Electrical and Electronics Commons^™

Design Of A Microengineered Pressure Sensor, Ranjeet Alexis

Theses

A new family of microengineered vacuum ionization gauges of an approximate volume of 200µ³ has been designed. These devices can he fabricated using existing semiconductor processing capabilities. The focus of this thesis is to scale down the current state-of-the-art for ionization sensors to micron dimensions. These gauges can be manufactured economically and potentially will be integrated with more complex structures and circuitry. In these devices an active ionization volume of micron dimensions is used for launching ions in a trajectory towards a collection electrode. Ionization of gas species is accomplished by an electron flux of sufficient energy. Analysis of …

Point Pattern Matching By A Genetic Algroithm, Minghwang Chen

Theses

The problem we consider is to find a subset of points in a pattern that best match to a subset of points in another pattern through a transformation in a least squares sense. Exhaustive search to find the best assignment mapping one set of points to another set is, if the number of points that are to be matched is large, computationally expensive. We develop a genetic algorithm which searches for the best ("almost the best") assignment efficiently. To map the point pattern matching into the framework of a genetic algorithm, we use a fitness function which inversely proportional to …

Decomposing Non-Product Form Queuing Lattices Through Genetic Algorithm, Wei Han

Theses

In this paper, a Genetic Algorithm technique is adapted to decompose the state transition lattice of a class of non-product form queueing models. Genetic Algorithms are search algorithms based upon the mechanics of natural genetics. They combine a survival-of-the-fittest among string structures with a structured, yet randomized, information exchange to form a search algorithm with some of the innovative flair of human search. While randomized, genetic algorithms are no simple random walk. They efficiently exploit historical information to speculate on new search points with improved performance. Here genetic algorithms is applied to a non-product queueing lattices optimization problem. Only the …

Performance Evaluation Of Consumer Electronic Bus, Sairaj R. Pakkam

Theses

This thesis describes the performance evaluation of the Consumer Electronic Bus proposed by the Electronic Industries Association. To study the behaviour of CEBUS under different traffic conditions, a simulation program was developed modelling the layer architecture of CEBUS. The CEBUS is based on the ISO/OSI model of layered architecture. The simulation results have shown that, when the throughput of the network is small, the delay is bounded for all messages of all priorities. As the throughput of the network increases, under the presence of more high priority messages, the lower priority messages get queued at their nodes. It is also …

Conditional Artificial Dielectric Waveguide, Hsien-Wen Ho

Theses

A thin layer of semiconductor ( the guest material ) is sandwiched between two polymeric films ( the host material ) to form an artificial dielectric waveguide. An artificial dielectric is a composite material consisting of a dielectric with a large number of conducting particles arranged in a three-dimensional pattern. The particle dimensions are smaller than the optical wavelength of interest. A beam of light with a photon energy above the band-gap of the semiconductor ( pump light ) induces electric and magnetic dipoles which affect the propagation of light with a photon energy below the band-gap ( probe light …

Hardware Algorithms For Computing Transcendental Functions, Xin-Pei Gong

Theses

The COordinate Rotation Digital Computer(CORDIC) is a special-purpose digital computer for real-time airborne computation. In this computer, a unique computing technique is employed which is especially suitable for solving the trigonometric relationships. A new computing technique based on the CORDIC algorithm is developed to reduce the number of iterations by one half for each input angle. This improvement is accomplished. by scanning multiple bits of the input angle(in our case, two) at a time. The CORDIC equations are rewritten accordingly and a hardware implementation structure is also presented. The results of the software simulation of the new algorithm are as …

Damage Effects To Si-Sio2 Structures Due To Reactive Ion Etching, Moshe D. Bunyan

Theses

This thesis presents the damage effects to the Si ? SiO₂ structures due to Reactive Ion Etching (RIE). The research was carried out on Si ? SiO₂ MOS capacitors which were fabricated using RIE and wet etch (Hydrofluoric acid etch (HFE)) Process. The experiment was carried out using CV technique and Ellipsometry. Various electrical parameters were measured from CV *curves of these MOS capacitors. It was observed that the CV curve obtained for the RIE etched sample showed considerable deviation from that of the control sample. This indicates the presence of excess of interface trap charge density which …

Improving Solids Conveying In Plasticating Extruders : An Investigation Into Manufacturing Processes And Manufacturing Systems For Profiled Thermoplastic Pellets, Oommen Cherian

Theses

The objective of the thesis is the manufacture of thermoplastic bilobal and trilobal profiled pellets for the determination of the interparticulate co-efficient of friction exhibited by solid beds of such pellets. The enhancement of the interparticulate coefficient of friction is expected to lead to ameliorated solids conveying rates in plasticating extruders.

Predicting the product shape from a profile die is very difficult due to the elastic memory of plastics and the complex boundary conditions. Consequently the cost involved in experimenting with different profile dies is high. Therefore a standard die with several die inserts of varying cross-sections were used to …

Small Disturbance Stability As Affected By Excitation Controls, Alfredo Flores

Theses

The effect of excitation control systems on the power system's small disturbance stability limits has been investigated in this thesis. Three excitation control schemes namely the proportional, fast?acting and the modified fast?acting have been studied.

The stability results were predicted directly in terms of the AVR gain controlling parameters following one?dimensional and two?dimensional frequency domain separation technique. The necessary algorithms and computer simulation programs have been developed.

In case of a modified fast?acting excitation control with three unknown variables, a procedure has been proposed to obtain the stability results by extending the two?dimensional frequency domain separation technique.

Effect Of Moisture On Microcircuit Failure, Chandrabala D. Patel

Theses

Stability and reliability of microcircuit is dependent on its design, fabrication, testing, storage and use.

In this thesis emphasis is given on various failure mechanisms of Integrated Circuits in humid environment and techniques of improving reliability. Other factors which affect the failure of integrated circuits are also discussed. Moisture induced failure modes, semi-reversible failures and irreversible failures (surface leakage current and corrosion-causing interruption of interconnection lines) are also reviewed.

Controlling the contaminants and moisture related corrosion are also covered. The quickest way to evaluate the reliability of microcircuit is by accelerated aging test and by selection of meaningful criteria of …

Computer Aided Localization Of Neurological Diseases, Yusuf Parlar

Dissertations

Computers in medicine has brought new dimensions and better understanding of uncertainties in the field of medical sciences in the last decade. This thesis is focused upon the localization of neurological lesions in the human nervous system. It relates clinical neurological test outcomes to pathways of function or malfunction. Certain methods are proposed-empirical. stochastic. Deterministic-to estimate the spatial distributions of lesion probabilities.

First. a Bayesian model is presented to estimate the posterior probability of lesion from a priori information, based on the test outcomes. Due to unavailable data alternative methods and models are presented: Regression Analysis. Monte Carlo simulation, and …

On The Performance Of Minimum Redundancy Array For Multisource Direction Finding, Byung-Seub Lee

Dissertations

As an application of power spectrum estimation, the multi-source direction finding has been evolved from conventional FFT method to Superresolution methods such as Multiple Signal Classification(MUSIC) algorithm. Uniform Regular Array(URA) was mainly used in all these approaches.

The Minimum Redundancy array(MRA); a non-uniform thinned array which results in an input signals covariance matrix with minimum redundancy has been shown to have certain interesting properties for spectrum estimation. Only recently it was suggested to use the MRA for spatial estimation. The purpose of this research was to study the performance of this array in multi-source direction finding estimation and compare it …

Computer Modeling And Analysis Of Biological Rhythms, Shi Xiong Yang

Dissertations

Biological rhythms are an important phenomenon and feature of physiologic systems. Indirect means have to be employed for their description and exploration due to the unclear internal nature of the system. This study analyzed and developed several possible mathematical models using single or multidimensional nonlinear differential equations to approach the experimental circadian data. The numerical solutions of the models were obtained by computer simulation and the simulated and experimental acquired circadian data were analyzed in both the time and frequency domains. Phase plane plots, phase response curves and power spectrum analysis were employed to determine the nonlinearity of the system …

Interconnection Of X.25 Networks, Syed Ayaz Qutubuddin Ahmed

Theses

The purpose of this work was to investigate the performance of two interconnected X.25 networks via CCITT internet protocol X.75. Since internet protocol X.75 follow the same flow approach as X.25, we are allowed to model the acknowledgement queue in such a way that this queue provides a feed back path from destination to the source queue. Thus we are able to model our interconnected network as a closed queueing network with limited number of packets in transit within the network. Mean Value Analysis with Blocking (MVA) algorithm was applied to obtain the performance characteristics as the resources available were …

An Implementation Of Mht Algorithm For Adaptive Transform Coding Of Speech, Peter Battenschlag

Theses

The Modified Hermite Transform (MHT), a suboptimum block transform scheme, is implemented on a TMS320C25 signal processing system with the objective of reducing the redundancy in speech signals and transmit a quantized vector representation at bitrates as less as 0.5 bits per sample.

The generation of the Hermite polynomials with a binomial and several first order IIR filter structures is presented focusing on the fact that no muliplications are required which simplifies the MHT algorithm considerably.

An assembler program performs forward and inverse transformation together with a vector quantization using adaptive bitallocation based on short-time statistics for the transform coefficients. …

Multichannel Input Moniter, Geng Lin Chen

Theses

In order to communicate ,with each other, people must use the same kind of language. MIDI, the Musical Instrument Digital Interface, was established as a hardware and software specification which makes the communication between musical instruments become possible.

What this thesis does is interfacing a musical instrument with other devices using MIDI protocol. The hardware is a multichannel priority interrupt system which has already been done and was included in the discussion of this thesis. The focus of this thesis is concentrated on the software development of multichannel input monitor.

Configuring Maps For A Satellite Communication Network By Self- Organization, Yizhong Chen

Theses

There are several management tasks in a telecommunication network. Among which traffic management is one of the most important and difficult tasks. It is concerned with maximizing network efficiency when the network is under stress either due to overload or failure. New attempts to automate this task such as expert system based approach are yet to be perfected. In this thesis, we advocate a new concept of traffic management. Our scheme consists of two levels. At the first level, we introduce a Self-organization model to dynamically configure a map for a satellite communication network. The second level is a routing …

A Micro-Based Machine Vision System, Hsueh-Chung Michael Feng

Theses

In this thesis, a low-cost general purpose machine vision system based on a personal computer of the PC-XT/AT family and an electronic camera controller based upon a Motorola 6811C11 single-chip microcontroller has been designed and implemented. This work is focused on image formation. The system supports a long distance camera-computer configuration. A picture editor, generic image manipulation software was designed and implemented. A single computer can supervise multiple cameras.

Analysis Of The Effects Of Biofeedback On Cardiovascular And Neuromuscular System, Andreas T. Gikas

Theses

Time series signal processing techniques (Fourier based) were applied to study the effects of biofeedback on the cardiovascular and neuromuscular system.

A medical instrumentattion system was developed to monitor ECG, EEG and EMG biopotential signals and temperature.

Data from two experiments were first analyzed. These data were from two normal male subjects who engaged in relaxation techniques (Transcendental Meditation & Imagery). If we assumed that for both subjects relaxation produced a decrease of the sympathetic activity then that resulted in a decrease of the heart rate (ECG) and an increase in skin temperature. Spectral analysis of the EEG signal showed …

Reliability Of Titanium Dioxide Capacitors, Md. Badrul Hasan

Theses

In recent years many different materials have been investigated as potential thin-film capacitor dielectrics. Silicon monoxide (SiO) and tantalum pentoxide (Ta₂O₅) are the two dielectric materials that are being used by most companies.

This thesis provides some theory and experiments to evaluate the reliability of TiO₂ as a material which would yield a dielectric constant much higher than Ta₂O₅. It has also been shown that titanium dioxide is economically and technically capable of miniaturization demanded by the latest electronic systems.

Included here are the sections covering evaporant materials and their purities, …

An Artificial Neural Network For Redundant Robot Inverse Kinematics Computation, Wibawa Utama

Theses

A redundant manipulator can be defined as a manipulator that has more degrees of freedom than necessary to determine the position and orientation of the end effector. Such a manipulator has dexterity, flexibility, and the ability to maneuver in presence of obstacles. One important and necessary step in utilizing a redundant robot is to relate the joint coordinates of the manipulator with the position and orientation of the end-effector. This specification is termed as the direct kinematics problem and can be written as x = f(q)
where x is a vector representing the position and orientation of the end-effector, q …

Design And Analysis Of Movable Boundary Allocation Protocol, Karun Sekhri

Theses

The increasing digital communications traffic will require very high speed networks. The use of high communication speed increases the ratio between end to end propagation delay and the packet transmission time. This increase causes rapid performance deterioration and restricts the utilization of the high system bandwidth in broadcast channel based systems. Using several parallel channels in place of a single channel improves this ratio. For a given system bandwidth the total system capacity is increased by bandwidth division and parallel communication. FTDMA protocols have been suggested for the parallel channel network and these protocols are suitable for different loads. In …

Control Of Stress In Silicon Nitride Thin Films, Ajay Krishnan

Theses

Silicon nitride thin films of varying composition and thickness were deposited on silicon substrates by reactive rf diode sputtering of a silicon target using an argon/nitrogen gas mixture. Film stoichiometry could be controlled by varying the partial pressure of nitrogen, the total sputtering gas pressure and the target rf power. Films with refractive index of 2.01, the value for stoichiometric silicon nitride, could be obtained. Film stress was measured by wafer curvature; refractive index and thickness of deposited films were obtained by ellipsometry and interferometry measurements. The etch rate in buffered HF for films with refractive index 2.05 was 29A/min; …

Multiprocessor System Design Tutor : Expert System Approach, Rakesh Kamdar

Theses

To increase computational bandwidth and system resilience, integration of several microprocessors in a single system becomes necessary. The overall throughput and efficiency of such a system is directly dependent on the hardware and software interconnection supported by the basic microprocessor chip. Sometimes it becomes difficult to put together all the information for design criteria and all the design related formulas.

The approach made here is to continuously update the hardware and software information in the database related to a given microprocessor. This information can be accessed at any time for efficient design solution. Intel 80386 and Motorola 68020 microprocessors are …

A Study Of The Effects Of Weighting Matrices In Power System State Estimation, Yanshi Wang

Theses

The effects of weighting matrices that may be used in the Weighted Least Squares (WLS) method when applied to the problem of Power System State Estimation (PSSE) are studied. These weighting matrices include the one usually used in the literature and the one used in the utility PSSE programs

The performances of these weighting matrices are compared using the Monte Carlo simulation technique.

To test the performances of the weighting matrices, a PSSE program is developed, different performance indices for state comparison are defined, and many cases are studied.

Results show that the weighting matrix usually used in literature, 1/σ², …

Design Of A Real Time Optical Sensor For Continuous Blood Cell Separation, Girish S. Yerande

Theses

For continuous measurement and display of oxygen saturation and RBC content in blood during cell separation a reflection type optical sensor is designed based on the theoretical model using the photon diffusion theory. The prototype sensor consists of two arrays of light emitting diodes, red and infrared, and photodiodes. The emission wavelength of LEDs are 660 nm and 800 nm. The 800 rim which is in the infrared region is very close to isobestic value for blood. The prototype sensor is mounted on the blood cell separator equipped with an antitwister mechanism. Each LED emits a specific wavelength of light …

Trellis Coded Tamed Frequency Modulation In Rayleigh Fading Channels, Kiran R. Patel

Theses

It is usually difficult to reduce the effects of channel impairements on transmitted information. A fading channel is one such media in which digital communications system operates. A signal is subject to distortion in amplitude and phase when propagating towards the receiver. This puts constraint in required SNR at the receiver, for given performance. Various modulation/coding and demodulation/decoding techniques are employed to lessen the effects of fading. Bit error rate is a performance parameter that sets the criteria for signal design, system architecture and performance.

Here, a slow Rayleigh fading channel with three propagation paths possesing a scattering function of …

Lossless Image Data Compression Techniques Using High Order Markov Arithmetic Encoding, Santo Politi

Theses

It is difficult to compress digital images with acceptable ratios if a distortion is not acceptable. The lack of a rule based structure as in a language is one of the main reasons. In this work a number of algorithms for lossless image data compression are considered. The coding and the modeling aspects are treated separately. Different approaches are proposed to combine. Markov Arithmetic Encoding, a very efficient plain text encoding scheme, with source modeling algorithms to obtain higher compressibility. A modular approach is selected which enables combining various models. Model statistics are studied for further improvements. The schemes presented …

Single Token Integrated Dama In Multiple Bus Local Networks, Srinivasan Ramadurai

Theses

Multiple-bus local Networks (MBLNs) provide an architecturally simple solutions to serve high-reliability-high capacity local area networks(LAN) applications. Access mechanisms for MBLNs possessing stability and favorable delay characteristics are developed in this thesis. A new technique is proposed that uses a single explicit token to achieve demand assignment multiple access (DAMA) to arbitrate access on all the buses in the system. Analytical model was developed and compared to simulation results that indicates performance improvement in terms of delay characteristics of the system of buses.

Temperature Dependent Current-Voltage Characteristics Of Tisi2/N+/P Silicon Shallow Junctions, Bhupendra M. Shah

Theses

Analyses of temperature dependent current-voltage characteristics, of titanium silicide films on n+/p silicon shallow junctions, has been presented here. The fabrication technique involves the formation of shallow pn junctions, by ion-implantation of As+ through titanium films evaporated on P type silicon. The improvement of the activation of dopants has been fulfilled by different annealing processes in conjunction with the dopant drive-in. Electrical measurement of temperature dependent current-voltage technique has been employed to characterize these devices. The temperature dependent factors such as energy bandgap narrowing, majority carrier degeneracy, diffusivities, mobilities and minority carrier life time are evaluated by using key approximations.