Engineering Commons^™

Radar Based Navigation In Unknown Terrain, Kyle J. Kauffman

Theses and Dissertations

There is a great need to develop non-GPS based methods for positioning and navigation in situations where GPS is not available. This research focuses on the development of an Ultra-Wideband Orthogonal Frequency Division Multiplexed (UWB-OFDM) radar as a navigation sensor in GPS-denied environments. A side-looking vehicle-fixed UWB-OFDM radar is mounted to a ground or aerial vehicle continuously collecting data. A set of signal processing algorithms and methods are developed which use the raw radar data to aide in calculating the vehicle position and velocity via a simultaneous localization and mapping (SLAM) approach. The radar processing algorithms detect strong, persistent, and …

A Nonparametric Approach To Segmentation Of Ladar Images, Eric A. Buschelman

Theses and Dissertations

The advent of advanced laser radar (ladar) systems that record full-waveform signal data has inspired numerous inquisitions which aspire to extract additional, previously unavailable, information about the illuminated scene from the collected data. The quality of the information, however, is often related to the limitations of the ladar camera used to collect the data. This research project uses full-waveform analysis of ladar signals, and basic principles of optics, to propose a new formulation for an accepted signal model. A new waveform model taking into account backscatter reflectance is the key to overcoming specific deficiencies of the ladar camera at hand, …

Exploitation Of Rf-Dna For Device Classification And Verification Using Grlvqi Processing, Donald R. Reising

Theses and Dissertations

This dissertation introduces a GRLVQI classifier into an RF-DNA fingerprinting process and demonstrates applicability for device classification and ID verification. Unlike MDA/ML processing, GRLVQI provides a measure of feature relevance that enables Dimensional Reduction Analysis (DRA) to enhance the experimental-to-operational transition potential of RF-DNA fingerprinting. Using 2D Gabor Transform RF-DNA fingerprints extracted from experimentally collected OFDM-based 802.16 WiMAX and 802.11 WiFi device emissions, average GRLVQI classification accuracy of %C greater than or equal to 90% is achieved using full and reduced dimensional feature sets at SNR greater than or equal to 10.0 dB and SNR greater than or equal to …

Condition-Dependent Risk Assessment Of Large-Scale Grid-Tied Photovoltaic Power Systems, Sherwin Li

Master's Theses

This thesis reviews the methods for evaluating the reliability of large PV systems and techniques for quantifying the impacts of PV interconnection on distribution system reliability. In addition, a comparative study is performed to evaluate the seasonal condition-dependent risk performance of central-inverter and string-inverter grid-tied PV power systems. Major contributions include: 1) risk analysis of seasonal impacts for string and centralized PV systems. Seasonal sensitivities of PV system risks to system structures, temperature variation, solar insolation, and capacitor equivalent series resistance are analyzed; and 2) the incorporation of the effect of operational conditions and the aging failure model into the …

Modeling And Characterization Of Power Distribution Networks With Installed Distributed Generation And Connected Phevs, Santhosh Basineni

Electrical Engineering Theses

This thesis is focused on the modeling and characterization of power distribution networks with installed distributed generation and connected plug-in hybrid electric vehicles (PHEV). A PHEV charging/discharging (bidirectional) model has been developed in MATLAB®-Simulink. Installed photovoltaic systems with varying irradiance rates are modeled and characterized. Moreover, installed wind generators with varying wind speeds are modeled and characterized. Furthermore, the charging and discharging characteristics of connected PHEV are determined. The system characteristics are determined and investigated against the PHEV battery state of charge (SOC).

Modeling The Effects Of The Local Environment On A Received Gnss Signal, Marshall E. Haker

Theses and Dissertations

There is an ongoing need in the GNSS community for the development of high-fidelity simulators which generate data that replicates what can truly be expected from a challenging environment such as an urban canyon or an indoor environment. The algorithm developed for use in the research in this dissertation, the Signal Decomposition and Parameterization Algorithm (SDPA), is presented in order to respond to this need. This algorithm is designed to decompose a signal received using a GNSS recording and playback system and output parameters that can be used to reconstruct the effects on the signal of the environment local to …

Single-Stage Power Electronic Converters With Combined Voltage Step-Up/Step-Down Capability, Navid Golbon

Electronic Thesis and Dissertation Repository

Power electronic converters are typically either step-down converters that take an input voltage and produce an output voltage of low amplitude or step-up converters that take an input voltage and produce an output voltage of higher amplitude. There are, however, applications where a converter that can step-up voltage or step-down voltage can be very useful, such as in applications where a converter needs to operate under a wide range of input and output voltage conditions such as a grid-connected solar inverter. Such converters, however, are not as common as converters that can only step down or step up voltage because …

Novel Control And Harmonics Impact Of Pv Solar Farms, Byomakesh Das

Electronic Thesis and Dissertation Repository

This thesis presents a novel application of Photovoltaic (PV) solar system inverter, both during night and day, as a dynamic reactive power compensator STATCOM. This technology, termed PV-STATCOM, is designed and developed for power factor correction in the networks of two utilities: Bluewater Power, Sarnia, and London Hydro. This thesis further describes for the first time, the harmonic impact studies on a utility distribution network in presence of the largest PV solar farm in Canada.

This novel utilization of a PV-STATCOM for power factor correction of induction motor loads is demonstrated with (i) electromagnetic transient simulation in EMTDC/PSCAD software, (ii) …

Reliability Techniques For Data Communication And Storage In Fpga-Based Circuits, Yubo Li

Theses and Dissertations

This dissertation studies the effects of radiation-induced single-event upsets (SEUs) on field-programmable gate array(FPGA)-based circuits. It analyzes and quantifies a special case in data communication, that is, the synchronization issue of signals when they are sent across clock domains in triple modular redundancy (TMR) circuits with the presence of SEUs. After demonstrating that synchronizing errors cannot be eliminated in such case, this dissertation continues to present novel synchronizer designs that can guarantee reliable synchronization of triplicated signals. Fault injection tests then show that the proposed synchronizers provide between 6 and 10 orders of magnitude longer mean time to failure (MTTF) …

Wireless Telemetry System For Implantable Sensors, Kyle G. Fricke

Electronic Thesis and Dissertation Repository

Advanced testing of medical treatments involves experimentation on small laboratory animals, such as genetically modified mice. These subjects are used to help researchers develop medication and cures for humans. To understand the effects of the treatments, innovative telemetry systems are developed, that enable remote real-time cardiac monitoring. The latest research in the field of cardiac monitoring has revealed two major limitations with wireless implantable systems: a) the current size of implantable electronics limits the physical size of the system to larger subjects; and b) the systems only interface with one sensor type (e.g., pressure sensor only). This research focuses on …

Efficient Estimation For Small Multi-Rotor Air Vehicles Operating In Unknown, Indoor Environments, John Charles Macdonald

Theses and Dissertations

In this dissertation we present advances in developing an autonomous air vehicle capable of navigating through unknown, indoor environments. The problem imposes stringent limits on the computational power available onboard the vehicle, but the environment necessitates using 3D sensors such as stereo or RGB-D cameras whose data requires significant processing. We address the problem by proposing and developing key elements of a relative navigation scheme that moves as many processing tasks as possible out of the time-critical functions needed to maintain flight. We present in Chapter 2 analysis and results for an improved multirotor helicopter state estimator. The filter generates …

Development And Evaluation Of A Real-Time Framework For A Portable Assistive Hearing Device, Aleksandar Dimitrov Mihaylov

Electronic Thesis and Dissertation Repository

Testing and verification of digital hearing aid devices, and the embedded software and algorithms can prove to be a challenging task especially taking into account time-to-market considerations. This thesis describes a PC based, real-time, highly configurable framework for the evaluation of audio algorithms. Implementation of audio processing algorithms on such a platform can provide hearing aid designers and manufacturers the ability to test new and existing processing techniques and collect data about their performance in real-life situations, and without the need to develop a prototype device. The platform is based on the Eurotech Catalyst development kit and the Fedora Linux …

Dynamic Modeling, Trajectory Generation And Tracking For Towed Cable Systems, Liang Sun

Theses and Dissertations

In this dissertation, we focus on the strategy that places and stabilizes the path of an aerial drogue, which is towed by a mothership aircraft using a long flexible cable, onto a horizontally flat orbit by maneuvering the mothership in the presence of wind. To achieve this goal, several studies for towed cable systems are conducted, which include the dynamic modeling for the cable, trajectory generation strategies for the mothership, trajectory-tracking control law design, and simulation and flight test implementations. First, a discretized approximation method based on finite element and lumped mass is employed to establish the mathematical model for …

Control Design And Filtering For Wireless Networked Systems, Xiao Ma

Doctoral Dissertations

This dissertation is concerned with estimation and control over wireless networked systems. Several problems are addressed, including estimator design over packet loss links, control and estimation over cognitive radio systems, modeling and prediction of wireless sensor networks (WSNs), and localization with the Theater Positioning System (TPS). The first problem addressed is the state estimation of a discrete-time system through a packet loss link modeled by a Bernoulli random variable. The optimal filter is derived by employing exact hybrid filtering. The performance of the optimal filter is illustrated by numerical simulations. Next, we consider the problem of estimation and control over …

A Low-Power, Highly Stabilized Three-Electrode Potentiostat Using Subthreshold Techniques, Melika Roknsharifi

Doctoral Dissertations

Implantable micro- and nano- sensors and implantable microdevices (IMDs) have demonstrated potential for monitoring various physiological parameters such as glucose, lactate, CO₂ [carbon dioxide], pH, etc. Potentiostats are essential components of electrochemical sensors such as glucose monitoring devices for diabetic patients. Diabetes is a metabolic disorder associated with insufficient production or inefficient utilization of insulin. The most important role of this enzyme is to regulate the metabolic breakdown of glucose generating the necessary energy for human activities. Diabetic patients typically monitor their blood glucose levels by pricking a fingertip with a lancing device and applying the blood to a …

Techniques For Wireless Channel Modeling In Harsh Environments, Phani Teja Kuruganti

Doctoral Dissertations

With the rapid growth in the networked environments for different industrial, scientific and defense applications, there is a vital need to assure the user or application a certain level of Quality of Service (QoS). Environments like the industrial environment are particularly harsh with interference from metal structures (as found in the manufacturing sector), interference generated during wireless propagation, and multipath fading of the radio frequency (RF) signal all invite novel mitigation techniques. The challenge of achieving the benefits like improved energy efficiency using wireless is closely coupled with maintaining network QoS requirements. Assessment and management of QoS needs to occur, …

A Highly Integrated Gate Driver With 100% Duty Cycle Capability And High Output Current Drive For Wide-Bandgap Power Switches In Extreme Environments, Robert Lee Greenwell

Doctoral Dissertations

High-temperature integrated circuits fill a need in applications where there are obvious benefits to reduced thermal management or where circuitry is placed away from temperature extremes. Examples of these applications include aerospace, automotive, power generation, and well-logging. This work focuses on the automotive applications, in which the growing demand for hybrid electric vehicles (HEVs), plug-in hybrid electric vehicles (PHEVs), and fuel cell vehicles (FCVs) has increased the need for high-temperature electronics that can operate at the extreme ambient temperatures that exist under the hood, which can be in excess of 150°C. Silicon carbide (SiC) and other wide-bandgap power switches that …

Optimization And Learning In Energy Efficient Cognitive Radio System, Kun Zheng

Doctoral Dissertations

Energy efficiency and spectrum efficiency are two biggest concerns for wireless communication. The constrained power supply is always a bottleneck to the modern mobility communication system. Meanwhile, spectrum resource is extremely limited but seriously underutilized.

Cognitive radio (CR) as a promising approach could alleviate the spectrum underutilization and increase the quality of service. In contrast to traditional wireless communication systems, a distinguishing feature of cognitive radio systems is that the cognitive radios, which are typically equipped with powerful computation machinery, are capable of sensing the spectrum environment and making intelligent decisions. Moreover, the cognitive radio systems differ from traditional wireless …

A Charge-Recycling Scheme And Ultra Low Voltage Self-Startup Charge Pump For Highly Energy Efficient Mixed Signal Systems-On-A-Chip, Chandradevi Ulaganathan

Doctoral Dissertations

The advent of battery operated sensor-based electronic systems has provided a pressing need to design energy-efficient, ultra-low power integrated circuits as a means to improve the battery lifetime. This dissertation describes a scheme to lower the power requirement of a digital circuit through the use of charge-recycling and dynamic supply-voltage scaling techniques. The novel charge-recycling scheme proposed in this research demonstrates the feasibility of operating digital circuits using the charge scavenged from the leakage and dynamic load currents inherent to digital design. The proposed scheme efficiently gathers the “ground-bound” charge into storage capacitor banks. This reclaimed charge is then subsequently …

Data Mining And Machine Learning Applications Of Wide-Area Measurement Data In Electric Power Systems, Penn Norris Markham

Doctoral Dissertations

Wide-area measurement systems (WAMS) are quickly becoming an important part of modern power system operation. By utilizing the Global Positioning System, WAMS offer highly accurate time-synchronized measurements that can reveal previously unobtainable insights into the grid’s status. An example WAMS is the Frequency Monitoring Network (FNET), which utilizes a large number of Internet-connected low-cost Frequency Disturbance Recorders (FDRs) that are installed at the distribution level.

The large amounts of data collected by FNET and other WAMS present unique opportunities for data mining and machine learning applications, yet these techniques have only recently been applied in this domain. The research presented …

The Architecture Selection, Design, And Discharge Modeling Of A Passive Compensation, Iron-Core, Two-Phase, Permanent Magnet Compulsator To Power A Small Railgun Platform, Collin Macgregor

Aerospace Engineering

The goal of this project was to design and build a compensated pulsed alternator, or compulsator, to power the Cal Poly Electromagnetic Railgun Mark 1.1. This project examines the feasibility of implementing mechanical pulsed power supplies for repeatable use with a railgun load for orbital debris hypervelocity testing. The final system architecture chosen was a passively compensated, iron-core, 2-phase, permanent magnet compulsator. The Cal Poly Compulsator will be capable of storing 45 kJ of mechanical energy with a peak operating speed of 5,000 rpm at 190 V. Theoretical calculations resulted in the following predicted electrical performance values: a peak output …

Fuzzy Logic Controller For Parallel Plug-In Hybrid Vehicle, Sk. Khairul Hasan

Theses and Dissertations

Hybrid electric vehicles combine two methods for propelling a vehicle. In a parallel hybrid vehicle, the two propulsion methods work in parallel to meet the total power demand. Among different combination of power sources, internal combustion engine and electric motor drive system are the most popular because of their availability and controllability. Plug-in hybrid vehicle is the latest version in hybrid vehicle family. In plug-in hybrid vehicle, battery is directly recharged from the electrical power grid and it can be used for a long distance with higher efficiency. Most of the hybrid vehicles on the road are parallel in nature …

Scr-Based Wind Energy Conversion Circuitry And Controls For Dc Distributed Wind Farms, Ravi Nanayakkara

Theses and Dissertations

The current state of art for electrical power generated by wind generators are in alternating current (AC). Wind farms distribute this power as 3-phase AC. There are inherent stability issues with AC power distribution. The grid power transfer capacity is limited by the distance and characteristic impedance of the lines. Furthermore, wind generators have to implement complicated, costly, and inefficient back-to-back converters to generate AC. AC distribution does not offer an easy integration of energy storage. To mitigate drawbacks with AC generation and distribution, direct current (DC) generation and high voltage direct current (HVDC) distribution for the wind farms is …

Multi-Level Medium Voltage Inverter For Dc Distributed Wind Farm To Establish Grid Interface And Provide Ancillary Support, Yogesh Popatlal Patel

Theses and Dissertations

Wind energy has gained in popularity in recent years due to cost, security and environmental concerns associated with conventional energy sources like fossil fuels. However, the utilization of wind energy in power systems creates many technical and non-technical challenges that need to be addressed for successful integrations. The main technical issues related to wind energy are its uncertainty and variability and their impacts on stability, reliability and quality of the electric power. In systems with high wind energy penetrations, unlike conventional generations, sudden changes in active and/or reactive power demand cannot be supported by wind energy. This lack of demand …

Development Of Mems-Based Corrosion Sensor, Feng Pan

Graduate Theses and Dissertations

This research is to develop a MEMS-based corrosion sensor, which is used for monitoring uniform, galvanic corrosion occurring in infrastructures such as buildings, bridges. The corrosion sensor is made up of the composite of micro/nano metal particles with elastomers. The mechanism of corrosion sensor is based on the mass transport of corrosive species through the sensor matrix. When the metal particles in the matrix corrode, the electrical resistivity of the material increases due to increasing particle resistances or reduction of conducting pathways. The corrosion rate can be monitored by detecting the resistivity change in sensing elements. The life span of …

Image Segmentation For Quantification Of Air-Water Interface In Micro-Ct Soil Images, Kranthi Kumar Potteti

UNLV Theses, Dissertations, Professional Papers, and Capstones

Soils are complex environments comprising various biological (roots, water, air etc) and physical constituents (minerals, aggregates, etc). Synchrotron radiation based X-ray microtomography (XMT) is widely used in extracting qualitative and quantitative information regarding spatial distribution of biological and physical soil constituents. Segmentation of these micro-CT soil images is of interest to geologists, hydrologists, civil and petroleum engineers and soil scientists. In this present work, we study and implement segmentation algorithms for microhydrology studies, specifically for soil water conductivity. Three well-known image segmentation algorithms are studied for evaluating their performance for the task. We demonstrate the problems and ways to segment …

Methodology For Standby Leakage Power Reduction In Nanometer-Scale Cmos Circuits, Jae Woong Chun

Electrical Engineering and Computer Science - Dissertations

In nanometer-scale CMOS technology, leakage power has become a major component of the total power dissipation due to the downscaling of threshold voltage and gate oxide thickness. The leakage power consumption has received even more attention by increasing demand for mobile devices. Since mobile devices spend a majority of their time in a standby mode, the leakage power savings in standby state is critical to extend battery lifetime. For this reason, low power has become a major factor in designing CMOS circuits.

In this dissertation, we propose a novel transistor reordering methodology for leakage reduction. Unlike previous technique, the proposed …

Dynamic Thermal Management For Microprocessors, Yang Ge

Electrical Engineering and Computer Science - Dissertations

In deep submicron era, thermal hot spots and large temperature gradients significantly impact system reliability, performance, cost and leakage power. Dynamic thermal management techniques are designed to tackle the problems and control the chip temperature as well as power consumption. They refer to those techniques which enable the chip to autonomously modify the task execution and power dissipation characteristics so that lower-cost cooling solutions could be adopted while still guaranteeing safe temperature regulation. As long as the temperature is regulated, the system reliability can be improved, leakage power can be reduced and cooling system lifetime can be extended significantly.

Multimedia …

Method Of Moments Analysis Of An Aperture In A Thick Ground Plane, Ahmet Burak Olcen

Electrical Engineering and Computer Science - Dissertations

The problem of electromagnetic scattering from and transmission through an arbitrarily shaped aperture is considered. The aperture is in a thick infinite perfectly conducting ground plane. The conducting walls of the cavity inside the ground plane are of arbitrary shape. The apertures at both ends of the cavity are also of arbitrary shape. The structure is illuminated by an incident plane electromagnetic wave. The Green's function for this complicated problem is almost impossible to determine. Therefore the surface equivalence principle is used to reduce this complex problem into three simpler ones. Each such problem consists of equivalent surface currents radiating …

Design, Modeling And Analysis Of Non-Classical Field Effect Transistors, Peijie Feng

Electrical Engineering and Computer Science - Dissertations

Transistor scaling following per Moore's Law slows down its pace when entering into nanometer regime where short channel effects (SCEs), including threshold voltage fluctuation, increased leakage current and mobility degradation, become pronounced in the traditional planar silicon MOSFET. In addition, as the demand of diversified functionalities rises, conventional silicon technologies cannot satisfy all non-digital applications requirements because of restrictions that stem from the fundamental material properties. Therefore, novel device materials and structures are desirable to fuel further evolution of semiconductor technologies. In this dissertation, I have proposed innovative device structures and addressed design considerations of those non-classical field effect transistors …