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2008

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Articles 1 - 30 of 911

Full-Text Articles in Electrical and Computer Engineering

Ensemble Of Classifiers Based Data Fusion Of Eeg And Mri For Diagnosis Of Neurodegenerative Disorders, Tejash Patel Dec 2008

Ensemble Of Classifiers Based Data Fusion Of Eeg And Mri For Diagnosis Of Neurodegenerative Disorders, Tejash Patel

Theses and Dissertations

The prevalence of Alzheimer's disease (AD), Parkinson's disease (PD), and mild cognitive impairment (MCI) are rising at an alarming rate as the average age of the population increases, especially in developing nations. The efficacy of the new medical treatments critically depends on the ability to diagnose these diseases at the earliest stages. To facilitate the availability of early diagnosis in community hospitals, an accurate, inexpensive, and noninvasive diagnostic tool must be made available. As biomarkers, the event related potentials (ERP) of the electroencephalogram (EEG) - which has previously shown promise in automated diagnosis - in addition to volumetric magnetic resonance …


Exploration Of Multiple Pathways For The Development Of Immersive Virtual Reality Environments, Kevin Laurence Garrison Dec 2008

Exploration Of Multiple Pathways For The Development Of Immersive Virtual Reality Environments, Kevin Laurence Garrison

Theses and Dissertations

The focus of this thesis is the study and recommendation of optimal techniques for developing immersive virtual environments for generic applications. The overarching objective is to ensure that virtual environments can be created and deployed, rapidly and accurately, using commercial off-the-shelf software. Specific subjective and objective criteria have been employed to determine trade-offs between multiple pathways for designing such environments and specific recommendations are made for the applicability of each. The efficacy of the techniques developed as part of this research work has been demonstrated by applying them to three widely differing areas - visualizing arbitrary 2D surface data, synthesis …


Data Fusion Based Optimal Eeg Electrode Selection For Early Diagnosis Of Alzheimer's Disease, Brian Balut Dec 2008

Data Fusion Based Optimal Eeg Electrode Selection For Early Diagnosis Of Alzheimer's Disease, Brian Balut

Theses and Dissertations

As medicinal and technological advances lengthen the average human life span, diseases affecting the elderly such as Alzheimer's disease and Parkinson's disease are seeing increasingly growing numbers, especially in developed countries. As a result, the necessity for an accurate, inexpensive, noninvasive means of diagnosis becomes particularly important, since such a method is not readily available to the general population. One biomarker that has recently showed promise is the analysis of the electroencephalogram (EEG).

Over the course of two studies, more than 130 subjects have been recruited providing information from 16-19 EEG electrodes for each subject. These signals have been decomposed …


Use Of Linear Predictive Features And Pattern Recognition Techniques To Develop A Vector Quantization Based Blind Snr Estimation System, Russell Paul Ondusko Iii Dec 2008

Use Of Linear Predictive Features And Pattern Recognition Techniques To Develop A Vector Quantization Based Blind Snr Estimation System, Russell Paul Ondusko Iii

Theses and Dissertations

Signal-to-noise ratio is defined as the ratio of a given transmitted signal to the background noise of the transmission medium. Signal-to-noise ratio (SNR) is a common concept found in all forms of electrical communications. The easiest way to measure the signal-to-noise ratio is through intrusive means in which a corrupt signal is compared to its original signal. This technique is inefficient and impractical because it requires the original signal and can only be used to theoretically test the noise properties of a channel rather than estimate the SNR of a communicated signal. Characteristics of speech signals can be used to …


Quad General Tree Drawing Algorithm And General Trees Characterization: Towards An Environment For The Experimental Study On General Tree Drawing Algorithms, Chu Yao Dec 2008

Quad General Tree Drawing Algorithm And General Trees Characterization: Towards An Environment For The Experimental Study On General Tree Drawing Algorithms, Chu Yao

Theses and Dissertations

Information visualization produces (interactive) visual representations of abstract data to reinforce human cognition and perception; thus enabling the viewer to gain knowledge about the internal structure of the data and causal relationships in it. The visualization of information hierarchies is concerned with the presentation of abstract hierarchical information about relationships between various entities. It has many applications in diverse domains such as software engineering, information systems, biology, and chemistry. Information hierarchies are typically modeled by an abstract tree, where vertices are entities and edges represent relationships between entities. The aim of visualizing tree drawings is to automatically produce drawings of …


Thermal Modeling Of On-Chip Interconnects And 3d Packaging Using Em Tools, Lijun Jiang, Seshadri Kolluri, Barry J. Rubin, Howard Smith, Evan G. Colgan, Michael R. Scheuermann, Jamil A. Wakit, Alina Deutsch, Jason Gill Dec 2008

Thermal Modeling Of On-Chip Interconnects And 3d Packaging Using Em Tools, Lijun Jiang, Seshadri Kolluri, Barry J. Rubin, Howard Smith, Evan G. Colgan, Michael R. Scheuermann, Jamil A. Wakit, Alina Deutsch, Jason Gill

Electrical and Computer Engineering Faculty Research & Creative Works

The green (low power) chip design demands dramatic thermal and electrical simulation capabilities. In this paper, a novel thermal simulation approach for automatic thermal modeling of very large problems is introduced. This methodology can be fully integrated with existing solvers for electrical simulations, and make it possible to analyze practical on-chip and packaging thermal problems using the existing electromagnetic tools and geometry definitions, with very small additional effort. Its various applications to BEOL (on-chip wiring), thermal guideline design, and 3D integration (for multiple chip stacks) thermal modeling are investigated in this paper. We will demonstrate this capability with an automatic …


Design And Development Of A Prototype For A Web-Based Interface For Online Material For Tanzanian Youth, Mjema A.M Dec 2008

Design And Development Of A Prototype For A Web-Based Interface For Online Material For Tanzanian Youth, Mjema A.M

Tanzania Journal of Engineering and Technology (TJET)

A prototype of a web-based interface for an online database was developed to be used by youth organizations in Dar-es-Salaam. A participatory approach involving secondary students in the identification of user interface requirements, in designing and testing the prototype was used. A questionnaire was designed and manned in seven secondary schools in Dar-es-Salaam to estimate the Internet usage. Interviews were conducted to countercheck the questionnaire responses. The interview and the questionnaire helped to come up with a set of user requirements for the web-based interface of an online information search. From the specifications of the user requirements the author was …


The Systemic Nature Of Action Learning Programmes, G Mwaluko Dec 2008

The Systemic Nature Of Action Learning Programmes, G Mwaluko

Tanzania Journal of Engineering and Technology (TJET)

A lot of attention has been paid on action learning in the last four decades or so and the success of such programmes has also been widely publicized. But why have these programmes been so effective in helping organizations cope with change? Many authors state that the success of such programmes is due to the fact that they link learning to actions. Yet others claim that action learning programmes succeed because they involve employee empowerment and provide a much greater learning curve. In this paper the authors hold that action learning programmes succeed because they are partly systemic and can …


Analytical Modeling Of A Large Local Area Network - Part I: Internet Traffic Characterization, Mathew Luhanga Dec 2008

Analytical Modeling Of A Large Local Area Network - Part I: Internet Traffic Characterization, Mathew Luhanga

Tanzania Journal of Engineering and Technology (TJET)

The goal of both IP network operators and the end users is to get the highest performance from the system for a given cost. This makes Performance a key criterion in the design, procurement, and use of computer and communication systems. In order to address problems associated with performance degradation of operational communications systems, over the last decade, traffic engineering techniques have emerged in an attempt to optimize communication systems’ performance and ensure more efficient use of their resources. One of these techniques is analytical modeling. Analytic performance models are an excellent tool for quickly evaluating the performance of operational …


Methods And Apparatus For Preventing A Third Party From Overhearing A Telephone Conversation, Thaddeus Gabara, Vladimir I. Prodanov Dec 2008

Methods And Apparatus For Preventing A Third Party From Overhearing A Telephone Conversation, Thaddeus Gabara, Vladimir I. Prodanov

Electrical Engineering

Methods and apparatus are provided for preventing a third party from listening to a conversation between at least two participants on a telephone. The telephone generates an audio stimulus signal that is presented through a secondary speaker. The audio stimulus signal may be, for example, pseudorandom noise or a cancellation signal. According to one aspect of the invention, the telephone ensures that the audio stimulus signal does not significantly impair the conversation for the at least two participants. To prevent the third party from listening to the local portion of the conversation, the audio stimulus signal is subtracted from the …


Grey Measurement Based On Rough Set Granule Calculations, Jian Liu, Zhili Huang, Shunxiang Wu, Ruiyi Chen Dec 2008

Grey Measurement Based On Rough Set Granule Calculations, Jian Liu, Zhili Huang, Shunxiang Wu, Ruiyi Chen

Electrical and Computer Engineering Faculty Research & Creative Works

This paper put the Rough set methodology based on the information table disposal to expand the dual (binary) relations described by the neighborhood system. To make full use of logic operations including AND operation by-bit, XOR operation by-bit and NOR operation by-bit, gains the certain and uncertain information among the various decision-making factors. The use of knowledge related with Grey system theory, establishes their mathematical model for decision making and data mining, according to the principle of the priority of certain information in decision-making and the ambiguity degree from small to big. At last, a new method for data mining …


Secondary Electron Imaging Of Embedded Defects In Carbon Nanofiber Via Interconnects, Makoto Suzuki, Yusuke Ominami, Takashi Sekiguchi, Cary Y. Yang Dec 2008

Secondary Electron Imaging Of Embedded Defects In Carbon Nanofiber Via Interconnects, Makoto Suzuki, Yusuke Ominami, Takashi Sekiguchi, Cary Y. Yang

Electrical and Computer Engineering

Carbon nanofiber (CNF) via interconnect test structures are fabricated with the bottom-up process proposed by Li et al. [Appl. Phys. Lett. 82, 2491 (2003)] for next-generation integrated circuit technology. Critical defects in the interconnect structure are examined using scanning electron microscopy. It is shown that secondary electron signal with optimized incident beam energy is useful for detecting embedded defects, including unexposed CNF plugs and voids in the dielectric layer. The defect imaging mechanisms are elucidated based on beam-induced charging of the specimen surface.


A Front End Switched Rectifier Dc Source For Neutral Point Balancing Of A Npc Three-Level Inverter For The Full Modulation Range, K. Siva Kumar, Sukumar De, K. Gopakumar, Gopal Mondal, Keith Corzine Dec 2008

A Front End Switched Rectifier Dc Source For Neutral Point Balancing Of A Npc Three-Level Inverter For The Full Modulation Range, K. Siva Kumar, Sukumar De, K. Gopakumar, Gopal Mondal, Keith Corzine

Electrical and Computer Engineering Faculty Research & Creative Works

A switched DC voltage three level NPC is proposed in this paper to eliminate capacitor balancing problems in conventional three-level Neutral Point Clamped (NPC) inverter. the proposed configuration requires only one DC link with a voltage Vdc/2, where Vdc is the DC link voltage in a conventional NPC inverter. to get rated DC link voltage (Vdc), the voltage source is alternately connected in parallel to one of the two series capacitors using two switches and two diodes with device voltage rating of Vdc/2. the frequency at which the voltage source is switched is independent and will not affect the operation …


Integrated Approach To Airborne Laser Communication, James A. Louthain Dec 2008

Integrated Approach To Airborne Laser Communication, James A. Louthain

Theses and Dissertations

Lasers offer tremendous advantages over RF communication systems in bandwidth and security, due to their ultra-high frequency and narrow spatial beamwidth. Atmospheric turbulence causes severe received power variations and high bit error rates (BERs) in airborne laser communication. Airborne optical communication systems require special considerations in size, complexity, power, and weight. Conventional adaptive optics systems correct for the phase only and cannot correct for strong scintillation, but here the two transmission paths are separated sufficiently so that the strong scintillation is \averaged out" by incoherently summing up the two beams in the receiver. This requisite separation distance is derived for …


Sub-Circuit Selection And Replacement Algorithms Modeled As Term Rewriting Systems, Eric D. Simonaire Dec 2008

Sub-Circuit Selection And Replacement Algorithms Modeled As Term Rewriting Systems, Eric D. Simonaire

Theses and Dissertations

Intent protection is a model of software obfuscation which, among other criteria, prevents an adversary from understanding the program’s function for use with contextual information. Relating this framework for obfuscation to malware detection, if a malware detector can perfectly normalize a program P and any obfuscation (variant) of the program O(P), the program is not intent protected. The problem of intent protection on programs can also be modeled as intent protection on combinational logic circuits. If a malware detector can perfectly normalize a circuit C and any obfuscation (variant) O(C) of the circuit, the circuit is not intent protected. In …


Discrete-Time Output Feedback Sliding Mode Control For Uncertain Systems, Ming-Chang Pai Dec 2008

Discrete-Time Output Feedback Sliding Mode Control For Uncertain Systems, Ming-Chang Pai

Journal of Marine Science and Technology–Taiwan

This paper presents a discrete-time output feedback sliding mode control to stabilize a class of linear uncertain systems in which the state is unavailable and no estimated state is required. The proposed sliding mode controller is derived to guarantee the existence of quasi-sliding mode by using output feedback only and the stability of overall closed-loop system is assured. This scheme ensures the robustness against parametric uncertainties and disturbances. Neither chattering phenomenon will occur nor the knowledge of upper bound of uncertainties is required. Simulation results demonstrate the efficacy of the proposed control methodology.


Estimating Tmr Reliability On Fpgas Using Markov Models, Daniel Mcmurtrey, Keith S. Morgan, Brian Pratt, Michael J. Wirthlin Dec 2008

Estimating Tmr Reliability On Fpgas Using Markov Models, Daniel Mcmurtrey, Keith S. Morgan, Brian Pratt, Michael J. Wirthlin

Faculty Publications

This paper summarizes several reliability models for modeling FPGA reliability using Markov models.


Electromagnetic Emissions Stimulation And Detection System, Daryl G. Beetner, Sarah A. Seguin, Todd H. Hubing Dec 2008

Electromagnetic Emissions Stimulation And Detection System, Daryl G. Beetner, Sarah A. Seguin, Todd H. Hubing

Electrical and Computer Engineering Faculty Research & Creative Works

A system and method for detecting and identifying electronic devices based on their unintended electromagnetic emissions (“UEE”) signals is presented. During device classification, UEE signals are measured from a plurality of test devices and characteristic data is obtained from the UEE signal emitted from each test device. Using the characteristic data, a threshold value and ideal pulse template can be determined for each test device and stored in a memory. An ideal stimulation signal is also determined for each test device and stored in the memory. During device detection, the ideal stimulation signal is applied to the environment in which …


Automatic Generation Of Decomposition Based Matrix Inversion Architectures, Ali Irturk, Bridget Benson, Arash Arfaee, Ryan Kastner Dec 2008

Automatic Generation Of Decomposition Based Matrix Inversion Architectures, Ali Irturk, Bridget Benson, Arash Arfaee, Ryan Kastner

Electrical Engineering

Matrix inversion is an essential computation for various algorithms which are employed in multi-antenna wireless communication systems. FPGAs are ideal platforms for wireless communication; however, the need for vast amounts of customization throughout the design process of a matrix inversion core can overwhelm the designer. Decomposition methods provide the analytic simplicity and computational convenience necessary for computationally intensive matrix inversion. This paper presents automatic generation of different decomposition based matrix inversion architectures using a matrix inversion core generator tool, GUSTO with different parameterization options. We present automatic generation of a variety of general purpose matrix inversion architectures which have comparable …


Secondary Electron Emission From Freely Supported Nanowires, Makoto Suzuki, Kazuhiro Kumagai, Takashi Sekiguchi, Alan M. Cassell, Tsutomu Saito, Cary Y. Yang Dec 2008

Secondary Electron Emission From Freely Supported Nanowires, Makoto Suzuki, Kazuhiro Kumagai, Takashi Sekiguchi, Alan M. Cassell, Tsutomu Saito, Cary Y. Yang

Electrical and Computer Engineering

We present secondary electron (SE) emission results from freely supported carbon/silicon nitride (Si3N4) hybrid nanowires using scanning electron microscopy. We found that, contrary to bulk materials, the SE emission from insulating or electrically isolated metallic nanowires is strongly suppressed by the penetrating beam. A mechanism of the SE suppression by the positive specimen charging is proposed, which is based on a total emission yield calculation using the Monte Carlo technique. This finding provides an important basis for studying low-energy electron emission from nanostructures under a penetrating electron beam.


Load Sharing Characteristic Of Single Phase Pv Inverter Connected To Grid, M. Imram Hamid, Makbul Anwari, Z. Salam, Taufik Dec 2008

Load Sharing Characteristic Of Single Phase Pv Inverter Connected To Grid, M. Imram Hamid, Makbul Anwari, Z. Salam, Taufik

Electrical Engineering

This paper describes model and simulation of single phase PV inverters that work independently to supply three phase system as a part of renewable distributed generation. Load sharing characteristic of PV inverter and grid during supplying local load with current control method and relation of PV power level and current control performance to load sharing are simulated and analyzed. Furthermore, power quality behavior during connection/disconnection of PV plant, grid harmonics, voltage and current unbalance are simulated and analyzed. Model and simulation are implemented using MATLAB/Simulink.


A Small Scale Static Var Compensator For Laboratory Experiment, Taufik, Bryan Paet Dec 2008

A Small Scale Static Var Compensator For Laboratory Experiment, Taufik, Bryan Paet

Electrical Engineering

This paper presents a small scale static VAR compensator (SVC) circuit that could be used as either a laboratory demonstration or a laboratory experiment. The small scale SVC lab experiment effectively demonstrates SVCpsilas function in correcting power factor through the use of power thyristors in a phase-controlled circuit. The laboratory setup of the SVC circuit using a thyristor controlled reactor in parallel with a capacitor will discussed in this paper. Results from the lab setup to exhibit firing angle adjustment to inject or absorb VARs into the system will also be described.


Impact Of Multiple Adjustable Speed Drive System To Power System Harmonics, Taufik, Erin Matsumoto, Makbul Anwari Dec 2008

Impact Of Multiple Adjustable Speed Drive System To Power System Harmonics, Taufik, Erin Matsumoto, Makbul Anwari

Electrical Engineering

This paper presents harmonic analysis in a multiple adjustable speed drive system. In a system where multiple drives are fed from the same bus, harmonic currents produced by the various drives can reflect back to the power source and to the other drives causing distortion of the voltage waveform. If these harmonic currents are significant, they can potentially cause problems for the given system. Therefore studying the harmonics at various points in the system and comparing the values of total harmonic distortion can provide guidance in choosing appropriate filtering solutions. A two AC drive system was setup in a laboratory …


Power Quality Behavior Of Single Phase Fed Adjustable Speed Drive Supplied From Grid Of Pv Generation, Makbul Anwari, M. Imran Hamid, Taufik Dec 2008

Power Quality Behavior Of Single Phase Fed Adjustable Speed Drive Supplied From Grid Of Pv Generation, Makbul Anwari, M. Imran Hamid, Taufik

Electrical Engineering

Power quality behavior on connecting single phase fed adjustable speed drives to a grid which photovoltaic as the power generation is studied in this paper. A MATLAB/Simulink simulations are performed to investigate the existence of power quality parameter and the system problems that may be resulted from operation of this type of load. The results indicate a potential serious power quality problem with the connected adjustable speed drives, which requires consideration during operation of PV generation which a number of this dynamic load.


A Study Of Switched-Capacitor Filters, Kacie Thomas Dec 2008

A Study Of Switched-Capacitor Filters, Kacie Thomas

Electrical Engineering Undergraduate Honors Theses

This paper presents the basic principles of the switched-capacitor circuit. In order to become more acquainted with the workings and design of filters and switched-capacitor filters specifically, an example filter was designed based on a set of parameters. It was constructed starting in the passive stage, then the active stage and finally the switched-capacitor filter was generated. All of these circuits were also simulated using SwitcherCAD and Saber. Then, a switched-capacitor filter designed by Auburn University was redesigned using the same process as the example circuit. It was also simulated in all three stages. The results from this design are …


Analysis And Design Of Interleaving Multiphase Dc-To-Dc Converter With Input Lc Filter, Kevin Thomas Delrosso Dec 2008

Analysis And Design Of Interleaving Multiphase Dc-To-Dc Converter With Input Lc Filter, Kevin Thomas Delrosso

Master's Theses

The future of microprocessors is unknown. Over the past 40 years, their historical trend has been for adopting smaller and more powerful designs that drive the world that we live in today. The state of the microprocessor business today faces a crossroad, wishing to continue on the historical trend of doubling the number of transistors on a chip every 18 months (Moore’s Law) but also facing the realistic task of needing to power these sophisticated devices. With the low voltages and high currents that are required for these microprocessors to operate, it poses a difficult task for the future designers …


High Speed Wavelength Tuning Of Sgdbr Lasers For Optical Coherence Tomography Applications, Benjamin Maher Dec 2008

High Speed Wavelength Tuning Of Sgdbr Lasers For Optical Coherence Tomography Applications, Benjamin Maher

Master's Theses

The application of Sample Grated Distributed Bragg Reflector (SGDBR) wavelength tunable lasers for swept-wavelength Optical Coherence Tomography (OCT) is explored. OCT is a method of measuring reflectivity versus distance into samples under test with a focused infrared light source. Swept wavelength OCT requires a laser light source that is capable of sweeping its wavelength quickly over the entire wavelength range of the tunable laser. Fast sweeping of the laser's wavelength enables real-time imaging of a wide surface area of the surface under test. This thesis will show that SGDBR lasers can be designed to meet the fast wavelength ramp speeds …


A Comparison Of Three Phase Induction Motor Performance Subjected To Frequency, Voltage, And Load Changes By Pwm And Square Wave Inverters, Aliosman Demirbas Dec 2008

A Comparison Of Three Phase Induction Motor Performance Subjected To Frequency, Voltage, And Load Changes By Pwm And Square Wave Inverters, Aliosman Demirbas

Masters Theses and Doctoral Dissertations

This paper presents a comparison of three-phase induction motor performance subjected to frequency, voltage and load changes by Square wave inverter and Pulse Width Modulated (PWM) inverter. A computer program which is backed by a laboratory study is used to characterize the motor performance during the comparison. A 1 hp induction motor is tested by a Square wave and a PWM inverter and the motor performance data including various harmonic losses at 30 Hz, 40 Hz and at 60 Hz are measured. An advanced electrical model that accounts for the skin effect in the rotor bar to predict motor impedance …


A Circuit Model For Esd Performance Analysis Of Printed Circuit Boards, Byong-Su Seol, Jong-Sung Lee, Jae-Deok Lim, Hyungseok Lee, Harkbyeong Park, Argha Nandy, David Pommerenke Dec 2008

A Circuit Model For Esd Performance Analysis Of Printed Circuit Boards, Byong-Su Seol, Jong-Sung Lee, Jae-Deok Lim, Hyungseok Lee, Harkbyeong Park, Argha Nandy, David Pommerenke

Electrical and Computer Engineering Faculty Research & Creative Works

This paper provides a SPICE-compatible circuit model for characterizing electrostatic discharge (ESD) clamping performance of protection devices mounted on printed circuit boards (PCBs). An equivalent circuit model for a commercial ESD generator is introduced and a simulation methodology of an ESD protection device with non-linear resistance characteristic using voltage controlled current source is described. These models combined to create a full circuit model with a PCB model in a SPICE-like circuit simulator. Comparison results between the simulated and measured are presented to verify the accuracy of the proposed circuit model. A trade-off analysis between the ESD clamping performance and signal …


Development Of A New System Vulnerability Index - The Overload Risk Index, John Rossmaier, Badrul Chowdhury Dec 2008

Development Of A New System Vulnerability Index - The Overload Risk Index, John Rossmaier, Badrul Chowdhury

Electrical and Computer Engineering Faculty Research & Creative Works

This paper proposes a new index to better determine the vulnerability of a power system. the procedure for calculating this index combines stochastic and probabilistic methods to determine the likelihood of a line overloading in a power system. the methods used include a basic load flow analysis using network security factors and Monte Carlo simulation that incorporates the likelihood of component failure within the system. a case study has been performed to analyze the ability of such an index in accurately measuring one aspect of power system vulnerability. Three different variations of this indexing method are explored in an attempt …