Electrical and Computer Engineering Commons^™

Laser Plasma Radiation Studies For Droplet Sources In The Extreme Ultraviolet, Reuvani Kamtaprasad

Electronic Theses and Dissertations

The advancement of laboratory based Extreme Ultraviolet (EUV) radiation has escalated with the desire to use EUV as a source for semiconductor device printing. Laser plasmas based on a mass-limited target concept, developed within the Laser Plasma Laboratory demonstrate a much needed versatility for satisfying rigorous source requirements. This concept produces minimal debris concerns and allows for the attainment of high repetition rates as well as the accommodation of various laser and target configurations. This work demonstrates the generation of EUV radiation by creating laser plasmas from mass-limited targets with indium, tin, and antimony doped droplets. Spectral emission from the …

Optimal Control Of Affine Nonlinear Continuous-Time Systems Using An Online Hamilton-Jacobi-Isaacs Formulation, T. Dierks, Sarangapani Jagannathan

Electrical and Computer Engineering Faculty Research & Creative Works

Solving the Hamilton-Jacobi-Isaacs (HJI) equation, commonly used in ℋ∞ optimal control, is often referred to as a two-player differential game where one player tries to minimize the cost function while the other tries to maximize it. in this paper, the HJI equation is formulated online and forward-in-time using a novel single online approximator (SOLA)-Based scheme to achieve optimal regulation and tracking control of affine nonlinear continuous-time systems. the SOLA-Based adaptive approach is designed to learn the infinite horizon HJI equation, the corresponding optimal control input, and the worst-case disturbance. a novel parameter tuning algorithm is derived which not only achieves …

Hardware Implementation Of Triply Selective Rayleigh Fading Channel Simulators, Fei Ren, Yahong Rosa Zheng

Electrical and Computer Engineering Faculty Research & Creative Works

In this paper, we implement a real-time hardware triply selective Rayleigh fading simulator. This simulator incorporates the inter-tap and spatial correlation matrices into multiple uncorrelated frequency-flat Rayleigh fading waveforms (including temporal correlation) to simulate a multiple-input multiple-output (MIMO) triply selective Rayleigh fading channel. in the correlation incorporation procedure, this simulator uses a Kronecker product method to save a large amount of hardware memories. Occupying 34% hardware resources of one Stratix III FPGA chip, this simulator can simulate 4 x 4 MIMO fading channels with 10 correlated delay-taps per subchannel in real-time for a symbol rate of 3.69 μs. Accuracy of …

Decentralized Nearly Optimal Control Of A Class Of Interconnected Nonlinear Discrete-Time Systems By Using Online Hamilton-Bellman-Jacobi Formulation, S. Mehraeen, Sarangapani Jagannathan

Electrical and Computer Engineering Faculty Research & Creative Works

In this paper, the direct neural dynamic programming technique is utilized to solve the Hamilton Jacobi-Bellman (HJB) equation online and forward-in-time for the decentralized nearly optimal control of nonlinear interconnected discrete-time systems in affine form with unknown internal subsystem and interconnection dynamics. Only the state vector of the local subsystem is considered measurable. the decentralized optimal controller design for each subsystem consists of an action neural network (NN) that is aimed to provide a nearly optimal control signal, and a critic NN which approximates the cost function. the NN weights are tuned online for both the NNs. It is shown …

Output Feedback Control Of A Quadrotor Uav Using Neural Networks, Travis Dierks, Sarangapani Jagannathan

Electrical and Computer Engineering Faculty Research & Creative Works

In this paper, a new nonlinear controller for a quadrotor unmanned aerial vehicle (UAV) is proposed using neural networks (NNs) and output feedback. the assumption on the availability of UAV dynamics is not always practical, especially in an outdoor environment. Therefore, in this work, an NN is introduced to learn the complete dynamics of the UAV online, including uncertain nonlinear terms like aerodynamic friction and blade flapping. Although a quadrotor UAV is underactuated, a novel NN virtual control input scheme is proposed which allows all six degrees of freedom (DOF) of the UAV to be controlled using only four control …

Optimal Control Of Affine Nonlinear Continuous-Time Systems, T. Dierks, Sarangapani Jagannathan

Electrical and Computer Engineering Faculty Research & Creative Works

In this paper, the optimal regulation and tracking control of affine nonlinear continuous-time systems with known dynamics is undertaken using a novel single online approximator (SOL)-Based scheme. the SOLA-Based adaptive approach is designed to learn the infinite horizon continuous time Hamilton-Jacobi-Bellman (HJB) equation and its corresponding optimal control input. a novel parameter tuning algorithm is derived which not only ensures the optimal cost (HJB) function and control input are achieved, but also ensures the system states remain bounded during the online learning process. Lyapunov techniques show that all signals are uniformly ultimately bounded (UUB) and the approximated control signal approaches …

A Novel Emulator For Discrete-Time Mimo Triply Selective Fading Channels, Fei Ren, Yahong Rosa Zheng

Electrical and Computer Engineering Faculty Research & Creative Works

Hardware implementation of discrete-time triply selective Rayleigh fading channel emulators is proposed for multiple-input multiple-output (MIMO) communications. the proposed work differs from existing ones in that it incorporates temporal correlation, intertap correlation, and spatial correlation matrices into multiple uncorrelated frequency-flat fading waveforms to obtain a triply selective fading channel. the flat fading waveforms with temporal correlation or Doppler spectrum are generated using a sum-of-sinusoid method. the intertap correlation matrix associated with multipath delay spread is computed according to the channel power delay profile and transmit/receive filters. the spatial correlation matrices are predefined inputs associated with transmit and receive antenna arrangements. …

Crack Detectability And Durability Of Coaxial Cable Sensors In Reinforced Concrete Bridge Applications, Genda Chen, Ryan D. Mcdaniel, Michael A. Brower, David Pommerenke

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

The working mechanism and the measurement principle of topology-based crack sensors made of coaxial cables are briefly reviewed. The sensitivity, spatial resolution, and ruggedness of two coaxial cable sensors, respectively made of rubber and Teflon dielectric materials, were compared and validated with laboratory testing of a 4/5-scale, T-shaped, reinforced concrete beam-column specimen. Two Teflon sensors were installed on one of the solid decks of a three-span continuous highway bridge to investigate their durability and measurement repeatability. Laboratory tests indicated that both types of sensors have high sensitivity, but the Teflon sensor has a higher spatial resolution and a negligible spillover …

An Adaptive Control Strategy For Dstatcom Applications In An Electric Ship Power System, Pinaki Mitra, Ganesh K. Venayagamoorthy

Electrical and Computer Engineering Faculty Research & Creative Works

Distribution static compensator (DSTATCOM) is a shunt compensation device that is generally used to solve power quality problems in distribution systems. In an all-electric ship power system, power quality issues arise due to high-energy demand loads such as pulse loads. This paper presents the application of a DSTATCOM to improve the power quality in a ship power system during and after pulse loads. The control strategy of the DSTATCOM plays an important role in maintaining the voltage at the point of common coupling. A novel adaptive control strategy for the DSTATCOM based on artificial immune system (AIS) is presented in …

Novel Dynamic Representation And Control Of Power Systems With Facts Devices, Shahab Mehraeen, Jagannathan Sarangapani, Mariesa Crow

Electrical and Computer Engineering Faculty Research & Creative Works

FACTS devices have been shown to be useful in damping power system oscillations. However, in large power systems, the FACTS control design is complex due to the combination of differential and algebraic equations required to model the power system. In this paper, a new method to generate a nonlinear dynamic representation of the power network is introduced to enable more sophisticated control design. Once the new representation is obtained, a back stepping methodology for the UPFC is utilized to mitigate the generator oscillations. Finally, the neural network approximation property is utilized to relax the need for knowledge of the power …

Dynamic System Eigenvalue Extraction Using A Linear Echo State Network For Small-Signal Stability Analysis - A Novel Application, Jiaqi Liang, Jing Dai, Ganesh K. Venayagamoorthy, Ronald G. Harley

Electrical and Computer Engineering Faculty Research & Creative Works

A large nonlinear dynamic system usually has complex dynamic modes corresponding to the system's eigenvalues. These eigenvalues govern the system's local behavior and thus are critical information for designing system operation and control strategies. Without the availability of the system's analytical model, which is often the case for large nonlinear systems, the system's eigenvalues need to be estimated. a linear echo state network (ESN) based method for extracting observable eigenvalues of a dynamic system together with the participation factors of these eigenvalues in the accessible system states is presented in this paper. a linear ESN is first trained to track …

On The Power Allocation For Relay Networks With Finite-Alphabet Constraints, Weiliang Zeng, Mingxi Wang, Chengshan Xiao, Jianhua Lu

Electrical and Computer Engineering Faculty Research & Creative Works

In this paper, we investigate the optimal power allocation scheme for relay networks with finite-alphabet constraints. It has been shown that the previous work utilizing various design criteria with the Gaussian inputs assumption may lead to significant loss for a practical system with finite constellation set constraint, especially when signal-to-noise ratio (SNR) is in medium-to-high regions, or when the channel coding rate is medium to high. an optimal power allocation scheme is proposed to maximize the mutual information for the relay networks under discrete-constellation input constraint. Numerical examples show that significant gain can be obtained compared to the conventional counterpart …

Alternative Matching Schemes For Automatic Fingerprint Identification Systems, Michael Jason Futer

Electrical Engineering Theses - Archive

Biometrics is a recognition technology that uses the unique behavioral and physiological traits of the human body as identifiers. The fingerprint is one of the oldest and most widely used forms of biometric identifiers. In this thesis, an automatic fingerprint identification system designed by a previous Electrical Engineering graduate student at The University of Texas at Arlington is upgraded with the purpose of improving matching accuracy. A review of the baseline automatic fingerprint identification system is provided as a reference point for improvements in the system. Then, improvements to the image enhancement stage of the baseline system are discussed. They …

A Ph Sensor Based On A Flexible Substrate, Wen-Ding Huang

Electrical Engineering Dissertations - Archive

pH sensor is an essential component used in many chemical, food, and bio-material industries. Conventional glass electrodes have been used to construct pH sensors, however, have some disadvantages. Glass electrodes are easily affected by alkaline or HF solution, they require a high input impedance pH meter, they often exhibit a sluggish response. In some specific applications, it is also difficult to use glass electrodes for in vivo biomedical or food monitoring applications due to the difficulty of size miniaturization, planarization and polymerization based on current manufacturing technologies. In this work, we have demonstrated a novel flexible pH sensor based on …

Distribution Network Contingency Analysis And Contingency Detection With The Consideration Of Load Models, Qiaohui Hu

Electrical Engineering Dissertations - Archive

The electric utility market environment has changed quite radically during recent years due to the process of deregulation. This has changed the asset management towards a capital controlled business where owners are trying to maximize their profits with cost optimization. To keep up with the increase demands on high reliability and high quality delivery systems, many utilities endeavor to rationalize their system operations with more intelligent control schemes and facilities. A lot of issues under uncertainty such as load growth, quality of supply and environmental impact affect the reliability of the distribution system. Power outage is the most serious challenge …

Nonlinear Dynamic Analysis Of Mitral Valve Doppler Signals: Surrogate Data Analysis, Esma Uzunhi̇sarcikli

Turkish Journal of Electrical Engineering and Computer Sciences

In our study, the nonlinear dynamics of mitral valve Doppler signals from 32 healthy and 28 patients with mitral valve stenosis was evaluated using by the computation of Lyapunov exponents, correlation dimension values and surrogate data analysis. Two chaotic features are compared for healthy and patient subjects. It was found that the largest Lyapunov exponent and correlation dimension values derived from patient subjects were larger than that of healthy subjects (\rho < 0.005). Surrogate data analysis was performed to determine the chaotic dynamics of Doppler signals. It was observed that the original and surrogate data have similar spectral features. Receiver operating characteristic (ROC) curves were used to evaluate the nonlinearity character Area Under the curve (AUC) values were obtained as 0.99 and 0.978 for the largest Lyapunov exponent and correlation dimension values, respectively. According to these results, Doppler signals have a nonlinear dynamic property and the largest Lyapunov exponent. Correlation dimension features can be used to detect the change in blood flow velocity of patients with mitral valve stenosis.

Leakage Current Reduction Of Mos Capacitor Induced By Rapid Thermal Processing, Yichun Wang

University of Kentucky Master's Theses

With the MOSFET scaling practice, the performance of IC devices is improved tremendously as we experienced in the last decades. However, the small semiconductor devices also bring some drawbacks among which the high gate leakage current is becoming increasingly serious.

This thesis work is focused on the of gate leakage current reduction in thin oxide semiconductor devices. The method being studied is the Phonon Energy Coupling Enhancement (PECE) effect induced by Rapid Thermal Processing (RTP). The basic MOS capacitors are used to check improvements of leakage current reduction after appropriate RTP process.

Through sets of experiments, it is found that …

Dual Axis Solar Tracker, Weston Sapia, Jason Birnie

Electrical Engineering

No abstract provided.

Control Strategy For Maximizing Power Conversion Efficiency And Effectiveness Of Three Port Solar Charging Station For Electric Vehicles, Christopher Hamilton

Electronic Theses and Dissertations

Recent trends in the energy sector have provided opportunities in the research of alternative energy sources and optimization of systems that harness these energy sources. With the rising cost of fossil fuel and rising concern about detrimental effects that fossil fuel consumption has on the environment, electric vehicles are becoming more prevalent. A study put out in 2009 gives a prediction that in the year 2025, 20% of new vehicles will be PHEVs.[1] As energy providers become more concerned about a growing population and diminishing energy source, they are looking into alternative energy sources such as wind and solar power. …

Design Of Low-Capacitance And High-Speed Electrostatic Discharge (Esd) Devices For Low-Voltage Protection Applications, You Li

Electronic Theses and Dissertations

Electrostatic discharge (ESD) is defined as the transfer of charge between bodies at different potentials. The electrostatic discharge induced integrated circuit damages occur throughout the whole life of a product from the manufacturing, testing, shipping, handing, to end user operating stages. This is particularly true as microelectronics technology continues shrink to nano-metric dimensions. The ESD related failures is a major IC reliability concern and results in a loss of millions dollars to the semiconductor industry each year. Several ESD stress models and test methods have been developed to reproduce the real world ESD discharge events and quantify the sensitivity of …