chosen. Cable conduits were added to help reduce the mechanical coupling between the proximal and distal segments of the manipulator. Motion processing units (MPU) are utilized to gather tilt angles and provide direction for automated movements. Due to the arms natural rotation, this data alone was not enough to consistently control and place the robot. With the information gathered, further consideration of backbone material and usage of MPU data is required for an automatable robot.",1,https://api.osf.io/v2/files/5b7737e1410f920017e53f70/,406,https://engrxiv.org/eyx6u/,10.31224/osf.io/eyx6u,,2018-08-17T21:05:10.331841,2018-08-18T03:29:44.200065 | |
| yqgkc,"Bounded Rationality and Risk Management in Thermal Soaring","Awareness and management of the risk of failing to encounter lift is fundamental to thermal soaring. When the weather changes or a thermal is missed the pilot may be exposed to a greater risk of landing out. In these situations the pilot may need to alter strategies in order to minimize risk exposure at the expense of speed, often referred to as ""gear shifting."" In this work, we explore several models to explain why small changes in the environment can cause large changes in risk exposure, requiring this shifting. We also examine several flight strategies in simulation to define the relative risk and reward for adopting various levels of risk tolerance and for failing to ""shift gears"" when the risk of landing out increases.",1,https://api.osf.io/v2/files/5b771b75410f920016e53254/,840,https://engrxiv.org/yqgkc/,10.31224/osf.io/yqgkc,,2018-08-17T19:19:35.666702,2018-08-17T20:57:39.820001 | |
| wgm72,"An overview of the role of Machine Learning in hydraulic and hydrological modeling","We provide an overview of Machine learning (ML) | |
| and its role in hydrology and hydraulic. The aim is | |
| to ease the access of researchers in the latter fields | |
| to the techniques in ML.",1,https://api.osf.io/v2/files/5b73ffb7b79df200180f504f/,326,https://engrxiv.org/wgm72/,10.31224/osf.io/wgm72,,2018-08-15T10:28:00.505479,2018-08-15T19:21:12.196494 | |
| 54m3x,"Fast early flood warning systems exploiting catchment specific behavior","We present a catchment specific emulator based on | |
| non-linear shallow water equations to be used for | |
| early flood warning system in real time.",1,https://api.osf.io/v2/files/5b73fd3878b9a000165d3969/,263,https://engrxiv.org/54m3x/,10.31224/osf.io/54m3x,,2018-08-15T10:18:53.525830,2018-08-15T19:20:44.575877 | |
| y4ahm,"Flood prediction in a compound channel using machine learning techniques","Flood prediction in a synthetic trapezoidal, com- | |
| pound channel is made, using an emulator of the | |
| computationally demanding 2D hydrodynamic | |
| model FLOW-R2D.",1,https://api.osf.io/v2/files/5b73fbcb78b9a000175d0877/,271,https://engrxiv.org/y4ahm/,10.31224/osf.io/y4ahm,,2018-08-15T10:14:04.503485,2018-08-15T19:19:39.951113 | |
| 5dn49,"ELECTROPOLISHING OF ADDITIVELY MANUFACTURED HIGH CARBON GRADE 316 STAINLESS STEEL","Improving surface finishing is the critical step in the application of an additively manufactured (AM) component. This paper provides insights into the electropolishing route for the surface improvement of the AM component made up of 316 stainless steel with >6% carbon. We have discussed the Taguchi design of experiment-based process optimization to understand the role of various process parameters. Profilometry and scanning electron microscopy were performed to study the electropolished and unpolished areas of the AM components. Optical profilometry provided an estimate of the amount of material to be removed to achieve shining and smooth AM surface. Optical profilometry also provided analysis of several roughness parameters on the electropolished surface. Electropolishing was effective in reducing the surface roughness below ~0.1 µm RMS. This sub µm RMS roughness makes an AM component suitable for major engineering applications. SEM showed distinctively different microstructure on the electropolished surface. We also conducted water contact angle study and spectroscopic reflectance study on electropolished and unpolished AM component surface. Our study revealed that electropolishing is a highly promising route for improving the surface finishing of AM components.",1,https://api.osf.io/v2/files/5b73a0ff78b9a000165ce4dd/,301,https://engrxiv.org/5dn49/,10.31224/osf.io/5dn49,,2018-08-15T03:48:47.599984,2018-08-15T19:16:47.530000 | |
| 3me2j,"Reducing the Roughness of Internal Surface of an Additive Manufacturing Produced Steel Component by Chempolishing and Electropolishing","Reducing the surface roughness of an additively manufactured (AM) component is one of the most critical factors in determining the suitability of an AM component. As produced surface roughness of an AM component is very high. This prohibits the direct utilization of AM components for the intended applications. For most of the engineering applications, surface roughness must be reduced significantly. Reducing surface roughness is exponentially more challenging for the internal surfaces of a component. This paper reports research in the area of post processing interior surfaces of an AM component. Electropolishing and chemical polishing (chempolishing) methods were applied to reduce the surface roughness of the internal surface. It was found that chempolishing was very effective in simultaneously reducing the internal and external surface roughness of steel AM components for any complicated AM shape and geometry. The electropolishing methodology employed was very effective in reducing the surface roughness of the internal or external surfaces as long as a counter electrode could be positioned in the proximity of the surface to be polished. However, electropolishing produced better performance on the outer surfaces as compared to chempolishing. This paper summarizes research efforts to tackle the critical issue of reducing the surface roughness of complex AM components.",1,https://api.osf.io/v2/files/5b70fe5c90a7e0001788412e/,530,https://engrxiv.org/3me2j/,10.31224/osf.io/3me2j,,2018-08-13T03:55:20.106893,2018-08-13T14:41:10.245107 | |
| v2j97,"A Comprehensive Analysis of Security Issues and Cryptographic Paradigms in Wireless Ad hoc Sensor Networks","The proliferation of Ad hoc sensor networks in various application scenarios has ostensibly called for effective security mechanisms. A lot of effort has been put and research has been carried out to tackle various threats that breach the security goals of the network. Since Wireless Sensor Network (WSN) does not rely on a concrete infrastructure and often deployed in hostile and irregular environments, its security requirement also differs vastly with that of traditional networks. It, thus, becomes imperative to design cryptographic algorithms that works efficiently keeping in mind the inherent limitations and constraints on resources, computational capability. In this paper, we present a survey on various security challenges of WSN and mechanisms to tackle the same. The aim is to present an extensive literature upon which research on security in WSN can be carried out.",1,https://api.osf.io/v2/files/5b69b1b4fed49e001b762e7a/,258,https://engrxiv.org/v2j97/,10.31224/osf.io/v2j97,,2018-08-07T14:53:20.763732,2019-04-14T06:13:41.510049 | |
| jyt96,"A Note on Fourier Transform Conventions Used in Wave Analyses","Temporal and spatial Fourier transforms are natural tools in the study of propagating waves in many applications. For example, the inverse spatial Fourier transform specifies how any wave can be built by summing plane waves. However, sign conventions necessary to describe waves are at odds with sign conventions used in spatio-temporal Fourier transforms. This note describes the problem and shows several ways that authors deal with it.",1,https://api.osf.io/v2/files/5b5ed86eecdfe0000e82383b/,278,https://engrxiv.org/jyt96/,10.31224/osf.io/jyt96,,2018-07-30T09:27:07.503568,2019-07-16T09:27:56.498655 | |
| m6d2j,"Co/TiO2 nanoparticles: preparation, characterization and its application for photocatalytic degradation of methylene blue","In this work, TiO2 nanoparticles containing different amounts of cobalt were synthesized by sol-gel method using titanium (IV) isopropoxide and cobalt chloride as titanium and cobalt precursors, respectively. X-ray diffraction (XRD) results showed prepared samples include 100% anatase phase. The presence of cobalt in TiO2 nanoparticle network was established by XRD, scanning electron microscopy equipped with energy dispersive X-ray microanalysis (SEM-EDX), Fourier transform infrared (FT-IR) and N2 physisorption techniques. The increase of cobalt doping enhanced redshif in the diffuse reflectance spectra. The photocatalytic activity of the prepared samples was tested for degradation of methylene blue (MB) as a model of dye. Although the photocatalytic activity of pure TiO2 was found to be higher than that of Co/TiO2 samples under UV irradiation, the presence of 0.24% cobalt dopant in TiO2 nanoparticles resulted in a photocatalyst with the highest activity under visible light",1,https://api.osf.io/v2/files/5b5e92cff63e21000fed104e/,472,https://engrxiv.org/m6d2j/,10.31224/osf.io/m6d2j,10.5004/dwt.2017.20205,2018-07-30T04:47:07.885000,2018-07-30T15:08:55.745996 | |
| bhjv4,"Electrospray characteristics of aqueous KCl solutions with various electrical conductivities","In the present experimental study, the effects of electrical conductivity on electrospraying procedure are investigated. | |
| A metallic nozzle with 600 m ID as high voltage electrode and a stainless steel ring as a ground | |
| electrode were employed. Experiments were carried out in still room temperature. Four different aqueous KCl | |
| solutions were sprayed in various high voltages and flow rates. Results confirm that spraying modes changes | |
| with conductivity variation. For forming a cone shape, emerging from the nozzle, required applied electric field | |
| decreases with conductivity increasing. Results also revealed that conductivity of dispersed solution acts a main | |
| role on forming and elongation of the cones in electrospraying procedure. The size and velocity of emanated | |
| droplets are also investigated in order to gaining some insight to the electrospraying phenomenon.",1,https://api.osf.io/v2/files/5b5e86dfecdfe0001081dbe7/,252,https://engrxiv.org/bhjv4/,10.31224/osf.io/bhjv4,,2018-07-30T03:43:42.939265,2018-07-30T14:50:21.775130 | |
| 3wnbv,"Analyze engine friction in view of the new WLTC driving cycle","With increasingly strict legislation and further the introduction of a new testing procedure WLTP, the highly detailed knowledge of engine friction becomes essential to obtain further fuel economy reductions. In the following, a novel engine friction testing method is used together with a highly accurate simulation to analyze engine friction exemplary for the Renault Energy dCi 130 Diesel engine in great detail and discuss the results in view of the upcoming new testing procedure.",1,https://api.osf.io/v2/files/5b5841b2195a1a000ecf47f4/,296,https://engrxiv.org/3wnbv/,10.31224/osf.io/3wnbv,10.1007/s35146-017-0139-3,2018-07-25T09:32:20.410236,2018-07-25T23:28:29.227278 | |
| 4rqxc,"Ultrashort-Pulsed Laser Machining of Dental Ceramic Implants","A novel approach for machining of cylindrical hard materials and arbitrary shapes is presented. Alumina-toughened zirconia dental implants with complex geometry are manufactured with femtosecond quasi-tangential laser ablation. This rapid-prototyping approach for small-scale production decreases the development-time cycle tremendously and trumps conventional approaches. Moreover, a competitive parameter study for radial and tangential ablation with single and multi-pulse is presented. A process achieving an ablation rate of 1mm3/min with a surface roughness Ra of 0.2 µm is introduced. The meta-stable tetragonal phase of the ceramic persists and is assessed via Raman spectroscopy. The small heat-affected zone is subsequently ablated with a radial laser process step. Hence, high-precision dental implants with a mean error of smaller 5 µm over the complete contour are shown.",1,https://api.osf.io/v2/files/5b520e8469e43a000fd22d53/,492,https://engrxiv.org/4rqxc/,10.31224/osf.io/4rqxc,10.1016/j.jeurceramsoc.2018.11.007,2018-07-20T16:37:16.887987,2019-01-06T23:58:01.582831 | |
| gkhtq,"Path Calculation of 7-axes Synchronous Quasi-Tangential Laser Manufacturing","Quasi-tangential laser processing, also called laser turning is increasingly applied for various applications. Specifically, its ability to generate complex geometries with small feature sizes at high precision and surface quality in hard, brittle and electrically non-conductive materials. Due to the geometric flexibility, the process is well suited for prototyping in hard-to-machine materials such as ceramics, carbides and super-abrasives. However, the lack of advanced software solutions for this novel process hitherto limited the exploitation of the potential. Here, we discuss a unique computer aided manufacturing approach for synchronous 7-axis laser manufacturing with quasi-tangential strategies. This gives the peerless possibility to process arbitrary geometries, which cannot be manufactured with conventional techniques. A detailed description of the path calculation with derivation and procedures is given. The generated machine code is tested on a 7-axis laser manufacturing setup. Following, a processed cylindrical ceramic specimen with a continuously varying profile along a helical path is presented. The profile is constituted by a rectangular over half-spherical to a triangular groove with defined pitch, which provides the validation of this CAM solution. Measurements of the produced specimen show high adherence with the target geometry with an average deviation below 10 µm.",1,https://api.osf.io/v2/files/5b520827c86a8c000f431c34/,388,https://engrxiv.org/gkhtq/,10.31224/osf.io/gkhtq,10.1007/s00170-019-03540-5,2018-07-20T16:28:48.258946,2019-04-03T16:35:08.029636 | |
| gxkmw,"Asynchronous Early Output Dual-Bit Full Adder with Reduced Area","This technical note presents the design of a new area optimized asynchronous early output dual-bit full adder (DBFA). An asynchronous ripple carry adder (RCA) is constructed based on the new asynchronous DBFAs and existing asynchronous early output single-bit full adders (SBFAs). The asynchronous DBFAs and SBFAs incorporate redundant logic and are encoded using the delay-insensitive dual-rail code (i.e. homogeneous data encoding) and follow a 4-phase return-to-zero handshaking. Compared to the previous asynchronous RCAs involving DBFAs and SBFAs, which are based on homogeneous or heterogeneous delay-insensitive data encodings and which correspond to different timing models, the early output asynchronous RCA incorporating the proposed DBFAs and/or SBFAs is found to result in reduced area for the dual-operand addition operation and feature significantly less latency than the asynchronous RCAs which consist of only SBFAs. The proposed asynchronous DBFA requires 28.6% less silicon than the previously reported asynchronous DBFA. For a 32-bit asynchronous RCA, utilizing 2 stages of SBFAs in the least significant positions and 15 stages of DBFAs in the more significant positions leads to optimization in the latency. The new early output 32-bit asynchronous RCA containing DBFAs and SBFAs reports the following optimizations in design metrics over its counterparts: i) 18.8% reduction in area than a previously reported 32-bit early output asynchronous RCA which also has 15 stages of DBFAs and 2 stages of SBFAs, ii) 29.4% reduction in latency than a 32-bit early output asynchronous RCA containing only SBFAs.",1,https://api.osf.io/v2/files/5b5164a9c86a8c000f428101/,221,https://engrxiv.org/gxkmw/,10.31224/osf.io/gxkmw,,2018-07-20T04:29:31.440151,2018-08-08T05:36:02.895954 | |
| js6pr,"TAXONOMY OF THE INDUSTRY 4.0: THEORETICAL AND PRACTICAL CONTRIBUTIONS TO A NEW CONTEXT","Understanding Industry 4.0 is to assimilate the elements that comprise it and to understand the processes necessary to implement it. The objective of this study was to perform a taxonomy regarding the theme industry 4.0, presenting the main contributions, obstacles and perspective regarding the theme. To reach this goal, this study began with a systematic review through the Theory of the Consolidated Meta-Analytic Approach, presenting the main scientific contributions and key factors of success. In the second part, an interview was conducted, with six researchers in the field of industry 4.0, to discuss the results of the scientific literature. There were nine key factors to the success of industry 4.0 (Cyber-Physical Systems (CPS), Internet of Things (IOT), Additive Manufacturing, Digital Manufacture (Simulation), Smart Factory, Big Data and Analytics, Cloud Computing, Digital Security and Advanced Robotics) and the major obstacles to implementing these factors. In addition, the opinions of the specialists were evaluated and categorized them by descending hierarchical classification and confirmatory factorial analysis, offering a practical model of implementation.",1,https://api.osf.io/v2/files/5b513d8469e43a000fd16b5f/,487,https://engrxiv.org/js6pr/,10.31224/osf.io/js6pr,,2018-07-20T01:45:08.549393,2018-07-20T13:49:46.054876 | |
| 8d9w5,"High-throughput preprocessing pipeline for resting-state fMRI","Resting-state functional magnetic resonance imaging (fMRI) examines functional connectivity between brain regions by measuring spontaneous fluctuation of blood-oxygen-level dependent (BOLD) signal while subjects are at rest. Recent studies have revealed that neurodegenerative diseases are associated with abnormalities in resting-state functional connectivity. This thesis work aimed to develop a high-throughput preprocessing pipeline for minimizing spatial and temporal artifacts in resting-state fMRI data. The building blocks and cluster computing capabilities of the pipeline are discussed in detail. In an effort to validate this pipeline, a seed-based analysis was performed on preprocessed data using 3 seeds placed in the posterior cingulate cortex (PCC), supplementary motor area (SMA) and inferior parietal sulcus (IPS). These 3 seeds represent the core components of the default mode network (DMN) and task-positive network (TPN), two of the most commonly examined resting-state networks. Consistent with literature, results indicate that activity in the PCC is functionally correlated to regions of the DMN and anti-correlated to regions of the TPN, whereas activities in the SMA and IPS are functionally correlated to regions of the TPN and anti-correlated to regions of the DMN. These functional connectivity patterns were consistent across scans on both group-level and subject-level. This preprocessing pipeline will support researchers and clinical collaborators of Medical Image Analysis Lab (MIAL) in their analysis of resting-state functional connectivity.",1,https://api.osf.io/v2/files/5b50bdf41ce7450013dc6f3f/,394,https://engrxiv.org/8d9w5/,10.31224/osf.io/8d9w5,,2018-07-19T16:45:14.724992,2018-07-19T19:13:58.639251 | |
| s43gr,"Compatibility of wind and solar energy with electricity demand in Argentina","One of the greatest obstacles in the exploitation of wind and solar resources is the uncertainty in their availability, usually known as intermittency effects. These effects can be greatly diminished by combining wind and solar resources from different locations. In this article we study the temporal variability of solar irradiance and wind speeds in Argentina, focusing on current projects and those included in GENREN and RENOVAR tenders. We also converted two year wind speeds and irradiance time series into power production, analyzing its compatibility with demand. Finally we numerically search the best distribution of additional capacity that minimizes a basic measure of the intermittency effect.",1,https://api.osf.io/v2/files/5b4f68c033f0b9000fbaa64d/,313,https://engrxiv.org/s43gr/,10.31224/osf.io/s43gr,,2018-07-18T16:26:21.033454,2018-07-18T19:32:01.715989 | |
| cdvy9,"Analytical Cost Modeling for Co-Located Wind-Wave Energy Arrays","Offshore wind and wave energy are co-located resources, and both the offshore wind and wave energy industries are driven to reduce costs while maintaining or increasing power production within developments. Due to the maturity of offshore wind technology and continued growth of both offshore floating wind and wave energy converter (WEC) technology, there is new opportunity within the offshore renewable energy sector to combine wind and wave technologies in the same leased ocean space through co-located array development. Combining wind and wave energy technologies through co-location is projected to have synergistic effects that reduce direct and indirect costs for developments. While several of these effects have been quantified, many have not been related to cost, and there is currently no cost model that incorporates all of these effects. Further, in areas where fixed-bottom offshore wind structures are infeasible, floating offshore wind platforms could provide access to plentiful resource further offshore. In this paper, we develop a cost model that represents co-located array developments, particularly for floating offshore wind and wave energy converter technology, and identify research gaps and uncertainties to be minimized in future work.",1,https://api.osf.io/v2/files/5b4e6a586d4eb300136e59f3/,290,https://engrxiv.org/cdvy9/,10.31224/osf.io/cdvy9,,2018-07-17T22:22:39.942964,2018-07-18T15:22:42.423954 | |
| w9fcm,"A Hybrid Fuzzy System Based Cooperative Scalable and Secured Localization Scheme For Wireless Sensor Networks","Localization entails position estimation of sensor nodes by employing different techniques and mathematical computations. Localizable sensors also form an inherent part in the functioning of IoT devices and robotics. In this article, the author extends1 a novel scheme for node localization implemented using a hybrid fuzzy logic system to trace the node locations inside the deployment region, presented by the Abhishek Kumar et. al. The results obtained were then optimized using Gauss Newton Optimization to improve the localization accuracy by 50% to 90% vis-à-vis weighted centroid and other fuzzy based localization algorithms. This article attempts to scale the proposed scheme for large number of sensor nodes to emulate somewhat real world scenario by introducing cooperative localization in previous presented work. The study also analyses the effectiveness of such scaling by comparing the localization accuracy. In next section, the article incorporates security in the proposed cooperative localization approach to detect malicious nodes/anchors by mutual authentication using El Gamel digital Signature scheme. A detailed study of the impact of incorporating security and scaling on average processing time and localization coverage has also been performed. The processing time increased by a factor of 2.5s for 500 nodes (can be attributed to more number of iterations and computations and large deployment area with small radio range of nodes) and coverage remained almost equal, albeit slightly low by a factor of 1% to 2%. Apart from these, the article also discusses the impact of adding extra functionalities in the proposed hybrid fuzzy system based localization scheme on processing time and localization accuracy. Lastly, this study also briefs about how the proposed scalable, cooperative and secure localization scheme tackles the type of attacks that pose threat to localization.",1,https://api.osf.io/v2/files/5b4d63681e450900114c4a8e/,303,https://engrxiv.org/w9fcm/,10.31224/osf.io/w9fcm,10.5121/ijwmn.2018.10305,2018-07-17T03:37:15.653808,2019-04-01T15:54:15.163032 | |
| puw4q,"LEVELIZED COST OF ENERGY (LCOE) ANALYSIS OF HEXCRETE WIND TOWERS","Wind power generation has witnessed a dramatic growth in the 21st century. The Department of Energy (DOE) had a vision for wind energy that it would change into an extensively greater part of overall power generation in the U.S. by 2050. As specified by the DOE, wind power generation has grown by trifold from 2008 to 2013. This study presents a constructible, financially feasible alternative wind tower design to the 80 m steel tower platform which has the potential to decrease the overall Levelized cost of energy (LCOE). A hexagonal concrete wind tower solution is evaluated to facilitate the fabrication of a taller wind turbine generator to harvest more powerful, stable, and frequent wind resources for elevating wind energy production to cut down the overall LCOE. Subject matter experts from the industry were benefitted from to develop a process and estimate the cost and schedule of development and assembly of this process. To mitigate uncertainties and quantify risks, a sensitivity analysis was carried out on cost and schedule estimates. Also, estimating LCOE of wind towers is a primary requirement for efficient assimilation of wind power generation in the electricity market. In the state of Iowa, wind power is rapidly becoming a significant electricity generator. Unpredictable outputs and different options for deploying wind towers are one of the major problems of power system operators. Good estimation tools are important and will be needed to integrate wind energy into the economic power plant. The other objective of this research is to propose a GIS-based map to visualize LCOE of different wind tower construction options in various locations. Therefore, wind speed GIS mapping by using weather information will be crucial. Calculation of energy output by applying wind gradient formula to wind speeds energy are performed. The research concludes of Hexcrete towers can be achieved by use of the 120m and 140 m Hexcrete tower platform on certain wind sites in the United States.",1,https://api.osf.io/v2/files/5b4cce0525fdcd0010e62dc9/,274,https://engrxiv.org/puw4q/,10.31224/osf.io/puw4q,10.13140/RG.2.2.36643.35367/1,2018-07-16T17:01:40.919704,2018-07-16T17:40:34.896867 | |
| 2dx5e,"Embedded finite elements for modeling axonal injury","The purpose of this paper is to propose and develop a large strain embedded finite element formulation that can be used to explicitly model axonal fiber bundle tractography from diffusion tensor imaging of the brain. Once incorporated, the fibers offer the capability to monitor tract-level strains that give insight into the biomechanics of brain injury. We show that one commercial software has a volume and mass redundancy issue when including embedded axonal fiber and that a newly developed algorithm is able to correct this discrepancy. We provide a validation analysis for stress and energy to demonstrate the method.",1,https://api.osf.io/v2/files/5b49535025fdcd0011e41ec4/,406,https://engrxiv.org/2dx5e/,10.31224/osf.io/2dx5e,,2018-07-14T01:37:13.826689,2018-07-14T02:02:30.959887 | |
| 784mz,"Effect of marble powder concentration on Mechanical Properties of unsaturated polyster resin for the development of rock climbing holds","The introduction of climbing holds has given rise to indoor climbing facilities. Climbing holds arranged in the form of a route are used to simulate an artificial environment for rock climbing, often similar to that found in nature. This paper highlights the significance of material composition for the application of rock climbing hold manufacture. A particle reinforced composite material, comprising of an unsaturated polyester resin, reinforced with marble powder was developed and the effect on mechanical properties was studied with varying powder concentration , beginning from 0% reinforcement to 30%, 40%, 50% and subsequently 60 % reinforcement . Test specimens were made according to ASTM standards and were tested for tensile, izod impact strength and Rockwell hardness. Trends were established based on the results obtained. Furthermore, hardness values were also compared with commercially available climbing holds.",1,https://api.osf.io/v2/files/5b46f7bc39cb1f0011930084/,272,https://engrxiv.org/784mz/,10.31224/osf.io/784mz,,2018-07-12T06:46:53.416902,2018-07-24T16:10:42.373641 | |
| 8kne7,"Predicting Part Mass, Required Support Material, and Build Time via Autoencoded Voxel Patterns","Additive Manufacturing (AM) allows designers to create intricate geometries that were once too complex or expensive to achieve through traditional manufacturing processes. Currently, Design for Additive Manufacturing (DfAM) is restricted to experts in the field, and novices may overlook potentially transformational design potential enabled by AM. This project aims to make DfAM accessible to a broader audience through deep learning, enabling designers of all skill levels to leverage unique AM geometries when creating new designs. To demonstrate such an approach, a database of files was acquired from industry-sponsored AM challenges focused on lightweight design. These files were converted to a voxelized format, which provides more robust information for machine learning applications. Next, an autoencoder was constructed to a low-dimensional representation of the part designs. Finally, that autoencoder was used to construct a deep neural network capable of predicting various DfAM attributes. This work demonstrates a novel foray towards a more extensive DfAM support system that supports designers at all experience levels.",1,https://api.osf.io/v2/files/5b3b21b9fc7cf4000f3a7984/,396,https://engrxiv.org/8kne7/,10.31224/osf.io/8kne7,,2018-07-03T07:14:34.570000,2018-07-03T19:05:39.389647 | |
| etgc8,"Optimal Design of Laboratory and Pilot-plant Experiments using Multiobjective Optimization","Performing an experimental design prior to the collection of data is in most circumstances important to ensure efficiency. The focus of this work is the combination of model‐based and statistical approaches to optimal design of experiments. The knowledge encoded in the model is used to identify the most interesting range for the experiments via a Pareto optimization of the most important conflicting objectives. Analysis of the trade‐offs found is in itself useful to design an experimental plan. This can be complemented using a factorial design in the most interesting part of the Pareto frontier.",1,https://api.osf.io/v2/files/5b338c9ad65eaa000ee28190/,245,https://engrxiv.org/etgc8/,10.31224/osf.io/etgc8,10.1002/cite.201600104/full,2018-06-28T07:17:13.739984,2018-07-02T11:57:50.954090 | |
| kyv89,"Relay Channel with Non-causal State Information at the Source and Relay","A state-dependent discrete memoryless relay channel is considered, with non-causal side information | |
| available at both the sender and the relay. The capacity of this | |
| relay model is an open problem. We improve upon the known | |
| achievable regions for this setting, in addition to proving an outer | |
| bound. The key idea in the proof of achievable region is to employ | |
| a modified decode-forward scheme. The characterization is then | |
| extended to a relay broadcast setting, where an improved inner | |
| bound over existing schemes and an outer bound are exhibited.",1,https://api.osf.io/v2/files/5b326c45d65eaa000ee1498c/,219,https://engrxiv.org/kyv89/,10.31224/osf.io/kyv89,,2018-06-26T16:42:00.364516,2018-07-02T11:57:48.192277 | |
| acvsy,"SISTEMAS REMOTOS CENTRALIZADOS: UNA SOLUCIÓN EFECTIVA PARA EL MANTENIMIENTO AERONÁUTICO","This paper describes the implementation of a remote centralized access system at Jose Maria Cordoba Airport and the maintenance personnel (ATSEP) work terminal for efficient data collection from the navigation systems (Radio aids) of the Antioquia’s branch of the Colombian Civil Aviation Authority. | |
| To implement this system several radio links were installed to transport the data to the main tower of each airport and then the information was integrated into the Aerocivil’s network through a Port Server and a Switch that are part of the implemented system.",1,https://api.osf.io/v2/files/5b325cd1d65eaa000fde6949/,197,https://engrxiv.org/acvsy/,10.31224/osf.io/acvsy,,2018-06-26T15:47:24.806850,2018-07-02T11:57:47.814086 | |
| 86ptk,"METODOLOGIA PARA ESTIMAR EL POTENCIAL ENERGETICO EN LAS ESTACIONES AERONAUTICAS DE LA AERONAUTICA CIVIL DE COLOMBIA","The following document contains the methodology for estimating the solar energy potential in each of the location zones of the aeronautical stations in Colombia; for Communications, Navigation and Surveillance services. It includes information on the infrastructure of the country's aeronautical stations and their different sources of support. Resumen El siguiente documento contiene la metodológia para la estimación del potencial energético solar en cada una de las zonas de ubicación de las estaciones aeronáuticas en Colombia; para los servicios de Comunicaciones, Navegación y Vigilancia. Contempla información de la infraestructura de las estaciones aeronáuticas del país y sus diferentes fuentes de respaldo.",1,https://api.osf.io/v2/files/5b318389d65eaa000ee02af9/,242,https://engrxiv.org/86ptk/,10.31224/osf.io/86ptk,,2018-06-26T00:24:25.613871,2018-07-02T11:57:46.575076 | |
| bmu8z,"The effects of turbulent flow on wind turbine performance evaluation","Most of the world's wind turbines operate under various turbulent wind conditions. Turbulent wind is a big source of uncertainty, and could cause, if unaddressed, significant variation from a turbine's calculated efficiency and even its destruction. | |
| Turbulent flow in wind turbines has a profound effect on various aspects including structural load, estimation of a site's energy potential, calculated efficiency, and many more. However, even though significant advances have been made in the field of anemometry the subjects of estimating a wind turbine's site energy potential and analyzing a turbine's efficiency has not been updated. | |
| In this work high frequency wind measurements that included wind speed using two different anemometers, wind direction and others were gathered and analyzed. The energy potential and efficiency of the turbine was calculated using this data and compared to the figures that would have been received by using the methods described in the IEC 61400-12-2 Standard. | |
| Results show that by using a higher frequency measuring system both a site's energy potential and turbine's efficiency can vary substantially in comparison with the methods described in the International Standard. | |
| This research can affect the way a future wind turbine's site energy potential is measured, it can cause existing wind turbine to reevaluate their productivity performance, and on top of all it can cause the examination of the validity of the International Standards regarding wind turbine performance: IEC 61400-12-1 and IEC 61400-12-2.",1,https://api.osf.io/v2/files/5b2fc122d65eaa000edd8459/,218,https://engrxiv.org/bmu8z/,10.31224/osf.io/bmu8z,,2018-06-24T19:41:47.181580,2018-07-02T11:57:44.058031 | |
| fnwjy,"Deep Learning of Vortex Induced Vibrations","Vortex induced vibrations of bluff bodies occur when the vortex shedding frequency is close to the natural frequency of the structure. Of interest is the prediction of the lift and drag forces on the structure given some limited and scattered information on the velocity field. This is an inverse problem that is not straightforward to solve using standard computational fluid dynamics (CFD) methods, especially since no information is provided for the pressure. An even greater challenge is to infer the lift and drag forces given some dye or smoke visualizations of the flow field. Here we employ deep neural networks that are extended to encode the incompressible Navier-Stokes equations coupled with the structure's dynamic motion equation. In the first case, given scattered data in space-time on the the velocity field and the structure's motion, we use four coupled deep neural networks to infer very accurately the structural parameters, the entire time-dependent pressure field (with no prior training data), and reconstruct the velocity vector field and the structure's dynamic motion. In the second case, given scattered data in space-time on a concentration field only, we use five coupled deep neural networks to infer very accurately the vector velocity field and all other quantities of interest as before. This new paradigm of inference in fluid mechanics for coupled multi-physics problems is part of our ongoing development of physics-informed learning machines, where the traditional CFD methodology is abandoned in favor of deep neural networks inference, circumventing the tyranny of elaborate mesh generation.",1,https://api.osf.io/v2/files/5b2f2690daf8210013d4bceb/,801,https://engrxiv.org/fnwjy/,10.31224/osf.io/fnwjy,,2018-06-24T05:19:19.619436,2018-07-02T11:57:43.836232 | |
| 2845a,"Development and validation of a meshless 3D material point method for simulating the micro-milling process","A meshless Generalized Interpolation Material Point Method for simulating the micro-milling process was developed. This method has several advantages over well-established approaches (such as finite elements) when it comes to large plastic strains and deformations, since it inherently does not suffer from tensile | |
| instability problems. The feasibility of the developed material point model for simulating micro-milling is verified against finite element simulations and experimental data. The model is able to successfully predict experimentally measured cutting forces and determine chip temperatures in agreement with conventional finite element simulations. After having verified the approach, the model was applied to perform extensive numerical 3D simulations of the micro-milling process. The goal is to evaluate the response of the micro-milling cutting forces as function of the hardening behavior of the micro-milled material. The meshless 3D simulations reveal a dependency of tool force slopes (with respect to the uncut chip thickness) on the hard-ening parameters. Based on these findings, a new approach is outlined to determine hardening parameters | |
| directly from two micro-milling experiments with distinct, sufficiently large uncut chip thicknesses.",1,https://api.osf.io/v2/files/5b2bba68d76a3f0010f0800d/,303,https://engrxiv.org/2845a/,10.31224/osf.io/2845a,,2018-06-21T15:09:48.634882,2018-07-02T11:56:47.780071 | |
| 9gkxe,"Design Practica as Authentic Assessments in First-year Engineering Design Courses","This paper describes the design and evaluation of a novel assessment for first-year engineering design courses that is rooted in an authentic design challenge. This approach modifies the traditional written-exam approach typically found in engineering courses, which is inherently inauthentic and cannot easily capture the exploratory nature of engineering design. Our assessment improves alignment with common learning objectives found in first-year engineering design courses and additionally prepares students for the type of case study interviews that are increasingly common for entry-level engineering jobs. To evaluate our assessment, 50 first-year students completed the engineering design self-efficacy instrument once before beginning the assessment and a second time approximately 48 hours later upon completion of a reflection assignment. In addition, students retrospectively reported their perceived change in self-efficacy during the assessment. Analysis shows that students perceived a large retrospective increase in skill level, despite only a small increase in directly measured self-efficacy. These results are analyzed in light of the Dunning-Kruger effect and we posit that the assessment helps to align students’ self-efficacy with their actual skill level. Increased alignment of self-efficacy with skill level may minimize student frustration when encountering challenging tasks in the future, potentially increasing retention of engineering students as well as facilitating the development of lifelong learning attitudes.",1,https://api.osf.io/v2/files/5b23eb0f8b4bed0010b5625a/,243,https://engrxiv.org/9gkxe/,10.31224/osf.io/9gkxe,,2018-06-15T16:38:12.958917,2018-07-02T11:56:43.086049 | |
| 8b73v,"""Thus, I had to go with what I had"": A Multiple Methods Exploration of Novice Designers' Articulation of Prototyping Decisions","Effectively communicating designs to stakeholders or end users is a critical step in the design process yet can be a difficult challenge for engineers. Prototypes are unique tools that can enhance communication between these two groups, as prototypes are physical manifestations of the designer’s mental model. Previous work has demonstrated that novice designers often struggle to use prototypes as communication tools. We argue that it is critical that engineering students learn to fully leverage prototypes, and thus the current work sought to understand the relationship between argumentation, prototyping, and design decisions. In order to understand the communication patterns of novice designers during a prototyping task, a controlled study was conducted with a total of 46 undergraduate engineering students. The analysis of quantitative and qualitative data point to the intricate linkages between how students make material decisions and how they justify those decisions.",1,https://api.osf.io/v2/files/5b225a3bccac7900123537e3/,253,https://engrxiv.org/8b73v/,10.31224/osf.io/8b73v,10.1115/DETC2018-85800,2018-06-14T12:08:45.331137,2018-07-02T11:56:42.103188 | |
| e8awk,"Energy and Water Consumption Characterization of Portuguese Indoor Swimming Pools","Indoor swimming pools have high water and energy (electricity and natural gas) consumption levels due to the need to provide suitable thermal comfort conditions (temperature and relative humidity) to its occupants and to counterbalance losses (evaporation, ventilation, etc.). In Portugal, most of the swimming pool facilities belong to the municipalities and their operation represent a considerable financial burden. This work intent to characterize and benchmark the energy (electrical and thermal) and water consumption of five sport complexes with indoor swimming pools, located in two cities of the Centre of Portugal. The four most commonly performance indicators used in the literature were calculated and analyzed according to the operating time and services. Some measures are suggested to enhance the energy efficiency as well as to reduce the consumptions.",1,https://api.osf.io/v2/files/5b225827ccac790011353ff8/,464,https://engrxiv.org/e8awk/,10.31224/osf.io/e8awk,,2018-06-14T12:05:10.272564,2018-07-02T11:56:41.829400 | |
| ucn3y,"Autonomy: Science and Systems, TEAM-B, Final Project Report","The interest and need for autonomy in vehicles in growing. A larger number of automobile manufacturers are looking for people with a different set of skills than was traditionally expected from an Automotive engineer. Through the course of this project, we gained a basic introduction into what it takes to make an autonomous car and successfully built an autonomous mobile robot of our own.",1,https://api.osf.io/v2/files/5b1d8a99ec24e20013b6e00d/,601,https://engrxiv.org/ucn3y/,10.31224/osf.io/ucn3y,,2018-06-10T20:37:22.731155,2018-07-02T11:55:47.395755 | |
| cp8zk,"Autonomy Science and Systems Project Report","With the increase in automation and the advancement of robotic technologies, comes an increasing | |
| push to incorporate automation into the development of self-driving vehicles. Many companies have | |
| developed initiatives devoting resources to increasing the application of automation sciences to automotive technologies. The Autonomy Sciences and Systems course was offered on the Spring of 2017. This course engaged | |
| students into a survey of state-of-the art robotics algorithms found in research while introducing tools | |
| used to develop these technologies. The robotic operating system (ROS) was the main programming environment used to perform many of the course activities as well as the final project. This is a report documenting Team A's implementation of the final project with associated instructions and tutorials.",1,https://api.osf.io/v2/files/5b1d7ecfb796ba000e42694b/,204,https://engrxiv.org/cp8zk/,10.31224/osf.io/cp8zk,,2018-06-10T20:25:44.215091,2018-07-02T11:55:47.362983 | |
| 68bvh,F1_Tenth_Course_Report_Group_C,"In this paper, we discuss several of major robot/vehicle platforms available and demonstrate the implementation of autonomous techniques on one such platform, the F1/10. Robot Operating System was chosen for its existing collection of software tools, libraries, and simulation environment. We build on the available information for the F1/10 vehicle and illustrate key tools that will help achieve properly functioning hardware. We provide methods to build algorithms and give examples of deploying these algorithms to complete autonomous driving tasks and build 2D maps using SLAM. Finally, we discuss the results of our findings and how they can be improved.",1,https://api.osf.io/v2/files/5b1c9e2fec24e20011b6b59a/,306,https://engrxiv.org/68bvh/,10.31224/osf.io/68bvh,,2018-06-10T03:48:12.121144,2018-07-02T11:55:46.899766 | |
| q75n6,"Data on the Configuration Design of Internet-Connected Home Cooling Systems by Engineering Students","This experiment was carried out to record the step-by-step actions that humans take in solving a configuration design problem, either in small teams or individually. Specifically, study participants were tasked with configuring an internet-connected system of products to maintain temperature within a home, subject to cost constraints. Every participant was given access to a computer-based design interface that allowed them to construct and assess solutions. The interface was also used to record the data that is presented here. In total, data was collected for 68 participants, and each participant was allowed to perform 50 design actions in solving the configuration design problem. Major results based on the data presented here have been reported separately, including initial behavioral analysis and design pattern assessments via Markovian modeling.",1,https://api.osf.io/v2/files/5b1945f7b796ba000f3df9c0/,223,https://engrxiv.org/q75n6/,10.31224/osf.io/q75n6,10.1016/j.dib.2017.08.050,2018-06-07T14:51:30.871216,2018-07-02T11:54:49.565701 | |
| 847je,"A Two-Tiered Grammatical Approach for Agent-based Computational Design","Early stages of the engineering design process are vital to shaping the final design; each subsequent step builds from the initial concept. Innovation-driven engineering problems require designers to focus heavily on early-stage design generation, with constant application and evaluation of design changes. Strategies to reduce the amount of time and effort designers spend in this phase could improve the efficiency of the design process as a whole. This paper seeks to create and demonstrate a two-tiered design grammar that encodes heuristic strategies to aid in the generation of early solution concepts. Specifically, this two-tiered grammar mimics the combination of heuristic-based strategic actions and parametric modifications employed by human designers. Rules in the higher-tier are abstract and potentially applicable to multiple design problems across a number of fields. These abstract rules are translated into a series of lower-tier rule applications in a spatial design grammar, which are inherently domain-specific. This grammar is implemented within the HSAT agent-based algorithm. Agents iteratively select actions from either the higher-tier or lower-tier. This algorithm is applied to the design of wave energy converters, devices which use the motion of ocean waves to generate electrical power. Comparisons are made between designs generated using only lower-tier rules and those generated using only higher-tier rules.",1,https://api.osf.io/v2/files/5b184c39ec24e20012b3739c/,265,https://engrxiv.org/847je/,10.31224/osf.io/847je,10.1115/DETC2018-85648,2018-06-06T21:05:39.523449,2018-07-02T11:54:48.303501 | |
| jbw7y,"Design Strategy Transfer in Cognitively-Inspired Agents","Planning and strategizing are essential parts of the design process and are based on the designer’s skill. Further, planning | |
| is an abstract skill that can be transferred between similar problems. However, planning and strategy transfer within design have not been effectively modeled within computational agents. This paper presents an approach to represent this strategizing behavior using a probabilistic model. This model is employed to select the operations that computational agents should perform while solving configuration design tasks. This work also demonstrates that this probabilistic model can be used to transfer strategies from human data to computational agents ina way that is general and useful. This study shows a successful • transfer of design strategy from human-to-computer agents, opening up the possibility of deriving high-performing behavior from designers and using it to guide computational design agents. Finally, a quintessential behavior of transfer learning is illustrated by agents while transferring design strategies across different problems, improving agent performance significantly. The work presented in this study leverages a computational framework built by embedding cognitive characteristics into agents, which has shown to mimic human problem-solving in configuration design problems.",1,https://api.osf.io/v2/files/5b183db9f37a71000e3ed4ba/,265,https://engrxiv.org/jbw7y/,10.31224/osf.io/jbw7y,10.1115/DETC2018-85599,2018-06-06T20:04:38.461789,2018-07-02T11:54:48.070784 | |
| 28sng,"Quantification of Alveolar Recruitment for the Optimization of Mechanical Ventilation Using Quasi-Static Pressure Volume Curve","Quasi-static, pulmonary pressure-volume (P-V) curves over an inflation-deflation cycle are analyzed using a respiratory system model (RSM), which had been developed for quantitative characterization of the mechanical behavior of the total respiratory system. Optimum mechanical ventilation setting of Positive End Expiratory Pressure (PEEP) for total alveolar recruitment is quantified based on the existing P-V curves of healthy and injured animal models. Our analytical predictions may contribute to the optimization of mechanical ventilation settings for the Acute Respiratory Distress Syndrome (ARDS) patients.",1,https://api.osf.io/v2/files/5b15f9a3eca4a80010bcbbde/,206,https://engrxiv.org/28sng/,10.31224/osf.io/28sng,,2018-06-05T02:53:04.613352,2018-07-02T11:54:44.541445 | |
| 2qey3,"Ampli: A Construction Set for Paperfluidic Systems","The design and fabrication of reconfigurable, modular paperfluidics driven by a prefabricated reusable block library, asynchronous modular paperfluidic linear instrument-free (Ampli) block, are reported. The blocks are inspired by the plug-and-play modularity of electronic breadboards that lower prototyping barriers in circuit design. The resulting biochemical breadboard is a paperfluidic construction set that can be functionalized with chemical, biological, and electrical elements. Ampli blocks can form standard paperfluidic devices without any external instrumentation. Furthermore, their modular nature enhances fluidics in ways that fixed devices cannot. The blocks' ability to start, stop, modify, and reverse reaction flows, reagents, and rates in real time is demonstrated. These enhancements allow users to increase colorimetric signals, fine tune reaction times, and counter check multiplexed diagnostics for false positives or negatives. The modular construction demonstrates that field-ready, distributed fabrication of paper analytical systems can be standardized without requiring the “black box” of craft and technique inherent in paper-based systems. Ampli assembly and point-of-care redesign extends the usability of paper analytical systems and invites user-driven prototyping beyond the lab setting demonstrating “Design for Hack” in diagnostics.",1,https://api.osf.io/v2/files/5b0d8fa7ffe6a200101f0858/,359,https://engrxiv.org/2qey3/,10.31224/osf.io/2qey3,10.1002/adhm.201800104,2018-05-29T17:48:56.080158,2018-07-02T11:53:42.109206 | |
| g4qz5,"Estimating the global warming emissions of the LCAXVII conference: connecting flights matter.","Conferences are an important element of scientific activity but also one of the major causes of environmental burden. In this conference report, we analyse the carbon footprint of the annual conference of the American Center for Life Cycle Assessment, as well as some of the potential ways to reduce it. The average emissions per participant are estimated to be 952 kg CO2eq, but with a large variability due to differences in travelled distance. Results indicate that studies should use distance-dependent flight emissions to increase the accuracy of the assessment. Connection flights are found to increase emissions up to 32 % compared with direct flights, due to the increased number of take-offs and landings. A method to calculate the ideal location is proposed, which can be used to identify unreasonably distant conference locations. Some of the measures taken to reduce the impact, such as meat-free menus, had a relatively minor contribution to emissions reductions, but could be important, as scientist advocating for the reduction of environmental burden should lead by example.",1,https://api.osf.io/v2/files/5b0c7f1dfebe5e0016a38ff8/,257,https://engrxiv.org/g4qz5/,10.31224/osf.io/g4qz5,10.1007/s11367-018-1479-z,2018-05-28T22:23:07.304682,2018-07-02T13:33:17.474240 | |
| zqcf3,"Studying Human Design Teams through Computational Teams of Simulated Annealing Agents","Novel design methodologies are often evaluated through empirical studies involving human designers. However, such empirical studies can incur a high personnel cost. Further, it can be difficult to isolate the effects of specific team or individual characteristics. These limitations could be bypassed by employing a computational model of design teams. This work introduces the Cognitively-Inspired Simulated Annealing Teams (CISAT) modeling framework, an agent-based platform that provides a means for efficiently simulating human design teams. A number of empirically demonstrated cognitive phenomena are modeled within the platform, striking a balance between model simplicity and direct applicability to engineering design problems. This paper discusses the composition of the CISAT modeling framework and demonstrates how it can be used to simulate the performance of human design teams in a cognitive study. Results simulated with CISAT are compared directly to the results derived from human designers. Finally, the CISAT model is also used to investigate the characteristics that were most and least helpful to teams during the cognitive study.",1,https://api.osf.io/v2/files/5b0677d9c704aa0010d15ed3/,219,https://engrxiv.org/zqcf3/,10.31224/osf.io/zqcf3,10.1115/DETC2015-46545,2018-05-24T08:30:52.144608,2018-07-02T13:33:10.783045 | |
| wqut5,"Quantitative Comparison of High- and Low-Performing Teams in a Design Task Subject to Drastic Changes","Many design tasks are subject to changes in goals or constraints. For instance, a client might modify specifications after design has commenced, or a competitor may introduce a new technology or feature. A design team often cannot anticipate such changes, yet they pose a considerable challenge. This paper presents a study where engineering teams sought to solve a design task that was subject to two large, unexpected changes in problem formulation that occurred during problem solving. Continuous design data was collected to observe how the designers responded to the changes. We show that high- and low-performing teams demonstrated very different approaches to solving the problem and overcoming the changes. In particular, high-performing teams achieved simple designs and extensively explored small portions of the design space; low-performing teams explored complex designs with little exploration around a target area of the design space. These strategic differences are interpreted with respect to cognitive load theory and goal theory. The results raise questions as to the relationship between characteristics of design problems and solution strategies. In addition, an attempt at increasing the teams’ resilience in the face of unexpected changes is introduced by encouraging early divergent search.",1,https://api.osf.io/v2/files/5b067737c704aa0011d12dbc/,232,https://engrxiv.org/wqut5/,10.31224/osf.io/wqut5,10.1115/DETC2014-34653,2018-05-24T08:27:56.879557,2018-07-02T13:33:10.743939 | |
| ap3wq,"Improving Irrigation in Remote Areas: Multi-objective Optimization of a Treadle Pump","Water-lifting technologies in rural areas of the developing world have enormous potential to stimulate agricultural and economic growth. The treadle pump, a human-powered low-cost pump designed for irrigation in developing countries, can help farmers maximize financial return on small plots of land by ending their dependency on rain-fed irrigation systems. The treadle pump uses a suction piston to draw groundwater to the surface by way of a foot-powered treadle attached to each suction piston. Current treadle pump designs lift water from depths up to 7 meters at a flow-rate of 1–5 liters per second. This work seeks to optimize the design of the Dekhi style treadle pump, which has gained significant popularity due to its simplicity. A mathematical model of the working fluid and treadle pump structure has been developed in this study. Deterministic optimization methods are then employed to maximize the flow rate of the groundwater pumped, maximize the lift height, and minimize the volume of material used for manufacturing. Design variables for the optimization included the dimensions of the pump, well depth, and speed of various parts of the system. The solutions are subject to constraints on the geometry of the system, the bending stress in the treadles, and ergonomic factors. Findings indicate that significant technical improvements can be made on the standard Dekhi design, such as increasing the size of the pump cylinders and hose, while maintaining a standard total treadle length. These improvements could allow the Dekhi pump to be implemented in new regions and benefit additional rural farmers in the developing world.",1,https://api.osf.io/v2/files/5b0675d7add54d00144e2bf4/,230,https://engrxiv.org/ap3wq/,10.31224/osf.io/ap3wq,10.1115/DETC2014-35463,2018-05-24T08:25:01.663746,2018-07-02T13:33:10.640014 | |
| 9nh7q,"Research and Practice Group Methodology: A Case Study in Student Success","Experiential learning is a key component in engineering education. In civil engineering, this component is typically delivered through multiple projects. These projects may include term projects for individual courses, senior design projects, theses, or independent studies. The focus of these experiences may gradually shift from practice-oriented projects in undergraduate studies to research-oriented projects in graduate studies. Thus, learning objectives should always address both areas with a strong emphasis on common fields, such as applied research. Experiential learning has the capacity to include various program-level outcomes, such as technical knowledge, communication and teamwork. Development of a research and practice group facilitates these outcomes by creating an environment to share the learning experience. Such a group should replicate the working environment of civil engineers by incorporating multidisciplinary projects and diverse individuals, including cross-generational members. As a case study, this work examines a Research and Practice Group at California State University Fresno. This group consists of junior and senior undergraduates, graduate students, and former members who are participating as alumni. The major focus of research within the group is resilient and sustainable structural mechanics and design. This paper outlines the methodology that has been employed to ensure academic and professional success for members of the group. This methodology incorporates a recruitment process, meetings, consultation, mentorship, networking, and support. The level of student success achieved by the group is presented in terms of the achievements of the group’s members. This includes a discussion of completed projects, research funding, and group presentations. To further demonstrate the efficacy of the methodology, students in the research group are compared to the general body of engineering students at CSU Fresno though the results of a survey. This survey is analyzed using traditional methods, as well as Latent Semantic Analysis. Our results indicate that group members are better at embodying and communicating outcomes than the rest of the student body, and that the research and practice group provides an experience that allows students to internalize and take responsibility for their own goals.",1,https://api.osf.io/v2/files/5b0674efc704aa0011d12c78/,177,https://engrxiv.org/9nh7q/,10.31224/osf.io/9nh7q,,2018-05-24T08:18:43.200530,2018-07-02T13:33:10.600744 | |
| 5yfsx,"Evaluating Wire Configurations for Tension Band Constructs using a Canine Greater Trochanteric Osteotomy Model","Objective: To investigate the stability of four tension band wiring configurations alone without the contributions of K-wire stabilization. | |
| Study design: ex vivo experimental | |
| Sample population: Sixty-four tension band wiring constructs | |
| Methods: Four tension band configurations were applied to a metal trochanteric osteotomy model based on a canine femur: figure-of-eight with one twist (OT), figure-of-eight with two twists (TT), dual interlocking single loop (DISL), and double loop (DL). Configurations were mechanically tested under both monotonic loading (n = 8 per configuration) and incremental cyclic loading (n = 8 per configuration). Initial tension after tying, residual tension remaining after each cycle, and failure load at 2 mm of displacement (considered equivalent to clinical failure) were recorded. | |
| Results: The initial tension and the load to 2 mm of displacement was lower for OT wires compared to TT wires. The DL was the strongest and most stable configuration, generating greater initial tension, maintaining a greater percentage of residual tension under incremental cyclic loads, and resisting higher load before failure at 2 mm. Failure load was highly correlated with initial tension. | |
| Conclusion: This model enabled evaluation of tension band wire configuration independent of the fixation pin portion of the construct. Wire configurations that can be tightened to a greater tension during tying, like the DL, are better able to resist the tensile loads experienced by the construct. | |
| Clinical impact: In clinical situations where high tensile loads are expected, a tighter, more secure tension band wire configuration may be warranted.",1,https://api.osf.io/v2/files/5b032b05a556d000130776bd/,333,https://engrxiv.org/5yfsx/,10.31224/osf.io/5yfsx,,2018-05-21T20:48:08.188078,2019-08-09T17:31:15.738767 | |
| w8vng,"Exploring Natural Strategies for Bio-Inspired Fault Adaptive Systems Design","Fault adaptive design seeks to find the principles and properties that enable robustness, reliability and resilience to implement those features into engineering products. In nature, this characteristic of adaptability is the fundamental trait that enables survival. Utilizing adaption strategy is a new area of research exploration for bio-inspired design. In this paper we introduce a tool for bio-inspired design for fault adaption. Further we discuss insights from using this tool in a undergraduate design experiment. The goal of the tool is to assist designers to develop fault | |
| adaptive behaviors in engineering systems using nature as inspiration. This tool is organized as a binary tree where branches that represent the specific details of how an organism achieves an adaptive behavior or characteristic. Results from an initial study indicate, for the specific challenge of designing fault adaption into a system, a strategy based method can provide designers with innovative analogies and help provide the details needed to bridge the gap between analogy and engineering implementation.",1,https://api.osf.io/v2/files/5b0321f6a556d00013076fff/,296,https://engrxiv.org/w8vng/,10.31224/osf.io/w8vng,,2018-05-21T20:10:36.243372,2018-07-02T11:53:25.827498 | |
| cft72,"A stabilising control strategy for Cyber-Physical Power Systems","The cyber-physical nature of electric power systems has increased immensely over the last decades, with advanced communication infrastructure paving the way. It is now possible to design wide-area controllers, relying on remote monitor and control of devices, that can tackle power system stability problems more effectively than local controllers. However, their performance and security relies extensively on the communication infrastructure and can make power systems vulnerable to disturbances emerging on the cyber side of the system. In this paper, we investigate the effect of communication delays on the performance and security of wide-area damping controllers (WADC) designed to stabilise oscillatory modes in a Cyber-Physical Power System (CPPS). We propose a rule-based control strategy that combines wide-area and traditional local stabilising controllers to increase the performance and maintain the security of CPPS. The proposed strategy is validated on a reduced CPPS equivalent model of Great-Britain (GB).",1,https://api.osf.io/v2/files/5b01d356e9cb34000fb1eaeb/,387,https://engrxiv.org/cft72/,10.31224/osf.io/cft72,10.1049/iet-cps.2018.5020,2018-05-20T20:13:43.491891,2019-02-18T14:32:11.358021 | |
| jg4kq,"Opportunities to Improve Academic Research Through Open Research Practices","An abstract submitted to accompany a presentation at the 2018 Polytechnic Summit, June 4--6, in Lima, Peru.",1,https://api.osf.io/v2/files/5b01d012e9cb340010b29379/,218,https://engrxiv.org/jg4kq/,10.31224/osf.io/jg4kq,,2018-05-20T19:46:25.637904,2018-07-02T11:53:23.611259 | |
| ch3vm,"Geostatistical modelling of pore pressure data: An application to Smart Markers (ENSM) in Open-Pit Mining","scription | |
| Edit | |
| For the mining industry, it is essential to know the distribution of the pore pressures exerted by the groundwater in the walls of the pit, which depends on the hydrogeological characteristics of the rock and the excavations. An inadequate management of pore pressures in open-pit mining can obstruct access to operating areas, increase the use of explosives and increase their failure, generate acid drainage and geotechnical instability in the pit itself. However, in mining practice pore pressure measurements are scarce. In order to overcome this limitation, intelligent markers (Enhanced Networked Smart Markers-ENSM) have been developed, which have pore pressure and deformation sensors coupled to pit drillings in depths of up to 200m. This network of intelligent sensors (ENSM) could provide a wealth of data never before recorded in open-pit mining operations, which allows knowing more accurately the hydrogeological conditions and anticipate the dynamics of pit deformation. In the present contribution, we propose a strategy to model the spatial continuity of the regionalized data set that will capture the intelligent markers, through a variographic analysis, to then predict the pore pressure in space and represent the variability in all spatial scales. The methodological approach proposed allows understanding how the rocks and the water contained, respond to changes in the tensional state and the hydraulic pressure regime originated by mining operations. Moreover, the proposed approach identifies the spatial variability of pore pressures and the existence of heterogeneities and allow to achieve better coupled geotechnical models. However, in a system strongly controlled by geological structures where the flow of water in the hydrogeological units can be diverted and the measurement depends on the direction of sampling, its implementation is limited and requires extensive theoretical development, considering two dimensions for the cross space i.e., the azimuth and the inclination additionally to the three conventional coordinates (north, east and elevation).",1,https://api.osf.io/v2/files/5b0075b4e9cb340010b17a5e/,191,https://engrxiv.org/ch3vm/,10.31224/osf.io/ch3vm,,2018-05-19T19:12:53.767200,2018-07-02T11:53:22.423387 | |
| p43zn,"(Not) Throwing the Game - An Application of Markov Decision Processes and Reinforcement Learning to Optimising Darts Strategy","This article determines an aimpoint selection strategy for players in order to improve their chances of winning at the classic darts game of 501. Although many studies have considered the problem of aimpoint selection in order to maximise the expected score a player can achieve, few have considered the more general strategical question of minimising the expected number of turns required for a player to finish. By casting the problem as a Markov decision process and utilising the reinforcement learning method of value iteration, a framework is derived for the identification of the optimal aimpoint for a player in an arbitrary game scenario. This study represents the first analytical investigation of the full game under the normal game rules, and is, to our knowledge, the first application of reinforcement learning methods to the optimisation of darts strategy. The article concludes with an empirical study investigating the optimal aimpoints for a number of player skill levels under a range of game scenarios.",1,https://api.osf.io/v2/files/5afd4557ee2b5f000f44ba32/,419,https://engrxiv.org/p43zn/,10.31224/osf.io/p43zn,,2018-05-17T09:17:26.610695,2018-07-02T11:53:07.989746 | |
| kpx6n,"Designing Improved Teams for Crowdsourced Competitions","Teams are ubiquitous, woven into the fabric of engineering and design. Often, it is assumed that teams are better at solving problems than individuals working independently. Recent work in engineering, design, and psychology has indicated that teams may not be the problem-solving panacea that they were once thought to be. Crowdsourcing has seen increased interest in engineering design recently, and platforms often encourage teamwork between participants. This work undertakes an analysis of the performance of different team styles and sizes in crowdsourced competitions. This work demonstrates that groups of individuals working independently may outperform interacting teams on average, but that small interacting teams are more likely to win competitions. These results are discussed in the context of motivation for crowdsourcing participants.",1,https://api.osf.io/v2/files/5afc2206dbf98d000cff2f32/,227,https://engrxiv.org/kpx6n/,10.31224/osf.io/kpx6n,10.1115/DETC2018-85457,2018-05-16T12:22:53.100704,2018-07-02T11:53:06.770131 | |
| 3aynr,"Comments on ""Dual-rail asynchronous logic multi-level implementation""","In this research communication, we comment on “Dual-rail asynchronous logic multi-level implementation” [Integration, the VLSI Journal 47 (2014) 148–159] by expounding the problematic issues, and provide some clarifications on delay-insensitivity, robust asynchronous logic, multi-level decomposition, and physical implementation.",1,https://api.osf.io/v2/files/5afbc03413c138001004351c/,235,https://engrxiv.org/3aynr/,10.31224/osf.io/3aynr,10.1016/j.vlsi.2015.08.001,2018-05-16T05:31:30.402255,2018-07-02T11:53:05.959190 | |
| 6jnfv,"Microstructure Characteristics of Self Compacting Concrete using Sea Water","In the cycle of life, the needs of freshwater more and more. Infrastructure development is increasing. On the concrete industry, several billion tones of water used in earth as mixing water, treatment water (curing) and cleaner water every year, where using of sea water is obstructed. For that, the using of sea water which consists of 97% of the total water on earth is absolutely | |
| necessary. Self-compacting concrete (SCC) has dense microstructure. Knowledge about the microstructure and properties of each component a concrete and their relationship is useful to control the behavior. This research aims to know the relationship between compressive strength and microstructure characteristics of Self Compacting Concrete which using seawater up to the age of 90 days. The results of this study were the compressive strength of SCC using sea water is higher than the SCC using fresh water. Seawater does not reduce the strength of SCC concrete until the age of 90 days, | |
| but instead of Seawater is accelerating the development of SCC concrete strength at an early age. The compressive strength of concrete SCC is influenced by the phase microstructure (especially with tobermorite and portlandite) formed in the concrete.",1,https://api.osf.io/v2/files/5af8fc06da163200131faa13/,284,https://engrxiv.org/6jnfv/,10.31224/osf.io/6jnfv,,2018-05-14T03:40:04.662829,2018-07-02T11:51:31.146044 | |
| kmequ,"Porosity, pore size and compressive strength of self compacting concrete using sea water","Indonesia is the largest archipelago in the world, so it has much territory that the quality of the source water is not qualified as mixing water in construction. Besides, construction of concrete in areas that are likely quantity of water or fresh water is very minimal or even nothing then the sea water cannot be avoided in mixing concrete. This research was an experimental study, the samples for compressive strength test are cylindrical premises size of 10 mm×20 mm. The porosity relation, compressive power, age and model of porosity relationship with SCC concrete compressive strength which using sea water is discussed in this paper. Compressive strength testing is following the standard ASTM 39/C 39-99. Universal Testing Machine (UTM) was used in the testing of compressive strength. A test specimen for porosity created by taking part of the cylinder and then slashed with a size of approximately 2 cm×3 cm with a 0.003 mm thick. The type and pore size and porosity were analyzed by using a polarizing petrography microscope Olympus BX 51-P. The result of the research was increased the compressive strength and density of microstructures in line with the decrease in porosity and pore size of concrete and concrete age. Compressive strength relations (σ ss ) and porosity (p ss ) the SCC used seawater can be approximated equation σ ss = σ o (1-p)K, with σ o = 119.6 and K = 7.502.",1,https://api.osf.io/v2/files/5af8f4c97bf0b90010e663a1/,342,https://engrxiv.org/kmequ/,10.31224/osf.io/kmequ,10.1016/j.proeng.2015.11.045,2018-05-14T02:56:06.685869,2018-07-02T11:51:31.111283 | |
| njdcu,"Stochastic modeling of knee arthrometry for Intact, partial and ruptured ACL","Knee pain and injuries are very common in athletes. Anterior cruciate ligament (ACL) injury is one of the most important reason of knee acute and chronic pains. As ACL plays a significant role in knee stability and due to amount of reported ACL related injuries, much effort has been placed on finding proper and on time diagnosis and treatment of these injuries. Arthrometric methods are the most non-invasive reliable diagnosis option; however they are trusted to distinguish partial injuries from intact joint and instead expensive and more time consuming imaging diagnosis techniques (i.e MRI) are used. Arthromery results can be investigated by quantifying the tests using computer simulations; so far few studies have been conducted toward this goal. | |
| In this study a two dimensional finite flement (FE) model of knee joint under standard arthrometry state (by a KT-2000 arthrometer) was built. This model was then used to evaluate the effect of precise modeling of tibiofemoral contact-surface geometry with considering flexible articular cartilage in the joint. The results revealed that exact modeling of the contact geometry highly influences the simulation results. In the next step, the built model was used in a stochastic modeling with the experimental data obtained from literature in order to simulate a real diagnosis circumstance and to provide a statistical comparison between seven different levels of ACL injury. The result of this simulation shows that although arthrometry may be able to distinguish partial injuries from intact in most cases leading to less ACLD with appropriate treatment, but it is hard to tell anything about the level of injury. To prevent the costs of imaging techniques moving towards the introduction of new measuring methods (or newly defined identifiers) or using intelligent processing of currently obtained data is suggested.",1,https://api.osf.io/v2/files/5af5fb5d7bf0b90012e3e687/,144,https://engrxiv.org/njdcu/,10.31224/osf.io/njdcu,,2018-05-11T20:29:44.079489,2018-07-02T11:51:28.134724 | |
| yz4a7,"An efficient multiscale modeling framework for nonlinear analyses of composite structures","Traditional multiscale modeling methods of composite structures are based on the global-local approach whereby the global analysis of structures are first performed to determine potential damage regions, followed by local analyses at those regions to identify detailed damage patterns and failure modes. Such an approach does not take into account the localized effects of critical regions on the global analysis and may become less accurate in general. To address better the behavior of local regions on multiscale analyses, homogenization-based multiscale methods are applied. For each load increment, the global problem is solved simultaneously with one Representative Volume Element (RVE) equilibrium problem for each Gauss point of the global mesh. This approach is successful to capture the local behavior at each material point; however, it is computationally expensive since the RVE is called at all the Gauss points in the global model for each load increment. | |
| We develop an efficient multiscale modeling method whereby the RVE analyses are only called at specialized locations by multiscale elements and run parallel with the global analysis. The constitutive models of multiscale elements are defined in a user-defined element subroutine (UEL) where stiffnesses of the multiscale elements are unknown at the beginning of the analysis. They can only be obtained by performing a series of RVE analyses for each set of loads received from the global analysis. The advantage of the proposed method is that the stiffnesses of the multiscale elements are directly computed from the RVE analyses and keep updated for each global load increment. The nested multiscale modeling is implemented by Python script and highly capable for nonlinear analysis of composite structures.",1,https://api.osf.io/v2/files/5af59fd0a5bbbc000fc78e60/,266,https://engrxiv.org/yz4a7/,10.31224/osf.io/yz4a7,,2018-05-11T13:52:41.598523,2019-03-10T06:51:28.208396 | |
| j25pa,"Note on the generation of long gravity waves by breaking and shoaling of short-wave groups in gently-sloping beaches: the long-wave similarity parameter","It is proposed a long-wave similarity parameter based on the surf-beat similarity and Ursell parameters. By including the Ursell number, the long-wave similarity allows distinguishing between breaking and shoaling generation of long-waves for conditions rendering similar values of surf-beat similarity. The proposed parameter is tested with three cases of wave conditions published in the literature, with promising results.",1,https://api.osf.io/v2/files/5af4dd60a5bbbc000fc6b1d6/,304,https://engrxiv.org/j25pa/,10.31224/osf.io/j25pa,,2018-05-11T00:53:08.102363,2018-07-02T11:51:26.358964 | |
| rvtgs,"Bounding Surface Elasto-Viscoplasticity: A General Constitutive Framework for Rate-Dependent Geomaterials","A general framework is proposed to incorporate rate and time effects into bounding surface (BS) plasticity models. For this purpose, the elasto-viscoplasticity (EVP) overstress theory is combined with bounding surface modeling techniques. The resulting constitutive framework simply requires the definition of an overstress function through which BS models can be augmented without additional constitutive hypotheses. The new formulation differs from existing rate-dependent bounding surface frameworks in that the strain rate is additively decomposed into elastic and viscoplastic parts, much like classical viscoplasticity. Accordingly, the proposed bounding surface elasto-viscoplasticity (BS-EVP) framework is characterized by two attractive features: (1) the rate-independent limit is naturally recovered at low strain rates; (2) the inelastic strain rate depends exclusively on the current state. To illustrate the advantages of the new framework, a particular BS-EVP constitutive law is formulated by enhancing the Modified Cam-clay model through the proposed theory. From a qualitative standpoint, this simple model shows that the new framework is able to replicate a wide range of time/rate effects occurring at stress levels located strictly inside the bounding surface. From a quantitative standpoint, the calibration of the model for over-consolidated Hong Kong marine clays shows that, despite the use of only six constitutive parameters, the resulting model is able to realistically replicate the undrained shear behavior of clay samples with OCR ranging from 1 to 8, and subjected to axial strain rates spanning from 0.15%/hr to 15%/hr. These promising features demonstrate that the proposed BS-EVP framework represents an ideal platform to model geomaterials characterized by complex past stress history and cyclic stress fluctuations applied at rapidly varying rates.",1,https://api.osf.io/v2/files/5af4d337d6e6eb001023930f/,349,https://engrxiv.org/rvtgs/,10.31224/osf.io/rvtgs,,2018-05-10T23:30:51.006615,2019-04-10T10:54:43.171158 | |
| a76hr,"Computational Modeling of Polymer Matrix Composites","Applications of polymer matrix composites are growing in aerospace and offshore industries due to the light-weight and good mechanical properties of composite materials. The design of composite materials can be made at macroscopic level in which the composite mechanical properties can be tailored to offer the most desired performance of composite structures. Understanding on mechanical behavior of the composite material may require detailed investigations at the microscopic level involving the behaviour of the composite constituents such as the fiber, the polymer matrix and the fiber/matrix interface under macroscopic loads. Composite failure criteria are often employed to evaluate the failure of composite material and its constituents. Computational damage models can be then developed to reflect the stiffness reduction of the material once damage at the macro- and micro- scales of the composite is indicated. The successful prediction of composite structures relies on consistent computational models which can capture the mechanical behaviour of composite materials at different length scales.",1,https://api.osf.io/v2/files/5af4ca49a5bbbc0010c5f3cc/,281,https://engrxiv.org/a76hr/,10.31224/osf.io/a76hr,,2018-05-10T22:43:53.751346,2019-03-10T06:45:53.500201 | |
| 6yme2,"An experimental and signal analysis workflow for detecting cold-induced noise emissions (cold squealing) from porous journal bearings","We employ a variant of the joint time-frequency analysis (JTFA) for identifying transient, temperature-dependent noise emitted from porous journal bearings operated at temperatures between -40°C and 0°C. This phenomenon, called ""cold squealing"", is difficult to reproduce in laboratory environments, as it requires a suitable (and typically system-specific) resonator to occur. We systematically tested real-world bearings impregnated with various oils on a custom-designed experimental rig, fitted with a coolable sample holder and a vibration sensor, over a range of rotational speeds. By analyzing temperature-differential JTFA signal maps, we succeeded in detecting transient cold-squealing as well as ranking the bearing lubricants according to their low-temperature quiet running properties.",1,https://api.osf.io/v2/files/5ae9adc5e1f80c000d834a2b/,307,https://engrxiv.org/6yme2/,10.31224/osf.io/6yme2,,2018-05-02T12:29:55.493485,2018-07-02T11:50:34.707000 | |
| e8j3w,"The effect of out-of-plane deformation on ligament surface strain measurements","The characterization of biological tissues depends on accurate measurements of deformation and strain, but less attention has been given to the role of out-of-plane deformation in ligament strain. The objective of this study was to investigate the influence of out-of-plane deformation on surface strain measurements in healthy and damaged ligaments. Tensile tests on five porcine posterior cruciate ligaments (PCL) were performed before and after damage using the femur – PCL – tibia construct. Damage was simulated by loading the ligament to its maximum force capacity. Digitized surface dots were tracked using an optical motion capture system. The transverse strain (ε_xx), longitudinal strain (ε_yy), and shear strain (γ_xy) distributions on the ligament surface were obtained for the control and damaged states using two-dimensional (2d) strain and three-dimensional (3d) strain measurements. There was no significant difference between the 2d and 3d strains in the control state for all three strains. However, the value and location of the peak strain values (tensile and compressive) in ligament surfaces did change. The 2d peak tensile strain was both over and under-estimated, compared to 3d strain, when out of plane deformation was included for ε_xx and ε_yy; but consistently overestimated for positive γ_xy. The percentage of damaged regions, quantified as a loss in tensile strength, after damage was overpredicted by 2d strain for ε_yy. Care should be taken when using 2d surface strain as peak values and local damage is sensitive to out-of-plane deformation.",1,https://api.osf.io/v2/files/5ae8a36e91de99000e1ad9e0/,296,https://engrxiv.org/e8j3w/,10.31224/osf.io/e8j3w,,2018-05-01T17:32:35.353176,2018-07-02T11:50:33.429246 | |
| ksfbu,"Impossible by design? Fairness, strategy, and Arrow’s impossibility theorem","The design process often requires work by teams, rather than individuals. During team based design it is likely that situations will arise in which individual members of the team have different opinions, yet a group decision must still be made. Unfortunately, Arrow’s impossibility theorem indicates that there is no method for aggregating group preferences that will always satisfy a small number of ‘fair’ conditions. This work seeks to identify methods of combining individual preferences that can come close to satisfying Arrow’s conditions, enabling decisions that are fairer in practice. First, experiential conjoint analysis was used to obtain individual empirical utility functions for drinking mug designs. Each empirical utility function represented individual members who were part of a design team. Then, a number of functions for constructing group preference were analysed using both randomly generated preferences and empirical preferences derived from the experiential conjoint survey. The analysis involved checking each of Arrow’s conditions, as well as assessing the potential impact of strategic voting. Based on the results, methods that should be used to aggregate group preference within a design team in practice were identified and recommended.",1,https://api.osf.io/v2/files/5ae86b32bf84a8000e9e562b/,213,https://engrxiv.org/ksfbu/,10.31224/osf.io/ksfbu,10.1017/dsj.2017.1,2018-05-01T13:35:06.973933,2018-07-02T11:50:32.606660 | |
| c7pg6,"Mining Process Heuristics from Designer Action Data via Hidden Markov Models","Configuration design problems, characterized by the assembly of components into a final desired solution, are common in engineering design. Various theoretical approaches have been offered for solving configuration type problems, but few studies have examined the approach that humans naturally use to solve such problems. This work applies data-mining techniques to quantitatively study the processes that designers use to solve configuration design problems. The guiding goal is to extract beneficial design process heuristics that are generalizable to the entire class of problems. The extraction of these human problem-solving heuristics is automated through the application of hidden Markov models to the data from two behavioral studies. Results show that designers proceed through four procedural states in solving configuration design problems, roughly transitioning from topology design to shape and parameter design. High-performing designers are distinguished by their opportunistic tuning of parameters early in the process, enabling a more effective and nuanced search for solutions.",1,https://api.osf.io/v2/files/5ae86a5891de99000e1aa541/,253,https://engrxiv.org/c7pg6/,10.31224/osf.io/c7pg6,10.1115/1.4037308,2018-05-01T13:25:14.141317,2018-07-02T11:50:32.548418 | |
| zetj9,"Capturing Human Sequence-Learning Abilities in Configuration Design Tasks through Markov Chains","Designers often search for new solutions by iteratively adapting a current design. By engaging in this search, designers not only improve solution quality but also begin to learn what operational patterns might improve the solution in future iterations. Previous work in psychology has demonstrated that humans can fluently and adeptly learn short operational sequences that aid problem-solving. This paper explores how designers learn and employ sequences within the realm of engineering design. Specifically, this work analyzes behavioral patterns in two human studies in which participants solved configuration design problems. Behavioral data from the two studies are first analyzed using Markov chains to determine how much representation complexity is necessary to quantify the sequential patterns that designers employ during solving. It is discovered that first-order Markov chains are capable of accurately representing designers' sequences. Next, the ability to learn first-order sequences is implemented in an agent-based modeling framework to assess the performance implications of sequence-learning abilities. These computational studies confirm the assumption that the ability to learn sequences is beneficial to designers.",1,https://api.osf.io/v2/files/5ae86947bf84a800109e3637/,319,https://engrxiv.org/zetj9/,10.31224/osf.io/zetj9,10.1115/1.4037185,2018-05-01T13:21:59.207302,2018-07-02T11:50:32.498957 | |
| d4peq,"Optimizing Design Teams Based on Problem Properties: Computational Team Simulations and an Applied Empirical Test","The performance of a team with the right characteristics can exceed the mere sum of the constituent members’ individual efforts. However, a team having the wrong characteristics may perform more poorly than the sum of its individuals. Therefore, it is vital that teams are assembled and managed properly in order to maximize performance. This work examines how the properties of configuration design problems can be leveraged to select the best values for team characteristics (specifically team size and interaction frequency). A computational model of design teams which has been shown to effectively emulate human team behavior is employed to pinpoint optimized team characteristics for solving a variety of configuration design problems. These configuration design problems are characterized with respect to the local and global structure of the design space, the alignment between objectives, and the resources allotted for solving the problem. Regression analysis is then used to create equations for predicting optimized values for team characteristics based on problem properties. These equations achieve moderate to high accuracy, making it possible to design teams based on those problem properties. Further analysis reveals hypotheses about how the problem properties can influence a team’s search for solutions. This work also conducts a cognitive study on a different problem to test the predictive equations. For a configuration problem of moderate size, the model predicts that zero interaction between team members should lead to the best outcome. A cognitive study of human teams verifies this surprising prediction, offering partial validation of the predictive theory.",1,https://api.osf.io/v2/files/5ae8679991de99000f1aa8c4/,280,https://engrxiv.org/d4peq/,10.31224/osf.io/d4peq,10.1115/1.4035793,2018-05-01T13:13:12.152685,2018-07-02T11:50:32.260816 | |
| pmbfh,"Drawing Inspiration From Human Design Teams For Better Search And Optimization: The Heterogeneous Simulated Annealing Teams Algorithm","Insights uncovered by research in design cognition are often utilized to develop methods used by human designers; in this work such insights are used to inform and improve computational methodologies. This paper introduces the Heterogeneous Simulated Annealing Team (HSAT) algorithm, a multi-agent simulated annealing algorithm. HSAT is based on a validated computational model of human-based engineering design, and retains characteristics of the model that structure interaction between team members and allow for heterogeneous search strategies to be employed within a team. The performance of this new algorithm is compared to several other simulated annealing based algorithms on three carefully selected benchmarking functions. The HSAT algorithm provides terminal solutions that are better on average than other algorithms explored in this work.",1,https://api.osf.io/v2/files/5ae866c4bf84a8000e9e5184/,242,https://engrxiv.org/pmbfh/,10.31224/osf.io/pmbfh,10.1115/1.4032810,2018-05-01T13:10:13.361091,2018-07-02T11:50:32.139674 | |
| w86ke,"A structure-based algorithm for automated separation of subchondral bone in micro-computed tomography data","Structural measurements of subchondral and trabecular bone are of interest for a wide variety of communities ranging from anthropology to biomechanical engi- neering, yet continues to be a challenge partly because of the lack of automated techniques for use with high resolution data. Here we present a structure-based algorithm for separating cortical compartments from trabecular bone in binarized images. Using the thickness of the cortex as a seed value, bone connected to the cortex within a spatially local threshold value is identified and separated from the remaining bone. The algorithm was tested on biological images from human, chim- panzee, and gorilla datasets and compared to manual measurements. The average error was 2-3 voxel differences in thickness and total area errors were less than ten percent. The algorithm is repeatable, efficient, and requires few user inputs, provid- ing a means of separating cortical from trabecular bone. The Matlab code, example images, and datasets can be downloaded from uitbl.mechse.illinois.edu.",1,https://api.osf.io/v2/files/5ae563d330777c000fdd4cfd/,457,https://engrxiv.org/w86ke/,10.31224/osf.io/w86ke,,2018-04-29T06:24:37.958646,2018-08-25T20:38:58.033592 | |
| nw4pj,"Misuse of pre-exponential factor in the kinetic and thermodynamic studies using thermogravimetric analysis and its implications","This paper describes the misuse of Arrhenius pre-exponential factor in the kinetic and thermodynamic studies using thermogravimetry. Standard test method (ASTM E698) has been used recently by many researchers to calculate the pre-exponential factor. ASTM E698 is reserved for differential scanning calorimetry (DSC) and impose many restrictions which have being overlooked by many recently. The obtained pre-exponential factors have been used to describe the thermodynamic behavior during the course of thermal conversions. The objective of this paper is to inform the readers that the pre-exponential factor obtained from the restricted equation can mislead and generate some false thermodynamic data.",1,https://api.osf.io/v2/files/5ae41d3830777c000ddcc947/,295,https://engrxiv.org/nw4pj/,10.31224/osf.io/nw4pj,10.1016/j.biteb.2018.04.011,2018-04-28T07:09:12.592037,2018-07-02T11:50:10.837455 | |
| kvqmh,"Design of a Low-Cost Open-Source Underwater Glider","Typical buoyancy engine-based Underwater Gliders are highly-complex and cost-prohibitive, generally ranging in price-point from 50,000USD to 250,000USD. A low-cost, Open-Source Underwater Glider (OSUG) was thus developed as a low-cost data-collection and research tool. This glider, OSUG, is a sub-1000USD, 1.2m long, 12kg, and capable of 50-hours of continuous operation. Its efficiency, and use-case feasibility were evaluated. The buoyancy engine is constructed of medical grade syringes that pull in water from the environment to simplify the system and lower costs. Direction of locomotion is controlled by altering pitch and roll via changing the center-of-mass. The system was designed to be primarily three-dimensionally (3D) printed and fully-modular to limit cost and ensure reproducibility.",1,https://api.osf.io/v2/files/5ae2dd41bb99c0000e4880f0/,727,https://engrxiv.org/kvqmh/,10.31224/osf.io/kvqmh,,2018-04-27T08:24:24.602045,2018-07-02T11:50:10.378198 | |
| fsqcz,"ENABLING GRADUATE ENGINEERING STUDENTS WITH PROFICIENCY IN MOBILE ROBOTICS","In recent years, an aggressive expansion of research as well as commercialization efforts in autonomous vehicles can be witnessed. At the same time, many existing companies have expanded their portfolio to autonomous technologies as well (e.g. NVIDIA). This has created an already large need for autonomous-vehicle engineers who are not only proficient in single traditional engineering fields (e.g. mechanical) and old-school automotive studies, but who also have acquired the significantly different, interdisciplinary skillset for mobile robotics. Unlike students of computer science, mechanical engineering graduate students are hardly exposed to coding and robotic system integration in current traditional curricula. The new demands of the automotive industry require an automotive engineer who understands the science of autonomy as well as its impact on the design and implementation of autonomous vehicles, and is equipped with hands-on experience with the latest technology in the field. | |
| We describe a unique education program that draws content from traditional courses on mobile-robotics as well as incorporates experiential learning by hands-on training in software, specifically addressing the skill gap in traditional automotive engineering education. Geared towards engineering students with no previous training in robotic system integration, and with only basic undergraduate understanding of programming languages, the teaching experiment employed an active learning approach to introduce numerous concepts as a host of hands-on exercises on multiple robotic platforms. Beginning with simple tutorials on networked communication to demonstrate the power of ROS, the course built up to complete control system design on a student-built RC car that can avoid obstacles and navigate a racecourse by performing SLAM. | |
| A brief evaluation of the course exhibited good student performance in general with unique and creative approaches to the programming tasks in particular. Although employing different approaches, each student team was able to demonstrate comparable, efficient performance.",1,https://api.osf.io/v2/files/5ae235cebb99c00010488344/,359,https://engrxiv.org/fsqcz/,10.31224/osf.io/fsqcz,,2018-04-26T20:43:47.444942,2018-07-02T11:50:09.597016 | |
| p5ytr,"Perceived Quality Attributes Framework and Ranking Method.","Perceived quality (PQ) is one of the most important product attributes in the automotive industry that defines successful automotive design. This paper presents a new approach regarding PQ assessment by examining PQ decomposed into a structure with the top-down approach to the level of basic (“ground”) attributes, covering almost every aspect of car quality perception from the engineering viewpoint. The paper proposes a novel method for PQ attributes relative importance ranking, resulting in the PQ balance of the vehicle, within the given conditions. The proposed method helps to reach the equilibrium of the vehicle’s quality equation from the perspective of design effort, time and costs estimations. The authors introduce the Perceived Quality Framework (PQF), which is the taxonomy system for PQ attributes and the core of the attributes importance ranking method. The research outcomes are based on findings of qualitative exploratory study that includes the European and North American premium and luxury automotive manufacturers. To validate the proposed method, an industrial pilot study was performed with one of the automotive companies to examine the PQ attributes importance ranking obtained from automotive industry professionals. The results can significantly improve PQ assessment during all stages of product development.",1,https://api.osf.io/v2/files/5ae088496774af000f757477/,492,https://engrxiv.org/p5ytr/,10.31224/osf.io/p5ytr,,2018-04-25T14:00:52.977726,2018-07-02T11:50:07.010494 | |
| tdk4s,"An experimental framework for determining wear in porous journal bearings operated in the mixed lubrication regime","We present an experimental and analysis workflow to characterize the tribological behavior and the wear resistance of porous journal bearing systems operating at high loads and small rotational speeds. Our approach consists of a laser-instrumented tribometer that allows parallel testing of five bearings, an experimental procedure that is optimized for producing sufficient wear during mixed lubrication operation while maintaining realistic operating conditions, as well as several methods to visualize and quantify bearing wear. The simultaneous testing of five bearings prevents outliers from distorting the results and yields a statistical estimation of the performance variations between nominally equivalent tribosystems. We showcase our approach by analyzing the influence of the bearing material and its porosity on mixed-lubrication friction and wear.",1,https://api.osf.io/v2/files/5ae0752c6774af001074efd9/,384,https://engrxiv.org/tdk4s/,10.31224/osf.io/tdk4s,10.1016/j.triboint.2018.02.026,2018-04-25T12:42:51.995433,2018-07-02T11:50:06.826766 | |
| fv47e,"MultiDIC: an Open-Source Toolbox for Multi-View 3D Digital Image Correlation","Three-dimensional Digital Image Correlation (3D-DIC) is a non-contact optical-numerical technique for evaluating the dynamic mechanical behavior at the surface of structures and materials, including biological tissues. 3D-DIC can be used to extract shape and full-?eld displacements and strains with high resolution, at various length scales. While various commercial and academic 3D-DIC software exist, the field lacks 3D-DIC packages which offer straightforward calibration and data-merging solutions for multi-view analysis, which is particularly desirable in biomedical applications. To address these limitations, we present MultiDIC, an open-source MATLAB toolbox, featuring the first 3D-DIC software specifically dedicated to multi-view setups. MultiDIC integrates robust two-dimensional subset-based DIC software with specially tailored calibration procedures, to reconstruct the dynamic behavior of surfaces from multiple stereo-pairs. MultiDIC contains novel algorithms to automatically merge meshes from multiple stereopairs, and to compute and visualize 3D shape and full-?eld motion, deformation, and strain. User interfaces provide capabilities to perform 3D-DIC analyses without interacting with MATLAB syntax, while standalone functions also allow proficient MATLAB users to write custom scripts for specific experimental requirements. This paper discusses the challenges underlying multi-view 3D-DIC, details the proposed solutions, and describes the algorithms implemented in MultiDIC. The performance of MultiDIC is tested using a low-cost experimental system featuring a 360-deg 12-camera setup. The software and system are evaluated using measurement of a cylindrical object with known geometry subjected to rigid body motion and measurement of the lower limb of a human subject. The findings confirm that shape, motion, and full-field deformations and strains can be accurately measured, and demonstrate the feasibility of MultiDIC in multi-view in-vivo biomedical applications.",1,https://api.osf.io/v2/files/5ada3d38144be4000f7a6211/,1989,https://engrxiv.org/fv47e/,10.31224/osf.io/fv47e,10.1109/ACCESS.2018.2843725,2018-04-20T19:25:14.916811,2019-01-10T23:06:32.279387 | |
| kd695,"Comments on “Asynchronous Logic Implementation Based on Factorized DIMS”","This research correspondence comments on “Asynchronous Logic Implementation Based on Factorized DIMS” [Journal of Circuits, Systems, and Computers, vol. 26, no. 5, pp. 1750087-1-1750087-9, May 2017] with respect to two problematic issues: i) the gate orphan problem implicit in the factorized DIMS approach discussed in the referenced article which affects its strong-indication, and ii) how the enumeration of product terms to represent the synthesis cost is skewed in the referenced article because the logic expression contains sum of products and also product of sums. It is observed that the referenced article has not provided a general logic synthesis algorithm excepting only an example illustration involving a 3-input AND logic function. The absence of a general logic synthesis algorithm would make it difficult to reproduce the research described in the referenced article. Moreover, the example illustration in the referenced article describes an unsafe quasi-delay-insensitive logic decomposition which is not suitable for the multi-level synthesis of strong-indication asynchronous circuits. Further, a logic synthesis method which safely decomposes the DIMS solution to synthesize multi-level strong-indication asynchronous circuits is available in the existing literature, which was neither cited nor taken up for comparison in the referenced article, which is another drawback. Subsequently, it is concluded that the referenced article has not advanced existing knowledge in the field but on the contrary, has caused confusions. Hence, in the interest of readers, this work additionally highlights some important and relevant literature which provide valuable information about robust asynchronous circuit synthesis techniques which employ delay-insensitive codes for data representation and processing and a 4-phase handshake protocol (return-to-zero) for data communication.",1,https://api.osf.io/v2/files/5ad9c63b144be400117990ed/,242,https://engrxiv.org/kd695/,10.31224/osf.io/kd695,,2018-04-20T10:59:47.592811,2018-07-02T11:48:45.815486 | |
| dz8wq,"Information System Design Of Goods Stock Using Framework For The Application Of System Thinking (FAST) Method (Case Study CV. Aneka Mandiri Lestari)","CV. Aneka Mandiri Lestari constitutes resulting company earth. Current stock management processes that are running in the CV. Aneka Mandiri Lestari is still done in a simple to use computer tool. However, systems that use has not been specifically designed for the purposes. Some data related to the management of the stocks on CV. Aneka Mandiri Lestari still organised and recorded using book so difficult in the process serving and reporting information associated. Information systems Design of goods stock It is a system that can handle the problem of inventory items, including the recording of incoming goods, against goods that come out, the purchase of raw materials, goods that are in the warehouse, and also reporting. This information system architecture using the FAST (Framework for the Application of System Technique) method. Based on the results of the functional testing, obtained that 100% of the system is valid. While the results from testing the usability, for the ease of use factor of 65% and activities of the experiment system based on scenario 85.5% of respondents strongly agree to ease of use this system. So from the test results it can be concluded that by using this stock information system can make CV Aneka Mandiri Lestari in the running of its business processes and systems that have been built can be received by users. To assist in processing stock items and sales generated a new system design, i/o design, database design and systems built using Visual Basic.Net The results of the data processing system of the manufacture and distribution of stock this stuff makes it easy for employees to entry, fix (edit), erase (delete), and search (searching) data reception and spending on goods, so as to facilitate in reporting revenue and expenditure items",1,https://api.osf.io/v2/files/5ad9be72144be4001279870e/,327,https://engrxiv.org/dz8wq/,10.31224/osf.io/dz8wq,,2018-04-20T10:19:59.526272,2018-07-02T11:48:45.760523 | |
| 2cr98,"INFORMATION SYSTEM SALES OF INDOOR AND OUTDOOR ORNAMENTAL PLANTS-BASED ONLINE","Ornamental plants have fairly high commercial value and much sought after by various circles. The prospect is in the business of ornamental plants can be said very brilliant and profitable. Where is in the business of ornamental plants can bring about advantages not the least. The business struggled with ornamental plants can have very favorable prospects for the long term. There are an awful lot of various kinds of ornamental plants that we can choose to use as ornaments to beautify residential home. The ornamental plants can be used as indoor ornamental plants placed in homes or can also be used as outdoor ornamental plants grown in the garden. Ornamental plants while more popular community-wide information system for ornamental plant however is currently designed specifically and not many people who know the information on price and specs or type of indoor and outdoor ornamental plants so that the need for sales information system of indoor and outdoor ornamental plants-based online. With the sales information system of Indoor and Outdoor ornamental plants-based online is expected to facilitate the customers, business processes that occur in the company's units, unit – units that exist within the system a functioning production units as the unit working on/produce ornamental plants. With the utilization of the system marketing media, promoting, finding new customers, the sales process, recapitulation payment of ornamental plants, control the conditions of stock products, development and delivery of products to customers including convincing the product gets to the customer",1,https://api.osf.io/v2/files/5ad9bdbfb855b8000ffb8699/,205,https://engrxiv.org/2cr98/,10.31224/osf.io/2cr98,,2018-04-20T10:16:12.633694,2018-07-02T11:48:45.629200 | |
| w86gs,"PERANCANGAN SISTEM INFORMASI MONITORING PROGRES PENGADAAN BARANG PADA BAGIAN PENGADAAN DAN LOGISTIK INSTITUT INFORMATIKA DAN BISNIS DARMAJAYA","Institute of Information Technology and Business Darmajaya is a leading private | |
| college fast growing and should be balanced with meeting facilities and infrastructure as | |
| well. Managing the procurement function is handled by the Procurement and Logistics | |
| Sections that have applied computer technology in assisting the administration of the | |
| procurement process. To improve performance and simplify the process of monitoring the | |
| progress of procurement of goods, it is necessary to build the information system | |
| monitoring the progress of the procurement is expected to facilitate the stretcher in | |
| overseeing and ensuring the procurement process is run in accordance with the agreed | |
| terms. Information systems development is done using structured analysis and design | |
| methodology.",1,https://api.osf.io/v2/files/5ad9bd19144be40010799475/,220,https://engrxiv.org/w86gs/,10.31224/osf.io/w86gs,,2018-04-20T10:13:27.251794,2018-07-02T11:48:45.499987 | |
| bgs42,"Identifikasi Penyakit Diabetes Millitus Menggunakan Jaringan Syaraf Tiruan Dengan Metode Perambatan-Balik (Backpropagation)","Diabetes Melitus (DM) is dangerous disease that affect many of the various | |
| layer of work society. This disease is not easy to accurately recognized by the | |
| general society. So we need to develop a system that can identify accurately. System | |
| is built using neural networks with backpropagation methods and the function | |
| activation sigmoid. Neural network architecture using 8 input layer, 2 output layer | |
| and 5 hidden layer. The results show that this methods succesfully clasifies data | |
| diabetics and non diabetics with near 100% accuracy rate.",1,https://api.osf.io/v2/files/5ad9bcbe144be40011798a5a/,540,https://engrxiv.org/bgs42/,10.31224/osf.io/bgs42,,2018-04-20T10:12:06.650165,2018-07-02T11:48:45.425768 | |
| cw5pf,"Perancangan Data Warehouse dan Penerapan Data Mining Di Bidang Akademik Pada Institut Informatika Dan Bisnis Darmajaya","Higher education institution must be able to well perform processes of | |
| evaluation, planning and management in order to win the competition in this | |
| globalization era. To support any effort of the aforementioned, the institution needs | |
| qualified and sufficient information supports so that it can probe and predict any | |
| potential strength which existed. | |
| Development data warehouse and data mining is kinds of solution alternatives | |
| which can be done to help organization in finding and understanding hidden patterns | |
| from the data provided. Data warehouse is a collection of integrated databases | |
| which is used to support the process of decision making. Data mining is a kind of | |
| analysis tool which is used to extract any information provided in the data | |
| warehouse. | |
| The research discussed a problem in designing data warehouse and applying | |
| data mining to support the academic system at IBI Darmajaya in representing | |
| potential information required for better academic services to learners. The first | |
| executed steps was establishing the data warehouse of IBI Darmajaya, then an | |
| analysis was conducted towards all saved data in the data warehouse by using data | |
| mining techniques. | |
| The results of this research is a data warehouse that can represent information | |
| to support the evaluation process and acceptance of new students campaign planning | |
| to the potential areas and school, advertising media that will be used, monitoring of | |
| students’ academic status, evaluation and planning of students’ study plans, and | |
| performance evaluation of study program within the aspects of alumni quality and | |
| length of study. In addition, this research also result the application of data mining | |
| for finding the rules that used to driving and directing the students enthusiast and | |
| study program selection for prospective new students.",1,https://api.osf.io/v2/files/5ad9bc4a144be4000f79aece/,227,https://engrxiv.org/cw5pf/,10.31224/osf.io/cw5pf,,2018-04-20T10:10:24.127550,2018-07-02T11:48:45.378516 | |
| r2byd,"Perancangan Prototype Sistem Informasi Layanan Akademis Sekolah Berbasis Cloud Computing","Academic service system is one of the supporting elements in education in high school | |
| or universities. Despite the rising awareness of the usefulness of the IT based academic | |
| system, some education institutions do not have the ability of developing and | |
| implementing the system, especially due to the limited financial condition. The | |
| development of cloud computing based information system appears as a new paradigm | |
| in IT world which enable the school to implement IT based academic information | |
| system without investing big expenses of IT tools. The research is to learn the design of | |
| architecture system and prototype system of the supporting software for the school | |
| academic services. The result of this study would be the computer software to | |
| implement at school to improve the academic system especially those schools with | |
| limited financial condition and resources in developing the system",1,https://api.osf.io/v2/files/5ad9ba1eb855b8000ffb8301/,234,https://engrxiv.org/r2byd/,10.31224/osf.io/r2byd,,2018-04-20T10:00:44.098659,2018-07-02T11:48:45.320340 | |
| 4kvzt,"Perancangan Sistem Informasi Pendataan Penelitian Dosen Di Lingkungan Kopertis Wilayah II Palembang","It is important for lecturers to improve the quantity and quality of their research. To | |
| support this, Kopertis Wilayah II oftenly provides some grants for the lecturers to improve | |
| their research. With more research carried out, good data information system of | |
| lecturers’ research is needed. Making use of information technology can be a solution to | |
| fulfill the need of information related to the lecturers’ research as well as to check the | |
| lecturers’ research data to minimize the plagiarism practices and the problems of | |
| redundancies in lecturers title of research.",1,https://api.osf.io/v2/files/5ad9b9c3144be4001279840f/,212,https://engrxiv.org/4kvzt/,10.31224/osf.io/4kvzt,,2018-04-20T09:59:19.770481,2018-07-02T11:48:45.266995 | |
| bth6x,"Rancang Bangun Sistem Layanan Terpadu Tanaman Hias Berbasis Web","Floriculture has high commercial value and it is interested by many people. Floryculture | |
| bussiness grows fastly and it is very needed by people especially in big cities. Developing | |
| integrated masterplan system of web based floriculture is one of alternatives using computer | |
| technology to simplify operation of successfully decorated plant. To develop integrated | |
| master plan system of web based floriculture, it is firstly done necessity analysis process of | |
| that system by identifying of necessity through usecase, event, and things. Implementation | |
| of integrated master plan system of web based floriculture can increase service quality and | |
| simplify transaction of selling floriculture.",1,https://api.osf.io/v2/files/5ad9b93c144be4000f79ab99/,336,https://engrxiv.org/bth6x/,10.31224/osf.io/bth6x,,2018-04-20T09:57:12.476664,2018-07-02T11:48:45.219328 | |
| c6vdm,"Rancangan Aplikasi Manajemen User untuk Mendukung Aplikasi Sistem Informasi","Today many institutions are increasingly aware of the benefits and positive effects of the | |
| existence of information systems are built, and implemented as an optimization effort of | |
| information technology to support existing business processes. Information system is built in an | |
| institution/agency should be able to apply the rules that apply correct management. In some | |
| cases the application of information systems, users management problem often neglected and not | |
| well-designed so that potential deviations that can be harmful the institution. User management | |
| and sharing permissions within the system should be limited and well handled to minimize the | |
| occurrence of irregularities, in addition to data security needs to be done also periodic backup | |
| and continuous data.",1,https://api.osf.io/v2/files/5ad9b23bb855b8000cfb4533/,279,https://engrxiv.org/c6vdm/,10.31224/osf.io/c6vdm,,2018-04-20T09:28:01.753810,2018-07-02T11:48:45.138810 | |
| 2acfv,"Perancangan Sistem InformasiPenelusuran Data Alumni Berbasis Web","Alumni’s success in getting jobs that are suitable with their competence and with appropriate | |
| income soon after graduation is an indicator of success of a study program. Therefore, it is | |
| necessary to develop a system that can help track the alumni data easily. The development of the | |
| information system of web-based alumni data tracking can be an alternative solution taking into | |
| consideration that the alumni can report the development of their career wherever and whenever | |
| they would like to. However, for the purpose of the completeness of the alumni data, it is | |
| necessary to develop a variety of attributes to track alumni data more completely",1,https://api.osf.io/v2/files/5ad9b170144be40012797cda/,293,https://engrxiv.org/2acfv/,10.31224/osf.io/2acfv,,2018-04-20T09:23:54.764644,2018-07-02T11:48:45.104124 | |
| b36xz,"Advances in the treatment of the electromagnetic cascade in the TRIPOLI-4® Monte-Carlo code","TRIPOLI-4® is a Monte-Carlo particle-transport code developed at CEA-Saclay (France) that is employed in the domains of nuclear-reactor physics, criticality-safety, shielding/radiation protection and nuclear instrumentation. The goal of this paper is to report on current developments, validation and verification made in TRIPOLI-4® in the treatment of electron/positron/photon transport. The new capabilities and improvements concern refinements to the electron transport algorithm, the introduction of a charge-deposition score, the new thick-target bremsstrahlung option, the upgrade of the bremsstrahlung model and the improvement of electron angular straggling at low energy. The importance of each of the developments above is illustrated by comparisons with calculations performed with other codes and with experimental data.",1,https://api.osf.io/v2/files/5ad88d44694cf9000ef3af49/,242,https://engrxiv.org/b36xz/,10.31224/osf.io/b36xz,,2018-04-19T15:35:15.272541,2018-07-02T11:48:43.571803 | |
| 7efw3,"Methods of Stabilization of Gas Condensates","Gas condensates are liquid mixtures of high-boiling hydrocarbons of various structures, separated from natural gases during their production at gas condensate fields. When transporting gas through pipelines, the following gas quality conditions should be met: | |
| i. During transportation, gases should not cause corrosion of pipelines, fittings, instruments, etc. | |
| ii. The quality of the gas must ensure its transportation in a single-phase state i.e., liquid hydrocarbons, gas condensates and hydrates should not form in the pipelines. | |
| In order for gas condensates to meet the above-mentioned quality conditions during storage or transportation, they must be stabilized. Gas condensate stabilization is the process of “boiling off” light hydrocarbons from the condensate that would otherwise increase the vapor pressure when conditions are fluctuating.",1,https://api.osf.io/v2/files/5ad009c59c8e73000d1fd1c1/,916,https://engrxiv.org/7efw3/,10.31224/osf.io/7efw3,,2018-04-13T02:15:47.199873,2018-07-02T11:48:46.679161 | |
| p6h49,"Pyrolytic kinetics of coconut shell waste using Ramped PyrOx","Biomass pyrolysis is an efficient and economical conversion process. The kinetics of biomass conversion is still not fully understood mainly because this complex material is composed of numerous compounds with very different reactivities. In this work an inverse model is used to determine the nonparametric probability density function p(Ea) of activation energy (Ea) for coconut shell waste (CSW) pyrolysis via the Ramped PyrOx (RPO) method from the time-series and temperature-series mass conversion data. In this method, the degradation rates are described by inverting distributed activation energy model (DAEM). This method does not require p(Ea) to follow any particular parametric form furthermore the modelling results are independent of experimental conditions such as heating rates. The pyrolytic kinetics is modelled considering first-order degradation mechanism.",1,https://api.osf.io/v2/files/5aca84d2a5a60e000f458fde/,205,https://engrxiv.org/p6h49/,10.31224/osf.io/p6h49,,2018-04-08T21:16:12.424818,2018-07-02T11:48:07.834432 | |
| dq72t,"Evaluation of Self-Consolidating Concrete Robustness by Measuring Electrical Conductivity of Plastic Concrete","This paper is aimed to review robustness of Self-Consolidating Concrete (SCC) in term of resistance against static segregation and bleeding. SCC is a highly fluid and non-segregating concrete able to spread through even dense reinforcement and homogenously fill formwork without using any external mechanical consolidation. Due to field requirements, SCC should be able to sustain its desired fresh properties over a relatively long time (about two or three hours) making it more susceptible to segregation than conventional concrete. Although there are a couple | |
| of proposed test methods to evaluate SCC robustness, multi-electrodes electrical conductivity technique could be a reliable, non-destructive, inexpensive and simple test method to continuously monitor progress of hydration reactions (even indicating initial and final setting time) and stability (bleeding and both static and dynamic aggregate segregation) of plastic cement-based materials over the early-age period. In this paper, a brief review on fresh properties of SCC and static | |
| aggregate segregation has been taken place. Then, different methods for measuring concrete conductivity have been investigated. Afterward, some studies on evaluation of stability of cement-based materials and SCC have been reviewed. Finally, based on the literature, some recommendations for future works are introduced.",1,https://api.osf.io/v2/files/5ac2e77629ad60000e309571/,450,https://engrxiv.org/dq72t/,10.31224/osf.io/dq72t,,2018-04-03T02:35:55.501267,2018-07-02T11:48:04.983125 | |
| 6bn7x,"Analysis of Telecom Service Operation Behavior with Time Series","Operation of complex telecom services is a field that mixes technology, processes and teams. Despite the existence of detailed protocols and automation, the real behavior is hard to measure and predict. The human factor is a source of uncertainty, and this fact is of special relevance when facing stressful situations. Informal team working culture, time shifts or external pressure are main sources of change. In this research we use time series analysis as a statistical proxy to detect this kind of drift in teams that solve network failures if three live services: IPTV, Cloud Infrastructure and IoT. This task is | |
| known as incident management. This would provide not only a numerical evidence of the uncertainty in troubleshooting of digital services but also an | |
| assessment about the economic and operational impact of service releases. | |
| Changes in best fitting models may reflect different informal work cultures among the operation teams.",1,https://api.osf.io/v2/files/5ac24c49266c2a000dc77f67/,387,https://engrxiv.org/6bn7x/,10.31224/osf.io/6bn7x,,2018-04-02T15:35:59.011677,2018-07-02T11:48:04.179574 | |
| qsfp7,"Estimating turbulent kinetic energy and dissipation with internal flow loss coefficients","Estimating the turbulent kinetic energy at the nozzle outlet is necessary to model turbulent jet breakup. We identified errors in a model of nozzle turbulence developed by Huh et al. which made the model inaccurate. To develop an improved model, we derived a generalized form of the Bernoulli equation for non-cavitating flows. The equation can be used to estimate turbulent kinetic energy, k, and dissipation, ε, in internal flows given loss coefficients or friction factors and a turbulence model. The equation allows turbulent kinetic energy and dissipation to be estimated without computational fluid dynamics. The estimates can be used as-is where turbulent kinetic energy or dissipation are desired, or as a more accurate boundary condition for computational fluid dynamics. A model for fully developed pipe flow is developed and compared against experimental data. A nozzle turbulence model which could replace Huh et al.'s is also developed, but the model has not been validated due to a lack of experimental data.",1,https://api.osf.io/v2/files/5abdc359266c2a000fc231ef/,612,https://engrxiv.org/qsfp7/,10.31224/osf.io/qsfp7,,2018-03-30T04:59:47.525103,2018-07-02T13:32:13.328485 | |
| bhga9,"AHP INCONSISTENCY REDUCTION THROUGH TWO GREEDY ALGORITHMS APPLICATION","The purpose of this paper is to present two greedy algorithms that can improve the consistency of an AHP Matrix adjusting the original comparisons with discrete values. The first one aims to preserve the original pairwise comparisons as much as possible and the second one improves the consistency ratio as much as possible. Both algorithms were compared with other 11 methods, from the past and recent literature, through three numerical examples: one inconsistent matrix with 9 criteria, one with 8 criteria and the last one, a highly inconsistent matrix with 7 criteria. Our method performed better than all the other ones. The proposed method can be used independently from the techniques to derive the eigenvector, eigenvalue or the consistent ratio, and naturally, in order to make a sensible comparison, all methods were compared using the same techniques. The Conservative Algorithm solution, gains in quality because it can preserve most of the original information, however the consistent ratio value stays just below the consistency threshold, in the other hand, the Progressive Algorithm gains in quantity, because it aims to reduce the consistent ratio to zero or near zero. Our approach offers two types of solutions, that are fast and near optimal.",1,https://api.osf.io/v2/files/5abc442b266c2a000fc0e07e/,348,https://engrxiv.org/bhga9/,10.31224/osf.io/bhga9,,2018-03-29T01:45:53.392228,2018-07-02T13:32:11.209543 | |
| dytsv,"Study of Homogeneous Bubble Nucleation in Liquid Carbon Dioxide by a Hybrid Approach Combining Molecular Dynamics Simulation and Density Gradient Theory","A new method for predicting homogeneous bubble nucleation rates of pure compounds from vapor-liquid equilibrium (VLE) data is presented. It combines molecular dynamics simulation on the one side with density gradient theory using an equation of state (EOS) on the other. The new method is applied here to predict bubble nucleation rates in metastable liquid carbon dioxide (CO2). The molecular model of CO2 is taken from previous work of our group. PC-SAFT is used as an EOS. The consistency between the molecular model and the EOS is achieved by adjusting the PC-SAFT parameters to VLE data obtained from the molecular model. The influence parameter of density gradient theory is fitted to the surface tension of the molecular model. Massively parallel molecular dynamics simulations are performed close to the spinodal to compute bubble nucleation rates. From these simulations, the kinetic prefactor of the hybrid nucleation theory is estimated, whereas the nucleation barrier is calculated from density gradient theory. This enables the extrapolation of molecular simulation data to the whole metastable range including technically relevant densities. The results are tested against available experimental data and found to be in good agreement. The new method does not suffer from typical deficiencies of classical nucleation theory concerning the thermodynamic barrier at the spinodal and the bubble size dependence of surface tension, which is typically neglected in classical nucleation theory. In addition, the density in the center of critical bubbles and their surface tension is determined as a function of their radius. The usual linear Tolman correction to the capillarity approximation is found to be invalid.",1,https://api.osf.io/v2/files/5ab8e81a76e58c0010f9e274/,367,https://engrxiv.org/dytsv/,10.31224/osf.io/dytsv,10.1063/1.5022231,2018-03-26T19:06:30.759051,2018-07-02T11:45:30.230988 | |
| jrcm5,"Development of a Constant Volume Combustion Chamber for Material Synthesis","A constant volume combustion chamber (CVCC) was constructed to enable material synthesis procedures that are sensitive to temperature, pressure, and ambient species concentrations. Material synthesis processes require specific operating conditions in order to carry out the desired chemical reactions and property transformations, including the creation of paper-templated metals and nanoparticles. The 1.13 liter combustion chamber includes a test stand for conducting the material synthesis experiments. A premixed fuel-air mixture is ignited at a desired equivalence ratio in order to produce the required synthesis conditions. In comparison to furnaces and ovens, this approach provides greater flexibility for materials synthesis procedures. Computational modeling using adaptive mesh refinement, alongside preliminary experimental testing results, confirms that the CVCC can provide the appropriate conditions to synthesize paper-templated metals. The approach demonstrates that the CVCC can be a viable alternative to a furnace for use in materials synthesis applications.",1,https://api.osf.io/v2/files/5ab29ffbea370000138cfa74/,427,https://engrxiv.org/jrcm5/,10.31224/osf.io/jrcm5,,2018-03-21T18:12:42.222385,2018-07-02T11:45:24.531317 | |
| yxvga,"The Influence of Mixedness on Ignition for Hydrogen Direct Injection in a Constant Volume Combustion Chamber","The ignition behavior of the fuel in non-premixed turbulent combustion applications such as diesel engines and gas turbines is dependent on the mixing rate of the injected fuel and the working fluid. In this study, three-dimensional modeling of hydrogen injection into a constant volume combustion chamber (CVCC) is used to investigate the correlation between the mixing rate and important parameters of non-premixed combustion, such as ignition delay. Mixedness is quantified using mean spatial variation, which reflects the homogeneity of the mixture, and mean scalar dissipation, which represents the local gradients of the scalar. The case studies include nitrogen and argon as working fluids; injection velocities and nozzle diameters are varied for comparison. For consistency, the injected mass is kept constant and the injection duration is adjusted accordingly. The results indicate that a strong correlation exists between ignition delay and the defined mixedness parameters. The cases with higher mixedness values lead to a shorter ignition delay and a higher maximum flame temperature. Changing the working fluid and injection parameters can effectively modify the mixedness, and consequently affect the ignition onset and flame properties.",1,https://api.osf.io/v2/files/5ab29df8ea370000138cf7b4/,416,https://engrxiv.org/yxvga/,10.31224/osf.io/yxvga,,2018-03-21T18:05:19.460453,2018-07-02T11:45:24.495541 | |
| 9rgu6,"Linear static isogeometric analysis of an arbitrarily curved spatial Bernoulli-Euler beam","The present research is focused on the linear analysis of a spatial Bernoulli-Euler beam. Metrics of the reference and deformed configurations are rigorously defined with respect to the convective coordinate frame of reference. No higher order terms are neglected which makes the formulation ideally suited for analysis of arbitrarily curved spatial beams in the frame of finite (but small) strain theory. The well-known issue of nonorthogonality of local coordinate system at an arbitrary point of a spatial beam is solved by the introduction of a new coordinate line that is orthogonal to the normal plane of the beam axis at each point. Generalized coordinates of the present model are translations of the beam axis and the angle of twist of a cross section. Two different parameterizations of this angle are discussed and implemented. Both geometry and kinematics are described with the same set of NURBS functions, in line with the isogeometric approach. Numerical analysis proved that the theoretical considerations are correct. An in-depth analysis of convergence properties has confirmed the fact that models with the highest interelement continuity have an improved accuracy per DOF, for problems that result in a smooth structural response.",1,https://api.osf.io/v2/files/5ab2373afb9476000d2a4d28/,275,https://engrxiv.org/9rgu6/,10.31224/osf.io/9rgu6,,2018-03-21T10:51:23.895307,2018-07-02T11:45:23.624225 | |
| 8s59e,"Predicting wheel forces using bearing capacity theory for general planar loads","This paper assesses the applicability of bearing capacity theory for evaluating the forces generated on wheels operating on clay under steady rolling conditions. Considering recent advances in bearing capacity theory, namely with respect to the interaction diagrams developed for general loading, a theoretical model for computing the horizontal force or torque from fundamental input parameters such as the vertical force (weight), wheel diameter, and undrained shear strength of the soil is presented. The predictions are compared with existing analytical solutions and data from laboratory testing, and reasonable agreement is demonstrated. The foremost conclusion is that bearing capacity theory can be used to obtain reasonable predictions of wheel forces analytically under any operating condition (driven, braked, or towed), provided the contact length and so-called contact angle, which defines the position of the contact interface, can be estimated. Aside from providing a rigorous and highly convenient framework for evaluating wheel forces under arbitrary loading, the analysis enables a natural physical interpretation of the mobility problem.",1,https://api.osf.io/v2/files/5aaee11b80f2d3000d5999d4/,306,https://engrxiv.org/8s59e/,10.31224/osf.io/8s59e,10.1504/IJVP.2017.081276,2018-03-18T22:04:52.303674,2018-07-02T11:43:52.580416 | |
| qrv26,"Development of two models for estimation of rapid chloride penetration and investigation on effective parameters using Artificial Neural Networks (ANNs)","In this paper Artificial Neural Networks (ANNs) are employed to develop a model which could estimate the RCPT value of various mixtures according to the mix design parameters, age and surface resistivity of concrete specimens. Furthermore, sensitivity analysis is carried out on the best ANN model to determine the influence of each input on the concrete resistance to the rapid chloride penetration. 258 experimental datasets, resulted from 79 mix designs, were used as training data for ANN models; all of which prepared and tested in Concrete Technology and Durability Research Center of Amirkabir University of Technology (CTDRC). | |
| Another simplified model is proposed using linear regression analysis; which estimates the RCPT value simply according to surface resistivity measure. Finally, eight mixtures prepared in Building and Housing Research Center (BHRC) and six mixtures obtained from real-life projects, are employed to compare and validate the proposed models.",1,https://api.osf.io/v2/files/5aac175efb9476000e50e325/,313,https://engrxiv.org/qrv26/,10.31224/osf.io/qrv26,,2018-03-16T19:19:14.581649,2018-07-02T11:43:50.641775 | |
| m24kt,"Zero mean waveforms for neural stimulation","Biphasic charge balanced waveforms do not minimise faradaic processes at the electrode-electrolyte boundary and do not leave electrodes neutral with respect to the tissue. Superior waveforms for electrode health (and consequently tissue safety) exist and may also offer better performance in terms of power consumption and stimulation effectiveness within charge injection limits. This paper aims to provide intuitive insight into the limitations of biphasic waveforms and presents a simple method for assessing how well other waveforms will perform, as well as methods for designing waveforms to theoretically give zero residual voltage and zero net faradaic charge transfer.",1,https://api.osf.io/v2/files/5aac07c780f2d3000f9de4a8/,348,https://engrxiv.org/m24kt/,10.31224/osf.io/m24kt,,2018-03-16T18:21:04.621837,2018-07-02T11:43:50.602731 | |
| 5zq4r,"Investigation of Durability Pozzolanic Efficiency Factor by Means of Surface Resistivity Measurement","Supplementary cementitious materials (SCMs) are used in concrete due to their properties such as reduction of cement consumption, reducing cost, enhancing concrete compressive strength, and boost durability of concrete against aggressive environment. In this paper, durability pozzolanic efficiency factor of four types of raw natural pozzolans (natural Zeolite, Trass, Tuff, and Pumice) and a type of artificial pozzolans (Rice Husk Ash) with respect to durability of concrete against corrosion of the reinforcement are determined and compared with each other. For this purpose, surface electrical resistivity of 17 kinds of diverse concrete mixture design are measured at two ages (28 and 90 days) using the Wenner four probes apparatus. The results show that natural Zeolite has the highest durability pozzolanic efficiency factor; Trass and Rice Husk Ash are in the second rate, also Tuff and Pumice are in the last place.",1,https://api.osf.io/v2/files/5aabf42ffb947600115061e0/,294,https://engrxiv.org/5zq4r/,10.31224/osf.io/5zq4r,,2018-03-16T16:59:34.065977,2018-07-02T11:43:50.557664 | |
| 54gxe,"Combining an innovative measurement technique with accurate simulation to analyze engine friction","The entanglement of an innovative measurement technique with an accurate simulation yields in total a powerful tool to investigate the friction power losses in engines under realistic operating conditions, as will be discussed in the following. While the total engine friction power losses and the friction of the valve train are measured experimentally, the friction power losses of the crank train journal bearings are calculated using simulation. The result is in an efficient and powerful determination of the individual engine subassemblies under realistic operating conditions ranging from idle to full load operation. The presented method can be used to assess the efficiency of various friction reduction measures like cylinder deactivation, (ultra)low viscosity lubricants or coatings and won in 2014 the Innovation award of Magna Logistics Europe.",1,https://api.osf.io/v2/files/5aa7f7d76185de000e53fb0d/,308,https://engrxiv.org/54gxe/,10.31224/osf.io/54gxe,10.1007/s35146-016-0100-x,2018-03-13T16:18:35.267182,2018-07-02T11:43:47.339300 | |
| 5q394,"Current challenges and frontiers for the EHD simulation of journal bearings: a review","In this manuscript the authors discuss the current state of the art in the EHD-simulation of journal bearings in automotive applications like the internal combustion engine.",1,https://api.osf.io/v2/files/5aa1654d5b1b970015ba6d9e/,310,https://engrxiv.org/5q394/,10.31224/osf.io/5q394,10.4271/2016-01-1856,2018-03-08T16:36:22.942914,2018-07-02T11:42:10.256934 | |
| m7hsu,"An r-h Adaptive Kinematic Approach for 3D Limit Analysis","This paper explores a pathway for increasing efficiency in numerical 3D limit analysis through r-h adaptivity, wherein nodal positions (r) and element lengths (h) are successively refined. The approach uses an iterative, nested optimization procedure involving three steps: (1) determination of velocities for a fixed mesh of rigid, translational elements (blocks) using second-order cone programming; (2) adaptation of nodal positions using non-linear optimization (r adaptivity); and (3) subdivision of elements based on the magnitude of the velocity jumps (h adaptivity). Examples show that the method can compute reasonably accurate limit loads at relatively low computational cost.",1,https://api.osf.io/v2/files/5a9ee1b3f63187000e0f2300/,317,https://engrxiv.org/m7hsu/,10.31224/osf.io/m7hsu,,2018-03-06T18:51:33.206425,2018-07-02T11:42:08.455497 | |
| 35u7g,"Conditional damped random surface velocity model of turbulent jet breakup","A turbulent jet breakup model is derived using concepts from probability theory. Velocity fluctuations at the free surface are hypothesized to be the cause of turbulent jet breakup. We formalize this idea by treating the fluctuations as random variables, subject to damping from the free surface. In contrast to previous theories, we use a conditional ensemble average to determine quantities of interest because not all fluctuations produce droplets. An energy balance and a closure model are used to determine the Sauter mean diameter. Similar approaches are used to determine the breakup onset location, breakup length, and spray angle. A criteria for the transition to the turbulent atomization regime is derived under the hypothesis that the cause is a change in the minimum velocity from the Hinze scale to the Kolmogorov scale. To validate the model, we compiled data from previous experimental studies using long pipe nozzles. The little data for rough pipes was used to include turbulence intensity in our study.",1,https://api.osf.io/v2/files/5a9df35af63187000e0e9b6d/,425,https://engrxiv.org/35u7g/,10.31224/osf.io/35u7g,,2018-03-06T01:54:41.098116,2018-07-02T11:42:07.847227 | |
| dtxcm,"Torsional Dynamics Response of Shafts with Longitudinal and Circumferential Cracks ","Turbo generators shafts are manufactured through the extrusion process. This results in formation of weak planes along the extrusion process. It has been observed that large longitudinal cracks often form in these shafts before any circumferential cracks when these shafts are subjected to cyclic torsion due to electrical line faults. The presence of these cracks could severely compromise the shaft resonance frequencies. Dynamic response of shafts with longitudinal and circumferential cracks is investigated. The longitudinal cracked section of the shaft section is modeled as a shaft with reduced torsional rigidity. The torsional rigidity is obtained as a function of the crack depth. It was found for various shaft diameters, torsional rigidity could be represented as a function of crack depth/ shaft radius only. The circumferential cracked section is modeled as a torsional spring. The torsional spring constant has been obtained using fracture mechanics. It was found the resonance frequency of the shaft may be little affected by the presence of longitudinal crack. The resonance frequencies of the shaft with the circumferential crack depend on the crack length and location. The effects of crack surface interactions for both longitudinal and circumferential cracks were also investigated.",1,https://api.osf.io/v2/files/5a9af70ef63187000d0d7ae6/,177,https://engrxiv.org/dtxcm/,10.31224/osf.io/dtxcm,,2018-03-03T19:31:53.354861,2018-07-02T11:41:32.054703 | |
| s45qm,"Towards the Rapid Design of Engineered Systems Through Deep Neural Networks","The design of a system commits a significant portion of the final cost of that system. Many computational approaches have been developed to assist designers in the analysis (e.g., computational fluid dynamics) and synthesis (e.g., topology optimization) of engineered systems. However, many of these approaches are computationally intensive, taking significant time to complete an analysis and even longer to iteratively synthesize a solution. The current work proposes a methodology for rapidly evaluating and syn- thesizing engineered systems through the use of deep neural networks. The proposed methodology is applied to the analysis and synthesis of offshore structures such as oil platforms. These structures are constructed in a ma- rine environment and are typically designed to achieve specific dynamics in response to a known spectrum of ocean waves. Results show that deep learning can be used to accurately and rapidly synthesize and analyze off- shore structure.",1,https://api.osf.io/v2/files/5a9998e71af855000ffb0a1e/,589,https://engrxiv.org/s45qm/,10.31224/osf.io/s45qm,,2018-03-02T18:34:29.333609,2018-07-02T11:41:31.473622 | |
| n2hm3,"Data on the Design of Truss Structures by Teams of Engineering Students","This experiment was conducted in order to compare different approaches that human teams use to solve design problems that change dynamically during solving. Specifically, study participants were given the task of designing a truss structure (similar to a bridge spanning a chasm) in teams of three. At two points during design, the problem statement was changed unexpectedly, requiring participants to adapt. Two conditions were given different initial problem representations. During the study, every participant had access to a computer interface that allowed them to construct, test, and share solutions. The interface also made it possible to collect a step-by-step log of the actions made by participants during the study. This article contains data collected from 48 participants (16 teams). This data has been used previously in behavioral analyses, sequence-based analysis, and development of computational models.",1,https://api.osf.io/v2/files/5a96aa7391b689000da3010d/,308,https://engrxiv.org/n2hm3/,10.31224/osf.io/n2hm3,10.1016/j.dib.2018.02.078,2018-02-28T13:13:26.792604,2018-07-02T11:41:29.369746 | |
| tmg38,"Controlled three-dimensional polystyrene nano- and micro-structures fabricated by three-dimensional electrospinning","The combination of electrospinning with 3D printing technology opens new pathways for nano- and microfabrication, which can be applied in a wide range of application. This simple and inexpensive method was proven to fabricate 3D fibrous polystyrene structures with controlled morphology and micro to nano-fibre diameter. The controllable movement of the nozzle allows precise positioning of the deposition area of the fibres during electrospinning. A programmed circular nozzle pattern results in the formation of 3D polystyrene cylinder shapes with fibre diameters down to 560 nm. The assembly of the fibrous structures starts instantaneously, and a 4 cm tall and 5 cm wide sample can be produced within a 10-minute electrospinning process. The product exhibits high stability at ambient conditions. The shape, size, and thickness of fibrous polystyrene structures can be easily controlled by tuning the process parameters. It is assumed that the build-up of 3D fibrous polystyrene structure strongly depends on charge induction and polarization of the electrospun fibres.",1,https://api.osf.io/v2/files/5a9401d391b689000fa21da8/,175,https://engrxiv.org/tmg38/,10.31224/osf.io/tmg38,,2018-02-26T15:11:23.699073,2018-07-02T11:41:27.100405 | |
| 5hzkj,"Spontaneous formation of nanoparticles on electrospun fibers for fuel cell electrodes","Nanofibers spontaneously decorated with nanoparticles were synthesized by nozzle-free electrospinning, showcasing the latter as a novel, inexpensive and scalable method for depositing high-surface area composites. Layers of nanofibers of the intermediate-temperature proton conducting electrolyte cesium dihydrogen phosphate, (CsH2PO4, CDP), were deposited from homogeneous undersaturated solutions of CDP and polyvinylpyrrolidone (PVP), uniformly over large area substrates. Under certain conditions, the nanofibers develop CDP nanoparticles on their surface, which increases the exposed electrolyte surface area and ultimately enhances electrocatalytic performance. Indeed, fuel cell tests on cathodes made of processed nanoparticle-decorated CDP nanofibers produced higher cell voltage, as compared to state-of-the-art electrodes.",1,https://api.osf.io/v2/files/5a90778fda91d4000eb0e550/,274,https://engrxiv.org/5hzkj/,10.31224/osf.io/5hzkj,,2018-02-23T20:50:28.172998,2018-07-02T11:39:52.177123 | |
| rzm4g,"The role of hydrogen and fuel cells in the global energy system","Hydrogen technologies have experienced cycles of excessive expectations followed by disillusion. | |
| Nonetheless, a growing body of evidence suggests these technologies form an attractive option for | |
| the deep decarbonisation of global energy systems, and that recent improvements in their cost and | |
| performance point towards economic viability as well. This paper is a comprehensive review of the | |
| potential role that hydrogen could play in the provision of electricity, heat, industry, transport and | |
| energy storage in a low-carbon energy system, and an assessment of the status of hydrogen in being | |
| able to fulfil that potential. The picture that emerges is one of qualified promise: hydrogen is well | |
| established in certain niches such as forklift trucks, while mainstream applications are now forthcoming. | |
| Hydrogen vehicles are available commercially in several countries, and 225,000 fuel cell home heating | |
| systems have been sold. This represents a step change from the situation of only five years ago. This | |
| review shows that challenges around cost and performance remain, and considerable improvements are | |
| still required for hydrogen to become truly competitive. But such competitiveness in the medium-term | |
| future no longer seems an unrealistic prospect, which fully justifies the growing interest and policy | |
| support for these technologies around the world.",1,https://api.osf.io/v2/files/5a8d5983da91d4000eada71e/,833,https://engrxiv.org/rzm4g/,10.31224/osf.io/rzm4g,,2018-02-21T11:47:44.688722,2018-12-11T08:02:57.841951 | |
| w4a9y,"Effects of Fuel Sulfur Content and Dilution Conditions on Engine PM Emissions under Transient Conditions","The U.S. has introduced ultra low sulfur diesel fuel in 2007 and by 2010 will completely replace the current low-sulfur diesel fuel which has a sulfur content of less than 500 ppm. As a result, most diesel engines, including new and aged ones, are currently implementing ULSD. Thus, it is important to understand how ULSD will affect these engines’ emissions, especially under transient conditions when the load, speed, exhaust gas temperature, and primary dilution ratio change continuously. This study is to assess the effects of fuel sulfur content and aging condition on PM emissions under transient conditions. Combinations of fuels and primary dilutions were used. The primary dilution was accomplished by a CFV-CVS, a system which maintains proportional sampling throughout temperature excursions and is designed for engine emission certification. Data were collected by a Scanning Mobility Particle Sizer and an Engine Exhaust Particle Sizer for steady-state and transient testing, respectively. Although the steady-state results show reasonable agreement with previous studies, the transient results display significant discrepancy when ULSD and LSD were used with the high primary dilution ratio.",1,https://api.osf.io/v2/files/5a826031ab88da001212b042/,260,https://engrxiv.org/w4a9y/,10.31224/osf.io/w4a9y,,2018-02-13T03:55:24.427290,2018-07-02T11:39:06.959210 | |
| a3vyh,"Effects of a zeolite-selective catalytic reduction system on comprehensive emissions from a heavy-duty diesel engine","The effects of a zeolite urea-selective catalytic reduction aftertreatment system on a comprehensive spectrum of chemical species from diesel engine emissions were investigated in the present study. Representative samples were collected with a newly developed source dilution sampling system after an aging process designed to simulate atmospheric dilution and cooling conditions. Samples were analyzed with established procedures and compared between the measurements taken from a baseline heavy-duty diesel engine and also from the same engine equipped with the exhaust aftertreatment system. The results have shown significant reductions for nitrogen oxides, carbon monoxide, total hydrocarbons, polycyclic aromatic hydrocarbons, and organic carbon emissions. Additionally, less significant yet notable reductions were observed for particulate matter mass and metals emissions. Although two ionic compounds, sulfate and nitrate, displayed increased emission levels, the production of new species was not observed with the addition of the zeolite urea-selective catalytic reduction system joined with a downstream oxidation catalyst.",1,https://api.osf.io/v2/files/5a825eeeab88da001112b545/,196,https://engrxiv.org/a3vyh/,10.31224/osf.io/a3vyh,10.3155/1047-3289.58.10.1258,2018-02-13T03:46:29.936478,2018-07-02T11:39:06.921852 | |
| 8hznu,"Comparative analysis on the effects of diesel particulate filter and selective catalytic reduction systems on a wide spectrum of chemical species emissions","Two methods, diesel particulate filter (DPF) and selective catalytic reduction (SCR) systems, for controlling diesel emissions have become widely used, either independently or together, for meeting increasingly stringent emissions regulations world-wide. Each of these systems is designed for the reduction of primary pollutant emissions including particulate matter (PM) for the DPF and nitrogen oxides (NOx) for the SCR. However, there have been growing concerns regarding the secondary reactions that these aftertreatment systems may promote involving unregulated species emissions. This study was performed to gain an understanding of the effects that these aftertreatment systems may have on the emission levels of a wide spectrum of chemical species found in diesel engine exhaust. Samples were extracted using a source dilution sampling system designed to collect exhaust samples representative of real-world emissions. Testing was conducted on a heavy-duty diesel engine with no aftertreatment devices to establish a baseline measurement and also on the same engine equipped first with a DPF system and then a SCR system. Each of the samples was analyzed for a wide variety of chemical species, including elemental and organic carbon, metals, ions, n-alkanes, aldehydes, and polycyclic aromatic hydrocarbons, in addition to the primary pollutants, due to the potential risks they pose to the environment and public health. The results show that the DPF and SCR systems were capable of substantially reducing PM and NOx emissions, respectively. Further, each of the systems significantly reduced the emission levels of the unregulated chemical species, while the notable formation of new chemical species was not observed. It is expected that a combination of the two systems in some future engine applications would reduce both primary and secondary emissions significantly.",1,https://api.osf.io/v2/files/5a825d4ebab7f5000d443251/,212,https://engrxiv.org/8hznu/,10.31224/osf.io/8hznu,10.1021/es8004046,2018-02-13T03:41:27.455580,2018-07-02T11:39:06.887389 | |
| 8p4zj,"Comparative Study on Various Methods for Measuring Engine Particulate Matter Emissions","Studies have shown that there are a significant number of chemical species present in engine exhaust particulate matter emissions. Additionally, the majority of current world-wide regulatory methods for measuring engine particulate emissions are gravimetrically based. As modern engines produce increasingly lower particulate mass emissions, these methods become less and less stable and have high levels of measurement uncertainty. | |
| In this study, a characterization of mass emissions from engines with a range of particulate emission levels was made in order to gain a better understanding of the variability and uncertainty associated with common mass measurement methods, as well as how well these methods compare with each other. Two gravimetric mass measurement methods and a reconstructed mass method were analyzed as part of the present study. The results have shown that each of the mass measurement methods analyzed compare well at higher emission levels, but show significant disparity at the ultra-low emission levels commonly seen from modern diesel engines. Additionally, at ultra-low emission the uncertainty in the measurement becomes large, thus reducing confidence in the accuracy of the measurement. Based upon these findings, it would be difficult to justify a comparison between any two gravimetric measurement methods and it may be more appropriate to perform a reconstruction of the particulate mass due to a lower susceptibility to measurement error.",1,https://api.osf.io/v2/files/5a825b37bab7f5001044201c/,184,https://engrxiv.org/8p4zj/,10.31224/osf.io/8p4zj,10.4271/2008-01-1748,2018-02-13T03:30:57.489396,2018-07-02T11:39:06.851120 | |
| 54rz7,"Challenges and Opportunities in International Service Learning","Service learning, and specifically the work of organizations such as Engineers Without Borders USA, have become popular with universities looking to provide their students with applied educational opportunities which blend technical skills with a broader social mission and help the institution demonstrate its global impact. However, questions remain regarding the truly realized outcomes for students, as well as the unintended consequences that may be experienced by the partnering communities. This paper describes early results results from a four-year, mixed-method study which collected data through a combination of interviews and focus groups with members of the Engineers Without Borders USA organization, analysis and coding of completed project documentation, and observations and notes collected during a field visit to a project site. We conclude from our early data that students who are able (given sufficient resources) to fully participate in these type of projects do see positive benefits. However, barriers may prevent all students from having this opportunity. Further, the nature of student service learning projects inherently creates challenges for the communities that partner on these projects. Ongoing revisions to the Engineers Without Borders USA operating procedures may remedy some of the deficiencies, while researchers, participants, and institutions should continue to critically evaluate the impacts and outcomes of their work.",1,https://api.osf.io/v2/files/5a791f249f6c6e000f97aa4d/,371,https://engrxiv.org/54rz7/,10.31224/osf.io/54rz7,,2018-02-06T03:26:19.280480,2018-07-02T11:38:27.491456 | |
| sx7jc,"Lifting the Veil: Drawing Insights about Design Teams from a Cognitively-inspired Computational Model","Novel design methodologies are often evaluated through studies involving human designers, but such studies can incur a high personnel cost. It can also be difficult to isolate the effects of specific team or individual characteristics. This work introduces the Cognitively-Inspired Simulated Annealing Teams (CISAT) modeling framework, a platform for efficiently simulating and analyzing human design teams. The framework models a number of empirically demonstrated cognitive phenomena, thus balancing simplicity and direct applicability. This paper discusses the model's composition, and demonstrates its utility through simulating human design teams in a cognitive study. Simulation results are compared directly to the results from human designers. The CISAT model is also used to identify the most beneficial characteristics in the cognitive study.",1,https://api.osf.io/v2/files/5a788a1668ee49000e39fb5e/,349,https://engrxiv.org/sx7jc/,10.31224/osf.io/sx7jc,10.1016/j.destud.2015.06.005,2018-02-05T16:46:42.824662,2018-07-02T11:38:27.191951 | |
| qducz,"Rolling with the Punches: An Examination of Team Performance in a Design Task Subject to Drastic Changes","Designers must often create solutions to problems that exhibit dynamic characteristics. For instance, a client might modify specifications after design has commenced, or a competitor may introduce a new technology or feature. This paper presents a cognitive study that was conducted to explore the manner in which design teams respond to such situations. In the study, teams of undergraduate engineering students sought to solve a design task that was subject to two large, unexpected changes in problem formulation that were introduced during solving. High- and low-performing teams demonstrated very different approaches to solving the problem and overcoming the changes. The results indicate that there may exist a relationship between problem characteristics and fruitful solution strategies.",1,https://api.osf.io/v2/files/5a7888e89f6c6e000d98ce50/,369,https://engrxiv.org/qducz/,10.31224/osf.io/qducz,10.1016/j.destud.2014.10.001,2018-02-05T16:42:01.793717,2018-07-02T11:38:27.143947 | |
| b9znk,"A new clustering and visualization method to evaluate urban energy planning scenarios","The spatial visualization is a very useful tool to help decision-makers in the urban planning process to create future energy transition strategies, implementing energy efficiency and renewable energy technologies in the context of sustainable cities. Statistical methods are often used to understand the driving parameters of energy consumption but rarely used to evaluate future urban renovation scenarios. Simulating whole cities using energy demand softwares can be very extensive in terms of computer resources and data collection. A new methodology, using city archetypes is proposed, here, to simulate the energy consumption of urban areas including urban energy planning scenarios. The objective of this paper is to present an innovative solution for the computation and visualization of energy saving at the city scale. | |
| The energy demand of cities, as well as the micro-climatic conditions, are calculated by using a simplified 3D model designed as function of the city urban geometrical and physical characteristics. Data are extracted from a GIS database that was used in a previous study. In this paper, we showed how the number of buildings to be simulated can be drastically reduced without affecting the accuracy of the results. This model is then used to evaluate the influence of two set of renovation solutions. The energy consumption are then integrated back in the GIS to identify the areas in the city where refurbishment works are needed more rapidly. The city of Settimo Torinese (Italy) is used as a demonstrator for the proposed methodology, which can be applied to all cities worldwide with limited amount of information.",1,https://api.osf.io/v2/files/5a7830019f6c6e000d98776b/,439,https://engrxiv.org/b9znk/,10.31224/osf.io/b9znk,,2018-02-05T10:55:37.691531,2018-07-02T11:38:26.429540 | |
| rsxad,"Enhancement of Shear Transfer in Composite Deck with Mechanical Fasteners","Reinforced concrete construction and steel construction are two of the most common contemporary construction methods. Both methods make use of composite decks as floor systems and diaphragms. During the design of composite decks, the interaction between the steel deck and concrete slab is typically disregarded when calculating the strength of the composite di- aphragm due to lack of complete shear transfer, as existing practices such as stamping are not effective to provide substantial composite action. This conservative assumption essentially results in non-efficient use of material. This paper presents a method for ensuring shear transfer through the use of conventional sheet metal screws, driven through the corrugated steel deck and embedded in the fresh concrete. This method is proposed for use in the field between formed steel beams. Both experimental and analytical stud- ies support an increase in strength with the addition of embedded fasteners. Further, experimental results indicate an additional increase in strength with the addition of synthetic reinforcing fibers. The increase in strength with the addition of the fasteners is on the order of 100%. When fasteners are already in use, the addition of synthetic reinforcing fibers can increase strength on the order of 10%. The ultimate deflection of enhanced deck is comparable to deck tested without fasteners, but the initial stiffness of enhanced deck is much higher.",1,https://api.osf.io/v2/files/5a7626b09f6c6e001095f394/,247,https://engrxiv.org/rsxad/,10.31224/osf.io/rsxad,10.1016/j.engstruct.2015.01.046,2018-02-03T21:18:53.600454,2018-07-02T11:38:24.490016 | |
| jbw3z,"Combining Multi-body Dynamics and Potential Flow Simulation Methods to Model a Wave Energy Converter","Numerical simulations that predict the dynamics and performance of wave energy converters (WECs) require the simulation of complex fluid-structure interactions between a WEC device and the wave environment. Navier- Stokes computational fluid dynamics (CFD) simulations and fully time-domain boundary integral equation methods (BIEMs) can be coupled with multi-body dynamics solvers to simulate these problems. However, the computational resources that are required to perform these types of high-fidelity simulations are significant, precluding the use of CFD and time-domain BIEM for design optimization. One method for reducing the numerical complexity of WEC simulations is to model the hydrodynamics using frequency- domain simulations, while model the dynamic motion of the WEC device in the time-domain using multi-body dynamics methods. | |
| The primary objective of the work presented herein is to develop such a numerical tool using the multi-body solver SimMechanics and the frequency-domain hydrodynamics code WAMIT. The numerical tool was developed so that WEC devices comprised of arbitrarily connected bodies, power-take-off (PTO) systems, and mooring systems can be simulated in operational sea states, where the wave environment can be modeled under linear assumptions. The remainder of this paper describes the development and verification of the numerical tool.",1,https://api.osf.io/v2/files/5a74e92368ee49001037e6e6/,414,https://engrxiv.org/jbw3z/,10.31224/osf.io/jbw3z,,2018-02-02T22:43:47.352532,2018-07-02T11:38:22.136022 | |
| 34e9h,"Influence of Crosslinking on the Mechanical Behavior of 3D Printed Alginate Scaffolds: Experimental and Numerical Approaches","Tissue scaffolds fabricated by three-dimensional (3D) bioprinting are attracting considerable | |
| attention for tissue engineering applications. Because the mechanical properties of hydrogel | |
| scaffolds should match the damaged tissue, changing various parameters during 3D bioprinting | |
| has been studied to manipulate the mechanical behavior of the resulting scaffolds. Crosslinking | |
| scaffolds using a cation solution (such as CaCl2) is also important for regulating the mechanical | |
| properties, but has not been well documented in the literature. Here, the effect of varied | |
| crosslinking agent volume and crosslinking time on the mechanical behavior of 3D bioplotted | |
| alginate scaffolds was evaulated using both experimental and numerical methods. Compression | |
| tests were used to measure the elastic modulus of each scaffold, then a finite element model was | |
| developed and a power model used to predict scaffold mechanical behavior. Results showed that | |
| crosslinking time and volume of crosslinker both play a decisive role in modulating the mechanical | |
| properties of 3D bioplotted scaffolds. Because mechanical properties of scaffolds can affect cell | |
| response, the findings of this study can be implemented to modulate the elastic modulus of | |
| scaffolds according to the intended application.",1,https://api.osf.io/v2/files/5a735f350d9c910011b0af58/,424,https://engrxiv.org/34e9h/,10.31224/osf.io/34e9h,10.1016/j.jmbbm.2018.01.034,2018-02-01T18:48:44.608930,2018-07-02T11:37:29.092965 | |
| c86hb,"A parametric tool to evaluate the environmental and economic feasibility of decentralized energy systems.","A simulation tool is developed to make a comprehensive techno-economic and environmental assessment of a case study under different scenarios. Different capacity of solar and storage technologies are considered. The model calculates the levelized cost of electricity, the autonomy level and the CO2 emissions. We demonstrate that the economic profitability of solar and battery system is in very good agreement with HOMER and the autonomy level is validated by using a simulation tool created by SI-REN. We show that combining solar PV | |
| with battery system doesn't bring additional autonomy to the model for Geneva considering the present market prices for batteries and seasonal changes in solar energy potential. The validated tool is then extended to include the thermal demand and generation by adding heat pumps and solar thermal. The availability of thermal storage at a large scale and the generation over a neighbourhood are shown to increase the autonomy of the neighbourhood. | |
| Finally, multiple scenarios are also run by changing the input parameters to perform a sensitivity analysis of these parameters on the performance of the model. Under the assumptions of the model, to foster investments in solar PV and battery installations, falling investments costs seem necessary for the future.",1,https://api.osf.io/v2/files/5a72d16df4fc5d0010ae1ddf/,420,https://engrxiv.org/c86hb/,10.31224/osf.io/c86hb,,2018-02-01T08:46:12.574921,2018-07-02T11:37:27.666854 | |
| 8k2cr,"Heterogeneous Simulated Annealing Teams: An Optimizing Search Algorithm Inspired by Engineering Design Teams","Although insights uncovered by design cognition are often utilized to develop the methods used by human designers, using such insights to inform computational methodologies also has the potential to improve the performance of design algorithms. This paper uses insights from research on design cognition and design teams to inform a better simulated annealing search algorithm. Simulated annealing has already been established as a model of individual problem solving. This paper introduces the Heterogeneous Simulated Annealing Team (HSAT) algorithm, a multi-agent simulated annealing algorithm. Each agent controls an adaptive annealing schedule, allowing the team develop heterogeneous search strategies. Such diversity is a natural part of engineering design, and boosts performance in other multi-agent algorithms. Further, interaction between agents in HSAT is structured to mimic interaction between members of a design team. Performance is compared to several other simulated annealing algorithms, a random search algorithm, and a gradient-based algorithm. Compared to other algorithms, the team-based HSAT algorithm returns better average results with lower variance.",1,https://api.osf.io/v2/files/5a71f9790e580c000c192786/,218,https://engrxiv.org/8k2cr/,10.31224/osf.io/8k2cr,,2018-01-31T17:16:51.244307,2018-07-02T11:37:26.366063 | |
| fyr6s,"Fairness and Manipulation: An Empirical Study of Arrow's Impossibility Theorem","The design process often requires work by teams, rather than individuals. During these times it is likely that situations will arise in which members of a team have different opinions, yet a group decision must still be made. Unfortunately, Arrow’s Impossibility Theorem indicates that there is no method for aggregating group preferences that will always satisfy a small number of “fair” conditions. This work seeks to identify methods of combining individual preferences that can come close to satisfying Arrow’s conditions. Experiential conjoint analysis was used to obtain empirical utility functions for drinking mug designs. A number of functions for constructing group preference were then analysed using both empirical conjoint preferences and randomly generated preferences. This analysis involved checking each of Arrow’s conditions, as well as computing the likelihood that a method will be susceptible to manipulation by a dishonest individual. Based on the results, methods that should be used to aggregate group preference in practice are recommended.",1,https://api.osf.io/v2/files/5a71f8110e580c000c1925a4/,260,https://engrxiv.org/fyr6s/,10.31224/osf.io/fyr6s,,2018-01-31T17:10:29.133194,2018-07-02T11:37:26.263623 | |
| k6rxa,"A review on the artificial intelligence algorithms for the recognition of Activities of Daily Living using sensors in mobile devices","The automatic recognition of Activities of Daily Living (ADL) with a multi-sensor mobile device that can acquire different types of sensors' data, and rely on the use of machine learning methods to handle the recognition of ADL with reliable accuracy. This paper focuses on the literature review of the existing methods to make the identification of ADL in order to assess the efficiency of the different methods for the identification of ADL and their environments using off-the-shelf mobile devices. Data acquired from several sensors can be used for the identification of ADL, where the motion, magnetic and location sensors handle the recognition of activities with movement, and the acoustic sensors handle the recognition of activities related with the environment. Therefore, the main purpose of this study is to present a review of the machine learning methods already used on this field, relating them with the accuracy and number of ADL recognized.",1,https://api.osf.io/v2/files/5a706498198462000fb8a987/,362,https://engrxiv.org/k6rxa/,10.31224/osf.io/k6rxa,,2018-01-30T12:31:05.281512,2018-07-02T11:37:24.064639 | |
| zudhe,"Eliciting Configuration Design Heuristics with Hidden Markov Models","Configuration design problems, characterized by the selection and assembly of components into a final desired solution, are common in engineering design. Although a variety of theoretical approaches to solving configuration design problems have been developed, little research has been conducted to observe how humans naturally attempt to solve such problems. This work mines the data from a cognitive study of configuration design to extract helpful design heuristics. The extraction of these heuristics is automated through the application of hidden Markov models. Results show that, for a truss configuration problem, designers proceed through four procedural states in solving configuration design problems, transitioning from topology design to shape and parameter design. High-performing designers are distinguished by their opportunistic tuning of parameters early in the process, enabling a heuristic search process similar to the A* search algorithm.",1,https://api.osf.io/v2/files/5a6fc3c0e37c06000ffa0846/,239,https://engrxiv.org/zudhe/,10.31224/osf.io/zudhe,,2018-01-30T01:02:56.060625,2018-07-02T11:37:23.503060 | |
| vfwme,"Multi-Objective Optimization and Scenario-based Robustness Analysis of the MoneyMaker Hip Pump","Water-lifting technologies for irrigation have significant potential to increase agricultural yields and stimulate economic growth in rural areas of the developing world. Human-powered water pumps have been used with great success in this rapidly developing market. KickStart's MoneyMaker Hip Pump is a human-powered water pump with additional design features that make it lightweight and portable for use in remote fields in several countries throughout Africa. This work first applied numerical optimization techniques to the design of the MoneyMaker Hip Pump and offers further improvements to its design. Deterministic multi-objective optimization methods were employed to maximize the flow rate of the pump, maximize the pumping height of water, and minimize cost. Following optimization, the robustness of the optimized pump design was analyzed under several modified scenarios, including fouling of the hoses and a decrease in operator power due to fatigue or aging. The set of cost-optimized pump designs was then compared to a second set of optimal designs that was found using material volume as a simplified proxy for the cost objective function. Findings indicate that several technical improvements can be made to the current MoneyMaker Hip Pump design to reduce cost by up to 37% without affecting water flow rate, or increase water flow rate by up to 88% without increasing cost. The numerical model was validated through physical experimentation of the MoneyMaker Hip Pump, and design alterations to reduce cost were experimentally shown to maintain pump performance.",1,https://api.osf.io/v2/files/5a6fbe491984620010b7fa36/,341,https://engrxiv.org/vfwme/,10.31224/osf.io/vfwme,10.1016/j.deveng.2018.01.001,2018-01-30T00:40:45.607841,2018-07-02T11:37:23.460554 | |
| yh2k6,"Selection of Artificial Muscle Actuators for a Continuum Manipulator","Artificial muscle actuators have become a popular choice as actuation units for robotic applications, particularly in the growing area of soft robotics. The precise specification of an artificial muscle actuator for a particular application requires the consideration of several parameters that work together to achieve the performance characteristics of the actuator. This paper explores the specification of artificial muscle actuator parameters by presenting and applying the analytical description of the actuator, simulation by finite element method for investigating material stresses under a wide variety of configurations, and a specific parameter selection process. This is followed by an experimental validation using an example actuator to compare against the predicted actuator performance. Some discussion of appropriateness of this type of actuator as a candidate solution for use in the example application of a dexterous continuum manipulator is included. | |
| This work has been submitted to the IEEE for possible publication.",1,https://api.osf.io/v2/files/5a66b208630114000caf2ae4/,336,https://engrxiv.org/yh2k6/,10.31224/osf.io/yh2k6,,2018-01-23T04:02:37.897500,2018-07-02T11:36:43.079904 | |
| sj9w6,"User Testing of a Continuum Manipulator for Assistive Technology","The application of continuum manipulators as assistive robots is discussed and tested through the use of Bendy ARM, a tendon-driven continuum manipulator prototype. Two rounds of user testing were completed to evaluate the potential of this robot to aid disabled individuals in the completion of activities of daily living. In the first round of user testing, 14 able-bodied subjects successfully completed the prescribed task (pick-and-place) using multiple control schemes after being given a brief introduction and one minute of practice with each scheme. In the second round of user testing, subjects chosen from the first round of testing (n = 3) demonstrated between 29.45 and 48.91 percent improvement in completion time across three sessions (twelve trials total) of a peg-in-hole task, and between 8.39 and 33.81 percent improvement across two sessions (six trials total) of a task involving opening and closing a drawer. Based on these results, it is posited that continuum manipulators merit further consideration as a safer and more cost-effective alternative to existing commercially available assistive robotic manipulators.",1,https://api.osf.io/v2/files/5a5e65f0f8a0b5000ff0e665/,359,https://engrxiv.org/sj9w6/,10.31224/osf.io/sj9w6,,2018-01-16T20:57:35.787518,2018-07-02T11:35:29.109864 | |
| 87n39,"Pulse Width Modulation (PWM) Signals Based on Spiking Neuronal Networks","This paper proposes a digital construction of Pulse | |
| Width Modulation (PWM) signals based on the Izhikevich neuron | |
| model using a Field Programmable Gate Array (FPGA) platform. | |
| The signals are intended for use in diverse electronics applications | |
| such as robotics and power converters. A spiking pattern was | |
| used to generate the input data and produce the PWM signals. | |
| A comparator was used to compare between the spiking pattern | |
| data and DC level parameters. The results validate that the | |
| proposed hardware can reproduce PWM signals with duty cycles | |
| from 0% to 100%.",1,https://api.osf.io/v2/files/5a58144fff20fa000ee76428/,853,https://engrxiv.org/87n39/,10.31224/osf.io/87n39,10.1109/ICSIPA.2017.8120602,2018-01-12T01:55:18.091253,2018-07-02T13:30:51.765485 | |
| 7xch2,"A digital implementation of 2D Hindmarsh–Rose neuron","Different architectures and techniques have | |
| developed in the neuromorphic field to mimic and | |
| investigate the activity of biological neural networks. | |
| This paper presents a set of piece-wise linear approximations | |
| of a two-dimensional Hindmarsh–Rose neuron | |
| model for digital circuit implementation to achieve | |
| higher speeds and lower hardware costs in large-scale | |
| implementation of the biological neural networks. The | |
| performance of the model was evaluated with a time | |
| domain signal error. Synthesis and hardware implementation | |
| on a field-programmable gate array, as a | |
| proof of concept, indicates that the proposed model | |
| reproduces several neuronal behaviors similar to the | |
| original model with higher performance and considerably | |
| lower implementation costs.",1,https://api.osf.io/v2/files/5a581231ff20fa000fe768d0/,449,https://engrxiv.org/7xch2/,10.31224/osf.io/7xch2,,2018-01-12T01:48:22.143834,2018-07-02T13:30:51.728676 | |
| ag4jv,"Design and Implementation of a GPS based Personal Tracking System","Tracking based applications have been quite popular in recent times. Most of them have been limited to commercial applications such as vehicular tracking (e.g tracking of a train etc). However, not much work has been done towards design of a personal tracking system. Our Research work is an attempt to design such personal tracking system. In this paper, we have shared glimpses of | |
| our research work. | |
| The objective of our research project is to design & develop a system which is capable of tracking and monitoring a person, object or any other asset of importance (called as target). The system uses GPS to determine the exact position of the target. The target is aided with a compact handheld device which consists of a GPS receiver and GSM modem. GPS receiver obtains location coordinates (viz. Latitude & Longitude) from GPS satellites. The location information in NMEA format is decoded, formatted and sent to control station, through a GSM modem. Due to use of Open CPU development platform, no external Microcontroller is required, with additional advantage of compact size product, reduced design & development time and reduced cost. | |
| Thus, the proposed system is able to track the accurate | |
| location of target. This system finds applications in tracking old-age people, tracking animals in forest, tracking delivery of goods etc. Our final designed system is a small-size compact l.S""X3.7S"" Tracker system with position accuracy error <30m (100 feet).",1,https://api.osf.io/v2/files/5a4cac4c3580f5000e89f3b9/,601,https://engrxiv.org/ag4jv/,10.31224/osf.io/ag4jv,,2018-01-03T10:19:57.511558,2018-07-02T11:33:30.832107 | |
| vn72w,"Numerical investigation of the mechanical properties of the additive manufactured bone scaffolds fabricated by FDM: the effect of layer penetration and post-heating","In recent years, thanks to additive manufacturing technology, researchers have gone towards the optimization of bone scaffolds for the bone reconstruction. Bone scaffolds should have appropriate biological as well as mechanical properties in order to play a decisive role in bone healing. Since the fabrication of scaffolds is time consuming and expensive, numerical methods are often utilized to simulate their mechanical properties in order to find a nearly optimum one. Finite element analysis is one of the most common numerical methods that is used in this regard. In this paper, a parametric finite element model is developed to assess the effects of layers penetration׳s effect on inter-layer adhesion, which is reflected on the mechanical properties of bone scaffolds. To be able to validate this model, some compression test specimens as well as bone scaffolds are fabricated with biocompatible and biodegradable poly lactic acid using fused deposition modeling. All these specimens are tested in compression and their elastic modulus is obtained. Using the material parameters of the compression test specimens, the finite element analysis of the bone scaffold is performed. The obtained elastic modulus is compared with experiment indicating a good agreement. Accordingly, the proposed finite element model is able to predict the mechanical behavior of fabricated bone scaffolds accurately. In addition, the effect of post-heating of bone scaffolds on their elastic modulus is investigated. The results demonstrate that the numerically predicted elastic modulus of scaffold is closer to experimental outcomes in comparison with as-built samples.",1,https://api.osf.io/v2/files/5a46fd58b794960010b0da4f/,872,https://engrxiv.org/vn72w/,10.31224/osf.io/vn72w,10.1016/j.jmbbm.2016.01.031,2017-12-30T02:53:25.841293,2018-07-02T11:33:26.480151 | |
| y4pfe,"Ultimate behaviour of cladding assemblages in industrial buildings","Profiled steel sheeting is widely used as cladding systems in industrial buildings. These systems are normally composed of thin-walled cold-formed steel profiles attached to steel purlins, or side-rails, which are connected to the column elements by means of simple fastener arrangements. Extensive research has been carried out on the response of cold-formed cladding systems under out of plane loading and codified recommendations are available to estimate their resistance under serviceability and ultimate limit states for the purpose of conventional design verifications. Attention has also been placed recently on quantifying the degree of rotational flexibility offered by purlin-sheeting systems. Nevertheless, the ultimate response of such configurations involves complex interactions within the cladding-purlin-connection assemblage that need to be carefully examined in order to assess and quantify the large deformation response. | |
| The study reported in this paper focuses on the inelastic response of industrial cladding systems which are designed and detailed according to conventional European practice. Selected results from a series of quasi-static tests performed within a wider collaborative project aimed at assessing the local and global static and dynamic behaviour of industrial building systems are presented. Due to the comparatively more robust response of typical industrial frame elements, the tests focus on the performance of cladding-purlin-column assemblages. The test layout and boundary conditions are described and the discussion is centred on key structural response parameters, namely stiffness, strength and failure conditions. Preliminary numerical assessments carried out with a view to providing further analytical and design studies are also outlined.",1,https://api.osf.io/v2/files/5a4557bf67d19e000e6a9bfb/,433,https://engrxiv.org/y4pfe/,10.31224/osf.io/y4pfe,,2017-12-28T20:52:15.636920,2018-07-02T11:31:08.623584 | |
| yt6w7,"Combinational processing of 3D printing and electrospinning of hierarchical poly(lactic acid)/gelatin-forsterite scaffolds as a biocomposite: Mechanical and biological assessment","In this research, hierarchical scaffolds including poly(lactic acid) (PLA) micro struts and nanocomposite gelatin-forsterite fibrous layers were developed using fused deposition modeling (FDM) and electrospinning (ES), respectively. Briefly, geometrically various groups of pure PLA scaffolds (interconnected pores of 230 to 390 μm) were fabricated using FDM technique. After mechanical evaluation, ES technique was utilized to develop gelatin-forsterite nanofibrous layer. To study these scaffolds, scanning electron microscopy (SEM), Fourier transform infrared spectroscopy, and uniaxial compression tests were performed. Furthermore, bioactivity of the scaffolds was evaluated by immersing in the simulated body fluid and apatite formation on the surface of the scaffolds was investigated. Results depicted that elastic modulus of PLA/gelatin-forsterite scaffolds, fabricated by a combinational approach, was significantly higher than that of pure one (about 52%). SEM images showed the formation of calcium phosphate-like precipitates on the surface of these scaffolds, confirming the effects of nanocomposite fibrous layer on the improved bioactivity of the scaffolds. Regarding the obtained biological as well as mechanical properties, the developed bio-composite scaffolds can be used as a biocompatible candidate for bone tissue regeneration.",1,https://api.osf.io/v2/files/5a415a41b794960013ae416f/,168,https://engrxiv.org/yt6w7/,10.31224/osf.io/yt6w7,10.1016/j.matdes.2017.07.051,2017-12-25T20:16:44.211540,2018-07-02T11:31:06.273454 | |
| zp7nd,"An Adaptive Genetic Algorithm for Solving N-Queens Problem","In this paper a Meta-heuristic approach for solving the N-Queens Problem is introduced to find the best possible solution in a reasonable amount of time. Genetic Algorithm is used with a novel fitness function as the Meta-heuristic. The aim of N-Queens Problem is to place N queens on an N x N chessboard, in a way so that no queen is in conflict with the others. Chromosome representation and genetic operations like Mutation and Crossover are described in detail. Results show that this approach yields promising and satisfactory results in less time compared to that obtained from the previous approaches for several large values of N.",1,https://api.osf.io/v2/files/5a3c01235a9350000da648b3/,518,https://engrxiv.org/zp7nd/,10.31224/osf.io/zp7nd,,2017-12-21T18:49:55.216506,2018-07-02T11:31:03.143239 | |
| 6jcd7,"Earthmoving through the Lens of Geotechnical Engineering","Earthmoving machines of varying sophistication, ranging from the simple garden spade to the hydraulic excavator, have evolved considerably over the centuries, but the scientific understanding of earthmoving processes lags considerably behind the technology. Historically much effort has been directed towards aspects of the machine, whereas relatively little attention has been given to the soil. For this reason, the problem has primarily engaged the interest of mechanical engineers. This paper provides a brief overview of the state of the art in analytical and numerical modeling, as well as some of the significant challenges that have yet to be overcome. It concludes with a description of the research program at Northwestern University, which includes analytical and numerical modeling of earthmoving processes and experiments completed using a new experimental facility. The preliminary results shown in the paper highlight key features of earthmoving processes and the potential for contributions from geotechnical engineers.",1,https://api.osf.io/v2/files/5a310633fdec39000f618122/,401,https://engrxiv.org/6jcd7/,10.31224/osf.io/6jcd7,,2017-12-13T10:58:40.798504,2018-07-02T11:29:44.445803 | |
| 5t2ku,"The Transformational Effects of Applying Systems Engineering in Laboratory Scientific Research","Through case study analysis of physicists working in quantum systems, we establish that knowledge of Systems Engineering (SE) will benefit scientists by ensuring that experimental apparatus is robust and fully meets the experiment requirements. We suggest a paradigm shift in the training of early career research scientists to ensure they have a strong appreciation of the systems approach and experience of applying SE techniques. Two case studies were used: the first was a detailed analysis of increasing levels of SE in the development of a 3D-printer for fabricating superconducting nano-circuitry. Applying SE techniques improved record keeping, reduced the risk of failure modes and took better account of future development through which scientific discovery may be exploited in practical devices. The second case study focused on a group of 30 quantum physics PhD students undertaking a short-course in basic SE, and used their opinions to check and add confidence to the findings of the first case study. A variety of tools were used in both studies and, in both cases, the Functional Failure Means Effects Analysis (FFMEA) technique was considered to be most useful. Recommendations are made for the future training of early career scientists to include some light-weight Systems Engineering.",1,https://api.osf.io/v2/files/5a2a7e17e08e9b000e9ab972/,539,https://engrxiv.org/5t2ku/,10.31224/osf.io/5t2ku,,2017-12-08T12:09:40.726224,2018-07-02T11:28:44.369385 | |
| 7vpfn,"Spectral Unmixing With Perturbed Endmembers","We consider the problem of supervised spectral unmixing with a fully-perturbed linear mixture model where the given endmembers, as well as the observations of the spectral image, are subject to perturbation due to noise, error, mismatch, etc. We calculate the Fisher information matrix and the Cramer-Rao lower bound associated with the estimation of the abundance matrix in the considered fully-perturbed linear spectral unmixing problem. We develop an algorithm for estimating the abundance matrix by minimizing a constrained and regularized maximum-loglikelihood objective function using the block coordinate-descend iterations and the alternating direction method of multipliers. We analyze the convergence of the proposed algorithm theoretically and perform simulations with real hyperspectral image datasets to evaluate its performance. The simulation results corroborate the efficacy of the proposed algorithm in mitigating the adverse effects of perturbation in the endmembers.",1,https://api.osf.io/v2/files/5a288f9f3ce6c0000ecd25c9/,642,https://engrxiv.org/7vpfn/,10.31224/osf.io/7vpfn,,2017-12-07T00:57:46.745615,2018-07-02T11:28:41.971433 | |
| 7wmha,"Application of a Rectified Linear Unit (ReLU) Based Artificial Neural Network to Cetane Number Predictions","Due to the high cost and time required to synthesize alternative fuel candidates for comprehensive testing, an Artificial Neural Network (ANN) can be used to predict fuel properties, allowing researchers to preemptively screen desirable fuel candidates. However, the accuracy of an ANN is limited by its error, measured by the root mean square error (RMSE), standard deviation, and r-squared values derived from a given input database. The present work improves upon an existing model for predicting the Cetane Number (CN) by changing the neuron activation function of the ANN from sigmoid to rectified linear unit (ReLU). This change to the ANN’s architecture provides an increase in accuracy by reducing the RMSE by 21.4% (1.35 CN units), the average standard deviation across models by 28%, and increasing the r-squared value by 0.0492 across a wide range of molecular structures. Additionally, by using the ReLU activation function, input data is not required to be normalized, which reduces the likelihood of an inaccurate prediction on future fuel candidates which may have input parameters outside the range of normalization. Increasing the accuracy of the predictive ANN in this way will allow researchers to obtain more accurate fuel property predictions for promising fuel candidates.",1,https://api.osf.io/v2/files/5a26d0b386b219000e8aec93/,490,https://engrxiv.org/7wmha/,10.31224/osf.io/7wmha,10.1115/ICEF2017-3614,2017-12-05T17:04:00.792571,2018-07-02T11:27:27.623613 | |
| zuav2,"Dispensing-Based Bioprinting of Hybrid Scaffolds with Vessel-like Channels for Tissue Engineering Applications – A Brief Review","Over the past two decades, significant progress has been achieved in the field of tissue engineering (TE) to restore/repair damaged tissues or organs and, in this regard, scaffolds made from biomaterials have played a critical role. Notably, recent advances in biomaterials and three-dimensional (3D) printing have enabled the manipulation of two or more biomaterials of distinct, yet complementary, mechanical and/or biological properties to form so-called hybrid scaffolds mimicking native tissues. Among various biomaterials, hydrogels synthesized to incorporate living cells and/or biological molecules have dominated due to their hydrated tissue-like environment. Moreover, dispensing-based bioprinting has evolved to the point that it can now be used to create hybrid scaffolds with complex structures. However, the complexities associated with multi-material bioprinting and synthesis of hydrogels used for hybrid scaffolds pose many challenges for their fabrication. This paper presents a brief review of dispensing-based bioprinting of hybrid scaffolds for TE applications. The focus is on the design and fabrication of hybrid scaffolds, including imaging techniques, potential biomaterials, physical architecture, mechanical properties, cell viability, and the importance of vessel-like channels. The key issues and challenges for dispensing-based bioprinting of hybrid scaffolds are also identified and discussed along with recommendations for future research directions. Addressing these issues will significantly enhance the design and fabrication of hybrid scaffolds to and pave the way for translating them into clinical applications.",1,https://api.osf.io/v2/files/5a1ef05c9ad5a102722a2264/,691,https://engrxiv.org/zuav2/,10.31224/osf.io/zuav2,10.1016/j.jmbbm.2017.11.037,2017-11-29T23:24:37.685079,2018-07-02T11:25:51.134418 | |
| rv65c,"Image Registration Techniques: A Survey","Image Registration is the process of aligning two or more images of the same scene with reference to a particular image. The images are captured from various sensors at different times and at multiple view-points. Thus to get a better picture of any change of a scene/object over a considerable period of time image registration is important. Image registration finds application in medical sciences, remote sensing and in computer vision. This paper presents a detailed review of several approaches which are classified accordingly along with their contributions and drawbacks. The main steps of an image registration procedure are also discussed. Different performance measures are presented that determine the registration quality and accuracy. The scope for the future research are presented as well.",1,https://api.osf.io/v2/files/5a1dd539594d90026fd92b88/,478,https://engrxiv.org/rv65c/,10.31224/osf.io/rv65c,,2017-11-28T21:31:55.812752,2018-07-02T11:25:48.557193 | |
| a6zmp,"A novel contact interaction formulation for voxel-based micro-finite-element models of bone","Voxel-based micro-finite-element (μFE) models are used extensively in bone mechanics research. A major disadvantage of voxel-based μFE models is that voxel surface jaggedness causes distortion of contact-induced stresses. Past efforts in resolving this problem have only been partially successful; i.e., mesh smoothing failed to preserve uniformity of the stiffness matrix, resulting in (excessively) larger solution times, whereas reducing contact to a bonded interface introduced spurious tensile stresses at the contact surface. This paper introduces a novel ‘smooth’ contact formulation that defines gap distances based on an artificial smooth surface representation while using the conventional penalty contact framework. Detailed analyses of a sphere under compression demonstrated that the smooth formulation predicts contact-induced stresses more accurately than the bonded contact formulation. When applied to a realistic bone contact problem, errors in the smooth contact result were under 2%, whereas errors in the bonded contact result were up to 42.2%. We conclude that the novel smooth contact formulation presents a memory-efficient method for contact problems in voxel-based μFE models. It presents the first method that allows modeling finite slip in large-scale voxel meshes common to high-resolution image-based models of bone while keeping the benefits of a fast and efficient voxel-based solution scheme.",1,https://api.osf.io/v2/files/59ff5e9f594d900265659b9a/,452,https://engrxiv.org/a6zmp/,10.31224/osf.io/a6zmp,,2017-11-05T19:16:07.627813,2018-07-02T11:20:49.269187 | |
| x4r5z,"Data Fusion on Motion and Magnetic Sensors embedded on Mobile Devices for the Identification of Activities of Daily Living","Several types of sensors have been available in off-the-shelf mobile devices, including motion, magnetic, vision, acoustic, and location sensors. This paper focuses on the fusion of the data acquired from motion and magnetic sensors, i.e., accelerometer, gyroscope and magnetometer sensors, for the recognition of Activities of Daily Living (ADL) using pattern recognition techniques. The system developed in this study includes data acquisition, data processing, data fusion, and artificial intelligence methods. Artificial Neural Networks (ANN) are included in artificial intelligence methods, which are used in this study for the recognition of ADL. The purpose of this study is the creation of a new method using ANN for the identification of ADL, comparing three types of ANN, in order to achieve results with a reliable accuracy. The best accuracy was obtained with Deep Learning, which, after the application of the L2 regularization and normalization techniques on the sensors’ data, reports an accuracy of 89.51%.",1,https://api.osf.io/v2/files/59fb7e55594d90026bd9361f/,410,https://engrxiv.org/x4r5z/,10.31224/osf.io/x4r5z,,2017-11-02T20:30:17.055451,2018-07-02T11:20:44.112849 | |
| qywzp,"Predicting Liquefaction in Near-Real-Time (NRT): An Assessment of Geospatial vs. Geotechnical Models During the Canterbury Earthquakes","Semi-empirical models based on in-situ geotechnical tests have become the standard | |
| of practice for predicting soil liquefaction. Since the inception of the “simplified” | |
| cyclic-stress model in 1971, variants based on various in-situ tests have been | |
| developed, including the Cone Penetration Test (CPT). More recently, prediction | |
| models based soley on remotely-sensed data were developed. Similar to systems | |
| that provide automated content on earthquake impacts, these “geospatial” models | |
| aim to predict liquefaction for rapid response and loss estimation using readilyavailable | |
| data. This data includes (i) common ground-motion intensity measures | |
| (e.g., PGA), which can either be provided in near-real-time following an earthquake, | |
| or predicted for a future event; and (ii) geospatial parameters derived from digital | |
| elevation models, which are used to infer characteristics of the subsurface relevent | |
| to liquefaction. However, the predictive capabilities of geospatial and geotechnical | |
| models have not been directly compared, which could elucidate techniques for | |
| improving the geospatial models, and which would provide a baseline for measuring | |
| improvements. Accordingly, this study assesses the realtive efficacy of liquefaction | |
| models based on geospatial vs. CPT data using 9,908 case-studies from the 2010- | |
| 2016 Canterbury earthquakes. While the top-performing models are CPT-based, the | |
| geospatial models perform relatively well given their simplicity and low cost. | |
| Although further research is needed (e.g., to improve upon the performance of | |
| current models), the findings of this study suggest that geospatial models have the | |
| potential to provide valuable first-order predictions of liquefaction occurence and | |
| consequence. Towards this end, performance assessments of geospatial vs. | |
| geotechnical models are ongoing for more than 20 additional global earthquakes",1,https://api.osf.io/v2/files/59f56e1a594d90026bd6c7b6/,555,https://engrxiv.org/qywzp/,10.31224/osf.io/qywzp,,2017-10-29T06:01:38.129297,2018-07-02T11:19:43.795274 | |
| 4mp5h,"Fragility functions for performance-based ground failure due to soil liquefaction","The severity of liquefaction manifested at the ground surface is a pragmatic proxy of damage potential for various infrastructure assets, making it particularly useful for hazard mapping, land-use planning, and preliminary site-assessment. Towards this end, the recent Canterbury, New Zealand, earthquakes, in conjunction with others, have resulted in liquefaction case-history data of unprecedented quantity and quality, presenting a unique opportunity to rigorously develop fragility-functions for liquefaction-induced ground failure. Accordingly, this study analyzes nearly 10,000 liquefaction case studies from 23 global earthquakes to develop fragility functions for use in performance-based frameworks. The proposed functions express the probability of exceeding specific severities of liquefaction surface manifestation as a function of three different liquefaction damage measures (LDMs), wherein four alternative liquefaction-triggering models are used. These functions have the same functional form, such that end-users can easily select the model coefficients for the particular damage state, triggering model, and LDM of their choosing.It should be noted that these functions are not to be used to predict lateral spreading, which requires LDMs other than those assessed herein. Lastly, the proposed functions are preliminary and subject to further development. In this regard, several thrusts of ongoing investigation are discussed.",1,https://api.osf.io/v2/files/59f56d3b594d900269d6e7d9/,450,https://engrxiv.org/4mp5h/,10.31224/osf.io/4mp5h,,2017-10-29T05:58:09.869702,2018-07-02T11:19:43.753384 | |
| 5cugd,"Moving Towards an Improved Liquefaction Hazard Framework: Lessons Resulting From the 2010-2011 Canterbury, New Zealand, Earthquake Sequence","The 2010-2011 Canterbury, New Zealand,Earthquake Sequence (CES) resulted in a liquefaction dataset of unprecedented size and quality, presenting a truly unique opportunity to assess and improve the efficacy of liquefaction-analyticsin the field. Towards this end, the study presented herein develops and analyzes a database of 10,000 high-quality liquefaction case histories resulting from the CES. The objectives of these analyses are varied, but underlying each is the desire to more accurately assess liquefaction hazard for civil infrastructure (i.e., to predict both the occurrence and damage-potential of soil liquefaction). Major contributions from this work include, but are not limited to: (1) the Liquefaction Potential Index (LPI), the state-of-practice framework for assessing liquefaction hazard, is shown to produce erroneous predictions for a significant percentage of the assessed case histories; (2) the cause of poor predictions is rigorously investigated and specific shortcomings of the LPI framework are identified; (3) based on the limitations identified, and using insights from historical data, a revised liquefaction hazard framework is developed; and (4) the revised framework is shown to assess liquefaction hazard more efficiently relative to both LPI and a competing alternative framework newly proposed in the literature. Ultimately, significant room for improvement remains with respect to accurate assessment of liquefaction hazard. The findings presented in this dissertation thus form the basis for future development of a further-improved framework. Moreover, a methodology is proposed by which improvements can be measured in a standardized and objective manner.",1,https://api.osf.io/v2/files/59f56bd66c613b026b5006f5/,369,https://engrxiv.org/5cugd/,10.31224/osf.io/5cugd,,2017-10-29T05:51:58.302320,2018-07-02T11:19:43.711733 | |
| kdhb7,"Framework for Incorporating Downscaled Climate Output into Existing Engineering Methods: Application to Precipitation Frequency Curves","To improve the resiliency of designs, particularly for long-lived infrastructure, current engineering practice must be updated to incorporate a range of future climate conditions that are likely to be different from the past. However, a considerable mismatch exists between climate model outputs and the data inputs needed for engineering designs. The present work provides a framework for incorporating climate trends into design standards and applications, including: selecting the appropriate climate model source based on the intended application, understanding model performance and uncertainties, addressing differences in temporal and spatial scales, and interpreting results for engineering design. The framework is illustrated through an application to depth-duration-frequency curves, which are commonly used in stormwater design. A change factor method is used to update the curves in a case study of Pittsburgh, PA. Extreme precipitation depth is expected to increase in the future for Pittsburgh for all return periods and durations examined, requiring revised standards and designs. Doubling the return period and using historical, stationary values may enable adequate design for short duration storms; however, this method is shown to be insufficient to enable protective designs for larger duration storms.",1,https://api.osf.io/v2/files/59ed55f5b83f690263755adc/,425,https://engrxiv.org/kdhb7/,10.31224/osf.io/kdhb7,10.1061/(ASCE)IS.1943-555X.0000382,2017-10-23T02:52:11.579782,2018-07-02T11:17:46.765005 | |
| m9rnz,"Vector Quantization using the Improved Differential Evolution Algorithm for Image Compression","Vector Quantization (VQ) is a popular image compression technique with a simple decoding architecture and high compression ratio. Codebook designing is the most essential part in Vector Quantization. Linde–Buzo–Gray (LBG) is a traditional method of generation of VQ Codebook which results in lower PSNR value. A Codebook affects the quality of image compression, so the choice of an appropriate codebook is a must. Several optimization techniques have been proposed for global codebook generation to enhance the quality of image compression. In this paper, a novel algorithm called IDE-LBG is proposed which uses Improved Differential Evolution Algorithm coupled with LBG for generating optimum VQ Codebooks. The proposed IDE works better than the traditional DE with modifications in the scaling factor and the boundary control mechanism. The IDE generates better solutions by efficient exploration and exploitation of the search space. Then the best optimal solution obtained by the IDE is provided as the initial Codebook for the LBG. This approach produces an efficient Codebook with less computational time and the consequences include excellent PSNR values and superior quality reconstructed images. It is observed that the proposed IDE-LBG find better VQ Codebooks as compared to IPSO-LBG, BA-LBG and FA-LBG.",1,https://api.osf.io/v2/files/59e332069ad5a102b3884df9/,371,https://engrxiv.org/m9rnz/,10.31224/osf.io/m9rnz,,2017-10-15T10:08:43.944514,2018-07-02T11:15:52.841816 | |
| n7dgs,"Ground motion observations from the 14 November 2016 Mw7.8 Kaikoura, New Zealand earthquake and insights from broadband simulations","This paper provide insights into the observed ground motion records from the 14 November 2016 $M_w7.8$ Kaikoura earthquake. | |
| Specific detail is given to examining observations in the near-source and those in the urban Wellington / Lower Hutt regions through a combination of time series and response spectra to understand salient source, path and site effects. | |
| Several ground motions exceeding 1.0g horizontal are recorded, as well as up to 2.7g in the vertical direction at one location. | |
| The complexity associated with multi-fault rupture is clearly evident in several strong motion stations in the near-source region. | |
| Significant site effect case histories from sedimentary and reclaimed soil deposits and topographic effects are observed in the Wellington and Lower Hutt regions. | |
| To provide further insights, predictions from preliminary broadband ground motion simulations are examined to more directly interpret the observations.",1,https://api.osf.io/v2/files/59dc6bba594d9002c62bc4e4/,237,https://engrxiv.org/n7dgs/,10.31224/osf.io/n7dgs,10.1785/0220160225,2017-10-10T06:44:40.084074,2018-07-02T11:15:46.171621 | |
| 6xshk,"An Automated System To Replace A Human User In Conventional Laboratory Well Plate Imaging","We here developed an automated well plate imaging system to eliminate the requirement for continuous human operation, thus freeing up the valuable time of a scientific researcher and removing the possibility of fatigue-induced human error. Specifically, we created a prototype system with programmed two-dimensional movement, automated calibration, variable plate configuration compatibility, variable path feasibility, reliable well plate image capture, and an intuitive graphical user interface. Successful implementation of our device would immediately benefit laboratory scientists, giving them more time to pursue the next biomedical breakthroughs.",1,https://api.osf.io/v2/files/59cc07e9594d9002b87402b9/,462,https://engrxiv.org/6xshk/,10.31224/osf.io/6xshk,,2017-09-27T20:34:46.525526,2018-07-02T11:13:32.118452 | |
| 2jxy7,"Sustainable remediation of antibacterials, metals and DNA","The global antibacterial crisis requires urgent attention from environmental engineering and bioengineering. Here, unit operation efficiencies are assessed, in a novel water treatment train capable of remediating antibacterials, metals and DNA. This technological cycle relies on bioremediation, high temperature and pressure. The analyses used 14C-respirometry, spectrometry, and a set of molecular analyses. Multiresistant bacteria hold antibacterial resistance genes (ARGs); they were harnessed for bioremediation of pollutant mixtures. Treatment efficiencies were 25-71% for 8-days aerobic metal reduction and removal (CrVI: 255, Cd: 0.65, and Pb: 0.65 mg L-1 initial concentrations); 34.8% erythromycin (ERY) 20-days biodegradation (from 750 mg L-1). The anaerobic digestion (AD) bioremediated mixed antibacterials (65-73% in 60 days from initial 100 mg L-1). However, high concentrations of mixed antibacterials (SMX+ERY) induced stronger inhibition of enzymatic activity, higher sensitivity of bacteria and acetoclastic methanogens, and higher diversity of ARGs. ARGs justified complete DNA degradation (60°C at 5.8 kPa for 10 min). The suggested coupling sequence of operations was metal then antibacterial aerobic bioremediation (as pre-treatments to anaerobic digestion), anaerobic bioremediation (also yielding biomethane as heat source), recirculation of ARGs in situ, and thermal-barometric DNA degradation.",1,https://api.osf.io/v2/files/59c99935b83f69025d6b143f/,344,https://engrxiv.org/2jxy7/,10.31224/osf.io/2jxy7,,2017-09-26T00:31:28.343994,2018-07-02T11:13:29.551424 | |
| 9wqfn,"Measuring and Predicting Sooting Tendencies of Oxygenates, Alkanes, Alkenes, Cycloalkanes, and Aromatics on a Unified Scale","Soot from internal combustion engines negatively affects health and climate. Soot emissions might be reduced through the expanded usage of appropriate biomass-derived fuels. Databases of sooting indices, based on measuring some aspect of sooting behavior in a standardized combustion environment, are useful in providing information on the comparative sooting tendencies of different fuels or pure compounds. However, newer biofuels have varied chemical structures including both aromatic and oxygenated functional groups, making an accurate measurement or prediction of their sooting tendency difficult. In this work, we propose a unified sooting tendency database for pure compounds, including both regular and oxygenated hydrocarbons, which is based on combining two disparate databases of yield-based sooting tendency measurements in the literature. Unification of the different databases was made possible by leveraging the greater dynamic range of the color ratio pyrometry soot diagnostic. This unified database contains a substantial number of pure compounds (≥ 400 total) from multiple categories of hydrocarbons important in modern fuels and establishes the sooting tendencies of aromatic and oxygenated hydrocarbons on the same numeric scale for the first time. Using this unified sooting tendency database, we have developed a predictive model for sooting behavior applicable to a broad range of hydrocarbons and oxygenated hydrocarbons. The model decomposes each compound into single-carbon fragments and assigns a sooting tendency contribution to each fragment based on regression against the unified database. The model’s predictive accuracy (as demonstrated by leave-one-out cross-validation) is comparable to a previously developed, more detailed predictive model. The fitted model provides insight into the effects of chemical structure on soot formation, and cases where its predictions fail reveal the presence of more complicated kinetic sooting mechanisms. This work will therefore enable the rational design of low-sooting fuel blends from a wide range of feedstocks and chemical functionalities.",1,https://api.osf.io/v2/files/59bac74f594d9002514e31a4/,923,https://engrxiv.org/9wqfn/,10.31224/osf.io/9wqfn,10.1016/j.combustflame.2017.12.005,2017-09-14T18:23:26.438347,2019-03-04T20:27:19.773207 | |
| wfcds,"FRUIT AND VEGETABLE WASH-WATER CHARACTERIZATION, TREATMENT FEASIBILITY STUDY AND DECISION MATRICES","On average, it is estimated that up to 5 liters of wastewater is generated per kg of produce in post-harvest processing of fruit, leafy greens and root vegetables. The typical wastewater parameters vary in concentration (solids content, COD, BOD, nitrogen, phosphorus) based on the produce being processed. The challenge for producers and regulators is that the selection of the appropriate treatment technology is challenging, so decision matrices were developed to narrow down the treatment selections. Wash-waters for different types of fruit and vegetables from two different operation types, washing only vs. washing and processing. Bench-scale treatments selected for testing included settling, coagulation and flocculation with settling, centrifuge, dissolved air flotation, electrocoagulation, screening, and hydrocyclone. The developed decision matrices summarize the removal effectiveness of the different treatments for typical wastewater parameters and serve as a reference tool in understanding wash-water treatment technologies and their effectiveness in treating various wash-waters.",1,https://api.osf.io/v2/files/59b2d226b83f690252eba7e7/,592,https://engrxiv.org/wfcds/,10.31224/osf.io/wfcds,10.1139/cjce-2017-0214,2017-09-08T17:29:08.537230,2018-07-02T11:10:52.026401 | |
| sa8k3,"Large Scale Bioventing Degradation Rates of Petroleum Hydrocarbons and Determination of Scale-up Factors","Bioventing is a cutting edge, non-destructive treatment method that uses indigenous soil microorganisms in-situ to remediate petroleum hydrocarbons in the unsaturated soil zone. Transferring the application of this technology to a field environment still has some uncertainties due to scale-up challenges. In order to identify the scale-up factor, a 80 kg soil reactor system was developed, consisting of a custom made reactor, climate chamber, low flow venting system and an off gas capture device. Sandy and clayey soils were tested with known concentrations of spiked synthetic gasoline. Various environmental conditions were monitored which included: moisture levels, pH, microbial levels, nutrient and oxygen levels. Results show a second stage degradation rate similar to the degradation rate obtained from research conducted with a 4 kg reactor, giving an average scale-up factor of 2.3±0.4. The completed research shows that working with a 80 kg laboratory reactor is feasible, yet not always necessary for the development of scale-up factors. A complimentary study with aged soil contaminants was preformed and yielded degradation rates that were significantly reduced.",1,https://api.osf.io/v2/files/59b2ac6c6c613b025dca7e4a/,584,https://engrxiv.org/sa8k3/,10.31224/osf.io/sa8k3,10.1080/10889868.2017.1312265,2017-09-08T14:54:28.031346,2018-07-02T11:10:51.967570 | |
| yd4pc,"New considerations about light pollution in rural and protected areas based on a global perspective savings-pollution-safety: Impact on real installations","The broad implementation of LED light sources in public lighting has become a | |
| revolution in the last years. Their low power consumption and good performance make | |
| LED an optimal solution in most of outdoor applications. In addition, the white light | |
| emitted by the vast majority of the LED used in public lighting and their good color | |
| rendering allow pedestrians and drivers enjoy of more comfortable cities at night, | |
| especially commercial zones and city centre. However, the regulations on light | |
| pollution, that in some countries have been developed in parallel to the introduction of | |
| LED lighting, present strong constrains to white light due to Rayleigh scattering. These | |
| regulations request filtering of blue wavelengths in some rural areas, and thus they limit | |
| the projects to high pressure sodium sources or amber LEDs, whose prices are higher | |
| and performances lower than for white LEDs. In this work, the pros and contras of | |
| white and amber LED lighting in rural areas are analyzed and compared through real | |
| simulations and considerations based on efficiency and light pollution. Important | |
| conclusions for installations in rural and protected areas are presented.",1,https://api.osf.io/v2/files/59afe27db83f69025383f190/,617,https://engrxiv.org/yd4pc/,10.31224/osf.io/yd4pc,,2017-09-06T12:03:58.091134,2018-07-02T11:10:49.450679 | |
| pgtuq,"Mechatronics Workshop for Elementary School Outreach","In an attempt to engage a classroom of fifth-grade students in an engineering design experience, we took advantage of the prior experiences of a larger collaboration which demonstrated that these students gravitate towards projects which involve electronics while also providing an opportunity to help people. The field of assistive technology, which provides a means of achieving greater independence and standard of living through the integration of technology with the tasks of everyday life and work, served as a suitable application for the student's natural inclinations towards helping others. Supporting evidence was also found in the literature where it is argued that assistive technology is a field that provides a rich opportunity for students to engage with their peers, their community, and the world at large in a meaningful way. Further, the use of project-based design experiences has been shown to improve student engagement, use of divergent thinking, and teamwork skills. | |
| This paper reports on the outcomes of this workshop, constructed to introduce the students to the design process from an engineering context, mechatronics, and assistive technology. The workshop focused on design of a mechatronic device using an Arduino inventor kit. The workshop introduced fundamentals of connecting the Arduino to a laptop, wiring simple circuits, and coding in the C++ programming language. Students were also briefed on the background of the field of assistive technology and were presented with a design challenge which would require them to design and prototype an assistive technology device to improve the daily life for a particular client.",1,https://api.osf.io/v2/files/59a9a95bb83f69025bb3b476/,572,https://engrxiv.org/pgtuq/,10.31224/osf.io/pgtuq,,2017-09-01T18:44:00.695453,2018-07-02T11:09:34.989454 | |
| c9eka,"Automatic localization of Deep Stimulation Electrodes using trajectory-based segmentation approach","Parkinson's disease (PD) is a degenerative condition of the | |
| nervous system, which manifests itself primarily as muscle sti ness, hypokinesia, | |
| bradykinesia, and tremor. In patients su ering from advanced | |
| stages of PD, Deep Brain Stimulation neurosurgery (DBS) is the best | |
| alternative to medical treatment, especially when they become tolerant | |
| to the drugs. This surgery produces a neuronal activity, a result of electrical | |
| stimulation, whose quanti cation is known as Volume of Tissue | |
| Activated (VTA). To locate the VTA correctly in the cerebral volume | |
| space, one should be aware of exactly the location on the tip of the DBS | |
| electrodes, as well as their spatial projection. | |
| In this paper, we automatically locate DBS electrodes using a thresholdbased | |
| medical imaging segmentation methodology, determining the optimal | |
| value of this threshold adaptively. The proposed method allows the | |
| localization of DBS electrodes in Computed Tomography (CT) images, | |
| with high noise tolerance, using automatic threshold detection methods.",1,https://api.osf.io/v2/files/59a43325594d900044792741/,490,https://engrxiv.org/c9eka/,10.31224/osf.io/c9eka,,2017-08-28T15:16:12.686051,2018-07-02T11:09:28.248004 | |
| 5kqzd,"A Type–II Fuzzy Entropy Based Multi-Level Image Thresholding Using Adaptive Plant Propagation Algorithm","One of the most straightforward, direct and efficient approaches to Image Segmentation is | |
| Image Thresholding. Multi-level Image Thresholding is an essential viewpoint in many image processing and | |
| Pattern Recognition based real-time applications which can effectively and efficiently classify the pixels into | |
| various groups denoting multiple regions in an Image. Thresholding based Image Segmentation using fuzzy | |
| entropy combined with intelligent optimization approaches are commonly used direct methods to properly | |
| identify the thresholds so that they can be used to segment an Image accurately. In this paper a novel approach | |
| for multi-level image thresholding is proposed using Type II Fuzzy sets combined with Adaptive Plant | |
| Propagation Algorithm (APPA). Obtaining the optimal thresholds for an image by maximizing the entropy is | |
| extremely tedious and time consuming with increase in the number of thresholds. Hence, Adaptive Plant | |
| Propagation Algorithm (APPA), a memetic algorithm based on plant intelligence, is used for fast and efficient | |
| selection of optimal thresholds. This fact is reasonably justified by comparing the accuracy of the outcomes and | |
| computational time consumed by other modern state-of-the-art algorithms such as Particle Swarm | |
| Optimization (PSO), Gravitational Search Algorithm (GSA) and Genetic Algorithm (GA).",1,https://api.osf.io/v2/files/599c926fb83f690252666b63/,405,https://engrxiv.org/5kqzd/,10.31224/osf.io/5kqzd,,2017-08-22T20:26:08.518005,2018-07-02T11:08:04.284572 | |
| sh8p4,"Adaptive Plant Propagation Algorithm for Solving Economic Load Dispatch Problem","Optimization problems in design engineering are complex by nature, often because of the involvement of critical objective functions accompanied by a number of rigid constraints associated with the products involved. One such problem is Economic Load Dispatch (ED) problem which focuses on the optimization of the fuel cost while satisfying some system constraints. Classical optimization algorithms are not sufficient and also inefficient for the ED problem involving highly nonlinear, and non-convex functions both in the objective and in the constraints. This led to the development of metaheuristic optimization approaches which can solve the ED problem almost efficiently. This paper presents a novel robust plant intelligence based Adaptive Plant Propagation Algorithm (APPA) which is used to solve the classical ED problem. The application of the proposed method to the 3-generator and 6-generator systems shows the efficiency and robustness of the proposed algorithm. A comparative study with another state-of-the-art algorithm (APSO) demonstrates the quality of the solution achieved by the proposed method along with the convergence characteristics of the proposed approach.",1,https://api.osf.io/v2/files/598d480b594d900045a9ac29/,607,https://engrxiv.org/sh8p4/,10.31224/osf.io/sh8p4,,2017-08-11T06:06:59.550452,2018-07-02T11:06:46.165642 | |
| 2saum,"Field-testing liquefaction models based on geospatial vs. geotechnical data","This study assesses the relative efficacy of liquefaction models based on geospatial vs. geotechnical data. In particular, state-of-practice geotechnical models based on the Cone Penetration Test (CPT) are compared to geospatial models that use readily available no-cost data. This assessment is performed using a database of 9,623 liquefaction case studies compiled from the 2010-2016 Canterbury, New Zealand, Earthquakes. While the top-performing model is CPT-based, the geospatial models perform surprisingly well given their simplicity. In particular, a region-specific geospatial model out-performs some CPT-based methods. While further research is needed, the presented findings are provocative considering the relative cost and complexity of the geotechnical models. Accordingly, performance assessments of geospatial vs. geotechnical models are ongoing for more than 20 additional earthquakes.",1,https://api.osf.io/v2/files/5989e1a0b83f69023ce35ede/,658,https://engrxiv.org/2saum/,10.31224/osf.io/2saum,,2017-08-08T16:07:40.100019,2018-07-02T11:05:28.770202 | |
| j2rs6,"Probabilistic Prediction of Severity of Liquefaction Surface Manifestation Using Geotechnical and Geospatial Models","The severity of liquefaction manifested at the ground surface is a pragmatic proxy of damage potential for various infrastructure assets, making it particularly useful for hazard mapping, land-use planning, and preliminary site-assessment. Towards this end, the recent Canterbury, New Zealand, earthquakes, in conjunction with others, have resulted in liquefaction case-history data of unprecedented quantity and quality, presenting a unique opportunity to develop fragility-functions for liquefaction-induced ground failure. Accordingly, this study analyzes nearly 10,000 liquefaction case studies from 23 earthquakes to develop functions that express the probability of exceeding specific severities of liquefaction surface-manifestation as a function of five different liquefaction damage measures (LDMs), of which three are based on geotechnical data and two are based on freely available geospatial data. The proposed functions have the same functional form, such that end-users can easily select the model coefficients for the particular damage state and LDM of their choosing. It should be noted that these functions are not to be used to predict lateral spreading, which requires LDMs other than those assessed herein. Lastly, the proposed functions are preliminary and subject to further development. In this regard, several thrusts of ongoing investigation are mentioned.",1,https://api.osf.io/v2/files/5988c7db594d900229f1bb39/,573,https://engrxiv.org/j2rs6/,10.31224/osf.io/j2rs6,,2017-08-07T20:23:29.753688,2018-07-02T11:05:28.283357 | |
| tyhqm,"REDUCING STRUCTURAL ERROR IN FUNCTION GENERATING MECHANISMS VIA THE ADDITION OF LARGE NUMBERS OF FOUR-BAR MECHANISMS","This paper presents a methodology for synthesizing planar | |
| linkages to approximate any prescribed periodic function. The | |
| mechanisms selected for this task are the slider-crank and the | |
| geared five-bar with connecting rod and sliding output (GFBS), | |
| where any number of drag-link (or double crank) four-bars are | |
| used as drivers. A slider-crank mechanism, when comparing the | |
| input crank rotation to the output slider displacement, produces | |
| a sinusoid-like function. Instead of directly driving the input | |
| crank, a drag-link four-bar may be added that drives the crank | |
| from its output via a rigid connection between the two. Driving | |
| the input of the added four-bar results in a function that is less | |
| sinusoid-like. This process can be continued through the addition | |
| of more drag-link mechanisms to the device, slowly altering | |
| the curve toward any periodic function with a single maximum. | |
| For periodic functions with multiple maxima, a GFBS is used | |
| as the terminal linkage added to the chain of drag-link mechanisms. | |
| The synthesis process starts by analyzing one period of | |
| the function to design either the terminal slider-crank or terminal | |
| GFBS. A randomized local search is then conducted as the | |
| four-bars are added to minimize the structural error between the | |
| desired function and the input-output function of the mechanism. | |
| Mechanisms have been “grown” in this fashion to dozens of links | |
| that are capable of closely producing functions with a variety of | |
| intriguing features.",1,https://api.osf.io/v2/files/598379fc6c613b022880b8b0/,683,https://engrxiv.org/tyhqm/,10.31224/osf.io/tyhqm,,2017-08-03T19:33:38.384330,2018-07-02T11:05:26.913137 | |
| dwuyr,"The Synthesis of Function Generating Mechanisms for Periodic Curves Using Large Numbers of Double-Crank Linkages","This paper presents a methodology for synthesizing planar linkages to approximate any | |
| prescribed periodic function. The mechanisms selected for this task are the slider-crank | |
| and the geared five-bar with connecting rod and sliding output (GFBS), where any number | |
| of double-crank (or drag-link) four-bars are used as drivers. A slider-crank mechanism, | |
| when comparing the input crank rotation to the output slider displacement, | |
| produces a sinusoid-like function. Instead of directly driving the input crank, a drag-link | |
| four-bar may be added to drive the crank from its output via a rigid connection between | |
| the two. Driving the input of the added four-bar results in a function that modifies the | |
| sinusoid-like curve. This process can be continued through the addition of more | |
| drag-link mechanisms to the device, progressively altering the curve toward any periodic | |
| function with a single maximum. For periodic functions with multiple maxima, a GFBS is | |
| used as the terminal linkage added to the chain of drag-link mechanisms. The synthesis | |
| process starts by analyzing one period of the function to design either the terminal slidercrank | |
| or terminal GFBS. MATLAB’s fmincon command is then utilized as the four-bars are | |
| added to reduce the structural error between the desired function and the input–output | |
| function of the mechanism. Mechanisms have been synthesized in this fashion to include | |
| a large number of links that are capable of closely producing functions with a variety of | |
| intriguing features",1,https://api.osf.io/v2/files/5983786ab83f69022cca5071/,762,https://engrxiv.org/dwuyr/,10.31224/osf.io/dwuyr,10.1115/1.4035985,2017-08-03T19:26:44.496192,2018-07-02T11:05:26.842847 | |
| n7ajq,"Hydraulic Valve for Miniature Surgical Robot Applications","This paper describes the design and testing of a novel hydraulic control valve for use in the minimally invasive surgical robotic manipulator. The use of hydraulics for surgical robotics opens new possibilities for miniaturization and robustness. However, to enable this, there exists a need for hydraulic components which bridge the size gap between traditional fluidics and microfluidics. This paper provides motivation for the development of a miniature hydraulic valve designed specifically to enable a serpentine style hydraulic surgical manipulator. Included are a description of the various considerations relevant to the valve and its specific application, such as the method of manipulation for the valve, as well as a theoretical valve design and a mathematical description of the operating principles. Two possible methods of valve activation, piezoelectric and electromagnetic, are discussed along with two physical realizations of the valve design are presented which demonstrate the theoretical design. Finally, the results of experimental testing performed on valve prototypes is described to evaluate the design options and help inform the selection of the final configuration. | |
| This is a preprint of an article submitted for consideration in ADVANCED ROBOTICS, copyright Taylor & Francis and Robotics Society of Japan; ADVANCED ROBOTICS is available online at http://www.tandfonline.com/tadr.",1,https://api.osf.io/v2/files/597e8bcc6c613b023a8d3b91/,788,https://engrxiv.org/n7ajq/,10.31224/osf.io/n7ajq,,2017-07-31T01:56:04.812476,2018-07-02T11:05:24.640652 | |
| ekus8,"Blast actions from high explosives. Studies on their simulation and effects","Bombing attacks are one of the most destructive means of the terrorist threat in terms of both human lifes and cultural heritage. The mechanical problem of the effects of a blast on structures, in order to assess their vulnerability and design functioning protections for saving human lifes and preserving historical monuments, is a crucial issue for the present international situation. Here, we introduce a strategy suited for the calculation of the blast actions on structures comparing three different numerical schemes: JWL, CONWEP and TM5-1300. A procedure based upon precise interpolations of the experimental data allows comparison of the above models on simple cases. | |
| We simulate first a blast inside Pantheon in Rome, taking into account for the complex pattern of multiple reflected blast waves and the nonlinearities of no-tension materials. Then, we consider the response to an explosion inside a fuselage made of aluminium alloys. In this last case we discuss the opportunity given by cost-effective numerical approaches in designing protections through the development of a new concept of a passive protective | |
| device for aircrafts cabins.",1,https://api.osf.io/v2/files/597c1bd1594d90024439385e/,914,https://engrxiv.org/ekus8/,10.31224/osf.io/ekus8,,2017-07-29T05:26:53.495711,2018-07-02T11:05:24.375270 | |
| 5ua7g,"The Internet of Hackable Things","The Internet of Things makes possible to connect each everyday object to the Internet, making computing pervasive like never before. From a security and privacy perspective, this tsunami of connectivity represents a disaster, which makes each object remotely hackable. We claim that, in order to tackle this issue, we need to address a new | |
| challenge in security: education.",1,https://api.osf.io/v2/files/59773c32b83f69022a31a022/,647,https://engrxiv.org/5ua7g/,10.31224/osf.io/5ua7g,,2017-07-25T12:46:30.853727,2018-07-02T11:05:22.349036 | |
| umkz8,"Chest Wall Kinematics Using Triangular Cosserat Point Elements in Healthy and Neuromuscular Subjects","Optoelectronic plethysmography (OEP) is a noninvasive method for assessing lung volume variations and the contributions of different anatomical compartments of the chest wall (CW) through measurements of the motion of markers attached to the CW surface. The present study proposes a new method for analyzing the local CW kinematics from OEP measurements based on the kinematics of triangular Cosserat point elements (TCPEs). 52 reflective markers were placed on the anterior CW to create a mesh of 78 triangles according to an anatomical model. Each triangle was characterized by a TCPE and its kinematics was described using four time-variant scalar TCPE parameters. The total CW volume ( VTCW) and the contributions of its six compartments were also estimated, using the same markers. The method was evaluated using measurements of ten healthy subjects, nine patients with Pompe disease, and ten patients with Duchenne muscular dystrophy (DMD), during spontaneous breathing (SB) and vital capacity maneuvers (VC) in the supine position. TCPE parameters and compartmental volumes were compared with VTCW by computing the phase angles θ (for SB) and the correlation r (for VC) between them. Analysis of θ and r of the outward translation parameter PT of each TCPE revealed that for healthy subjects it provided similar results to those obtained by compartmental volumes, whereas for the neuromuscular patients the TCPE method was capable of detecting local asynchronous and paradoxical movements also in cases where they were undistinguished by volumes. Therefore, the TCPE approach provides additional information to OEP that may enhance its clinical evaluation capabilities.",1,https://api.osf.io/v2/files/59725772b83f69022a2ffa1f/,542,https://engrxiv.org/umkz8/,10.31224/osf.io/umkz8,10.1007/s10439-017-1840-6,2017-07-21T19:41:31.566704,2018-07-02T11:03:33.382973 | |
| yfqxr,"Bone Orientation and Position Estimation Errors Using Cosserat Point Elements and Least Squares methods: Application to Gait","The aim of this study was to analyze the accuracy of bone pose estimation based on sub-clusters of three skin-markers characterized by triangular Cosserat point elements (TCPEs) and to evaluate the capability of four instantaneous physical parameters, which can be measured non-invasively in-vivo, to identify the most accurate TCPEs. Moreover, TCPE pose estimations were compared with the estimations of two least squares minimization methods applied to the cluster of all markers, using rigid body (RBLS) and homogeneous deformation (HDLS) assumptions. Analysis was performed on previously collected in-vivo treadmill gait data composed of simultaneous measurements of the gold-standard bone pose by bi-plane fluoroscopy tracking the subjects' knee prosthesis and a stereophotogrammetric system tracking skin-markers affected by soft tissue artifact. Femur orientation and position errors estimated from skin-marker clusters were computed for 18 subjects using clusters of up to 35 markers. Results based on gold-standard data revealed that instantaneous subsets of TCPEs exist which estimate the femur pose with reasonable accuracy (median root mean square error during stance/swing: 1.4/2.8 deg for orientation, 1.5/4.2 mm for position). A non-invasive and instantaneous criteria to select accurate TCPEs for pose estimation (4.8/7.3 deg, 5.8/12.3 mm), was compared with RBLS (4.3/6.6 deg, 6.9/16.6 mm) and HDLS (4.6/7.6 deg, 6.7/12.5 mm). Accounting for homogeneous deformation, using HDLS or selected TCPEs, yielded more accurate position estimations than RBLS method, which, conversely, yielded more accurate orientation estimations. Further investigation is required to devise effective criteria for cluster selection that could represent a significant improvement in bone pose estimation accuracy.",1,https://api.osf.io/v2/files/59725181594d90022b80ca76/,526,https://engrxiv.org/yfqxr/,10.31224/osf.io/yfqxr,10.1016/j.jbiomech.2017.01.026,2017-07-21T19:34:28.904807,2018-07-02T11:03:33.301639 | |
| 397zy,"Unphysical properties of the rotation tensor estimated by least squares optimization with specific application to biomechanics","Analysis of the transformation of one data set into another is a ubiquitous problem in many fields of science. Many works approximate the transformation of a reference cluster of n vectors Xi (i=1,2,..,n) into another cluster of n vectors xi by a translation and a rotation using a least squares optimization to obtain the rotation tensor Q. The objective of this work is to prove that this rotation tensor Q exhibits unphysical dependence on the shape and orientation of the reference cluster. In contrast, when the transformation is approximated by a translation and a general non-singular tensor F, which includes deformations, then the associated rotation tensor R does not exhibit these unphysical properties. An example in biomechanics quantifies the errors of these unphysical properties.",1,https://api.osf.io/v2/files/59724f296c613b022a36f5eb/,554,https://engrxiv.org/397zy/,10.31224/osf.io/397zy,10.1016/j.ijengsci.2016.02.001,2017-07-21T19:02:42.591003,2018-07-02T11:03:33.240155 | |
| b3az4,"Bone Pose Estimation in the Presence of Soft Tissue Artifact Using Triangular Cosserat Point Elements","Accurate estimation of the position and orientation (pose) of a bone from a cluster of skin markers is limited mostly by the relative motion between the bone and the markers, which is known as the Soft Tissue Artifact (STA). This work presents a method, based on continuum mechanics, to describe the kinematics of a cluster affected by STA. The cluster is characterized by Triangular Cosserat Point Elements (TCPEs) defined by all combinations of three markers. The effects of the STA on the TCPEs are quantified using three parameters describing the strain in each TCPE and the relative rotation and translation between TCPEs. The method was evaluated using previously collected ex-vivo kinematic data. Femur pose was estimated from 12 skin markers on the thigh, while its reference pose was measured using bone pins. Analysis revealed that instantaneous subsets of TCPEs exist which estimate bone position and orientation more accurately than the Procrustes Superimposition applied to the cluster of all markers. It has been shown that some of these parameters correlate well with femur pose errors, which suggests that they can be used to select, at each instant, subsets of TCPEs leading an improved estimation of the underlying bone pose.",1,https://api.osf.io/v2/files/59724dc3594d90022880d2ed/,595,https://engrxiv.org/b3az4/,10.31224/osf.io/b3az4,10.1007/s10439-015-1384-6,2017-07-21T18:58:57.529110,2018-07-02T11:03:33.183848 | |
| spge4,"Soft Tissue Artifact Compensation Using Triangular Cosserat Point Elements (TCPEs)","Existing methods which compensate for the Soft Tissue Artifact (STA) in optoelectronic motion measurements estimate the rigid motion of a nearly rigid underlying body segment based on analysis of the motion of all fiducial markers. The objective of the proposed Triangular Cosserat Point Elements (TCPE) method is to estimate the motion of the underlying body segment even when the STA in the entire cluster of markers can be large. This is accomplished by characterizing the cluster of markers with TCPEs defined by triangles based on all combinations of three markers. Then, scalar deformation measures characterizing the magnitudes of strain and relative rotation of pairs of TCPEs are defined for each TCPE. These deformation measures are used to define a filtered group of TCPEs which best represents the motion of the underlying body segment. The method was tested using an experimental setup that consists of a rigid pendulum with a deformable 300ml silicone breast implant attached to it as a simulation of the soft tissue around a bony segment. The rotation angles extracted from markers on the deformable implant were compared with simultaneous measurements of the rigid pendulum using an optoelectronic system. Analysis of the experimental data shows that this filtering process substantially reduces the error due to the STA even though the data set includes large deformations. In particular, the analysis shows that the error reduction using the TCPE approach is larger than the reductions obtained using standard least-squares minimization methods.",1,https://api.osf.io/v2/files/59724bba594d90022880d214/,589,https://engrxiv.org/spge4/,10.31224/osf.io/spge4,10.1016/j.ijengsci.2014.07.001,2017-07-21T18:50:24.561189,2018-07-02T11:03:33.135747 | |
| ufjkr,"A Sustainable Design Repository for Influencing the Eco-Design of New Consumer Products","Engineering designers are constantly seeking ways to be more innovative, decisive, and informed of emerging technologies in the design of consumer products. Design tools, such as functional decomposition, morphology, and Pugh charts help stimulate the design process. However, many early-design-phase design tools require designers to have experiential or empirical design knowledge; many of these approaches are intractable for use by novice designers or designers with little experience designing for certain new objectives. In contrast to these current tools, using repositories to store product design information can provide additional and extensive design knowledge to the global design community. Using repository data—and resultant data-driven design approaches—in the design of new products can be especially impactful for DfX design objectives such as product sustainability, about which many engineering designers have limited knowledge. In this paper, we discuss the creation of a sustainable design repository – a collection of product data that includes environmental impact information. Through the initialization of a 47-product repository case study, we seek to create data-driven design processes that can influence designers to consider environmental sustainability. We found, for example, that in the first year of a product’s life, 29-64% of the environmental impact occurs during the product’s use phase, and that uncertainty in input data (such as component manufacturing location and disposal method) can significantly contribute to environmental impact variation. The creation of this sustainable design repository highlights the need for the consideration of input uncertainties when conducting environmental impact analysis. Additionally, the repository has also been used in tandem with machine learning to understand design decisions that lead to more sustainable products. This sustainable design repository enables subsequent data-driven design research in that it provides a large dataset on which machine learning approaches can operate.",1,https://api.osf.io/v2/files/596fcd7ab83f69022b103d3e/,617,https://engrxiv.org/ufjkr/,10.31224/osf.io/ufjkr,,2017-07-19T21:28:05.687921,2018-07-02T11:03:31.826979 | |
| wtxfc,"A Novel MRI Compatible Soft Tissue Indentor and Fibre Bragg Grating Force Sensor","MRI is an ideal method for non-invasive soft tissue mechanical properties investigation. This requires mechanical excitation of the body’s tissues and measurement of the corresponding boundary conditions such as soft tissue deformation inside the MRI environment. However, this is technically difficult since load application and measurement of boundary conditions requires MRI compatible actuators and sensors. This paper describes a novel MRI compatible computer controlled soft tissue indentor and optical Fibre Brag Grating (FBG) force sensor.",1,https://api.osf.io/v2/files/596cb97e9ad5a1022b407fa0/,629,https://engrxiv.org/wtxfc/,10.31224/osf.io/wtxfc,10.1016/j.medengphy.2012.06.014,2017-07-17T13:30:50.516728,2018-07-02T11:03:31.046775 | |
| vh8ka,"AntibIoTic: Protecting IoT Devices Against DDoS Attacks","The 2016 is remembered as the year that showed to the world how dangerous distributed Denial of Service attacks can be. Gauge of the disruptiveness of DDoS attacks is the number of bots involved: the bigger the botnet, the more powerful the attack. This character, along with the increasing availability of connected and insecure IoT devices, makes DDoS and IoT the perfect pair for the malware industry. In this paper we present the main idea behind AntibIoTic, a palliative solution to prevent DoS attacks perpetrated through IoT devices.",1,https://api.osf.io/v2/files/596c850d9ad5a1022a406787/,987,https://engrxiv.org/vh8ka/,10.31224/osf.io/vh8ka,,2017-07-17T09:50:00.617658,2018-07-02T11:03:30.993508 | |
| d74ec,"Is it time to adjust the sails? On the philosophy of structural reliability","The paper studies some gestalt switches in structural reliability. Then it makes a point for looking at the problem from a structuralist view. It further shows that subset simulation is a wrong approach for failure probability computation. A new method for it, called onion concept, is proposed.",1,https://api.osf.io/v2/files/5960629a9ad5a1023edf1c88/,578,https://engrxiv.org/d74ec/,10.31224/osf.io/d74ec,,2017-07-08T04:48:22.522838,2018-07-02T11:03:27.168777 | |
| jzac9,"The Holos Reactor: A Distributable Power Generator with Transportable Subcritical Power Modules","Holos is a distributable modular nuclear power generator with enhanced safety features. Holos design objectives include production of affordable pollutant-free electricity and process heat with the safest melt-tolerant and proliferation resistant fuels. The design leverages commercial tech- nologies utilized for the conversion of thermal energy into conditioned electricity. Holos can op- erate as a stand-alone electric island at sites with no power grid infrastructure and can be scaled- up or clustered to meet local electric demands. Specialized configurations of Holos generators can be airlifted and timely deployed to supply emergency electricity and process heat to disaster areas and to inaccessible remote locations. The proposed distributable electric generator is com- prised within dimensions and weight requirements compatible with International Standard Or- ganization (ISO) transport containers, and is formed by subcritical power modules protected from shock stressors during transport. Holos coupled core becomes critical and enables power generation only when multiple subcritical power modules are positioned near one another. Cool- ing of Holos fuel relies only on environmental air during operations with passive decay-heat re- moval. Depending on configurations, Holos fuel cycle is 12-20 years, with 8%-15% enriched nuclear fuel sealed at all times and contained within replaceable fuel cartridges. At the end of the fuel cycle, the fuel cartridges fit within licensed transport and storage canisters for long term storage with low decommissioning cost. Holos power conversion components can be recondi- tioned when the fuel cartridges are replaced at the end of their fuel cycles and the generator can be re-licensed to resume operation for a total generator life-span of 60 years. In this design, the thermodynamic cycle utilized to convert the core thermal energy into electricity is based on the Brayton power cycle. In some configurations, the design integrates and couples a bottoming Rankine power cycle operating with organic fluids to enhance efficiency, convert decay thermal energy into electricity and support process heat applications. Holos waste heat recovery and con- version feature also relaxes thermal loading requirements at underground spent fuel repositories. The power conversion components utilized in this design are off-the-shelf, with power ratings comparable to those forming aviation jet engines and gas turbines commercially available worldwide. This approach simplifies the design and enables factory certification following the regulatory and quality assurance programs applied by the aviation industry. Holos innovative architecture provides the means to support a distributable power source satisfying various appli- cations’ requirements with enhanced safety and substantial cost reductions, thus making Holos generators competitive, and synergetic with technology sourced on renewable energy.",1,https://api.osf.io/v2/files/594fa682594d9002288af1c3/,1869,https://engrxiv.org/jzac9/,10.31224/osf.io/jzac9,,2017-06-25T12:50:30.275408,2018-07-02T11:01:26.397511 | |
| h6mdn,"DEVELOPMENT OF A NEW CO2-BASED DEMAND-CONTROLLED VENTILATION STRATEGY USING ENERGYPLUS","A significant amount of energy is being used by ventilation and air conditioning systems to maintain the indoor environmental condition in a satisfactory and comfortable level. Many buildings, either new or existing (throughout their renovation process) are subjected to energy efficiency requirements but these must not be in the expenses of indoor environmental conditions. For instance, indoor air quality (IAQ) has to be considered while improving energy efficiency, otherwise occupants might be exposed to inappropriate indoor environment. | |
| Demand-controlled ventilation (DCV) is a method that provides comfortable IAQ level with lowest energy use. In this paper, the main objective is developing a new CO2-based DCV strategy and simulating it using EnergyPlus. The IAQ and energy consumption associated to this strategy have been compared with the results of CO2-based DCV strategies previously developed by the same authors in another article. The comparison shows that the new strategy performs better, both in energy use and IAQ. The recorded energy savings ranged between 6-14% comparing with the previously developed strategies while IAQ slightly improved.",1,https://api.osf.io/v2/files/59495052b83f690228185c8b/,604,https://engrxiv.org/h6mdn/,10.31224/osf.io/h6mdn,,2017-06-20T16:49:04.080698,2018-07-02T11:01:23.730082 | |
| jq6ca,"Microservices: a Language-based Approach","Microservices is an emerging development paradigm where software is | |
| obtained by composing autonomous entities, called (micro)services. However, microservice systems are currently developed using general-purpose programming | |
| languages that do not provide dedicated abstractions for service composition. Instead, current practice is focused on the deployment aspects of microservices, in particular by using containerization. In this chapter, we make the case for a language-based approach to the engineering of microservice architectures, which we believe is complementary to current practice. We discuss the approach in general, and then we instantiate it in terms of the Jolie programming language.",1,https://api.osf.io/v2/files/5947dbc9594d900228e13e8c/,782,https://engrxiv.org/jq6ca/,10.31224/osf.io/jq6ca,,2017-06-19T14:27:45.314939,2018-07-02T11:01:22.986487 | |
| 6ut5a,"Low-Profile Self-Sealing Sample Transfer Flexure Box","A flexural bearing mechanism has enabled the development of a self-sealing box for protecting air sensitive samples during transfer between glove boxes, micro-machining equipment, and microscopy equipment. The simplicity and self-actuating feature of this design makes it applicable to many devices that operate under vacuum conditions. The models used to design the flexural mechanism are presented in detail. The device has been tested in a Zeiss Merlin GEMINI II scanning electron microscope with Li3PS4 particles, showing effective isolation from air and corrosion prevention.",1,https://api.osf.io/v2/files/592de20b594d9000441c0868/,783,https://engrxiv.org/6ut5a/,10.31224/osf.io/6ut5a,,2017-05-30T21:25:13.826873,2018-07-02T10:59:27.145544 | |
| kghqu,"Tensile shear strength and dynamic mechanical analysis of 6063 aluminium alloy and 304 stainless steel by spot welding","Mechanical properties of dissimilar metal of spot welding were tested and analyzed based on the variation in welding currents and welding times. From visual observation, the largest weld nugget recorded was 7.43 mm at 5 kA, meanwhile the smallest was 6.4 mm at 3 kA. It was found that weld nugget size increase with the increment of weld current and extension of weld time. Based on tensile result, the largest weld nugget size of 7.43 mm produced the highest tensile strength, 31.99 N/mm2 mean while the smallest weld nugget 6.4 mm produced 29.40 N/mm2. The results show that weld nugget size affect the tensile shear strength, and with the increment of weld current and extension of welding time, tensile shear strength increase. Dynamic mechanical properties defined the storage modulus, loss modulus and damping capacity of dissimilar metal spot welded. It was found that at 10 Hz frequency between 70°C to 350°C, with heating rate of 10°C/minute, the storage modulus increase with increment in weld current and the extension of weld time to 8 s. Meanwhile the loss modulus decrease with the increased of weld current and weld time. Same pattern happen to damping capacity, the value dropped with the increases of welding current and welding time.",1,https://api.osf.io/v2/files/592a3d149ad5a1004525db38/,1165,https://engrxiv.org/kghqu/,10.31224/osf.io/kghqu,,2017-05-28T03:05:42.593728,2018-07-02T10:58:12.193591 | |
| c8qrw,"The Effects of Cold Rolling Process and Annealing Treatment on Damping Properties of 3105 Aluminium Alloy","The aluminium alloy have deformed by cold rolling process to 50 percent, 60 percent, and 70 percent rolling reduction. In order to reduce the strain hardening of the samples, an annealing treatment was performed after cold worked process. The lower the rolling reduction, the higher the damping capacity of the samples. The sample for 50 percent rolling reduction before annealed has increase in damping capacity from 0.0361 to 0.1318. When the samples undergo two different annealing temperatures and soaking hours, the damping properties such as loss modulus, storage modulus, and damping capacity show some changes in trend curves and experimental value. The damping capacity for sample 50 percent rolling reduction and after annealed at temperature 300 °C for one hour was increased from 0.0193 to 0.1405 at temperature 50 °C to 380 °C. The hardness measurement showed that, the value of Vickers hardness were decrease after annealed due to the decreasing in strain hardening.",1,https://api.osf.io/v2/files/59278f7a6c613b025e6cc86c/,410,https://engrxiv.org/c8qrw/,10.31224/osf.io/c8qrw,,2017-05-26T02:17:07.896116,2018-07-02T10:58:11.369101 | |
| mqvfc,"Mechanical Properties and Microstructural Analysis of 304 Stainless Steel by TIG Welding","Gas tungsten arc welding is the process repairing and widely used in heavy engineering for joining metal. It can be uses for various type of metal and application. The aim of this project is to study the effects of 304 stainless steel with 3 mm thickness on mechanical properties and its microstructure analysis towards gas tungsten arc welding method. The variables set up in this project were current, gas flow rate and welding direction upon rolling direction of stainless steel sheet. Three current setup were used which is 60 A, 80 A and 100 A Type of filler metal used in this project was ER 308L with 1.6 diameter. Two set up for gas flow rate were used which is 8 l/m and 12 l/m. Testing that carried out were tensile test, Vickers macro hardness test with 10 kgf load and microstructure analysis by using optical microscope. The effects of microstructure in austenitic stainless steel welds is discussed. From the mechanical properties procedures, the strength of the weld metal was obtain. For hardness testing, the most important zone to be focused were heat-affected zone (HAZ) and weld metal (WM). The integrity of the welding tested by using tensile test and hardness test with different amount of current and gas flow rate.",1,https://api.osf.io/v2/files/59278d28b83f690261157e68/,459,https://engrxiv.org/mqvfc/,10.31224/osf.io/mqvfc,,2017-05-26T02:11:02.787570,2018-07-02T10:58:11.333117 | |
| qky92,"Flexural Strength and Crack Propagation of Porous Clay- Precipitated Calcium Carbonates","Porous clay-precipitated calcium carbonates were prepared via polymeric sponge replication method using precipitated calcium carbonates (PCC) and red clay as raw materials. Different compositions of precipitated calcium carbonates (PCC) which is 10 wt.% and 15 wt.% with 24 hours and 48 hours milling time were sintered at 1250°C for 2 hours respectively which influenced the flexural strength and morphology of the porous ceramic. The highest flexural strength (1.843 MPa) were obtained by 10 wt.% [CaCO3]PCC milled at 24 hours related to the lowest percentage of porosity (81.00%). Mineralogical characterization of porous ceramic were determined via X-ray diffraction (XRD) shows the presence of crystalline phases such as anorthite (2CaAl2Si2O8), gehlenite (Ca2Al2SiO7) and esseneite (CaFeAlSiO6) after sintering process. The morphological analysis via stereomicroscope shows that the porosity and struts were found due to presence of precipitated calcium carbonates that act as pore forming agent. The colour of porous ceramic between 10 wt.% [CaCO3]PCC and 15 wt.% [CaCO3]PCC shows significant difference due to iron oxide contained in the red clay which contributes to the colour of the samples. Crack propagates in the intergranular type of fracture mode due to resulted porous ceramic is a brittle material.",1,https://api.osf.io/v2/files/59278d05b83f69026415ad4a/,621,https://engrxiv.org/qky92/,10.31224/osf.io/qky92,,2017-05-26T02:10:45.053818,2018-07-02T10:58:11.298872 | |
| g58pd,"Comparative dynamic mechanical properties of non-superheated and superheated A357 alloys","The influence of superheat treatment on the microstructure and dynamic mechanical properties of A357 alloys has been investigated. The study of microstructure was performed by the optical microscope. Dynamic mechanical properties (storage modulus, loss modulus, and damping capacity) were measured by the dynamic mechanical analyzer (DMA). Microstructure showed coarser and angular eutectic Si particles with larger α-Al dendrites in the non-superheated A357 alloy. In contrast, finer and rounded eutectic Si particles together with smaller and preferred oriented α-Al dendrites have been observed in the superheated A357 alloy. Dynamic mechanical properties showed an increasing trend of loss modulus and damping capacity meanwhile a decreasing trend of storage modulus at elevated temperatures for superheated and non-superheated A357 alloys. The high damping capacity of superheated A357 has been ascribed to the grain boundary damping at elevated temperatures.",1,https://api.osf.io/v2/files/5926efb86c613b025d6c7095/,353,https://engrxiv.org/g58pd/,10.31224/osf.io/g58pd,10.4149/km_2010_3_185,2017-05-25T15:03:25.733387,2018-07-02T10:58:11.163233 | |
| xywbc,"Effect of hydrogen peroxide addition to methane fueled homogeneous charge compression ignition engines through numerical simulations","The effect of the direct injection of hydrogen peroxide into a port-injected methane fueled homogeneous charge compression ignition engine was investigated numerically. The injection of aqueous hydrogen peroxide was implemented as a means of combustion phasing control. A single cylinder homogeneous charge compression ignition engine (2.43 L Caterpillar) was modeled using the Cantera 2.0 flame code toolkit, the GRI-Mech 3.0 chemical reaction mechanism, and a single-zone slider-crank engine model. Start of injection timing and the amount of injected hydrogen peroxide were manipulated to achieve desired combustion phasing under a wide range of intake temperatures. As the concentration of hydrogen peroxide is increased, the combustion phasing is advanced up to 22 degrees for the conditions investigated in this study. This advancing effect is most pronounced at small concentrations (< 10 g H2O2 / kg CH4) and early injection timings (SOI < 25 degrees BTDC). The model suggests hydrogen peroxide can be introduced as a means of combustion phasing control while maintaining the low emissions and peak in-cylinder pressures inherent in homogeneous charge compression ignition engines.",1,https://api.osf.io/v2/files/5925d715b83f69026114b32d/,837,https://engrxiv.org/xywbc/,10.31224/osf.io/xywbc,,2017-05-24T18:58:15.979870,2018-07-02T10:58:10.675274 | |
| e6qdr,"Investigation of Biofuels from Microorganism Metabolism for Use as Anti-Knock Additives","This paper investigates the anti-knock properties of biofuels that can be produced from microorganism metabolic processes. The biofuels are rated using Research Octane Number (RON) and Blending Research Octane Number (BRON), which determine their potential as additives for fuel in spark ignition (SI) engines. Tests were conducted using a single-cylinder Cooperative Fuel Research (CFR) engine and performance of the biofuels was compared to primary reference fuels (PRFs). The investigated fuels include 3-methyl-2-buten-1-ol, 3-methyl-3-buten-1-ol, 2-methylpropan-1-ol (isobutanol), and limonene. Results show that 3-methyl-2-buten-1-ol, 3-methyl-3-buten-1-ol, and 2-methylpropan-1-ol (isobutanol) sufficiently improve the anti-knock properties of gasoline.",1,https://api.osf.io/v2/files/592458ee6c613b024fad2cdd/,739,https://engrxiv.org/e6qdr/,10.31224/osf.io/e6qdr,10.1016/j.fuel.2013.10.024,2017-05-23T15:51:07.523619,2018-07-02T10:58:10.222532 | |
| 5v7r9,"Predicting the Cetane Number of Furanic Biofuel Candidates Using an Improved Artificial Neural Network Based on Molecular Structure","The next generation of alternative fuels is being investigated through advanced chemical and biological production techniques for the purpose of finding suitable replacements to diesel and gasoline while lowering production costs and increasing process yields. Chemical conversion of biomass to fuels provides a plethora of pathways with a variety of fuel molecules, both novel and traditional, which may be targeted. In the search for new fuels, an initial, intuition-driven evaluation of fuel compounds with desired properties is required. Due to the high cost and significant production time needed to synthesize these materials at a scale sufficient for exhaustive testing, a predictive model would allow chemists to preemptively screen fuel properties of potentially desirable fuel candidates. Recent work has shown that predictive models, in this case artificial neural networks (ANN’s) analyzing quantitative structure property relationships (QSPR’s), can predict the cetane number (CN) of a proposed fuel molecule with relatively small error. A fuel’s CN is a measure of its ignition quality, typically defined using prescribed ASTM standards and a cetane testing engine. Alternatively, the analogous derived cetane number (DCN), obtained using an Ignition Quality Tester (IQT), is a direct measurement alternative to the CN that uses an empirical inverse relationship to the ignition delay found in the constant volume combustion chamber apparatus. DCN data points acquired using an IQT were utilized for model validation and expansion of the experimental database used in this study. The present work improves on an existing model by optimizing the model architecture along with the key learning variables of the ANN and by making the model more generalizable to a wider variety of fuel candidate types, specifically the class of furans and furan derivatives, by including specific molecules for the model to incorporate. The new molecules considered include tetrahydrofuran, 2-methylfuran, 2-methyltetrahydrofuran, 5,5'-(furan-2-ylmethylene)bis(2-methylfuran), 5,5'-((tetrahydrofuran-2-yl)methylene)bis(2-methyltetrahydrofuran), tris(5-methylfuran-2-yl)methane, and tris(5-methyltetrahydrofuran-2-yl)methane. Model architecture adjustments improved the overall root-mean-squared error (RMSE) of the base database predictions by 5.54%. Additionally, through the targeted database expansion, it is shown that the predicted cetane number of the furan-based molecules improves on average by 49.21% (3.74 CN units) and significantly for a few of the individual molecules. This indicates that a selected subset of representative molecules can be used to extend the model’s predictive accuracy to new molecular classes. The approach, bolstered by the improvements presented in this paper, enables chemists to focus on promising molecules by eliminating less favorable candidates in relation to their ignition quality.",1,https://api.osf.io/v2/files/591ddf03594d90024db699c0/,697,https://engrxiv.org/5v7r9/,10.31224/osf.io/5v7r9,10.1115/ICEF2016-9383,2017-05-18T17:59:07.909545,2018-07-02T10:58:09.213087 | |
| w5ebh,"Mixedness Measurement in Gaseous Jet Injection","In turbulent non-premixed combustion applications, such as diesel and direct injection engines, the mixedness of the injected fuel with oxygen and the working fluid inside the combustion chamber is a crucial parameter since it can significantly affect the ignition behavior. In this study, a comprehensive method for investigating mixedness, defined by spatial variation and scalar dissipation, is implemented to assess the turbulent injection of hydrogen into mixture of oxygen with nitrogen, argon, and xenon. Evaluating both criteria reflects the mixture homogeneity as well as local gradients, which aids in discriminating scalar distributions with identical homogeneity and different patterns. The results indicate that replacing nitrogen with argon as the working fluid can provide more suitable ignition conditions for the hydrogen jet.",1,https://api.osf.io/v2/files/591dd587594d90024eb69238/,555,https://engrxiv.org/w5ebh/,10.31224/osf.io/w5ebh,,2017-05-18T17:19:22.369310,2018-07-02T10:58:09.174998 | |
| 94s8d,"The Effect of Heavy Working Fluids on Hydrogen Combustion","The thermodynamic efficiency of internal combustion engines is dependent on the compression ratio and specific heat ratio of the working fluid. Using a mixture of oxygen and noble gases instead of air can increase the thermal efficiency due to their higher specific heat ratio. It also has advantage of eliminating NOx caused by lack of nitrogen. In this study, the three dimensional turbulent injection of hydrogen into a constant volume combustion chamber has been modeled and compared to mixtures of oxygen with nitrogen, argon and xenon. All conditions including the mass flow rate of the injected fuel, injection velocity, and initial temperature and pressure of the chamber were kept constant. The results indicate that the hydrogen jet has more penetration length in nitrogen compared to argon and xenon. However, the smaller penetration lengths lead to more complex jet shapes and larger cone angles. In combination with the higher specific heat ratio, combustion in a noble gas environment results in higher temperatures and OH radical concentrations. Furthermore, mixedness is investigated using mean spatial variation and mean scalar dissipation. Hydrogen in argon shows a better mixing rate compared to nitrogen and xenon due to higher diffusivity.",1,https://api.osf.io/v2/files/591cb0bf6c613b024ed1179d/,862,https://engrxiv.org/94s8d/,10.31224/osf.io/94s8d,,2017-05-17T20:27:59.944289,2018-07-02T10:58:08.805543 | |
| 753nx,"Simulation-based study of the energy requirements linked to the temperature control of micro-algae culture in outdoor photobioreactors.","Outdoor microalgae photobioreactors are exposed to continuously variable weather conditions, causing permanent fluctuations of culture temperature that must be limited within a strain-dependent range. The optimization of photobioreactor performance requires to be able to predict the culture temperature evolution and related power requirements as a function of weather conditions as well as photobioreactor design. Based on this perspective, a thermal model for vertical tubular photobioreactors was proposed and validated using experimental data from industrial-scale photobioreactors. The model was then used to predict the annual amount of energy required to maintain the culture temperature within a desired range, for different reactor configurations and for several locations in the world. The use of weather databases is of major importance to choose the best location to build microalgae production facilities and to optimize influent geometrical and operating parameters, which can play wanted or unwanted roles depending on the meteorological conditions of the site.",1,https://api.osf.io/v2/files/591ad953b83f69024e1b9caa/,537,https://engrxiv.org/753nx/,10.31224/osf.io/753nx,,2017-05-16T11:20:24.618879,2018-07-02T10:58:08.289158 | |
| 5e6py,"Pressure Password Door Lock","Our project was to create an assistive technology device that would help someone with a disability. Our group chose to create a device that could attach to a door's dead bolt and be unlocked with a series of different amounts of pressure,",1,https://api.osf.io/v2/files/591533fd594d90025035c53f/,340,https://engrxiv.org/5e6py/,10.31224/osf.io/5e6py,,2017-05-12T04:08:03.436071,2018-07-02T10:58:06.564791 | |
| wcb4a,"Malawi Drive System","A Pelton wheel drive system for a hydroelectric turbine",1,https://api.osf.io/v2/files/59135bba6c613b0259aad557/,219,https://engrxiv.org/wcb4a/,10.31224/osf.io/wcb4a,,2017-05-10T18:30:25.620071,2018-07-02T10:56:51.545420 | |
| hcj62,"Chain and Sprocket Hydro Generator Drive System","This project aims to bring power to rural towns in Malawi through the use of a micro hydro generator. Currently only about 11% of rural Malawi have electrical power access according to the world bank, sustainable energy for all database. The rugged terrain makes it ideal for hydro power. Near Hastings Mkandawire village is a small river which is diverted through plastic pipes. These pipes are plumbed downhill, this allows Hastings to increase the pressure of the water. At the bottom of the hill the water is directed at a water wheel on a shaft hooked up to a small generator. Hastings Mkandawire is the man who started the company Magnetic Power Company who is responsible for building these small generators. Hastings started by converting motor casings and other scrap materials into Nano-hydro-generators. What Hastings would like to have in his future design is sand casted key parts so generators can be mass produced. Hastings and his business want to spread access of electricity in his community and other small towns. We are going to aid in this process by helping to design a drive system that maximizes the performance measured as electrical power output for a flow of water.",1,https://api.osf.io/v2/files/59135330594d90025ae11d2a/,325,https://engrxiv.org/hcj62/,10.31224/osf.io/hcj62,,2017-05-10T17:54:18.729215,2018-07-02T10:56:51.510615 | |
| h85vn,"ET-332 Project Presentation Slides","These slides represent the project that we did for creating a mechanical system that would be placed onto a pre-existing hydroelectric generator system.",1,https://api.osf.io/v2/files/5913276ab83f6902517557a7/,281,https://engrxiv.org/h85vn/,10.31224/osf.io/h85vn,,2017-05-10T14:46:22.896226,2018-07-02T10:56:51.241107 | |
| 2s9fz,"ET-332 Mechanical Project","This document was created to design a mechanical advantage for a pre-existing hydroelectric generator setup.",1,https://api.osf.io/v2/files/591326996c613b0259aac639/,91,https://engrxiv.org/2s9fz/,10.31224/osf.io/2s9fz,,2017-05-10T14:44:05.378109,2018-07-02T10:56:51.209116 | |
| fvsyu,"Malawi Power Transfer System","This is a power transfer system created to help upgrade electrical power generation in Malawi.",1,https://api.osf.io/v2/files/59131fedb83f69024e75556a/,245,https://engrxiv.org/fvsyu/,10.31224/osf.io/fvsyu,,2017-05-10T14:14:57.106861,2018-07-02T10:56:51.176107 | |
| gjev4,"Malawi Nano-hydro electric generator","Nano-hydro electric generator utilizing a casted aluminum pulley system",1,https://api.osf.io/v2/files/59131e7ab83f69024f754a4c/,239,https://engrxiv.org/gjev4/,10.31224/osf.io/gjev4,,2017-05-10T14:11:20.578975,2018-07-02T10:56:51.142478 | |
| 7h4yq,"Malawi Hydro Generator Chain and Sprocket","Malawi Hydro Generator Chain and Sprocket",1,https://api.osf.io/v2/files/59131de9b83f69024f754a27/,299,https://engrxiv.org/7h4yq/,10.31224/osf.io/7h4yq,,2017-05-10T14:06:00.405399,2018-07-02T10:56:51.102171 | |
| sdfb2,"Malawi Hydro-Generator Project","Malawi Hydro Generator",1,https://api.osf.io/v2/files/59131dde594d900258e107b5/,261,https://engrxiv.org/sdfb2/,10.31224/osf.io/sdfb2,,2017-05-10T14:06:11.265090,2018-07-02T10:56:51.069233 | |
| 23pra,"Grabbin' Pills Report","This report is on a pill dispensing device made for our Impacts of Engineering course (Etech 100) at University of Wisconsin- Stout in Spring of 2017.",1,https://api.osf.io/v2/files/591118719ad5a1024e5d3f02/,103,https://engrxiv.org/23pra/,10.31224/osf.io/23pra,,2017-05-09T01:34:13.632765,2018-07-02T10:56:50.144729 | |
| xap7y,"Adaptive Door Handle","ETECH-100 Project. | |
| Adaptive door handle for wrist impinged patients.",1,https://api.osf.io/v2/files/59110d5e9ad5a1024f5d3c87/,268,https://engrxiv.org/xap7y/,10.31224/osf.io/xap7y,,2017-05-09T00:31:25.542720,2018-07-02T10:56:50.110430 | |
| a9xgp,"Automatic Pill Dispenser","College project created at the University Of Wisconsin-Stout.",1,https://api.osf.io/v2/files/5910a4029ad5a1025d675b26/,314,https://engrxiv.org/a9xgp/,10.31224/osf.io/a9xgp,,2017-05-08T17:10:51.804316,2018-07-02T10:56:49.822939 | |
| 5g6mt,"Arduino Hulk","We were tasked with providing an assistive technology of some kind using Arduino technology. We settled on using a hulk action figure and connecting to an array of switches. These switches would then, once set in a certain order, make the action figure do the ""hulk smash"".",1,https://api.osf.io/v2/files/59106ef4594d90024effe057/,483,https://engrxiv.org/5g6mt/,10.31224/osf.io/5g6mt,,2017-05-08T13:26:02.378811,2018-07-02T10:56:49.659857 | |
| edypr,"Cabinet Door Opener","People who are to short or are physically disabled and are not able to reach and open a cabinet door in either a kitchen or shop.",1,https://api.osf.io/v2/files/59106cf7b83f69024e73d0ad/,420,https://engrxiv.org/edypr/,10.31224/osf.io/edypr,,2017-05-08T13:09:59.210249,2018-07-02T10:56:49.615947 | |
| y5bzp,"ETECH-100 project","Automated blinds for limited mobility people",1,https://api.osf.io/v2/files/590fdf07594d90024dffc043/,138,https://engrxiv.org/y5bzp/,10.31224/osf.io/y5bzp,,2017-05-08T03:01:12.625125,2018-07-02T10:56:49.518119 | |
| wka3p,"Final Report","Final Report for Impacts 100",1,https://api.osf.io/v2/files/590fcb94b83f69024f73c657/,95,https://engrxiv.org/wka3p/,10.31224/osf.io/wka3p,,2017-05-08T01:40:17.770853,2018-07-02T10:56:49.486427 | |
| 329du,"Is sulfide stress cracking an anodic or a cathodic process?","Is sulfide stress cracking an anodic or a cathodic process? Does hydrogen play a role or is SSC controlled by anodic dissolution?",1,https://api.osf.io/v2/files/590c67dbb83f69025597aee6/,671,https://engrxiv.org/329du/,10.31224/osf.io/329du,,2017-05-05T11:55:29.195865,2019-10-14T00:00:15.955847 | |
| u4em9,"Virtual classroom project","This project aims to provide students with disabilities the same in class learning experience through virtual reality technology, 360-degree video capture, and the use of Arduino units. These technologies will be combined to facilitate communication between teachers in physical classrooms with students in virtual classrooms. The goal is to provide a person who is affected by a disability (which makes it hard to be in a traditional classroom) the same benefits of a safe and interactive learning environment.",1,https://api.osf.io/v2/files/590b983db83f69024db02740/,329,https://engrxiv.org/u4em9/,10.31224/osf.io/u4em9,,2017-05-04T21:11:03.067629,2018-07-02T10:56:48.719540 | |
| 53rke,"Evaluating the academic trend of RFID technology based on SCI and SSCI publications from 2001 to 2014","Radio frequency identification (RFID) is one of the most influential technologies of the twenty-first century. Today, RFID technology is being applied in a wide array of disciplines in science research and industrial projects. The significant impact of RFID is clearly visible by the rate of academic publications in the last few years. This article surveys the literature to evaluate the trend of RFID technology development based on academic publications from 2001 to 2014. Both bibliometric and content analyses are applied to examine this topic in SCI-Index and SSCI-Index documents. Based on the bibliometric technique, all 5159 existing RFID documents are investigated and several important factors are reviewed, including contributions by country, organizations, funding agencies, journal title, authors, research area and Web of Science category. Moreover, content analysis is applied to the top 100 most cited documents and based on their contents, these top 100 documents are classified into four different categories with each category divided in several sub-categories. This research aims to i |
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