Electrical and Computer Engineering Commons^™

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 …

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 …

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.

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 …

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.

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

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

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 …

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.

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

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 …

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 …

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 …

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

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.

Organizational Change, Ann K. Miller

Electrical and Computer Engineering Faculty Research & Creative Works

No abstract provided.

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 …

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.

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.

Dynamic Performance Of Isolated Power Converters, David Badia

Theses

Isolated power converters are primarily used in applications where electrical galvanic isolation is required for safety purposes. They are also used in applications, which require various output voltages level. They have been studied from many different aspects, but in this thesis the fundamental circuits of the flyback, the forward and the half-bridge converters are studied and compared extensively, with regard to their dynamic performance.

This analysis will lead us to a better understanding of their behaviour, that is a crucial point in the selection of each topology for a particular application. Moreover, the dynamic response of each converter is different; …

Analysis And Synthesis Of Primary Side Cycle By Cycle Control Of Isolated Flyback Converters, Radoslaw Nalepa

Theses

This work presents the analysis and design of an isolated flyback converter, without feedback from the load side. The converter is controlled from the primary side using the switch voltage and innovative control circuit topologies.

A detail study of the flyback circuit is undertaken including all known parasitics. Besides the standard parasitics, for example the capacitor resistive effect, other more subtle effects are included in the model development such as inter coil couplingj source capacitance etc. Development of these models has provided information about circuit simplifications without losing accuracy of the model. As a consequence of this model development, it …

Computing A Diameter-Constrained Minimum Spanning Tree, Ayman Mahmoud Abdalla

Retrospective Theses and Dissertations

In numerous practical applications, it is necessary to find the smallest possible tree with a bounded diameter. A diameter-constrained minimum spanning tree (DCMST) of a given undirected, edge-weighted graph, G, is the smallest-weight spanning tree of all spanning trees of G which contain no path with more than k edges, where k is a given positive integer. The problem of finding a DCMST is NP-complete for all values of k; 4 ≤ k ≤ (n - 2), except when all edge-weights are identical.

A DCMST is essential for the efficiency of various distributed mutual exclusion algorithms, where …

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 …

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 …

Multiple-Access Interference Suppression In Cdma Wireless Systems, Jianqiang He

LSU Master's Theses

This thesis presents techniques that suppress the multiple access interference (MAI) in CDMA wireless systems. MAI is the main factor that influences the communication quality and the capacity in CDMA wireless systems. Hence the suppression of MAI is essential to the performance of a CDMA wireless system. For conventional CDMA systems where matched filters are used as receivers, the only MAI suppression method available is the power control, which allocates each user in the system an appropriate transmitter power level such that the transmitter power is minimized to decrease the MAI, while at the same time each user maintains a …

Adaptive Notch Filter For Single And Multiple Narrow-Band Interference, Selina Kuek Lin Mei

Theses : Honours

In this project, the adaptive notch filter for single and Multiple narrow-band interference is implemented using simplified LMS algorithm. Performances of the LMS adaptive algorithms is evaluated and analysed through simulation on the computer using Matlab. The algorithm are then written in C programme and implemented using Texas Instrument Tool which consist of TMS320C54x EMV board and Code Composer Studio.

Fingerprint Recognition Using Neural Networks, Eng Hoe Kennie Yeoh

Student Works (2000-2009)

Traditional methods of fingerprint verification uses either complicated feature detection algorithms that are not specific to each fingerprint, or compare two fingerprint images directly using image processing toots. The former involves very complicated calculations and tedious algorithms, and the latter tend to work poorly. In this paper it is described a new method which takes the middle ground. This paper studies the implementation of the Fast Fourier Transform and Artificial Neural Networks into the recognition of fingerprints. With tests conducted on the implementation of the Fourier Transform as a method of fingerprint feature extraction, the use of the Fourier Transform …

A Noninvasive Test For Vesico-Ureteric Reflux In Children, R. A. Mevorach, B. Cilento, S. Zahorian, C. Badgett, R. Walker, A. Atala, S. Iannello, M. Meyer

Electrical & Computer Engineering Faculty Publications

Objective To report the development and testing of a device for the noninvasive diagnosis of vesico‐ureteric reflux (VUR) which avoids the need for urethral catheterization (currently required to reliably determine the presence of VUR), and which thus avoids the anxiety of parents and patients that causes many families to refuse such evaluation.

Patients and methods Fifty‐four children (49 girls and five boys, mean age 7.2 years, range 4–14) previously evaluated as having VUR volunteered to participate; no child was symptomatic at the time of the study. Refluxing units were known to be present by voiding cysto‐urethrography (within 1 year, mean …

Optical Properties Of Wide Band Gap Indium Sulphide Thin Films Obtained By Physical Vapor Deposition, N. Barreau, S. Marsillac, J. C. Bernède, T. Ben Nasrallah, S. Belgacem

Electrical & Computer Engineering Faculty Publications

Thin films of indium sulphide containing oxygen have been synthesized following a dry physical process. The constituents are deposited by thermal evaporation on glass substrates and then annealed under argon flow. Polycrystalline β-In₂S₃ containing oxygen thin films are obtained as soon as the temperature of annealing is between 623 and 723 K. In this paper, these β-In₂S₃ thin films have optically been studied. The optical band gap is direct. Its value is not dependent on the temperature of annealing. It is about 2.8 eV, which is higher than that of β-In₂S_{3 …}

A New Compensating Element For A Femtosecond Photoelectron Gun, Bao-Liang Qian, Hani E. Elsayed-Ali

Electrical & Computer Engineering Faculty Publications

Design and analysis of a new compensating element for improving the electron pulse front and compressing the pulse duration in a femtosecond photoelectron gun are described. The compensating element is a small metallic cylindrical cavity in which an external voltage is applied in such a way that a special electric field forms and interacts with the electron pulse. This electric field reduces the distances between the faster and slower electrons inside the cavity and efficiently compensates for electron pulse broadening caused by the photoelectron energy spread and space charge effects. Poisson's equation and the equation of motion are solved to …