Engineering Commons^™

A Generalized, Parametric Pr-Qmf/Wavelet Transform Design Approach For Multiresolution Signal Decomposition, Hakan Caglar

Dissertations

This dissertation aims to emphasize the interrelations and the linkages of the theories of discrete-time filter banks and wavelet transforms. It is shown that the Binomial-QMF banks are identical to the interscale coefficients or filters of the compactly supported orthonormal wavelet transform bases proposed by Daubechies.

A generalized, parametric, smooth 2-band PR-QMF design approach based on Bernstein polynomial approximation is developed. It is found that the most regular compact support orthonormal wavelet filters, coiflet filters are only the special cases of the proposed filter bank design technique.

A new objective performance measure called Non-aliasing Energy Ratio(NER) is developed. Its merits …

Error Detection And Correction In Compressed Data, Nadir Sezgin

Theses

Encoded data is very sensitive to the channel errors. Especially if the data is compressed by Arithmetic Encoding procedure, then the error propagation is very high. The error propagation in Arithmetic Coding is studied. Exploiting the high error propagation property when compressing data by Arithmetic encoding procedure, two different algorithms have been proposed for error detection and correction. Under certain conditions these algorithms detect and with a very high probability correct the errors introduced to the compressed data.

Software Development For Analysis Of Stochastic Petri Nets Using Transfer Functions, Aman U. Jamwal

Theses

This thesis research is an implementation of a closed-form analytical technique for study, evaluation and analysis of Stochastic Petri Nets (SPN). The technique is based on a theorem that an isomorphism exists between an SPN and a Markov Chain. The procedure comprises five main steps: reachability graph generation of the underlying Petri net, transformation of the reachability graph to a state machine Petri net, calculation of transfer functions, computation of equivalent transfer functions via Mason's rule, and computation of performance parameters of the SPN model from the equivalent transfer functions and their derivatives. The software is developed in UNIX using …

Simulation And Modeling Of Kinetics Of Silicon Oxidation In The Thin Oxide Regime, Tirthankar Dutta

Theses

Thermal oxidation of Silicon in dry O₂, in the thin regime(< 500A) is of vital importance to VLSI device engineers, because thin layers of SiO₂ are exclusively used as gate dielectric for high performance of MOS devices. There exist a number of models to explain the kinetics of oxidation in this thin regime. However there is considerable variance among them and the reported rate constants, which are supposed to describe the oxidation process. Rather than arriving at an alternative model, the present study aims at an extensive study and simulation of existing models of oxidation in dry oxygen, in the thin regime, with a recent set of experimental data and …

Conditional Artificial Dielectrics ; Fabry-Perot Etalon, Ling-Yi Hu

Theses

Fabry-Perot etalons are optical resonators comprise of two mirrors and a spacer layer. By embedding a thin, photo-sensitive layer ( Conditional Artificial Dielectric - CAD layer ) in the middle of the spacer layer, we were able to photo-control the transmission properties of a Fabry-Perot etalon. Different structures have been analyzed and measured to find that a change of .01 was photo-activated in the refractive index of the Conditional Artificial Dielectric layer.

An Implementation Of Bionomial-Qmf For Subband Coding Of Speech, Feng Chen

Theses

A real-time subband speech codec is implemented by the author on TMS320C25 digital signal processor based hardware for speech compression down to 0.25 bit per sample.

The Binomial Quadrature Mirror Filters (B-QMFs) are employed as the basic block for the hierarchical, dynamic tree, analysis/synthesis filter bank. After the analysis, available bits are optimally allocated among subbands. Band statistics are updated to overcome the nonstationarities of speech signal.

The energy compaction performance of this codec is compared with different subband and DCT in simulations for speech signals and AR(1) source models.

It is shown that the speech codec implemented provides an …

Comparison Of Timing Jitter In External And Monolithic Cavity Mode-Locked Semiconductor Lasers, Dennis J. Derickson, P. A. Morton, J. E. Bowers, R. L. Thornton

Electrical Engineering

A comprehensive timing jitter comparison is made for mode-locked semiconductor lasers using active, passive, and hybrid mode-locking techniques in both external and monolithic cavity configurations. Active mode locking gives the lowest residual rms timing jitter of 65 fs (150 Hz-50 MHz), followed by the hybrid and passive mode-locking techniques. It is found that monolithic cavity devices with all active waveguides have higher timing jitter levels than the comparable external cavity case.

A Multiple Coupled Microstrip Transmission Line Model For High-Speed Vlsi Interconnect Simulation, Lawrence Stevan Uzelac

Dissertations and Theses

A model is presented which incorporates the advantages of a mixed mode simulation to characterize transmission line behavior in multiple coupled Transmission line systems. The model is intended for use by digital circuit designers who wish to be able to obtain accurate transmission line behavior for complex digital systems for which continuous time simulation tools such as SPICE would time prohibitive. The model uses a transverse electromagnetic wave approximation to obtain solutions to the basic transmission line equations. A modal analysis technique is used to solve for the attenuation and propagation constants for the transmission lines. Modal analysis done in …

Spectral And Spatial Quantum Efficiency Of Algaas/Gaas And Ingaas/Inp Pin Photodiodes, Steven Alan Tabor

Dissertations and Theses

This thesis reports a novel system capable of testing both the spectral responsivity and the spatial quantum efficiency uniformity of heterostructure photodiodes using optical fiber coupled radiation. Testing was performed to confirm device specifications. This study undertakes to quantify the spectral bandwidth of an AlGaAs I GaAs double heterostructure photodiode and two InGaAs I InP double heterostructure PIN photodiodes at D.C., through the use of spatial scanning. The spatial scanning was done using lasers at 670 nm, 780 nm, 848 nm, 1300 nm, and 1550 nm, coupled through singlemode optical fiber. The AlGaAs I GaAs material system covers the 600 …

Neural Control Of Smart Electromagnetic Structures, Michael Thursby, Kisuck Yoo, Barry G. Grossman

Electrical Engineering and Computer Science Faculty Publications

Artificial neural networks (ANNs) and their ability to model and control dynamical systems for smart structures, including sensors, actuators, and plants, are directly applicable to the smart electromagnetic structures (SEMS) concept. The application of neural networks to the area of controls is being reported frequently. The ability of a structure to adapt to impinging electromagnetic (EM) energy will allow the structure to change its reflection characteristics and thus to change its radar signature. By embedding a control element in the structure of a single microstrip patch element, its electrical characteristics can be changed. If such an element can be controlled …

Composite Damage Assessment Employing An Optical Neural Network Processor And An Embedded Fiberoptic Sensor Array, Barry G. Grossman, Xing Gao, Michael H. Thursby

Electrical Engineering and Computer Science Faculty Publications

This paper discusses a novel approach for composite damage assessment with potential for DoD, NASA, and commercial applications. We have analyzed and modeled a two dimensional composite damage assessment system for real-time monitoring and determination of damage location in a composite structure. The system combines two techniques: a fiberoptic strain sensor array and an optical neural network processor. A two dimensional fiberoptic sensor array embedded in the composite structure during the manufacturing process can be used to detect changes in the mechanical strain distribution caused by subsequent damage to the structure. The optical processor, a pre-trained Kohonen neural network, has …

Electrical Characterization Of Metal‐Insulator‐Semiconductor Diodes Fabricated From Laser‐Ablated Yba2Cu3O7−Δ/Yttria‐Stabilized Zirconia Films On Si Substrates, Eric M. Ajimine, Felino E. Pagaduan, M. Mahmudur Rahman, Cary Y. Yang

Electrical and Computer Engineering

The purpose of this investigation is to study the electrical properties of the YBCO/YSZ/Si metal‐insulator‐semiconductor structure and the yttria‐stabilized zirconia (YSZ)/Si interface. The YBCO and YSZ layers were epitaxially grown in situ on Si by pulsed laser deposition. Current‐voltage measurements of devices fabricated on p‐type Si(100) showed a small leakage current density at 292 K, which decreased further at 80 K. Comparison of capacitance‐voltage measurements at 292 K for frequencies between 10 and 400 kHz showed a large variation of capacitance in the accumulation region demonstrating the presence of mobile ions in the YSZ layer. This variation is less pronounced …

Comparison Of Spice And Network C Simulation Models Using The Cam System, Wen-Tsung Yen

Dissertations and Theses

The performance of SPICE and Network C (NC) circuit simulator when simulating MOS transistor circuits has been investigated and compared. SPICE analog model, NC analog model and NC MOS_PWL model are the three MOS transistor models being used. The comparison between SPICE and NC includes five areas. They are MOS transistor model, circuit analysis and computational methods, limitation on the ability to simulate circuits containing the MOS transistor diode configuration, run time and the ability to build new circuit component models using derived equations.

The prototype circuit being used is the Content-Addressable Memory (CAM) circuit. The CAM circuit is a …

Improved Efficiency In Semiconducting Polymer Light-Emitting Diodes, David Braun, A. J. Heeger, H. Kromer

Electrical Engineering

We report visible light emission from metal-polymer diodes made from semiconducting polymers, with indium-tin oxide as the “ohmic” contact, and a variety of metals as the barrier metal. Our results, which confirm the discovery by the Cambridge group [Nature347, 539 (1990)], demonstrate that light-emitting diodes can be fabricated by casting the polymer film on indium-tin oxide from solution with no subsequent polymer processing or heat treatment required. Electrical characterization reveals diode behavior with rectification ratios greater than 105 at sufficiently high voltages. Use of an electrode material with low work function leads to more than an order of magnitude improvement …

Detection Of Unresolved Target Tracks In Infrared Imagery, Sarah A. Rajala, Loren W. Nolte, James V. Aanstoos

Sarah A. Rajala

Two methods for detecting dim, unresolved target tracks in infrared imagery are presented. Detecting such targets in a sequence of noisy images is very challenging from the standpoint of algorithm design as well as detection performance evaluation. Since the signal-to-noise ratio per pixel is very low (a dim target) and the target is unresolved (of spatial extent less than a pixel), one must rely on integration over target tracks which span over many image frames. In addition, since there is a large amount of uncertainty as to the pattern and location of target tracks, good algorithms must consider a large …

A Note On Repeated-Root Cyclic Codes, Robert H. Morelos-Zaragoza

Faculty Publications

In papers by Castagnoli et al. and Van Lint, cyclic codes with repeated roots are analyzed. Both papers fail to acknowledge a previous work by Chen, dating back to 1969, which includes an analysis of even, length binary cyclic codes. Results from Chen’s study are presented.

Analysis Of Baseband Equivalent Noise In A First-Order Correlation Loop Utilizing Filtered Pseudonoise Signals, Kurt Louis Kosbar, Christopher J. Scholten

Electrical and Computer Engineering Faculty Research & Creative Works

Conventional direct-sequence and frequency-hopping spread spectrum systems utilize delay-lock loops to track the timing epoch of pseudonoise codes. These devices perform admirably at high signal-to-noise ratios (SNR), however, they are suboptimal at moderate and low SNR. A correlation loop that employs appropriately filtered pseudonoise signals for the local cross-correlation waveform may have superior performance under these conditions. The performance of this modified correlation loop will be determined by the cross correlation function of the transmitted waveform and locally generated reference signals, along with the statistics of the baseband equivalent noise process. In this work, we find the statistics of the …

Detection Of Unresolved Target Tracks In Infrared Imagery, Sarah A. Rajala, Loren W. Nolte, James V. Aanstoos

James Aanstoos

Two methods for detecting dim, unresolved target tracks in infrared imagery are presented. Detecting such targets in a sequence of noisy images is very challenging from the standpoint of algorithm design as well as detection performance evaluation. Since the signal-to-noise ratio per pixel is very low (a dim target) and the target is unresolved (of spatial extent less than a pixel), one must rely on integration over target tracks which span over many image frames. In addition, since there is a large amount of uncertainty as to the pattern and location of target tracks, good algorithms must consider a large …

Direct Recovering Of Surface Structure Characterized By An Nth Degree Polynomial Equation Using The Uoff Approach, Mazen A. Salhi

Theses

There are two different approaches for estimation of structure and/or motion of objects in the computer vision community today. One is the feature correspondence method, and the other is the optical flow method [1]. There are many difficulties and limitations encountered with the feature correspondence method, while the optical flow method is more feasible, but requires a substantial amount of extra calculations if the optical flow is to be computed as an intermediate step.

Direct methods have been developed [2-4], that use the optical flow approach, but avoid computing the full optical flow field as an intermediate step for recovering …

Instrumentation And Control For A Microprocessor-Based Coronary Perfusion System, Daniel L. Priester

Master's Theses (1922-2009) Access restricted to Marquette Campus

No abstract provided.

Temperature Dependence Of Optical Properties Of Gaas, Huade Yao, Paul G. Snyder, John A. Woollam

Department of Electrical and Computer Engineering: Faculty Publications

Pseudodielectric functions (ε) = (ε₁) + i (ε₂) of GaAs were measured by spectroscopic ellipsometry (SE), in the range of 1.W.45 eV, at temperatures from room temperature (RT) to ~610 ° C. A very clean, smooth surface was obtained by first growing an epitaxial layer of GaAs on a GaAs substrate and immediately capping it with a protective layer of arsenic. The cap prevented surface oxidation during transport to the measurement chamber, where it was evaporated under ultrahigh vacuum at ~350 °C. Room-temperature SE results from this surface are in good agreement with those in the …

Field-Equation Approximations And Amplification In High-Gain Lasers: Numerical Results, Lee W. Casperson

Electrical and Computer Engineering Faculty Publications and Presentations

It has recently been shown that a field-equation time-derivative approximation that is commonly used in studies of laser-oscillator dynamics is not necessary and can lead to significant errors for some lasers. A related space-derivative approximation is widely used in studies of steady-state laser amplifiers. A more rigorous amplifier formalism is developed here, and the results are exact solutions of Maxwell’s equations. The improved model predicts a spatial instability, single mirror oscillation, and other interesting field behavior.

Field-Equation Approximations And Amplification In High-Gain Lasers: Analytical Results, Lee W. Casperson

Electrical and Computer Engineering Faculty Publications and Presentations

In a related study the equations governing a high-gain laser amplifier have been solved numerically without making the usual slowly-varying-amplitude derivative approximation in Maxwell’s equations, and thus the field amplitudes are not restricted to vary negligibly in a distance of one wavelength. The results reveal an instability that involves reflections and oscillatory growth of perturbations away from steady state. In the present study steady-state solutions of the field equations are obtained analytically, and transformations are described for converting the equations to alternative intensity-equation sets. These intensity equations are linearized and solved for the growth rate and oscillation period of the …

Efficient Single-Heterojunction Al0.27Ga0.73As/Gaas P-I-N Photodiodes With 22-Ghz Bandwidths, C. Johnson, S. Sloan, D. M. Braun, J. L. Russell, M. Zurakowski, M. Lightner, F. Kellert, G. Patterson, R. Koo, Dennis J. Derickson, J. E. Bowers

Electrical Engineering

A report is presented on the design, fabrication, testing, and modeling of single-heterojunction Al_0.27Ga_0.73As/Ga p-i-n photodiodes for use as components in optical receivers. The photodiodes are grown by molecular beam epitaxy and fabricated as 1100-μm² mesa structures. At 5-V reverse bias and 850 nm, 100 fF of capacitance, 90 pA of leakage current, 73% external quantum efficiency, <2% reflectivity, and 22-GHz bandwidths are typically measured.

Electromagnetic Field Plot Of An Inductive Window By The Moment Method, John R. Natzke, Mark R. Wolski, Thomas Koryu Ishii

Faculty Publications - Department of Electrical Engineering and Computer Science

A moment method is used to plot the electromagnetic field of an inductive window in a TE10 -mode rectangular waveguide. Green's dyadic functions are derived based on Tai's approach, which is a modified form of Hansen's vector wave functions. Based on the computed electric fields, the S matrix and the equivalent aperture reactance of the waveguide window are calculated. This calculation agrees with the previously published closed-form results of Marcuvitz.

Inhibited Spontaneous Emission By Photonic Band Gaps In A Square Lattice Of Periodic Dielectric Medium, Abdullah Al-Ghamdi

Masters Theses

The concepts of band theory for electrons can be employed to describe the behavior of electromagnetic waves propagating in two-dimensional, periodic dielectric structures. These two-dimensional, periodic structures can produce photonic band gaps in which the spontaneous emission by atoms embedded in the structure is prohibited and as a result the performance of many semiconductor devices can be enhanced. The calculations are based on finding the eigenvalues of the algebraic equation for the frequencies of electromagnetic waves moving in a square lattice composed of square dielectric rods with different dielectric constants.

Associative Processing Implemented With Content-Addressable Memories, Luis Sergio Kida

Dissertations and Theses

The associative processing model provides an alternative solution to the von Neumann bottleneck. The memory of an associative computer takes some of the responsibility for processing. Only intermediate results are exchanged between memory and processor. This greatly reduces the amount of communication between them. Content-addressable memories are one implementation of memory for this computational model. Associative computers implemented with CAMs have reported performance improvements of three orders of magnitude, which is equivalent to the performance of the same application running in a conventional computer with clock frequencies of the order of GHz. Among the benefits of content-addressable memories to the …

Computer-Based Parameter Visualization And Decision Making For The Detection And Prediction Of Ovulation: The Ovulo-Computer, Omar Rodolfo Bermudez

Dissertations and Theses

It is now well accepted by gynecologists that a woman can conceive from an act of intercourse for a maximum of seven days of her menstrual cycle [1]. The reliability of natural family planning methods depends on identifying this window of fertility without ambiguity. Several natural family planning (NFP) methods have been used extensively and with some success. For decades, cycle length and BBT history have been used to forecast the most likely days of ovulation. When greater precision is needed, serum LH assays or ultrasound techniques are used. With the recent development of enzyme-linked immunosorbent assay, various kits have …

Transmission Ellipsometry On Transparent Unbacked Or Embedded Thin Films With Application To Soap Films In Air, R. M.A. Azzam

Electrical Engineering Faculty Publications

The ratio ρ_t = T_p/T_s of the complex amplitude transmission coefficients for the p and s polarizations of a transparent unbacked or embedded thin film is examined as a function of the film thickness-to-wavelength ratio d/λ and the angle of incidence Φ for a given film refractive index N. The maximum value of the differential transmission phase shift (or retardance), Δ_t = argρ_t, is determined, for given N and Φ, by a simple geometrical construction that involves the iso-Φ circle locus of ρ_t in the complex plane. The …

A Robust Approach To Human-Computer Interface Design Using The Taguchi Method, Billie Mitchell Reed

Engineering Management & Systems Engineering Theses & Dissertations

The application of Dr. Genichi Taguchi's approach for design optimization, called Robust Design, to the design of human-computer interface software is investigated. The Taguchi Method is used to select a near optimum set of interface design alternatives to improve user acceptance of the resulting interface software product with minimum sensitivity to uncontrollable noise caused by human behavioral characteristics.

Design alternatives for interaction with personal micro-computers are identified. Several important and representative alternatives are chosen as design parameters for the Taguchi matrix experiment. A noise field with three human behavioral characteristics as noise factors were chosen as a representative noise array. …