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Electrical and Computer Engineering Faculty Research & Creative Works

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Full-Text Articles in Engineering

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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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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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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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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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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Art/Sofm: A Hybrid Approach To The Tsp, Narayan Vishwanathan, Donald C. Wunsch Jan 2001

Art/Sofm: A Hybrid Approach To The Tsp, Narayan Vishwanathan, Donald C. Wunsch

Electrical and Computer Engineering Faculty Research & Creative Works

We present a new method of solving large scale travelling salesman problem (TSP) instances using a combination of adaptive resonance theory (ART) and self organizing feature maps (SOFM). We divide our algorithm into three phases: phase one uses ART to form clusters of cities; phase two uses a novel modification of the traditional SOFM algorithm to solve a slight variant of the TSP in each cluster of cities; and phase three uses another version of the SOFM to link all the clusters. The experimental results show that our algorithm finds approximate solutions which are about 13% longer than those reported …

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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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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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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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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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Whispering Gallery Mode Dielectric Resonators For The Millimeter Wave Near Field Sensing Applications, Sergey Kharkovsky, Yu Prokopenko, M. F. Akay Jan 2001

Whispering Gallery Mode Dielectric Resonators For The Millimeter Wave Near Field Sensing Applications, Sergey Kharkovsky, Yu Prokopenko, M. F. Akay

Electrical and Computer Engineering Faculty Research & Creative Works

The resonance characteristics of whispering gallery modes (WGMs) in parallel-plate type cylindrical dielectric resonators (DRs) are numerically considered to optimise their characteristics for sensing applications. Results for the dependency of the resonant frequency, Q-factor, slow-down factor and electric energy filling factor of the modes on resonator parameters for both isotropic and anisotropic DR are presented. The possible applications of the results for millimeter wave near field nondestructive measurements 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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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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Experiments On Adaptive Techniques For Host-Based Intrusion Detection, Timothy Draelos, Michael Collins, David Duggan, Edward Thomas, Donald C. Wunsch Jan 2001

Experiments On Adaptive Techniques For Host-Based Intrusion Detection, Timothy Draelos, Michael Collins, David Duggan, Edward Thomas, Donald C. Wunsch

Electrical and Computer Engineering Faculty Research & Creative Works

This research explores four experiments of adaptive host-based intrusion detection (ID) techniques in an attempt to develop systems that can detect novel exploits. The technique considered to have the most potential is adaptive critic designs (ACDs) because of their utilization of reinforcement learning, which allows learning exploits that are difficult to pinpoint in sensor data. Preliminary results of ID using an ACD, an Elman recurrent neural network, and a statistical anomaly detection technique demonstrate an ability to learn to distinguish between clean and exploit data. We used the Solaris Basic Security Module (BSM) as a data source and performed considerable …

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Excitation And Turbine Neurocontrol With Derivative Adaptive Critics Of Multiple Generators On The Power Grid, Ganesh K. Venayagamoorthy, Donald C. Wunsch, Ronald G. Harley Jan 2001

Excitation And Turbine Neurocontrol With Derivative Adaptive Critics Of Multiple Generators On The Power Grid, Ganesh K. Venayagamoorthy, Donald C. Wunsch, Ronald G. Harley

Electrical and Computer Engineering Faculty Research & Creative Works

Based on derivative adaptive critics, neurocontrollers for excitation and turbine control of multiple generators on the electric power grid are presented. The feedback variables are completely based on local measurements. Simulations on a three-machine power system demonstrate that the neurocontrollers are much more effective than conventional PID controllers, the automatic voltage regulators and the governors, for improving the dynamic performance and stability under small and large disturbances

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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 Specimens, Sergey Kharkovsky, M. F. Akay, U. C. Hasar, C. D. Atis Jan 2001

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

Electrical and Computer Engineering Faculty Research & Creative Works

The results of measurement and monitoring of reflection and transmission properties of cement-based specimens (blocks of mortar, concrete) during long time of their service lives, including hydration process, and different curing conditions at microwave frequencies (X-band) are presented. A simple and inexpensive measurement system that utilizes the nondestructive and contactless free space method is used. Dependencies of the reflection and transmission coefficients on water-to-cement ratio, preparing and curing conditions of the specimens are demonstrated. It is shown that the reflection coefficient is approximately stable after hydration process while the transmission coefficient changes during long time of the specimen''s service life. …

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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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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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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 Committee Of Neural Networks For Automatic Speaker Recognition (Asr) Systems, Viresh Moonasar, Ganesh K. Venayagamoorthy Jan 2001

A Committee Of Neural Networks For Automatic Speaker Recognition (Asr) Systems, Viresh Moonasar, Ganesh K. Venayagamoorthy

Electrical and Computer Engineering Faculty Research & Creative Works

This paper describes how the results of speaker verification systems can be improved and made robust with the use of a committee of neural networks for pattern recognition rather than the conventional single-network decision system. It illustrates the use of a supervised learning vector quantization neural network as the pattern classifier. Linear predictive coding and cepstral signal processing techniques are utilized to form hybrid feature parameter vectors to combat the effect of decreased recognition success with increased group size (number of speakers to be recognized)

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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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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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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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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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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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