Engineering Commons^™

Adaptive Discrete Cosine Transform Image Compression Applied To Visual Flight Simulators, Nancy A. Burrell

Retrospective Theses and Dissertations

A visual flight simulator requires a huge amount of image data to be stored in the database. To make a photo-based system feasible an image compression scheme must be devised to compress the data.

An adaptive discrete cosine transform (DCT) technique is used to compress 24 bit color images to an average of 3 bits per pixel. The bits for the image are distributed based on the relative activity in different parts of the scene. Results and error analysis are presented.

The Use Of Enlarged Feed Wells As Flocculator Units In Activated Sludge Secondary Clarifiers, Mahnaz Shahnami

Retrospective Theses and Dissertations

The quality of the effluent from activated sludge wastewater treatment plants is highly dependent on the performance of the final clarifier. The final clarifier performs solids/liquids separation through sedimentation. The standard design criteria (overflow rate and detention time) must be selected such that the effluent suspended solids requirements are met.

Numerous research programs have been conducted to evaluate the factors affecting the sedimentation efficiency of activated sludge mixed liquor. Flocculation has been documented as a significant factor. The flocculation process is an agglomeration of small primary particles of the surface of larger particles to achieve higher settling velocities. Increased settling …

Fate Of Phosphorus From Residential Stormwater Runoff In A Southern Hardwood Wetland, Benjamin M. Fries

Retrospective Theses and Dissertations

The movement and fate of phosphorous inputs from residential stormwater runoff were investigated in a 1.0 hectare hardwood wetland near Sanford, Florida. This wetland receives stormwater runoff from a large residential community through a small shallow canal and provides treatment prior to discharge to Hidden Lake. Field investigations were begun in 1984 and were divided into the following tasks: (1) assessment of the quantity of nutrients and heavy metals entering the wetland by way of stormwater runoff, (2) measurement of the attenuation (3) monitoring of the concentrations of nutrients and heavy metals in groundwaters, (4) accumulation of nutrients and heavy …

Numerical Simulation Of Air-Conditioning Heat Recovery Water Heating Systems, Amir H. Gorji

Retrospective Theses and Dissertations

A computer simulation program called TRNSYS (Transient System Simulation) was used to model two air-conditioning waste heat recovery water heating configurations. The first model is a heat recovery unit (HRU) that utilizes an 80-gallon storage tank in conjunction with a conventional home air-conditioning system. The second model is similar to the first, except that there is an additional 80-gallon preheat storage tank. An attempt was made to compare simulation results with experimental field data. However, due to problems encountered during the field tests, such as equipment and/or instrumentation failure, there were not enough experimental data to make a rigorous comparison. …

Multiplexing Phototransistor Arrays Using Transistor Capacitance, Gary E. Morrissette

Retrospective Theses and Dissertations

Photodetector Focal Plane Arrays are used in electronic image detection. This paper examines the multiplexer that converts the detected signals to a Time Division Multiplexed form. This paper will present two types of multiplexers, a traditional linear multiplexer and a matrix addressed multiplexer. These arrays will use the concept of charge storage to amplify the detected signal. The capacitance of the junctions of phototransistors are used for charge storage.

Apodization Of Surface Acoustic Wave Three Phase Unidirectional Transducers, Benjamin P. Abbott

Retrospective Theses and Dissertations

This thesis presents an introduction to surface acoustic wave (SAW unidirectional transducer (UDT) apodization. An unbalanced apodization structure is described. The structure is shown to suffer from an unbalanced capacitive effects, significant apodization losses and passband ripple. A balanced UDT structure is developed for the purpose of improving performance and minimizing undesirable effects associated with the unbalanced structure.

Each apodization structure is analyzed and compared using a typical impulse response of a SAW transducer. The analysis is accomplished using SAWCAD2, a unidirectional Surface Acoustic Wave Computer Aided Design FORTRAN-77 program developed at the University of Central Florida. Having shown the …

The Design And Implementation Of Surface Acoustic Wave Devices For Linear Fm And Nonlinear Fm Pulse Compression Technique For Radar Applications, James C. Walker

Retrospective Theses and Dissertations

The purpose of this work is to design, fabricate, and compare dispersive SAW devices using both linear FM and a new non-linear FM scheme. This new non-linear FM scheme uses the Blackman function as the modulating signal of the FM waveform. Up-chirped and V-chirped devices for both linear and the new non-linear FM scheme and their corresponding matched filters are compared.

Design considerations are discussed in detail. An efficient sampling algorithm (which can also be applied to other non-linearly modulated FM waveforms) developed to facilitate the design of the SAW devices is presented.

A Signal Conditioner For Speech Processing, Daniel K. Weir

Retrospective Theses and Dissertations

This thesis describes the design, implementation and testing of an analog signal conditioner for use in processing of speech signals. The signal conditioner provides gain and bandwidth control for the speech signal and also indicates the signal level. It is designed to be used in conjunction with a digital speech processor and has ports for a microphone or other signal source, an input signal monitoring device such as an oscilloscope, and interfaces to the digital speech processor. Signal bandwidth control is provided by a variable cutoff frequency lowpass switched capacitor filter, which is driven by a clock. In this thesis, …

Simulating The Thermal Behavior An Earth-Stationed Satellite Terminal, Anthony M. Jacobi

Retrospective Theses and Dissertations

Lumped parameter modeling using finite differencing, form the basis for a C language simulation of a thermal system. The study of the earth-stationed satellite terminal includes an introduction to the system, derivation of the governing equation, development of a simulation, and a comparison of the results to empirical data.

The analysis is undertaken with emphasis on the worst-case thermal environment, and with determination of the cooling loads and transient response as primary goals. Comparing the predicted cooling loads to empirical data, and previous analyses, indicates an accurate simulation has been constructed. The computer models are offered as an alternative method …

Editor Design In The Context Of Control System Simulation, Leon Fadden

Retrospective Theses and Dissertations

Advances in microcomputer display devices and support software during the past decade have made the microcomputer an increasingly popular vehicle for technical education. This is especially apparent in the area of simulation. The pedagog can provide the student of control theory not merely with the block diagrams and differential algebra but with high resolution color graphic animations supported by mathematical models whose parameters are easily changed by some editor facility. This mode of control system design and behavior study is both faster and more enjoyable for the student, providing greater continuity, concentration, and learning efficiency.

This paper describes the simulation …

Transient Critical Heat Flux, Kemal O. Pasamehmetoglu

Retrospective Theses and Dissertations

The term Critical Heat Flux (CHF) is used in boiling heat transfer to describe the local value of the heat flux at which a characteristic reduction in heat transfer coefficient first occurs. In today’s technology, the CHF is a phenomenon related to the design and safety of various important devices.

A major limitation on the thermal design of a light-water reactor (LWR) is the necessity to maintain an adequate safety margin between the CHF and the local heat flux. Extended operations at local power levels in excess of the CHF can lead to high temperature oxidation and embrittlement or melting …

The Integration Of Computer Graphics With Video Disc Technology: An Application In Training, Fereidon Torkzadeh

Retrospective Theses and Dissertations

The major objective of the work outlined in this paper is to become familiar with the MOVIE.BYU graphic system from Brigham Young University to demonstrate its use in the generation of non real-time images for a typical pilot training application. The implementation is done by using the MOVIE.BYU graphics system, a VAX 11/750 digital computer, and RAMTEK 9460 system. This paper discusses how the images can be stored a frame at a time on a video disc for playback at the normal rate to portray a moving scene using a Panasonic video disc recorder and player, and a Sony video …

Graphics Package For Portable Alphanumerical/Graphics Terminal, Elsie S. Loh

Retrospective Theses and Dissertations

This research report describes the design of a highlevel graphics package for use by application programmers t o display pictures of two-dimensional objects on a portable alphanumeric/graphic terminal. The design is implemented on the Digital VAX-11/780™ minicomputer running under the VMS operating system environment as the host computer and uses the DECwriter Correspondent (LA12) as the graphics device. The graphics package consists both the database manipulation software which is completely device dependent, and the interface software between the normal "drawing functions" and the hardware associated with a particular graphics device, which is minimally device-dependent.

Separation Plane Priority In Computer Image Generation, Keith A. Stump

Retrospective Theses and Dissertations

Flight simulators are devices in which air crews can be trained without the use of actual aircraft. Potentially dangerous maneuvers, such as air-to-air refueling, and destructive exercises, such as evasive action from weaponry or aerial dogfights, can be practiced repeatedly with no risk to pilot or crew. Flight simulators are cost effective since the fuel costs associated with training pilots in actual aircraft can be excessive. Flight simulators offer an alternate training method with reduced cost. The task of a visual flight simulator is to present the trainee with scenes representative of those that would be seen if the actual …

Interactive Texturing For A Computer Graphics Display System, Yin L. Wah

Retrospective Theses and Dissertations

Surfaces have texture, and few surfaces are truly smooth in the real world, yet this is how they are modeled. Texturing provides the illusion of increased surface roughness or granularity, and it also gives the illusion of extra detail and realism. This is accomplished by modulating surface color based on gradient function known as texture pattern.

Changing texture pattern data can be expensive and time consuming since the change must be done on database offline system and then reloaded on the Computer Image Generator (CIG) for review of the change. The Interactive Generator (IAT) system is designed for online examination …

Setting Time Standards In A Service Environment: A Case Study, Nael H. Hasweh

Retrospective Theses and Dissertations

One of the most important and costliest resources a hospital has are its personnel and their productivity. Almost invariably, they offer the greatest opportunities for cost containment.

This report is the result of a study conducted in the maintenance department at a local hospital. The objective of the study was to design and implement a work measurement system that is capable of producing accurate time standards. Comparison of actual times reported by employees with these standards would then be used to produce accurate productivity measures.

The proposed system is explained in detail, and the results obtained by implementing such a …

Interactive Micro-Computer Software For The Production Of Engineering Drawings, Brian R. Garvey

Retrospective Theses and Dissertations

This project has developed a microcomputer-based interactive Graphics Software System for the production of engineering drawings. The drawings, stored in a digital format, can be recalled and updated much faster than by using conventional drawing methods. This allows for increased production and a standardized drawing format.

The system was designed to be easy to use so that with little training, a user can create, edit, plot, and save drawings for later retrieval. In addition, an open architecture was used in the design of the drawing database and program command structure so that the system can be easily expanded upon as …

Feasibility Investigation Into The Use Of A Liquid Crystal Television As A Spatial Light Modulator, Edward R. Raudenbush

Retrospective Theses and Dissertations

The recent availability of inexpensive, electrically addressable liquid crystal displays has generated interest in the use of such devices for optical processing applications. Characterizations pertinent to this use include: maximum obtainable modulation depth, modulation transfer function (MTF), linearity of response, refresh cycle time and optical flatness. Examples of device performance as a coherent processor and as an incoherent processor will be given.

Non-Linear Plane Stress Analysis Using The Finite Element Method, Habib Amirzadeh

Retrospective Theses and Dissertations

Purpose of the Study

The objective of this report is to check the Neuber and Linear rules, and to find the percent differences in comparison with the plane stress and plane strain solution using the non-linear finite element method. All the data are based on the maximum stress concentration where the crack forms and the material behaves non-linearly. This particular problem has been solved using ANSYS, which is a general purpose finite element program.

Life Prediction

Another purpose, which is not the main subject of this report, is to use the result from Neuber and Linear rules to predict the …

Corrosion Ability And The Chemistry Of Mercuric Chloride And Related Compounds, Martin R. Kruger

Retrospective Theses and Dissertations

This research project found that a solution of methanol and methylene chloride saturated with mercuric chloride was very effective at diffusing through a paint film and destroying an aluminum barrier below. The project also found evidence that mercuric chloride chemically reacts with dimethylformamide and dimethysulfoxide. The project concluded that corrosion of metals in an organic solvent media is best studied by thermal analysis.

A Theoretical Evaluation Of Water Surface Changes In A Circular Reservoir, Hossein G. Tehrani

Retrospective Theses and Dissertations

The purpose of this project is primarily to develop an equation to estimate the time that it will take for the water surface to decrease to another depth in an inverted conical-shaped reservoir behind an earth dam by means of the falling head permeability concept. This equation can be applied to the earth embankment either with or without underdrain. Since the derived equation for time span is a complicated and tedious matter, a computer program has been developed for solving this equation.

The computer program is written in BASIC language and executed on a Tektronix 4051 microcomputer. Primary effort has …

The Effect Of Detention Period On The Clarification Efficiency Of Nitrified Activated Sludge, James C. Boyd

Retrospective Theses and Dissertations

Proper performance of the final clarifier in the activated sludge process is vital to total system efficiency. Inadequate clarification can adversely affect substrate removal efficiency due to the biochemical oxygen demand exerted by solids lost in the clarifier effluent. Detention period is one factor which influences clarification performance and thus is of interest to the designer engineer. Also of interest is the relationship between detention period and rising sludge conditions in the clarifier, which can lead to a deterioration in clarification efficiency. Rising Sludge conditions are believed to be caused by the denitrification of nitrified activated sludge in the final …

Distribution Of Lead And Zinc In Groundwater Around An Exfiltration Pipe Including A Study Of Specific Conductance, Donna M. Schiffer

Retrospective Theses and Dissertations

Highway runoff is a significant source of nonpoint pollution to surfoce and ground waters. Underground disposal of stormwater has several advantages, such as recharge of ground water resources and reduction of flow rates at existing storm sewer outfa11s. However, there are few studies on the effects of underground disposal of stormwater on the qua1ity of ground water. The purpose of this stucty was to examine the changes 1n lead, zinc, and specific conductance in highway runoff that is routed to an underground disposal facility as the water passes through the unsaturated soil to the surficia1 aquifer. An exfiltration pipe in …

The Application Of Expert Systems To Automated Storage And Retrieval, Robert E. Mcdonald

Retrospective Theses and Dissertations

This report discusses the major functions, decisions, and strategies of automated storage and retrieval systems (AR/RS). The report surveys the essential features of expert systems and discusses how they can be applied in automated warehousing environments. A blackboard expert system architecture was examined and found to be a flexible and responsive control system for automated warehousing applications. A simple AR/RS expert system was constructed using an expert system software package. A warehousing simulation was performed which compared the expert system’s performance to a typical AR/RS control system. The expert system produced increased efficiency of operation because of the intelligent rules …

Design Considerations In The Development Of An Automated Cartographic System, Robert L. Holden

Retrospective Theses and Dissertations

Cartography, the art of producing maps, is an extremely tedious job which is prone to human error and requires many hours for the completion of maps and their digital data bases. Cartography is a classic example of a job that needs to be automated. Through the new advances in image processing and pattern recognition, the automation of this task is made possible with the cartographer acting as a supervisor. This paper reviews current cartographic techniques, and examines design considerations for a fully automated cartographic system. The benefits of such a system would be improvements in speed, flexibility, and accuracy. The …

A Computer Simulation Of An Incoherent Optical Processor For Spatial Frequency Analysis, Randall T. Stratton

Retrospective Theses and Dissertations

A computer simulation demonstrates the feasibility of a technique for performing spatial frequency analysis on an incoherent scene in one dimension using an electronically addressable spatial light modulator (SLM). By applying biased sinusoidal variation to the SLM transmittance, the real and imaginary parts of the Fourier transform are available and readily yield both magnitude and phase of the Fourier transform.

In addition to the Fourier transform this simulation investigates the use of a simple binary pulse train transform for the sake of reducing system complexity and increasing speed of operation.

Noise In Interferometric Sensors, Mark Phillips

Retrospective Theses and Dissertations

A noise analysis is conducted on an interferometric sensor employed in the study of underwater acoustic noise. Primary emphasis is placed on finding the output Signal to Noise Ratio of the sensor.

Once the initial problem of the type of noise is established, the analysis proceeds along fairly classical lines. Field equations establish the signal reaching the director. Linear filter analysis establishes the nature of the spectrum after passing through a lowpass filter. Finally, second moment theory is used to derive expressions for the output Signal to Noise Ratio.

It is noted that the random ocean noise introduced to the …

The Effect Of Thickness On Neuber's Rule For Estimation Of Fatigue Life, Shahram Elmi

Retrospective Theses and Dissertations

To predict the fatigue life of a notched member from a strain-life curve, the high strain concentration at the root of the notch must be known. For determining this high (post yield) strain, the Neuber’s Rule (for plane stress) and linear rule (for plane strain) can be applied. To investigate the accuracy of these method a notched member which is subjected to fully reversed cyclic loading is analyzed by the finite element method. Moreover, members with different thicknesses are analyzed with three dimensional elements, and a correlation between plane and three dimensional data is obtained. This correlation may be used …

Direct Sequence Spread Spectrum Acquisition Design, John C. Fakatselis

Retrospective Theses and Dissertations

Spread spectrum communication techniques are utilized to provide transmission of signals which have anti-jamming properties, a low probability of being intercepted, and can support a multiple-access system by servicing simultaneously a number of channels. This thesis concentrates on the receiver acquisition problem of a transmitted signal which is the output of a spread spectrum communication system. The acquisition requirements of a spread spectrum system and also the general approaches to the problem of “active and passive correlation” are discussed. A unique general purpose all-digital acquisition hardware design is developed and described to the schematic level of detail, where specific parts …

A Zero Extraction And Separation Technique For Surface Acoustic Wave And Digital Signal Processing Fir Filter Implementation, Keith V. Lindsay

Retrospective Theses and Dissertations

Presented is a new method of separating the zeros of a Finite Impulse Response (FIR) filter producing optimal digital filter of surface acoustic wave (SAW) design implementation. Overviews of zero extraction algorithms and of FIR filter design using the Remez Exchange algorithm are presented (McClellen et al. 1973).

The computer aided design (CAD) procedure presented allows the designer to specify the general filter characteristic which the Remez algorithm translates to FIR time domain coefficients. These coefficients are readily translated to the frequency (z) domain, producing an Nth order polynomial in z. The characteristic polynomial is factored to determine all roots …