Electrical and Electronics Commons^™

The Path Method In Power System State Estimation, Fareed A. R. Shirazi

Theses

A new method for Power System State Estimation (PSSE), the 'Path Method', is developed and studied. In this method the state (voltage magnitude and angle) of one node is calculated at a time, using only the local measurements. This procedure is repeated to calculate the state of all nodes in the system, following a predefined path to determine the next node whose state is to be calculated. In the process, more measurements are used whenever available and possible. Results obtained for this method are comparable and close to those of the Line-Flow Only (LFO) method. An advantage of the Path …

Computation Of Frequency Characteristics Of Lumped-Element 3 Db Branch Line Directional Couplers, H. R. Mgombelo

Tanzania Journal of Engineering and Technology (TJET)

An analysis of the 3 dB lumped-element branchline directional coupler constructed using L-C and T networks is given. Matrices of lumped element capacitances and inductances in the form of low and high pass filters are equated to the matrices of the distributed element transmission lines at the centre frequency of operation, as a result of which design equations are derived. Using even and odd modes of excitation, frequency characteristics of the directional couplers are computed and compared to those of the coupler constructed using distributed element transmission lines.

Charge Transfer Inefficiency Of Buried-Channel Charged Coupled Device Registers For Low Temperature Operation Of Ptsi Infrared Image Sensors, Benjamin Benjamin Esposito

Theses

Buried channel charge coupled devices used as readout registers in PtSi Schottky-barrier detector infrared image sensors were investigated to characterize factors that influence charge transfer efficiency at low temperatures ranging from 38 to 80K. These factors included frequency of operation, background signal, gate voltage, signal level, gate length, and temperature. It was found that increased gate voltage and decreased gate length are most effective in reducing charge transfer efficiency. This was attributed to increased fringing fields between the potential wells involved in charge transfer. As temperature was decreased from 50K to 38K progressively larger trapping losses were observed due to …

Netexpert, An Expert System For Computer Network Management, Sailen Patel

Theses

Data Communications systems consist of distributed software and hardware components executing concurrently a number of communications functions. The logical framework for these functions is called data communication architecture and is layered hierarchically according to the OSI model. The protocol defines the syntax and semantics of the communications between entities of the same layer. NETEXPERT: An Expert system described here contains a set of formal specifications corresponding to different abstractions level of the protocol. On the highest level there is a specification of the service provided by this protocol. On the consecutive lower levels there are successive refinements of this specification …

Microcomputer Control Of An Ac Induction Motor Using A Pwm Computational Intensive Method, Luther William Schnug

Theses

A three-phase microcomputer based AC Inverter has been developed using a computational intensive PWM algorithm that generates the output bridge switching patterns in real time. This approach utilizes the on-board capabilities of an advanced microcontroller, (a 16-bit 8097 from Intel), to eliminate most of the external hardware, and demands on memory size, required in other designs. This algorithm implements in software the Triangular Modulation Method of PWM generation, and utilizes a trapezoidal approximation to the sinusoidal reference waveform. Brassboard tests have shown that this approximation produces 5th and 7th harmonics that degraded performance, at low speeds. An enhanced algorithm, utilizing …

Lf Pulse Magnetic Field Generation And Uniformity Studies, Shun-Wen Tan

Theses

This thesis dealt with the design and construction of a pulsed magnetic field (PMF) generation circuit. The spatial variations of the generated PMF are also studied The generated PMF is intended to be used for two purposes (a) in hospitals, for its healing effect of broken bones, and (b) to study the effects of PMF on industrial bacteria and their activity in transforming toxic waste to benign waste

A square coil made of two sections is constructed and the associated circuitry for the PMF generation is designed and built The circuitry is divided into two parts. the control circuit and …

An Application Of Bit Level Systolic Arrays On Digitized Adaptive Array Processes, Shin-Hwa Tsai

Theses

This thesis has concentrated on some aspects of adaptive arrays, i.e., the data type as well as the calculating processes under an optimized version. An adaption of a modified bit-level array is described on the control structure for processes like correlation matrix, Q-R decomposition and solution of triangular linear systems. In short, an implementation of SMI(Sample Matrix Inversion) under a parallel systolic array process is consider5ed. Also an application of utilizing systolic array on a matrix inversion is derived. As a result, it could be predicted that a VLSI chip implementation for small adaptive arrays is feasible in the near …

Reflectance Of An Absorbing Substrate For Incident Light Of Arbitrary Polarization: Appearance Of A Secondary Maximum At Oblique Incidence, R. M.A. Azzam, A. M. El-Saba

Electrical Engineering Faculty Publications

The reflectance of an absorbing substrate Rθ(ɸ) is considered as a function of the angle of incidence ϕ and an incident polarization parameter θ, where cos²θ and sin²θ give the power fractions of incident radiation that are p-and s-polarized, respectively. Taking GaAs as an example, we find that at certain wavelengths (e.g., 0.248 and 0.620 µm), the R_θ vs ɸ curve becomes oscillatory in a narrow range of θ > 45° with an unexpected secondary maximum appearing at oblique incidence. The extrema of the function R_θ(ɸ) are determined numerically, and their angular …

Learning System, Bhavesh T. Adani

Theses

Many rule-based learning systems have been implemented which generate and update rules/facts from illustrative examples provided by the user. But very few of them have succeeded in achieving the efficiency and accuracy of an ideal system.

The approach made here is to continuously update the hierarchical structure of rules/facts of a knowledge-base so that efficient and accurate solutions to any query can be achieved easily and immediately from the many possible solutions to the query. As the rule-based systems deal with a very large knowledge-base, it is sometimes necessary to apply a learning technique that finds optimum solutions efficiently.

The …

Waveform Analysis And Application To A Model Of The Egg Waveform, Eu-Rune Chang

Theses

The purpose of thesis is to describe and investigate a model of electroglottogram waveform. At the beginning, we generate a set of sine waveform models to analyze by using Fourier transform theory. Then, according to the electroglottogram is conjectured to be related to the area contact between the vocal folds, we assume a simple model of vocal fold vibratory motion is used to estimate the vocal fold contact area as function of time. Therefore, we modified and developed the mathematic EGG waveform model by using personal computer program computation to become a set of realistic EGG waveform models, which are …

Analysis And Design Of A Surface Microengineered Silicon Humidity Sensor, Uei-Yanq Chen

Theses

This thesis details the design for a solid-state humidity sensor which utilizes state-of-the-art silicon technology. The sensor design utilizes a microengineered surface which includes a polysilicon airbridge structure as heater and sensor element in an integrated device.The operation of this device depends upon the small variation of thermal convection coefficient which effects the temperature of the heated element within the device. The temperature of the polysilicon bridge is monitored by means of a resistance bridge. In one design(sensor I) a single polysilicon airbridge is used for both the heater and resistance sensing element. Also a second inferior design (sensor II) …

Optimal Cache Size In Microprocessor-Based Multiprogramming System, Charalambos Stephanou Christou

Theses

The Motorola 68020 microprocessor, its paged memory management unit MC68851 and cache memories are rigorously studied. The simulation model of this uniprocessor, multiprogramming system was constructed and tested to determine the optimal physical cache size.

The parameters varied in the model are the cache size, the degree of multitasking, the loop count and size, the cache algorithm and the time slice given to every task. A number of simulations have been conducted and the results are examined.

Arithmetic Pipline Scheduler, Chun-Ta Pan

Theses

A schedule is used to determine which stages of an arithmetic pipeline are active at any particular time. It can determine when another process can be introduced into the pipeline so no more than one set of data will use the same stage at the same time. The Arithmetic Pipeline Scheduler (APS) is a software tool used to analyze schedules for different operations and determine greedy schemes for introducing data into the pipeline. The user can use APS to process up to ten arithmetic equations. The user also can use APS to define different configurations of stages. Besides, APS can …

Kalman Filtering Applied To The Analysis Of Brainstem Auditory Evoked Potentials, Chong An Qian

Theses

The objective of this thesis is to detect the Brainstem Auditory Evoked Response (BAER) using lower numbers of averages than at present, by using an optimal smoothing method which is based on the Kalman Filter.

By using this method, the wave V latency of the BAER which is useful in testing for hearing loss can be detected with as low as 500 averages, while the traditional signal averaging method requires at least 2000 averages. Thus the time required for a hearing loss test can be reduced from one hour to approximately 20 minutes.

Also several other methods for detecting BAER …

Computer Analysis Of The Electrocardiogram Using Hardware Digital Signal Processing, Mohammad Ashfaque Shaikh

Theses

A system based on the microcomputer IBM PC-AT has been realized to acquire and filter the clinical electrocardiogram (ECG) data in real time. The system program further detects and analyzes the ECG signals for possible cardiac arrhythmias.

This research is based on work done by previous researchers and achieves significant goals towards achieving on-line arrhythmia detection using a microcomputer. The system uses the hardware and software package ASPI 320/PC from Atlanta Signal Processors Inc. This hardware configuration uses a special purpose instrumentation microprocessor ( TMS32010 from Texas Instruments) to coprocess the ECG signals. Coprocessing the signals with the ASPI 320/PC …

Division-Of-Wave-Front Thin-Film Beam Splitter For Generating Binary Patterns Of Orthogonal Elliptical Polarization States, R. M.A. Azzam

Electrical Engineering Faculty Publications

A division-of-wave-front thin-film beam splitter is described that reflects monochromatic light at oblique incidence with orthogonal elliptical polarization states. It consists of a metallic substrate partially covered with a transparent thin film that inverts the ratio ρ of the complex p and s reflection coefficients at the principal angle of the metal. Any pattern of coated and uncoated areas of the substrate is imprinted upon the reflected wave front as a corresponding two-dimensional spatial binary polarization pattern. A specific design is given that uses a Au substrate at a wavelength of 632.8 nm. The effects of small errors in the …

Thin-Film Devices For Polarized Light- Introduction, R. M.A. Azzam, William H. Southwell

Electrical Engineering Faculty Publications

No abstract provided.

Data Extraction And Analysis In Glucose Monitor, Chang Qian

Theses

For the purpose of building a workstation to read and analyze data from hand-held, home use glucose monitor, a new high performance Digital Oscilloscope Peripheral (DOP) for PC is used to easy sample and store data, and it is described here. The new features of DOP are discussed and some application software packages for different purpose are described here in detail.

Since the sampled data from the hand-held, home use glucose monitor is irregular and in random form, the Least-Square Polynomial Modeling Method is used to produce a fit curve line, which best goes through most data points. Using the …

Clinical Base Station For Portable Patient Monitoring Equipment, Silin Kuang

Theses

In today's clinical environment, where it is not always desirable to have a computer terminal present, a microcontroller-based biomedical system with multi-purpose features is needed. The present work offers an approach for a clinical based desktop workstation that provides the physician with record files, general management of his patient group, and specific algorithms for patient or group analyses. The workstation has the capabilities to acquire a large number of data from a portable patient monitoring device, generate a hard copy graphic record, create a patient cardfile and an . office personnel loggin file, and check patient's appointment and emergency list. …

Istemcr : Integrated System For Truck Engine Monitoring Via Cellular Radio, Tse-Shan Pan

Theses

The study presented is aimed at the application of the Data Acquisition to The Truck Engine as the source of all the signals, with the mobile telephone Cellular Radio system.

A Word Based Data Compression Using Arithmetic Encoding, Christopher Dean Peckham

Theses

It is usually difficult to compress data from a statistically unknown source and yield a good compression ratio. Using the fact that words are the fundamental basis of the written language, a data compression scheme based on words should yield high compression ratios. Discussed here is a compression scheme that gathers words from the source stream and places them in a dictionary, or word list, to use later in the coding, thereby becoming adaptive to the words in a given file without prior knowledge of the source. When a word is in the word dictionary, it is encoded by its …

Implementation Of A Cross Coupled Phase Locked Loop System With Closed Loop Amplitude Control, Behzad Sadeghi

Theses

A system was designed, to demodulate an FM signal in presence of an interfering signal whose frequency was very close to the desired signal, this system was implemented and tested based on the theory of cross coupled phase locked loop systems, originaly proposed by (1).

This system included two phase locked loops for the purpose of demodulation, two low pass filters and two integrators, for the purpose of amplitude estimation. Two additional phase locked loops were designed to act as a 90° phase shifter. The following is the result of the theory, design procedure and some tabulated data for this …

Extrema Of The Magnitude And The Phase Of A Complex Function Of A Real Variable: Application To Attenuated Internal Reflection, R. M.A. Azzam

Electrical Engineering Faculty Publications

Given a complex function F(ω) = |F(ω)|exp[jΔ(ω)] of a real argument ω, the extrema of its magnitude |F(ω)| and its phase Δ(ω), as functions of ω, are determined simultaneously by finding the roots of one common equation, Im[G(ω)] = 0, where G= (F′/F)² and F′ = ∂F/∂ω. The extrema of |F| and Δ are associated with Re G < 0 and Re G > 0, respectively. This easy-to-prove theorem has a wide range of applications in physical optics. We consider attenuated internal reflection (AIR) as …

Assessment Of Autonomic Regulation Of Heart Rate Variability, Shaw-Jyh Shin

Dissertations

Complex demodulation, accompanied by the techniques of interpolation, detrending and zero-phase-shift lowpass filtering were used to examine the effect of both divisions of the autonomic nervous system (sympathetic and parasympathetic) on heart rate by analyzing the heart rate variability signal from dogs under two different classical conditionings: CS+ and CS-, which cause different dynamic pattern changes in the autonomic nervous system to regulate the heart rate.

Unlike power spectral analysis, complex demodulation gives results in the time domain and shows the variation of amplitude and phase over time at a given frequency. The variation of phase indicates the frequency deviation …

Effects Of Peripheral And Microwave-Core Heating On Survival In Hemorrhagic Shock In Rats, Ashraf Sabry El-Assuooty

Theses

In a model of rats resuscitated from hemorrhagic shock,where 11 of 12 animals were alive up to 4 hours after shock, there was an average drop of 10°C in core body temperature. Survival and morbidity was much impaired when the shocked animals were externally heated with an infrared lamp to maintain a core body temperature of 35°C. Since the increased intrashock mortality is possibly due to the circulatory changes induced by peripheral heating, an attempt was made to determine the effects of heating the animal at its core. Twelve rats were shocked in the same fashion, however the body core …

A Computer-Based Microwave Interferometer Instrumentation System As A Non-Invasive Cardiopulmonary Monitor, Chin-Yee Eric Ho

Theses

The system comprises a microwave interferometer as a computer-based non-invasive cardiopulmonary monitor. The microwave interferometer records the mechanical vibration of the chest wall. The objective is to determine whether the signals may have diagnostic value and to evaluate the instrument as a non-invasive and non-contacting cardiopulmonary monitor.

With the help of a computer it is possible to analyze the mechanical vibration of the chest wall produced by the heart and thereby detect, and possibly categorize, cardiac abnormalities. This system is able to process two channels, the first signal from microwave interferometer records chest wall vibrations and the second signal is …

Independent Equations Method For Power System State-Estimation, Shun-Gee Lin

Theses

The problem of power system state estimation (PSSE) is to convert the available. redundant and noise contaminated measurements, and other information into a best estimate of the state of the system.

Methods to solve the PSSE, including the sub-problems of bad data presence detection, identification and reconstruction, are reviewed. The Independent Equations Method (IEM) was selected for in-depth study and analysis.

The tree method for bad data identification is tested and failed due to the suspected ill-conditioning of the sensitivity matrix. For bad-data reconstruction, the IEM fails as described. Modifications that saves computing time and ensures reconstruction success are presented …

Reliability Problems In Semiconductor Lasers, Ajay R. Patel

Theses

The stability and reliability of semiconductor laser is dependent on its design, fabrication, and output power. The best way to assure high reliability of these devices is by accelerated aging test and by selection of strict and meaningful criteria for the acceptance or rejection of a particular device. In this thesis emphasis is given on different failure mechanisms that are known. As new development takes place, other mechanisms may be found. Catastrophic degradation, gradual degradation, darkline defects, and contamination during the fabrication process are the main source of device failure.

The noise generation and the packaging issue of semiconductor laser …

Temperature Dependent Reliability Of Plastic Packaged Microcircuits, Wasim Ahmed

Theses

Increasing power and power densities in new high complexity semiconductor devices are creating heat removal problems. Increased powers produce higher junction temperature which lead to potentially faster degradation of device reliability. Thermal management at device level packaging involves efficient and cost-effective removal of dissipated thermal energy from the device to assure its reliable performance over the long term. In the context of very high levels of integeration of future ICs, thermal management will mean making such devices possible close to the limits of acceptable high temperature.

The major factors affecting heat flow in a plastic Dual-in-line-packages (DIP'S) are investigated using …

Development Of 8052ah-Basic Based Single Board Computer Ii, Suping Lou

Theses

8052AH-BAISC Based Single Board Computer II ( SBC II ) is designed and developed for the application in biomedical instruments as an embedded central processing unit. SBC II offers powerful function in digital signal acquisition, storage and processing, smart on-board EPROM programming, various preipheries supporting and custom supervisor program. The techniques of design and development of SBC II includes computer aided circuits analysis and schematic, optimal design algorithms and computerized setting up SBC II prototype.

This thesis combines the analysis of SBC II circuitry, set up and operation of the complete computer aided electrical circuit design software OrCAD/SDT specifics in …