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Articles 50911 - 50940 of 197010

Full-Text Articles in Engineering

Directional Link Management Using In-Band Full-Duplex Free Space Optical Transceivers For Aerial Nodes, A F M Saniul Haq Jan 2021

Directional Link Management Using In-Band Full-Duplex Free Space Optical Transceivers For Aerial Nodes, A F M Saniul Haq

Electronic Theses and Dissertations, 2020-2023

Free-space optical (FSO) communication has become very popular for wireless applications to complement and, in some cases, replace legacy radio-frequency for advantages like unlicensed band, spatial reuse, and enhanced security. Even though FSO can achieve very high bit-rate (tens of Gbps), range limitation due to high attenuation and weather dependency has always restricted its practical implementation to indoor application like data centers and outdoor application like Project Loon. Building-to-building communication, smart cars, and airborne drones are potential futuristic wireless communication sectors for mobile ad-hoc FSO networking. Increasing social media usage demands high-speed mobile connectivity for applications like video call and …

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Scalable Online Vetting Of Android Apps For Measuring Declared Sdk Versions And Their Consistency With Api Calls, Daoyuan Wu, Debin Gao, David Lo Jan 2021

Scalable Online Vetting Of Android Apps For Measuring Declared Sdk Versions And Their Consistency With Api Calls, Daoyuan Wu, Debin Gao, David Lo

Research Collection School Of Computing and Information Systems

Android has been the most popular smartphone system with multiple platform versions active in the market. To manage the application’s compatibility with one or more platform versions, Android allows apps to declare the supported platform SDK versions in their manifest files. In this paper, we conduct a systematic study of this modern software mechanism. Our objective is to measure the current practice of declared SDK versions (which we term as DSDK versions afterwards) in real apps, and the (in)consistency between DSDK versions and their host apps’ API calls. To successfully analyze a modern dataset of 22,687 popular apps (with an …

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Microstructural Development Of Inconel 625 Nickel-Based Superalloy As Function Of Laser Powder Bed Fusion Parameters, Sofia Nucci Jan 2021

Microstructural Development Of Inconel 625 Nickel-Based Superalloy As Function Of Laser Powder Bed Fusion Parameters, Sofia Nucci

Electronic Theses and Dissertations, 2020-2023

Additive manufacturing (AM) allows fabrication of complex components with features that are impractical or impossible to achieve through conventional methods. Selective laser melting (SLM) powder bed fusion AM technology was selected for this study on Inconel 625, a widely utilized high-temperature alloy that is hard to machine. The present work investigates impact of laser power and scanning speed variations on the resulting characteristics of fabricated IN625 samples. Gas atomized metallic alloy powders were acquired and analyzed through laser diffraction to verify acceptable size distribution. Cubic samples were built with a range of laser scan speeds in 200 mm/s intervals for …

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Corticomuscular Adaptation To Mechanical Perturbations In A Seated Locomotor Task, Seyed Yahya Shirazi Jan 2021

Corticomuscular Adaptation To Mechanical Perturbations In A Seated Locomotor Task, Seyed Yahya Shirazi

Electronic Theses and Dissertations, 2020-2023

Cortical control during walking is most pronounced when the person is perturbed. Although seated locomotor tasks such as cycling or recumbent stepping improve walking performance, the electrocortical correlates of perturbed seated tasks have not been studied in detail. The primary purpose of this research was to quantify cortical and muscular responses to mechanical perturbations during recumbent stepping. We also aimed to quantify possible differences between young and older adults' responses to perturbed stepping. A secondary aim of this research was to determine the accuracy of electroencephalography (EEG) source imaging to interpret the electrocortical findings adequately. We hypothesized that both young …

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On The Interaction Of Creep And High-Cycle Fatigue In Cm 247 Lc, Thomas Bouchenot Jan 2021

On The Interaction Of Creep And High-Cycle Fatigue In Cm 247 Lc, Thomas Bouchenot

Electronic Theses and Dissertations, 2020-2023

Industrial gas turbines constitute a considerable portion of global power generation, from large engines for centralized grids, to smaller frames for decentralized demand. Power output, efficiency, and reliability are chief criteria regarding the development of next-generation turbines, whose components are expected to operate in ever harsher environments. Turbine blades are subjected to high temperatures, an array of mechanical loads, and dynamic fluid fields, all contained within a non-isothermal profile, making creep and high-cycle fatigue critical aspects of turbine blade design. Current analysis tools and methods have resulted in the development of many successful components; however, improved life prediction models with …

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The Use Of Physically Based Models And Ensemble Forecasting For Storm Surge Risk Assessment In A Changing Climate, Jeane Camelo Jan 2021

The Use Of Physically Based Models And Ensemble Forecasting For Storm Surge Risk Assessment In A Changing Climate, Jeane Camelo

Electronic Theses and Dissertations, 2020-2023

Storm surge has been the deadliest and costliest hurricane induced hazard in the coastal United States. In order to save property and lives, emergency managers must issue advisories guided by numerical models in a timely manner. However, these surge models are highly dependent on weather forecasts which contain uncertainties themselves as hurricanes traverse through the waters before making landfall. This dissertation aims to understand the contribution of uncertainties in hurricane properties, particularly the wind intensity which can contribute to uncertainties in storm surge models. Investigating these properties through numerical modeling is both computationally and time intensive. However by developing a …

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Engineering Thermostable Regulators For Inducible Gene Expression In Thermophiles, Connor M. Joyce Jan 2021

Engineering Thermostable Regulators For Inducible Gene Expression In Thermophiles, Connor M. Joyce

Honors Theses and Capstones

Thermophilic bacteria have attracted research interest due to their ability to grow at high temperatures ranging from 45 °C to 75 °C with some extreme thermophiles able to survive nearly boiling temperatures. They are valuable sources of thermostable biocatalysts and many have great potential as industrial hosts for biofuel production because fermentation at high temperatures has advantages such as reduced processing costs and lower risk of contamination compared with mesophilic bacteria. For example, some Geobacillus species has been shown to have high solvent tolerance, making them good candidates as host for alcohol production. To develop them as industrial hosts, large …

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Development And Implementation Of A Pressure-Temperature Control System For The Physical Vapor Deposition Of Copper And Niobium From A Molybdenum Filament In The Development Of Superconducting 3d Printed Rf Cavity Particle Accelerators, Chandler J. Fleuette Jan 2021

Development And Implementation Of A Pressure-Temperature Control System For The Physical Vapor Deposition Of Copper And Niobium From A Molybdenum Filament In The Development Of Superconducting 3d Printed Rf Cavity Particle Accelerators, Chandler J. Fleuette

Honors Theses and Capstones

This report covers the development of the pressure-temperature control system used in the production of small superconducting RF cavities for particle accelerators. To test the validity of the created program, a model for the process was created and tested. The model was used to fine tune the control system before integrating it into the lab. The end goal of the control system is to measure the pressure inside of a deposition vacuum chamber, convert that pressure to a temperature, and use that temperature in tandem with a PID controller to control the current passing though a molybdenum filament which is …

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A Meta-Gradient Approach To Learning Cooperative Multi-Agent Communication Topology, Qi Zhang, Dingyang Chen Jan 2021

A Meta-Gradient Approach To Learning Cooperative Multi-Agent Communication Topology, Qi Zhang, Dingyang Chen

Publications

In cooperative multi-agent reinforcement learning (MARL), agents often can only partially observe the environment state, and thus communication is crucial to achieving coordination. Communicating agents must simultaneously learn to whom to communicate (i.e., communication topology) and how to interpret the received message for decision-making. Although agents can efficiently learn communication interpretation by end-to-end backpropagation, learning communication topology is much trickier since the binary decisions of whether to communicate impede end-to-end differentiation. As evidenced in our experiments, existing solutions, such as reparameterization tricks and reformulating topology learning as reinforcement learning, often fall short. This paper introduces a meta-learning framework that aims …

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Celestite Upgrading By Jigs In Presence Of Steel Balls As Ragging Material, Ahmed Sobhy, Ayman A. El-Midany, Suzan S. Ibrahim Jan 2021

Celestite Upgrading By Jigs In Presence Of Steel Balls As Ragging Material, Ahmed Sobhy, Ayman A. El-Midany, Suzan S. Ibrahim

Mining Engineering Faculty Research & Creative Works

Gravity separation using jigs is widely used for coarse particle sizes separation. However, fine sizes reduce jig performance. In this study, the upgrading of celestite ore by jig was investigated at different size fractions in the presence of ragging material. Three size fractions, i.e., -15+2 mm, - 2.0 + 0.50 mm and - 0.50 + 0.08 mm were used. The steel balls were used, as ragging material, to improve the separation of fines as well as to improve the concentrate quality. The statistical design was used to correlate celestite grade and recovery with studied operating variables, i.e., the ragging number …

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Decoupling Of Antennas With Adjacent Frequency Bands, Min Li, Lijun Jiang, Lawrence Kwan Yeung Jan 2021

Decoupling Of Antennas With Adjacent Frequency Bands, Min Li, Lijun Jiang, Lawrence Kwan Yeung

Electrical and Computer Engineering Faculty Research & Creative Works

A decoupling device called cascaded power dividing decoupling network (C-PDDN) is presented for two antennas operating in adjacent frequency bands. Design formulas are derived to determine parametrical variables for high isolation. A prototype of a testing array consisting of two base-station dipole antennas is realized on a Rogers PCB for demonstration purposes. Simulated and experimental results show that good impedance matching, and high isolation are achieved simultaneously after adopting the C-PDDN.

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Data-Driven Identification Of Governing Partial Differential Equations For The Transmission Line Systems, Yanming Zhang, Lijun Jiang Jan 2021

Data-Driven Identification Of Governing Partial Differential Equations For The Transmission Line Systems, Yanming Zhang, Lijun Jiang

Electrical and Computer Engineering Faculty Research & Creative Works

Discovering governing equations for transmission line is essential for the study on its properties, especially when the nonlinearity is introduced in a transmission line system. In this paper, we propose a novel data-driven approach for deriving the governing partial differential equations based on the spatial-temporal samples of current and voltage in the transmission line system. The proposed method is based on the ridge regression algorithm to determine the active spatial differential terms from the candidate library that includes nonlinear functions, in which the time and spatial derivatives are estimated by using polynomial interpolation. Three examples, including uniform and nonuniform transmission …

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Development And Characterization Of Nb₃N/Al₂0₃ Superconducting Multilayers For Particle Accelerators, Chris Sundahl, Junki Makita, Paul B. Welander, Yi-Feng Su, Fumitake Kametani, Lin Xie, Huimin Zhang, Lian Li, Alex Gurevich, Chang-Beom Eom Jan 2021

Development And Characterization Of Nb₃N/Al₂0₃ Superconducting Multilayers For Particle Accelerators, Chris Sundahl, Junki Makita, Paul B. Welander, Yi-Feng Su, Fumitake Kametani, Lin Xie, Huimin Zhang, Lian Li, Alex Gurevich, Chang-Beom Eom

Physics Faculty Publications

Superconducting radio-frequency (SRF) resonator cavities provide extremely high quality factors > 1010 at 1-2 GHz and 2 K in large linear accelerators of high-energy particles. The maximum accelerating field of SRF cavities is limited by penetration of vortices into the superconductor. Present state-of-the-art Nb cavities can withstand up to 50 MV/m accelerating gradients and magnetic fields of 200-240 mT which destroy the low-dissipative Meissner state. Achieving higher accelerating gradients requires superconductors with higher thermodynamic critical fields, of which Nb3Sn has emerged as a leading material for the next generation accelerators. To overcome the problem of low vortex penetration …

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Electroosmotic Flow Of Viscoelastic Fluid Through A Constriction Microchannel, Jianyu Ji, Shizhi Qian, Zhaohui Liu Jan 2021

Electroosmotic Flow Of Viscoelastic Fluid Through A Constriction Microchannel, Jianyu Ji, Shizhi Qian, Zhaohui Liu

Mechanical & Aerospace Engineering Faculty Publications

Electroosmotic flow (EOF) has been widely used in various biochemical microfluidic applications, many of which use viscoelastic non-Newtonian fluid. This study numerically investigates the EOF of viscoelastic fluid through a 10:1 constriction microfluidic channel connecting two reservoirs on either side. The flow is modelled by the Oldroyd-B (OB) model coupled with the Poisson–Boltzmann model. EOF of polyacrylamide (PAA) solution is studied as a function of the PAA concentration and the applied electric field. In contrast to steady EOF of Newtonian fluid, the EOF of PAA solution becomes unstable when the applied electric field (PAA concentration) exceeds a critical value for …

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Mechanism For The Unfolding Of The Top7 Protein In Steered Molecular Dynamics Simulations As Revealed By Mutual Information Analysis, Ognjen Perišić, Willy Wriggers Jan 2021

Mechanism For The Unfolding Of The Top7 Protein In Steered Molecular Dynamics Simulations As Revealed By Mutual Information Analysis, Ognjen Perišić, Willy Wriggers

Mechanical & Aerospace Engineering Faculty Publications

We employed mutual information (MI) analysis to detect motions affecting the mechanical resistance of the human-engineered protein Top7. The results are based on the MI analysis of pair contact correlations measured in steered molecular dynamics (SMD) trajectories and their statistical dependence on global unfolding. This study is the first application of the MI analysis to SMD forced unfolding, and we furnish specific SMD recommendations for the utility of parameters and options in the TimeScapes package. The MI analysis provided a global overview of the effect of perturbation on the stability of the protein. We also employed a more conventional trajectory …

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A Phewas Model Of Autism Spectrum Disorder, John Matta, Daniel Dobrino, Swade Howard, Dacosta Yeboah, Jonathan Kopel, Yasser El-Manzalawy, Tayo Obafemi-Ajayi Jan 2021

A Phewas Model Of Autism Spectrum Disorder, John Matta, Daniel Dobrino, Swade Howard, Dacosta Yeboah, Jonathan Kopel, Yasser El-Manzalawy, Tayo Obafemi-Ajayi

Electrical and Computer Engineering Faculty Research & Creative Works

Children with Autism Spectrum Disorder (ASD) exhibit a wide diversity in type, number, and severity of social deficits as well as communicative and cognitive difficulties. It is a challenge to categorize the phenotypes of a particular ASD patient with their unique genetic variants. There is a need for a better understanding of the connections between genotype information and the phenotypes to sort out the heterogeneity of ASD. In this study, single nucleotide polymorphism (SNP) and phenotype data obtained from a simplex ASD sample are combined using a PheWAS-inspired approach to construct a phenotype-phenotype network. The network is clustered, yielding groups …

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Design Of A 10 Mev Beamline At The Upgraded Injector Test Facility For E-Beam Irradiation, Xi Li, Helmut Baumgart, Gianluigi Ciovati, F.E. Hannon, S. Wang Jan 2021

Design Of A 10 Mev Beamline At The Upgraded Injector Test Facility For E-Beam Irradiation, Xi Li, Helmut Baumgart, Gianluigi Ciovati, F.E. Hannon, S. Wang

Electrical & Computer Engineering Faculty Publications

Electron beam irradiation near 10 MeV is suitable for wastewater treatment. The Upgraded Injector Test Facility (UITF) at Jefferson Lab is a CW superconducting linear accelerator capable of providing an electron beam of energy up to 10 MeV and up to 100 µA current. This contribution presents the beam transport simulations for a beamline to be used for the irradiation of wastewater samples at the UITF. The simulations were done using the code General Particle Tracer with the goal of obtaining an 8 MeV electron beam of radius (3-σ) of ~2.4 cm. The achieved energy spread is ~74.5 keV. The …

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One-Dimensional Lateral Force Anisotropy At The Atomic Scale In Sliding Single Molecules On A Surface, Yuan Zhang, Daniel J. Trainer, Badri Narayanan, Yang Li, Anh T. Ngo, Sushila Khadka, Arnab Neogi, Brandon Fisher, Larry A. Curtiss, Subramanian K.R.S. Sankaranarayanan, Saw Wai Hla Jan 2021

One-Dimensional Lateral Force Anisotropy At The Atomic Scale In Sliding Single Molecules On A Surface, Yuan Zhang, Daniel J. Trainer, Badri Narayanan, Yang Li, Anh T. Ngo, Sushila Khadka, Arnab Neogi, Brandon Fisher, Larry A. Curtiss, Subramanian K.R.S. Sankaranarayanan, Saw Wai Hla

Physics Faculty Publications

Using a q+ atomic force microscopy at low temperature, a sexiphenyl molecule is slid across an atomically flat Ag(111) surface along the direction parallel to its molecular axis and sideways to the axis. Despite identical contact area and underlying surface geometry, the lateral force required to move the molecule in the direction parallel to its molecular axis is found to be about half of that required to move it sideways. The origin of the lateral force anisotropy observed here is traced to the one-dimensional shape of the molecule, which is further confirmed by molecular dynamics simulations. We also demonstrate that …

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In Situ Recrystallization Of Co-Evaporated Cu(In,Ga)Se2 Thin Films By Copper Chloride Vapor Treatment Towards Solar Cell Applications, Deewakar Poudel, Benjamin Belfore, Tasnuva Ashrafee, Elizabeth Palmiotti, Shankar Karki, Grace Rajan, Thomas Lepetit, Angus Rockett, Sylvain Marsillac Jan 2021

In Situ Recrystallization Of Co-Evaporated Cu(In,Ga)Se2 Thin Films By Copper Chloride Vapor Treatment Towards Solar Cell Applications, Deewakar Poudel, Benjamin Belfore, Tasnuva Ashrafee, Elizabeth Palmiotti, Shankar Karki, Grace Rajan, Thomas Lepetit, Angus Rockett, Sylvain Marsillac

Applied Research Center Publications

Cu(In,Ga)Se2 (or CIGS) thin films and devices were fabricated using a modified three-stage process. Using high deposition rates and a low temperature during the process, a copper chloride vapor treatment was introduced in between the second and third stages to enhance the films properties. X-ray diffraction and scanning electron microscopy demonstrate that drastic changes occur after this recrystallization process, yielding films with much larger grains. Secondary ion mass spectrometry shows that the depth profile of many elements is not modified (such as Cu, In and Se) while others change dramatically (such as Ga and Na). Because of the competing …

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Effect Of Random Pinning On Nonlinear Dynamics And Dissipation Of A Vortex Driven By A Strong Microwave Current, W.P.M.R. Pathirana, Alex Gurevich Jan 2021

Effect Of Random Pinning On Nonlinear Dynamics And Dissipation Of A Vortex Driven By A Strong Microwave Current, W.P.M.R. Pathirana, Alex Gurevich

Physics Faculty Publications

We report numerical simulations of a trapped elastic vortex driven by a strong ac magnetic field H(t)=Hsinωt parallel to the surface of a superconducting film. The surface resistance and the power dissipated by an oscillating vortex perpendicular to the film surface were calculated as functions of H and ω for different spatial distributions, densities, and strengths of pinning centers, including bulk pinning, surface pinning, and cluster pinning. Our simulations were performed for both the Bardeen-Stephen viscous vortex drag and the Larkin-Ovchinnikov (LO) drag coefficient η(v) decreasing with the vortex velocity v. The local residual surface resistance Ri(H) …

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Inverted Geometry Ceramic Insulators In High Voltage Dc Electron Guns For Accelerators, C. Hernandez-Garcia, G. Palacios-Serrano, P. Adderley, D. Bullard, J. Grames, Md. Abdullah Mamun, M. Poelker, M. Stutzman, R. Suleiman, Y. Wang, S.A.K. Wijethunga Jan 2021

Inverted Geometry Ceramic Insulators In High Voltage Dc Electron Guns For Accelerators, C. Hernandez-Garcia, G. Palacios-Serrano, P. Adderley, D. Bullard, J. Grames, Md. Abdullah Mamun, M. Poelker, M. Stutzman, R. Suleiman, Y. Wang, S.A.K. Wijethunga

Physics Faculty Publications

A direct current (dc) high voltage photo-emission electron gun operating at 130 kV is utilized at the Jefferson Lab (JLab) Continuous Electron Beam Accelerator Facility to generate spin-polarized electrons for nuclear physics experiments. Over the past decade, JLab has tested and implemented inverted-geometry ceramic insulators in photoguns, connecting the cathode electrode in vacuum to the high voltage power supply using commercial high voltage cables. The results of those tests showed that breakdown voltage was increased using triple-point shielding electrodes and bulk-doped insulators that allow charge drainage. This contribution describes ongoing work to develop a robust insulatorcable connector for reliably applying …

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Magnetic Field Sensors For Detection Of Trapped Flux In Superconducting Radio Frequency Cavities, Ishwari Prasad Parajuli, Gianluigi Ciovati, Jean R. Delayen Jan 2021

Magnetic Field Sensors For Detection Of Trapped Flux In Superconducting Radio Frequency Cavities, Ishwari Prasad Parajuli, Gianluigi Ciovati, Jean R. Delayen

Physics Faculty Publications

Superconducting radio frequency (SRF) cavities are fundamental building blocks of modern particle accelerators. They operate at liquid helium temperatures (2–4 K) to achieve very high quality factors (1010–1011). Trapping of magnetic flux within the superconductor is a significant contribution to the residual RF losses, which limit the achievable quality factor. Suitable diagnostic tools are in high demand to understand the mechanisms of flux trapping in technical superconductors, and the fundamental components of such diagnostic tools are magnetic field sensors. We have studied the performance of commercially available Hall probes, anisotropic magnetoresistive sensors, and flux-gate magnetometers with …

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Efficient Solution Of Surface Erosion In Particle-Laden Hypersonic Flows, Andrew Hinkle, Serhat Hosder, Christopher Johnston Jan 2021

Efficient Solution Of Surface Erosion In Particle-Laden Hypersonic Flows, Andrew Hinkle, Serhat Hosder, Christopher Johnston

Mechanical and Aerospace Engineering Faculty Research & Creative Works

The standard approach for simulating hypersonic dust erosion problems using mixed Eulerian-Lagrangian two-phase solvers is too computationally expensive for routine simulations, and particularly for uncertainty quantification (UQ) analyses. To enable these analyses, a new approach for solving this problem with a sparse set of particles is presented and demonstrated on a problem from literature involving the ExoMars Schiaparelli entry vehicle. This new approach, referred to here as the Trajectory Control Volume (TCV) method is verified against traditional approaches based on Monte Carlo, and is shown to require over 3 orders-of-magnitude less samples to obtain the same results. An example UQ …

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Modeling Rack Force For Steering Maneuvers In A Stationary Vehicle, Nilay Kant, Raunav Chitkara, Prerit Pramod Jan 2021

Modeling Rack Force For Steering Maneuvers In A Stationary Vehicle, Nilay Kant, Raunav Chitkara, Prerit Pramod

Mechanical and Aerospace Engineering Faculty Research & Creative Works

A steering system converts circular motion of the steering wheel into yaw motion of the road-wheels. In absence of a steering assist mechanism, the driver torque overcomes the tire-road friction forces, which is transmitted to the steering rack through tie rods attached to the road-wheels. The net force acting on the rack is then transmitted to the steering wheel through mechanical linkages which results in natural haptic feedback, commonly referred to as the steering feel. In an electric/hydraulic power steering, an electro-mechanical actuator applies assist force, which reduces the torque required by the driver. In order to maintain stability of …

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Partial Arc Sampling Receiving Scheme For Demultiplexing Of Orbital Angular Momentum Vortex Beam, Yanming Zhang, Lijun Jiang Jan 2021

Partial Arc Sampling Receiving Scheme For Demultiplexing Of Orbital Angular Momentum Vortex Beam, Yanming Zhang, Lijun Jiang

Electrical and Computer Engineering Faculty Research & Creative Works

Due to the divergence of the orbital angular momentum (OAM) beam, the OAM demultiplexing needs a considerable aperture size to acquire the OAM field information, which brings the challenges to implementation of the receiving end. To tackle this issue, we develop a partial arc sampling receiving (PASR) scheme for demultiplexing of the vortex beams by using the augmented dynamic mode decomposition (A-DMD) approach. Simulation benchmarks are provided to demonstrate the validity of the proposed novel demultiplexing method.

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Model Computation With Second-Order Radiative Transfer Equation For Snow Medium Using Coupled Finite Element Method And Method Of Moment And Relaxed Hierarchical Equivalent Source Algorithm, Hamsalekha A. Kumaresan, H. T. Ewe, Gobi Vetharatnam, Li (Lijun) Jun Jiang Jan 2021

Model Computation With Second-Order Radiative Transfer Equation For Snow Medium Using Coupled Finite Element Method And Method Of Moment And Relaxed Hierarchical Equivalent Source Algorithm, Hamsalekha A. Kumaresan, H. T. Ewe, Gobi Vetharatnam, Li (Lijun) Jun Jiang

Electrical and Computer Engineering Faculty Research & Creative Works

Active microwave remote sensing is essential to monitor the conditions of the environment by analyzing the microwave returns from the earth terrain. Various Computational Electromagnetics (CEM) techniques are implemented to study the backscattering coefficient of numerous earth terrains such as vegetation and snow medium. In this paper, a theoretical model based on second order radiative transfer equation is investigated by incorporating two computational methods which are known as coupled Finite Element Method (FEM) and Method of Moment (MoM), and Relaxed Hierarchical Equivalent Source Algorithm (RHESA). These theoretical models consider three shapes of scatterers which can be used to represent the …

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Hybrid Beamforming With Deep Learning For Large-Scale Antenna Arrays, Rentao Hu, Lijun Jiang, Ping Li Jan 2021

Hybrid Beamforming With Deep Learning For Large-Scale Antenna Arrays, Rentao Hu, Lijun Jiang, Ping Li

Electrical and Computer Engineering Faculty Research & Creative Works

The emergence of highly directional beamforming technology makes millimeter wave frequency band communication possible in future wireless communication networks. Based on the multipath characteristics of millimeter wave frequency communication, a high-precision multipath channel estimation algorithm based on signal subspace is proposed. In the mobile terminal, an iterative heuristic radiofrequency combination algorithm based on spatial points is proposed. The analog precoding at the base station uses deep learning to accelerate the calculation, and then the multi-user communication is modeled to design the digital precoding. The simulation results show that the multi-channel estimation algorithm can estimate 4 paths with an error of …

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Evolution Of Three Streambanks Before And After Stabilization And Record Flooding, Matthew Russell, Aaron R. Mittelstet, Tiffany Messer, Jesse T. Korus, R.M. Joeckel Jan 2021

Evolution Of Three Streambanks Before And After Stabilization And Record Flooding, Matthew Russell, Aaron R. Mittelstet, Tiffany Messer, Jesse T. Korus, R.M. Joeckel

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Stabilization projects are increasingly used to mitigate the effects of anthropogenic streambank erosion, yet the effectiveness of stabilization has been insufficiently measured. Sound monitoring practices inform adjustments in implementation and maintenance, which improve engineered effectiveness. Thus, the objectives of this study were to: 1) measure streambank migration from in three reaches stabilized with wooden jetties following a major flooding event, and 2) quantify deposition around the jetties between pre-flood and post-flood. Streambank deposition was measured in 2019 with a River Surveyor and Global Positioning System (GPS). Bank erosion rates in Reaches 1, 2 and 3 were 0.41, 0.96 and 0.07 …

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Parallel Computation, Mahesh Wosti Jan 2021

Parallel Computation, Mahesh Wosti

Student Academic Conference

Parallel computing has always fascinated me since I became aware of it. I think it is the only path forward if we are to build and make a super-fast computer in days to come. For my senior seminar, I want to build a simple framework of the parallel system and dig deeper into potential benefits and drawbacks of using a parallel system compared to the serial computing that is still pervasive in today’s modern technology.

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Als-Induced Excitability Changes In Individual Motorneurons And The Spinal Motorneuron Network In Sod1-G93a Mice At Symptom Onset, Christiana S.I. Draper Jan 2021

Als-Induced Excitability Changes In Individual Motorneurons And The Spinal Motorneuron Network In Sod1-G93a Mice At Symptom Onset, Christiana S.I. Draper

Browse all Theses and Dissertations

Amyotrophic lateral sclerosis (ALS) is the most common motorneuron (MN) disease in adulthood. ALS is hallmarked by the progressive loss of MNs in the brain, brainstem, and spinal cord. Many hypotheses to explain the pathogenesis of ALS have been explored, but the exact mechanisms underlying the development of this disease remain unknown. However, abnormalities in MN excitability and glutamate excitotoxicity are the most widely studied. For decades, researchers have examined MN excitability in ALS, but the current literature is inconsistent, showing evidence of hyperexcitability, hypoexcitability, or no change in excitability of MNs in ALS. Many of these studies also focus …

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