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Articles 1201 - 1230 of 4566

Full-Text Articles in Engineering

Method For Real-Time Signal Selection For Passive Coherent Location Systems, Nicholas Johnson Jan 2017

Method For Real-Time Signal Selection For Passive Coherent Location Systems, Nicholas Johnson

Electronic Theses and Dissertations

Passive coherent location (PCL) systems use signals of opportunity to perform traditional radar detection, targeting, and tracking functions. Traditionally these signals include FM radio, digital TV, GSM, and GPS because of their availability in most urban environments. A benefit of having an abundance of signals is the ability to choose which of those best meet the desired system intentions. For example, one may want to choose a digital TV signal over an FM radio signal due to its range resolution characteristics. This work presents a novel algorithm for characterizing commercial signals for use in a PCL system. By analyzing each …

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Advanced Control Techniques For Efficiency And Power Density Improvement Of A Three-Phase Microinverter, Seyed Milad Tayebi Jan 2017

Advanced Control Techniques For Efficiency And Power Density Improvement Of A Three-Phase Microinverter, Seyed Milad Tayebi

Electronic Theses and Dissertations

Inverters are widely used in photovoltaic (PV) based power generation systems. Most of these systems have been based on medium to high power string inverters. Microinverters are gaining popularity over their string inverter counterparts in PV based power generation systems due to maximized energy harvesting, high system reliability, modularity, and simple installation. They can be deployed on commercial buildings, residential rooftops, electric poles, etc and have a huge potential market. Emerging trend in power electronics is to increase power density and efficiency while reducing cost. A powerful tool to achieve these objectives is the development of an advanced control system …

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Harnessing Spatial Intensity Fluctuations For Optical Imaging And Sensing, Milad Akhlaghi Bouzan Jan 2017

Harnessing Spatial Intensity Fluctuations For Optical Imaging And Sensing, Milad Akhlaghi Bouzan

Electronic Theses and Dissertations

Properties of light such as amplitude and phase, temporal and spatial coherence, polarization, etc. are abundantly used for sensing and imaging. Regardless of the passive or active nature of the sensing method, optical intensity fluctuations are always present! While these fluctuations are usually regarded as noise, there are situations where one can harness the intensity fluctuations to enhance certain attributes of the sensing procedure. In this thesis, we developed different sensing methodologies that use statistical properties of optical fluctuations for gauging specific information. We examine this concept in the context of three different aspects of computational optical imaging and sensing. …

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Linking Climate Change And Socio-Economic Impact For Long-Term Urban Growth In Three Mega-Cities, Qi Lu Jan 2017

Linking Climate Change And Socio-Economic Impact For Long-Term Urban Growth In Three Mega-Cities, Qi Lu

Electronic Theses and Dissertations

Urbanization has become a global trend under the impact of population growth, socio-economic development, and globalization. However, the interactions between climate change and urban growth in the context of economic geography are unclear due to missing links in between the recent planning megacities. This study aims to conduct a multi-temporal change analysis of land use and land cover in New York City, City of London, and Beijing using a cellular automata-based Markov chain model collaborating with fuzzy set theory and multi-criteria evaluation to predict the city's future land use changes for 2030 and 2050 under the background of climate change. …

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Biological Nutrient Removal (Bnr) Process Optimization And Recovery Of Embedded Energy Using Biodiesel By-Product, Sultan Salamah Jan 2017

Biological Nutrient Removal (Bnr) Process Optimization And Recovery Of Embedded Energy Using Biodiesel By-Product, Sultan Salamah

Electronic Theses and Dissertations

Enhanced biological phosphorus removal (EBPR) as well as biological nitrogen removal require a carbon source to be carried out. Volatile fatty acid (VFAs) (mainly acetic and propionic acids) are the major driving force for EBPR. Many domestic wastewaters have an insufficient amount of VFAs. However, carbon sources such as acetic and propionic acids can be produced using primary solids fermentation process. Due to the cost of VFA production, an external carbon source can be added to the biological nutrient removal (BNR) system that can be fermented to provide the desired VFAs. Glycerol (biodiesel by-product) offers a solution to reduce carbon …

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Investigating The Impact Of Levels Of Experience On Workload During Nuclear Power Plant Operations, Jonathan Harris Jan 2017

Investigating The Impact Of Levels Of Experience On Workload During Nuclear Power Plant Operations, Jonathan Harris

Electronic Theses and Dissertations

The human-machine interface (HMI) of a Nuclear Power Plant (NPP) Main Control Room (MCR) is complex. Understanding HMI factors that influence Reactor Operator (RO) performance and workload when controlling an NPP is important. The Nuclear Regulatory Commission (NRC) began a program of research known as the Human Performance Test Facility (HPTF) with the goal of collecting human performance data to better understand cognitive and physical elements that support safe control room operation. The HPTF team developed an experimental methodology to evaluate workload using perceived ratings, performance measures, and physiological correlates. This methodology focuses on tasks commonly performed during operations in …

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Annual Water Balance Model Based On Generalized Proportionality Relationship And Its Applications, Yin Tang Jan 2017

Annual Water Balance Model Based On Generalized Proportionality Relationship And Its Applications, Yin Tang

Electronic Theses and Dissertations

The main goal of this dissertation research is to derive a type of conceptual models for annual water balance at the watershed scale. The proportionality relationship from the Soil Conservation Service Curve Number method was generalized to annual scale for deriving annual water balance model. As a result, a one-parameter Budyko equation was derived based on one-stage partitioning; and a four-parameter Budyko equation was derived based on two-stage partitioning. The derived equations balance model parsimony and representation of dominant hydrologic processes, and provide a new framework to disentangle the roles of climate variability, vegetation, soil and topography on long-term water …

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Application Of Multiaxial Cyclic Loading For Constitutive Model And Parameter Determination Of Steels, Bassem Felemban Jan 2017

Application Of Multiaxial Cyclic Loading For Constitutive Model And Parameter Determination Of Steels, Bassem Felemban

Electronic Theses and Dissertations

For many candidate materials, constitutive models and their parameters are identified using uniaxial test data. Real components, however, generally operate in a multi-axial loading environments. Consequently, constitutive models deployed by uniaxial conditions may carry over to service conditions with inherit limitations. Research is proposed to determine the constitutive model constants for the creep and plasticity responses of a material via multi-axial fatigue testing which may contain ratcheting. It is conjectured that directly regressing data under conditions that favor those of actual service use will lead to more accurate modeling under these conditions, as well as a reduced consumption of model …

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Improving Safety Under Reduced Visibility Based On Multiple Countermeasures And Approaches Including Connected Vehicles, Yina Wu Jan 2017

Improving Safety Under Reduced Visibility Based On Multiple Countermeasures And Approaches Including Connected Vehicles, Yina Wu

Electronic Theses and Dissertations

The effect of low visibility on both crash occurrence and severity is a major concern in the traffic safety field. Different approaches were utilized in this research to analyze the effects of fog on traffic safety and evaluate the effectiveness of different fog countermeasures. First, a "Crash Risk Increase Indicator (CRII)" was proposed to explore the differences of crash risk between fog and clear conditions. A binary logistic regression model was applied to link the increase of crash risk with traffic flow characteristics. Second, a new algorithm was proposed to evaluate the rear-end crash risk under fog conditions. Logistic and …

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Redox-Active Solid State Materials And Its Biomedical And Biosensing Applications, Ankur Gupta Jan 2017

Redox-Active Solid State Materials And Its Biomedical And Biosensing Applications, Ankur Gupta

Electronic Theses and Dissertations

Reactive oxygen species (ROS) are byproducts of physiological processes in human body, and strengthened production of ROS is known to cause acute conditions such as inflammation, aging, Alzheimer's disease, melanoma and ovarian cancer, fibrosis and multiple sclerosis. Therefore, early detection of ROS at nanomolar concentration (at cellular level) and developing more potent antioxidants is essential for regular health monitoring. As an example, ROS are also responsible for inflammation reactions at orthopedic implants-tissue interface triggered by wear debris. Inflammation induced by ROS results in revision surgery. Coatings of redox-active materials exhibiting antioxidant properties on implants have potential to mitigate the inflammation …

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Characterization Of Mechanical Properties In Nanoparticle Reinforced Hybrid Carbon Fiber Composites Using Photoluminescence Piezospectroscopy, Sanjida Jahan Jan 2017

Characterization Of Mechanical Properties In Nanoparticle Reinforced Hybrid Carbon Fiber Composites Using Photoluminescence Piezospectroscopy, Sanjida Jahan

Electronic Theses and Dissertations

Carbon fiber composites have become popular in aerospace structures and applications due to their light weight, high strength, and high performance. Hybrid carbon fiber reinforced polymer (HCFRP) composites with alumina nanoparticles reinforcement display improved material properties such as fracture toughness, resistance to crack propagation and improved fatigue life. However, homogeneous dispersion of nanoscale materials in the matrix is important for even distribution of the improved properties. Implementing silane coupling agents (SCAs) improves dispersion by acting as a bridge between organic and inorganic materials, which increases interfacial strength and decreases sedimentation by bonding the particulate filler to the fiber reinforcement. This …

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Towards High-Efficiency Data Management In The Next-Generation Persistent Memory System, Xunchao Chen Jan 2017

Towards High-Efficiency Data Management In The Next-Generation Persistent Memory System, Xunchao Chen

Electronic Theses and Dissertations

For the sake of higher cell density while achieving near-zero standby power, recent research progress in Magnetic Tunneling Junction (MTJ) devices has leveraged Multi-Level Cell (MLC) configurations of Spin-Transfer Torque Random Access Memory (STT-RAM). However, in order to mitigate the write disturbance in an MLC strategy, data stored in the soft bit must be restored back immediately after the hard bit switching is completed. Furthermore, as the result of MTJ feature size scaling, the soft bit can be expected to become disturbed by the read sensing current, thus requiring an immediate restore operation to ensure the data reliability. In this …

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Design Of A Framework For Sharing And Generating Combat Damage Assessment(Cda) Of A Hla/Rti Federation, Hongseon Park Jan 2017

Design Of A Framework For Sharing And Generating Combat Damage Assessment(Cda) Of A Hla/Rti Federation, Hongseon Park

Electronic Theses and Dissertations

In this paper, a new framework for sharing Combat Damage Assessment(CDA) is proposed to find out the differences of each CDA system between military combat units belonging to their own federate in a HLA/RTI federation. When there are engagements in a battle among combat units belonging to their own federate in the HLA/RTI federation, each result of damage assessments is very different. This affects the HLA/RTI federation’s confidence and needed to be overcome because it is also one of the major issues to generate reliable engagement data. Also, a RTI can generate only qualitative data about combat damage while quantitative …

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Developing Warrants For Designing Continuous Flow Intersection And Diverging Diamond Interchange, Meshal Almoshaogeh Jan 2017

Developing Warrants For Designing Continuous Flow Intersection And Diverging Diamond Interchange, Meshal Almoshaogeh

Electronic Theses and Dissertations

The main goal of this dissertation is to have better understanding of design and operation of the Continuous Flow Intersection (CFI) and Diverging Diamond Interchange (DDI) - as well as numerous factors that affect signalized intersection and interchange performance due to increased left-turn demand. The dissertation attempts to assess the need and justification to redesign intersections and interchanges to improve their efficiency. And to that end, an extensive literature review of existing studies was done with the prime aim of perceiving the principles of these innovative designs and determining the methodology to-be-followed, in order to reach the study's core. Accordingly, …

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Design, Simulation And Characterization Of Novel Electrostatic Discharge Protection Devices And Circuits In Advanced Silicon Technologies, Wei Liang Jan 2017

Design, Simulation And Characterization Of Novel Electrostatic Discharge Protection Devices And Circuits In Advanced Silicon Technologies, Wei Liang

Electronic Theses and Dissertations

Electrostatic Discharge (ESD) has been one of the major reliability concerns in the advanced silicon technologies and it becomes more important with technology scaling. It has been reported that more than 35% of the failures in integrated circuits (ICs) are ESD induced. ESD event is a phenomenon that a finite amount of charges transfer between two objects with different potential in a quite short time. Such event contains a large energy and the ICs without proper ESD protection could be destroyed easily, so ESD protection solutions are essential to semiconductor industry. ESD protection design consists of on-chip and off-chip ESD …

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Learning Kernel-Based Approximate Isometries, Mahlagha Sedghi Jan 2017

Learning Kernel-Based Approximate Isometries, Mahlagha Sedghi

Electronic Theses and Dissertations

The increasing availability of public datasets offers an inexperienced opportunity to conduct data-driven studies. Metric Multi-Dimensional Scaling aims to find a low-dimensional embedding of the data, preserving the pairwise dissimilarities amongst the data points in the original space. Along with the visualizability, this dimensionality reduction plays a pivotal role in analyzing and disclosing the hidden structures in the data. This work introduces Sparse Kernel-based Least Squares Multi-Dimensional Scaling approach for exploratory data analysis and, when desirable, data visualization. We assume our embedding map belongs to a Reproducing Kernel Hilbert Space of vector-valued functions which allows for embeddings of previously unseen …

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End To End Brain Fiber Orientation Estimation Using Deep Learning, Nandakishore Puttashamachar Jan 2017

End To End Brain Fiber Orientation Estimation Using Deep Learning, Nandakishore Puttashamachar

Electronic Theses and Dissertations

In this work, we explore the various Brain Neuron tracking techniques, one of the most significant applications of Diffusion Tensor Imaging. Tractography is a non-invasive method to analyze underlying tissue micro-structure. Understanding the structure and organization of the tissues facilitates a diagnosis method to identify any aberrations which can occur within tissues due to loss of cell functionalities, provides acute information on the occurrences of brain ischemia or stroke, the mutation of certain neurological diseases such as Alzheimer, multiple sclerosis and so on. Under all these circumstances, accurate localization of the aberrations in efficient manner can help save a life. …

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Developing An Insider Threat Experimental Environment, Eric Ortiz Jan 2017

Developing An Insider Threat Experimental Environment, Eric Ortiz

Electronic Theses and Dissertations

Simulated, 3D gaming environments have been used for a wide-range of applications including training, entertainment, and experimentation in an assortment of domains for some time. This can be attributed to their unique ability to emulate multifaceted situations that may be difficult to control, while affording participants the opportunity to operate in a relatively safe environment. In cybersecurity research, investigation of insider threat behavior is an endeavor that has received little attention in terms of available environments and resources for experimental manipulation. This research effort aimed to close this gap. A simulated, 3D gaming environment and accompanying scenarios were developed for …

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Heat Transfer, Friction, And Turbulent Analysis On Single Ribbed-Wall Square Channel, Christopher Vergos Jan 2017

Heat Transfer, Friction, And Turbulent Analysis On Single Ribbed-Wall Square Channel, Christopher Vergos

Electronic Theses and Dissertations

An experimental investigation of heat transfer and friction behavior for a fully developed flow in a non-rotating square channel was conducted under a wide range of Reynolds numbers from 6,000 to 180,000. The rig used in this study was a single ribbed wall variant of Ahmed et al.'s [ 1 ] rig from which results of this rig were compared. Ahmed et al.'s rig was a replica of Han et al.'s square channel [ 2 ] used to validate their work, and expand the Reynolds number range for both heat transfer and friction data. The test section was 22 hydraulic …

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Ultra-Efficient Cascaded Buck-Boost Converter, Anirudh Ashok Pise Jan 2017

Ultra-Efficient Cascaded Buck-Boost Converter, Anirudh Ashok Pise

Electronic Theses and Dissertations

This thesis presents various techniques to achieve ultra-high-efficiency for Cascaded-Buck-Boost converter. A rigorous loss model with component non linearity is developed and validated experimentally. An adaptive-switching-frequency control is discussed to optimize weighted efficiency. Some soft-switching techniques are discussed. A low-profile planar-nanocrystalline inductor is developed and various design aspects of core and copper design are discussed. Finite-element-method is used to examine and visualize the inductor design. By implementing the above, a peak efficiency of over 99.2 % is achieved with a power density of 6 kW/L and a maximum profile height of 7 mm is reported. This converter finds many applications …

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Investigation Of Heat Transfer Enhancement Within A Concentric Annulus, Alexander Hanhold Jan 2017

Investigation Of Heat Transfer Enhancement Within A Concentric Annulus, Alexander Hanhold

Electronic Theses and Dissertations

Effective heat exchange is key for many energy applications including heat exchangers, heat extraction from heat source, and heat rejection to ambient thermal sink. This study focuses on the investigation for a specific heat exchange configuration, namely heat removal within a concentric annular passage using helical turbulators and jet impingement. Numerical testing was used to see how the different geometric parameters affect the heat transfer and pressure drop within the annulus by using helicoil turbulators. A vast range of designs were studied by changing the turbulator shape, pitch, and blockage ratio while maintaining a constant Reynolds number of 25,000. CFD …

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Reducing Sulfuric Acid Pretreatment In A Nanofiltration Process Treating Surficial Groundwater, Carlyn Higgins Jan 2017

Reducing Sulfuric Acid Pretreatment In A Nanofiltration Process Treating Surficial Groundwater, Carlyn Higgins

Electronic Theses and Dissertations

Nanofiltration (NF) is a pressure driven membrane process employed in drinking water treatment that requires pretreatment for reliable operation. The objective of this research was to determine if NF membranes can proficiently operate with a decreased or eliminated dose of sulfuric acid pretreatment. When used as pretreatment, sulfuric acid prevents calcium carbonate scaling on NF membranes, yet is costly, hazardous, and imparts high sulfate concentrations to NF feed and concentrate streams. To conduct this research, a 0.324 million gallon per day (MGD) NF pilot plant was operated for 3,855 run-hours at a flux rate of 15 gallons per square foot-day. …

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Development Of An Adaptive Restoration Tool For A Self-Healing Smart Grid, Amir Golshani Jan 2017

Development Of An Adaptive Restoration Tool For A Self-Healing Smart Grid, Amir Golshani

Electronic Theses and Dissertations

Large power outages become more commonplace due to the increase in both frequency and strength of natural disasters and cyber-attacks. The outages and blackouts cost American industries and business billions of dollars and jeopardize the lives of hospital patients. The losses can be greatly reduced with a fast, reliable and flexible restoration tool. Fast recovery and successfully adapting to extreme events are critical to build a resilient, and ultimately self-healing power grid. This dissertation is aimed to tackle the challenging task of developing an adaptive restoration decision support system (RDSS). The RDSS determines restoration actions both in planning and real-time …

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Polyurethane Fiber Reinforced Polymer Strengthening Of Shear Deficient Reinforced Concrete Beams, Yasir Al-Lebban Jan 2017

Polyurethane Fiber Reinforced Polymer Strengthening Of Shear Deficient Reinforced Concrete Beams, Yasir Al-Lebban

Electronic Theses and Dissertations

The use of externally-bonded fiber-reinforced polymer (FRP) composites has been established as an effective means for the strengthening of shear-deficient reinforced concrete (RC) flexural members. Epoxy-based wet layup systems were predominantly employed in previous studies. In this study, carbon FRP pre-impregnated with polyurethane resin is utilized in strengthening shear-deficient RC beams and compared to an epoxy resin. Fourteen small-scale (96 in span, 6 in width, and 12 in height) and five large-scale (132 in span, 12 in width, and 17 in height) flexural specimens were tested, considering FRP system type (polyurethane versus epoxy), size effect, shear span-to-depth ratio, FRP configuration …

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A Framework For Lean Transformation In Developing Countries: The Case Of Saudi Arabian Industry, Murad Andejany Jan 2017

A Framework For Lean Transformation In Developing Countries: The Case Of Saudi Arabian Industry, Murad Andejany

Electronic Theses and Dissertations

Lean is a dynamic, knowledge-driven, and customer focused philosophy that continuously eradicates waste and generates value, with a goal to improve a company's productivity, efficiency, and quality. Successful implementation of lean does not only offer cost reduction and improved quality and productivity, but also provides efficient guidance for organizations to attain significant and continued growth. Although its adoption by companies has proven successful in developed countries, there is no sufficient evidence of its successful implementation in developing countries such as Saudi Arabia. A review of the literature indicates that there is a need to study lean transformation in developing countries …

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A Comprehensive Assessment Of Vehicle-To-Grid Systems And Their Impact To The Sustainability Of Current Energy And Water Nexus, Yang Zhao Jan 2017

A Comprehensive Assessment Of Vehicle-To-Grid Systems And Their Impact To The Sustainability Of Current Energy And Water Nexus, Yang Zhao

Electronic Theses and Dissertations

This dissertation aims to explore the feasibility of incorporating electric vehicles into the electric power grid and develop a comprehensive assessment framework to predict and evaluate the life cycle environmental, economic and social impact of the integration of Vehicle-to-Grid systems and the transportation-water-energy nexus. Based on the fact that electric vehicles of different classes have been widely adopted by both fleet operators and individual car owners, the following questions are investigated: 1. Will the life cycle environmental impacts due to vehicle operation be reduced? 2. Will the implementation of Vehicle-to-Grid systems bring environmental and economic benefits? 3. Will there be …

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The Effectiveness Of Child Restraint And Bicycle Helmet Policies To Improve Road Safety, Claudia Bustamante Jan 2017

The Effectiveness Of Child Restraint And Bicycle Helmet Policies To Improve Road Safety, Claudia Bustamante

Electronic Theses and Dissertations

Analyzing the effect of legislation in children's safety when they travel as motor-vehicle passengers and bicycle riders can allow us to evaluate the effectiveness in transportation policies. The Child Restraint Laws (CRL) and Bicycle Helmet Laws (BHL) were studied by analyzing the nationwide Fatality Analysis Reporting System (FARS) to estimate the fatality reduction as well as drivers' decisions to use Child Restraint Systems (CRS) and bicycle helmets respectively. Differences in legislation could have different effects on traffic fatalities. Therefore, this study presents multiple methodologies to study these effects. In the evaluation of traffic safety issues, several proven statistical models have …

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Evaluation Of The Hurricane Imaging Radiometer (Hirad) Brightness Temperatures, Saleem Sahawneh Jan 2017

Evaluation Of The Hurricane Imaging Radiometer (Hirad) Brightness Temperatures, Saleem Sahawneh

Electronic Theses and Dissertations

The Hurricane Imaging Radiometer (HIRAD) is an experimental, airborne, microwave remote sensor that was developed to measure hurricane surface wind speed and rain rate, and thereby, provide data for scientific research and for the next generation operational hurricane surveillance. The object of this dissertation is to develop objective procedures and techniques that can be used to evaluate and characterize the HIRAD brightness temperature (Tb) image product provided by NASA MSFC. First, the approach that was developed for geolocation (latitude and longitude) accuracy determination of HIRAD image pixels is presented. Using statistical estimation theory, high-contrast HIRAD imagery are compared with high …

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Physical Hydrogeological Modeling Of Florida's Sinkhole Hazard, Adam Perez Jan 2017

Physical Hydrogeological Modeling Of Florida's Sinkhole Hazard, Adam Perez

Electronic Theses and Dissertations

Sinkholes are one of the major geohazards in karst terrain and pose a social, economic, and environmental risk. In Florida, sinkhole-related insurance claims between 2006 and the third quarter of 2010 amounted to $1.4 billion. Approximately 20 % of the United States is underlain by karst terrain formed from the dissolution of soluble rocks and is susceptible to a sinkhole hazard. Particularly, Texas, Florida, Tennessee, Alabama, Missouri, Kentucky, and Pennsylvania are known as sinkhole states. The scope of this study is to develop a physical model to simulate sinkholes (referred to as a sinkhole simulator), which can assess the qualitative …

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Design And Simulation Of Device Failure Models For Electrostatic Discharge (Esd) Event, Meng Miao Jan 2017

Design And Simulation Of Device Failure Models For Electrostatic Discharge (Esd) Event, Meng Miao

Electronic Theses and Dissertations

In this dissertation, the research mainly focused on discussing ESD failure event simulation and ESD modeling, seeking solutions for ESD issues by simulating ESD event and predict possible ESD reliability problem in IC design. The research involves failure phenomenon caused by ESD/ EOS stress, mainly on the thermal failure due to inevitable self-heating during an ESD stress. Standard Complementary Metal-Oxide-Semiconductor (CMOS) process and high voltage Doublediffusion Metal-Oxide-Semiconductor (DMOS) process are used for design of experiment. A multi-function test platform High Power Pulse Instrument (HPPI) is used for ESD event evaluation and device characterization. SPICE-like software ADICE is for back-end simulation. …

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