Open Access. Powered by Scholars. Published by Universities.®

Engineering Commons™

Open Access. Powered by Scholars. Published by Universities.®

University of Texas at Arlington

Discipline
Keyword
Publication Year
Publication
Publication Type
File Type

Articles 1711 - 1740 of 3180

Full-Text Articles in Engineering

Development Of The Duplicate Shear Test For Asphalt Mixtures, Mohammadreza Khajeh Hosseini Jan 2015

Development Of The Duplicate Shear Test For Asphalt Mixtures, Mohammadreza Khajeh Hosseini

Civil Engineering Theses - Archive

Permanent shear deformation is the main cause of rutting in asphalt concrete layers. Therefore, the determination of the shear properties of asphalt mixtures is helpful for predicting the rutting in asphalt pavement structures and for the identification of poor performing asphalt mixtures. The objective of this study was to develop a new test device to replicate similar loading conditions and constraints of the Superpave Shear Tester (SST). The new device, named the Double Shear Tester (DST), determines the mechanical average of the shear properties and responses of two specimens instead of that of a single specimen as in the SST …


Assessing Values-Based Sourcing Strategies In Regional Food Supply Networks: An Agent-Based Approach, Caroline C. Krejci, Michael C. Dorneich, Richard T. Stone Jan 2015

Assessing Values-Based Sourcing Strategies In Regional Food Supply Networks: An Agent-Based Approach, Caroline C. Krejci, Michael C. Dorneich, Richard T. Stone

Industrial, Manufacturing, and Systems Engineering Faculty Publications - Archive

The recent increase in demand for regionally produced food has resulted in a need for more efficient distribution methods. To connect regional food producers and consumers, intermediated regional food supply networks have developed. The intermediary, known as a regional food hub, serves as an aggregation point for products and information. It may also act as a filter to ensure that the requirements of both producers and consumers are consistently met. This paper describes an empirically based agent-based model of a regional food network in central Iowa that is intermediated by a food hub. The model was used to test a …


Adaptive Multiple Optimal Learning Factors For Neural Network Training, Jeshwanth Challagundla Jan 2015

Adaptive Multiple Optimal Learning Factors For Neural Network Training, Jeshwanth Challagundla

Electrical Engineering Theses - Archive

There is always an ambiguity in deciding the number of learning factors that is really required for training a Multi-Layer Perceptron. This thesis solves this problem by introducing a new method of adaptively changing the number of learning factors computed based on error change created per multiply. A new method is introduced for computing learning factors for weights grouped based on the curvature of the objective function. A method for linearly compressing large ill-conditioned Newton's Hessian matrices to smaller well-conditioned ones is shown. This thesis also shows that the proposed training algorithm adapts itself between two other algorithms in order …


System Security, Threat Detection And Prevention Measures Of Autonomous Systems, Chaitanya Rani Veeranna Gowda Jan 2015

System Security, Threat Detection And Prevention Measures Of Autonomous Systems, Chaitanya Rani Veeranna Gowda

Electrical Engineering Theses - Archive

The Federal Aviation Administration (FAA) estimates that by the year 2020, the United States will have over 30,000 drones. Today, the fields of utilization of drones, also known as Unmanned Aerial Vehicles (UAV) are unlimited. UAVs can be used in hazardous military missions, since they exclude the risk factors involved in manned vehicles. The numerous sensors on board gather data related to the desired flight plan. This exposes UAVs to various vulnerabilities since they carry enormous information and raises safety issues and privacy concerns. Absence of manual control by a human operator over the UAV results in fraudulent information being …


Evaluation Of Adaptive Video Optimization For Stall Minimization In Wireless Networks, Karishma Katara Jan 2015

Evaluation Of Adaptive Video Optimization For Stall Minimization In Wireless Networks, Karishma Katara

Electrical Engineering Theses - Archive

Mobile devices such as smart phones and tablets have become an integral part of peoples’ daily lives. Users are consuming more content over wireless networks than ever before, and the largest portion of that traffic by volume is delivered as video. Even with the rollout of high speed LTE networks, subscriber demand for content is growing at an overall faster rate than network capacity is being added in many urban areas. This presents a challenge to the network operators since users expect a stall-free playback experience, on devices that support high resolution and high quality content. To help maintain the …


Self-Similarity And Modeling Of Lte / Lte-A Data Traffic, Roopesh Kumar Polaganga Jan 2015

Self-Similarity And Modeling Of Lte / Lte-A Data Traffic, Roopesh Kumar Polaganga

Electrical Engineering Theses - Archive

The mobile wireless communication system has evolved into its 4th generation with ubiquitous availability assuring higher data rates and reliable communication. To achieve a robust and reliable network, it is necessary to understand the traffic characteristics of the network. In this work, network traffic characteristics like Self-Similarity property and modeling of user arrivals are estimated for real-world LTE & LTE-Advanced (LTE-A) traffic. Lot of work has been done on Self-Similarity of Ethernet and Ad-Hoc Network's data traffic. But Self-Similarity in LTE and LTE-A data traffic has been left un-explored. Real world LTE and LTE-A data traffic collected from a live …


Embedded Data Acquisition Platform For Low Speed Automated Surface Measurements On Asphalt, Joseph Joemon Jose Mullassery Jan 2015

Embedded Data Acquisition Platform For Low Speed Automated Surface Measurements On Asphalt, Joseph Joemon Jose Mullassery

Electrical Engineering Theses - Archive

The study is to be performed with the main goal of analyzing the existing portability and scalability problems of the existing Road profile measurement for TXDOT and improving it by making a system which is much more scalable and portable. Along with the above, another important aspect of this research study is to develop an algorithm using a new technique based on a different type of sensor viz. 3-Axis Accelerometers and compute an estimate for the IRI (International Roughness Index) using the newly obtained data from our research and previously available IRI data from earlier research efforts. The system would …


Cacti- And Shorebirds-Inspired Transports Of Liquid Drops And Two Related Fog Collectors, Xin Heng Jan 2015

Cacti- And Shorebirds-Inspired Transports Of Liquid Drops And Two Related Fog Collectors, Xin Heng

Mechanical and Aerospace Engineering Dissertations - Archive

Motivated by what has been used in cacti and shorebirds to directionally manipulate water drops, we have explored two approaches to guide the movement of liquid drops. Based on these approaches, in addition to separating oil from its mixture with water, we have further developed two fog collectors. The first fog collector has a configuration similar to its counterpart in a cactus. This collector includes a large ZnO wire and an array of small ZnO wires that are branched on the large wire. All these wires have conical shapes, whose diameters gradually increase from the tip to the root of …


Measurements, Modeling, And Simulation Of Semiconductor/Gate Dielectric Defects Using Random Telegraph Signals, Mohamed Assad Nour Jan 2015

Measurements, Modeling, And Simulation Of Semiconductor/Gate Dielectric Defects Using Random Telegraph Signals, Mohamed Assad Nour

Electrical Engineering Dissertations - Archive

Constructing an effective statistical model and a simulation tool that can predict the phenomenon of random telegraph signals (RTS) is the objective of this work. The continuous scaling down of metal oxide – semiconductor field effect transistors (MOSFETs) makes charging/discharging traps(s) located at the silicon/silicon dioxide interface or deep in the oxide bulk by mobile charge(s) a more pronounced problem for both analog and digital applications. The intent of this work is to develop an RTS statistical model and a simulation tool based on first principles and supported by extensive experimental data. The newly developed RTS statistical model and its …


Multisensory Integration For Adaptive Physical Human-Robot Interaction, Isura Ranatunga Jan 2015

Multisensory Integration For Adaptive Physical Human-Robot Interaction, Isura Ranatunga

Electrical Engineering Dissertations - Archive

Automated systems and have become increasingly prevalent in the 21st century. With their increased processing power, personal and home robotics has finally come within reach of the public. For robots to finally work with and around humans there are some challenges to be overcome. Some of these include complex social interaction, safety, identifying human intent, unpredictable physical interaction, and uncertain dynamic environments. This research focuses on safe, robust, and intuitive physical interaction with humans utilizing multiple sensor modalities.In this thesis a solution for adaptive physical human-robot interaction is proposed. The proposed framework consists of three parts. Dynamics compensation: adaptive dynamics …


Optimal Tracking Control Of Uncertain Systems: On-Policy And Off-Policy Reinforcement Learning Approaches, Hamidreza Modares Jan 2015

Optimal Tracking Control Of Uncertain Systems: On-Policy And Off-Policy Reinforcement Learning Approaches, Hamidreza Modares

Electrical Engineering Dissertations - Archive

Over the last few decades, strong connections between reinforcement learning (RL) and optimal control have prompted a major effort towards developing online and model-free RL algorithms to learn the solution to optimal control problems. Although RL algorithms have been widely used to solve the optimal regulation problems, few results considered solving the optimal tracking control problem (OTCP), despite the fact that most real-world control applications are tracking problems. On the other hand, existing methods for solving OTCP require complete knowledge of the system dynamics. This research begins with developing an adaptive optimal algorithm for linear quadratic tracking problem (LQT). A …


Design And Fabrication Of Guided-Mode Resonance Devices, Guoliang Chen Jan 2015

Design And Fabrication Of Guided-Mode Resonance Devices, Guoliang Chen

Electrical Engineering Dissertations - Archive

Guided-mode resonance (GMR) effect based on waveguide grating structure has been attracting plenty of attention in recent years due to its abundant application in energy, information technology, and sensors. This dissertation aims to develop new GMR devices and apply them in the above fields. Initially thermoelectric devices integrated with optical resonance absorbers are demonstrated. We design the absorbers with rigorous numerical methods and fashion experimental prototypes by thin-film deposition, patterning, and etching. A ~2.5-?m-thick p-type heavily doped polysilicon film on a ~2-?m layer of thermally grown SiO2 enables guided-mode resonance. The SiO2 layer additionally serves to thermally insulate the polysilicon …


Revisiting Control Establishments For Emerging Energy Hubs, Vahidreza Nasirian Jan 2015

Revisiting Control Establishments For Emerging Energy Hubs, Vahidreza Nasirian

Electrical Engineering Dissertations - Archive

Emerging small-scale energy systems, i.e., microgrids and smartgrids, rely on centralized controllers for voltage regulation, load sharing, and economic dispatch. However, the central controller is a single-point-of-failure in such a design as either the controller or attached communication links failure can render the entire system inoperable. This work seeks for alternative distributed control structures to improve system reliability and help to the scalability of the system. A cooperative distributed controller is proposed that uses a noise-resilient voltage estimator and handles global voltage regulation and load sharing across a DC microgrid. Distributed adaptive droop control is also investigated as an alternative …


Design And Fabrication Of Iridium Oxide-Based Multi-Electrode Array For Biomedical Applications, Cuong Manh Nguyen Jan 2015

Design And Fabrication Of Iridium Oxide-Based Multi-Electrode Array For Biomedical Applications, Cuong Manh Nguyen

Electrical Engineering Dissertations - Archive

Multi-electrode array (MEA) has emerged as one of the most important and common tools to monitor physiological and biological signals. Advanced micro-electro-mechanical systems (MEMS) and innovative nanofabrication technologies provide means to fabricate micro-scale MEAs for implantable bio-applications. One of the prominent advantages of such miniature electrodes is to minimize tissue damage or injuries during surgical implantation. The micro-scale electrodes are normally coated with materials or functionalized with proteins and enzymes to sense different analyates. Iridium oxide (IrOx) owning with many important traits such as biocompatibility, high corrosion resistance in electrolyte materials, pH-sensitivity, large surface-to-volume ratio, and high charge storage has …


A Lidar-Based Auto Hydro Breakline Generation Algorithm For Standing Water Bodies, George John Toscano Jan 2015

A Lidar-Based Auto Hydro Breakline Generation Algorithm For Standing Water Bodies, George John Toscano

Electrical Engineering Dissertations - Archive

Airborne Light Detection and Ranging (LiDAR) is a sensor that can generate terrain elevation and intensity data of very large areas with high precision and dense resolution. The intensity and elevation are co-registered, which eliminates the need for tedious registration after the fact. This combined LiDAR data can be used to classify different topographic features. Given the enormous amount of such data generated all over the world, total automation in these classification processes in a batch process is highly desired if not a critical need. In this dissertation, a novel LiDAR-based automated standing waterbody extraction (LASWE) algorithm is presented. The …


Embedding Integrated Rfid Sensors Into Fiber Reinforced Plastics During The Manufacturing Process, Billy Joe Gray Jan 2015

Embedding Integrated Rfid Sensors Into Fiber Reinforced Plastics During The Manufacturing Process, Billy Joe Gray

Industrial, Manufacturing, and Systems Engineering Dissertations - Archive

This research evaluates the impact of embedding a Radio Frequency Identification (RFID) tag into the structure of a fiber reinforced polymer (FRP). The first portion of the research evaluates the mechanical impacts of embedding the tag through simulation of the stresses that the polymer will be exposed to and then comparing with compression and shear testing of the polymer parts. The second portion of the research evaluates the impact of the reinforcement materials on the transmission of radio frequency to and from the tag. The last portion of the research looks at how the costs of RFID compare to the …


Surface Engineered Biosensors For The Early Detection Of Cancer, Muhymin Islam Jan 2015

Surface Engineered Biosensors For The Early Detection Of Cancer, Muhymin Islam

Electrical Engineering Dissertations - Archive

Cancer commences in the building block of human body which is cells and in most of the cases remains silent at early stage. Diseases are only expressed at molecular and cellular level at primary stages. Recognition of diseases at this micro and nano level might reduce the mortality rate of cancer significantly. This research work aimed to introduce novel electronic biosensors for for identification of cancer at cellular level. The dissertation study focuses on 1) Label-Free Isolation of Metastatic Tumor Cells Using Filter Based Microfluidic device; 2) Nanotextured Polymer Substrates for Enhanced Cancer Cell Isolation and Cell Growth; 3) Nanotextured …


Forecasting Of Wind, Pv Generation, And Market Price For The Optimal Operations Of The Regional Pev Charging Stations, Piampoom Sarikprueck Jan 2015

Forecasting Of Wind, Pv Generation, And Market Price For The Optimal Operations Of The Regional Pev Charging Stations, Piampoom Sarikprueck

Electrical Engineering Dissertations - Archive

The transition from the conventional spark ignition engine vehicles to the electric vehicular technologies helps reduce greenhouse gas (GHG) emissions as well as improve the energy efficiency in the transportation sector. In the transformation of the electric vehicle, the hybrid electric vehicle (HEV) has evolved into the plug-in electric vehicle (PEV) due to the advancement in battery technologies that extend the electric driving distance of vehicles; however, this trend also creates concern among PEV users about how long or how far they might travel per battery charge. A well-planned charging infrastructure with a fast (level 3) charging station is critical …


Sparse Sampling And Array For Wireless Communications, Qiong Wu Jan 2015

Sparse Sampling And Array For Wireless Communications, Qiong Wu

Electrical Engineering Dissertations - Archive

In recent years, sparse sampling and array, such as coprime sampling, nested sampling, nested array, attract attention for their potential to estimate autocorrelation coefficients with all lags, and to calculate the power spectrum density. But this theoretical merit is based on the premise that the input signals are wide-sense stationary. This dissertation first implements the coprime sampling for non-stationary signal, which still decreases the computational complexity but suffers from high variances due to lack of observations. Then, this algorithm is extended to calculate ambiguity function in the radar system, and several practical guidelines are concluded in order to conduct the …


Arc Flash Hazards Analysis, Zhenyuan Zhang Jan 2015

Arc Flash Hazards Analysis, Zhenyuan Zhang

Electrical Engineering Dissertations - Archive

Annually more than 2000 workers are admitted to hospital burn centers for extensive injuries caused by arc flash accidents. Arc flash incidents occur when unintended electric current flows through air, superheating the air and causes an explosion. Recognizing the significant threat posed by arc flash hazards, IEEE and NFPA have joined forces on an initiative to support research and additional testing to increase the understanding of the arc flash phenomena. Accurately represent all the real applications for arc flash events are very difficult, not only because of their random complex nature, but also because a large number of uncertain variables …


Virtual And Hardware Prototyping Of A Modular Multilevel Inverter For Photovoltaics, Shweta Hardas Jan 2015

Virtual And Hardware Prototyping Of A Modular Multilevel Inverter For Photovoltaics, Shweta Hardas

Electrical Engineering Theses - Archive

This thesis details the idea of virtual and hardware prototyping of a distributed controlled multilevel inverter used as a grid-tie interface for photovoltaic. The system framework consists of multilevel inverters composed of solar panel array connected in series with the inverter module, enabling the use of renewable energy resources. The inverter module is built of buck-boost converter and a cascaded h-bridge inverter, which converts the obtained independent DC voltage source from each of the solar array to AC. With the increasing convenience of using a small photovoltaic grid for residential purposes, this system can be used to facilitate various DC …


Model-Based Design And Analysis Of Automotive Systems Using Time-Triggered Controller Area Networks, Ruoshi Zhang Jan 2015

Model-Based Design And Analysis Of Automotive Systems Using Time-Triggered Controller Area Networks, Ruoshi Zhang

Electrical Engineering Theses - Archive

As the numbers of electrical and electronics (E/E) components vastly increases in modern motor vehicles, vehicle safety risks and recalls due to E/E problems have become issues for both auto manufactures and customers. This thesis describes methods to assist designers to analyze legacy designs incorporating the Time-Triggered Controller Area Network (TTCAN) bus in a post-design phase. We present a case study for the UT-Arlington Formula SAE all-electric race car, which has 18 controller area network (CAN) PIC microcontroller nodes using the TTCAN protocol. The contributions include the general approach to re-using legacy software in MBD processes, the automotive case study …


Is Service-Learning Worth It?: A Mixed-Methods Study Of Faculty’S Service-Learning Experiences, Joan M. Blakey, Shirley Theriot, Mary Cazzell, Melanie L. Sattler Jan 2015

Is Service-Learning Worth It?: A Mixed-Methods Study Of Faculty’S Service-Learning Experiences, Joan M. Blakey, Shirley Theriot, Mary Cazzell, Melanie L. Sattler

Civil Engineering Faculty Publications - Archive

Service-learning benefits students, communities, institutions of higher learning, and faculty. Most studies have focused on the impact of service-learning on students; however, there is a dearth of mixed-methods research examining faculty use of service-learning. Using a two-phase, exploratory, mixed-methods design, the purpose of this study was to understand the factors that influenced 24 faculty fellows’ engagement with service-learning. The qualitative component examined four faculty’s in-depth experiences with service-learning to understand the meaning they assigned to those experiences and to identify key themes that affected engagement. The quantitative phase of the study explored the extent to which 20 additional faculty fellows’ …


Development Of A Simplified Flexible Pavement Design Protocol For New York State Department Of Transportation Based On Aashto Me Pavement Design Guide, Ali Qays Abdullah Jan 2015

Development Of A Simplified Flexible Pavement Design Protocol For New York State Department Of Transportation Based On Aashto Me Pavement Design Guide, Ali Qays Abdullah

Civil Engineering Dissertations - Archive

New York State Department of Transportation (NYSDOT) has used the AASHTO 1993 Design Guide for the design of new flexible pavement structures for more than three decades. The AASHTO 1993 Guide is based on the empirical relationships developed for the data collected in the AASHO Road Test in the early 1960's. A newer pavement design method, called the Mechanistic-Empirical Pavement Design Guide (MEPDG) was developed by the National Cooperative Highway Research Program to provide a more efficient and accurate design method and based on sound engineering principles. The MEPDG models have been incorporated in the AASHTOWare Pavement ME 2.1 software …


Topology Optimization For Thin Walled Structures Utilizing Simp Method By Additive Manufacturing Using Optimized Conditions, Sajith Anantharaman Jan 2015

Topology Optimization For Thin Walled Structures Utilizing Simp Method By Additive Manufacturing Using Optimized Conditions, Sajith Anantharaman

Mechanical and Aerospace Engineering Theses - Archive

The objective of this research is to manufacture topology optimized structure by additive manufacturing. Topology Optimization is a method of structural optimization which gives the optimum material distribution in a design domain. This material distribution is then manufactured by additive manufacturing. Additive manufacturing can manufacture complex shapes quite easily since it works by layer-by-layer. This is an on-going field of research and not many optimization algorithms make use of the advantages of additive manufacturing. Numerous researches are done in the field of optimization which are directed towards Homogenization and Solid Isotropic material with Penalization (SIMP). But most of the methods …


Diffusion And Elastoplastic Analyses Of Polycrystalline Magnesium For Solid State Hydrogen Storage Application, Amey Mathakari Jan 2015

Diffusion And Elastoplastic Analyses Of Polycrystalline Magnesium For Solid State Hydrogen Storage Application, Amey Mathakari

Mechanical and Aerospace Engineering Theses - Archive

Solid state hydrogen storage can be an effective way of storing hydrogen as an energy source for mobile applications. The advantage includes high energy density, low setup cost, safe operation, abundance of metal hydrides, low maintenance, etc. Magnesium is one of the potential metals for the application. However, sluggish desorption kinetics of magnesium requiring relatively high operation temperature has hindered its practical realization. In the present study, an attempt is made to analyze effects of grain boundary on diffusion and diffusion induced stresses in polycrystalline magnesium. Grain boundaries in nanostructured magnesium can undergo severe plastic deformations during the hydrogen insertion …


Simulation And Performance Analysis Of Ejector Nozzle In A Low-Bypass Turbofan Engine Using Npss, Hatim Soeb Rangwala Jan 2015

Simulation And Performance Analysis Of Ejector Nozzle In A Low-Bypass Turbofan Engine Using Npss, Hatim Soeb Rangwala

Mechanical and Aerospace Engineering Theses - Archive

Nozzles for propulsive applications in airbreathing engines have long been studied to augment thrust and reduce the size of the engine. They are critical elements of the engine as they convert the internal energy into kinetic energy, thereby producing thrust. Fixed-geometry nozzles are operated optimally only at a particular set of flight conditions and are not efficient at off-design conditions. To improve off-design performance, variable geometry nozzles can be utilized which require complex mechanisms that ultimately increase weight and susceptibility to failure. Ejector nozzles provide variable geometry capability via aerodynamically varying the effective area ratios of the core and bypass …


Assessing Interlaminar Shear Stress-Strain Curves In Tape Composites Based On The Flat-Plate Torsion Method, Gary Steven Grohman Jan 2015

Assessing Interlaminar Shear Stress-Strain Curves In Tape Composites Based On The Flat-Plate Torsion Method, Gary Steven Grohman

Mechanical and Aerospace Engineering Theses - Archive

Composites are attractive for structural applications in the aerospace industry for their high strength to weight ratio, stiffness, and low density. The development and implementation of composite structures has grown rapidly through the aerospace industry exceeding our ability to characterize the material properties due to costly and time consuming test methods. The ability to fully characterize the nonlinear stress-strain relationship in the 1-3 and 2-3 principal planes up to the point of failure is extremely important for predicting failures in composites. The principal directions for composites are the fiber direction, transverse direction, and the thru thickness direction, commonly referred to …


Heat Removal Analysis Using Ntu Microscopic Theory And Experimental Fluid Testing Of Radaitors, Pumps And Fans For The Thermal Management System Of Formula Sae Electric Racecar, Shahzad Shahrukh Bulsara Jan 2015

Heat Removal Analysis Using Ntu Microscopic Theory And Experimental Fluid Testing Of Radaitors, Pumps And Fans For The Thermal Management System Of Formula Sae Electric Racecar, Shahzad Shahrukh Bulsara

Mechanical and Aerospace Engineering Theses - Archive

Formula SAE at UT Arlington has always been building well engineered race cars, further being one of the top teams in The United States. However, an electric race car being first in the fleet, cooling of electric motors played a vital role. The thermal system being significantly different from combustion cars, consists of a lower heat application. It is always favorable to maintain electronics as close to ambient temperature as compared to its counter hydro-mechanical engines. To attain the objective, a complete thermal & fluid analysis was carried out using the NTU method/ microscopic theory and experimental results associated towards …


Training Algorithm For Radial Basis Function Classifier, Yilong Hao Jan 2015

Training Algorithm For Radial Basis Function Classifier, Yilong Hao

Electrical Engineering Theses - Archive

The computational complexity of kernel machines and their poor performance in the multi-label classification case is a major bottleneck in their success. In this thesis we present a systematic two step batch approach for constructing and training a new multiclass kernel machine (MKM). Unlike other kernel learning algorithms, the proposed paradigm prunes the kernels, and uses Newton’s method to improve the kernel parameters. In each iteration, output weights are found using orthogonal least squares. The proposed hybrid training algorithm is compared with those least square support vector machines(LS-SVM) and support vector machines(SVM). Simulations results on many benchmark and real life …