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A Method For The Identification Of Parameters In Nonlinear Time-Varying Discrete Systems, Somo Coulibaly

Theses

The purpose of this thesis is to present a new technique for estimating the unknown parameters of nonlinear discrete time-varying systems.

The method is based on the model-reference control system where the model and the plant are controlled to exhibit the same output trajectory. The model is chosen to be linear and stationary. To develop the procedure of identification we assume that the structure of the nonlinear system is known and all the measurements are free of noise. A feedback input is adapted to improve the scheme. This scheme can be used to simultaneously identify the parameters when the control …

Modeling And Analysis Of Switching Dc-To-Dc Converters, Suresh Hariharan

Theses

Modeling and analysis of switching dc-to-dc converters has been achieved through several techniques. The state space averaging technique is valid only for disturbances which are less than one-tenth the switching frequency. The discrete technique does not yield accurate results. In this thesis a new approach to the stability analysis of switching regulators has been discussed and the model is far more accurate than the state space averaging technique or the discrete technique. It can be easily programmed into any computer and the results compare well with the experimental results. It also gives a good insight into the design of the …

Optimization Of The Sputtering Technology For Preparation Of Hg1-[Subscript X] Cd[Subscript X] Te Heterojunction Diodes, Kyriacos Kokkinos

Theses

The deposition of (Hg_1-xCd_x)Te onto Si and (Hg_1-yCd_y)Te (x>y) substrates by rf triode sputtering was studied. Ionized mercury vapor, in the 0.6 to 1.2 micron pressure range, was used to bombard pressed-powder targets, consisting of HgTe and CdTe particles, with effective target x value of 0.3, 0.35, and 0.4. The sputtering procedure, parameters, and system were modified to optimize film characteristics. Higher substrate temperature (270°C) was required to obtain metallic gray films with x>0.3. With substrate temperatures less than 270°C and deposition rates 0.5-1.0 micron per hour the films were …

Reliability Screening Of Transformers, Bharat M. Shah

Theses

The purpose of this project is to study screening of components from the reliability point of view. The component used is electronic transformer. The screen chosen is Electrical Noise generated in the transformer insulation system and the failure mode selected is leakage current in the transformer insulation.

Experiments were conducted to monitor electrical noise generated due to partial ionization of the tiny air gaps in the transformer insulation. The voltage stress, regiured to be applied to the insulation system, for constant 59 units of noise, recorded for the sample of three hundred seventeen transformers.

The voltage readings were analyzed statiscally …

Performance Comparison Of Digital Communication Signaling Schemes, Hiroshi Okusawa

Theses

The intent of the work "Performance Comparison of Digital Communication Signaling Schemes" is to consider various signaling schemes for digital communication and their relative performances.

In order to gain a better perspective of the overall problem of digital communication signaling, the most basic ideas, such as conceptual techniques for the generation and detection of modulated signals, are outlined and provided.

The primary measure of performance -for a digital communication system is the error rate. Emphasis is placed on analyzing the probability of error for various idealized signaling schemes.

Three-Reflection Halfwave And Quarterwave Retarders Using Dielectric-Coated Metallic Mirrors, T. F. Thonn, R. M.A. Azzam

Electrical Engineering Faculty Publications

A design procedure is described to determine the thicknesses of single-layer coatings of a given dielectric on a given metallic substrate so that a specified net phase retardance (and/or a net relative amplitude attenuation) between the p and s polarizations is achieved after three reflections from a symmetrical arrangement of three mirrors that maintain collinearity of the input and output beams. Examples are presented of halfwave and quarterwave retarders (HWR and QWR) that use a ZnS-Ag film-substrate system at the CO₂-laser wavelength λ = 10.6 µm. The equal net reflectances for the p and s polarizations are computed …

Power Characteristics Of Single‐Mode Semiconductor Lasers, Jaroslava Z. Wilcox, Lee W. Casperson

Electrical and Computer Engineering Faculty Publications and Presentations

The basic aspects of power calculations for high‐gain semiconductor lasers are briefly reviewed, and a straightforward one‐dimensional model is described. The relative importance of spontaneous emission, distributed losses, band‐to‐band absorption, and high single‐pass gain are investigated in detail.

Inverting The Ratio Of The Complex Parallel And Perpendicular Reflection Coefficients Of An Absorbing Substrate Using A Transparent Thin-Film Coating, R. M.A. Azzam

Electrical Engineering Faculty Publications

An absorbing substrate can be coated with a transparent thin film of refractive index N₁ (within a certain range) and thickness d such that the ratio of complex reflection coefficients for the p_and s polarizations of the film-covered substrate ρ = R_p/R_s is the inverse of that of the film-free substrate ρ¯ = R¯_p/R¯_s at an angle of incidence ø. A method to determine the relationship among ø, N₁, and d that inverts ρ (i.e., makes ρ = 1/ρ¯) for a given substrate at a given wavelength is described and is …

Inverting The Ratio Of The Complex Parallel And Perpendicular Reflection Coefficients Of An Absorbing Substrate Using A Transparent Thin-Film Coating, Rasheed M.A. Azzam

Electrical Engineering Faculty Publications

An absorbing substrate can be coated with a transparent thin film of refractive index N₁ (within a certain range) and thickness d such that the ratio of complex reflection coefficients for the p_and s polarizations of the film-covered substrate ρ = R_p/R_s is the inverse of that of the film-free substrate ρ¯ = R¯_p/R¯_s at an angle of incidence ø. A method to determine the relationship among ø, N₁, and d that inverts ρ (i.e., makes ρ = 1/ρ¯) for a given substrate at a given wavelength is described and is …

A 250-Kv Two-Pulse Modulator For The Gas Flow Switch Test Facility, David Michael Barrett

Electrical & Computer Engineering Theses & Dissertations

High-pressure spark gap switches are often used in pulsed power systems because of their high power capabilities. Unfortunately, these switches cannot be operated at high repetition rates because of the time required for the switch to recover. However, the recovery rate of a spark gap may be improved by flowing a gas through the interelectrode region so as to remove the hot gases and debris.

A test facility has been designed and constructed at Old Dominion University to evaluate the performance of gas-flow spark gap switches operating over a wide range of voltages and flow parameters. The facility consists of …

Wetlands Preservation And The Protection Of Endangered Species As Limits On Western Water Development, A. Dan Tarlock

The Federal Impact on State Water Rights (Summer Conference, June 11-13)

25 pages.

[Section] 404 Panel Discussion, Gregory J. Hobbs, Jr.

The Federal Impact on State Water Rights (Summer Conference, June 11-13)

5 pages.

Supplemental materials. Includes proposed bill language for Department of the Interior appropriations bill. Outline of key events and dates in the history of water law.

Panel: Section 404 Of The Clean Water Act And Section 7 Of The Endangered Species Act: Potential Impacts On Water Supplies [Supplemental Materials], Wendy C. Weiss

The Federal Impact on State Water Rights (Summer Conference, June 11-13)

57 pages.

Supplemental materials. Includes text of Riverside Irrigation District v. Andrews, 568 F.Supp 563 and Opening Brief of Plaintiff-Intervenor-Appellants in Riverside Irrigation District v. Andrews, Cases No. 83-2114, 83-2115, 83-2119, 83-2230, April 3, 1984.

Groundwater Control Programs Affecting Water Development, Arthur L. Littleworth

The Federal Impact on State Water Rights (Summer Conference, June 11-13)

19 pages.

Ferc, Purpa And The Federal Power Act, Lawrence J. Wolfe

The Federal Impact on State Water Rights (Summer Conference, June 11-13)

62 pages.

Contains references.

The Case For A Legislative Solution To Indian Water Claims, James M. Bush

The Federal Impact on State Water Rights (Summer Conference, June 11-13)

57 pages.

Reserved Water Rights Of Indian Allotments, Richard B. Collins

The Federal Impact on State Water Rights (Summer Conference, June 11-13)

10 pages.

Contains references.

Instream Flows As Reserved Rights On Federal Reservations After United States V. New Mexico, Hank Meshorer

The Federal Impact on State Water Rights (Summer Conference, June 11-13)

10 pages.

Effects Of The Clean Water Act On Water Availability And Development, Paula C. Phillips

The Federal Impact on State Water Rights (Summer Conference, June 11-13)

12 pages.

Introduction To Reserved Water Rights, Ralph W. Johnson

The Federal Impact on State Water Rights (Summer Conference, June 11-13)

16 pages.

Indian Water Rights In The Supreme Court: A Review And Preview, Louis F. Claiborne

The Federal Impact on State Water Rights (Summer Conference, June 11-13)

12 pages.

Agenda: The Federal Impact On State Water Rights, University Of Colorado Boulder. Natural Resources Law Center

The Federal Impact on State Water Rights (Summer Conference, June 11-13)

Conference organizers and/or speakers included University of Colorado School of Law professors James N. Corbridge, Jr., David H. Getches, Lawrence J. MacDonnell and Richard B. Collins.

In general, water rights are a matter of state law. However, the availability and development of water are affected by important federal rights, policies and programs. In this conference, an outstanding group of private practitioners, government representatives and academics consider this important topic.

Developments In Federal Water Policies And Programs, Harold W. Furman Ii

The Federal Impact on State Water Rights (Summer Conference, June 11-13)

14 pages.

Role Of The State Courts In Adjudicating Indian Water Rights, Jon L. Kyl

The Federal Impact on State Water Rights (Summer Conference, June 11-13)

39 pages.

Negotiation As A Means Of Quantifying Indian Water Rights, Joseph R. Membrino

The Federal Impact on State Water Rights (Summer Conference, June 11-13)

88 pages.

Contains attachments.

Microcomputer Controlled Instrumentation System For Studies Of Metabolic Changes In Rats, Murat Dertlioglu

Theses

The system measures the respiratory exchange in rats in a controlled experiment. An interface unit provides data, received from several measurement instruments such as gas analyzers, an electronic flowmeters, electronic thermometer and an electronic hygrometer, to the computer. The data is gathered from different chambers in a multiplexed mode.

The computer samples the chambers sequentially and prints out the results and stores them on the disk. The sampling duration of each chamber and the number of the rats to be tested can be programmed. The system can perform experiments with twelve animals, in the following arrangments, either one group of …

The Detection Of Partial Discharges In Transformer Oil, Gerald J. Fitzpatrick

Theses

The level, meaning the number and the intensity Of partial discharges that occur in transformer oil per time period of applied pulse when a high voltage is applied can be used as a measure of the quality and remaining life of the oil. The level of partial discharges at a given applied voltage can be correlated with the degree of contamination of the oil by impurities such as water and conductive particles and can be used as an indicator of the proximity of the oil to breakdown. There are several approaches to the detection of partial discharges, e.g., acoustic measurements, …

Performance Modeling And Simulation Of Multiple Microcomputer Systems, Moorthy Narayana Hariharan

Theses

Multiple processor systems are the logical choice for applications demanding high computing power, throughput and reliability. Moderately coupled Multiple Microprocessor systems can be applied to a variety of applications demanding high performance. The structure of Multiple Microprocessor systems is examined. Various interconnection structures are analysed for performance comparisons.

Queueing theory is a powerful tool in modeling and analysing Computer systems. Queueing models are developed for popular Multiple processor interconnection topolog es like the Shared memory, Shared bus, Star and Loop configurations.

The usefulness of Digital computer Simulation techniques in estimating the performance of Multiple processor systems is demonstrated through a …

An Investigation Of Characteristics Of Blood Velocity In A Simulated Circulation System, Yung-Gang Wu

Theses

The major objective of this thesis is to find the relationship between the blood velocity and the stenosis of the vessel. Tests were performed with different degrees of stenosis at varied logitudinal positions from the testing probe in the vessel of a Z-80 microprocessor controlled artificial circulation system.

Three methods were used to detect the velocity in the vessel: continuous wave Doppler, Pulse Doppler, and a hot-film device. The first method can get the average velocity, while the latter two have the capability to find a velocity profile, and all are important indicators to the arterial occlusion phenomenon.

An analysis …

Magnetohydrodynamic Synchronous Generator With Exhaust Divertor Plasma Of Fusion Reactor, Prabir Kumar Majumdar

Theses

It is the intent of this thesis to develop design concept of a MHD-Synchronous generator for generation of A-C electric power utilizing the exhaust divertor plasma of Tokomak fusion reactor.

The main physical structure of the MHD-Synchronous generating system consists of (1) a linear induction accelerator at the divertor channel to accelerate the plasma velocity sufficient enough to provide rotational effect on the exhaust cylinder by turbine action; (2) a D-C field coil as a source of magnetic field at the entrance of the exhaust chambers; (3) turbine blade on the upper portion of the cylindrical current sheet and (4) …