Digital Commons Network^™

System Design Analysis Of A Lightweight Laser Satellite Terminal, Brian C. Page

Theses and Dissertations

This study investigated the technological feasibility of a man- portable satellite laser communications system. Areas of interest were an end- to-end system analysis on the communications link evaluation of atmospheric effects and evaluation of semi-conductor lasers as the laser source. A literature search revealed that satellite laser communication research is primarily directed at inter-satellite links. There have been some proposed systems for space-to-ground laser communications systems, but they all utilize large fixed ground stations. The focus of this research effort is directed at a small man-portable ground station capitalizing on recent advances in semiconductor laser devices. Baseline satellite communication systems …

Simple High-Quality Lossy Image Coding Scheme, Shaolin Bi, Khalid Sayood

Department of Electrical and Computer Engineering: Faculty Publications

A simple yet efficient image data compression method is presented. This method is based on coding only those segments of the image that are perceptually significant to the reconstruction of the image. Sequences of image pixels whose gray-level differences from the pixels of the previous row exceed two prespecified thresholds are considered significant. These pixels are coded using a differential pulse code modulation scheme that uses a 15-level recursively indexed nonuniform quantizer for the first pixel in a segment and a 7-level recursively indexed nonuniform quantizer for all other pixels in the segment. The quantizer outputs are Huffman coded. Simulation …

Pattern Recognition And Erp Waveform Analysis Using Wavelet Transform, Hong Qi

Dissertations and Theses

Wavelet transform provides an alternative to the classical Short-Time Fourier Transform (STFT). In contrast to the STFT, which uses a single analysis window, the Wavelet Transform uses shorter windows at higher frequencies and longer windows at lower frequencies. For some particular wavelet functions, the local maxima of the wavelet transform correspond to the sharp variation points of the signal. As an application, wavelet transform is introduced to the character recognition. Local maximum of wavelet transform is used as a local feature to describe character boundary. The wavelet method performs well in the presence of noise. The maximum of wavelet transform …

Obscured Object Detection Via Bayesian Target Modeling Techniques, Rufus H. Cofer

Electrical Engineering and Computer Science Faculty Publications

Underground objects are by nature often severely obscured although the general character of the intervening random media may be reasonably understood. The task of detecting these underground objects also implies that their exact location and or orientation is not known. To partially counter these difficulties, one may; however, be given a model of the target of interest, e.g. a particular tank type, a water pipe, etc. To set up a quality framework for solution of the above problem, this paper utilizes the paradigm of Bayesian decision theory that promises minimum error detection given that certain probability density functions can be …

Sensitivity Improvement Of A 1-Μm Ladar System Incorporating An Active Optical Fiber Preamplifier, Michael S. Salisbury, Paul F. Mcmanamon, Bradley D. Duncan

Electro-Optics and Photonics Faculty Publications

In an effort to increase the SNR of a continuous wave, 1-μm all solid state ladar system, a rare-earth-doped optical fiber amplifier is investigated as a preamplifier for ladar return signals. The experimental system is detailed and a theoretical analysis of the fiber amplifier's effect on both heterodyne and direct detection schemes is provided. Beginning with the optical powers incident on the detector, the signal and noises are analyzed, through the detector electronics, to predict the SNR. The SNR is then plotted as a function of the return signal power, and a SNR threshold is defined to determine a minimum …

Periodic Pn Sequence Delay Estimation Using Phase Spectrum Data, Kurt Louis Kosbar, Jorge J. Zaninovich

Electrical and Computer Engineering Faculty Research & Creative Works

An algorithm for estimating the delay of a periodic pseudonoise (PN) sequence is presented. It is a rapid, block-based estimator that can be used for both linear and nonlinear codes. The algorithm exploits the periodicity of the difference between the phase spectra of the received sequence and a local reference. The estimator takes the Fourier transform of the phase spectrum difference data, and searches for the fundamental frequency. Unlike previously described methods, phase unwrapping is not required. The performance in the presence of additive white Gaussian noise (AWGN) and a continuous wave (CW) jammer is investigated using computer simulation. Comparisons …

On Generalized Adaptive Neural Filter, Zhiqiang Zhang

Dissertations

Linear filters have historically been used in the past as the most useful tools for suppressing noise in signal processing. It has been shown that the optimal filter which minimizes the mean square error (MSE) between the filter output and the desired output is a linear filter provided that the noise is additive white Gaussian noise (AWGN). However, in most signal processing applications, the noise in the channel through which a signal is transmitted is not AWGN; it is not stationary, and it may have unknown characteristics.

To overcome the shortcomings of linear filters, nonlinear filters ranging from the median …

A High-Temperature Pressure Sensor Utilizing Linear Voltage Differential Transformer (Lvdt) And Silicon Wafer-To-Wafer Fusion Bonding Technologies, Robert Sylvester Okojie

Theses

A novel high-temperature pressure sensor was designed based on the principle of magnetic induction. The device is meant to correct the problems inherent in conventional Solid-State pressure transducers such as piezoresistive and capacitive at temperatures above 300°C. Prominent among these problems are increased leakage current, reduced absolute sensitivity, redistributed impurity concentration profile, and thermal mismatch.

This thesis combined the Biot Savart magnetostatic principle and the theory of deflecting clamped circular plates to obtain the microelectromechanical relationship. The problem of thermal mismatch was resolved by the symmetrical layering of a Si₃N₄/TaSi₂/Si₃N₄ sandwich, …

Magnetohydrodynamic Behavior Under Current Impulse Excitation, Shi Wu

Theses

The effects of magnetic field on magnetohydrodynamic (MHD) channel flow between two parallel plates of infinite extent are investigated. The applied magnetic field is due to an infinite impulse current-carrying conductor located a small distance below the lower channel wall. Influence of the induced magnetic field, such that the magnetic Reynolds number (R_m) is less than unity but greater than zero, is included. The solution is obtained using the perturbation theory in the expansion of the field components in a double-power series in R_m and I. Calculations for the magneto-fluid components were carried out using personal computer. …

Design, Fabrication And Characterization Of Infrared Filters, Samiul Amin

Theses

In-situ temperature monitoring, mapping, and control have become significant in semiconductor processes. Temperature of these processes can be measured by making use of the thermal emission from substrates in the infrared region. Various methods have been proposed to provide multicolor infrared detection. One such method involves placing segmented infrared filters close to the focal plane. The present study aims at gaining an insight into the design, fabrication and characterization of infrared filters. Filters were designed and fabricated with peak transmission at 1.5, 3.0, and 4.5 m. Extensive spectroscopic studies, using FTIR spectroscopy, have been performed in the infrared region, on …

Traffic Management Of A Satellite Communication Network Using Stochastic Optimization, Ambalavanar Arulambalam

Theses

The performance of nonhierachial circuit switched networks at moderate load conditions is improved when alternate routes are made available. However, alternate routes introduce instability under heavy and overloaded conditions, and under these load conditions network performance is found to deteriorate. To alleviate this problem, a control mechanism is used where, a fraction of the capacity of each link is reserved for direct routed calls.

In this work, a traffic management scheme is developed to enhance the performance of a mesh-connected, circuit-switched satellite communication network. The network load is measured and the network is continually adapted by reconfiguring the map to …

Model Parameter Identification Of The Oscillatory Potential In The Electroretinogram, Sung Hoon Jang

Theses

A mathematical model of the oscillatory potential which may be a useful clinical tool to diagnose the progression of diabetic retinopathy. The model has been investigated by compressing from oscillatory potential into three parameters which contain most of the information for the oscillatory potential data.

About thirty subjects including both normal and diabetic subjects were investigated in this study. Comparing normal and diabetic subjects, we found amplitude parameter was most important factor to classify subjects by normal and diabetic.

Since modeling of the oscillatory potential and the estimation of the model parameters were our final goal, we haven't proposed to …

Object Oriented Design Of Petri Net Simulator, Himanshu Juneja

Theses

Petri nets are highly useful for modeling discrete event dynamic systems. The objective of this effort is to develop a tool for drawing, editing and simulating Petri nets using object oriented programming on a standard platform. The object oriented approach was chosen because of its code reuse and extendability features which simplify the task of adding features to the tool as the model evolves. The design stresses on modeling of the problem by objects which closely relate the system design with the implementation.

C++ is used for implementing the object oriented design, and the XView toolkit is used for building …

Simplification Of The Generalized Adaptive Neural Filter And Comparative Studies With Other Nonlinear Filters, Henry Steven Hanek

Theses

Recently, a new class of adaptive filters called Generalized Adaptive Neural Filters (GANFs) has emerged. They share many characteristics in common with stack filters, include all stack filters as a subset. The GANFs allow a very efficient hardware implementation once they are trained. However, there are some problems associated with GANFs. Three of these arc slow training speeds and the difficulty in choosing a filter structure and neural operator.

This thesis begins with a tutorial on filtering and traces the GANF development up through its origin -- the stack filter. After the GANF is covered in reasonable depth, its use …

Modeling Of Rapid Thermal Processing System By Finite Element Method, Helen Martynov

Theses

A finite element model for the Rapid Thermal Processing (RTP) system at NJIT was developed based on the software package MSC/NASTRAN. Based on this model, a thermal analysis of the 9" chamber, 3 zones (37 lamps) RTP system was conducted for various modes of system operation with the 6" silicon wafer temperature varying from 300°K to 1100°K. An open-loop control algorithm was developed in order to study the dependence of wafer temperature on time, position, and applied radiant heat distribution. It was shown that the non-uniformity in the radial temperature profile can be less than 3°C during wafer heating at …

Real Time Control Of A Dual Resonator System, Penghuai Shen

Theses

An experimental multi-resonator system has been developed to study modelling and robust control of such systems in a real-time environment. The plant to be controlled consists of a pair of interconnected resonators whose resonant frequency and plant structure are known. The control objectives are to provide closed loop stability and asymptotic regulation of the frequency, gain and phase of each of the resonators. Furthermore, it is desired to use a minimal controller configuration so as to reduce implementational complexity.

The theoretical results follow directly the paper " Decentralized Robust Control of Interconnected Resonators" written by my advisor Dr. Timothy N. …

Design Of Mask For Striped Filters And Thin-Film Multi-Layer Emissivity Modeling For Multi-Wavelength Imaging Pyrometer, Jitesh Navinchandra Shah

Theses

Multi-Wavelength Imaging Pyrometry (M-WIP) measures thermal radiation of any target (color or gray) in multiple narrow-spectral-regions and can simultaneously determine target temperature and emissivity. One approach for measuring radiation at multiple wavelengths using a 320X244 element Pt-Si SBD infrared camera is to use narrow-band striped filters deposited on a transparent substrate with proper alignment. The major focus of this thesis was the design of a four layer mask for investigating the feasibility of defining three-wavelength striped filters compatible with focal plane array. This mask design allows twelve distinct narrow band striped filter geometries and four test-patterns on a 4-inch silicon …

Rigorous Te Solution To The Staircase Model Of The Dielectric Wedge Antenna, Wan-Yu Chen

Theses

The rigorous TE solution to the staircase model of the dielectric wedge antenna is presented. The fundamental, even TE surface wave mode of the dielectric slab waveguide is taken to excite a dielectric wedge which is formed by symmetrically tapering the slab. The method of solution is based on Marcuse's step-transition method. Radiation patterns of power gain are presented which show increased maximum power gains and narrower main lobe beamwidths for longer wedges. For higher dielectric constant material, the main lobe beamwidth is increased. In all cases examined, negligible sidelobes were obtained.

Proposal For A Dod Combined Battlefield Electromagnetic Environmental Effects (E3) Initiative, George H. Baker Iii

School of Integrated Sciences - Faculty Scholarship

The presentation emphasizes the growing importance of electromagnetic survivability and compatibility. Operation Desert Storm demonstrated the clear military advantage provided by sophisticated electronic weapon and communication systems. In addition, the offensive tactic of taking out the enemy's eyes and ears during the air war paid off, giving our military decisive air superiority. The lessons for the future are clear. High-tech electronics now so dominates the battlefield that the outcome of future conflicts could well be decided by electronics attrition rather than human casualties. Our Desert Storm experience thus accentuates the importance of guaranteeing that our electronic systems will not be …

Acoustic Correlates Of Vowel Perception As Determined From Synthesis Experiments With Multi-Tone Stimuli, Zhongjiang Zhang

Electrical & Computer Engineering Theses & Dissertations

An essential requirement of speech signal processing is to extract information (features or parameters) from the speech signal which encode the information carried by the signal. The objective of this thesis work was to examine and evaluate two feature sets as acoustic correlates for vowel perception. They are formants and DCTCs. Formants are the frequencies of spectral peaks of the speech signal. DCTCs are the Discrete Cosine Transform Coefficients of the magnitude spectrum and are thus features which encode the global spectral shape of speech signal.

There are different opinions regarding which feature set is a more accurate representation for …

Fluttering Fountains: Simplified Models, Lee W. Casperson

Electrical and Computer Engineering Faculty Publications and Presentations

Fluttering oscillations are sometimes observed in the falling sheets of water associated with dams and waterfall fountains, and a theoretical simulation of this phenomenon was recently reported. In this study approximate analytical solutions of the previous model are described and compared with the experimental and theoretical observations.

Identification Of Variegated Coloring In Skin Tumors: Neural Network Vs. Rule-Based Induction Methods, Ajaya Durg, William V. Stoecker, J. P. Cookson, Scott E. Umbaugh, Randy Hays Moss

Chemistry Faculty Research & Creative Works

The use of neural networks for automatic identification of variegated coloring, which is believed to be one of the most predictive features for malignant melanoma, is described. The Nestor development system (NDS) was chosen for neural network implementation. At the heart of NDS is a three-layer neural network called a restricted Coulomb energy (RCE) network. The learning scheme and the database for detection of variegated coloring are discussed. Results are reported

Investigation Of The Sensitivity, Selectivity, And Reversibility Of The Chemically-Sensitive Field-Effect Transistor (Chemfet) To Detect Nitrogen Dioxide, Dimethyl Methylphosphonate, And Boron Trifluoride, Neal T. Hauschild

Theses and Dissertations

This study investigated the sensitivity, selectivity, and reversibility of a chemically-sensitive field-effect transistor (CHEMFET) gas microsensor. Various physical operating parameters were tested to determine which produced the most significant sensitivity, selectivity, and reversibility which were computed from response changes generated from electrical conductivity modulations when exposed to challenge gases. The variable operating parameters included: thinfilm material, film thickness, challenge gas specie, challenge gas concentration, and operating temperature. Copper phthalocyanine and lead phthalocyanine were used as thin films to detect the following challenge gases: nitrogen dioxide, dimethyl methylphosphonate, boron trifluoride, methanol, carbon monoxide, vinyl chloride, and trichloroethylene. Tests revealed that copper …

Characterization Of A Resistive Half Plane Over A Resistive Sheet, John R. Natzke, John L. Volakis

Faculty Publications - Department of Electrical Engineering and Computer Science

The diffraction of a resistive half plane over a planar resistive sheet under plane wave illum1ination is determined via the dual integral equation method (a variation of the Wiener-Hopf method). The solution is obtained upon splitting the associated Wiener-Hopf functions via a numerically efficient routine. Based on the derived exact half plane dliffraction coefficient, a simplified equivalent model of the structure is developed when the separation of the half plane and resistive plane is on the order of a tenth of a wavelength or less. The model preserves the geometrical optics field of the original structure for all angles and …

Electronic Simulation Of The Temporal Characteristics Of Photon Memory Echoes And Some Related Applications, Yuwen Kuo, Monish Ranjan Chatterjee

Electrical and Computer Engineering Faculty Publications

The characteristics of nonlinear photon memory echoes are investigated by means of SPICE simulations using equivalent resonator ensembles. By developing implicit nonlinear circuit models in the memory echo domain, the triple product formalism of electronic holography, involving correlation and convolution, is tested for the storage and recall of arbitrary signals and/or data bit streams in both time-inverted and nontime-inverted modes. Furthermore, a few specific optical data processing applications are also simulated in which the mixed binary multiplication of two or more binary bit streams is achieved.

Higher order products, optical pattern recognition, and other possible applications are also discussed. It …

A Study Of Numerically Efficient Algorithms For Power System Dynamic Analysis, J. G. Chen, Mariesa Crow

Electrical and Computer Engineering Faculty Research & Creative Works

In this paper, the multirate method is introduced to analyze power system behavior including linear and nonlinear systems with widely varying time constants. The development and study of time domain simulation techniques and error detection are discussed. The results, both in terms of accuracy and computation time, are compared to traditional simulation methods in a small nonlinear power system example

An Algorithm For Automated Printed Circuit Board Layout And Routing Evaluation, Todd H. Hubing, Thomas Van Doren, James L. Drewniak, Puneet Grover, R. Lee Hill

Electrical and Computer Engineering Faculty Research & Creative Works

An algorithm has been developed to evaluate printed circuit boards that are designed using automated board layout and routing software. The algorithm analyzes aspects of component placement and trace routing while searching for violations of basic EMC design principles. The algorithm is implemented in code designed to work with a widely used board layout and routing program. This code can help novice and experienced circuit board designers to avoid mistakes that may result in serious electromagnetic compatibility problems.

Robust Linear Quadratic Regulation Using Neural Network, Kisuck Yoo, Michael Thursby

Electrical Engineering and Computer Science Faculty Publications

Using an Artificial Neural Network (ANN) trained with the Least Mean Square (LMS) algorithm we have designed a robust linear quadratic regulator for a range of plant uncertainty. Since there is a trade-off between performance and robustness in the conventional design techniques, we propose a design technique to provide the best mix of robustness and performance. Our approach is to provide different control strategies for different levels of uncertainty. We describe how to measure these uncertainties. We will compare our multiple strategies results with those of conventional techniques e.g. H∞ control theory. A Lyapunov equation is used to define stability …

Low‐Cost Technique For Preparing N‐Sb2S3/P‐Si Heterojunction Solar Cells, O. Savadogo, K. C. Mandal

Faculty Publications

No abstract provided.

Detecting Chaotic Signals With Nonlinear Models, Qin Cai

Dissertations and Theses

In this thesis we apply chaotic dynamic data analysis to the area of discrete time signal processing. A newly developed Hidden Filter Hidden Markov Model is introduced in detection of chaotic signals. Numerical experiments have verified that this novel nonlinear model outperforms linear AR model in detecting chaotic signals buried by noise having similar power spectra. A simple Histogram Model is proposed which can also be used to do detection on the data sets with chaotic behavior. Receiver Operating Characteristics for a variety of noise levels and model classes are reported.