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Electrical and Computer Engineering Faculty Research & Creative Works

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Power Quality, Badrul H. Chowdhury Jan 2001

Power Quality, Badrul H. Chowdhury

Electrical and Computer Engineering Faculty Research & Creative Works

One big reason for the poor power quality incidents experienced today is the proliferation of electronic devices. A voracious appetite for higher efficiency and productivity in the manufacturing sector, comfort and automation in homes, and efficient lighting systems in commercial installations are driving the market for power electronic devices. At the forefront of this explosion is the switched power supply. Compared to its predecessor-the linear power supply-it can convert higher power much more efficiently and with a significantly smaller footprint. The switched power supply is found in most of today''s computers, fax machines, laser printers, office copiers, etc.

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Multi-Level Voltage-Source Duty-Cycle Modulation: Analysis And Implementation, Keith Corzine, J. R. Baker Jan 2001

Multi-Level Voltage-Source Duty-Cycle Modulation: Analysis And Implementation, Keith Corzine, J. R. Baker

Electrical and Computer Engineering Faculty Research & Creative Works

Multi-level converters have become increasingly popular due to high power quality, high-voltage capability, low switching losses, and low EMC concerns. Considering these advantages, the multi-level converter is a suitable candidate for implementation of future naval ship propulsion systems. This paper focuses on modulation techniques for the multi-level converter. In particular, a novel voltage-source method of multi-level modulation is introduced and compared to existing methods. The proposed method is discrete in nature and can therefore be readily implemented on a digital signal processor (DSP). The method is also readily extendable to any number of voltage levels. Results of experimental implementation are …

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Volume Management In San Environment, Chang-Soo Kim, Gyoung-Bae Kim, Bum-Joo Shin Jan 2001

Volume Management In San Environment, Chang-Soo Kim, Gyoung-Bae Kim, Bum-Joo Shin

Electrical and Computer Engineering Faculty Research & Creative Works

Logical volume managers have long been key components of a storage system. Their key features are creation of logical or virtual views of physical storage devices and support for various software RAID levels. These make it possible to overcome the limits to capacity, availability and performance of a physical storage device. Most logical volume managers are operated in a single system environment. They are not adequate for SAN (storage area network) environments where several hosts share and access a logical volume at the same time. Some recent logical volume managers are run in a multi-host environment. However, they cannot support …

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Detection And Classification Of Impact-Induced Damage In Composite Plates Using Neural Networks, Rohit Dua, Steve Eugene Watkins, Donald C. Wunsch, K. Chandrashekhara, Farhad Akhavan Jan 2001

Detection And Classification Of Impact-Induced Damage In Composite Plates Using Neural Networks, Rohit Dua, Steve Eugene Watkins, Donald C. Wunsch, K. Chandrashekhara, Farhad Akhavan

Electrical and Computer Engineering Faculty Research & Creative Works

Artificial neutral networks (ANN) can be used as an online health monitoring systems (involving damage assessment, fatigue monitoring and delamination detection) for composite structures owing to their inherent fast computing speeds, parallel processing and ability to learn and adapt to the experimental data. The amount of impact-induced strain on a composite structure can be found using strain sensors attached to composite structures. Prior work has shown that strain-based ANN can characterize impact energy on composite plates and that strain signatures can be associated with damage types and severity. This paper reports the extension of this approach for damage classification using …

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Dynamic Resource Allocation For Network Echo Cancellation, T. Gansler, J. Benesty, M. Mohan Sondhi, Steven L. Grant Jan 2001

Dynamic Resource Allocation For Network Echo Cancellation, T. Gansler, J. Benesty, M. Mohan Sondhi, Steven L. Grant

Electrical and Computer Engineering Faculty Research & Creative Works

Network echo canceler chips are designed to handle several channels simultaneously. With the processing speeds now available, a single chip might handle several hundred channels. In current implementations, however, the adaptation algorithm is designed for a single channel, and the computations are replicated N c times, where N c is the number of channels. With such an implementation, the computational requirement is N c times the peak load for a single channel. The number of computations required in each channel, however, varies widely over time. Therefore, a considerable reduction in computational load can be achieved by designing the system for …

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Estimation Of Printed Circuit Board Power Bus Noise At Resonance Using A Simple Transmission Line Model, H. Hu, Todd H. Hubing, Thomas Van Doren Jan 2001

Estimation Of Printed Circuit Board Power Bus Noise At Resonance Using A Simple Transmission Line Model, H. Hu, Todd H. Hubing, Thomas Van Doren

Electrical and Computer Engineering Faculty Research & Creative Works

The maximum coupling between printed circuit board components connected to the same power-ground plane pair often occurs at or near power bus resonances. Theoretically, the transfer coefficient, S 21 , between two locations on the power bus can be as high as 0dB (i.e. perfect coupling) near resonant frequencies. However, in practice the coupling is usually much less due to losses in the power bus structure. Determining exactly what the maximum coupling will be in a lossy power bus structure requires a numerical model or measurement. However, an estimation of the maximum coupling can be obtained by drawing an analogy …

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High-Power Microwave Wideband Random Signal Measurement And Narrowband Signal Detection Against The Noise Background, Marina Koledintseva, Alexander A. Kitaytsev, V. A. Konkin Jan 2001

High-Power Microwave Wideband Random Signal Measurement And Narrowband Signal Detection Against The Noise Background, Marina Koledintseva, Alexander A. Kitaytsev, V. A. Konkin

Electrical and Computer Engineering Faculty Research & Creative Works

A method of both measurement of power parameters of a microwave wideband intense random signal and detection of a narrow-band signal with unknown frequency and power against a background of this wideband signal is presented. This method is based on nonheterodyne frequency and power conversion using a gyromagnetic converter that operates in two regimes: resonance detection and cross-multiplication. The wideband spectrum envelope of a random signal is visualized, and by switching two regimes and using correspondent filtration of the converted RF signal, the narrowband signals can be detected and measured. The block-scheme and operation of a two-channel measuring device combining …

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Measurement And Monitoring Of Microwave Reflection And Transmission Properties Of Cement-Based Materials For Propagation Modeling, Sergey Kharkovsky, U. C. Hasar, M. F. Akay, C. D. Atis Jan 2001

Measurement And Monitoring Of Microwave Reflection And Transmission Properties Of Cement-Based Materials For Propagation Modeling, Sergey Kharkovsky, U. C. Hasar, M. F. Akay, C. D. Atis

Electrical and Computer Engineering Faculty Research & Creative Works

A non-destructive, contactless, free-space method is used for measuring and monitoring the properties of cement-based materials. We analyse the propagation factor, penetration depth and reflection and transmission coefficients of the plane wave interacting with the highly lossy specimen. Results are presented of the measurement and monitoring of the properties of cement-based materials during all stages of their lives and different curing conditions The expected applications of the results for propagation modelling are discussed.

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The Design And Analysis Of An Analog Ratio Spectrum Circuit, Liping Deng, John G. Harris Jan 2001

The Design And Analysis Of An Analog Ratio Spectrum Circuit, Liping Deng, John G. Harris

Electrical and Computer Engineering Faculty Research & Creative Works

The ratio spectrum (RS) is a novel method for signal analysis that has been successfully demonstrated for speech recognition and coding applications. In this paper, an improved RS circuit with an adaptive tenth-order Butterworth low-pass filter has been designed. We also present the first convergence analysis of the ratio spectrum. We derive linearized convergence expressions for the RS and compare the theoretical predictions to circuit simulations. © 2001 IEEE.

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Factory Automation: A Controls Course For Every University, Kelvin T. Erickson Jan 2001

Factory Automation: A Controls Course For Every University, Kelvin T. Erickson

Electrical and Computer Engineering Faculty Research & Creative Works

The majority of new control engineering positions is now in manufacturing and involves programmable logic controllers (PLCs). The paper describes two courses developed at the University of Missouri-Rolla to satisfy this demand. Both courses present the subject of programming PLCs with an emphasis on the design of the programs. Both courses contain an integral laboratory component that solidifies the concepts presented in the lectures. The philosophy and pedagogical features of the two courses are first described, followed by the structure of the lecture and the laboratory exercises.

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Analysis Of A Four-Level Dc/Dc Buck Converter, Keith Corzine, J. Yuen, J. R. Baker Jan 2001

Analysis Of A Four-Level Dc/Dc Buck Converter, Keith Corzine, J. Yuen, J. R. Baker

Electrical and Computer Engineering Faculty Research & Creative Works

In this paper, a four-level DC/DC buck converter is introduced. The primary application for this converter is to regulate the center capacitor voltage in a four-level inverter system. The steady-state and average-value models for the proposed converter are developed and compared in simulation. The converter was constructed in the laboratory and verified on a four-level motor drive system. It was shown that the four-level DC/DC converter provides capacitor voltage balancing and allows higher output voltage utilization from the inverter.

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A Continually Online Trained Neurocontroller For Excitation And Turbine Control Of A Turbogenerator, Ganesh K. Venayagamoorthy, Ronald G. Harley Jan 2001

A Continually Online Trained Neurocontroller For Excitation And Turbine Control Of A Turbogenerator, Ganesh K. Venayagamoorthy, Ronald G. Harley

Electrical and Computer Engineering Faculty Research & Creative Works

No abstract provided.

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A Statistical Solution To A Text Decoding Challenge Problem, Xindi Cai, Rui Xu, Donald C. Wunsch, V. A. Samaranayake Jan 2001

A Statistical Solution To A Text Decoding Challenge Problem, Xindi Cai, Rui Xu, Donald C. Wunsch, V. A. Samaranayake

Electrical and Computer Engineering Faculty Research & Creative Works

Given an encoded unknown text message in the form of a three dimensional spatial series generated by the use of four smooth nonlinear functions, we use a method based on simple statistical reasoning to pick up samples for rebuilding the four functions. The estimated functions are then used to decode the sequence. The experimental results show that our method gives a nearly perfect decoding, enabling us to submit a 100% accurate solution to the IJCNN challenge problem

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20-H Rule Modeling And Measurements, Todd H. Hubing, Hwan-Woo Shim Jan 2001

20-H Rule Modeling And Measurements, Todd H. Hubing, Hwan-Woo Shim

Electrical and Computer Engineering Faculty Research & Creative Works

The 20-H rule is a printed circuit board layout guideline. On boards with power and ground planes, the fringing field at the edges of the board is contained by backing the edge of the power plane away from the edge of the board by a distance equal to 20 times the separation distance between the planes. In this study, test boards were built and measured with and without implementing the 20-H rule. The measured results are compared to numerical models. The results of this study show that, although the near fields are more contained, the radiation from a board implementing …

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A Novel Morphological Operator To Calculate Euler Number, Zhao Zhang, Randy Hays Moss, William V. Stoecker Jan 2001

A Novel Morphological Operator To Calculate Euler Number, Zhao Zhang, Randy Hays Moss, William V. Stoecker

Electrical and Computer Engineering Faculty Research & Creative Works

This paper introduces a novel morphological operator to calculate the Euler number for binary images. The operator is based on the condition of eight-connectedness for foreground and four-connectedness for background. It is significantly faster than the previous operators. The morphological operations used in border detection are discussed

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A Parallel Computer-Go Player, Using Hdp Method, Donald C. Wunsch, Xindi Cai Jan 2001

A Parallel Computer-Go Player, Using Hdp Method, Donald C. Wunsch, Xindi Cai

Electrical and Computer Engineering Faculty Research & Creative Works

The game of Go has simple rules to learn but requires complex strategies to play well, and, the conventional tree search algorithm for computer games is not suited for Go program. Thus, the game of Go is an ideal problem domain for machine learning algorithms. This paper examines the performance of a 19x19 computer Go player, using heuristic dynamic programming (HDP) and parallel alpha-beta search. The neural network based Go player learns good Go evaluation functions and wins about 30% of the games in a test series on 19x19 board

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Numerical Modelling Of Whispering Gallery Modes In Parallel-Plates Type Cylindrical Anisotropic Dielectric Resonators, Yu Prokopenko, Sergey Kharkovsky, M. F. Akay Jan 2001

Numerical Modelling Of Whispering Gallery Modes In Parallel-Plates Type Cylindrical Anisotropic Dielectric Resonators, Yu Prokopenko, Sergey Kharkovsky, M. F. Akay

Electrical and Computer Engineering Faculty Research & Creative Works

A parallel-plates-type cylindrical anisotropic dielectric resonator (DR) with whispering gallery modes (WGMs) has been investigated. Numerical modelling of the resonance frequencies, Q-factors and the electric field filling factors of the isotropic and anisotropic DR are presented. Applications of the results for sensing purposes are discussed.

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Organizational Change, Ann K. Miller Jan 2001

Organizational Change, Ann K. Miller

Electrical and Computer Engineering Faculty Research & Creative Works

No abstract provided.

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Robust Control Of Input Limited Smart Structural Systems, Sridhar Sana, Vittal S. Rao Jan 2001

Robust Control Of Input Limited Smart Structural Systems, Sridhar Sana, Vittal S. Rao

Electrical and Computer Engineering Faculty Research & Creative Works

Integration of controllers with smart structural systems require the controllers to consume less power and to be small in hardware size. These requirements pose as limits on the control input and the order of the controllers. Use of reduced order model of the plant in the controller design can cause spill over problems in the closed-loop system due to possible excitation of the unmodeled dynamics. In this paper, we present a method to design output feedback robust controllers for smart structures in the presence of control input limits considering unmodeled dynamics as additive uncertainty in the design. The performance requirements …

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Challenge Problem Update: Peec And Mom Analysis Of A Pc Board With Long Wires Attached, H. Wang, Todd H. Hubing, Bruce Archambeault Jan 2001

Challenge Problem Update: Peec And Mom Analysis Of A Pc Board With Long Wires Attached, H. Wang, Todd H. Hubing, Bruce Archambeault

Electrical and Computer Engineering Faculty Research & Creative Works

At the 2000 IEEE International Symposium on EMC, a paper was presented by Y. Ji et al. (paper appears in 2001 proceedings) that compared the application of PEEC and MOM techniques to the analysis of one of the EMC Society/Applied Computational Electromagnetics Society special challenge problems. Good agreement was obtained between the two codes at 2 out of the 3 measurement ports. At that time, no definite explanation was provided for the discrepancy at the third port. This paper shows that the problem was (at least partly) related to assumptions made about the signal source

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Dynamic Re-Optimization Of A Fed-Batch Fermentor Using Adaptive Critic Designs, Donald C. Wunsch, M. S. Iyer Jan 2001

Dynamic Re-Optimization Of A Fed-Batch Fermentor Using Adaptive Critic Designs, Donald C. Wunsch, M. S. Iyer

Electrical and Computer Engineering Faculty Research & Creative Works

Traditionally, fed-batch biochemical process optimization and control uses complicated off-line optimizers, with no online model adaptation or re-optimization. This study demonstrates the applicability of a class of adaptive critic designs for online re-optimization and control of an aerobic fed-batch fermentor. Specifically, the performance of an entire class of adaptive critic designs, viz., heuristic dynamic programming, dual heuristic programming and generalized dual heuristic programming, was demonstrated to be superior to that of a heuristic random optimizer, on optimization of a fed-batch fermentor operation producing monoclonal antibodies

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Dual Heuristic Programming Excitation Neurocontrol For Generators In A Multimachine Power System, Ganesh K. Venayagamoorthy, Donald C. Wunsch, Ronald G. Harley Jan 2001

Dual Heuristic Programming Excitation Neurocontrol For Generators In A Multimachine Power System, Ganesh K. Venayagamoorthy, Donald C. Wunsch, Ronald G. Harley

Electrical and Computer Engineering Faculty Research & Creative Works

The design of optimal neurocontrollers that replace the conventional automatic voltage regulators for excitation control of turbogenerators in a multimachine power system is presented in this paper. The neurocontroller design is based on dual heuristic programming (DHP), a powerful adaptive critic technique. The feedback variables are completely based on local measurements from the generators. Simulations on a three-machine power system demonstrate that DHP based neurocontrol is much more effective than the conventional PID control for improving dynamic performance and stability of the power grid under small and large disturbances. This paper also shows how to design optimal multiple neurocontrollers for …

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Experimental Studies With Continually Online Trained Artificial Neural Network Identifiers For Multiple Turbogenerators On The Electric Power Grid, Ganesh K. Venayagamoorthy, Donald C. Wunsch, Ronald G. Harley Jan 2001

Experimental Studies With Continually Online Trained Artificial Neural Network Identifiers For Multiple Turbogenerators On The Electric Power Grid, Ganesh K. Venayagamoorthy, Donald C. Wunsch, Ronald G. Harley

Electrical and Computer Engineering Faculty Research & Creative Works

The increasing complexity of a modern power grid highlights the need for advanced system identification techniques for effective control of power systems. This paper provides a new method for nonlinear identification of turbogenerators in a 3-machine 6-bus power system using online trained feedforward neural networks. Each turbogenerator in the power system is equipped with a neuro-identifier, which is able to identify its particular turbogenerator and the rest of the network to which it is connected from moment to moment, based on only local measurements. Each neuro-identifier can then be used in the design of a nonlinear neurocontroller for each turbogenerator …

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Reduced Parts-Count Multi-Level Rectifiers, Keith Corzine, J. Yuen, J. R. Baker Jan 2001

Reduced Parts-Count Multi-Level Rectifiers, Keith Corzine, J. Yuen, J. R. Baker

Electrical and Computer Engineering Faculty Research & Creative Works

Multi-level power converters have gained much attention due to their high power quality, low switching losses, and high-voltage capability. These advantages make the multi-level converter a candidate topology for the next generation of naval ship propulsion systems. The primary disadvantage of these systems is the large number of semiconductors involved. This paper presents a reduced parts-count rectifier which is well suited for naval rectifier applications where bi-directional power flow is not required. The proposed converter is analyzed and experimentally verified on an 18 kW four-level rectifier/inverter system.

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Reducing Power Bus Impedance At Resonance With Lossy Components, Todd H. Hubing, Theodore M. Zeeff Jan 2001

Reducing Power Bus Impedance At Resonance With Lossy Components, Todd H. Hubing, Theodore M. Zeeff

Electrical and Computer Engineering Faculty Research & Creative Works

Power bus structures in printed circuit boards with solid power and ground planes exhibit resonances. When the power bus is resonant, the power bus impedance can increase dramatically. This paper explores the effect of component equivalent series resistance (ESR) on power bus resonances. General guidelines for selecting an optimum ESR are provided and are supported by laboratory measurements and numerical simulations

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Design And Implementation Of A Biologically Realistic Olfactory Cortex In Analog Vlsi, Jose C. Principe, Vitor G. Tavares, John G. Harris, Walter J. Freeman Jan 2001

Design And Implementation Of A Biologically Realistic Olfactory Cortex In Analog Vlsi, Jose C. Principe, Vitor G. Tavares, John G. Harris, Walter J. Freeman

Electrical and Computer Engineering Faculty Research & Creative Works

This paper reviews the problem of translating signals into symbols preserving maximally the information contained in the signal time structure. In this context, we motivate the use of nonconvergent dynamics for the signal to symbol translator. We then describe a biologically realistic model of the olfactory system proposed by Walter Freeman that has locally stable dynamics but is globally chaotic. We show how we can discretize Freemans model using digital signal processing techniques, providing an alternative to the more conventional Runge-Kutta integration. This analysis leads to a direct mixed signal {analog amplitude/discrete time) implementation of the dynamical building block that …

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Computer Viruses, S. R. Subramanya, Natraj Lakshminarasmhan Jan 2001

Computer Viruses, S. R. Subramanya, Natraj Lakshminarasmhan

Electrical and Computer Engineering Faculty Research & Creative Works

No abstract provided.

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A Fast Evanescent Wave Algorithm, W. C. Chew, L. (Lijun) J. Jiang, S. Velamparambil Jan 2001

A Fast Evanescent Wave Algorithm, W. C. Chew, L. (Lijun) J. Jiang, S. Velamparambil

Electrical and Computer Engineering Faculty Research & Creative Works

Description of a fast evanescent wave algorithm was presented that traded off the use of memory for increasing the speed. The use of the buffer boxes was avoided by the algorithm which increased its speed. An efficient method to derive or store the evanescent wave spectrum from the propagating wave spectrum was studied.

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A Nonlinear Voltage Controller With Derivative Adaptive Critics For Multimachine Power Systems, Ganesh K. Venayagamoorthy, Donald C. Wunsch, Ronald G. Harley Jan 2001

A Nonlinear Voltage Controller With Derivative Adaptive Critics For Multimachine Power Systems, Ganesh K. Venayagamoorthy, Donald C. Wunsch, Ronald G. Harley

Electrical and Computer Engineering Faculty Research & Creative Works

Based on derivative adaptive critics, a novel nonlinear optimal voltage/excitation control for a multimachine power system is presented. The feedback variables are completely based on local measurements. Simulations on a three-machine system demonstrate that the nonlinear controller is much more effective than the conventional PID controller equipped with a power system stabilizer for improving dynamic performance and stability under small and large disturbances.

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Millimeter Wave Oscillator Based Dielectric Hemisphere With Cylinder Shield, Sergey Kharkovsky, A. E. Kogut, V. V. Kutuzov Jan 2001

Millimeter Wave Oscillator Based Dielectric Hemisphere With Cylinder Shield, Sergey Kharkovsky, A. E. Kogut, V. V. Kutuzov

Electrical and Computer Engineering Faculty Research & Creative Works

The purpose of this paper is the investigation of the main Gunn diode oscillator characteristics with a hemispherical dielectric resonator which is shielded by a metal cylinder. The frequency, output power and electronic tuning of frequency, the steepness of which allows one to estimate the frequency stability in relation to the parasitic change of the Gunn diode voltage, and their comparative analysis with the characteristics of generation in a similar open dielectric resonator.

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