Electrical and Computer Engineering Commons^™

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.

An Exact Analysis For Efficient Computation Of Random-Pattern Testability In Combinational Circuits, Sharad C. Seth, Bhargab B. Bhattacharya, Vishwani Agrawal

School of Computing: Conference and Workshop Papers

Experimental evidence shows that low testability in a typical circuit is much more likely due to poor observability than poor controllability. Thus, from theoretical and practical standpoints, it is important to develop an accurate model for observability computation. One such model, in terms of supergates, is proposed in the first part of this paper thus complimenting our earlier work. It is now possible to obtain exact random-pattern testability for each line in a circuit.

The second part of the paper analyzes the supegate structure of a circuit from a graph theoretic viewpoint. Finding a supergate is related to determining the …

Investigation Of Electronic Holography Using Spice Computer Simulation Experiments, Monish Ranjan Chatterjee

Electrical and Computer Engineering Faculty Publications

Using SPICE experiments, it has been possible to verify most of the important aspects of electronic holography. The generation and properties of dynamic echoes under different types of nonlinearities have been extensively tested, and some new information has been garnered in the process. The case of pulse and generalized memory echoes has also been tested, and the results have been fairly satisfactory. Most of all, the simplicity with which the intriguing concept of memory echoes has translated into the circuit implementation on SPICE, and the closeness of the results to predicted behavior have been somewhat of a pleasant surprise.

Since …

An Investigation To Improve Linear Predictive Vocoder Pulse/Noise Excitation Models, Elizabeth Annella Martina Effer

Electrical & Computer Engineering Theses & Dissertations

The quality of synthetic speech from Linear Predictive (LP) vocoders is known to be degraded due to the lack of detail in the commonly used pulse/noise excitation model. In this investigation, it was hypothesized that this degradation is due to the lack of precise timing information in the pulses and to the constraint that each short-time segment of excitation be either an impulse train or white noise. Accordingly, more complex excitation models were implemented using precise timing from peaks in the residual and a mixture of pulses and noise. Since the LP residual is known to be the perfect excitation …

Randomized Routing On Fat-Trees, Ronald I. Greenberg

Computer Science: Faculty Publications and Other Works

Fat-trees are a class of routing networks for hardware-efficient parallel computation. This paper presents a randomized algorithm for routing messages on a fat-tree. The quality of the algorithm is measured in terms of the load factor of a set of messages to be routed, which is a lower bound on the time required to deliver the messages. We show that if a set of messages has load factor lambda on a fat-tree with n processors, the number of delivery cycles (routing attempts) that the algorithm requires is O(lambda+lgnlglgn) with probability 1-O(1/ …

An Inventory Of Maine's Telecommunications System, Maine State Planning Office

Maine Collection

An Inventory of Maine's Telecommunications System

Prepared for the Maine State Planning Office by Joseph M. Chaisson and Valerie Lamont of the Telecommunications Research Program at Westbrook College in Portland, Maine. July, 1985.

"The Primary purpose of this report is to provide information for Governor Brennan's Task Force on Telecommunications. The inventory also can be widely used as a reference by persons and organizations concerned with providing telecommunications services in Maine."

Contents: Introduction / Local Telephone Service / Mobile Telephone Service / Digital Termination Service / Cable Television / Paging Systems / Intra-State (Intra-LATA) Public Services / Intra-State (Intra-LATA) Private …

Study Of Mo, Au, And Ni Implanted Molybdenum Laser Mirrors By Spectroscopic Ellipsometry, Paul G. Snyder, George H. Bu-Abbud, Jae Oh, John A. Woollam, David Poker, D. E. Aspnes, David Ingram, Peter Pronko

Department of Electrical and Computer Engineering: Faculty Publications

The implantation of 150 kev molybdenum ions into polished molybdenum laser mirrors is found to increase the complex dielectric constant in the visible spectrum. Analysis using the Bruggeman effective medium approximation demonstrates that the increase is due to surface smoothing and that the surface is made nearly atomically smooth by a fluence of 5 x 10¹⁵ /cm². Implantation of Au at 1Mev caused considerable microscopic roughening, as well as a change in the bulk optical properties. 3 MeV Ni ion implantation caused only a slight surface roughening. A thin dielectric film (probably a hydrocarbon) is found to …

Microcomputer Mrp In Three Months: Photon Kinetics, Wayne W. Wakeland

Complex Systems Faculty Publications and Presentations

Information about the company Photon Kinetics, a small, privately-held manufacturer of fiber optics test equipment, located in Beaverton, Oregon.

Self‐Refraction Of Nonlinear Capillary‐Gravity Waves, Partha P. Banerjee, Adrianus Korpel, Karl E. Lonngren

Electrical and Computer Engineering Faculty Publications

Self‐refraction effects have been observed during the propagation of deep‐water capillary‐gravity waves. The observations are shown to be in qualitative agreement with the theory of self‐focusing and defocusing in a cubically nonlinear medium in the presence of diffraction.

Subharmonic Generation By Resonant Three‐Wave Interaction Of Deep‐Water Capillary Waves, Partha P. Banerjee, Adrianus Korpel

Electrical and Computer Engineering Faculty Publications

Subharmonic generation has been observed during the propagation of deep‐water capillary waves. The observations are shown to be in agreement with the theory of degenerate resonant noncollinear three‐wave interaction in a nonlinear, dispersive medium.

On The Uniqueness Of Solution Of Magnetostatic Vector‐Potential Problems By Three‐Dimensional Finite‐Element Methods, O. A. Mohammed, W. A. Davis, B. D. Popovic, T. W. Nehl, Nabeel Demerdash

Electrical and Computer Engineering Faculty Research and Publications

In this paper, particular attention is paid to the impact of finite‐element approximation on uniqueness and to approximations implicit in finite element formulations from the uniqueness requirements standpoint. It is also shown that the flux density is unique without qualifications. The theoretical and numerical uniqueness of the magnetic vector potential in three‐dimensional problems is also given. This analysis is restricted to linear, isotropic media with Dirichlet Boundary conditions. As an interesting consequence of this analysis it is shown that, under usual conditions adopted in obtaining three‐dimensional finite‐element solutions, it is not necessary to specify div Ā in order that Ā …

A Critical Study Of Nonlinear Echo Phenomena, Monish Ranjan Chatterjee

Electrical and Computer Engineering Faculty Publications

The present thesis attempts to give a concise and critical account of the evolution of the echo phenomena over the last thirty years. Starting with spin and photon echoes, which were among the earliest to be observed and studied, the thesis explores the experimental findings and the models proposed in connection with the more contemporary echo experiments, viz. those involving electroacoustic or polarization echoes in single and polycrystalline piezoelectric materials and in powders. Although the investigations regarding the various mechanisms of short and long term echo formation are by no means complete, a coherent picture is beginning to emerge as …

Atomic Hydrogen Storage, John A. Woollam

Department of Electrical and Computer Engineering: Faculty Publications

Atomic hydrogen, for use as a fuel or as an explosive, is stored in the presence of a strong magnetic field in exfoliated layered compounds such as molybdenum disulfide or an elemental layer material such as graphite. The compound is maintained at liquid temperatures and the atomic hydrogen is collected on the surfaces of the layered compound which are exposed during delamination (exfoliation). The strong magnetic field and the low temperature combine to prevent the atoms of hydrogen from recombining to form molecules.

Electronic Properties Of Metal Chloride Intercalants Of Graphite*, **, John A. Woollam, M. B. Dowell, A. Yavrouian, A. G. Lozier, G. Matulka

Department of Electrical and Computer Engineering: Faculty Publications

The Shubnikov-deHaas (SdH) effect has been used to study the electronic properties of graphite intercalated with PdC1₂ (stage 3), FeC1₃ (stages 2, 4, 6, and 11), CuC1₂ (stage 1), and WC1₆ (stage 5). For the palladium chloride, ferric chloride, and copper chloride intercalants the SdH spectra are similar: these show frequencies of approximately, 27, 80, 380, and 550 Tesla for fields parallel to the c-axis. The effective masses have been measured for each of these carriers, and are of the order of 0.1 m₀, where m₀ is the free electron mass. These carriers …

Some Facts And Prospects For The Establishment Of Television Broadcasts In Mainland Tanzania, H. R. Mgombelo

Tanzania Journal of Engineering and Technology (TJET)

Abstract

Atomic Hydrogen Storage Method And Apparatus, John A. Woollam

Department of Electrical and Computer Engineering: Faculty Publications

Atomic hydrogen, for use as a fuel or as an explosive, is stored in the presence of a strong magnetic field in exfoliated layered compounds such as molybdenum disulfide or an elemental layer material such as graphite. The compound is maintained at liquid helium temperatures and the atomic hydrogen is collected on the surfaces of the layered compound which are exposed during delamination (exfoliation). The strong magnetic field and the low temperature combine to prevent the atoms of hydrogen from recombining to form molecules.

Sio2-Si Film-Substrate Single-Reflection Retarders For Different Mercury Spectral Lines, A.R.M. Zaghloul, R.M.A Azzam

Department of Electrical and Computer Engineering: Faculty Publications

Design parameters for SiO₂- Si film-substrate single reflection retarders for several mercury spectral lines are presented. An example of an angle-of-incidence tunable retarder (AITR) capable of multiple wavelength operation (MWO) is reported Simple, approximate formulae for calculating film-substrate retarder design parameters (least film thickness d' and incidence angle) are presented.

Electronic Color Scanners, Kenneth Francis Hird

Graduate Research Papers

Process color photography has been continually developing for many years. In fact, color printing techniques are still benefiting, through additional sophisticated requirements, and from a discovery made about 300 years ago. At that time Sir Isaac Newton, British scientist, mathematician • and philosopher, placed a glass prism in the path of a narrow beam of sunlight entering his room through a pinhole in an opaque window shade. He determined that ordinary white light is a mixture of colored lights.

Unfortunately, in practice, ideal pigments for three-color inks do not exist and this impasse greatly complicates the job for the photo-processor. …

Hall Effect Magnetometer, John A. Woollam, Harry A. Beale, Ian L. Spain

Department of Electrical and Computer Engineering: Faculty Publications

A magnetometer utilizing a single crystal of Bi²Se³ having a rhombohedral crystal structure is described along with a method for making such a device. The Bi²Se³ has a positive or negative Hall coefficient and a carrier concentration of about 10¹⁸to10²⁰ per cubic centimeter.

Digital Video Display System Using Cathode-Ray Tube, George M. Low, Arthur I. Zygielbaum, Warren L. Martin, Alexander Engel

School of Natural Resources: Faculty Publications

A digital video display system (DWDS) is disclosed for display of image, alphanumeric and other data on a cathode-ray tube (CRT) with sequential raster scan and two, four or eight gray shades. The DVDS includes a central processing unit for ac tivating the system, selecting the X (horizontal axis) and Z (in tensity modulation) modes, and designating the starting loca tion of two successive rasters of data from a memory accessed by a data multiplexer subsystem (DMS). At the end of each raster, the DMS interrupts the computer for a new starting lo cation of a raster of data to …

Systems Reliability Using The Flow Graph, Kenneth Edward Farrier

Dissertations and Theses

The problem of calculating the reliability of a complex system of interacting elements is delineated to a linear system, no element of the system having a reliability distribution in terms of any other e1ement of the system, where only one path is taken through the system at a time. A precise definition is then developed to specify the reliability of the linear, single path at a time, system. A precise and concise generating function is found that effortlessly produces the reliability of the linear, single path at a time, system directly from the reliability flew graph of the system.