Digital Commons Network^™

Modeling Diminishing Marginal Returns: An Application To The Aircraft Availability Model, Wayne L. Zorn

Theses and Dissertations

The Aircraft Availability Model (AAM) provides the Air Force with a worldwide peacetime requirement for reparable spare parts. This research models AAM methodology as it relates to the concept of diminishing marginal returns in resource application. Three separate modeling techniques are investigated with the goal of reformulating the AAM as a mathematical programming model that provides a comparable solution and a capable tool for the conduct of sensitivity analysis. The general formulations presented here are continuous non-linear, continuous linear, and piecewise linear discrete/continuous models. Two formulations of the piecewise linear discrete/continuous model are presented. The piecewise linear model based on …

A Methodology For The Analysis And Prediction Of Air Force Officer Retention Rates, Mark A. Basalla

Theses and Dissertations

The purpose of this study is to investigate the effects of certain national economic conditions and certain Air Force related conditions on officer retention rates and to build, verify, and validate a multivariate linear regression model to be used by Air Force personnel management officials that will predict officer retention rates for rated and non-rated line officers aggregated by Yeargroups and AFSC groups. Previous retention models were reviewed to study possible predictors and methodologies.

Measuring The Impact Of Programmed Depot Maintenance Funding Shortfalls On Weapon System Availability, Donald F. Hurry

Theses and Dissertations

This study used the Poisson regression technique, bootstrap estimates, and the Kaplan-Meier estimates for survivor curves to determine the impact of Programmed Depot Maintenance (PDM) on weapon system availability. More specifically, these techniques estimated the effect in the number failures per year due to PDM, but the bootstrap technique also estimated the effect in the amount of downtime experienced by a weapon system due to PDM. Although the Poisson regression model did not pass the rigors of statistical testing, the Poisson regression suggested differences in the number of failures per year between PDM and no-PDM weapon systems. The results of …

A Methodology To Assess The Air Force Materiel Command's Exercise Support Program's Weighting Scheme, Gilbert D. Ness

Theses and Dissertations

This research performs analysis on the Air Force Materiel Command's Exercise Support Program's Weighting Scheme so that decision makers can create a more efficient and effective Resource Allocation - Integrated Process Team (RA-IPT) manpower allocation process. A linear programming (LP) model was derived from the Exercise Support Program (ESP) to assign manpower reductions throughout the Mission Element Board (MEB) organizational level in AFMC. Parametric analysis was performed on the LP model by simultaneously changing multiple objective function coefficients with the use of various direction vectors. These direction vectors were applied with the use of an incrementally increasing scalar step size …

An Investigation Of Preliminary Feature Screening Using Signal-To-Noise Ratios, David B. Sumrell

Theses and Dissertations

A new saliency metric and a new saliency screening method are developed. This new metric, the SN saliency metric, is based upon signal-to-noise ratios, where the signal is provided by a sum of squared weights associated with a given feature, and the noise is based upon a sum of squared weights associated with a reference noise feature which is injected into the data. The resultant metric allows for a direct comparison of the feature of interest with a reference noise feature which is known to be nonsalient. The SN saliency screening method, which uses the SN saliency metric, offers the …

A Response Surface Methodology Approach To Groundwater Model Calibration, Jeffrey B. Rowland

Theses and Dissertations

This thesis examined the effect of parameter bounding, a reduced data set, and data enrichment techniques on a response surface methodology (RSM) approach to groundwater model calibration. The four phases of the study included a calibration using a very dense data matrix, a calibration using a sparse calibration matrix, an evaluation of several data enrichment techniques, and a calibration using a data matrix enlarged with the use of the best enrichment technique. All calibrations were conducted using only a first order approximation to the response surface and with bounds placed on the input parameters. The first two calibrations using the …

Optimization Analysis For Design And Planning Of Multi-Project Programs, Victor D. Wiley

Theses and Dissertations

Program Management concerns the long-term planning, coordination, and control of major technological, engineering, scientific, and/or developmental activities. In general, programs tend to be exceptionally large, consisting of several parallel or sequential projects or groups of projects. While many of the approaches developed for projects have been used in program management, there are critical differences between programs and projects. A key difference is the magnitude of programs, both in program duration and number of tasks to be coordinated. In addition, project parameters are driven by program decisions. While a large number of modeling efforts have focused at the project level, very …

Applying Response Surface Methodology To Readiness-Based Leveling Of Reparable Items, Todd E. May

Theses and Dissertations

Reparable items play a large role in determining the readiness of United States Air Force weapon systems. Many factors characterizing flying tempo and item repair and transit time influence the level of fleet readiness. Readiness-Based Leveling (RBL) considers these factors as it seeks to maximize aircraft readiness as it allocates spare reparable items between bases and a depot. The purpose of this research was to demonstrate the validity of using response surface methodology (RSM) within the context of RBL in an effort to quantify the influences these factors have on aircraft readiness. RSM applied designed experiments and least squares regressions …

Development Of A Decision Support System For The Department Of Energy's Selection Of Waste Site Remediation Technologies, Brian E. Ralston

Theses and Dissertations

The Department of Energy is faced with the complex decision of selecting technologies for waste site remediation. This research focused on developing a decision support system to aid the decision maker in selecting the best strategy of remediation technologies. A decision analysis model was developed which incorporates life cycle cost data, risk information, and user input, to analyze the technology choices. The research outlined the use of multiple attribute utility theory using exponential attribute utility functions with a simple additive objective function. The best available data was used to demonstrate the capabilities of the model. The model provides the decision …

A Study Of The Integration Of Language Arts In An Elementary Music Curriculum, Kimberly Ann Kell

Theses and Dissertations

The problem of this study was to determine the effects of the integration of the language arts in a first grade music curriculum.

Two first grade classes from the Marie D. Durand Elementary School, in Vineland NJ, participated in the study. The groups received 12 weeks of an integrated language arts music curriculum based on materials from Harcourt, Brace, and Jovanovich (HBJ) reading series and Carson-Dellosa "Phonics Fun K-1." The two control groups, which also consisted of first grades, received traditional music instruction, with no specific emphasis on the language arts.

For problem one, a survey was administered to all …

Riblet Effects On Gortler Vortex Development Over A Concave Surface, James A. Rothenflue

Theses and Dissertations

Riblet effects on Goertler vortex development in laminar and transitional flows were measured using three-dimensional laser-Doppler anemometry. Three freestream velocities were tested such that riblet spacing corresponded to Goertler vortex (GV) wavelengths which presumably would be either strongly amplified, weakly amplified, or attenuated by centrifugal forces on a curved surface. Experiments revealed the development of paired, counterrotating vortices within the riblet valleys over both flat and concave surfaces. For riblet spacings equivalent to weakly or non-amplified GV wavelengths, GV development on a curved surface was above the riblets and was delayed by the addition of riblets. The GV wavelength was …

Occupational Sex Type And Gender Differences In Vocational Preference: An Internal Analysis Of Item Bias On Selected Items Of The Strong Interest Inventory Using Dif Procedures., Jesse R. Aros

Theses and Dissertations

Presenting problem. The measurement of expressed occupational preference continues to be affected by occupational sextyping, a non-interest related variable. Teasing out bias (sextype) from restrictiveness (real and artifact gender differences) is needed to help improve sex-fairness in vocational measurement. Occupational sextyping may affect internalizations of external expectancies of what one should be like or likes as much as what an individual is truly like or likes, altering preference.Research and methods. Responses were obtained from an anonymous data pool (n = 16,484) of 18-22 year olds who submitted their SII to the test publisher for scoring. Mean age and standard deviation …

Nature Among The Mormons: An Ecocritical Approach To Mormon Literature, Gail D. Ballard

Theses and Dissertations

Increasingly, environmentalists have focused on Judeo-Christian tradition as the cause of Western culture's ecological crisis. It is the purpose of this paper to examine the charges against Judeo-Christian tradition and to show how the revealed doctrines of The Church of Jesus Christ of Latter-day Saints provide possible solutions to environmental challenges. The resulting Latter-day Saint environmental paradigm will be superimposed on selected Mormon literature to determine how effectively the doctrines taught by Church authorities filtered into popular Mormon culture.

Despite the inspired teachings of Latter-day Saint prophets, Mormons remain unimpressive in their environmental practices. My research will show that while …

A Doctoral Degree In Aviation Science: The Need, Curriculum Content, And Other Considerations As Perceived By Aviation Educators Holding Doctoral Degrees, Barry Robert Beck

Theses and Dissertations

The primary purpose of this study was to determine if there is a need for a doctorate in aviation, what content areas should be included in the doctoral program, and what type of degree should an aviation doctoral program establish, as perceived by doctorally-prepared aviation educators. A two-round Delphi method was used to obtain a consensus from a group of doctorally-prepared experts on the content areas for doctoral programs in nonengineering aviation science. The panel of 100 experts were all doctorally-prepared and were members of the University Aviation Association, or if not members of the UAA, were working in collegiate …

Development Of Quasi-Likelihood Techniques For The Analysis Of Pseudo-Proportional Data, Jennifer A. Elder

Theses and Dissertations

In certain experimental situations, the data observed are pseudo-proportional. By this, we observe the numerator, the number of responders, but the denominator, the total number, is random and, possibly, unobserved. In such situations, the data often exhibit "extra" variability due to the randomness of the denominator. Analysis of these data should account for this overdispersion. Several authors have proposed parametric approaches to this problem. Finney [Biometrika (1949) 36, 239-256] proposed the use of a mixture of the binomial and Poisson distributions. Anscombe [Annals of Applied Biology (1949) 36, 203-205] discussed the use of a mixture of the binomial and negative …

Calliphysics, Sara Miller Clark

Theses and Dissertations

My work focuses on the reality and life of mental objects. The unseen masquerade as the seen, not only in our mind's eye but as an immediate visual experience.

To realize this I apply volumetric form to models of thought and present them in a variety of environments. The forms are derived from the fields of science and mathematics, specifically geometry and topology. Topology or "rubber-sheet geometry," is the study of shapes whose essential attributes are unchanged by continuous deformation. The shapes are not defined by measurements of distance and angle, but by whether they can be transformed when bent, …

Interactions Among The Stationary Phase, The Mobile Phase, And The Solute In Liquid Chromatographic Systems, Zengbiao Li

Theses and Dissertations

Interactions among the stationary phase, the mobile phase, and the solute in liquid chromatography' have been studied. A strong dependence of the stationary phase properties on the mobile phase composition may arise from their interactions.

The solvatochromic comparison method, which can give estimates for the dipolarity-polarizability, the hydrogen-bonding acidity, and the hydrogen-bonding basicity of a solvent, represented by the solvatochromic parameters π⁺, α and β, respectively, was used to study the surface properties of silica in the presence of n-hexane-chloroform or n-hexane-ethyl ether mixtures. A high dipolarity- polarizability, a high hydrogen-bonding acidity, and a low hydrogen-bonding basicity …

Power Analysis For The Mixed Linear Model, Cheryl Annette Dixon

Theses and Dissertations

Power analysis is becoming standard in inference based research proposals and is used to support the proposed design and sample size. The choice of an appropriate power analysis depends on the choice of the research question, measurement procedures, design, and analysis plan. The "best" power analysis, however, will have many features of a sound data analysis. First, it addresses the study hypothesis, and second, it yields a credible answer.

Power calculations for standard statistical hypotheses based on normal theory have been defined for t-tests through the univariate and multivariate general linear models. For these statistical methods, the approaches to power …

Combustion Modeling Of Rdx, Hmx And Gap With Detailed Kinetics, Jeffrey E. Davidson

Theses and Dissertations

A one-dimensional, steady-state numerical model of the combustion of homogeneous solid propellant has been developed. The combustion processes is modeled in three regions: solid, two-phase (liquid and gas) and gas. Conservation of energy and mass equations are solved in the two-phase and gas regions and the eigenvalue of the system (the mass burning rate) is converged by matching the heat flux at the interface of these two regions. The chemical reactions of the system are modeled using a global kinetic mechanism in the two-phase region and an elementary kinetic mechanism in the gas region. The model has been applied to …

Teachers Of The Lost Year, 1958-1959: Little Rock School District, Sondra Hercher Gordy

Theses and Dissertations

The Little Rock Central High Crisis of 1957 has been examined by numerous scholars from a variety of perspectives. Much less research has been devoted to the following year--the Lost Year, 1958-59--when Little Rock high schools were closed to all students, black and white. The entire period surrounding these two academic years found this Southern American community electrified with racial conflict, societal disruptions, and political machinations. Though all people in the community were affected by such unsettling times, no lives were more disrupted than those of teachers. Closed schools meant the interruption of professional careers. The confusion within the community …

Application Of Autoregressive Moving Average Linear Prediction Filters To The Characterization Of Solar Wind-Magnetosphere Coupling, Carter N. Borst

Theses and Dissertations

Linear prediction filtering techniques have been used in studying the coupling processes between the solar wind and magnetosphere. The magnetosphere is a complex, dynamic system with at least two independent coupling methods for energy input, driven and unloading. Linear models were built and tested on the Bargatze data set, consisting of over 70 days of geomagnetic indices and solar wind data ordered in 34 intervals of increasing geomagnetic activity. Linear filtering techniques employing single-and multiple-input, autoregressive models predicted values of the magnetic index AL from solar wind data. The impulse response curves of the AL-coupling function groups showed amplitude peaks …

The Effects Of Non-Linear Bromide Adsorption On Apparent Macrodispersivity, Eron J. Dodak

Theses and Dissertations

Macrodispersivity estimates are crucial in predicting the subsurface transport of contaminants. These predictions have become increasingly important as the number of contaminated sites continues to increase. In addition, the longevity of many contaminants can affect water quality over extended periods of time.

Anionic tracers such as bromide and chloride are commonly used as groundwater tracers in dispersivity experiments because they are inexpensive, easily detected, and are commonly believed to behave conservatively. It has been found, however, that anionic tracers do not always behave conservatively; sediments with a net positive surface charge can adsorb some-of the tracer.

A weakly non-linear, experimentally …

A Survey Of Industrial Technology Graduates To Determine Their Perceptions Of Selected Competencies, Louis K. Wilson

Theses and Dissertations

No abstract provided.

Process Optimization Of Bench-Scale Packed-Bed Reactor For Ethane Hydrogenolysis, Syed M. Habibullah

Theses and Dissertations

No abstract provided.

The Cost Effectiveness Of Using Ondansetron Prophylactically Intraoperatively In Pediatric Tonsillectomy Patients, Beth Ann Owens

Theses and Dissertations

No abstract provided.

Analysis Of The Compressive And Tensile Properties Of Kevlar Fiber After Thermal Treatment, Fernanda Santos Philbrick

Theses and Dissertations

No abstract provided.

Probing Injury-Illness Information Of The Concordia Language Villages, 1991-1995, Linda E. Erceg

Theses and Dissertations

No abstract provided.

Mechanistic Model Of Multiphase Heat And Fluid Flow In Geothermal Wells, Peter T. Argument

Theses and Dissertations

No abstract provided.

The Use Of Exploratory Environments In The Teaching Of History, David L. Christian

Theses and Dissertations

No abstract provided.

Hydrogeological Characterization Of The Akzo Salt Company, Williston Facility, Williston, North Dakota, Jane K. Geiger

Theses and Dissertations

Operations at the Akzo Salt Company near Williston, ND, have resulted in saline contamination of the surface and subsurface in the general vicinity of the company property and possibly the surrounding area. The company site lies on the floodplain of Stony Creek and waste salt is buried just north of the plant. The salt dump poses surface and groundwater hazards. A recent flood on the plant site in August of 1993 resulted in groundwater corning into contact with buried salt. Groundwater quality and water level elevation data collected by the North Dakota Health Department, the North Dakota Geological Survey and …