Engineering Commons^™

Properties And Device Applications Of Hydrogenated Amorphous Silicon Carbide Films, M. Mahmudur Rahman, Cary Y. Yang, D. S. Sugiharto, A. S. Byrne, M. Ju, K. Tran, K. H. Lui

Electrical and Computer Engineering

Hydrogenated amorphous silicon carbide (a‐SiC:H) films were deposited with a radio‐frequency plasma‐enhanced chemical vapor deposition system which utilizes a dc electric field applied independently of the inductively coupled rf field. The source gases were SiH₄ and CH₄. It was found that application of an electric field directed out of the substrate surface enhances the growth rate and yields some improvements in photoconductivity. The compositions of the films were evaluated by x‐ray photoelectron spectroscopy for a range of source gas mixtures. In order to assess the applicability of a‐SiC:H thin films, heterojunction a‐SiC:H/crystalline Si (c‐Si) diodes were fabricated …

Coke Oven Emissions: A Case Study Of Technology-Based Regulation, John D. Graham, David R. Holtgrave

RISK: Health, Safety & Environment (1990-2002)

After examining and analyzing the experience with coke ovens, the authors conclude that attempts to force technology beyond its demonstrated competence can be both expensive and ineffective in controlling hazards. They also suggest implications for pending proposals to further control air pollution.

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 …

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; …

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 …

Non-Parametric Dominant Point Detection Algorithms, Kuo-Wei Huang

Theses

Dominant point detection is one of the most important preprocessing steps for landmark-based shape recognition and point-based motion estimation. Two new methods for detecting dominant points are presented. Both methods do not require any input parameter and the dominant points obtained by these methods remain relatively the same even when the object curve is scaled or rotated.

In the first method, for each boundary point, a support region is assigned to the point based on its local properties. Each point is then smoothed by a Gaussian filter with a width proportional to its determined support region. A significance measure for …

An Mcs Basic-52 Sbc Using Anything But An 8052ah-Basic, Hyunyeop Lee

Theses

This thesis exploits the ways to develop a new MCS BASIC-52 SBC using anything but an 8052AH-BASIC microcontroller. The 8052AH-BASIC based SBC offers short development time and low system cost; it is advantageous for numerous applications especially in the instrumentation, measurement and process control. However, the 8052AH-BASIC is no longer officially supported by INTEL and could disappear. Also, this SBC is not adequate for applications where power consumption is an important factor because the 8052AH-BASIC, a MOS product, draws a considerable amount of current.

To solve these problems we demonstrate how the 8052AH-BASIC can be replaced by any of a …

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.

Application Specific Integrated Circuits For Single Board Computer, Ximing Shi

Theses

A single board computer is the central part of many microprocessor-based instruments. The implementation of the logic portion of a single board computer using Xilinx Logic Cell Array makes the computer system more powerful. Xilinx Logic Cell Array is a new kind of Programmable Gate Array in application specific integrated circuit with high design flexibility and functional density. The XACT Development System provides schematic capture and auto place-and-route for design entry.

In this thesis, a Xilinx Logic Cell Array was developed and implemented in the 8052AH-Basic based Single Board Computer design. Also, the logic and timing verification and simulation of …

Delay Improvement And Reliability Enhancement In A Cim-Based Factory Network, Vimalkumar Upadhya

Theses

Today, Computer-Integrated Manufacturing (CIM) refers to the integration of computer-controlled factory floor devices with engineering design and plant management computers. In general, there is a need for more efficient factory networks than are currently available. To this end, it is essential to investigate new network architectures and study their performance.

A number of CIM networks are analyzed in this thesis, and a new CIM network architecture is proposed. The throughput and delay characteristics of all these network architectures are derived from their respective simulation models. The results indicate that the proposed CIM network architecture has superior performance characteristics, compared to …

Optical Isolation Of Single Board Computer For Use In High Electrical Noise Environments, Meng Xiao

Theses

This thesis describes various electrical noises, noise environments and noise effects for electronic logic circuitry. The optical isolator is introduced and its concept, classification and characteristics are discussed.

Various design considerations are reviewed: input forward current, reverse breakdown protection, threshold, current transfer ratio, isolation voltage, data rate, common mode rejection, CMOS compatibility, isolation resistance, isolation capacitance, temperature effect and cost.

A multi-channel optical isolated input/output interface board for 8052AH BASIC SBC is designed. It includes 16 input channels, 16 output channels, decoder circuit, latching circuit, PC895 interface and input protection circuit. The sample board has been built, tested in the …

Design And Processing Of Micromechanical Sensor Devices, Zhixiong Joe Zhou

Theses

A multi-purpose cantilever beam and microbridge accelerometer structure has been designed and fabricated in this work. This same structure with modification can be employed as a capacitive accelerometer, mechanical resonance accelerometer, and a piezoresist accelerometer. Surface microengineering processing techniques have been developed in this work. The cavity structure significantly reduced the parasitic capacitance. This work reports the first instance of spin-on glass for rnicromechanical device applications as both a sacrifical layer and a planarization material for the cavity. Other results of this thesis including:

1. LPCVD low temperature oxide as the base material from which the cavity is etched;

2. …

A Stereo Vision Technique Based On The Multi-Positioned Camera Criterion, Jie Bao

Theses

A modified feature based stereo vision [sic] technique is described in this thesis. The technique uses the curve-segments as the feature primitives in the matching process. The local characteristics of the curve-segments are extracted by the, Generalized Hough Transform.

A set of images of a scene, which are taken by a multi-positioned camera satisfying the parallelism criterion, are first filtered by the Laplacian of a Gaussian operator in different widths, i.e. coarse to fine channels. At each channel, the Generalized Hough Transform is applied to the curve-segments in each image. The curve position, the curve-length, the curve centroid, the average …

Token Bus Lan Performance : Modeling And Simulation, Ramesh Kurnool

Theses

A simulation model based on CSIM, a process oriented simulated language, to analyze the performance of the Token Bus protocol is developed. Performance measures such as throughput, average delay and maximum delay per packet are presented. System performance is analyzed for different loads, number of stations, network lengths, different physical and logical distribution of the stations with packet length as a parameter. Previous studies were based on the delay-throughput analysis with no discussion on the effect of variation of the logical and physical distribution of the stations on the performance of the model which is done in the present thesis. …

Performance Evaluation And Comparison Of Ordinary, Adaptive And Exhaustive Service In The Token Ring Network, Darshakkumar J. Patel

Theses

In the token ring network different types of services gives different delay characteristics. Results to date have shown that in asymmetric traffic, exhaustive service gives more delay to lightly loaded stations where ordinary service wastes time in circulating the token after each transmission. In general, there is a need for more efficient service, which is compromised between ordinary and exhaustive service.

Ordinary and exhaustive service are analyzed in this thesis, and a new service, adaptive service, is proposed. By using timer and counter, adaptive service dynamically changes token holding time at the station. Different types of delay characteristics are derived …

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 …

Eeg Mapping Using The Personal Computer, Zhuan-Zhang Pei

Theses

An approach for brain electrical activity mapping using a personal computer has been investigated to enhance the visibility of the EECs. An automatic procedure from data acquisition to the final mapping has been developed for on-line or off-line data processing, in which a table-look-up technique has been introduced to eliminate redundant processing. The power spectra in different EEC frequency bands for four electrodes are coded into 15 colors and mapped on a color monitor. The data correspondings to the areas between electrodes are interpolated by the surface spline method. The mapping speed and smoothness has been optimized. An experiment has …

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 …

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. …

A Code Verification System For Ink Jet Printing, Daniel Liang Hsu

Theses

This paper describes system integration of a code verification system. The system utilizes a feature matching

Cryogenic Characterization Of Potential High Temperature Superconducter Substrates At Microwave Frequencies, Sukhmani Kaur

Theses

The lack of characterization data for dielectric substrate materials at microwave frequencies and cryogenic temperatures hinders the development of high T_c superconducting circuits. Low loss (tanδ < 10^-4) substrates with dielectric constants in the range of 5-100 at cryogenic temperatures are needed to realize the advantages of superconductor circuits. Measurement techniques previously reported are either time consuming or inaccurate. We report an adaptation of Courtney's method for accurate, simple evaluation of complex dielectric constants (10 < ε_r < 100) at low temperatures. The fixture was calibrated using known properties of polycrystalline ZrSnTiO4. We measured er and tans on three potential substrate materials, Al₂O₃, MgO, and LaAlO₃ at 5-10 GHz in the temperature range 77-300K. No temperature hysteresis in either ε_{r …}

Optimum Power System Planning, Youn Tae Kyong

Theses

This thesis presents analysis method of optimum power system planning. The Gauss-Seidel iteration method is used to calculate load flow data of power system. The real and reactive powers, voltage magnitude and phase angle at each bus were obtained using Gauss-Seidel iteration method for a given IEEE sample power system. The load flow calculations were repeated under 60 percentage, 70 percentage, 80 percentage, 90 percentage, 100 percentage loading condition.

The transformation of reference frames were performed to simplify given IEEE sample power system identification. The transformation of reference frame transforms real and reactive voltage, current and impedance variables(reference frame 1) …

Automatic Contour Extraction From Hvem Image Of Microvessel, Yong-Gang Liu

Theses

The research work reported in the thesis is motivated by the problem raised in the biomedical research utilizing high voltage electron microscope (HVEM) to study microvessels. There the contour data of cross-sections of microvessels are fed into some special electronic device to reconstruct three-dimensional pictures of microvessels. However, the contour data acquisition as routinely conducted by manual operation. This tedious procedure costs large amount of human power.

In this thesis, computer image processing techniques are applied to replace the time-consuming manual operation. A synthetic method is recommended. A software with various digital image processing functions has been developed and tested …