Digital Commons Network^™

New Directions In Subband Coding, Y. Shoham, Steven L. Grant, N. Seshadri, R. V. Cox, S. R. Quackenbush, N. S. Jayant

Electrical and Computer Engineering Faculty Research & Creative Works

Two very different subband coders are described. The first is a modified dynamic bit-allocation-subband coder (D-SBC) designed for variable rate coding situations and easily adaptable to noisy channel environments. It can operate at rates as low as 12 kb/s and still give good quality speech. The second coder is a 16-kb/s waveform coder, based on a combination of subband coding and vector quantization (VQ-SBC). The key feature of this coder is its short coding delay, which makes it suitable for real-time communication networks. The speech quality of both coders has been enhanced by adaptive postfiltering. The coders have been implemented …

Microprocessor Controller For A Multi-Targets System, Shoeineng Lin

Theses

This thesis presents a microprocessor controller for a multi-targets system, which is designed by a direct digital control in the modern computer-aided manufacture system. It is made up of digital control theory, computer hardware configuration and software algorithm. An example is illustrated by IBM PC/XT computer. In this example, the control laws of three simple targets are developed and implemented by C-language. Simultaneously, the computer self-test routines, such as CPU, ROM etc, are developed by intel-8088 assembly language.

Two-Dimensionat Studies Of Streamers Fn Gases, S. K. Dhali, P. F. Williams

P. F. (Paul Frazer) Williams Publications

We present the results of two-dimensional computer simulations of streamer initiation and propagation in atmospheric pressure N₂. The simulation algorithm makes use of flux-corrected transport techniques and was used as a tool to study the solutions of the transport equations under conditions suitable for streamers, for which realistic analytic solutions are not known. We present and discuss conclusions about streamer transport based on the results of these studies. Finally, we present a novel method of checking on the numerical accuracy with which the algorithm solves the transport equations.

Constraint On The Optical Constants Of A Transparent Film On An Absorbing Substrate For Inversion Of The Ratio Of Complex P And S Reflection Coefficients At A Given Angle Of Incidence, R. M.A. Azzam, M. A. Habli

Electrical Engineering Faculty Publications

An absorbing substrate of complex refractive index n₂-jk₂ can be coated by a transparent thin film of refractive index n₁ and normalized thickness ζ so that the ratio of complex reflection coefficients for the pand s polarizations of the film-covered substrate ρ is the inverse of that of the film-free substrate ρ¯ at a given angle of incidence φ. A pair of parallel (metallic) mirrors, one uncoated and the other coated with a ρ-inverting layer, causes a beam displacement without change of polarization and with a certain net reflectance (insertion loss) ℜ. In this …

Model Of Hot-Film Sensor With Substrate Effects, David Mcalpine Judge

Electrical & Computer Engineering Theses & Dissertations

A detailed mathematical model is constructed to investigate the frequency response of a hot-film anemometer system. Since several diverse factors affect the frequency response, the analysis is broken down into three main parts. Each part is a detailed mathematical model. The first model consists of the ordinary differential equations which govern the electronics of the feedback system and heat transfer of the sensor. An important simplification in this model is that the rate of heat conduction from the sensor to its substrate is constant.

In the second model the unsteady state heat transfer properties of the substrate are examined by …

Computered-Aided Digital Filter Design And Simulatio, Pao-Tsan Chiang

Theses

The simulation is written by C language on AT&T Unix pc 7300 environment, some fundamental mathematics is introduced in the beginning, then digital filter specification method: window, frequency sampling, equiripple are discussed, and Kaiser window method is discussed in details for programming.

There are many problems are met in my simulation, such as F.F.T. aliasing, leakage, Picket fence convolution, correlation, but solutions are proposed.

The result could be output data and graph, GSS_Drivers graph package is utilized, because consideration of operation speed and convenience are emphasized, speed is compromised, but easy to be restructured.

A Dsp Toolkit For The Unix/C Environment Of The Pc 7300 Compute, Suwutchai Jesdanun

Theses

The Digital Signal Processing (DSP) TOOLKIT is a package of programs designed to use the fast Fourier transform (FFT) and display its output responses in graphics form. This tool provides three different window functions and five data modifiers for filter designing and spectrum analysis. Flexible features for modifying the plottings, such as y-axis auto-scaling, xy-axis scaling and center line adjusting of the graphics display, are included.

All programs are written in C programming language for the UNIX System Environment of the UNIX PC 7300 computer. The program structure of DSP TOOLKIT is designed so that modules can be added or …

The Relationship Between Linguistic And Image Based Learning Approaches For Complex Problem Solving: A Case For Computer Generated Animation In Instructional Presentation Of Complex Technical Processes, Stanley T. Bissinger

Graduate Research Papers

The purpose of this study is to provide a rationale for development of new approaches to educating students about complex technical processes. This study may also prove helpful for determining what type of technical content is better suited for computer animated presentation.

An Investigation Of The Uses Of Scanning Electron Microscopy In The Analysis Of The Substructure Morphology Of Semiconducting Devices, Michael E. Courbat

Graduate Research Papers

The purpose of this study is to determine the technical requirements of SEM failure analysis in regard to its' inclusion in the Energy and Power curriculum of the Department of Industrial Technology, University of Northern Iowa.

The Influence Of Transverse Magnetic Fields On The Current-Voltage Characteristics Of Glow Discharges, Thomas J. Powers

Electrical & Computer Engineering Theses & Dissertations

In low pressure discharges, operated in electronegative gas mixtures to the right of the Paschen curve minimum, the discharge resistance can be increased by application of transverse magnetic fields. In this range of operation, both the mean free path and the larmor radius are small compared to the discharge dimensions. The relationship between the electric field and the magnetic field is therefore controlled by electron- molecule collisional processes. Specifically, the magnetically induced increase in the discharge resistance is caused by a downward shift of the electron energy distribution which leads to an increase in attachment and a reduction in ionization. …

Study Of Reliability And Failure Mechanism Of Solid Tantalum Capacitor, Rajan N. Bhatt

Theses

Today, reliability is acknowledged as an important item in design and operation of the electronic systems.

This thesis provides some theory, and experiments are instituted to evaluate the reliability of SOLID TANTALUM CAPACITORS made by reputed manufacturers. The experiment was conducted on four batches of tantalum capacitors at different temperatures at different humidity levels. One chapter is on different manufacturing techniques presently applied.

Literature study concentrates on the reliability in solid tantalum capacitors developed between 1961 and 1986.

Several failure mechanism with figure are illustrated to point out how higher reliability of solid tantalum capacitor may be developed.

The bibliography …

A Computer-Aided Design And Manufacturing System For Wiring Boards Production, Shiau Chia-Ming

Theses

Our purpose is to build some SBC-8052-BASIC microcontroller based instrument systems, and this thesis integrate resources from two areas into a powerful CAD/CAM system for this purpose. Since wiring board is the most popular used tool for laboratory development and small-scale manufacturing, a microcomputer-aided design and manufacturing system is developed to improve the whole efficiency from wirelisting and wiring sequences to hardware and software debugging. So anytime a circuit theory design stage is finished, the prototype can be made easily, then tested and redesigned, till last stage producing. Several practical wiring board circuits have been made through this system, it …

Microcomputer-Based Automated System To Monitor Flow And Respiratory Quotient, Chung C. Chien

Theses

An instrument system has been designed to monitor Respiratory Quotient experiments on rats which are living within whole-body calorimeters. By using multiplexing techniques, this system is capable of monitoring Respiratory Quotients in six calorimeters (animal chambers). It exhibits some features that make it more versatile than the previous system. One of the features of this instrument is that it uses a more accurate method of determining rapid changes in gas exchange between subject and environment. The value of this method is its ability to assess the rapid change in metabolic rate which occurs as a result of change in activity, …

A Data Compression System Using Arithmetic Code, Seokrim Choi

Theses

Generally it is difficult to compress data, from statistically unknown sources, with significant compression ratio. To achieve this, the compression scheme should have an ability to gather context information of the source, adaptively. For better compression, it is desirable to separate the context gathering scheme from coding itself. Arithmetic code is very flexible and can accept any kind of context gathering scheme which can generate probabilities. One context gathering algorithm which generates Markov type probability adaptively is studied and implemented in software using Arithmetic code. This scheme performs well and results in compression ratio better than any existing algorithms such …

Properties Of Sputtered A-Ge And A-Ge : H Thin Films, Hanjin Cho

Theses

The effect of the amorphous and glassy structure of amorphous germanium films on their electrical characteristics was investigated experimentally. The films were deposited onto silicon substrates using a modified MRC 8800 triode sputtering system. The Poole-Frenkel and Schottky mechanisms are discussed in detail and the shortcomings of the accepted picture of the former in amorphous materials are dealt with. It was concluded on the basis available evidence that the current flow in amorphous germanium favors the Poole-Frenkel mechanism at high fields.

Amorphous hydrogenated germanium films which were deposited by bias sputtering were characterized by measuring the infrared absorption. The films …

Image Analyzing Instrumentation System For The Activity Measurement Of Rats, Yun-Kang Li

Theses

A microcomputer based instrumentation system has been developed to measure the activity of rats in 12 metabolic chambers. The instrumentation system monitors the rats' behaviors and estimates their activity continuously in an automatic manner. The activity information of the rats are expressed by a quantitative index which describes the intensity of the activity level.

An Apple II microcomputer system is used to manage the activity measurement which consists of an image recording operation and an image analyzing operation. During the measurement, the microcomputer controls Optic RAM digital cameras to record the rats' image. The camera can take a digital picture …

Graphical Interpretation Of U.S. Tidal Data, Vaheh Shahbazian

Theses

Numerous Shore line operations relating to industry and conservation would benefit from convenient access to continuous tidal predictions. Easy Graphical access to continuous long term predictions of tidal heights at a location of interest will simplify operations that are sensetive to tidal predictions. A specific example, is the implementation of a protective measurements against flooding and destruction of shoreline facilities particularly at times of high tides.

This thesis consists of three things. First, rendering NOAA's data in a form accessable to a PC user. Second, it provides a Basic program for prediction of tides. Third , PC user programming Resourses …

Method Of Moments Analysis Of Very Thin Wires Using The Mini-Numerical Electromagnetics Code, Douglas F. Stolarz

Theses

The analysis of thin wire antenna systems in the presence of a conducting ground plane is an important engineering problem. This thesis presents an analysis of wire radiators using the method of moments as implemented in the Mini-Numerical Electromagnetics Code (MININEC). Due to singularities in the formulation, MININEC yields inaccurate results for very thin wires. This code was modified by introducing filament currents for very thin wire structures thereby eliminating inaccuracy due to the treatment of singularities.

The modified code was tested on a monopole over a perfect ground, symmetrical and asymmetrical dipoles in free space, and inverted L and …

Probabilistic Technique In Power Flow Analysis, Dun-Ren Tzeng

Theses

This thesis describes and examines a technique which permits the power flow problem in a power system to be analyzed probabilistically. Both the deterministic and the probabilistic power flow theories have been presented. A mathematical model and a program have been developed to carry out the probabilistic power flow calculation. Two power systems and seven different loading cases have been used to test the technique. The results including the sensitivity coefficient matrices, the expected line flows with their variances, and 25 of 176 probability density function curves, have been shown and discussed. An easy way to predict the possible abnormal …

A Cad Tool For Edif Model Generation, Sri Nagesh Valluri

Theses

This thesis describes a new CAD tool designed to create models proposed by Electronic Design Interchange Format steering committee. In its present form the system can generate models for standard SSI and MSI devices. The menu driven window based fillup the form features of the tool allows a novice user to provide structural and timing informations of the device from any manufacture's data book. The software performs online checking of the user data and guides them to generate the correct model.

Implementation Of Xilinx Development System And Xilinx Lca Application, Youcheng Wu

Theses

The Xilinx Application-Specific Integrated Circuit (ASIC) is a large array of programmable logic cells. Creating logic design using the Xilinx ASIC offers ease of implementation, high function density, design flexibility and lower consumption of supply power. The techniques of implementation of system and design with Xilinx CAD/CAM System include system analysis, modification, update, optimal design algorithms and real circuit emulation.

This thesis combines the setup and operation of the complete Xilinx system, and implement Xilinx LCA into 8052AH-BASIC based Single Board Computer and user's menu of real LCA chip evaluation Board. It presents our own design, construction, test and demonstration …

The Study Of The Response Of Nucleus Ambiguus Neurons To Blood Pressure Changes, Adrienne Zoe

Theses

The purpose of the project is to aid the study of the response of nucleus ambiguus neurons to changes in blood pressure. The sampling runs indicate that there is a correlation between blood pressure and neuron activity for some of the neurons monitored. Some neurons react to blood pressure increases by Increased neural firing rate while others react by decreased neural firing rate. Some neurons do not respond to blood pressure manipulation comprising the non-vagal neurons. A system was developed for the DIN PC to collect electrocardiogram, blood pressure, and neuron activity from a dog, and to perform non-real time …

Time Series Analysis Of Respiration Component In Heart Rate Variability, Anuradha Ramaswamy Iyengar

Theses

Time series signal processing techniques (Fourier based) were applied to analyze the relationship between heart rate and respiration. This analysis takes advantage of the different timing charecteristics of the autonomic nervous system inputs to analyze their influence on the heart rate.

Data from three experiments were analyzed. The first set of data was from helicopter pilots of the US Army. They injected atropine into themselves on certain days. The effect of atropine on the heart rate spectrum and the relationship between heart rate and respiration was studied. It was found that atropine abolishes the respiration peak in the heart rate …

Mizer : A Ruled Based Cad Tool For Logic Optimization, Sandip Mukerjee

Theses

This objective of this research was to develop a knowledge based CAD tool, to address the problems of Logic Design. MIZER is an expert system, that accepts functional specifications of a logic circuit and connectivity description of its implementation to generate an optimal design. This information is then used to develop a hazard free circuit that brings about an optimization in area and timing. It stores the newly created design into its knowledge base with the approval of the designer, for future use.

Analysis Of An Inertial Navigation System On A Silicon Wafer, Ashok K. Parida

Theses

This thesis describes a self-contained inertial navigation system for commercial vehicles. It is low cost miniature system employing some of the newest techniques in micromechanical and microelectronic hardware.

The system employes an array of vibrating tuning fork gyros, a number of feedback force-balance accelerometers, and a central processing unit, all fabricated on a silicon wafer using integrated circuit fabrication technology. A miniature platform (size of a golf ball) driven by gearless torque motors is used to provide a quiet environment for the gyros and accelerometers. There are radio links between components that are on and off the platform (eliminating need …

Digital Signal Processing Implementing The C Language With Graphics Spectrum Analysis Display, Anuraksa Mahanirananda

Theses

Digital Signal Processing discussed in this thesis is concerned with the transformation of signals or complex wave forms From time domain to frequency domain and vise-versa, implemented on microcomputer systems. The primary principles are: speed of transformation, ease of usage as an application program, capabilities of graphics displaying transformed data (such as power spectrum analysis), storing these data onto record files, and capability of using these data Files and programs with other application programs.

We begin by discussing briefly, the concepts of Fourier theory, Discrete and Fast Fourier Transform, algorithms of Fast Fourier Transform and bit-reversal. Then we implement these …

Comment On "Orientation, Alignment, And Hyperfine Effects On Dissociation Of Diatomic Molecules To Open Shell Atoms", Mark D. Havey, Linda L. Vahala

Electrical & Computer Engineering Faculty Publications

A recent paper in this journal [Y. B. Band e t a l., J. Chem. Phys. 8 4, 3762 (1986)] reported parameters describing orientation and alignment produced, in an axial recoil limit, by one photondissociation of diatomic molecules. Reported also were values, applicable to the resonance transitions of the alkali atoms, for orientation and alignment depolarization coefficients. Most of the numerical values reported for the coefficients were incorrect, in some cases by as much as a factor of 2. We report a tabulation of correct depolarization coefficients applicable to the resonance transitions of common alkali isotopes. Further, the coefficients …

Compiling Unit Clauses For The Warren Abstract Machine, George D. Herbert

UNF Graduate Theses and Dissertations

This thesis describes the design, development, and installation of a computer program which compiles unit clauses generated in a Prolog-based environment at Argonne National Laboratories into Warren Abstract Machine (WAM) code. The program enhances the capabilities of the environment by providing rapid unification and subsumption tests for the very significant class of unit clauses. This should improve performance substantially for large programs that generate and use many unit clauses.

Computer-Aided Testing Of Electrical Machines: Software Development, Max Darwin Anderson, Steven A. Hauk, Robert Laramore, Hardy J. Pottinger

Electrical and Computer Engineering Faculty Research & Creative Works

Computer-aided test stations have been developed for research, experimentation, and testing of electric motors and generators. Data acquisition and control of the machines and drives are provided through a computer and its interfaces. Machines are connected to the computer through transducers for data acquisition, and power electronic drives for machine control. General software was written to enable the monitoring of all transducers continuously on the CRT screen while giving the user manual control of the machines and drives. Specialized software was written for automatic control of the induction, dc, and synchronous machines for specific experiments on each type of machine. …

Thin-Film Beam Splitter That Reflects Light As A Half-Wave Retarder And Transmits It Without Change Of Polarization: Application To A Michelson Interferometer, R. M.A. Azzam

Electrical Engineering Faculty Publications

The refractive index n₁ of a transparent layer of quarter-wave optical thickness coating a transparent substrate of refractive index n₂ can be chosen to produce half-wave retardation (HWR) in reflection and no change of polarization in refraction at any angle of incidence ø. The function n₁(ø, n₂), and the associated polarization-independent reflectance of the film-substrate system R(ø, n₂) are determined. Such a coated surface can be used as a beam splitter with excellent characteristics (e.g., split fractions that do not depend on source polarization, a split beam whose polarization is identical …