Engineering Commons^™

Adaption And Optimization Of The Ibrahim Time Domain (Itd) Modal Parameter Identification Algorithm For Mini-Computer Use, Mary T. Cogeos

Retrospective Theses and Dissertations

Conventional modal analysis is performed using FFT Analyzers with modal analysis software developed by one of many test/analysis software vendors. The analysis is performed in the frequency domain using frequency response functions. A recent advancement in modal analysis involves analyzing the measured free response of a structure in the time domain. The Ibrahim Time Domain (ITD) Algorithm is such a method which has been used and verified at government environmental test facilities. The ITD is an accurate numeric solution. Minimal operator interaction is required for proper performance of the algorithm. The results of the ITD Algorithm are far superior to …

A Gate-Array Realization Of An Algorithm For Division, Salman Y. Abbasi

Retrospective Theses and Dissertations

A realization of a division algorithm suitable for high speed pipeline and realtime processors is presented. Implementation of the divide algorithm can be achieved by utilizing LSI / VLSI gate array technology. The divider performs precision, high speed 9 bit sign magnitude division. The design consist of combinational logic, where input and output data are latched into input and output registers. Data propagates through 16 divide stages. The n'th stage generates the n'th quotient bit upon receiving the updated dividend and controls from the previous stage. A simulation program is developed to verify the algorithm, and an analysis for speed …

Digital Image Processing Using Ntec Facilities, James F. Roesch

Retrospective Theses and Dissertations

Digital image enhancement refers to the improvement of a given image for human interpretation. Digital image processing facilities are those in which hardware and software computing elements are combined in such a way as to enable the processing of digital images. This report describes the use of the Naval Training Equipment Center (NTEC) Computer Systems Laboratory computing facilities to enhance digital images. Described are two major hardware systems, the IKONAS RDS-3000 raster display graphics system and the VAX-11/780, and the digital image processing program (DIMPRP) written by the author. Digital image enhancement theory and practice are addressed through a discussion …

State Space Approach To Flood Stage Estimation, Gregory Allen Jones

Dissertations and Theses

A flood routing and stage prediction model is developed using the techniques of State Space and Kalman filtering. The governing equation is the physically based hydrologic method of flood routing with the output being an optimal estimate of stage given known inputs of streamflow. These equations are developed in state space and the Kalman filter is employed to estimate the flow and river stage.

The model is applied to the Toutle and Cowlitz Rivers in the State of Washington, where the stage is affected by a shifting bed elevation. With the deterministic inputs at Mayfield Dam on the Cowlitz and …

A Numerical Solution For Three Dimensional Beam Columns In The Elastic Region, Hamid Reza Afghan

Dissertations and Theses

The three differential equations describing the behavior of the beam columns in three dimensions are derived and presented in finite difference form. A computer model is developed to solve the simultaneous equations in the elastic regions and predict the member behavior.

The computer program is checked by comparing the results obtained from the program with data from other investigators, and classical analytical techniques.

Highway Runoff And Sediment Control, Susanna H. Rehmann-Koo

Retrospective Theses and Dissertations

A literature survey was conducted on the erosion and sedimentation process and techniques for control. Erosion and sediment control techniques were found to be very site specific. Several techniques are analyzed for their maintenance and operation requirements, construction costs, and effectiveness in quantity and quality control. Once technique, namely swale blocks or berms was designed and constructed to illustrate cost and effectiveness. Design aids were developed for various berm heights and highway slopes as a function of berm spacing for typical highway cross-sections to aid in the design of swale blocks. Construction costs were estimated for the berms and retention/detention …

A Comparative Study Of Computer Interfacing Techniques For Military Training Devices, Gary R. Fraas

Retrospective Theses and Dissertations

This report surveys many of the interfacing techniques currently in use on emerging military training devices. The primary focus of this report is associated with the hardware aspects of computer interfacing. After a brief introduction into the various aspects of military training devices, this study presents various computer related interfacing techniques used on military training devices. Topics addressed in the study include custom designed interfaces, commercial packages, serial communications with an emphasis on RS-232, -422, -423, and -449 serial standards as well as local area networks. Then, a number of bus standards are presented and finally, interface products pertaining to …

Filter Settle Time For Signal Processing Applications, Michael T. Mccord

Retrospective Theses and Dissertations

In this paper, the step modulated sine wave [u(t)Asin2πft] response of the low-pass, band-pass, and high-pass filters are evaluated. Butterworth filters from the first order on up to the ideal filter are analyzed, and expressions for the settle times developed. The longest settle time occurs for the ideal filter, with all other filters taking progressively less time to settle as the order decreases. A significant point is that the transient settle time for a filter depends on the difference in applied signal frequency and the filter cut off frequency. The set of expressions developed in this report are primarily intended …

A Model For Scattering In Dense Clouds, Richard A. Leblanc

Retrospective Theses and Dissertations

Lights is almost always detected by its interaction with matter. One of these interaction phenomena is the scattering of light by small particles. A model is developed that estimates the amount of energy that is scattered towards a detector from a beam given the locations of the source, detector and particle. This collection of particles is allowed to be very dense so that a photon scattered from the beam can be scattered several times before leaving the scattering medium. By considering the single-scatter component and multiple-scatter component separately, the model retains the characteristics of both types.

A Robotic Vision System, Murat Draman

Retrospective Theses and Dissertations

A survey was done to summarize the state of the art and the future directions in the robotic vision field, in the industrial applications and research areas. An assembly language program, "GETIT", was written to control a MC6800 microprocessor in gathering data from an analog-to-digital converter hooked up to a camera, to find the center of a white marble placed on a black surface, and to send the coordinates to a five axis robot. A VAL language program, "VISION!", was written to receive the coordinate data from the microprocessor and to direct the robot to the specified location, to pick …

An Analytical Design Procedure For The Determination Of Effective Leading Edge Extensions On Thick Delta Wings, Farhad Ghaffari

Mechanical & Aerospace Engineering Theses & Dissertations

An analyt1cal des1gn procedure for Lead1ng-Edge Extensions (LEE) has been developed for thick delta wings. This LFE device is des1gned to be mounted to a w1ng along the pseudo-stagnation stream surface associated w1th the attached flow design lift coeff1cient of greater than zero. The intended purpose of the device is to improve the aerodynamic performance of high subsonic and low super son1c aircraft at incidences above that of attached flow design lift coefficient, by us1ng a vortex system emanating along the leading edges of the device. The low pressure assoc1ated with these vort1ces would act on the LEE upper surface …

Underwater Acoustic Wavefront Phase Fluctuations, George L. Vojtech Jr.

OES Theses and Dissertations

In conventional underwater acoustics sound propagation is generally modeled and applied as a coherent or incoherent process. This paper addresses a relatively new theory, that of a range driven increasingly incoherent ray propagation through a real ocean environment, Possible mechanisms are discussed and experimental data presented to reinforce the theory.

An Application Of Speech Synthesis, Edward J. Purvis

Retrospective Theses and Dissertations

This paper discusses the implementation of a synthesized computer voice facility for a missile trainer. The actual facility hardware is described. Software used to control the hardware operation is presented and discussed.

A Single Fault-Tolerant Dual Channel Controller, Thomas J. Lowery

Retrospective Theses and Dissertations

The advent of the VLSI technology makes it feasible to offer a once expensive system attribute called fault-tolerance to a wide variety of applications. This can be accomplished by using off-the-shelf single board computers and peripherals as the heart of the system. Custom design boards can then be added to meet the specific requirements of each application.

Graphic Display Of Geographic Spatial Data, Jill G. Ashby

Retrospective Theses and Dissertations

This project developed computer graphics to display spatial and statistical data in a functional, appropriate and articulate manner. The spatial data creates mapping of Orange County focusing on traffic zones. The graphs display statistical data projecting from spatial areas presented in a simple form. The graphs produced by the system are geared towards an audience involved with transportation and planning decisions for Orange County. The graphics employ population, income, number of dwelling units, trip generation and trip production data based upon the 1980 census. The population, income, and number of dwelling unites statistics include predictions for 1985 through 2005 in …

Finite Impulse Response Filter Implementation Via Windowing Technique, Thomas J. Horrigan

Retrospective Theses and Dissertations

This research report is devoted to an investigation of finite impulse response (FIR) filters and their implementation via windowing techniques. Analysis is restricted to those FIR filters that possess both a nonrecursive structure and a linear phase response. Initially an informative yet concise overview of FIR filters is presented. Some knowledge of "discrete – time" systems is assumed. Next, the concepts associated with FIR filter implementation through the utilization of window functions is developed. Analysis is performed in both the time and frequency domains. Results obtained define optimal window function criteria. The last design technique is devoted to computer aided …

A Study On Fragmentation And Ground Vibration With Air Space In The Blasthole, Everett Ellsworth Bleakney Iii

Masters Theses

"The degree of fragmentation and the level of ground vibration from a bench blast employing standard full-column completely-coupled explosive charges are commonly controlled by varying one or more of the many dimensional variables of blast design. Blasting techniques such as decoupling and air-gapping, utilizing air space in the blasthole, have also been reported as having the potential to control rock fragmentation and ground vibration.

This investigation, using reduced-scale in situ bench blasts, examined the degree of fragmentation and the level of ground vibrations produced from the standard full-column completely-coupled, air-gapped, and decoupled methods of blasting to:

1. Compare the effectiveness …

A Thermal Contact Conductance Correlation For Mechanically Expanded Finned Tube Heat Exchangers, Mahmoud Ahmed Abu Ebid

Masters Theses

"Tests were conducted in dry vacuum environment, on eight mechanically expanded finned tube heat exchangers (with 3/8 inch outer diameter tubes) with different geometries including variation in fin thickness, fin collar length, and net interference. One of the eight heat exchangers was also tested under wet conditions. A mathematical model was used to calculate the thermal contact conductance from the experimental data. An error analysis was performed to estimate the range of error in determining the thermal contact conductance. A correlation of the dry contact conductance in terms of fin number (actual fin collar length in contact with the tubes), …

Preparation And Properties Of Phosphorus Oxynitride Glasses, Mary R. Reidmeyer

Masters Theses

"The preparation techniques and properties of phosphorus oxynitride glasses produced from sodium metaphosphate and nitride compounds are reported. A preliminary survey of possible nitride additives to sodium metaphosphate is presented along with an extended study of the two most promising nitrides, AIN and Mg₃N₂. Properties reported include: nitrogen content, dissolution rate in water, thermal expansion coefficient, softening point, glass transformation temperature, density, refractive index, microhardness, and infrared absorption"--Abstract, page 1.

The Compositional And Temperature Dependence Of Radiation-Induced Void Nucleation And Swelling In Austenitic Alloys, Bahram Esmailzadeh

Masters Theses

"The objective of this study is to introduce a model which can demonstrate the major features of the compositional and temperature dependence of radiation-induced swelling of austenitic alloys. The effective vacancy diffusion coefficient, D_V^eff, is the prime variable explored in this study. Variations in D_V^eff with composition and/or irradiation temperature are used along with the KWR nucleation theory to determine the subsequent effects of these variables on the void nucleation rate and the duration of the transient regime. The materials chosen for this study are nickel (Ni) and the Ni-Si, Fe-Ni-Cr and Fe-Ni-Cr-Si alloy systems. …

An Investigation Of Methods Of Surface Estimation With Application To The Interpolation Of Antenna Patterns, Paul Matthew Niall Feehan

Masters Theses

"The problem of estimating a surface from a set of discrete measurements lying along straight lines is considered. This situation arises when one attempts to determine the S-Band antenna gain pattern for the Space Shuttle, from measurements taken at several ground stations. The results of previous investigators concerned with the performance of surface approximation techniques for the present application, are extended in this study by examining the case where the data samples are corrupted by measurement noise. Results have been obtained using least-squares approximation with bicubic B-spline basis functions, and for an interpolation algorithm in conjunction with a spatial smoothing …

Solid Solubility Of Sulfur In Transition Metal Oxides And Stability Of Sulfates Relevant To Roasting Processes, Zeynal Karakus

Masters Theses

"Two types of sulfur equilibration experiments were carried out in this study using either a conventional thermal gravimetric analysis (TGA) technique or a horizontal tube furnace apparatus. Samples were equilibrated with flowing SO₂-O₂ gas mixtures of either 58% SO₂ or 10% SO₂.

The types of experiments were:
1. Investigation of the extent of solid solution of sulfur in ZnO, NiO, CuO, and Fe₂O₃ over a wide range of temperature.
2. Studies of compound or solid solution formation between binary sulfate mixtures of Fe-Zn, Cu-Zn, Ni-Zn, Fe-Cr, and Cd-Zn by TGA.

The …

Structural Behavior Of Cold-Formed Steel Beam Webs Subjected To Partial Edge Loading, Shin-Hua Lin

Masters Theses

"An extensive experimental investigation has been conducted to study the load-carrying capacity of cold-formed steel web elements subjected to partial edge loading which may cause web crippling or web buckling. In this experimental work emphasis was concentrated on the cold-formed steel structural members having single unreinforced webs with stiffened flanges.

In 1980, American Iron and Steel Institute (AISI) revised its "Specification for the Design of Cold-Formed Steel Structural Members.” For the design of beam webs, Section 3.5.1 of the AISI Specification provides the design criteria for web crippling. This thesis discusses the experimental work including some specimens with small length-to-depth …

Ion Implantation For Improvement Of Wear Properties Of Steels, Kenneth W. Burris

Masters Theses

"Previous research on ion implantation at U.M.R. has dealt with the development of a modified Falex Lubricant Tester as a valid wear test and its use in dose curve determination. Our recent work uses Auger surface analysis and scanning electron microscopy to gather support for a model that will tie together some of the many theories proposed as to why ion-implantation improves the surface related mechanical properties of steels"--Abstract, page ii.

The Role Of Multinational Corporations In The Transfer Of Management Technology To Nigeria, Liwhu Undiandeye

Dissertations and Theses @ UNI

The development of an active and viable managerial cadre in the developing nations is necessary for the initiation and sustainment of industrial growth and productivity. Management is not only able to recognize profitable opportunities but also possess sufficient entrepreneurial skills that can be organized for technological growth. Managerial skills are abundantly present in the West and significantly lacking in the developing nations. One of the ways to stimulate industrial growth in the developing nations is to transfer these abundant skills from the West. The transferability of western management technology to non-western cultures has been characterized by uncertainty as regards its …

The Modeling And Control Of Freeze Dryers, Martin James Millman

Doctoral Dissertations

"Two models of the freeze drying process were constructed and used to study various operational policies in order to determine the policy that would provide the shortest drying times.

The sublimation model which accounts only for the removal of frozen water, is found to predict shorter times for the free water removal phase than the sorption-sublimation model which properly accounts for the removal of frozen and bound water.

This study shows that the policy which produces the shortest free water removal phase, also produces the shortest overall drying time. This policy, predicted by both models, holds the chamber pressure at …

Unsteady-State Cylindrical, Spherical And Linear Flow In Porous Media, Allan Jeffrey Anthony Joseph

Doctoral Dissertations

"The general problem of unsteady flow phenomena in porous media as considered in this investigation. Emphasis was placed upon the short-term flow characteristics within cylindrical, spherical and linear reservoir geometries, and practical analysis methods were developed for each problem. Additionally, nonlinear unsteady flow behavior in infinite reservoirs was considered. Each solution obtained could optionally be implemented by hand or computer, and several FORTRAN subprograms were also presented.

At present, the only way to analyze pressure transient data prior to the development of the "semi log straight line" is by type curve matching techniques. However, this study indicated that a reliable …

Thermogravimetric And Electrical Conductivity Studies Of Mg-Doped Lacro₃ And La-Doped Srtio₃, Brian Keith Flandermeyer

Doctoral Dissertations

"Mg-doped LaCrO₃ and La-doped SrTiO₃ are perovskite compounds that display electrical conductivity which is a function of partial pressure of oxygen (po2). It has been proposed that acceptor-doped LaCrO₃ becomes highly resistive at low po2's due to ionic compensation of the acceptor-dopant present by oxygen vacancies. SrTiO₃ has been thought to absorb O₂ into a crystallographic shear structure and exsolve strontium vacancies which can then ionically compensate the La present and give a high resistance at high po2's.

Given these models, relationships between weight loss and conductivity vs. po₂ are developed for both these …

Applications Of Finite And Wave Envelope Element Approximations To Acoustic Radiation From Turbofan Engine Inlets In Flight, A. V. Parrett

Doctoral Dissertations

"The problem of acoustic radiation from turbofan engine inlets in flow has not lent itself fully to analysis by numerical means because of the large domains and high frequencies involved. This project has extended the use of finite elements and wave envelope elements, elements which simulate decay and wavelike behaviour in their interpolation functions, from the no-flow case in which they have been proven, to cases incorporating mean flow. By employing an irrotational mean flow assumption, the acoustics problem has been posed in an axisymmetric formulation in terms of acoustic velocity potential, thus minimising computer solution storage requirements. The wave …

Fixed Bed Sorption With Recycle, John Thomas Casey

Doctoral Dissertations

"A mathematical model that describes single and multicomponent recycle-sorption systems is constructed. The model accounts for the generation of species by chemical reactions occurring in a single perfectly mixed tank, in the bulk fluid of the sorbent bed, and in the pores of the adsorbent particles.

Results are shown for single zeroth, first and second order reversible reactions as well as a network consisting of two first or second order reactions which may occur in series or parallel. For systems in which a single reaction occurs, both linear and non-linear equilibrium adsorption isotherms are considered. If multiple reactions occur, then …