Digital Commons Network^™

A Wideband Continuous Phase Shifter For Ka-Band, William J. Tanis

Theses

The design, fabrication and test of a 45 degree microstrip phase shifter capable of full Ka-band performance is presented. The design uses a Lange coupler with two ports terminated with beam-lead varactor diodes to provide continuous phase shift. Although this concept has been employed at X-band and below, this thesis demonstrates its feasibility for wideband use at frequencies as high as 40 GHz. The design uses thin-film capacitors, beam-lead diodes, simulated grounds, and air bridges to achieve a planar geometry and to simplify the production process. Detailed test results using various test circuits are shown for comparison to actual phase …

Use Of The Lms Algorithm In Ecg Analysis, Xiaohua Yang

Theses

The purpose of this thesis is to develop an IBM PC-AT based system to effectively process electrocardiogram (ECG) signals. Adaptive filter theory is used to implement a noise cancellation system (adaptive noise canceller), which adaptively cancels the ECG signals resulting in real ECG noise. The adaptive process is based on the well known least-mean square (LMS) algorithm.

The noise canceling system is software based. Several programs have been written, which include analog to digital converter control, data acquisition and storage, data retrieval, adaptive filtering and digitized data graphics.

The thesis presents numerous computer experiments. The performance of the adaptive noise …

Progressive Transmission Of Images Using Pyramidal Structure, Chin-Hua Hsu

Theses

A progressive image transmission scheme based upon Laplacian pyramid structure is used for image coding over low-bandwidth channels. The filtering and differential pulse code modulation (DPCM) methods of image coding are generalized to allow quantization of the Laplacian images. Filtering is performed with a local, symmetric weighting function. The three different quantizers, (1) scalar quantizer, (2) memoryless vector quantizer (VQ), and (3) finite state vector quantizer (FSVQ), are used here to compare the results. In the receiver end, the image can be reconstructed using reverse procedure. The reconstructed image is not the same as the original image because of the …

Theoretical Model For The Images Formed By A Spherical Particle In A Coherent Imaging System: Comparison, Scott Alan Schaub, D. R. Alexander, J. P. Barton

Department of Electrical and Computer Engineering: Faculty Publications

A simple theoretical model is presented that allows calculation of the image produced by a spherical absorbing particle illuminated by monochromatic, coherent laser light. Results presented in this paper are restricted to a singe-lens imaging system, although generalization to more complex imaging system configurations would be straightfoward. The method uses classic Lorenz-Mie scattering theory to obtain the electromagnetic field external to an absorbing spherical particle and a Fourier optics approach to calculate the intensities in the image plane. Experimental results evaluating focus characteristics are examined for 50 um diameter water droplets using an N2 laser imaging system in conjunction with …

Modeling The Electromagnetic Radiation From Electrically Small Table-Top Products, Todd H. Hubing, J. Frank Kaufman

Electrical and Computer Engineering Faculty Research & Creative Works

It is noted that the most difficult radiated electromagnetic interference (EMI) problems with table-top products often occur at frequencies where the maximum dimensions of the product are much smaller than a wavelength. Electrically small table-top products tend to be much more efficient radiation sources than dipole source models would predict, and the radiation is generally much more difficult to contain than other types of EMI source models indicated. The ways in which electrically small sources radiate are investigated, and a technique for modeling electrically small table-top products that have power or signal cables is proposed. The end-driven wire model is …

Versatile Potentiostat With Optional Computer Control, Gary L. Fuller, William A. Russell Jr., Roger M. Hawk, James D. Wilson, P. D. Bratton

Journal of the Arkansas Academy of Science

A versatile potentiostat which can supply a maximum of 125 ma is described. The potentiostat uses readily available electronic components and an interface is detailed which allows the potentiostat optional computer control.

Computer-Controlled Programmable Pulse Generator For A Jeol Jnm-Ft-1a Radio Frequency Amplifier Section Of A Nuclear Magnetic Resonance Spectrometer, William H. Russell, Roger M. Hawk

Journal of the Arkansas Academy of Science

A microprocessor controlled programmable pulse generator was specifically designed to interface with the JEOL JNM-FT-1 A Radio Frequency (RF) section of a nuclear magnetic resonance (NMR) spectrometer. The programmable pulse generator was programmed and controlled by an IBM compatible computer. Statis rams were utilized as the programmable pulse generator's on board memory which were used to store the pulse sequences. Pulse widths can be programmed from 0.2 microseconds to 14.3 minutes. The JEOL RF section is unique in that it allows the pulse generator to control the phase of the RF transmitted to the NMR probe and whether the sample …

Consequences Of Valley Filtering On Abrupt Junction Algaas/Gaas Heterojunction Bipolar Transistors, Amitava Das, Mark S. Lundstrom

Department of Electrical and Computer Engineering Faculty Publications

Electron transport in AlGaAs/GaAs heterojunction bipolar transistors with compositionally abrupt emitter‐base junctions is examined. Transport across the abrupt emitter‐base heterojunction is treated quantum mechanically, and the Monte Carlo technique is used to study transport through the base. Although there is a sizeable population of upper‐valley electrons in the bulk emitter, the AlGaAs/GaAs heterojunction is found to favor the injection of Γ‐valley electrons into the base. This valley filtering effect enhances device performance by reducing base transit time, but quantum mechanical tunneling lowers the average energy of the injected flux which increases base transit time. The design of a heterojunction bipolar …

The Multiprocessor System With A Fairly Weighted Global Bus Arbitration Circuit, Shinobu Doi

Theses and Dissertations

The objective of this thesis is to investigate various multiprocessor system structures and to implement and test the resultant system configuration that offers high reliability and availability, ease of expansion, ease of programming, and increased computing performances. The resultant system is a MC68000 based tightly coupled multiprocessor system with large local memories and local I/Os, arbitrated by a specially designed arbitration circuit to implement pseudo random global bus granting. Each of the computer modules is an enhanced independent uniprocessor system with channel access switches to access the global memory. In its multiprocessor mode one computer module cooperates with the other …

Design Of The Electronics And Optics Needed To Support Charge-Coupled Devices : A Project Report ..., Kah Yep Zee

University of the Pacific Theses and Dissertations

Over the last five years, charge-coupled devices (CCD) have been improved dramatically in terms of sensitivity, manufacturability and particularly, cost. This has enabled them to be used economically in many more industrial and commercial electronic imaging processes. They are found in products ranging from video cameras to satellite-based camera systems. This has sparked my interests in these devices, and with a great deal of encouragement from Dr. Turpin, I decided to base my Master's thesis/project on a CCD. The project was mainly based on the design of the electronics and optics needed to support a CCD. The particular circuit design …

Algorithms For Multi-Channel Dtmf Detection For The We Dsp32 Family, Steven L. Grant, J. Hartung, G. L. Smith

Electrical and Computer Engineering Faculty Research & Creative Works

The authors describe two DTMF (dual-tone multiple frequency) detection algorithms that are highly efficient in the use of both real time and memory. The first algorithm is based on linear prediction (LP) and can be used to implement up to 32 DTMF detectors on a single 25-MHz NMOS WE DSP32. Using a 50-MHZ WE CMOS DSP32C, up to 45 detectors can be implemented. The second algorithm is based on a slight modification of the Goertzel algorithm and can be used to implement up to 16 DTMF detectors on a single DSP32 and up to 32 detectors on a DSP32C. In …

Speech Synthesis Using A Digital Modulation Scheme On The Ibm Personal Computer, John Glenn Wallace

Masters Theses

"Previously the primary output interface that users of personal computers have had available to them were limited to the crt or the printer. This paper presents a method for implementing a voice synthesizer on an IBM personal computer using only the hardware already contained in the personal computer. Presented is a modulation method which can be used with the IBM to obtain good quality voice output. The method consists of 3 parts, 1) sampling and recording the voice, 2) processing and filtering these samples and 3) using these processed samples to drive the speaker. A description of the hardware used …

Automatic Color Segmentation Of Images With Application To Detection Of Variegated Coloring In Skin Tumors, Scott E. Umbaugh, Randy Hays Moss, William V. Stoecker

Electrical and Computer Engineering Faculty Research & Creative Works

A description is given of a computer vision system, developed to serve as the front-end of a medical expert system, that automates visual feature identification for skin tumor evaluation. The general approach is to create different software modules that detect the presence or absence of critical features. Image analysis with artificial intelligence (AI) techniques, such as the use of heuristics incorporated into image processing algorithms, is the primary approach. On a broad scale, this research addressed the problem of segmentation of a digital image based on color information. The algorithm that was developed to segment the image strictly on the …

A 68000-Based Produce Sorting Microcomputer : Graduate Clinical Research Master's Report, Ramzi Albert Haidamus

University of the Pacific Theses and Dissertations

This report discusses in great detail the various research, design, and development stages of the Produce Sorting Microcomputer developed for HAGAN ENGINEERING Inc. The two-semester Clinical Research project has been approved by the graduate committee at the School of Engineering at the University of the Pacific and fulfills the requirements towards a Master Degree in Electrical Engineering.

The project was selected based on its complexity, feasibility, the time span it required to complete, and its relevance to the area of real time microcomputer design. In addition, the design constraints and specifications were to be dictated solely by HAGAN ENGINEERING Inc. …

The Effects Of Bandwidth Limiting Tuning Elements On A Synchronously Pumped Mode-Locked Dye Laser, Bahram Zandi

Dissertations and Theses

In this study an improved description of the bandwidth limiting tuning filters has been introduced into a semiclassical model for a synchronously pumped mode-locked dye laser system. This model is an improvement over the traditional rate equation approach since it has detailed representations of the energy levels, rotational distribution, and coherence effects. The new set of equations has been solved numerically using the best available values for the various parameters, and autocorrelations have been computed for a range of different length detuning and bandwidth limiting elements. In the experiments, an acousto-optically mode-locked argon ion laser is used to synchronously pump …

Ultrashort Pulse Production In Synchronously Pumped Mode-Locked Dye Laser Systems, Duncan Leo Macfarlane

Dissertations and Theses

The concern of this dissertation is the understanding and improvement of a class of lasers that is responsible for some of the shortest optical pulses available today. In particular, we seek ways to produce from synchronously pumped mode-locked dye laser systems, shorter pulses of higher intensity with improved pulse-to-pulse consistency. Specific topics.that are discussed herein include the study of the role of the pump pulse in synchronously pumped mode-locked lasers, the study of the pulse shaping and shortening due to an intracavity saturable absorber, and the study of a fundamental pulse train instability associated with these lasers.

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 …

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 …

A Structured Light Method For Sensing Alignment During Automated Truss Assembly, Jayesh K. Champaneri

Electrical & Computer Engineering Theses & Dissertations

A new method using structured light is proposed to obtain visual feedback information for aligning two cylindrical beams. For a robotic system employed to perform alignment operations in real time it is essential that the accompanying vision system does not pose a heavy burden on the computing machinery and reduce the overall speed of operation. The method proposed here involves two stripes of light projected on each cylinder. One picture frame is sufficient to completely determine the position of the cylinder in space. An experiment was conducted to demonstrate the principle of this method. Results showed that the errors involved …

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 …

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 …

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 …

The Lunar Date Of Ramesses Ii, Lee W. Casperson

Electrical and Computer Engineering Faculty Publications and Presentations

Due largely to the efforts of R. A. Parker, the various calendars used in Egypt are now fairly well understood. Dates which the Egyptians expressed in both their civil and lunar calendars can sometimes be determined exactly, and the study of such dates has been extremely important in efforts to establish an accurate Egyptian chronology. However, the successful use of this method obviously depends on one's ability to reconstruct accurately the astronomical and observational conditions on which the lunar calendar was based. The author re-examined the methods used to calculate lunar dates and have suggested some ways in which those …

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 …