Engineering Commons^™

Real-Time Communication In The Algorithm To Architecture Mapping Model, Somesh M. Varma

Electrical & Computer Engineering Theses & Dissertations

The objective of this thesis is to analyze schedules of communication resources to obtain deterministic and contention-free communication in the Algorithm To Architecture Mapping Model (ATAMM). In ATAMM, performance must be deterministic to guarantee meeting deadlines. It is difficult to achieve deterministic performance in the presence of contention during communication. This thesis develops new data-flow models to study and analyze different schedules of communication resources to achieve deterministic and contention-free communication. These models are the Synchronous Communication Marked Graph (SCMG) and the Asynchronous Communication Marked Graph (ACMG). The SCMG is based on message passing synchronous communication. It defines schedules for …

Navigation Satellite Selection Using Neural Networks, Daniel J. Simon, Hossny El-Sherief

Electrical and Computer Engineering Faculty Publications

The application of neural networks to optimal satellite subset selection for navigation use is discussed. The methods presented in this paper are general enough to be applicable regardless of how many satellite signals are being processed by the receiver. The optimal satellite subset is chosen by minimizing a quantity known as Geometric Dilution of Precision (GDOP), which is given by the trace of the inverse of the measurement matrix. An artificial neural network learns the functional relationships between the entries of a measurement matrix and the eigenvalues of its inverse, and thus generates GDOP without inverting a matrix. Simulation results …

On Primitive Bch Codes With Unequal Error Protection Capabilities, Robert H. Morelos-Zaragoza, Shu Lin

Faculty Publications

Presents a class of binary primitive BCH codes that have unequal-error-protection (UEP) capabilities. The authors use a previous result on the span of their minimum weight vectors to show that binary primitive BCH codes, containing second-order punctured Reed-Muller (RM) codes of the same minimum distance, are binary-cyclic UEP codes. The values of the error correction levels for this class of binary LUEP codes are estimated.

A Robust Method Of Solving Nonlinear Boundary Value Problems Via Modified Compromise Programming, John L. Zornick

Theses and Dissertations

This study is an extension of Ng's previous work in which goal programming was used to determine an approximate solution to a boundary value problem. This approach follows the same basic approach developed by Ng in which the method of collocation was recast as a compromise programming model. Hence, instead of solving a system of simultaneous nonlinear equations, one seeks a compromise solution which minimizes (in a weighted residual sense) a vector norm of the differential equation residuals. A difference in this approach is that it makes use of a genetic algorithm as the optimizing engine as opposed to the …

An Adaptive "Natural Law" Fuzzy Controller, Sandeep D. Sequeira

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Fuzzy control has met with a tremendous interest in applications over the past few years. Despite its application potential, a broader industrial exploitation of fuzzy control has been hindered by the lack of standard design methods for fuzzy control systems. Fuzzy controllers have had to be designed on a case-by-case basis employing heuristics and reflecting the designer's limited insight into the control object's behavior. A number of fuzzy theorists have investigated the fuzzy system theoretic problems and results reported in the literature have been encouraging.

This thesis research has explored the notion that fuzzy control, despite being a rule-based control …

Techniques To Improve Electron Density Measurements In The D Region Of The Ionosphere, Earl F. Pound

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The electron density of the ionosphere can be measured using rocket-borne probes that measure changes of the impedance of an antenna as it traverses the plasma. The resistive component of the antenna impedance is difficult to measure accurately in the D region of the ionosphere (50-90 km) because it has such a small value and is in series with a much larger capacitive reactance. The resistance term is squared during data analysis and this further adds to the inaccuracy. Previous data analysis has usually ignored the resistive term and led to errors of as much as 35% for the altitude …

Spatial Variability And Error Limits Of Reference Evapotranspiration Estimates, Thomas W. Ley

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The overall objective of this research was to develop a methodology for assessing the spatial variability and error limits of reference evapotranspiration (ET_r) estimates from a weather station network. Likely errors introduced into ET_r estimates due to sensor measurement variability and nonstandard site conditions were investigated. Temporal and spatial correlation structures of the weather variables used to compute ET_r and of ET_r data collected over a three-year period by an operational agricultural weather station network were studied.

Results indicated that ET_r errors are minimal compared to inherent model error when sensors (of the type …

Impact Of Alternative Refrigerants On Evaporator Design And Analysis Of Compact Heat Exchangers, Dadeech Parag

Masters Theses and Doctoral Dissertations

This thesis deals with the evaluation of the impact of alternate refrigerants on the thermal design parameters of different heat exchangers, such as, plate fin and tube, shell and tube evaporator and compact heat exchangers. A computer code has been developed in Quick-Basic language to conduct this investigation.

Determination Of Alas Optical Constants By Variable Angle Spectroscopic Ellipsometry And A Multisample Analysis, C. M. Herzinger, H. Yao, Paul G. Snyder, F. G. Celii, Y. C. Kao, B. Johs, John A. Woollam

Department of Electrical and Computer Engineering: Faculty Publications

Using variable angle spectroscopic ellipsometry, optical constants for AlAs (1.4-5.0 eV) are presented which are simultaneously compatible with measured data from four different samples. The below-gap index values are compatible with published prism measured values. The second derivative spectrum are compatible with published values above the direct band gap. The AlAs spectra is Kramers-Kronig self-consistent over the measured range and is compatible with published values from 0.6 to 1.4 eV. The optical constants for thin (<50 >Å) GaAs caps on AlAs are shown to be different from bulk GaAs values and require special consideration when fitting ellipsometric data. For the …

Development Of A Safety Management System, Kenneth R. Agent, Jerry G. Pigman

Kentucky Transportation Center Research Report

The Safety Management System (SMS) is one of six management systems mandated by Section 1 034 of the 1991 lntermodal Surface Transportation Efficiency Act (ISTEA). The overall goal of a SMS is to reduce the number and severity of traffic crashes. lt is to be comprehensive in that it incorporates all public roads and all contributing factors associated with the driver, the vehicle, and the roadway. The objective of this study was to develop a procedure to implement a SMS for Kentucky. A recommended process is described. Agencies and organizations were identified which have a role or interest in traffic …

Development Of An Alternate Methodology For Identifying Heavy/Coal Trucks And Calculating Esal’S/Axle And Axles/Truck, Jack A. Harison, David L. Allen, Jerry G. Pigman

Kentucky Transportation Center Research Report

No abstract provided.

Equivalent Single Axleload Computer Program Enhancements, Jerry G. Pigman, David L. Allen, Jack A. Harison, Neil Tollner, David H. Cain

Kentucky Transportation Center Research Report

The objectives of the study were to review and modify previously used Equivalent Single Axleload (ESAL) prediction procedures and to develop a more efficient procedure. As part of the effort to simplify the procedure, a subtask was undertaken to reduce the number of highway functional classes being used to process data for the ESAL estimation procedure. Another objective was to develop a more definitive and accurate method for reflecting the effects of coal or heavy truck movements. Results of this task were documented as Research Report KTC-95-6.

Analyses were performed and validated to reduce the twelve functional classes to six …

Performance Of Pyrament Cement Concrete In A Highway Bridge Deck, David Q. Hunsucker, Michael D. Stone

Kentucky Transportation Center Research Report

Pyrament Blended Cement (PBC) is a high performance cement that was developed by Lone Star Industries. Concrete that is made with PBC is rapid setting, has high strength and low permeability. The Kentucky Transportation Cabinet chose to use PBC concrete in a lull·depth bridge deck. The objectives of this study were to evaluate the construction and performance of a full-depth bridge deck constructed of PBC concrete and to compare the data obtained to historical construction and performance properties of conventional, Class AA bridge deck concrete. This report provides information relative to construction activities, materials properties, and a summary of the …

Performance Of Shrinkage Compensating Bridge Deck Concrete (Class S) I-75, Kenton County, David Q. Hunsucker, Michael D. Stone

Kentucky Transportation Center Research Report

Shrinkage Compensating Concrete (Class S) is made with an expansive cement in which the expansion, if restrained, induces compressive stresses that approximately offset tensile stresses induced during drying shrinkage, thereby eliminating or significantly reducing the occurrence of shrinkage cracking in concrete. The objectives of this study were to evaluate the construction and performance of the Shrinkage Compensating Concrete (Class S) and to compare these characteristics to previous Class S concrete data and to conventional Class AA bridge deck concrete. This report summarizes construction activities and provides final performance evaluations and recommendations relative to experimental decks and barrier walls constructed of …

Bs News

Building Services Engineering

No abstract provided.

Behavior Of Cold-Formed Steel Roof Trusses, Michael M. Harper, Roger A. Laboube, Wei-Wen Yu

CCFSS Library (1939 - present)

PREFACE To aid in adapting cold-formed steel to the residential market, a research project was initiated in 1993 at the University of Missouri-Rolla. Design issues relating to the use of cold-formed steel members and connections in residential roof truss systems were the focus of the project. The purpose of this research was to study the behavior of cold-formed steel roof truss systems and to establish appropriate design recommendations. Overall, the research findings were intended to aid the promotion of cold-formed steel as a safe, serviceable, and cost effective alternative in residential construction. The project consisted of a review of available …

Thermalhydraulics Analysis Of The Unit-Cell Nuclear Light Bulb Rocket Engine, Vojislav Banjac

Nuclear Engineering ETDs

This dissertation presents a detailed thermalhydraulics analysis of the unit-cell derivative of the Nuclear Light Bulb (NLB) rocket engine. The NLB engine is a gas core nuclear rocket first proposed in the 1960's by the then-United Aircraft Research Laboratories (UARL); its unit-cell derivative consists of a low-temperature moderator/reflector as well as segmented propellant channels, both proposed with the intent of increasing the k_eff of the system.

The results of this work can be grouped into two major areas: (1) thermal and neutronics analysis of the engine, and (2) investigation of the feasibility of the engine over a wide range …

Visualization Of Flow Around Bluff Bodies, Khaled Mohamed Elsherbini

Archived Theses and Dissertations

No abstract provided.

Development Of A Bid/No Bid Decision Index For Construction Contractors, Zeyad Hamed-Ramzy Hakam

Archived Theses and Dissertations

No abstract provided.

Identification And Evaluation Of Monitoring Techniques For The Performance Of A Communication Network, Maureen E. Borgia

Theses and Dissertations

This study investigates the application of statistical process control methods to monitoring the performance of a communication network. The methods applied include four different types of control charts. The literature search uncovered only one previous study that used a control chart to monitor a communication network. Using a case study of a communication network, four important issues for proper control chart usage are emphasized. These issues are: proper data collection rate due to autocorrelation, proper subgrouping of the data, ensuring that count data conforms to the assumptions of the binomial probability model before implementing p or np control charts, and …

Nonparametric Stochastic Generation Of Daily Precipitation And Other Weather Variables, Rajagopalan Balaji

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Traditional stochastic approaches for synthetic generation of weather variables often assume a prior functional form for the stochastic process, are often not capable of reproducing the probabilistic structure present in the data, and may not be uniformly applicable across sites. In an attempt to find a general framework for stochastic generation of weather variables, this study marks a unique departure from the traditional approaches, and ushers in the use of data-driven nonparametric techniques and demonstrates their utility.

Precipitation is one of the key variables that drive hydrologic systems and hence warrants more focus. In this regard, two major aspects of …

Evaluation Of Synthetic Unit Hydrograph Techniques For Utah Probable Maximum Flood Determinations, Ashraf Mohammed Shammet

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Every dam must be capable of safely passing a predetermined flood magnitude. For high-hazard dams, it is a common practice to require that this flood be the Probable Maximum Flood (PMF). The determination of the PMF starts with the determination of the Probable Maximum Precipitation (PMP). We used the generalized estimates of the PMP as outlined in Hydrometeorological Report (HMR) 49. In this study we used the storm event model approach to convert the PMP into PMF. Different synthetic unit hydrograph (SUH) techniques were then used in the conversion process. The Soil Conservation Service (SCS) curve number method was used …

Improved Finite Analytic Methods For Solving Advection-Dominated Transport Equation In Highly Variable Velocity Field, Wei Cuifeng

Dissertations and Theses

Solute transport studies frequently rely on numerical solutions of the classical advection-diffusion equation. Unfortunately, solutions obtained with traditional finite difference and finite element techniques typically exhibit excessive numerical diffusion or spurious oscillation when advection dominates, especially when velocity field is highly variable.

One recently developed technique, the finite analytic method, offers an attractive alternative. Finite analytic methods utilize local analytic solutions in discrete elements to obtain the algebraic representations of the governing partial differential equations, thus eliminating the truncation error in the finite difference and the use of approximating functions in the finite element method. The finite analytic solutions have …

Tractor Test Museum Committee Minutes April 21, 1995, Tractor Museum

Lester F. Larsen Tractor Museum: Planning and Development Documents

Hitchcock Foundation Potential Committee Member Tree Removal

Improving Operational Readiness Of Airport Emergency Response Crews: Utilization Of Gaming Theory In Decision Making Simulations, William E. Vines Jr.

Master's Theses - Daytona Beach

The purpose of this study was to evaluate the potential effects of simulation gaming technique on the decision-making skills of airport emergency response technicians. Through the use of descriptive research methods this study has examined the benefits of using simulation training to enhance operational readiness. A specialized questionnaire was developed using a Likert scale format to attain the opinion of 20 airport directors--or their representatives. Findings did support the research hypothesis that the introduction of simulation training (Table Top) exercises would increase the operational readiness of airport emergency response crews. Statistical analysis of survey responses found that no significant difference …

Application Of Macro Material Flow Modeling To The Decision Making Process For Integrated Waste Management Systems, Samuel A. Vigil, Gregory M. Holter

Civil and Environmental Engineering

Computer models have been used for almost a decade to model and analyze various aspects of solid waste management. Commercially available models exist for estimating the capital and operating costs of landfills, waste-to-energy facilities and compost systems and for optimizing system performance along a single dimension (e.g. cost or transportation distance).

An alternative to the use of currently available models is the more flexible macro material flow modeling approach in which a macro scale or regional level approach is taken. Waste materials are tracked through the complete integrated waste management cycle from generation through recycling and reuse, and finally to …

Visible Light Emitting Diodes Fabricated From Soluble Semiconducting Polymers, Alan J. Heeger, David Braun

Electrical Engineering

Visible light LEDs are produced having a layer of conjugated polymer which is cast directly from solution or formed as a gel-processed admixture with a carrier polymer. The LEDs can be formed so as to emit polarized light.

Assessment Of Infiltration Practices In The Florida Energy Code, Florida Solar Energy Center, James Cummings

FSEC Energy Research Center®

The Florida Department of Community Affairs has contracted with the Florida Solar Energy Center (FSEC) to review the current infiltration practices of the Florida Energy Code to determine, based on analysis of the best currently available infiltration data, whether there is need for three infiltration practices, and to make recommendations of what "point multipliers" should be applied to the infiltration practice(s). An advisory committee of industry, utility, and research representatives was formed to review the findings of the project and express opinions about the form the infiltration practices should take. This committee met twice, reviewed each of the reports produced …

Effects Of Varying Coupling Impedance, Finite Length, And Asynchronous Harmonics On High Power Bwo Performance, Larald Dean Moreland

Electrical and Computer Engineering ETDs

A systematic study of high power backward wave oscillators (BWOs) was performed using the Sinus-6 repetitively-pulsed relativistic electron beam accelerator. Peak output power of up to 550 MW was measured in a frequency range of 9.2 to 9.8 GHz with pulse lengths up to 10 ns. The experimental results were compared with numerical simulations using TWOQUICK, a 2.5 D, relativistic, fully electromagnetic, particle-in-cell (PIC) code. It was observed that a significant increase in microwave efficiency can be obtained by using a BWO with a spatially varying coupling impedance instead of the traditional uniform distribution. Based on experiments using variations of …

Comparison Of Rapid Prototyping Systems For Implementation Into The Product Development Cycle, Daniel S. Koenig

Graduate Research Papers

The problems with the implementation and use of RP technology is choosing the best system from the fifteen or more RP systems commercially available and more than 20 other systems under development throughout the world (Wohlers, 1993). The problem of this study was to evaluate each of six preselected RP systems based on key characteristics. This study provides pertinent data so that those teams and individuals involved in the implementation and the use of a RP process can make sound decisions.