Electrical and Computer Engineering Commons^™

Holographic-Based Leaky Wave Antennas And Phonon-Enhanced Waveguides For Infrared Applications, Franklin Muriuki Manene

Theses and Dissertations

This work contributes to critical requirements for antenna-coupled detection applications: 1) large capture cross section with design control of angular response and 2) long propagation lengths of complex signals. Antenna-coupled detectors for infrared applications provide appreciable capture cross sections while delivering signals to sub-wavelength-sized detectors. In this work, leaky-wave antennas are considered for the first time in the infrared spectrum. Design characterization of angular radiation patterns as well as polarization is presented. While leaky-wave antennas hold great promise for enhancing capture cross section, thus narrowing the field of view of the detector, there is a parallel need to preserve coherent …

Characterization Of Electron Number Density Of Rocket Exhaust Plumes Through Microwave Transmissions, Jorge Torres

Doctoral Dissertations and Master's Theses

Charged rocket plumes generally exceed the length of their source vehicles, and offer lightning a favorable path to ground. Rocket plumes enhance the induced transient currents in flight electronics, and increase the risk of vehicle failure. The affinity of lightning to the plume can be associated with the plume's electrical properties, which are coupled to plasma characteristics including the electron number density. However, the electron number density of rocket plumes is not well-known. In this study, the electron number density is characterized through data from static rocket firings. A model of the plume in finite difference time domain (FDTD) simulations …

Experimental Validation Of A New Distributed Cooperative Control Algorithm For Multi-Agent Systems With Switching Communication Topologies And Time-Delays, Junzhen Shao

Doctoral Dissertations and Master's Theses

In this thesis, we present practical experimental results to demonstrate a control law for consensus of multiagent systems with switching topologies and time delays. The nonlinear control law utilizes discontinuous cooperative control gains and uses contraction mapping to achieve consensus of multiagent systems. The testing platform we used consists of a number of mobile robots and software simulations both in Matlab and Microsoft Studio C++. We present the effectiveness of the control law design by Aria mobile robots with applications in distributed cooperative formation control. Computer simulations and hardware experiments presented include point consensus control and formation control, both with …

Design Of A High Performance Silicon Carbide Cmos Operational Amplifier, Shaila Amin Bhuyan

Graduate Theses and Dissertations

This thesis presents the design, simulation, layout and test results of a silicon carbide (SiC) CMOS two-stage operational amplifier (op amp) with NMOS input stage. The circuit has been designed to provide a stable open-loop voltage gain (60 dB), unity-gain bandwidth (around 5 MHz) and maintain a high CMRR and PSRR within a useful input common mode range over process corners and a wide temperature range (25 °C - 300 °C). Between the two stages a Miller compensation topology is placed to improve the phase margin (around 45°). Due to the comparatively high threshold voltage values of transistors in SiC, …

Application Of Femtosecond Laser Surface Processed Electrodes In Electrolysis Of Water, Christopher K. Wilson

Department of Electrical and Computer Engineering: Dissertations, Theses, and Student Research

Femtosecond laser surface processing (FLSP) is a machining technique used to develop functionalized surfaces consisting of micro and nano-scale features. Metal electrodes processed using this technique can be used in water electrolysis to facilitate more efficient hydrogen and oxygen gas production. This thesis explores the electrochemical behavior of femtosecond laser processed 316SS electrodes in water electrolysis. The multi-scale surface structure size and separation were controlled through laser fluence and incident laser pulse count. The electrodes were studied in a three electrode electrolysis cell containing a 3M KOH(aq) electrolyte, FLSP 316SS working electrode, 316SS counter electrode, and Hg/HgO reference electrode. Through …

Design And Implementation Of An Instruction Set Architecture And An Instruction Execution Unit For The Rez9 Coprocessor System, Daniel Spencer Anderson

UNLV Theses, Dissertations, Professional Papers, and Capstones

While the use of RNS has provided groundbreaking theory and progress in this field, the applications still lack viable testing platforms to test and verify the theory. This Thesis outlines the processing of developing an instruction set architecture (ISA) and an instruction execution unit (IEU) to help make the first residue based general processor a viable testing platform to address the mentioned problems.

Consider a 32-bit ripple adder. The delay on this device will be 32N where N is the delay for each adder to complete its operation. The delay of this process is due to the need to propagate …

Induction Of Differentiation Of Dental Pulp-Derived Mesenchymal Stem Cells (Dpsc), Aubrey Young

UNLV Theses, Dissertations, Professional Papers, and Capstones

Mesenchymal stem cells are derived from a variety of human tissues and are being bioengineered and studied for possible uses in the advancement of medicine. Recent efforts are being focused on Dental Pulp Stem Cells (DPSC's) due to the accessibility of this tissue. Many factors influence DPSC quality and quantity, including the specific methods used to isolate, collect, concentrate, and store these isolates once they are removed. Ancillary factors, such as the choice of media, the selection of early versus late passage cells, and cryopreservation techniques may also influence the differentiation potential and proliferative capacity of DPSC isolates.

The objective …

A Phase-Locked Loop In High-Temperature Silicon Carbide And General Design Methods For Silicon Carbide Integrated Circuits, Paul Shepherd

Graduate Theses and Dissertations

Silicon carbide (SiC) has long been considered for integrated circuits (ICs). It offers several advantages, including wider temperature range, larger critical electric field, and greater radiation immunity with respect to Silicon (Si). At the same time, it suffers from challenges in fabrication consistency and lower transconductance which the designer must overcome. One of the recent SiC IC processes developed is the Raytheon High-Temperature Silicon Carbide (HTSiC) complementary MOSFET process. This process is one of the first to offer P channel MOSFETs and, as a result, a greater variety of circuits can be built in it.

The behavior of SiC MOSFETs …

Design Of System Level Control For A Residential Power Router, Fahad Hossain

Graduate Theses and Dissertations

This thesis presents the overall power flow and load management system for a 2 kW residential power router. The objective is to satisfy the residential load demand with cost savings by managing the energy sources including PV, battery, generator, and grid. The power flow management system algorithm is developed both for grid-connected mode and island mode. This algorithm involves the battery state of charge estimation, available PV power, load demand and electricity grid pricing. The residential load management algorithm is also developed using PV power prediction and load power prediction acquired for a day.¬ A Labview GUI is also developed …

Design, Simulation And Implementation Of Three-Phase Bidirectional Dc-Dc Dual Active Bridge Converter Using Sic Mosfets, Tariq Aldawsari

Graduate Theses and Dissertations

The use of SiC-based martials in fabricating power semiconductor devices has shown more interest than conventional silicon-based. Its promising abilities to improve the performance of power electronic systems made it a valuable choice in building high power DC-DC converters. This thesis presents the design and implementation of a three-phase bidirectional DC-DC Dual Active Bridge using SiC MOSFETs. The proposed circuit is first built in Matlab for simulation analysis. Then a phase shift modulation controller is designed in Simulink to test the simulation circuit. The controls are then integrated through an FPGA to test the prototype. Simulations and experimental results are …

Integration Of Energy Storage Into A Future Energy System With A High Penetration Of Distributed Photovoltaic Generation, Arthur K. Barnes

Graduate Theses and Dissertations

Energy storage units (ESU) are increasingly used in electrical distribution systems because they can perform many functions compared with traditional equipment. These include peak shaving, voltage regulation, frequency regulation, provision of spinning reserve, and aiding integration of renewable generation by mitigating the effects of intermittency.

As is the case with other equipment on electric distribution systems, it is necessary to follow appropriate methodologies in order to ensure that ESU are installed in a cost-effective manner and their benefits are realized. However, the necessary methodologies for integration of ESU have not kept pace with developments in both ESU and distribution systems. …

Designing And Implementing A Micro-Controller Based Primary-Side Sensing Flyback Converter For Leds Driver, Nam Nhat Tran

Graduate Theses and Dissertations

The fast development of LED and its applications has enabled a new generation of lighting device with higher efficiency and long lifespan. By employing a primary-side sensing flyback converter and the PIC18F micro-controller series, an LED driver could achieve two important features: (1) the compatibility with the available lighting fixtures, and (2) reducing unit price. The flyback converter was chosen for its simplicity, competitive low cost, and its ability to provide a constant output current, a necessarily important factor to an LED driver. Meanwhile, the PIC18F micro-controller series offer numerous advanced features which include but not limited to pulse-width modulation …

Homogenous Ensemble Phonotactic Language Recognition Based On Svm Supervector Reconstruction, Wei-Wei Liu, Wei-Qiang Zhang, Michael T. Johnson, Jia Liu

Electrical and Computer Engineering Faculty Research and Publications

Currently, acoustic spoken language recognition (SLR) and phonotactic SLR systems are widely used language recognition systems. To achieve better performance, researchers combine multiple subsystems with the results often much better than a single SLR system. Phonotactic SLR subsystems may vary in the acoustic features vectors or include multiple language-specific phone recognizers and different acoustic models. These methods achieve good performance but usually compute at high computational cost. In this paper, a new diversification for phonotactic language recognition systems is proposed using vector space models by support vector machine (SVM) supervector reconstruction (SSR). In this architecture, the subsystems share the same …

Analysis, Validation, And Improvement Of High-Resolution Wind Estimates From The Advanced Scatterometer (Ascat), Jeffrey Richard Blodgett

Theses and Dissertations

The standard L2B ocean wind product from the Advanced Scatterometer (ASCAT) is retrieved as a 25 km product on a 12.5 km grid. Ultra-high resolution (UHR) processing allows ASCAT wind retrieval on a high-resolution 1.25 km grid. Ideally, such a high-resolution sample grid provides wind information down to a 2.5 km scale, allowing better analysis of winds with high spatial variability such as those in near-coastal regions and storms. Though the wind field is sampled on a finer grid, the actual data resolution needs to be validated. This thesis provides an analysis and validation of ASCAT UHR wind estimates in …

B1 Mapping For Magnetic Resonance Imaging, Daniel Joseph Park

Theses and Dissertations

Magnetic Resonance Imaging (MRI) is a non-ionizing form of medical imaging which has practical uses in diagnosing, characterizing, and studying diseases in vivo. Current clinical practice utilizes a highly trained radiologist to view MR images and qualitatively diagnose, characterize, or study a disease. There is no easy way to compare qualitative data. That is why developing quantitative measures in MRI show promise. Quantitative measures of disease can be compared across a population, MRI sites, and over time. Osteoarthritis is one disease where those who have it may benefit from the development of quantitative MRI measures. Those benefits may include earlier …

Radiation-Induced Effects In Chalcogenide-Based Memory Devices And Films, Kasandra Wolf

Boise State University Theses and Dissertations

Continued scaling of memory devices has produced many issues for the current foremost non-volatile memory—the flash memory—leading to the emergence of a wide variety of alternative memory solutions. Redox Conductive Bridge Memory (RCBM) is one such solution that has shown great promise in recent years. However, the performance of these devices under radiation conditions has not been explored in detail. This work investigates the effects of x-rays and electron bombardment on chalcogenide glasses and RCBM devices based on these materials.

RCBM devices are a form of Resistance Change Memory, which rely on two distinct resistive states to represent the binary …

Neural Network Dynamic Progamming Constrained Control Of Distributed Parameter Systems Governed By Parabolic Partial Differential Equations With Application To Diffusion-Reaction Processes, Behzad Talaei, Hao Xu, S. Jagannathan

Electrical and Computer Engineering Faculty Research & Creative Works

In this paper, a novel neural network (NN) adaptive dynamic programming (ADP) control scheme for distributed parameter systems (DPS) governed by parabolic partial differential equations (PDE) is introduced in the presence of control constraints and unknown system dynamics. First, Galerkin method is utilized to develop a relevant reduced order system which captures the dominant dynamics of the DPS. Subsequently, a novel control scheme is proposed over finite horizon by using NN ADP. To relax the requirement of system dynamics, a novel NN identifier is developed. More-over, a second NN is proposed to estimate online the time-varying non-quadratic value function from …

An Analysis Of Hybrid Energy System: A Case Study, Yading Yang

Morehead State Theses and Dissertations

A Thesis Presented to the Faculty of the College of Science and Technology Morehead State University in Partial Fulfillment of the Requirements for the Degree Master of Science by Yading Yang on November 24, 2014.

Low-Power Analog Processing, Daniel J. White

Department of Electrical and Computer Engineering: Dissertations, Theses, and Student Research

This dissertation presents the analog harmonic transform (AHT) and a first implementation in an integrated circuit. The transform is designed for a regular and simple hardware structure. It provides coefficients relating to an input signal's spectrum. These coefficients also have a simple relationship to the signal's Fouri\'er series coefficients.

The AHT is defined in its ideal form and evaluated for two example signal classification applications. Both military vehicle and bearing fault classification tasks are presented which validate the ability of a neural network to use the AHT coefficients to correctly classify the input signals. Because any real use of the …

Clustering-Based Methodology For Optimal Residential Time Of Use Design Structure, Maigha, M. L. Crow

Electrical and Computer Engineering Faculty Research & Creative Works

A price responsive demand (PRD) market has been perceived as the future of electricity markets with the capability of achieving economic benefits. It lays the foundation of demand response at the customer level. Time of use structures have been implemented widely to achieve load reshaping. This paper introduces a clustering-based methodology for obtaining optimal time of use structures (optimal number of levels and rate durations) based on historical load profiles and real-time prices. The study takes into account variation in weekday and weekend load profiles and also seasonal variations. A new hybrid policy that bridges the gap between seasonal time-of-use …

Robust Adaptive Channel Estimation In Mimo Underwater Acoustic Communications, Zengli Yang, Yahong Rosa Zheng

Electrical and Computer Engineering Faculty Research & Creative Works

For underwater acoustic (UWA) communications, a robust iterative channel estimation based minimum mean-square-error (MMSE) adaptive turbo equalizer is proposed and studied for multiple-input multiple-output (MIMO) detection. Rather than the classical MMSE or normalized least mean squares (NLMS) estimation algorithms, the improved proportionate NLMS (IPNLMS) is adopted for the iterative MIMO channel estimator. The MIMO channel estimation is performed jointly with the MMSE equalizer and the maximum a posteriori probability (MAP) decoder. With inter-block interference removed, the MIMO MMSE equalization is performed with overlapped information subblocks without guard intervals, thus a high transmission efficiency is guaranteed, and performance degradation is prevented. …

A Combined Method For Segmentation And Registration For An Advanced And Progressive Evaluation Of Thermal Images, Emilio Z. Barcelos, Walmir Matos Caminhas, Eraldo Ribeiro, Eduardo Mendonça Pimenta, Reinaldo Martinez Palhares

Electrical Engineering and Computer Science Faculty Publications

In this paper, a method that combines image analysis techniques, such as segmentation and registration, is proposed for an advanced and progressive evaluation of thermograms. The method is applied for the prevention of muscle injury in high-performance athletes, in collaboration with a Brazilian professional soccer club. The goal is to produce information on spatio-temporal variations of thermograms favoring the investigation of the athletes’ conditions along the competition. The proposed method improves on current practice by providing a means for automatically detecting adaptive body-shaped regions of interest, instead of the manual selection of simple shapes. Specifically, our approach combines the optimization …

Detection Of Variable Retention Time In Dram, Neraj Kumar

Dissertations and Theses

This thesis investigates a test method to detect the presence of Variable Retention Time (VRT) bits in manufactured DRAM. The VRT bits retention time is modeled as a 2-state random telegraph process that includes miscorrelation between test and use. The VRT defect is particularly sensitive to test and use conditions. A new test method is proposed to screen the VRT bits by simulating the use conditions during manufacturing test. Evaluation of the proposed test method required a bit-level VRT model to be parameterized as a function of temperature and voltage conditions. The complete 2-state VRT bit model combines models for …

Stable And Metastable Nanowires Displaying Locally Controllable Properties, Eli A. Sutter, Peter Werner Sutter

Department of Electrical and Computer Engineering: Faculty Publications

(57) ABSTRACT Vapor-liquid-solid growth of nanowires is tailored to achieve complex one-dimensional material geometries using phase diagrams determined for nanoscale materials. Segmented one-dimensional nanowires having constant composition dis play locally variable electronic band structures that are deter mined by the diameter of the nanowires. The unique electrical and optical properties of the segmented nanowires are exploited to form electronic and optoelectronic devices. Using gold-germanium as a model system, in situ transmis sion electron microscopy establishes, for nanometer-sized Au Ge alloy drops at the tips of Ge nanowires (NWs), the parts of the phase diagram that determine their temperature dependent equilibrium …

A Low-Power Compact Nuclear Quadrupole Resonance (Nqr) Based Explosive Detection System, Xinwang Zhang

Department of Electrical and Computer Engineering: Dissertations, Theses, and Student Research

Abandoned landmines and terrorist bomb attacks are severe issues threatening our society. These issues necessitate the development of prompt and accurate explosive detection systems. The detection mechanisms commonly-used nowadays usually search for explosive containers, which suffer numerous false alarms caused by external detection circumstance changes. Alternatively, explosive substances inside the bombs and landmines can be detected by means of biology, chemistry and physics techniques. Nuclear Quadrupole Resonance (NQR) detection technology has proven to be a highly effective solution for detecting explosives unambiguously.

In this work, a portable NQR-based explosive detection system that employs state-of-the-art semiconductor technologies is presented. This system …

A New Approach For Efficient Analysis Of Large Finite Periodic Structures, Xiaoyan Y.Z. Xiong, Ling Ling Meng, Li (Lijun) Jun Jiang, Wei E.I. Sha, Fan Yang

Electrical and Computer Engineering Faculty Research & Creative Works

Periodic structures have attracted much attention in the past decades due to numerous applications such as metamaterials, antenna arrays, frequency selective surface (FSS), photonic band gap (PBG) or electromagnetic band gap (EBG) structures, etc. Infinite periodic structures are impossible in a realistic fabrication. When truncating infinite periodic structures, discontinuities occur at the interface and surface waves will be excited according to mode conversion, which leads to the edge effect of finite periodic structures. The prediction of wave natures in the edge cells of finite periodic structures is an indispensable procedure during the design of finite periodic structures. The conventional element-by-element …

Distributive Radiation Characterization Based On The Peec Method, Ying S. Cao, Li (Lijun) Jun Jiang, Albert E. Ruehli

Electrical and Computer Engineering Faculty Research & Creative Works

The intentional and unintentional radiations are of great importance to wireless power transfer at the low frequency regime and antenna signal transportation at the higher frequency regime. Due to the rising speed of digital systems and thereby broad bandwidth of signal channels at all levels of electronic devices, it becomes more essential than ever to quantitively analyze, model, and illustrate how the energy is leaked out and which part is a greater contributor to the wanted or unwanted radiation.

Field-Limited Migration Of Li-Ions In Li-Ion Battery, Fuqian Yang

Chemical and Materials Engineering Faculty Publications

The migration of Li-ions in lithium-ion battery cannot be simply described by Fick's second law; the interactions among ionic migration, field, and stress need to be taken into account when analyzing the migration of Li-ions. Using the theory of thermal activation process, the flux for ionic migration under concurrent action of electric field and mechanical stress is found to be a nonlinear function of the gradient of electric potential and the gradient of stress. Electric field can either accelerate or retard the growth of the lithiation layer, depending on polarity of the field.

Channel Analysis And Estimation And Compensation Of Doppler Shift In Underwater Acoustic Communication And Mitigation Of Ifi, Isi In Ultra-Wideband Radio, Sadia Ahmed

USF Tampa Graduate Theses and Dissertations

Water occupies three fourth of earth's surface. The remaining one fourth is land. Although human habitats reside on land, there is no denying of the vital connection between land and water. The future sustainability of human species on this planet depends on wise utilization of all available resources, including that provided by the vast water world. Therefore, it is imperative to explore, understand, and define this massive, varying, and in many areas, unexplored water domain.

The water domain exploration and data collection can be conducted using manned or unmanned vehicles, as allowed by the water environment. This dissertation addresses three …

Low Cost Infrared And Near Infrared Sensors For Uavs, Samuel T. Aden, James P. Bialas, Zachary Champion, Eugene Levin, Jessica L. Mccarty

Michigan Tech Research Institute Publications

Thermal remote sensing has a wide range of applications, though the extent of its use is inhibited by cost. Robotic and computer components are now widely available to consumers on a scale that makes thermal data a readily accessible resource. In this project, thermal imagery collected via a lightweight remote sensing Unmanned Aerial Vehicle (UAV) was used to create a surface temperature map for the purpose of providing wildland firefighting crews with a cost-effective and time-saving resource. The UAV system proved to be flexible, allowing for customized sensor packages to be designed that could include visible or infrared cameras, GPS, …