Electrical and Computer Engineering Commons^™

Hardware Design For Jpeg And A Comparative Study Of Jpeg And Mpeg Image Compression Algorithms, Aravind Soundararajan

Theses

The complete PC-based hardware design along with the initialization and control software of the JPEG algorithm is presented in this thesis. The hardware could run in real-time to compress, decompress and display still frame images. LSI Logic JPEG chipset was used in the design. This is a dedicated chipset for the JPEG compression algorithm.

A simulation software was used for studying the performance of MPEG video compression algorithm. Various video test sequences were compressed through the codec simulation software and the resulting rate-distortion performance was calculated. These are compared with the performance of JPEG based image sequence compressor.

It is …

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. …

Comparison Between Stimulated Emg And Natural Emg, Zak Belfki

Theses

The electromyograph (EMG) signal generated from a cat's jaw muscle in movement, is analyzed. After a series of experiments at UMDNJ, three major categories of EMG were recorded: rest EMG, biting EMG and hissing EMG.

The biting files contained a series of EMG collected in successive episodes. Power spectrum and statistical analysis were applied to the episodes. Each episode had approximately 43,000 samples. Results showed that these episodes had a similar spectrum with statistically the same mean and variance.

The hissing files were produced by electrical stimulation of the hypothalamus and contained EMG embedded in a stimulus artifact. The problem …

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, …

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 …

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.

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 …

The Spirit Iii Radiometer Data Compression System, Scott E. Budge

Electrical and Computer Engineering Faculty Publications

In this paper, we describe the image data compressor designed and built for the SPIRIT III radiometer which will be used to provide a real-time "quick-look" capability for the instrument. A a brief description of elements of the radiometer design which determine the data compression requirements is given, followed by a description of the VQ-based hybrid data compression algorithm. Highlights of the hardware design are also discussed.

The performance of the compressor is presented. Tests made using data obtained during cold tests of the instrument indicate an RMS error of 6.26 counts for the 10:1 compression mode and 5.83 counts …

Simulation Of Switched Linear Networks, Dietmar Reinhard Skowronn

Dissertations and Theses

This thesis deals with the time-domain analysis of switched linear networks and investigates inherent problems which have to be considered when analyzing this class of networks. Computer simulation requires the use of numerical methods and we focus on the transmission -line modelling technique (TLM) and the numerical inverse Laplace transform. A general approach based on the one-graph modified nodal description is given which allows the formulation of circuit equations of a TLM-modelled circuit by inspection. The numerical equivalence of TLM and trapezoidal rule has been found and a proof is given. A variable step size simulator has been developed based …

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 …

Coordinated Intelligent Control Via Epistemic Utility Theory, Wynn C. Stirling

Faculty Publications

An approach to local reactive coordinated intelligent control based on the concept of an epistemic system, together with a principle of action that may be exercised locally, is presented. An epistemic system provides a mechanism for agents to characterize their knowledge corpora, options, goals, and beliefs. Levi's rule of epistemic utility provides a principle of action for decision making by comparing the informational value of rejection with the belief of correctness. Decisions are made locally and reactively, rather than globally. Coordination is implemented between agents by sharing and learning the epistemic systems of other agents. The resulting coordination model is …

Two-Dimensional Simulation Of Switch-On Speeds In Hydrogenated Amorphous Silicon Thin-Film Transistors, J. S. Huang, Cheng-Hsiao Wu

Electrical and Computer Engineering Faculty Research & Creative Works

We report accurate two-dimensional simulations of switch-on speeds in hydrogenated amorphous silicon thin-film transistors. The trap charge density along, or transverse to, the direction of semiconductor channel is highly nonuniform and the trap filling time dominates the switching time as compared to the transit time, which is about four orders of magnitude smaller. Near both contacts, direction of the transverse current is always upwards toward the insulator-semiconductor interface due to the strong electric fields. However, at the central region of the channel, the transient current is quite complex and is discussed here. When the channel length varies from 2 to …

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.

Gyroless Line-Of-Sight Stabilization For Pointing And Tracking Systems, Marcelo C. Aigrain

Department of Electrical and Computer Engineering: Faculty Publications

A new platform stabilization approach is described where miature, low-cost, linear accelerometers are used (instead of gyroscopes) for line-of-sight (LOS) stabilization. This is accomplished by placing the accelerometers at strategic locations and combining their outputs so that angular motion is determined from linear acceleration measurements. The control system uses the sensed angular accelerations to generate movement commands for the gimbal servomotors in the stabilization platform. This counterrotates the imaging device to stabilize its LOS. The use of accelerometers allows the servo system to operate in an acceleration control mode, which is more desirable than position or velocity control modes, typical …

A Study Of Spiking And Relaxation Oscillations In Nd:Yag Laser Using Measured Laser Parameters, Ramesh K. Shori

Dissertations and Theses

It was shown analytically and experimentally that when the cavity losses are perturbed, the output intensity experiences an amplitude modulation or becomes a regular train of spikes, with the frequency depending on both the frequency of perturbation as well as pump power. Coupled nonlinear rate equations including the cavity perturbation term, are solved numerically by a Runga-Kutta method using experimentally-measured parameter values for Nd: Y AG laser. A continuously pumped Nd: Y AG laser was used to verify this theory.

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

Transition Mechanisms Of Two Interacting Dx Centers In N-Type Algaas Using Reverse-Bias Deep Level Transient Spectroscopy And Temperature-Dependent Pulse-Width Reverse-Bias Deep Level Transient Spectroscopy Methods, C. W. Wang, Cheng-Hsiao Wu

Electrical and Computer Engineering Faculty Research & Creative Works

The reverse-bias pulsed deep level transient spectroscopy (RDLTS) and a new temperature-dependent pulse-width RDLTS (TDP RDLTS) technique are reported to study the electric-field effect on carrier emission rates and the direct interaction between double DX centers recently detected in the Se:Al_0.6Ga_0.4As N confinement layer of the AlGaAs/GaAs single-quantum-well laser diodes. Traditional RDLTS measurements, with constant pulse width t_p, prove that the two DX centers, Et₁ and Et₂, have strong direct emission interaction. Furthermore, the new TDP-RDLTS technique enables one to evaluate this direct transition time constant. Possible mechanisms for this interstate …

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 …

Electric Fields Of An H-Plane Tapered Iris, John R. Natzke, T. Koryu Ishii

Faculty Publications - Department of Electrical Engineering and Computer Science

Microwave electric fields of an X -band H -plane tapered iris are calculated and plotted using the moment method for the first time. The moment method results are compared with previously obtained experimental measurements and numerical results based on an equivalent circuit approach, giving confirmation that the tapered iris is both a reciprocal and asymmetrical network. The moment method results now reveal that the asymmetry stems from the asymmetry in the phase of the input and output voltage reflection coefficients, their magnitudes being equal.

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.

Automatic Tuning Of Integrated Filters Using Neural Networks, Lutz Henning Lenz

Dissertations and Theses

Component values of integrated filters vary considerably due to· manufacturing tolerances and environmental changes. Thus it is of major importance that the components of an integrated filter be electronically tunable. The method explored in this thesis is the transconductance-C-method.

A method of realizing higher-order filters is to use a cascade structure of second-order filters. In this context, a method of tuning second-order filters becomes important.

The research objective of this thesis is to determine if the Neural Network methodology can be used to facilitate the filter tuning process for a second-order filter (realized via the transconductance-C-method). Since this thesis is, …

Unified Bias Analysis Of Subspace-Based Doa Estimation Algorithms, Yang Lu

Dissertations and Theses

This thesis presents the unified bias analysis of subspace-based DOA estimation algorithms in terms of physical parameters such as source separation, signal coherence, number of senors and snapshots. The analysis reveals the direct relationship between the performance of the DOA algorithms and signal measurement conditions. Insights into different algorithms are provided. Based upon previous first-order subspace perturbations, second-order subspace perturbations are developed which provide basis for bias analysis and unification. Simulations verifying the theoretical bias analysis are presented.

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.

A New Approach To The Optimal Filtering Of Differential Phase Measurements Of Gps Signal In The Precision Survey, Shengan Wang

Dissertations and Theses

The Global Positioning System (GPS) has become popular research and application interests in surveying and many other areas. Nowadays, the accuracy of the Differential GPS can easily reach the order of a few meters. Yet, there are still many ways to exploit the GPS system signal carrier to improve the accuracy to less than meter level. In this thesis, a new approach to improve the accuracy to less than meter level is presented while the observer is in the dynamic situation. In order to reach the sub-meter accuracy, we measure on the carrier phase difference (The L1 carrier frequency is …