Engineering Commons^™

A Log-Spiral, Radiating-Line Antenna, James L. Drewniak, P. E. Mayes, D. Tanner, R. Waller

Electrical and Computer Engineering Faculty Research & Creative Works

No abstract provided.

Measurements Of Basic Semiconductor Properties, Abdolreza Ariantaj

Theses

Mobility, resistivity, and total impurity concentration of several purchased p-type silicon samples with known resistivities were measured by Hall effect, experiments utilizing the Van Der Pauw method. The silicon samples will serve as Hall effect standards for future measurements on other semiconductor materials, particularly gallium nitride ion cluster beam (ICB) deposited thin films. The samples which were Freshly etched with hydrofluoric acid had measurement values of 455 cm ² / V.sec, 45.9 Ω cm, and 2.6 X 10¹⁴ cm³ for mobility, resistivity, and total impurity concentration, respectively. The mobility values were within 9.9 per cent, of the published values …

Effect Of Humidity And Moderate Temperature On Microcircuit Failure, Antoine Mikhayel Chaia

Theses

The increased use of microprocessors has brought forth many questions concerning the reliability of these devices.

This research discuss the TTL integrated circuit failure rates, and provides information on the effects of temperature, device complexity and packaging on TTL failure rates under storage condition of 100% R.H. (Relative Humidity) and 100°C and no added humidity at 100°C. Other factors which can affect failure rate are also discussed, including designs, materials process.

Approximately 200 microcircuits of TTL (74LS00) were subjected to extend life testing at 100°C; where 125 chips are tested at 100°C ± 2° and no added humidity and the …

Nervous System Simulation, Jian Chen

Theses

This thesis deals with the nervous system simulation. The Hodgkin-Huxley model and Stein's model are used as basic tools. The author has tried to describe some practical problems by mathematical models.

First, the horse-shoe crab eye is investigated. Light intensity is reported to the brain by the firing frequency of the photoreceptoe. A Poisson process is used to simulate the stimulus to the receptor. The result of the stochastic model coincides with the theoretical one: receptor overlapping decreases the resolving power of the eye; and the lateral inhibition compensates the effect of overlapping.

Second, a nerve muscle model was set …

Waveform Analysis Using A Micro Computer, Dakshina K. Murthy

Theses

Harmonic analysis through a micro computer was performed at Brookhaven National laboratory to determine the magnitude and extent of hormonic dIstortionon in their electrical power supply system. DT 2801 Hardware and MADCAP software were used to accomplish the Harmonic anylysis through forier transform.

Replacement Of Surface Ducted Rays Near Caustics With Guassian Beams, Carlos Javier Ruiz

Theses

Conventional approach to a solution of a wave propagation problem in an inhomogeneous medium is to utilize either rays or modes to represent the wave field. Asymptotic ray theory (ART) starts to fail in the vicinity of caustics due to rays experiencing many reflections. Even uniform representations do not properly correct this deficiency of rays when caustics start to pile up in the far range. One possible alternative is to replace these rays with modal bundles and remainders [1]. A promising technique using Gaussian Beams has been used to represent the total field due to a point or a line …

Design And Optimization Of Nmos Sense Amplifiers For Vlsi Drams, Nimish K. Shah

Theses

The aim of this thesis is to study and optimize the performance of NMOS sense amplifiers used in modern VLSI DRAMs.

Initially dynamic memory cells and popular sense amplifier circuits are surveyed.

A standard five transistor sense amplifier is later chosen for detailed analysis. Layout of the circuit is drawn to get the physical parameters. Using SPICE simulator, various effects of circuit parameters are studied. From these results optimal values of these parameters are arrived at.

Also an effort is made to derive theoretically equations for the latching time of a post amplifier which is the most important part in …

Multi-Channel Arrhythmia Analysis In The Clinical Exercise Electrocardiogram, Shi-Xiong Yang

Theses

This thesis studied methods of using 2 channel ECG signals for noise elimination and arrhythmia detection. Clinical data were recorded from patients stress tests and were stored on diskettes for off-line processing. Spatial velocity vector and noise estimation methods in addition to analog and digital filters were combined to remove the noise produced from different sources. Feature extraction and matched filter methods were employed for classification of normal and abnormal QRS complexs, while rhythm computing was used in addition for PVCs and other arrhythmia discrimination. This algorithm was tested on clinical stress test recordings and a computer simulated arrhythmia recording …

An 8052 Ah - Basic, Based Development System, Suresh Vishwanath Leley

Theses

This project exploits the latest in microcontrollers-an entire environment for developing and prototyping a microcontroller application. With one key chip, a little glue, and a Dumb terminal a powerful system is achieved at a vanishingly small cost. This "one chip" system is adequate for realizing a wide range of applications calling for a small computer or an embedded processor.

Besides economy of system cost, the turn around time from concept to functioning application can be extremely short, even when the development engineer is not particularly well acquainted with traditional assembly language and microprocessor development practices. This economy is achieved by …

Linearization Accuracy In Probabilistic Load Flow, Guan-Zhong Liang

Theses

This paper presents a linear load flow method which can be used for probabilistic load flow analysis. The method is based on least-square estimation. To estimate its accuracy in linear load flow calculations, the method and a previously developed linear load flow method are applied to a typical power system and the results evaluated. Comparable accuracy is noted.

An Analysis Of Minimum Shift Keying From The Viewpoints Of Quadrature Multiplexed And Multi-H Continuous Phase Modulation Signaling, Alfred Anthony De Seta

Theses

Minimum Shift Keying (MSK) is a bandwidth efficient modulation scheme which offers superior performance over Quadrature Phase Shift Keying (QPSK) and Offset Quadrature Phase Shift Keying (OQPSK). This paper discusses these modulation techniques from a quadrature multiplexed signaling viewpoint and compares them in terms of error performance, bandwidth properties and bandlimiting and hardlimiting effects. MSK is also considered as a special case of a multi-h Continuous Phase Modulation (CPM) signal and the Viterbi algorithm is presented as an optimal detection scheme for this class of signals. A computer simulation is performed with the VA as the detection mechanism for an …

A Computer Aided Manufacturing System For Small Quantity Prototype Board Production, Santiago Garcia-Perez

Theses

A matrix addressed manufacturing tool has been built, tested, and integrated in a system aimed to exploit wire-wrap wiring technology for protoboard production in small quantities. Extensive software exploits the power and economy of the personal computer as a superb manufacturing tool and documentation system. Computer graphics are used as a visual aid that takes advantage of the cognitive capabilities of the human mind and eliminates the boredom and high costs involved with heavy automation achieving instead a tolerable level of human engagement with significantly increased efficiency. The approach presented is new and delivers substantial gains in productivity. The software …

Realization And Implementation Of A Recursive Digital Convolution Algorithm In Cmos, Lik Tang Cheng

Theses

This thesis describes the implementation of a digital convolver. A recursive digital convolution algorithm was realised and implemented by using CMOS circuitry. This thesis also gives a technical overview of current CMOS processing technologies as well as various novel CMOS logic circuit techniques.

The Acquisition Of Direct Sequence Spread Spectrum Communication Systems, Anthony Donald Demeri

Theses

This Paper surveys different techniques of acquiring Direct Sequence Spread Spectrum Systems.

It classifies different systems, indicates the strongpoints and weakness of each, along with some applications.

One method, The Single Dwell Serial PN Acquisition System is then focused on in detail. The detail includes analysis of standard version, derivation of the mean time to acquire, the variance, the probability of detection and the probability of a false alarm.

In the last section of the paper the analytical results of the Single Dwell Serial PN Acquisition System shall be confirmed by computer simulation.

Reliability Studies On Solid Tantalum Electrolytic Capacitors By Means Of Accelerated Life Tests, Venkata R. Golthi

Theses

The purpose of this thesis is to understand the failure mechanisms in Solid Tantalum Capacitors encapsulated in plastic, and to suggest the precautionary measures that prevent the occurrence of these failures.

The reliability of Solid Tantalum Capacitors encapsulated in plastic is of considerable interest because in some applications where the mechanical accelerations or shocks are considerable the "better" "hermitically" sealed type are not able to sustain themselves. Poor adherence between the dielectric film and the base metal Tantalum under the conditions of sudden mechanical shocks, causes problems.

Our study was carried out in two different directions, theoretical and experimental. The …

The Dielectric Slab-Wedge Antenna, B. Keith Christensen

Theses

A theoretical model and numerical investigation of the directive gain of a dielectric slab-wedge radiator is presented. The model is based on a union of the classical dielectric slab equations, local mode theory, and equivalent current distribution treatments of the truncated dielectric slab and wedge geometries.

The far field is developed from the sum of two current distributions. The slab region, up to the transition plane between slab and wedge, is replaced by equivalent electric and magnetic surface current densities. The wedge contribution is developed from a volume polarization current distribution.

Conservation of power is used to approximate the field …

Computer-Aided Design Of A Waveguide To A Suspended Stripline Transition For Millimeter-Wave Applications, Hsin-Yen Peng

Theses

Realization of millimeter-wave systems on suspended striplines necessitates transitions from such lines into waveguides for measurements and other purposes. Transition can be obtained through coupling TE10 mode in the waveguide into a TEM mode in the suspended stripline. A continuous transition using tapered complementary unilateral finline and two gradually increasing conducting tapered ridges is studied here. The tapered region is modelled using a number of uniform sections with gradually changing cross sections. The junction separating the tapered section from the suspended stripline is modelled via physically and electrically continuous terminations. Physical continuity approach is more flexible for manufacturing purpose at …

On-Line Analysis Of Highly Coherent Brain Activity During Transcendental Meditation And Automated Biofeedback, Deepak Dinkerrai Rawal

Theses

Occurance of highly coherent brain activity (EEG) specific to the meditation has been reported in the literature. The present thesis is an effort to look into the mechanics of meditation using the recent technique of analysis of high coherence in the EEG. Based on previous work, reporting increased EEG coherence during practice of Transcendental Meditation, a closed loop model and hypothesis is proposed using biofeedback to close the loop. The hypothesis proposes that very high coherence in the EEG is a very significant neurophysiological parameter, reflecting instantaneous quality of meditation in the form of an average high coherence above threshold. …

Ray And Beam Representation Of The Glancing Phenomena, Michael Sotiriou Vogas

Theses

Asymptotic ray theory (ART) is a widely used method dealing with problems of wave propagation in an inhomogeneous medium. The main deficiency of ART is in transition regions where rays near caustics, glancing and critical incidence fail to represent the actual wave field. Ray bundles in such transition regions have been successfully replaced with modal bundles and remainders El] in well defined profiles. However , in practical problems it is difficult to implement modal representations and almost impossible to express remainders. Recently emerging Gaussian beam method (GBM) has shown promising results in representing the total field produced by a source …

Microcomputer Local Area Network Interface, David W. Juan

Theses

A Microcomputer Local Area Network Interface system for use in the study of Local Area Network has been built and tested. The special feature of the system is data transmission/receiving and error detection/recovery. The system adapted the International Standards Organization (ISO) Open System Interconnection COSI) model. It used the star topology and implemented the physical layer, data link layer and network layer. The results of the system indicated the data communications and resources—sharing between microcomputers.

Design And Evaluation Of Performance For The Multi-Microprocessor System, Sang-Soo Lee

Theses

A tightly coupled multiple-microprocessor with two MPU's that can be run at different clock speeds has been built and tested. The method of interconnection for this multiprocessor is a timeshared common bus with shared memories having a tightly coupled architecture. The signal timipg of the multiprocessor system for different speeds has been investigated using a logic analyzer for simulation modeling. The desired timing results have been obtained. According to the timing results, the simulation model for the General Purpose Simulation System has been correctly designed and performance of the multiprocessor system for the various clock speeds has been evaluated by …

Reliability Study Of Liquid Crystal Display, Kalpesh Mahendra Desai

Theses

The purpose of this thesis is to study the reliability of liquid crystal display under different temperature conditions. To accomplish this, accelerated life testing was done on the soft glass and the hard glass liquid crystal display units at 77 C and 85 C temperature without any added humidity or voltage.

As the current is a usefu1 indicator for probable wear of liquid crystal display, leakage current was measured at 0 hour, 1000 hours, 2000 hours and 3000 hours when the units have stabilized at room temperature.

The date shows higher spread for the hard glass units. This may indicate …

Maine Yankee Shutdown Assessment: A Report To Governor Joseph E. Brennan, Maine State Planning Office

Maine Collection

Maine Yankee Shutdown Assessment: A Report to Governor Joseph E. Brennan

Maine State Planning Office, Maine Office of Energy Resources, Maine Public Advocate

Executive Department - May 1986

Contents: Legal Process / Decommissioning Constraints and Costs / Public and Economic Costs and Benefits / Apprendices

Design And Applications Of A Graphics Package For The Hp1000 Computer., Hsiao-Chih George Lee

Electronic Theses and Dissertations

The objective of this thesis is to develop the FORTRAN subroutine PLOTER which is a general-purpose plotting tool to plot charts on a Hewlett Packard plotter. The programs RESP and INVLAP which can plot the frequency and time responses of system functions are modified to adopt the PLOTER subroutine and are stored of the HP1000-A900 minicomputer whose software, the GRAPHICS/1000, supports the graphics ability of PLOTER. This thesis describes the theories, functions, software techniques and operations of the PLOTER subroutine and the application programs RESP and the INVLAP. It also provides program listings and example plots.

Two-Step Optimal Thermal Generation Scheduling, B Fardanesh, F. Eugenio Villaseca

Electrical and Computer Engineering Faculty Publications

A new approach to the solution of the optimal thermal generation scheduling problem is presented. The problem is solved in two steps. As a first step, the optimal production schedule for the next day is obtained based on a daily load forecast, reserve capacity requirements, and present status of generating units. The second-step algorithm uses the results of the first step and adjusts the previous schedule to meet new constraints developed during the course of the day. Variable truncation dynamic programming is proposed as a new method to reduce computation effort. To eliminate the need for solving the …

Laser Pump And Probe Excited State Absorption Measurements, Shawpin Jong

Electrical & Computer Engineering Theses & Dissertations

A pump and probe technique was used to investigate triplet-triplet excited state absorption in solutions of the scintillators 2,5 diphenyloxazole (PPO) and 2,1 naphthyl,5 phenylzole (a-NPO) in several solvents.

KrF excimer radiation (248 nm) was used to pump the samples under investigation as well as a tunable dye laser which was used as the probe. Time-resolution was obtained by changing the optical path difference between the pump and probe beams.

Transient excited state absorption was measured in a wide spectral region between 330 nm and 600 nm, showing a peak at 400 nm for PPO solutions, and two …

A Unit Of Instruction In Fiber-Optic Communication, Ronald Struble

Graduate Research Papers

The purposes of this research project were to:

1. Review the historical developments, components, and applications of optical fiber in communications.

2. Develop a laboratory exercise to demonstrate fiber-optic communication.

3. Construct equipment to demonstrate the use of fiber optics in communication. This equipment is used in the laboratory exercise.

Evidence For Amphoteric Behavior Of Ru On Cdte Surfaces, D. N. Bose, S. Basu, K. C. Mandal, D. Mazumdar

Faculty Publications

No abstract provided.

Optimization Of Reactive Ionized Cluster Beam (R-Icb) Technique For Deposition Of Gan Films, Veronica S. Kyriacou

Theses

The deposition of GaN film onto glass substrate, using the Reactive - Ionized Cluster Beam deposition technique was studied. The creation of clusters is dictated by various parameters such as the vacuum pressure inside and outside the crucible, the crucible temperature, and the nozzle diameter of the crucible. Optimization of these parameters was experimentally studied, and deposition of gallium films on glass substrates was tried as a first step.

The direct heating method was used at first to get the 1100¬1300°C crucible temperature which was required for the creation of gallium clusters. Although different tungsten wire diameters and different number …

The Gpib User's Manual For Hx-40, Ding-Tang Li

Theses

A completed RS-232 to GPIB interfacing system has been built for HX-40 to master the GPIB oriented machine through its serial port. GPIB commands and data can be transfered between HX-40 and the slave station, which is a HP 3582A spectrum analyzer in this project. The data acquisition from serial to GPIB is done by a well-made GPNET mode 10 interfacing board in a transmitting rate of 9600 baud rate. GPNET exchanges data and commands with HX-40 through a RS-232 port, and passes them to the slave station through a GPIB port which is coordinated by GPIB protocol. A software …