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Electrical and Electronics Commons

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1990

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Articles 121 - 150 of 155

Full-Text Articles in Electrical and Electronics

Single Token Integrated Dama In Multiple Bus Local Networks, Srinivasan Ramadurai May 1990

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.


Application Specific Integrated Circuits For Single Board Computer, Ximing Shi May 1990

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 …


Design And Analysis Of Microengineered Accelerometer, Nana Shigematsu May 1990

Design And Analysis Of Microengineered Accelerometer, Nana Shigematsu

Theses

This master's thesis is about microengineered accelerometer integrated on a silicon wafer using two polysilicon layers acting as capacitors. This accelerometer operates as a capacitor sensor which is built between two polysilicon layers. It senses a difference of acceleration of gravity, or weight of the polysilicon beam. Both changes tend to change the capacitance between two layers, therefore, to change the resonant frequency of a resonant circuit built using this device and external inductors.

This master's thesis involves theoretical calculations of capacitor sensor for three sizes of capacitor area. Even though this sensor has not been fabricated yet, this sensor …


A Stereo Vision Technique Based On The Multi-Positioned Camera Criterion, Jie Bao May 1990

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 May 1990

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 May 1990

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 …


An Artificial Neural Network For Redundant Robot Inverse Kinematics Computation, Wibawa Utama May 1990

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 May 1990

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 …


Eeg Mapping Using The Personal Computer, Zhuan-Zhang Pei May 1990

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 May 1990

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 May 1990

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 …


Performance Studies Of Lapped Orthogonal Transforms, Frank E. Wadas May 1990

Performance Studies Of Lapped Orthogonal Transforms, Frank E. Wadas

Theses

The comparative performance of several Lapped Orthogonal Transforms(LOTs) [1][2][3][12] is studied in this thesis . Blocking effects of conventional block transforms at low bit rates are reduced with LOT, through basis functions that overlap in adjacent blocks. The block transforms of Discrete Cosine Transform (DCT), Discrete Sine Transform (DST)[4], Discrete Legendre Transform (DLT), and the Modified Hermite Transform (MHT)[16] are extended to LOT in a way that a fast algorithm for nearly optimal LOTs is derived. The Markov and two different exponential correlation models are used as the source models for the derivation of these LOTs. It is shown that …


An Adaptive Robotic Controller With High Robustness, Xiao-Tian Wen May 1990

An Adaptive Robotic Controller With High Robustness, Xiao-Tian Wen

Theses

A complex industrial application of robotic manipulators are beyond the capability of the relatively simple constant gain linear control system. They compensate poorly for nonlinear dynamic model and environment changes, especially when the plant model comes with the unknown coefficients. An adaptive controller for a two joints robotic arm is designed in this thesis. Firstly, the highly coupled nonlinear model is linearized, and then an adaptive regulator is employed which adjust the controller parameters directly based on the on-line parameter estimation, where a least square identification is used. At last the computer simulation is also performed.


Optical Isolation Of Single Board Computer For Use In High Electrical Noise Environments, Meng Xiao May 1990

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 …


Temperature Dependent Current-Voltage Characteristics In Thin Sio2 Films, Jin Zhao May 1990

Temperature Dependent Current-Voltage Characteristics In Thin Sio2 Films, Jin Zhao

Theses

An analysis of the Fowler-Nordheim tunneling (FNT) theory and its application to temperature dependent current-voltage characteristics, of very thin films of SiO2 on silicon, is presented. The final results are believed to provide the most complete examination of FN emission theory and predict the breakdown electric field in thin SiO2 films. The role of the roughness, at the Si-SiO2 interface, in determining the FNT current and breakdown mechanisms in metal-oxide-semiconductor (MOS) structures are also discussed.


Automatic Infrared Inspection Of Solder Joints On Mounted Circuit Boards, Ken Kekuan Zhou May 1990

Automatic Infrared Inspection Of Solder Joints On Mounted Circuit Boards, Ken Kekuan Zhou

Theses

This thesis reports the research work on automatic infrared and visual light inspections of solder joints on printed circuit boards (PCBs) utilizing an image processing system and statistical pattern recognition techniques.

A small scale image processing system, consisting of a SUN workstation and several DATACUBE modules, is set up for the research. Software packages for imaging, displaying and solder joint inspection are developed and ready for public usage.

The capability of infrared inspection for solder joints on PCBs is demonstrated. The fusing of infrared and visual light imagery for the inspection is shown to offer better results than that obtainable …


A Code Verification System For Ink Jet Printing, Daniel Liang Hsu May 1990

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


Image Data Compression With Neural Networks, Jianjun Li May 1990

Image Data Compression With Neural Networks, Jianjun Li

Theses

Three efficient image coding schemes, based orb neural networks, have been developed in this thesis: (1) Neural network vector quantization (NNVQ). The main advantage of this new technology is that it can accomplish the complex encoding process much faster than the previous algorithms. Its properties are studied and demonstrated by simulations. (2) A adaptive NNVQ for image sequence coding. Simulation experiments have been carried out with 4 x 4 blocks of pixels from an image sequence consisting of 40 frames. At 0.67 bits/pixel, this scheme achieves good image quality suitable for videoconferencing systems; (3) Neural network prediction. This new prediction …


Trellis Coded Tamed Frequency Modulation In Rayleigh Fading Channels, Kiran R. Patel May 1990

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 …


Control Of Stress In Silicon Nitride Thin Films, Ajay Krishnan May 1990

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 May 1990

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 …


Analysis And Development Of A Switched Capacitor Power Supply, John Richard Hackworth Apr 1990

Analysis And Development Of A Switched Capacitor Power Supply, John Richard Hackworth

Electrical & Computer Engineering Theses & Dissertations

The combination of a switched capacitor network and switching power supply techniques can result in a transformer less regulated DC power supply that is small, relatively simple, and efficient. In addition, the output of such a system could be operated over a wide range of common mode voltages. Multiple switched capacitor supplies could be stacked to achieve voltage multiplication.

Although the output of a system of this type is a continuous function, the internal operation must be analyzed in finite time elements. This numerical analysis will be shown in both a mathematical approach and a computer model.


Adaptive Fir Digital Filter Design And Simulation In The Noise Reduction System, Jack Jiabing Pang Jan 1990

Adaptive Fir Digital Filter Design And Simulation In The Noise Reduction System, Jack Jiabing Pang

Theses

The adaptive FIR digital filter is designed to suppress the noise in the tape recording and audio communication systems. The cutoff frequency of the digital FIR filters can be varied adaptively depending on the energy level of the input signal. In audio communication, especially, in tape recording systems, the noise obviously gets much bigger, when the frequency band of the system increases. The noise reduction system makes use of a phenomenon called masking, where the big signal-to-noise ratio makes human ears not sensitive to the noise. In a constant interval time, the system detects the signal level and compares the …


Uniformity Corrector And Signal Processing For A 160 X 244-Element Ir-Ccd Camera With Ptsi Schottky-Barrier Detectors, Paul D. Blume Jan 1990

Uniformity Corrector And Signal Processing For A 160 X 244-Element Ir-Ccd Camera With Ptsi Schottky-Barrier Detectors, Paul D. Blume

Theses

An off-set-type, one point response uniformity corrector and the associated signal processing circuits was developed to be used for a 160 x 244-element IR-CCD camera with PtSi Schottky-barrier detectors. Image sensors with PtSi Schottky-barrier detectors exhibit two types of noise in the displayed video output, a temporal noise and a spatial fixed pattern noise. The performance of the image sensor, limited by the spatial noise which obscures low contrast detail and limits camera sensitivity, can be improved by a uniformity corrector. The uniformity corrector was constructed to substantially reduce the spatial noise in the output display by digitally subtracting a …


Infrared Tv Camera With Ptsi Schottky-Barrier Detectors, Steven J. Blume Jan 1990

Infrared Tv Camera With Ptsi Schottky-Barrier Detectors, Steven J. Blume

Theses

An infrared TV camera was developed for operating various sizes of Schottky-barrier IR-CCD image sensor chips. A digitally programmable frequency synthesizer is used so that the camera has the flexibility of using a 160 x 244 or 320 x 244 image sensor developed at the David Sarnoff Research Center. The outputs of the camera are compatible with an XYZ monitor, a standard TV monitor, and a computer workstation. Operation of the camera was demonstrated with a 160 x 244 image sensor producing an output on a standard TV monitor. Performance of the IR-TV camera system was investigated by evaluating CCD …


Performance Analysis Of A Dynamic Reservation Multichannel Local Area Network, Abubakar A. Ibrahim Jan 1990

Performance Analysis Of A Dynamic Reservation Multichannel Local Area Network, Abubakar A. Ibrahim

Theses

A reservation multiaccess protocol. is proposed to be used on multichannel local area networks. This protocol is advantageous for networks supporting integrated services. The delay and throughput performance for message transmission are obtained by analysist The delay performance of the protocol is similar to the M-CSMA/CD/IC multichannel network proposed by Marsan and Roffinella. It is found that the reservation protocol can provide better throughput-delay characteristics when the fraction of the total available bandwidth allocated to data is increased. It is also observed that the maximum throughput increases with the increase in the number of channels when the total bandwidth is …


Formation And Characterization Of Thin Superconducting Y-Ba-Cu-O Films, Gyusuk Kim Jan 1990

Formation And Characterization Of Thin Superconducting Y-Ba-Cu-O Films, Gyusuk Kim

Theses

Thin Y-Ba-Cu-O superconducting films were fabricated reproducibly on MgO (100) substrates by two different processes ; (1) deposition at a low substrate temperature fiom a single sintered YBa2Cu3.3Ox target using RF diode reactive sputtering followed by a post-annealing at around 830 ° C ; (2) deposition at the crystallization temperature under oxidizing atmosphere. The superconducting properties of films deposited by process (1) and (2) were studied. The variation of film composition and thickness as a function of distance from the target gas pressure and distance between target and substrate was studied. The Dependence of the …


The Magnetotransport Analysis Of Hemt Structures At Low Fields, Naghmeh Nouri Jan 1990

The Magnetotransport Analysis Of Hemt Structures At Low Fields, Naghmeh Nouri

Theses

On the basis of a study on numerous HEMT structures, a simple and useful technique was established for the characterization of 2DEG layers. This technique utilizes the magnetic field-dependence of the resistivity and Hall coefficient of the HEMT structure, to determine the values of the sheet density and mobility of 2DEG in the presence of other parallel conductive layers. This method of analysis was compared with previously used techniques such as Shubnikov-de Haas and the etch removal of the parallel conductive layers. Through this comparison and several measurements it was found that this procedure gives reproducible values for the 2DEG …


Sputter Deposition And Characterization Of High Tc Superconducting Thin Films, Vipulkumar Patel Jan 1990

Sputter Deposition And Characterization Of High Tc Superconducting Thin Films, Vipulkumar Patel

Theses

Preparation of thin superconducting films by direct RF sputter deposition on Si, MgO, SrTiO3 and quartz substrates and silver and Sl3N4 buffer layers (deposited on silicon substrates) was studied. To study resistance versus temperature characteristics of thin films and bulk materials, a computerized measurement system was developed. 1-1.5 pm thick YBaCuO films deposited on Si3N4/Si were found to be insulating with room temperature resistance higher than 236KΩ, while films with Ag as a buffer and/or a passivating layer exhibited metallic behavior with room temperature resistances lower than 700mΩ. The area directly under the 2.25 inches …


The Design Of Decentralized Optimal Regulator Systems Using Matrix Minimum Principle, Sunny Lai Yick Jan 1990

The Design Of Decentralized Optimal Regulator Systems Using Matrix Minimum Principle, Sunny Lai Yick

Theses

This research considers the design of linear, time-varying regulator systems using Matrix Minimum Principle in the frame work of decentralized control theory. The regulator system is modeled in terms of state equation with multiple controllers. Each controller works cooperatively to optimize a common quadratic performance index. An additional constraint is imposed such that the controllers are linear time-varying functions of the outputs.

Necessary and sufficient conditions for optimality of the system are provided by the Matrix Minimum Principle and Hamilton-Jacobi Theory.

Two examples are developed to illustrate the concept.