Engineering Commons^™

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 …

A Theory Of Lexical Semantics, William C. Purdy

Electrical Engineering and Computer Science - All Scholarship

The linguistic theory of Richard Montague (variously referred to as Montague Grammar or Montague Semantics) provides a comprehensive formalized account of natural language semantics. It appears to be particularly applicable to the problem of natural language understanding by computer systems. However the theory does not deal with meaning at the lexical level. With few exceptions, lexical items are treated simply as unanalyzed basic expressions. As a result, comparison of distinct lexical meanings or of semantic expressions containing these lexical meanings falls outside the theory. In this paper, I attempt to provide a compatible compatible theory of lexical semantics which may …

Moment Method Analysis Of The Electric Field Under Ehv Transmission Lines, T. L. Simpson, Charles W. Brice

Faculty Publications

The charge moment method is applied to the analysis of electric fields under EHV transmission lines over irregular terrain.

Decision-Directed Multivariate Empirical Bayes Classification With Nonstationary Priors, Wynn C. Stirling, A. Lee Swindlehurst

Faculty Publications

A decision-directed learning strategy is presented to recursively estimate (i.e., track) the time-varying a priori distribution for a multivariate empirical Bayes adaptive classification rule. The problem is formulated by modeling the prior distribution as a finite-state vector Markov chain and using past decisions to estimate the time evolution of the state of this chain. The solution is obtained by implementing an exact recursive nonlinear estimator for the rate vector of a multivariate discrete-time point process representing the decisions. This estimator obtains the Doob decomposition of the decision process with respect to the a-field generated by all past decisions and corresponds …

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 …

Characteristics Of Heteroepitaxial Si-Bp Structures Grown At A Single Growth Temperature, Perry J. Robertson

All Dissertations

No abstract provided.

Photodetector Arrangement For Measuring The State Of Polarization Of, Rasheed M.A. Azzam

University of New Orleans Patents

A photopolarimeter for the simultaneous measurement of all four Stokes parameters of light. The light beam, the state of polarization of which is to be determined, strikes, at oblique angles of incidence, three photodetector surfaces in succession, each of which is partially specularly reflecting and each of which generates an electrical signal proportional to the fraction of the radiation it absorbs. A fourth photodetector is substantially totally light absorbtive and detects the remainder of the light. The four outputs thus developed form a 4x1 signal vector I which is linearly related, I=A S, to the input Stokes vector S. Consequently, …

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.

Angular Sensitivity Of Brewster-Angle Reflection Polarizers: An Analytical Treatment, R. M.A. Azzam

Electrical Engineering Faculty Publications

The angular sensitivity of Brewster-angle reflection polarizers (BARP) is first studied approximately by determining the Taylor series expansion of the parallel reflectance R_p as a function of angle of incidence ø near the Brewster angle ø_B. Subsequently, exact and explicit equations are derived that determine the lower and upper limits, ø_l and ø_u, of the range of ø, that includes ø_B, over which R_p or the extinction ratioER is below a stated limit L. Examples are given of Ge and Si IR BARP for which ø_l and ø …

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. …

Power Division By Element Design In A Circularly Polarized, Series-Fed Array, James L. Drewniak, P. E. Mayes

Electrical and Computer Engineering Faculty Research & Creative Works

The feasibility of designing a wideband circular polarized (CP) array of series-fed elements using the element geometry to control the array excitation has been demonstrated. The simple array of wideband, low-profile CP elements requires no phase-shifters and only sufficient feed lines for the interconnection of the elements in a series-fed array. A complicated network is not required to obtain the excitation coefficients for a specified design. Rather, the excitation coefficients can be realized by utilizing the geometric parameters of the individual elements.

A Dual Circular Polarization Radiating-Line Antenna, James L. Drewniak, P. E. Mayes, D. Tanner, J. Woodruff

Electrical and Computer Engineering Faculty Research & Creative Works

No abstract provided.

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 …

Ksc2408 Digital Filter Evaluation System For The Ecg, Chi-Tong Chung

Theses

A hardware implementation in digital filters by using the high speed and high precision KSC2408 digital filter chips, demonstrates the power of the KSC2408 and proves that the real time digital filters can be implemented without complex circuitry and without high expense.

The system consists of two parts - the digital filter board and the IBM PC; the former handles the data filtering, the latter handles the analog-to-digital data conversion and data display. The KSC2408 is programmed as a 16th order Butterworth digital filter to have flat response in the passband and good attenuation in the stopband.

Reliability Evaluation Of Liquid Crystal Displays Under Accelerated Life Conditions, Rajkumar Krishnamoorthy

Theses

This Thesis shows method of comparing the reliability of Liquid Crystal Display Devices by means of accelerated life testing at elevated temperature and relative humidity for two different vendors.

The tests were carried out at three different combinations of temperature and humidity.

1. 77°±1° C and no added humidity.

2. 85°±1° C and no added humidity

3. 98°±1° C and 98+2% relative humidity.

Leakage current measurements were carried out after every 1000 hours for up to 5000 hours for vendor no.l. Measurements were carried at 0, 500, 1000, 2000, 3000 and 5000 hours for vendor no.2. A DC bias of …

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 …

Investigation Of The Size Of Gallium Clusters Formed Using A Modified Ion Cluster Beam Source With A Crucible Temperature Of 1250 Degrees C, Sujit M. Shah

Theses

Energy analysis of the ionized gallium clusters was done by retarding field method. The objective of this research was to investigate the possibility of gallium cluster formation during nozzle jet expansion and to estimate the probability of ionization of clusters. The measurements at a crucible temperature of 1250°C corresponding to gallium vapor pressure of 0.23 torr (inside the crucible) showed that no large cluster sizes could be obtained. The relationship between mass deposition rate (atoms/cm2-sec) and cluster size (atoms/cluster) showed that there were two distinct peaks. One with a cluster size of 1 atom/cluster and the other with about 13 …

Reliability Studies On Microcircuit, Salim Shehadeh

Theses

The primary objective of this thesis is to determine and analyze the failure mechanisms of Low Power Schottky microcircuit device (2-Input NAND Gate). Pinpoint the causes, and suggest the precautionary measures that prevent the occurrence of these failures. To achieve this goal, the study went in two directions, theoretical and experimental. The theoretical part is a comprehensive review of the work done on Low Power Schottky 2-Input NAND Gates since 1960 up to date.

The experimental part of the study is a life test ( 1000 hours ) of 2-Input NAND Gates under humidity and high temperature.

For each unit, …

Life Testing Of Solid Dielectric Materials, Muhammad Irfan Soomro

Theses

The main objective of this thesis was to find correlation between the electrical noise generated within the body of the solid dielectric material with the failure (puncture), under simultaneously applied thermal and electrical stresses.

The term 'Corona' is commonly used to describe any partial discharges occurring in voids (defects) in the material. Precisely corona is a flow of electrons and ions which occur in a void in air or other gasses. This event emits acoustic, optical and radio frequency energy, and can be detected by measuring any of these radiations. In the present thesis, Radio Interference Voltage (RIV) technique was …

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.

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 …

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 …

Xilinx Asic Design For A Single Board Computer, Hong Zhan Ye

Theses

Xilinx Application-Specific IC is a new kind of programmable cell array with high design flexibility and functional density. It not only has excellent circuit-board utilization and low power consumption, but it also offers easy implementation with lower engineering cost and very short production-rampup period.

This thesis provides a complete and specific procedure for implementing Xilinx LCA into a 8052AH-BASIC based single board computer with XACT development system. It verifies all the results from debugging SBC2064 design using both XACT query system and P-SILOS simulator.

The technology of implementing a whole system design with software and hardware fully proves the possibility …

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 …

An Investigation Of Electrical And Optical Properties Of Sputtered Amorphous Silicon Nitride And Germanium Thin Films, Rajendra S. Khandelwal

Theses

Low temperature preparation of thin amorphous Silicon Nitride and Germanium Films by direct RF sputter deposition was investigated. Influence of various sputtering parameters on film properties was studied. Infrared transmission spectrophotometry was used to evaluate optical properties of the films whereas electrical characteristics of the films were determined from current-voltage measurements of MIS structures. For Silicon Nitride films it was observed that the stoichiometry, as indicated by the IR transmission, dielectric constant and current density versus square root of electric field measurements, was a strong function of the sputtering gas composition and particularly the Ar/N ratio in the sputtering gas. …