Digital Commons Network^™

An Integer Solution Heuristic For The Arsenal Exchange Model (Aem), Daniel J. Green

Theses and Dissertations

The Air Force Studies and Analyses Agency sought a method for converting the continuous solution produced by the Arsenal Exchange Model into a feasible integer solution. The current integerization method leaves weapons unused and targets uncovered and could be improved. In the method developed, the noninteger valued variables in the continuous solution are rounded down to the nearest integer to produce a truncated solution. An integer goal program is then used to reallocate the weapons and targets made available in the rounding process. The truncated solution is then combined with the solution of the integer goal program to produce a …

An Air Mission Planning Algorithm For A Theater Level Combat Model, Brian J. Griggs

Theses and Dissertations

This thesis describes the development of an air mission planning algorithm for the Joint Staffs Future Theater Level Model FTLM. The overall problem scope was to develop an algorithm to handle major factors bearing on the combat mission planning problem while providing hook-ups for the FTLM architecture. Other aspects of the problem included finding the appropriate level of detail, developing a fast solving technique, and attempting to use existing data. The problem was handled by using some ideas from existing aircraft allocation algorithms and by adding some new techniques. The proposed air mission planning algorithm supplies the optimum degree of …

An Analysis Of Stopping Criteria In Artificial Neural Networks, Bruce Kostal

Theses and Dissertations

The goal of this study was to decide when to terminate training of an artificial neural network ANN. In pursuit of this goal, several characteristics of the ANN were monitored throughout ANN training classification error rate of the training set, testing set, or a weighted average of the two moving average classification error rate measurements of the difference between ANN output and desired output error sum of squares, total absolute error. or largest absolute error or ANN weight changes absolute weight change, squared weight change, or relative weight change. Throughout this research, the learning rate was held constant at 0.35. …

An Investigation Of Simulated Annealing Applied To Structural Optimization Problems, Richard C. Mceachin

Theses and Dissertations

This thesis investigates the feasibility of using Simulated Annealing SA in structural optimization problems. The investigation involves solving benchmark structural optimization problems with an SA algorithm, and comparing its solutions to those found by four other optimizers. Overall, the analysis shows that SA has limited applicability in structural optimization. Two primary factors were found to adversely impact the performance of the SA algorithm in these problems. These factors are high dimensionality, and high levels of constraint. The difficulty involved in solving these problems with a random search increases exponentially with the number of dimensions. The number, and non-linearity, of the …

The Use Of L-Moments To Fit The Generalized Lambda Distribution To Sample Data, Robert B. Mohan

Theses and Dissertations

The Generalized Lambda Distribution GLD is a four-parameter, continuous probability distribution that is useful for simulation analysis. The strengths of the GLD lie in its abilities to approximate many distributions, represent data when the underlying distribution is unknown, and fit or generate random variates. The method of moments is presently the accepted technique for estimating the parameters of this distribution. However, it is sensitive to extreme observations and subject to large sampling variability as the sample size decreases. L-moments are expectations of certain linear combinations of order statistics. They can be used to estimate parameters and quantiles of probability distributions. …

An Analysis Of Air Force Acquisition Engineering Officer's Perceptions Of The Adequacy Of Their Preparation For Management, Steven E. Woodruff

Theses and Dissertations

The purpose of this study was to determine how much time Air Force acquisition engineers spend in performing management functions, how those engineers spend in performing management functions, how those engineers perceive their management training, and which types of training contribute the most to managerial competency. The results from surveys of 215 acquisition engineers assigned to ASCEN, Wright-Patterson AFB, OH and their supervisors revealed that engineers do indeed spend substantial amounts of time performing management functions. Slightly more than half the engineers reported spending at least 50 of an average workday performing management functions. Over 53 of engineers responding to …

Rapid And Accurate Timing Simulation Of Radiation-Hardened Digital Microelectronics Using Vhdl, Charles P. Brothers Jr.

Theses and Dissertations

This dissertation presents the development of a fast, accurate, timing simulation capability based on VHSIC Hardware Description Language VHDL without the use of back annotation of timing delay information. This VHDL-based timing simulator is intended for use with radiation-hardened microelectronics in simulating timing of circuit operation in pre-radiation, post-radiation 1 MradSi total dose, and ionizing dose radiation environments. Development of the timing models are presented. The implementation of the timing models are incorporated into a VHDL library composed of basic logic gates and flip-flops. Simulations of complex circuits were run in SPICE and VHDL to assess the timing accuracy and …

Point And Interval Estimation Of Series System Reliability Using Small Data Sets, Craig J. Willits

Theses and Dissertations

This investigation explored the relative performance of several small-sample point and interval estimators for series system reliability. Among point estimators, the maximum likelihood estimator MLE was compared to the corresponding Bayes estimator. In addition, four interval estimators were compared Easterlings modified maximum likelihood integer estimator, the Lindstrom-Madden estimator, and Bayesian probability interval estimators constructed using approximate beta and Bayes Monte Carlo empirical posterior densities. The relative performance of the point estimators was assessed by comparing their mean square errors. For the four interval estimators, the interval coverage probability and the average interval lower bound were examined. The values of these …

Compression Of A Radar Track Of A Near Earth Satellite Into An Earth Centered Inertial State Vector Using Least Squares Differential Correction, Garry L. Hall

Theses and Dissertations

This study investigated the use of a least squares differential corrector to compress the information contained in a single radar track of a Near Earth satellite into a six element, Earth Centered Inertial state vector and associated covariance matrix. Observations were generated using a truth model program based on two body, J2 geopotential, and atmospheric drag dynamics and consisted of simulated range, azimuth and elevation. Random Gaussian noise was added to the data to simulate real world random errors. The orbital dynamics used in the estimator consisted of two body and J2 geopotential effects which were approximated using a Taylor …

A Shock Tube Study Of Aerodynamic Heating Of Gaps In A Cylinder Subjected To Supersonic Cross Flow, Douglas D. High

Theses and Dissertations

The effects of localized aerodynamic heating in cylinder expansion gaps positioned in cross flow were investigated in a shock tube. For this study, Mach number and Reynolds number were varied from 1.04 to 1.38 and 5 x 105 to 9 x 105, respectively. The cylinder was instrumented with quick response time thermocouples positioned on the surface of the cylinder, the wall of the gap, and the gap floor. Gap aspect ratios varied from 1.23 to 3.69. Pressure gauges were used to measure wave shock speeds, pressure ratios, and transient pressure conditions. Surface temperatures were measured and converted to heat fluxes …

The Prediction Of Pilot Opinion Ratings Using Optimal And Sub-Optimal Pilot Models, Craig R. Edkins

Theses and Dissertations

This study details the development of a sub-optimal pilot model that blended the classical and optimal pilot model approaches in an attempt to achieve the advantages of each. This model used a numerical solution to the linear quadratic Gaussian problem to find the pilot gain, lead, and lag values that minimized a performance index consisting of task error and control usage. This development was conducted in four phases. First, an optimal pilot model developed by Systems Technology, Incorporated, was analyzed in detail. This analysis included a step-by-step example problem to clarify the model's logic and an in-depth sensitivity analysis of …

A Format For Storing And Managing Multiple Level Of Detail Terrain For Simulated Environments, Keith L. Meissner

Theses and Dissertations

This study investigated a method of storing, managing and rendering terrain data, while addressing conflicting goals of. rendering speed, display detail and memory usage. A data structure is presented to store terrain data, with an object oriented system to manage the data stored in the structure. The structure stores terrain data in a compact form which is converted into rendering structures in real time. The structure uses levels of detail to maintain display detail. The structure is compared against an existing format for storing terrain data, MultiGen Flight. The system managing the structure is shown to decrease memory usage and …

An Analysis Of The Effects Of Modeling Brigade Templates In Camex, Douglas A. Hersh

Theses and Dissertations

This thesis effort modeled brigade-sized templates within the CAMEX model, and determined the effects of those templates on the direct fire attrition methodology. The model simulated combat between a U.S. brigade from a mechanized or armored division and a Soviet-style motorized rifle regiment. Three different scenarios were used to simulate combat between the forces. The scenarios included a movement to contact, an attack, and a deliberate defense. Each scenario was run using the battalion-sized templates and again with the brigade-sized templates. The results revealed that use of the model with brigade-sized templates will demonstrate similar results to those obtained using …

Electrochemical Studies Of The Carbon-Oxygen Bond Cleavage For Alkyl Aryl And Diaryl Ethers., Yizhong Sat

Theses and Dissertations

Radical anions of 9-phenoxyanthracene (1) and 9-phenoxyphenanthrene (2) were generated on platinum in dimethylformamide/tetra-n-butylammonium perchlorate at $-$1.84 V vs. SCE and $-$2.37 V, respectively. Dianions of 1 and 2 were produced at $-$2.58 V and $-$2.95 V, respectively. Chronoamperometric techniques demonstrated that radical anions of 1 and 2 have their half-lifes greater than 1000 seconds and 200 seconds, respectively. The radical anions of 1 and 2 underwent an unimolecular bond scission at the aryl carbon-oxygen bond to generate aryl radicals and phenoxide ions. The cleavage reaction for the radical anion of 1 at the anthryl carbon-oxygen bond was found to …

Automation Of Formation Flight Control, Vincent P. Reyna

Theses and Dissertations

The research contained in this thesis explores the concepts of Automated Formation Flight Control documented in three previous AFIT theses. The generic formation analyzed consists of a Leader and Wingman, with the Wingman referencing its maneuvers off of Leader maneuvers. Specifically, planar formation flight control concerning only heading and velocity changes is considered. Next, the vertical separation constraint is relaxed to allow wing maneuvers outside of the flight plane of the lead in order to minimize the energy expended by the wing in a maneuver. Analysis of the two forms of formation flight control investigated in this thesis reveals the …

Evaluation Of Air Force And Navy Demand Forecasting Systems, Christian J. Dussault

Theses and Dissertations

In March 1993, the JLSC selected the Navys Statistical Demand Forecasting System as the standard DOD forecasting system. The purpose of this study was to evaluate and compare the performance and accuracy of the Navy Statistical Demand Forecasting system, relative to the Air Force Requirements Data Bank forecasting system in an Air Force environment. To compare the performance of each forecasting system, the research used three different approaches. The first approach looked at time series components and evaluated how each forecasting system reacted to different data patterns. From this approach, it was found that under the presence of a trending …

Active Latter-Day Saint Working Mothers: Their Effect On Their Daughters' Future Plans, Nissa C. Bengtson Allred

Theses and Dissertations

This research looks at the effect employed active LDS mothers have on their daughters' future plans for education, career, marriage, and children. Mothers' educational level, type of employment, and daughters' attachment to the LDS church were taken into consideration. It was found that a majority of daughters are definite in their plans for education, career, marriage, and children regardless of the employment status of their mother. Daughters of employed LDS mothers are more definite in their plans for a career than daughters of unemployed LDS mothers. No effect was found for mothers' employment on daughters' future plans for college, marriage, …

An Examination Of The Relationship Between Parental Attitudes And Student Achievement On Standardized Test Scores In Mathematics, Susan S. Lapp

Theses and Dissertations

The purpose of this study was to examine the relationship between parents' attitudes toward mathematics and students' standardized test scores in mathematics. Eighty-four parents of fourth-grade students in a southeastern military dependent school system were surveyed to determine their attitudes to mathematics when they were in elementary school and their attitudes about mathematics today. Parents also responded to questions about their children's abilities and attitudes toward mathematics.

Total scores for the survey were matched with the students' mathematics scores on the Iowa Test of Basic Skills (ITBS). The Pearson Product-Moment Correlation was used to compute the correlation coefficients. A positive …

Predicting Missionary Service, Bert Burraston

Theses and Dissertations

The purpose of this thesis was to test the antecedents of religiosity on religious commitment. Specifically, what dimensions of religiosity predict if a young-adult Mormon male will serve a mission. Both Logistic Regression and LISREL were used to examine data from the Young Men's Study, in order to predict Mission. The six variables, Religious Intention, Public Religiosity, Religious Negativism, Family Structure, Tithing, and Smoking were found to have direct effects on missionary service. Four more variables were found to have important indirect effects on Mission. The four variables are Parents Church Attendance, Home Religious Observances, Agree With Parents' Values, and …

Adjusting Holt-Winters Exponential Smoothing For External Intervention: A Mathematical Technique For Making Quasi-Judgmental Adjustments For Anticipated Changes, Daniel Wayne Williams

Theses and Dissertations

Public administration data is sometimes extrapolated through exponential smoothing. Sometimes such data may undergo a level shift because of a policy decision. The slope of the curve formed by connecting the periodic observations increases or decreases significantly for a brief period, thereafter returning to a slope similar to the slope preceding the policy change. This discontinuity might be called a ramp or a step. Forecasts made with exponential smoothing immediately before, during, or immediately after the ramp or step may be considerably inaccurate unless adjusted. A technique called adjusted exponential smoothing is proposed to reduce or eliminate the inaccuracy of …

The Impact Of Advanced Information Technologies On Architecture And Engineering Design Firms: A Field Study, Mcdonald Davis Iii

Theses and Dissertations

The research investigated architecture and engineering design firms that have a reputation for being competent in the utilization of advanced information technologies. It is believed that competency in the use of these technologies has contributed to the ability of A&E design firms to perform engineering design services effectively and efficiently.

Review of the literature suggests that the use of advanced information technologies has had lasting interactive effects on the strategy, structure, management, tasks, and the personnel of organizations. There does not, however, appear to be any dissertation research on the impact of advanced information technologies on architecture and engineering firms. …

The Standardized Influence Matrix And Its Applications To Generalized Linear Models, Jiandong Lu

Theses and Dissertations

The standardized influence matrix is a generalization of the standardized influence function and Cook’s approach to local influence. It provides a general and unified approach to judge the suitability of statistical inference based on parametric models. It characterizes the local influence of data deviations from parametric models on various estimators, including generalized linear models. Its use for both robustness measures and diagnostic procedures has been studied. With global robust estimators, diagnostic statistics are proposed and shown to be useful in detecting influential points for linear regression and logistic regression models. Robustness of various estimators is compared via. the standardized influence …

Validation Of A Virginia Work Release Risk Prediction Model: A Methodology For The Improvement Of The Reliability Of Correctional Decision Makers, William Nathan Osborne Jr.

Theses and Dissertations

This study identifies and validates variables which are significant predictors of work release success on 439 Virginia work release participants. The variables were selected on the basis of whether they would exert internal or external control over the inmate, with a view toward offering empirical support to control theory. A retrospective longitudinal research design was employed by randomly selecting inmates who had participated in either of three work release centers from 1987 to 1991. Two of the programs housed male inmates while the other housed female inmates. Data were collected from inmate files on thirty-one variables over a six month …

Trust In A Medical Expert System: An Exploratory Study, Anthony John Moffa

Theses and Dissertations

Operator trust in the abilities of an expert system can be crucial, especially in a high risk setting like the medical field. No studies have attempted to measure trust in a medical diagnostic aid. In the present research, diagnostic agreement and number of trials of an abdominal pain diagnostic aid were manipulated. The scenarios and feedback of the diagnostic aid were limited for purposes of control. Participants entered cases into the computer-based aid. Effects on operators’ trust were measured subjectively. The trust metric consisted of an overall trust question as well as questions representing two models of trust between humans …

Einstein's Equations In Vacuum Spacetimes With Two Spacelinke Killing Vectors Using Affine Projection Tensor Geometry, Miles D. Lawrence

Theses and Dissertations

Einstein's equations in vacuum spacetimes with two spacelike killing vectors are explored using affine projection tensor geometry. By doing a semi-conformal transformation on the metric, a new "fiducial" geometry is constructed using a projection tensor fields. This fiducial geometry provides coordinate independent information about the underlying structure of the spacetime without the use of an explicit form of the metric tensor.

Reliability Of The Scoring Criteria Of The Test Of Problem Solving-Adolescent, James R. Culbertson

Theses and Dissertations

No abstract provided.

A High Resolution Gravity Survey For The Detection Of Pleistocene Aquifers Underlying The Fort Berthold Indian Reservation, North Dakota, Mark R. Mcdonald

Theses and Dissertations

A high resolution gravity survey was performed over portions of McLean, Mountrail, and Ward Counties in central North Dakota during the fall and winter of 1990-1991. The study was performed to locate and map Pleistocene sand and gravel aquifers. Well data indicate that aquifers beneath the study area range in thickness from 1 to 60 meters. The Bouguer gravity anomalies resulting from these shallow aquifers was estimated to be on the order of 1 to 2 mgals. Previous studies have focused on available well data and by mapping topographic lows. Due to the inferential nature of these studies, the detailed …

A Comparison Of Wellhead Protection Area Delineation Methods At Larimore, North Dakota, Barbara L. Sahl

Theses and Dissertations

Many communities in North Dakota rely on water from shallow, unconfined aquifers that are vulnerable to contamination. A strategy to protect public groundwater supplies is the delineation of wellhead protection areas (WHPAs) around the area which contributes water to a well. Several delineation methods are available, all of which have simplifying assumptions which affect the size or shape of a predicted WHPA.

Five WHPA delineation methods were compared to determine which simplified the aquifer/well system while preserving essential hydrogeologic features. A simple system may not require a complex model to predict an accurate WHPA. Sensitivity of each to changes in …

Preferential Flow Mechanisms : Their Interaction And Effect On Dye Movement In Till And Glaciolacustrine Sediment, Calvin D. Taylor

Theses and Dissertations

Contamination of groundwater by agricultural chemicals is of concern to the population of the Northern Great Plains. Preferential flow (macropore, finger, and funnel) allows such chemicals to move relatively rapidly through materials considered to be aquitards. Preferential flow mechanisms at two sites in North Dakota, one in till, the other in glaciolacustrine sediments were determined by application of blue dye (FD&C No 1) solution to framed sites (9m2 & 4m2) with the topsoil removed. The sites were then cored and blocks hand-excavated to depths of 1.5 and 2.5-meters. The three types of preferential flow (macropore, finger, and funnel) were analyzed …

Diagenetic Controls Of Reservoir Quality In The Mississippian Wayne Beds In The Williston Basin, Bottineau County, North Dakota, Michael M. Wetmore

Theses and Dissertations

The carbonate Wayne beds of the Frobisher-Alida interval (Mississippian Mission Canyon Formation) in the Williston Basin, North Dakota, are capable of producing as much as 400,000 barrels of oil per well at depths of only 3,100 feet. Wayne production is from structural traps in the intertidal packstone-wackestone lithofacies; however, the ultimate recoverable reserves of oil per well is controlled neither by structure, nor by depositional environments.

The Wayne beds underwent cementation and micritization in the marine phreatic diagenetic environment. Hypersaline diagenesis caused minor dolomitization and anhydritization. Dissolution and minor cementation occurred in the freshwater vadose zone. Freshwater phreatic diagenesis resulted …