Electrical and Electronics Commons^™

Autonomous Recovery Of Reconfigurable Logic Devices Using Priority Escalation Of Slack, Naveed Imran

Electronic Theses and Dissertations

Field Programmable Gate Array (FPGA) devices offer a suitable platform for survivable hardware architectures in mission-critical systems. In this dissertation, active dynamic redundancy-based fault-handling techniques are proposed which exploit the dynamic partial reconfiguration capability of SRAM-based FPGAs. Self-adaptation is realized by employing reconfiguration in detection, diagnosis, and recovery phases. To extend these concepts to semiconductor aging and process variation in the deep submicron era, resilient adaptable processing systems are sought to maintain quality and throughput requirements despite the vulnerabilities of the underlying computational devices. A new approach to autonomous fault-handling which addresses these goals is developed using only a uniplex …

Differential Games For Multi-Agent Systems Under Distributed Information, Wei Lin

Electronic Theses and Dissertations

In this dissertation, we consider differential games for multi-agent systems under distributed information where every agent is only able to acquire information about the others according to a directed information graph of local communication/sensor networks. Such games arise naturally from many applications including mobile robot coordination, power system optimization, multiplayer pursuit-evasion games, etc. Since the admissible strategy of each agent has to conform to the information graph constraint, the conventional game strategy design approaches based upon Riccati equation(s) are not applicable because all the agents are required to have the information of the entire system. Accordingly, the game strategy design …

Modeling And Simulation Of All-Electric Aircraft Power Generation And Actuation, David Woodburn

Electronic Theses and Dissertations

Modern aircraft, military and commercial, rely extensively on hydraulic systems. However, there is great interest in the avionics community to replace hydraulic systems with electric systems. There are physical challenges to replacing hydraulic actuators with electromechanical actuators (EMAs), especially for flight control surface actuation. These include dynamic heat generation and power management. Simulation is seen as a powerful tool in making the transition to all-electric aircraft by predicting the dynamic heat generated and the power flow in the EMA. Chapter 2 of this dissertation describes the nonlinear, lumped-element, integrated modeling of a permanent magnet (PM) motor used in an EMA. …

Analysis And Design Optimization Of Multiphase Converter, Kejiu Zhang

Electronic Theses and Dissertations

Future microprocessors pose many challenges to the power conversion techniques. Multiphase synchronous buck converters have been widely used in high current low voltage microprocessor application. Design optimization needs to be carefully carried out with pushing the envelope specification and ever increasing concentration towards power saving features. In this work, attention has been focused on dynamic aspects of multiphase synchronous buck design. The power related issues and optimizations have been comprehensively investigated in this paper. In the first chapter, multiphase DC-DC conversion is presented with background application. Adaptive voltage positioning and various nonlinear control schemes are evaluated. Design optimization are presented …

Rf Power Amplifier And Oscillator Design For Reliability And Variability, Shuyu Chen

Electronic Theses and Dissertations

CMOS RF circuit design has been an ever-lasting research field. It gained so much attention since RF circuits have high mobility and wide band efficiency, while CMOS technology has the advantage of low cost and better capability of integration. At the same time, IC circuits never stopped scaling down for the recent many decades. Reliability issues with RF circuits have become more and more severe with device scaling down: reliability effects such as gate oxide break down, hot carrier injection, negative bias temperature instability, have been amplified as the device size shrinks. Process variability issues also become more predominant as …

Investigation On Electrical Properties Of Rf Sputtered Deposited Bcn Thin Films, Adithya Prakash

Electronic Theses and Dissertations

The ever increasing advancements in semiconductor technology and continuous scaling of CMOS devices mandate the need for new dielectric materials with low-k values. The interconnect delay can be reduced not only by the resistance of the conductor but also by decreasing the capacitance of dielectric layer. Also cross-talk is a major issue faced by semiconductor industry due to high value of k of the inter-dielectric layer (IDL) in a multilevel wiring scheme in Si ultra large scale integrated circuit (ULSI) devices. In order to reduce the time delay, it is necessary to introduce a wiring metal with low resistivity and …

A Novel Nonlinear Mason Model And Nonlinear Distortion Characterization For Surface Acoustic Wave Duplexers, Li Chen

Electronic Theses and Dissertations

Surface acoustic wave (SAW) technology has been in use for well over one century. In the last few decades, due to its low cost and high performance, this technology has been widely adopted in modern wireless communication systems, to build filtering devices at radio frequency (RF). SAW filters and duplexers can be virtually found inside every mobile handset. SAW devices are traditionally recognized as passive devices with high linear signal processing behavior. However, recent deployments of third generation (3G) and fourth generation (4G) mobile networks require the handsets to handle an increasing number of frequency bands with more complex modulation …

Polymer Optical Fibers For Luminescent Solar Concentration, Esmaeil Banaei

Electronic Theses and Dissertations

Luminescent solar concentrators (LSC’s) are promising candidates for reducing the cost of solar power generation. Conventional LSC’s are slab waveguides coated or doped with luminescence materials for absorption and guiding of light to the slab edges in order to convert optical energy into electricity via attached photovoltaic (PV) cells. Exploiting the advantages of optical fiber production, a fiber LSC (FLSC) is presented in this thesis, in which the waveguide is a polymeric optical fiber. A hybrid fiber structure is proposed for an efficient two-stage concentration of incident light, first into a small doped core using a cylindrical micro-lens that extends …

Transient And Distributed Algorithms To Improve Islanding Detection Capability Of Inverter Based Distributed Generation, Mohamed Al Hosani

Electronic Theses and Dissertations

Recently, a lot of research work has been dedicated toward enhancing performance, reliability and integrity of distributed energy resources that are integrated into distribution networks. The problem of islanding detection and islanding prevention (i.e. anti-islanding) has stimulated a lot of research due to its role in severely compromising the safety of working personnel and resulting in equipment damages. Various Islanding Detection Methods (IDMs) have been developed within the last ten years in anticipation of the tremendous increase in the penetration of Distributed Generation (DG) in distribution system. This work proposes new IDMs that rely on transient and distributed behaviors to …

Distributed Extremum Seeking And Cooperative Control For Mobile Cooperative Communication Systems, Said Alabri

Electronic Theses and Dissertations

In this thesis, a distributed extremum seeking and cooperative control algorithm is designed for mobile agents to disperse themselves optimally in maintaining communication quality and maximizing their coverage. The networked mobile agents locally form a virtual multiple-input multipleoutput (MIMO) communication system, and they cooperatively communicate among them by using the decode and forward cooperative communication technique. The outage probability is used as the measure of communication quality, and it can be estimated real-time. A general performance index balancing outage probability and spatial dispersion is chosen for the overall system. The extremum seeking control approach is used to estimate and optimize …

Holistic Representations For Activities And Crowd Behaviors, Berkan Solmaz

Electronic Theses and Dissertations

In this dissertation, we address the problem of analyzing the activities of people in a variety of scenarios, this is commonly encountered in vision applications. The overarching goal is to devise new representations for the activities, in settings where individuals or a number of people may take a part in specific activities. Different types of activities can be performed by either an individual at the fine level or by several people constituting a crowd at the coarse level. We take into account the domain specific information for modeling these activities. The summary of the proposed solutions is presented in the …

Multi-Physics Model Of Key Components In High Efficiency Vehicle Drive, Shao Hua Lin

Electronic Theses and Dissertations

Hybrid Electric Vehicles (HEVs) and Electric Vehicles (EVs) are crucial technologies for the automotive industry to meet society’s demands for cleaner, more energy efficient transportation. Meeting the need to provide power which sustains HEVs and EVs is an immediate area of concern that research and development within the automotive community must address. Electric batteries and electrical motors are the key components in HEV and EV power generation and transmission, and their performance plays very important role in the overall performance of the modern high efficiency vehicles. Therefore, in this dissertation, we are motivated to study the electric batteries, interior permanent …

Monolithically Integrated Broadly Tunable Light Emitters Based On Selectively Intermixed Quantum Wells, Abdullah Zakariya

Electronic Theses and Dissertations

A monolithically integrated broadly tunable MQW laser that utilizes a combined impurity-free vacancy disordering (IFVD) of quantum wells and optical beam steering techniques is proposed and investigated experimentally. The device consists of a beam-steering section and an optical amplifier section fabricated on a GaAs/AlGaAs quantum well (QW) p-i-n heterostructure. The beam steering section forms a reconfigurable optical waveguide that can be moved laterally by applying separately controlled electrical currents to two parallel contact stripes. The active core of the gain section is divided in into selectively intermixed regions. The selective intermixing of the QW in the gain section results in …

Microstrip Patch Electrically Steerable Parasitic Array Radiators, Justin Luther

Electronic Theses and Dissertations

This dissertation explores the expansion of the Electrically Steerable Parasitic Array Radiator (ESPAR) technology to arrays using microstrip patch elements. Scanning arrays of two and three closely-coupled rectangular patch elements are presented, which incorporate no phase shifters. These arrays achieve directive radiation patterns and scanning of up to 26° with maintained impedance match. The scanning is effected by tunable reactive loads which are used to control the mutual coupling between the elements, as well as additional loads which compensate to maintain the appropriate resonant frequency. The design incorporates theoretical analysis of the system of coupled antennas with full-wave simulation. A …

Optimization And Design Of Photovoltaic Micro-Inverter, Qian Zhang

Electronic Theses and Dissertations

To relieve energy shortage and environmental pollution issues, renewable energy, especially PV energy has developed rapidly in the last decade. The micro-inverter systems, with advantages in dedicated PV power harvest, flexible system size, simple installation, and enhanced safety characteristics are the future development trend of the PV power generation systems. The double-stage structure which can realize high efficiency with nice regulated sinusoidal waveforms is the mainstream for the micro-inverter. This thesis studied a double stage micro-inverter system. Considering the intermittent nature of PV power, a PFC was analyzed to provide additional electrical power to the system. When the solar power …

Ultrafast Laser Material Processing For Photonic Applications, Mark Ramme

Electronic Theses and Dissertations

Femtosecond Laser Direct Writing (FLDW) is a viable technique for producing photonic devices in bulk materials. This novel manufacturing technique is versatile due to its full 3D fabrication capability. Typically, the only requirement for this process is that the base material must be transparent to the laser wavelength. The modification process itself is based on non-linear energy absorption of laser light within the focal volume of the incident beam. This thesis addresses the feasibility of this technique for introducing photonic structures into novel dielectric materials. Additionally, this work provides a deeper understanding of the lightmatter interaction mechanism occurring at high …

The Bit Error Rate (Ber) Performance In Multi-Carrier (Ofdm) And Single-Carrier, Saleh M. Albdran

Electronic Theses and Dissertations

The spectacular growth of wireless communication tools has escalated the number of mobile subscribers from almost 700 million in 2000 to more than 4 billion in 2009. The huge number of subscribers has led to several issues with how service is provided. The high user demand has forced developers to overcome the problems of the old analog systems and to introduce OFDM as a promising technique that can fulfill users' high demands. This technique matches well with high data rate connection and provides a higher capacity for the subscribers' usage.

The OFDM, as a multi-carrier, is more complex than the …

Surface Acoustic Wave (Saw) Cryogenic Liquid And Hydrogen Gas Sensors, Brian Fisher

Electronic Theses and Dissertations

This research was born from NASA Kennedy Space Center’s (KSC) need for passive, wireless and individually distinguishable cryogenic liquid and H2 gas sensors in various facilities. The risks of catastrophic accidents, associated with the storage and use of cryogenic fluids may be minimized by constant monitoring. Accidents involving the release of H2 gas or LH2 were responsible for 81% of total accidents in the aerospace industry. These problems may be mitigated by the implementation of a passive (or low-power), wireless, gas detection system, which continuously monitors multiple nodes and reports temperature and H2 gas presence. Passive, wireless, cryogenic liquid level …

Variance In Fade-Time Of A Gamma-Gamma Distributed Irradiance Signal, Troy T. Leclerc

Electronic Theses and Dissertations

Free-space optical communications are predominantly hindered by optical turbulence, an effect caused by temperature and pressure variations within the atmosphere. The result is an optical wave interfering with itself due to multipath propagation via tiny refractive-index fluctuations across the wave-front. Optical communication systems are affected when the channel conditions induce fading in the irradiance signal that is received at the detector. The nature of optical interference imparted by the atmosphere is a random process and therefore the received irradiance signal is often characterized by an appropriate probability density function (PDF). Data collected during past free-space optical experiments in the atmosphere …

Synchronous Communication System For Saw Sensors Interrogation, Maxim Troshin

Electronic Theses and Dissertations

During past two decades a variety of SAW based wireless sensors were invented and research is still in progress. As different frequencies, varied bandwidths, coding techniques and constantly changing post processing algorithms are being implemented, there is a constant need for a universal and adjustable synchronous communication system able to interrogate new generations of SAW sensors. This thesis presents the design of a multiple FPGA based communication system with an operational frequency range of 450MHz-2.2GHz capable of producing user programmed modulated signal. The synchronous receiver is designed to have interchangeable chip, replacement of which would allow adjustment of the receiver’s …

Electromagnetic Environment In Payload Fairing Cavities, Dawn Trout

Electronic Theses and Dissertations

An accurate determination of a spacecraft’s radio frequency electromagnetic field environment during launch and flight is critical for mission success. Typical fairing structures consist of a parabolic nose and a cylindrical core with diameters of 1 to 5 meters resulting in electrically large dimensions for typical operational sources at S, C and X band where the free space wavelength varies from 0.15 m to 0.03 m. These electrically large size and complex structures at present have internal fairing electromagnetic field evaluation that is limited to general approximation methods and some test data. Though many of today’s computational electromagnetic tools can …

A Laser Radar Employing Linearly Chirped Pulses From A Mode-Locked Laser For Long Range, Unambiguous, Sub-Millimeter Resolution Ranging And Velocimetry, Mohammad Umar Piracha

Electronic Theses and Dissertations

Light detection and ranging (lidar) is used for various applications such as remote sensing, altimetry and imaging. In this talk, a linearly chirped pulse source is introduced that generates wavelength-swept pulses exhibiting ~6 nm optical bandwidth with > 20 km coherence length. The chirped pulses are used in an interferometric lidar setup to perform distance measurements with sub-millimeter resolution (using pulses that are a few meters long), at target distances > 10 km, with at least 25 dB signal-to-noise ratio at the receiver. A pulse repetition rate of 20 MHz provides fast update rates, while chirped pulse amplification allows easy amplification of …

Online Path Planning And Control Solution For A Coordinated Attack Of Multiple Unmanned Aerial Vehicles In A Dynamic Environment, Juan Vega-Nevarez

Electronic Theses and Dissertations

The role of the unmanned aerial vehicle (UAV) has significantly expanded in the military sector during the last decades mainly due to their cost effectiveness and their ability to eliminate the human life risk. Current UAV technology supports a variety of missions and extensive research and development is being performed to further expand its capabilities. One particular field of interest is the area of the low cost expendable UAV since its small price tag makes it an attractive solution for target suppression. A swarm of these low cost UAVs can be utilized as guided munitions or kamikaze UAVs to attack …

Action Recognition Using Particle Flow Fields, Kishore Reddy

Electronic Theses and Dissertations

In recent years, research in human action recognition has advanced on multiple fronts to address various types of actions including simple, isolated actions in staged data (e.g., KTH dataset), complex actions (e.g., Hollywood dataset), and naturally occurring actions in surveillance videos (e.g, VIRAT dataset). Several techniques including those based on gradient, flow, and interest-points, have been developed for their recognition. Most perform very well in standard action recognition datasets, but fail to produce similar results in more complex, large-scale datasets. Action recognition on large categories of unconstrained videos taken from the web is a very challenging problem compared to datasets …

Bst-Inspired Smart Flexible Electronics, Ya Shen

Electronic Theses and Dissertations

The advances in modern communication systems have brought about devices with more functionality, better performance, smaller size, lighter weight and lower cost. Meanwhile, the requirement for newer devices has become more demanding than ever. Tunability and flexibility are both long-desired features. Tunable devices are ‘smart’ in the sense that they can adapt to the dynamic environment or varying user demand as well as correct the minor deviations due to manufacturing fluctuations, therefore making it possible to reduce system complexity and overall cost. It is also desired that electronics be flexible to provide conformability and portability. Previously, tunable devices on flexible …

Design And Characterization Of High Temperature Packaging For Wide-Bandgap Semiconductor Devices, Brian Grummel

Electronic Theses and Dissertations

Advances in wide-bandgap semiconductor devices have increased the allowable operating temperature of power electronic systems. High-temperature devices can benefit applications such as renewable energy, electric vehicles, and space-based power electronics that currently require bulky cooling systems for silicon power devices. Cooling systems can typically be reduced in size or removed by adopting wide-bandgap semiconductor devices, such as silicon carbide. However, to do this, semiconductor device packaging with high reliability at high temperatures is necessary. Transient liquid phase (TLP) die-attach has shown in literature to be a promising bonding technique for this packaging need. In this work TLP has been comprehensively …

Lyapunov-Based Control Design For Uncertain Mimo Systems, Zhao Wang

Electronic Theses and Dissertations

In this dissertation. we document the progress in the control design for a class of MIMO nonlinear uncertain system from five papers. In the first part, we address the problem of adaptive control design for a class of multi-input multi-output (MIMO) nonlinear systems. A Lypaunov based singularity free control law, which compensates for parametric uncertainty in both the drift vector and the input gain matrix, is proposed under the mild assumption that the signs of the leading minors of the control input gain matrix are known. Lyapunov analysis shows global uniform ultimate boundedness (GUUB) result for the tracking error under …

Simulation Study Of A Gpram System: Error Control Coding And Connectionism, Steven E. Schultz

Electronic Theses and Dissertations

A new computing platform, the General Purpose Reprsentation and Association Machine is studied and simulated. GPRAM machines use vague measurements to do a quick and rough assessment on a task; then use approximated message-passing algorithms to improve assessment; and finally selects ways closer to a solution, eventually solving it. We illustrate concepts and structures using simple examples.

High Temperature Materials Characterization And Sensor Application, Xinhua Ren

Electronic Theses and Dissertations

This dissertation presents new solutions for turbine engines in need of wireless temperature sensors at temperatures up to 1300oC. Two important goals have been achieved in this dissertation. First, a novel method for precisely characterizing the dielectric properties of high temperature ceramic materials at high temperatures is presented for microwave frequencies. This technique is based on a high-quality (Q)-factor dielectrically-loaded cavity resonator, which allows for accurate characterization of both dielectric constant and loss tangent of the material. The dielectric properties of Silicon Carbonitride (SiCN) and Silicoboron Carbonitride (SiBCN) ceramics, developed at UCF Advanced Materials Processing and Analysis Center (AMPC) are …

Forecasting Volcanic Activity Using An Event Tree Analysis System And Logistic Regression, William N. Junek

Electronic Theses and Dissertations

Forecasts of short term volcanic activity are generated using an event tree process that is driven by a set of empirical statistical models derived through logistic regression. Each of the logistic models are constructed from a sparse and geographically diverse dataset that was assembled from a collection of historic volcanic unrest episodes. The dataset consists of monitoring measurements (e.g. seismic), source modeling results, and historic eruption information. Incorporating this data into a single set of models provides a simple mechanism for simultaneously accounting for the geophysical changes occurring within the volcano and the historic behavior of analog volcanoes. A bootstrapping …