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1991

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Full-Text Articles in Electrical and Computer Engineering

A Generalized, Parametric Pr-Qmf/Wavelet Transform Design Approach For Multiresolution Signal Decomposition, Hakan Caglar Dec 1991

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 …


Extension And Applications Of Knitting Technique For Petri Net Synthesis, Yanzhong Zhang Dec 1991

Extension And Applications Of Knitting Technique For Petri Net Synthesis, Yanzhong Zhang

Theses

Petri nets have been used for modeling and analyzing various systems [1,2,3,4,8]. One approach to Petri net synthesis is a knitting technique [4,5, 6,7]. It was developed for modeling concurrent systems. The Petri net model is incrementally expanded by adding paths of nodes according to rules. To extend the knitting technique to cover synchronized systems, a set of new rules based on synchronic distance concept is presented. The rules penult synchronizing M exclusive processes (M 2) to a synchronic distance of any positive integer N. They can be applied to both exclusive processes and independent processes. The resulting Petri net …


Computer Control For 2-Axis Magnetic Suspension System, Jian Chen Dec 1991

Computer Control For 2-Axis Magnetic Suspension System, Jian Chen

Theses

A two-axis magnetic suspension system. using linear-potentiometer position sensing and DC solenoids, controlled digitally by a 80386 microcomputer has been built and operated in our laboratory. Control algorithms obtained by combining the full-state feedback control law with two methods of estimating velocities are studied. One method uses a nonlinear reduced-order observer; the other uses a finite difference algorithm. The nonlinear reduced-order observer performs better in simulation but the difference algorithm takes less calculation time and is used in the implementation. The system has been operated successfully to suspend weights up to 1.2 lb. and to get a slant angle more …


Electrical Equivalent Method For The Calculation Of Vibrations In Transformers, D Chambega Dec 1991

Electrical Equivalent Method For The Calculation Of Vibrations In Transformers, D Chambega

Tanzania Journal of Engineering and Technology (TJET)

Noiselevel calculations may be done using an electrical equivalent method. So far a single mass and a double mass vibrating system may easily be represented by equivalent electrical circuits which are in turn useful for analysis. Multimass vibrating systems like transformers do not have straightforward methods which can enable analysis of noiselevels. This paper attempts to develop such a method by extending the method applicable to a double mass vibrating system. Then the validity of the method is tested using a transforme


Factors Affecting Capacity Utilization In Industries: Hierarchical Analysis, M Victor Dec 1991

Factors Affecting Capacity Utilization In Industries: Hierarchical Analysis, M Victor

Tanzania Journal of Engineering and Technology (TJET)

This paper provides a hierarchical analysis of the factors affecting capacity utilization in Tanzanian industries. Several factors were identified and sent to randomly selected industries in Tanzania for ranking. The collected data was summarized and analyzed. The analysis made use of a known procedure, the 'Analytical Hierarchy Process' (AHP). The final results shows a ranking of the factors, on various hierarchical levels as to their percentage contribution in lowering the capacity utilization.


Position Recovery And Motion Analysis From Stereo Image Sequences, Yuxin Xie Dec 1991

Position Recovery And Motion Analysis From Stereo Image Sequences, Yuxin Xie

Theses

Based on four stereo images, a new concept of unified optical flow field has been developed recently [3]. It is a generalization of the optical flow in stereo imagery. A set of fundamental equations is established to characterize the unified optical flow field. Another set of equations is then derived from which 3-D structure can be reconstructed and its motion can be analyzed by the use of the unified optical flow field quantities. In this thesis, we use some synthetic images of a rotated conical structure to study and test the theoretical results. The simulation and results are presented, thus …


An Implementation Of Bionomial-Qmf For Subband Coding Of Speech, Feng Chen Dec 1991

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 …


Minimum-Time Control For Submarine Interception, Zaiping Chen Dec 1991

Minimum-Time Control For Submarine Interception, Zaiping Chen

Theses

This thesis attempts to offer a possible improvement for conventional anti-submarine system which is mounted on warship. It consists of two parts: the control law and its realization concerning the particular problem. The control based on optimal theory is devised for three-dimentional minimum-time interception. A microprocessor system is also designed to achieve all necessary steps to track and attack the target. The thesis focuses on the question of how to launch a group of subcharges to destroy a submarine cruising under water: find the optimal trajectory by developing a numerical method to solve the nonlinear dynamic system and design a …


A Color Petri Net Simulation Tool, Sanjaykumar V. Desai Dec 1991

A Color Petri Net Simulation Tool, Sanjaykumar V. Desai

Theses

A user friendly, modular and highly interactive graphical tool for drawing, editing and simulating color Petri nets is developed. The tool is designed to model concurrent and interlocked systems, such as flexible manufacturing systems, communication protocols and computer systems. A Color Petri Net(CPN) has a more concise graphical system representation than a standard Petri net, because net entities in CPN carry information. The CPNS(Color Petri Net Simulation) tool simulates a net having conflicts, reveals deadlocks, and creates a log file with the state history of the system yielding performance measures.


Design Of An Advanced Control Algorithm For A Nuclear Power Plant Feedwater Control System, Randall C. Ezzo Dec 1991

Design Of An Advanced Control Algorithm For A Nuclear Power Plant Feedwater Control System, Randall C. Ezzo

Theses

Electric power companies with nuclear power plants have been aggressively looking for ways to increase plant safety and availability by increasing the reliability and performance of the plant's control systems. The performance of the Oyster Creek Nuclear Station's feedwater control system can be significantly improved by replacing the proportional-integral compensator with a compensator based on modern control concepts. In response to a -10 inch reactor water level setpoint change, settling time is improved from 107 seconds with 3% overshoot to 34 seconds with no overshoot.


Vision-Guided Servoing Robot Arm System, Shing Lee Dec 1991

Vision-Guided Servoing Robot Arm System, Shing Lee

Theses

This thesis investigate the problem of tracking 2-D circle parts with an eye-in-hand robot arm system. A vision module capable of measuring the motion of a circle is developed. Two algorithms based on the conic equation representation of circle and the symmetric property are developed. The first algorithm approximates the image of the circle as an ellipse. The second algorithm use the arc radius estimator to extract two image points of the circle located at the center of the largest arc. These image points are then used to solve for the inverse perspective transformation. An inverse kinematics solution based on …


Computer Aided Design Of A Broadband Microwave Power Divider, Jaideep Mukherjee Dec 1991

Computer Aided Design Of A Broadband Microwave Power Divider, Jaideep Mukherjee

Theses

The purpose of this thesis to provide alternative design procedure for a power divider that has broadband characteristics. The Wilkinson power divider consisting of cascaded quarter wave sections is known to increase the bandwidth while maintaining high isolation and good match conditions at individual ports. Resistors placed between the quarter wave sections served to increase isolation. The values of required components were determined using odd and even mode analysis. In this work, the approximate theory developed previously is used as a preliminary design model, and it is extended further by considering optimization techniques and coupling between adjacent arms. This novel …


Studying The Mechanical Response Of Outer Hair Cells To Electric Pulses Using Image Sensors, Wayel F. Mutlag Dec 1991

Studying The Mechanical Response Of Outer Hair Cells To Electric Pulses Using Image Sensors, Wayel F. Mutlag

Theses

The purpose of this research was to develop a way to improve the method used by Dr. Santos-Sacchi at the University of Medicine and Dentistry of New Jersey to detect the motion of the outer hair cell (OHC). As part of the work, the construction and functioning of the OHC are presented and two designs to detect the motion of the boundary of the OHC were investigated.

The first design utilizes the position sensitive detector (PSD) S3932 made by Hamamatsu Inc. This detector, however, required excessive intensity of the optical signal that was not compatible with the operation of the …


Realization Of High-Speed Carry Propagation For Addition And Multiplication Using The Redundant Binary System On The Mesh And Hypercube Connected Structures, Anil Rana Dec 1991

Realization Of High-Speed Carry Propagation For Addition And Multiplication Using The Redundant Binary System On The Mesh And Hypercube Connected Structures, Anil Rana

Theses

The extensive development of large-scale digital computers has naturally been accompanied by a corresponding development of techniques for fast arithmetic operations. Addition is the basis for the majority of the other arithmetic operations and most of the required time is due to carry propagation delay. Various algorithms have been proposed for fast addition and multiplication. The algorithms proposed here use the redundant binary system and are designed for the mesh structure. The algorithms are very efficient for the addition and multiplication of long operands. The algorithms can also be implemented on the hypercube. The n-dimensional hypercube is a highly concurrent …


Synthesis And Characterization Of Silicon Nitride Film Deposited By Plasma Enhanced Chemical Vapor Deposition From Ditertiary-Butyl Silane, Kei-Turng Shih Dec 1991

Synthesis And Characterization Of Silicon Nitride Film Deposited By Plasma Enhanced Chemical Vapor Deposition From Ditertiary-Butyl Silane, Kei-Turng Shih

Theses

Ditertiary-butyl silane (DTBS) and ammonia have been used to deposit silicon nitride films by plasma enhanced chemical vapor deposition (PECVD) with ammonia. The films were deposited in the temperature range of 150 to 300 °C with 0.15 watts/cm2 plasma power density at 100 KHz. The NH3/DTBS ratio was varied from 1 to 18, the total flow rate was varied between 195 and 570 sccm with total pressure ranging from 0.2 to 0.6 torr.

The deposition rate of these films was found to increase as total pressure or total flow rate increases, but was found to decrease as …


A Graphical Tool For The Simulation Of Timed Petri Nets, Javaid Aslam Siddiqi Dec 1991

A Graphical Tool For The Simulation Of Timed Petri Nets, Javaid Aslam Siddiqi

Theses

A highly interactive graphical tool is developed for the drawing and simulation of discrete event systems involving time constraints. The Timed Petri Net Simulator tool (TPNS) is capable of simulating systems with deterministic and stochastic delays. Performance and utilization parameters are collected during simulation for behavior and analysis purposes. Simulation results are stored in different files (log, verify, utilize, and mark). Conflict resolution on the basis of priority or random selection of multiple transitions in conflict is implemented to handle complex modeling situations. A user friendly interface is developed for effective interaction between the tool and the user. This interface …


Temperature Regulation Post Hemorrhagic Shock In Rats : Atheoretical Analysis, Kahambwe Shungu Dec 1991

Temperature Regulation Post Hemorrhagic Shock In Rats : Atheoretical Analysis, Kahambwe Shungu

Theses

The adequacy of a mathematical model in simulating temperature regulation in rats after resuscitation from hemorrhagic shock is investigated. This model, proposed elsewhere, was devised to study temperature profiles during hyperthermia in humans.

Hemorrhagic shock was achieved by bleeding rats to an average mean arterial pressure (MAP) of 30mmHg. The rats were then maintained at this MAP for up to four hours by withdrawing or reinfusing the shed blood. One group (the control group), was allowed to return to normal body temperature after the shock episode without external intervention. A second group (microwave group) was irradiated, for an average of …


Simulation And Modeling Of Kinetics Of Silicon Oxidation In The Thin Oxide Regime, Tirthankar Dutta Dec 1991

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 …


Error Detection And Correction In Compressed Data, Nadir Sezgin Dec 1991

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 Dec 1991

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 …


Conditional Artificial Dielectrics ; Fabry-Perot Etalon, Ling-Yi Hu Dec 1991

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.


Fast Arithmetic Operations On The Hypercube Using Conditional Sum Addition And Modified Booth's Algorithm, Umar Bin Iftikhar Dec 1991

Fast Arithmetic Operations On The Hypercube Using Conditional Sum Addition And Modified Booth's Algorithm, Umar Bin Iftikhar

Theses

Algorithms for fast arithmetic operations (i.e., addition and multiplication) on the hypercube computer are presented. The hypercube network of dimension d interconnects N = 2d processors in such a way that each processor is directly connected to d neighboring processors; m order to communicate between processors, the maximum length of the path is d. The addition algorithm is based on the conditional sum technique. The computational time using this algorithm is O(log2 N+q) where q is the number of the bits per processor in the hypercube of N processors. Operands of size N*q are distributed among the hypercube …


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 Dec 1991

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.


Ignoring Interprocessor Communication During Scheduling, Chintamani M. Patwardhan Dec 1991

Ignoring Interprocessor Communication During Scheduling, Chintamani M. Patwardhan

Dissertations and Theses

The goal of parallel processing is to achieve high speed computing by partitioning a program into concurrent parts, assigning them in an efficient way to the available processors, scheduling the program and then executing the concurrent parts simultaneously. In the past researchers have combined the allocation of tasks in a program and scheduling of those tasks into one operation. We define scheduling as a process of efficiently assigning priorities to the already allocated tasks in a program. Assignment of priorities is important in cases when more than one task at a processor is ready for execution. Most heuristics for scheduling …


A Multiple Coupled Microstrip Transmission Line Model For High-Speed Vlsi Interconnect Simulation, Lawrence Stevan Uzelac Dec 1991

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 be 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 …


Method For Gaseous Component Indentification With #3 Polymeric Film, Edward S. Kolesar Jr. Dec 1991

Method For Gaseous Component Indentification With #3 Polymeric Film, Edward S. Kolesar Jr.

AFIT Patents

A sensor having an interdigitated gate electrode field effect transistor (IGEFET) coupled to an electron beam evaporated copper phthalocyanine thin film is used to selectively detect parts-per-billion concentration levels of atmosphere contaminants such as nitrogen dioxide (NO2) and diisopropyl methylphosphonate (DIMP). The sensor is excited with a voltage pulse, and its time- and frequency-domain response are examined. The envelopes of the magnitude of the normalized difference frequency spectrums reveal features which unambiguously distinguish the NO2 and DIMP exposures.


Spectral And Spatial Quantum Efficiency Of Algaas/Gaas And Ingaas/Inp Pin Photodiodes, Steven Alan Tabor Dec 1991

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 …


Composite Damage Assessment Employing An Optical Neural Network Processor And An Embedded Fiberoptic Sensor Array, Barry G. Grossman, Xing Gao, Michael H. Thursby Dec 1991

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 …


A Rigorous Utd Analysis Of Electromagnetic Scattering From Resistive Strips And Resistive-Loaded Conducting Strips, Douglas H. Casanova Dec 1991

A Rigorous Utd Analysis Of Electromagnetic Scattering From Resistive Strips And Resistive-Loaded Conducting Strips, Douglas H. Casanova

Theses and Dissertations

This thesis investigates electromagnetic scattering from resistive strips and resistive-loaded conducting strips using a rigorous UTD formulation. The UTD diffraction coefficients are based on the Wiener-Hopf technique and Jones' method. Scattering predictions are performed for constant resistive strips, constant resistive-loaded conducting strips, tapered resistive strips, and tapered resistive-loaded conducting strips. All strip geometries have a total width of 4 lambda. Predictions are compared to method of moments (MM) and measurements to determine the validity of the UTD prediction. Overall, there is good agreement. For TMz polarization the only deviations that occur with MM are near edge-on when the degree of …


Neural Control Of Smart Electromagnetic Structures, Michael Thursby, Kisuck Yoo, Barry G. Grossman Dec 1991

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 …