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 1681 - 1710 of 3180

Full-Text Articles in Engineering

Realistic Interaction With Social Robots Via Facial Expressions And Neck-Eye Coordination, Sumit Kumar Das Jan 2015

Realistic Interaction With Social Robots Via Facial Expressions And Neck-Eye Coordination, Sumit Kumar Das

Electrical Engineering Theses - Archive

In this thesis, we report on research work concerning various aspects of interaction between an android head and its environment. The research aims at building a reusable framework of interaction through facial expressions and vision which can be used for a wide range of humanoid robotic heads. The framework contains specially programmed modules that enable the android head to effectively interact with its environment via facial expressions and neck-eye coordinated motion.The object detection and tracking module enables the android head to detect and track objects and users through coordinated motions of neck and eye. The module has the capability of …

Go to article

Motion Learning And Control For Social Robots In Human-Robot Interaction, Namrata Balakrishnan Jan 2015

Motion Learning And Control For Social Robots In Human-Robot Interaction, Namrata Balakrishnan

Electrical Engineering Theses - Archive

In the domain of social robotics, robots have recently been used in conversational interaction with humans. In this thesis, research was conducted to help create a system for imitation learning. In this system, a trainer trains a robot to be a teacher. The robotic teacher interacts with other humans in order to teach them the task that the robot was trained on. The method of `Teaching by Demonstration' was used, where an ideal motion is performed by a trainer. This ideal motion is learned by the robot and replayed in the subsequent interaction with humans. If the replayed motion is …

Go to article

Channel Estimation And Statistical Analysis Of Indoor Environment Using Ultrawideband Radio Technology, Shruthishree Bangalore Krishnamurthy Jan 2015

Channel Estimation And Statistical Analysis Of Indoor Environment Using Ultrawideband Radio Technology, Shruthishree Bangalore Krishnamurthy

Electrical Engineering Theses - Archive

Ultra-wideband technology finds various applications in radar technology, medical imaging, see-through-wall applications, surveillance and short distance communication applications. All of these applications require that the behavior of the channel be estimated giving a priori information about the various attributes of the channel like path loss, delay spread, channel capacity and so on. These parameters are the key to design an effective communication infrastructure suitable for the needs of the application.In this thesis, the main aim was to model the channel and extract the various parameters related to the channel through data processing methods. In particular, a classroom environment was chosen …

Go to article

Embedded Data Acquisition Platform For Surface Measurements On Wet Concrete, Anuja Raikar Jan 2015

Embedded Data Acquisition Platform For Surface Measurements On Wet Concrete, Anuja Raikar

Electrical Engineering Theses - Archive

The early detection of roughness over newly poured wet concrete allows correction of the surface before concrete is hardened. The smoothness of the wet concrete can be monitored and controlled at an early stage saving additional effort and cost. The goal of this research study is to examine the techniques to detect the roughness over the surface of wet cement concrete. A sliding profiler is one of the techniques which estimates profile of the surface based on the bumps detected on freshly poured concrete. This thesis focuses on the data acquired by the sliding profiler using a different measurement sensor …

Go to article

Improving Fracture Toughness Of Silicon Carbide Based Ceramics By Microstructure Tailoring, Sheikh Fahad Ferdous Jan 2015

Improving Fracture Toughness Of Silicon Carbide Based Ceramics By Microstructure Tailoring, Sheikh Fahad Ferdous

Mechanical and Aerospace Engineering Dissertations - Archive

Ceramic materials are one of the most promising materials for wide variety of technical applications such as automotive, aerospace, medical, and other applications. They have very high strengths and high melting points relative to metals. However, low fracture toughness is one of the main barriers of ceramics prohibiting their wide-spread applications. This is because ceramics are mainly bonded with directional bonds which don’t allow dislocations based deformation. Several attempts have been made to increase the toughness of ceramic materials without sacrificing significantly the other mechanical properties. Here three different types of SiC based ceramics have been computationally (atomistic and up-scaled …

Go to article

Novel Device And Methods For Composite Material Characterization, Michael M. Tadros Jan 2015

Novel Device And Methods For Composite Material Characterization, Michael M. Tadros

Mechanical and Aerospace Engineering Dissertations - Archive

Composite materials have several advantages over metallic materials, with their high specific strength and ability to be elastically tailored to create advantageous structural responses. However, the widespread implementation of composite materials in primary structures is limited by our knowledge of how damage mechanisms interact and spread inside composite parts. To date, characterization has been conducted using one of two methods, surface measurements and subsurface measurements. Surface measurements cannot in general capture the failure of multidirectional composite laminates. Subsurface measurements allow for observations of the internal material structure and damage mechanisms inside the composite which might facilitate greater understanding of the …

Go to article

Computational Analysis Of I.T. Rack Under Vibration Load, Framroz Meheryar Bharucha Jan 2015

Computational Analysis Of I.T. Rack Under Vibration Load, Framroz Meheryar Bharucha

Mechanical and Aerospace Engineering Theses - Archive

Structural failure of a rack due to vibration could result in injury to people, damage to IT equipment, or interruption of services that depend on proper functioning of the IT and networking equipment in the rack. In this topic, a computational study of an IT rack and a group of racks placed adjacent to each other under three vibration load scenarios: transportation, office and earthquake vibration is presented.Each rack can weigh as much as 1600 kg (3500 lb.) when fully populated with IT equipment. Two standards commonly used for testing racks with synthetic seismic loads are the GR-63-CORE Network Equipment …

Go to article

Performance Analysis Of A Helium Cooled Vhtr Powered Brayton Cycle Topping Unit On An Existing Steam Cycle Using Numerical Propulsion System Simulation, Warren Romao Caetano Freitas Jan 2015

Performance Analysis Of A Helium Cooled Vhtr Powered Brayton Cycle Topping Unit On An Existing Steam Cycle Using Numerical Propulsion System Simulation, Warren Romao Caetano Freitas

Mechanical and Aerospace Engineering Theses - Archive

With the decommissioning of ageing coal power plants due to outdated technology and high levels of air pollution, the advantages of overhauling existing infrastructure is twofold. First, by providing an alternate, sustainable fuel source, like nuclear power, the problem of air pollution can be brought to check. Second, utilizing existing steam plant infrastructure reduces initial investment costs and allows investors to keep the existing steam plant running until the new infrastructure is ready to go online.The focus of this research is to design and analyze the topping cycle required to support an existing 300 MW power plant based on the …

Go to article

Quantifying Air Flow Rate Through A Server In An Operational Data Center And Assessing The Impact Of Using Theoretical Fan Curve, Neha Shigrekar Jan 2015

Quantifying Air Flow Rate Through A Server In An Operational Data Center And Assessing The Impact Of Using Theoretical Fan Curve, Neha Shigrekar

Mechanical and Aerospace Engineering Theses - Archive

Cooling is one of the major cost factors in data centres that accounts for 37% of the total data centre electricity consumption. Demands on cooling systems have increased substantially in recent years, due to increasing server densities. To avoid the overheating of servers, cooling aisles are over provisioned, but little attention is paid to the actual scenario at the server level. Cooling requirements of the servers is calculated on the basis of fan manufacturer’s published data for the air flow capacity of the server fan and system impedance data obtained from the server designer put together. Thus, the air flow …

Go to article

Optimal Operation Of Microgrid Under A Stochastic Environment, Zhaohao Ding Jan 2015

Optimal Operation Of Microgrid Under A Stochastic Environment, Zhaohao Ding

Electrical Engineering Dissertations - Archive

With its technological and regulatory innovation of scale and structure, microgrids have been developed all over the world as a mean to address the high penetration level of renewable generation, reduce the greenhouse gas emission, and provide economical solutions for the currently non-electrified area. The operation of microgrid requires resource planning for those fossil-fuel based generators, energy storage systems, and demand resources if demand side management is implemented. Due to the stochastic nature of renewable energy resources, load behaviors and market prices, enormous uncertainties are involved in the microgrid operation and scheduling problems for both short-term and longer term. These …

Go to article

Employing Online Data For Dynamic Equivalent Model Parameter Identification Of Large Scale Wind Farm, Xueyang Cheng Jan 2015

Employing Online Data For Dynamic Equivalent Model Parameter Identification Of Large Scale Wind Farm, Xueyang Cheng

Electrical Engineering Dissertations - Archive

As one of the major renewable energy sources, wind power has experienced a fast growth in recent years. The installed capacity of wind farms has increased dramatically. Similar to other generator facilities, their impacts on power system transient stability and power quality should be carefully studied when large scale wind farms are integrated into the power grid. Therefore, it is necessary to establish an accurate dynamic model of large scale wind farm for researches and engineers. A large scale wind farm may have hundreds of WTGs and the structure of WTGs is very complicated and manufacture dependent. If each machine …

Go to article

Electrostatic And Piezoelectric Micro Energy Harvesters For Environmental Vibrational Energy Scavenging, Yi Li Jan 2015

Electrostatic And Piezoelectric Micro Energy Harvesters For Environmental Vibrational Energy Scavenging, Yi Li

Electrical Engineering Dissertations - Archive

Nowadays wireless sensors are widely used in all kinds of fields such as biomedical, commercial and military. Micro energy harvesters converting the wasteful energy from environment into electricity enable the possibility of self-powered wireless sensor systems. This dissertation aims to develop micro energy harvesters to harness wasted mechanical vibrational energy. An electrostatic micro energy scavenger was designed to incorporate MEMS comb-drive in-plane overlap as well as in-plane gap closing topologies into one hybrid structure. The device geometry and dimensions were optimized to maximize the energy harvesting efficiency. UV-LIGA process combined with nickel electroplating was utilized to fabricate the devices. A …

Go to article

A Microwave Backscattering Model For Precipitation, Seda Ermis Jan 2015

A Microwave Backscattering Model For Precipitation, Seda Ermis

Electrical Engineering Dissertations - Archive

A geophysical microwave backscattering model for space borne and ground-based remote sensing of precipitation is developed and used to analyze backscattering measurements from rain and snow type precipitation. Vector Radiative Transfer (VRT) equations for a multilayered inhomogeneous medium are applied to the precipitation region for calculation of backscattered intensity. Numerical solution of the VRT equation for multiple layers is provided by the matrix doubling method to take into account close range interactions between particles. In previous studies, the VRT model was used to calculate backscattering from a rain column on a sea surface [41]. In the model, Mie scattering theory …

Go to article

Autonomous Robotic Landmine Detection, Mapping And Avoidance, Sandesh Gowda Jan 2015

Autonomous Robotic Landmine Detection, Mapping And Avoidance, Sandesh Gowda

Electrical Engineering Theses - Archive

The objective of this thesis is to develop detection algorithm to can solve socially challenging issue of Landmine mapping & removal. Landmines which used to be a safety measure during wars, play a dangerous role in civilian life, in and around the post combat regions with approximately 78 countries observing an estimate of 42 human lives killed every day. To prevent the number of casualties and manual mine clearance, mobile robots can be used for detection & mapping of the mine field region.Mapping, detection and avoidance are the primary challenges faced on a landmine removal. In this thesis, mine center …

Go to article

Hemodynamic Responses To Thermal Stimulation In The Prefrontal Cortex Of The Brain Measured By Fnirs, Koumudi Chari Jan 2015

Hemodynamic Responses To Thermal Stimulation In The Prefrontal Cortex Of The Brain Measured By Fnirs, Koumudi Chari

Bioengineering Theses - Archive

Although FMRI has marked its importance in the neurological research by understanding the brain activities, FNIRS has also set a new standard in the brain imaging study research with non-invasive and easy to use technology. FNIRS is a portable, inexpensive optical imaging method that measures the changes in the oxygenated and de-oxygenated hemoglobin of the brain that results from the neurological activity. In this study, FNIRS has been used to study the pain processing in humans by measuring the pre-frontal cortex area of the brain. Eight (n=8) healthy subjects were induced with pain using a thermal stimulator device with temperatures …

Go to article

An Investigation Of The Covariations Between Variations In Exhaled Carbon Dioxide And Cerebral Blood Flow Levels During Apnea, Varun Ajay Kanal Jan 2015

An Investigation Of The Covariations Between Variations In Exhaled Carbon Dioxide And Cerebral Blood Flow Levels During Apnea, Varun Ajay Kanal

Bioengineering Theses - Archive

Sleep apnea is a breathing disorder characterized by repetitive reduction or cessation of breathing during sleep. It is estimated that that around 17% of adults suffer from mild to severe sleep disordered breathing. The aim of this study was to investigate the level of correlation between variations in exhaled CO2 and cerebral blood flow (CBF) during apnea. It is difficult to measure the CBF during sleep. This relationship was found in an effort to substitute the measurement of the changes in CBF with the changes in the CO2. The relationship between these two physiological parameters was first studied in healthy …

Go to article

Two-Stage Stochastic Programming In Adaptive Interdisciplinary Pain Management, Na Wang Jan 2015

Two-Stage Stochastic Programming In Adaptive Interdisciplinary Pain Management, Na Wang

Industrial, Manufacturing, and Systems Engineering Dissertations - Archive

Chronic pain is a global health problem. About 100 million adult Americans suffering from chronic pain, which costs $560 - $635 billion per year. The Eugene McDermott Center for Pain Management at the University of Texas Southwestern Medical Center at Dallas conducted a two-stage pain management program for patients who suffer from chronic pain. Data information such as patient’s parameter, past treatment, pain outcome at different evaluation point and so on has been collected by the McDermott Center. The University of Texas at Arlington is collaborating with the McDermott Center to find optimal treatment strategies for individual patients.A treatment strategy …

Go to article

High-Dimensional Adaptive Dynamic Programming With Mixed Integer Linear Programming, Zirun Zhang Jan 2015

High-Dimensional Adaptive Dynamic Programming With Mixed Integer Linear Programming, Zirun Zhang

Industrial, Manufacturing, and Systems Engineering Dissertations - Archive

Dynamic programming (DP, Bellman 1957) is a classic mathematical programming approach to solve multistage decision problems. The “Bellman equation” uses a recursive concept that includes both the current contribution and future contribution in the objective function of an optimization. The method has potential to represent dynamic decision-making systems, but an exact DP solution algorithm is limited to small problems with restrictions, such as problems with linear transitions and problems without uncertainty. Approximate dynamic programming (ADP) is a modern branch of DP that seeks to achieve numerical solutions via approximation. It is can be applied to real-world DP problems, but there …

Go to article

Performance Characteristics Of Single Effect Lithium Bromide/ Water Absorption Chiller For Small Data Centers, Abhishek Arun Babu Mysore Jan 2015

Performance Characteristics Of Single Effect Lithium Bromide/ Water Absorption Chiller For Small Data Centers, Abhishek Arun Babu Mysore

Mechanical and Aerospace Engineering Theses - Archive

A medium data center consists of servers performing operations such as file sharing, collaboration and email. There are a large number of small and medium data centers across the world which consume more energy and are less efficient when compared to large data center facilities of companies such as GOOGLE, APPLE and FACEBOOK. Such companies are making their data center facilities more environmental friendly by employing renewable energy solutions such as wind and solar to power the data center or in data center cooling. This not only reduces the carbon footprint significantly but also decreases the costs incurred over a …

Go to article

Chip Package Interaction Study To Analyze The Mechanical Integrity Of A 3-D Tsv Package, Pavan Rajmane Jan 2015

Chip Package Interaction Study To Analyze The Mechanical Integrity Of A 3-D Tsv Package, Pavan Rajmane

Mechanical and Aerospace Engineering Theses - Archive

The convergence and miniaturization of computing and communications dictates building up rather than out. As planar device miniaturization continues to its ultimate limits, the complexity of circuit interconnections for 2-D devices becomes a limitation for performance and drives up power dissipation [1]. As the consumers demand more functions on their hand-held electronic devices, the need for more devices such as memory, CPU and GPU in hand-held type footprints is increasing. Chip-stacking (3-D) is emerging as a powerful tool that satiates such IC package requirements. A 3-D FPGA would overcome the interconnect limitations, resulting in greater silicon efficiency per function (number …

Go to article

Experimental Study Of Quaternary Nitrate/Nitrite Molten Salt As Advanced Heat Transfer Fluid And Energy Storage Material In Concentrated Solar Power Plant, Sumeet Changla Jan 2015

Experimental Study Of Quaternary Nitrate/Nitrite Molten Salt As Advanced Heat Transfer Fluid And Energy Storage Material In Concentrated Solar Power Plant, Sumeet Changla

Mechanical and Aerospace Engineering Theses - Archive

Solar energy is used to produce electricity by two methods namely photovoltaic and concentrated solar power plant systems. Concentrated Solar power plants hold a distinct advantage over photovoltaic, which is that of energy storage. Energy can be stored in thermal energy storage system during day time and can be used to dispatch energy during peak demand and during raining or cloudy days to produce electricity. All concentrated solar power plants in operation use sensible heat storage method to store energy. Sensible heat storage system have been used in industry owing to ease of dispatch ability. Currently a binary mixture of …

Go to article

Impact Of Viscoelastic Material Characterization Of Pcb's On Thermomechanical Properties Of Qfn Thick Package Under Thermal Cycling, Karthik Rajashekar Jan 2015

Impact Of Viscoelastic Material Characterization Of Pcb's On Thermomechanical Properties Of Qfn Thick Package Under Thermal Cycling, Karthik Rajashekar

Mechanical and Aerospace Engineering Theses - Archive

The QFN component package is a quad flat pack (QFP) with “no-leads”, where the electrical contact to the printed circuit board (PCB) is made through soldering of the lands underneath the package body rather than the traditional leads formed along the perimeter. The popularity of this device package style is primarily due to the superior electrical and thermal performance demonstrated. It is one of the most cutting-edge technologies emerged in the market, exhibiting high performance with unparalleled cost effectiveness. But using thick PCBs (>3mm) is detrimental to the package reliability. The motivation of this work is to understand and …

Go to article

Liquid Cooling Of A High-Power Multi-Chip Module Using A Sectioned Cold Plate, Ananthavijayan Sridhar Jan 2015

Liquid Cooling Of A High-Power Multi-Chip Module Using A Sectioned Cold Plate, Ananthavijayan Sridhar

Mechanical and Aerospace Engineering Theses - Archive

With the advancement in micro-fabrication techniques and high performance chips, the heat flux generated through these electronics is reaching a point where air-cooling of these devices is not efficient enough. By definition, Multi-Chip Modules (MCMs) are specialized electronic packages where multiple Integrated-Circuits (ICs) and semiconductor dies are unified onto a single substrate. Increasing advancements in ICs enable MCMs as alternate packaging finding its application in high power electronics like power generation and cooling, medical devices, lasers and, military electronics etc. Hence, liquid cooling techniques are explored as possible solutions. In this study, a high power MCM is considered and, its …

Go to article

Study Of The Effect Of Ion Concentration, Ph, And Surface Charge On Single-Particle Placement, Kunhua Yu Jan 2015

Study Of The Effect Of Ion Concentration, Ph, And Surface Charge On Single-Particle Placement, Kunhua Yu

Material Science and Engineering Theses - Archive

Supervising Professor: Seong Jin Koh Single particle placement (SPP) in which nanoparticles are placed on exact substrate positions on a single particle level has drawn a lot of attention as it can be used as an effective tool for bottom-up fabrications of nanoscale systems. In SPP, single nanoparticles are electrically guided toward substrate target positions through electrostatic funneling mechanism and once a single nanoparticle is placed on a target position it prevents the other nanoparticles from approaching toward the substrate, leading to placement of exactly one nanoparticle on each target position. This thesis investigates the role of three key parameters …

Go to article

Effect Of Termite Gut Microbe Tav5 On Methane Production From Municipal Solid Waste Degradation, Hoda Rahimi Jan 2015

Effect Of Termite Gut Microbe Tav5 On Methane Production From Municipal Solid Waste Degradation, Hoda Rahimi

Civil Engineering Theses - Archive

Methane from anaerobic processes is being increasingly utilized as an alternative energy source in developed countries, via large projects that extract methane from landfills or wastewater treatment plants. Anaerobic degradation of organic material (biomass) involves decomposition by bacteria under humid conditions without any oxygen. Organic carbon deposited in landfills is converted by microbes to carbon dioxide (CO2) and methane (CH4). If the methane is not captured, it contributes to climate change (25 times more effectively than CO2 on a per-mass basis). If the methane is captured, it can be used as a renewable energy resource. Lignocellulose comprises a significant portion …

Go to article

A New Technique For The Estimation Of The Elastic Moduli Of Pavement Layers From Light Weight Deflectometer Data, Nickey Akbariyeh Jan 2015

A New Technique For The Estimation Of The Elastic Moduli Of Pavement Layers From Light Weight Deflectometer Data, Nickey Akbariyeh

Civil Engineering Theses - Archive

This study developed a method to estimate the elastic moduli of a flexible pavement system from Light Weight Deflectometer deflection data. The forward method (simple equations) can be easily programmed into the data acquisition device of the Light Weight Deflectometers. The equations can be of a primary assistance in the evaluation of the flexible pavement structures. The method is simple and it eliminates the need for the backcalculation procedure after the LWD test. The pavement systems considered in this study are composed of 2 to 4 inches of the asphalt concrete wearing layer and 4 to 8 inches of compacted …

Go to article

Potential Applicability Of Stress Wave Velocity Method On Pavement Base Materials As A Non-Destructive Testing Technique, Masrur Mahedi Jan 2015

Potential Applicability Of Stress Wave Velocity Method On Pavement Base Materials As A Non-Destructive Testing Technique, Masrur Mahedi

Civil Engineering Theses - Archive

Aggregates derived from natural sources have been used traditionally as the pavement base materials. But in recent times, the extraction of these natural aggregates has be-come more labor intensive and costly due to resource depletion and environmental concerns. Thus, the uses of recycled aggregates as the supplementary of natural aggregates are increasing considerably in pavement construction. Use of recycled aggregates such as recycled crushed concrete (RCA) and recycled asphalt pavement (RAP) reduces the rate of natural resource depletion, construction debris and cost. Although recycled aggregates could be used as a viable alternative of conventional base materials, strength characteristics and product …

Go to article

Fatigue Life Assessment Of A Critical Field Welded Connection On A Temporary Railway Bridge Span, Curtis Heinsen Jan 2015

Fatigue Life Assessment Of A Critical Field Welded Connection On A Temporary Railway Bridge Span, Curtis Heinsen

Civil Engineering Theses - Archive

There is a need in the railway industry for a flexible solution to the problem of service interruptions due to impacts on railway bridges from highway and other vehicle traffic. One such solution is the placement of a temporary span that can be used on multiple substructure types and configurations and can be quickly assembled from a kit of available parts. In order to minimize the erection time and maximize the span flexibility such a span could utilize welded connections in place of bolted connections throughout the structure. These connections would be vulnerable to fatigue failure which has been shown …

Go to article

Factors Influencing The Microbial Calcium Carbonate Precipitation Performance In Sands, Naga Venkata Prasanna Kumar Velpuri Jan 2015

Factors Influencing The Microbial Calcium Carbonate Precipitation Performance In Sands, Naga Venkata Prasanna Kumar Velpuri

Civil Engineering Theses - Archive

Microbial induced calcium carbonate precipitation is relatively a new ground improvement technique for geotechnical engineers. This technique uses non-pathogenic organisms that are found naturally in soil environment to cement sand particles together at their contacts. This thesis describes the influence of various factors on cementation of MICP-treated soil catalyzed by bacteria and urease from an experimental study. Some of these factors include number of nutrient cycles, concentration of calcium chloride solutions, number of injections and particle size. Finally the objective of my research is to have a better understanding about the effects of various parameters on the biological cementation. Ottawa …

Go to article

Testing, Analysis And Classification Of No-Dig Manhole Rehabilitation Materials, Alimohammad Entezarmahdi Jan 2015

Testing, Analysis And Classification Of No-Dig Manhole Rehabilitation Materials, Alimohammad Entezarmahdi

Civil Engineering Theses - Archive

Gravity flow wastewater collection systems are comprised of sewer pipes and manholes. Failure of a manhole may have catastrophic consequences such as developing a sinkhole in the street and roadway, and at a minimum, wastewater flow will be blocked and stream of the manhole will backup causing a sanitary sewer overflow (SSO). Improving structural conditions of a manhole is critical to minimize these types of failures. This thesis considers the impact of several lining materials including cement mortar, epoxy, polyurethane, cured-in-place composites, and a multi- layer structure material on increasing the structural capabilities of deteriorated manholes. The tasks included in …

Go to article

First Prev Next Last