Digital Commons Network^™

Decentralized Optimal Control With Application To Dynamic Routing In Computer Communication Networks, Ning Wang

Dissertations

This research considers the dynamic routing problem of computer communication networks in the framework of decentralized control theory. The routing dynamics are modeled in terms of a state equation with multiple controllers. Routing, or control of message flow, is formulated as an optimal control problem with multiple decision makers. Each decision maker may have access to different set of information and work cooperatively to optimize a common system performance index.

Necessary and sufficient conditions for optimality are derived for a system with a deterministic and a stochastic traffic patterns under a linear information structure and a quadratic performance index. The …

An Experimental Study Of Temperature Separation In Swirling Flow, Hiromoto Kuroda

Doctoral Dissertations

The objective of the present investigation is to substantiate the mechanism of acoustic streaming; this was carried out by conducting detailed internal surveys of a Ranque-Hilsch swirling flow test rig at the condition when the vortex whistle was attenuated or excited. This control of the vortex whistle was accomplished by two methods.

In the first method where the vortex whistle was attenuated by placing a restriction at the exhaust, a Rankine vortex was observed to form, accompanied by an almost uniform total temperature distribution in the radial direction except for a dip near the vortex core; when the vortex whistle …

Solar Air Heaters For On-Farm Crop Drying: Case Studies, Alvin Ray Womac

Masters Theses

Three types of suspended plate solar air heaters were installed on farms in Tennessee to supply heat for grain and crop drying. A wrap-around solar air heater was constructed on a row crop farm in West Tennessee and used to dry 210 m³ (6000 bu) of corn during Fall 1982 and 105 m³ (3000 bu) of wheat during Spring 1983. Three portable solar air heaters were installed on a row crop farm in Middle Tennessee and used to dry 800 m³ (23000 bu) of soybeans and 120 m³ (3500 bu) of corn during Fall 1982. A …

Two-Dimensional Computer Modeling Of Joints And Fractures In Continua, Royd R. Nelson

Theses and Dissertations

This thesis presents a numerical formulation which incorporates the effects of joints, cracks, and fractures into a mathematical mode used to in an existing finite element code. Two separate crack definitions were incorporated, one involving a discrete crack model, and the other a continuum approach defining a new material with regularly spaced joints. Several examples are also presented demonstrating the use of this capability.

Stochastic Estimation Applied To The Land Speed Of Sound Record Attempt By A Rocket Car, David A. Reinholz

Theses and Dissertations

Optimal linear smoothing theory is applied to the data from the Speed of Sound record attempt of a three-wheeled rocket car on 17 December 1979. A forward-backward estimation method is used which employs a seven state forward-running extended Kalman filter and a Meditch-form backward recursive 'fixed-interval' smoothing algorithm. Data for this analysis is supplied by a longitudinal accelerometer mounted on the vehicle and tracking radar measurements of range, azimuth, and elevation. States of interest include two components of vehicle position and velocity, accelerometer time-correlated error, and radar range and azimuth bias errors. Two iterations of the forward-backward smoothing algorithm provide …

Effect Of Refrigerant Charge And Condenser Temperature On The Operating Characteristics Of A Vapor-Compression Air Conditioning System, Ezzat Fikri Assaad

Archived Theses and Dissertations

No abstract provided.

Mathematical Models Of Unsteady Operation Of A Packed Column, Jen-Fu Chao

Dissertations

Analytical solutions of differential equations applicable to extraction, ion exchange, or adsorption processes in packed beds are presented. Results are given for three different cases. The first case accounts for adsorption phenomena only. The second one includes surface adsorption on particles and the effects of longitudinal dispersion in the bed. The third one deals with diffusion in particles and longitudinal dispersion in the bed. In the mathematical modelling of these three cases, a linear equilibrium relationship between the solute in the liquid phase and solute in the solid phase is used. The first case is solved using the single boundary …

The Settling Of An Arbitrary Number Of Spherical Particles Arranged On The Corners Of A Regular Polygon In A Viscous Fluid, Eric Robert Bixon

Dissertations

The creeping motion equation has been solved for the case of planar arrays of spheres settling under the influence of gravity in a viscous fluid. The solution is a general solution which applies to an arbitrary number of spheres. All particles will lie at the corners of a regular polygon. Thus, two particles side by side, three particles in an equilateral triangular array, or four spheres in a square array will be special cases of the general solution.

The solution has been obtained by a unique application of the method of reflections. Only a first correction to the drag has …

The Fundamental Hardware Elements And Options Of Digital Signal Processing, Mark A. Hemmerlein

Retrospective Theses and Dissertations

The hardware available for digital signal processing is evaluated. The elements required for implementation of digital signal processing applications are identified. These elements--memories, ALUs and multipliers -- are analyzed. Then the operation of parts which make up a range of possible solutions are evaluated. Thus, the graduating engineer is aided in making a transition from the theoretical to the practical world.

On The Theory And Experimental Results Of A Sensitive Fiber Optic Laser Accelerometer, Steven C. Furlong

Retrospective Theses and Dissertations

No abstract provided.

Application Of Ground Penetrating Radar To The Detection Of Subsurface Cavities, Gary L. Kuhns

Retrospective Theses and Dissertations

Ground Penetrating Radar (GPR) identifies subsurface features by distinguishing materials with different dielectric constants and electrical conductivities. Subsurface cavities can, therefore, be detected by the variation in their electrical properties from the electrical properties of the surrounding material. To test the cavity detection ability of GPR, subsurface cavities of varying size, shape and content were modeled. Radar response to the cavity models was found to be affected by the composition of the surrounding soil material, the depth of the groundwater table, and the radar signal frequency. Based on knowledge gained from the cavity modeling study, a natural subsurface cavity was …

Testing Of Active Feedback Applied To Piezoelectric Devices, William H. Barrow

Retrospective Theses and Dissertations

The purpose of this research is to test a unique implementation of active feedback applied to a low frequency piezoelectric transducer. Understanding that active feedback can be used to shape the frequency response of an electrical system a method for applying active electroacoustical feedback will be used to obtain a wider acoustical bandwidth in a piezoelectric transmitter. By applying active feedback to a resonant device its bandwidth was increased by a factor of 2.5. This is a significant improvement for applications where minimum electrical phase shift versus frequency is desired.

Digital Filtering With The Iapx 86/20, Robert E. Canright

Retrospective Theses and Dissertations

The iAPX 86/20 (8086 with the 8087 numeric coprocessor) is considered for digital filtering. The advantage in using the iAPX 86/20 lies in the 80-bit width of the 8087 floating-point arithmetic-registers. With such large arithmetic registers, the effects of coefficient roundoff and arithmetic roundoff errors on the filter output are reduced. The price paid for the improved numerical performance is the increased time spent by the system moving data to and from memory. The method of Knowles and Olcayto for measuring the effect of coefficient roundoff is studies in detail. This method is applied to an example filter in order …

Models For Economic Evaluation Of Flexible Manufacturing Systems, Daniel P. Salomon

Retrospective Theses and Dissertations

The current methods of economic justification are not suitable for identifying the benefits of automated manufacturing systems. This study is an introduction to Flexible Manufacturing Systems (FMS), its main features, and the economic benefits that can be expected. The models are designed to perform the following analyses: 1. Analysis of direct cost savings. 2. Analysis of the impact of incremental implementation on capital recovery costs. 3. Analysis of the cost effects of improving machine utilization and reducing manufacturing lead time. 4. Sensitivity analysis of the after-tax equivalent uniform annual cost of a FMS and a conventional system. The models are …

Design Of A Single User Deconcentrator For A Conferenced Voice Communication Circuit Switching System, Ming-Yung Wen

Retrospective Theses and Dissertations

A single user deconcentrator is designed for a circuit switched digital switching system which emphasizes mass conferencing. The switching system consists of distributed concentrators which include a first level of conferencing and a broadcast bus which includes a second level of conferencing. The deconcentrator features volume adjustment of individual conferences as well as a third and last level of conferencing- a conference of the individual conferences obtained from the broadcast bus. The design identifies the MSI and SSI components of the deconcentrator and provides an estimate of timing and board size. An alternative volume adjustment algorithm and the extension of …

Design Of Efficient Algorithms Through Minimization Of Data Transfers, Yong Mo Chong

Electrical & Computer Engineering Theses & Dissertations

This thesis explores the time optimal implementation of computational graphs on a finite register machine. The implementation fully exploits the machine architecture, especially, the number of registers. The derived algorithms allow one to obtain time efficient implementations of a given graph in machines with a known number of registers.

These optimization procedures are applied to digital signal processing graphs. It is shown that the regular structure of these graphs allows one to identify computational kernels which, when used repeatedly, can cover the entire graph. The l- and r-register implementations of Hadamard and Fast Fourier Transforms using various computational kernels are …

Kinetics Of Biodegradation Of Phenol And 2,6-Dichlorophenol, Samir Shrikant Desai

Theses

Biological removal of phenol up to 600 ppm and 2,6-dichlorophenol up to 20 ppm was studied in a well aerated fill-and-draw reactor of 41 capacity at 26 C using an activated sludge obtained from the municipal treatment plant in Livingston, N.J. Experimental evaluation of kinetic parameters showed that biodegradation of both phenol and 2,6-DCP followed zero-order kinetics. As expected, the lag time for both compounds was considerably reduced when acclimated sludge was used. However, the metabolism of 2,6-DCP was very slow even for preacclimated sludge, requiring about 36 hours to degrade only 15 ppm.. This was markedly improved by the …

The Lewis-Matheson Method On Computer, William Raymond Castner

Theses

Lewis and Matheson, in the early 1930's, developed a manual calculation technique for the solution of multicomponent distillation problems. The object of this study was to see if there would be any advantage to using the Lewis-Matheson method, once incorporated onto a computer, over current multicomponent distillation solution techniques. The immediate advantage of using the L-M technique is that it requires fewer preliminary calculations than other computer methods. It was found that the L-M technique uses about half the execution time of a typical Newton-Raphson program, while using only one tenth the computer core (memory). This was not intended to …

Mathematical Model Of Temperature Profiles And Coking In A Crude Oil Heater Tube, Joseph C. Polimeni

Theses

A mathematical model to predict temperature profiles and coking of crude oil in furnace tubes is presented. The model assumes that the coking mechanism is due to a reaction in the laminar sublayer, whose rate depends upon the temperature profile. That profile is obtained by a numerical solution of the appropriate transport equations, with velocity profiles that may be laminar or turbulent, and including the temperature dependence of the crude oil properties. In addition, velocity and temperature profiles were adjusted when necessary to ensure closure of the heat and material balances. As a by-product of this study, a correction was …

A Machining System For Turning Nonaxisymmetric Surfaces, Spivey Stevens Douglass

Doctoral Dissertations

Aspheric reflecting surfaces possessing extremely high surface finish and contour accuracy are often demanded by the optics industry. Such reflectors have also been required in high energy gas laser systems used to trigger thermonuclear reactions in experiments connected with advanced electric power generation.

Historically, production of optical pieces of the quality described required many repetitions of selective hand-lapping, polishing and measuring. In the past ten years production of these pieces has been enhanced by machining with diamond cutting tools on precision numerically controlled (NC) turning machines. These machines are capable of generating axisymmetric surfaces competitive in quality to those produced …

Development Of A Computer-Aided Graphics Capability To Display Field Test Data, L. Allen Adams

Theses and Dissertations

This thesis develops an interactive computer-aided graphics package for the display of experimental and field test data. EXPERT was developed to be used in conjunction with MOVIE.BYU and DISSPLA, utilizing a bivariate interpolation scheme to create a full field of data using the "sparse" field data as pivotal points. The usefulness and practicality of the program is demonstrated by graphically displaying the data from the Air Force Weapons Laboratory's CHEAT test.

Feasibility Of Graywater Systems For The Florida Environment, Joseph L. Tessitore

Retrospective Theses and Dissertations

The objectives of this report was to study the existing literature and data of residential graywater treatment and disposal systems and their possible applications and environmental impacts in Florida. The report addresses mainly (1) the definition of graywater quantity and quality, (2) the evaluation of proposed graywater treatment systems for possible reuse and disposal, (3) the impact of residential graywater systems on existing and proposed wastewater treatment plants, and (4) the possible impacts on groundwater and surface water environment. The report also presents some preliminary residential graywater treatment and disposal system designs including expected treatment efficiencies and cost. It should …

The Use Of Computer Vision To Close The Control Loop Of A Robot Arm, Randall S. Janka

Retrospective Theses and Dissertations

Flexible automation is a partial solution to America's industrial and economic recovery and survivability. At the core of this manufacturing technology is the robot whose own flexibility is enhanced through the use of computer vision to close the control loop on the arm and also give the robot environmental intelligence. The basic subdivisions of a computer vision system are sensing, segmentation, description, recognition, and interpretation. When the vision processor analyzes a scene it can give the robot controller symbolic object information and object coordinates. The robot controller transforms such coordinates into its own reference frame through the use of homogeneous …

Three-Phase Unidirectional Surface Acoustic Wave Transducer Model And Computer Aided Design Implementation, Samuel M. Richie

Retrospective Theses and Dissertations

This thesis presents an introduction into surface acoustics wave (SAW) unidirectional transducer (UDT) technologies and identifies advantages and disadvantages of various approaches. A complete model of the three-phase unidirectional structure is presented for the purpose of design analysis. This model incorporates the effects of the electrodes and transducer pattern along with the equivalent circuit model of the transducer structure. The model, when included with the appropriate peripheral components for transducer phasing and matching, can be used to determine accurately the frequency response of a given transducer structure. Such a model is well suited for implementation on a digital computer. With …

Considerations Involved In Implementing Material Requirements Planning In A Government Contractor Firm, Susan B. Biberman

Retrospective Theses and Dissertations

The government often imposes requirements on their contractors for the purpose of monitoring and control. Many government contractors utilize a matrix organization structure to help cope with the government's ever changing and challenging requirements. It is both the government requirements and this matrix organization which lead to the need for special information and features in a government contractor's manufacturing/material control system. This report specifically addresses those features which would be desirable in a government contractor's MRP system. These features involve the operation of the master schedule, the bill of material, the MRP software, the inventory files, purchasing, and shop floor …

Analysis Of Scheduling For Low Cost Part Task Trainers, William Fellows

Retrospective Theses and Dissertations

This study develops a methodology for the analysis of Part Task Trainer (PTT) refresh scheduling used in conjunction with large simulators. A human performance model is defined through the development of descriptive equations and system random variables. PTT scheduling calculations are performed by employing a computer program simulation. The computer algorithm generates a set of random vectors to represent the learning characteristics of a sample group of individual trainees. The relationships between simulator scheduling time, PTT frequency training, and model variables are demonstrated to be user interactive. This will allow the PTT refresh scheduling program to be used as an …

Pressure Drop Across A Tube Support Plate Of Trefoil Geometry Used In Steam Generator, Raad H. Bashar

Retrospective Theses and Dissertations

This research is concerned with the presentation of pressure drop experimental results across a restriction of trefoil geometry (tube support plate) used in steam generators. The pressure drops were obtained for single-phase and two-phase of air, water, and their mixtures. The tests were performed at atmospheric conditions (pressure and temperature). The loss coefficients associated with these pressure drops were experimentally determined, and empirical correlations for the results were developed. The results were compared with previous studies done on other geometries with air-water mixtures, and also to a similar geometry with steam-water mixture.

A Mini Apple Network For Apple Ii Plus Computers, Michael E. Harnage

Retrospective Theses and Dissertations

Computer networks have become increasingly popular over the last ten years. A simple low cost Mini Apple Network that uses Apple II plus computers and Apple's Parallel Interface Cards, is presented here. The Mini Apple Network is driven by PIC DRIVER, a software program that is able to transmit an Applesoft array variable from one computer to another. Three application programs are presented. A comparison is made of the gain in execution time when one, two, and three computers are used to solve the same problem, namely Laplace's partial differential equation. An increase in gain was obtained when the number …

The Design Of A Deep Ocean Hydrophone, Michael F. Hackathorn

Retrospective Theses and Dissertations

A design for a deep ocean hydrophone is proposed here. The hydrophone's sound sensing element is comprised of a capped end, piezoelectric cylinder. This sound sensing element is encased in an acoustic coupling fluid filled elastomeric boot. A small diameter tube communicates hydrostatic pressure from the coupling fluid to the interior of the sound sensing element for hydrostatic pressure compensation. The theoretical free field voltage sensitivity, the ratio of open circuit voltage to incident acoustic pressure, is predicted from mathematical model of the sound sensing element.

The Use Of Companding In Conferencing Voice Communications Systems, Jon P. Klages

Retrospective Theses and Dissertations

Compounded codes are used for representing voice data in digital communication systems. This thesis addresses the use of the Mu-law companding algorithm in a system optimized for conferencing. A procedure for determining the degree of compression for a variable number of conferees and design equations for implementing a table-lookup scheme using read-only-memories are presented.