Digital Commons Network^™

Luminescence Study Of Ion-Implanted Gallium Nitride, Eric Silkowski

Theses and Dissertations

Luminescence and absorption measurements were used to demonstrate the efficacy of ion implantation for introducing various classes of dopants into GaN. A wide range of implantation and annealing studies were performed with several dopant species (Ar, Zn, C, O, Si, Be, Mg, Nd, Er). Room temperature ion implantation was performed on MOCVD- and MBE-grown GaN samples at energies between 100 and 1150 keV with doses ranging from 1 x 10¹³ to 1 x 10¹⁵/cm^-2. Conventional furnace annealing in flowing NH₃ or N₂ gas resulted in good implantation damage recovery at an annealing temperature …

Development Of Site Characterization Simulator Specifications, Jeffrey L. Heiderscheidt

Theses and Dissertations

The purpose of this study was to develop a tool for evaluating data quality when characterizing a potentially contaminated groundwater aquifer, and to provide a basis for developing a simulator to allow environmental managers and engineers to practice and learn about the site characterization process. Specifically, this study characterized the uncertainty, estimation block size, and cost for the various methods of determining the value of each geological, hydrological, and contaminant parameter necessary to characterize a site. Research entailed identifying site characterization objectives and identifying parameters necessary to obtain those objectives. Methods of estimating each parameter were identified, then research was …

Optical Detection Properties Of Silicon-Germanium Quantum Well Structures, Michael R. Gregg

Theses and Dissertations

A study has been carried out on Si/SiGe multi quantum well structures to determine their applicability as normal incidence infrared detectors in the spectral range of 2-12 micrometers. The research effort was primarily experimental; however, extensive calculations were performed to initially explain the experimental data and then used to design subsequent structures. Multiple quantum well structures grown on both Si[001] and Si[110] substrates via molecular beam epitaxy were studied by photoluminescence, absorption, and photoresponse measurements over a wide parameter space. Variables included quantum well depth and width, well doping, number of wells and growth temperature. Well widths were varied from …

Maximum Likelihood Estimation Of Exponentials In Unknown Colored Noise For Target In Identification Synthetic Aperture Radar Images, Matthew P. Pepin

Theses and Dissertations

This dissertation develops techniques for estimating exponential signals in unknown colored noise. The Maximum Likelihood ML estimators of the exponential parameters are developed. Techniques are developed for one and two dimensional exponentials, for both the deterministic and stochastic ML model. The techniques are applied to Synthetic Aperture Radar SAR data whose point scatterers are modeled as damped exponentials. These estimated scatterer locations exponentials frequencies are potential features for model-based target recognition. The estimators developed in this dissertation may be applied with any parametrically modeled noise having a zero mean and a consistent estimator of the noise covariance matrix. ML techniques …

Teachers' Attitudes Toward The Inclusion Of Young Children With Special Needs Into Regular Early Childhood Classes, Marilyn I. Forbes

Theses and Dissertations

All children have special abilities and special needs that make them unique individuals. Most teachers work with children who have a wide range of abilities and learning styles. Early childhood teachers are no exception. They may have children enrolled in their classrooms who have subtle learning disabilities, significant physical, mental or emotional problems, high intelligence, or conditions which limit speech and motor development. Teachers may not have been taught that the continuum of development is similar for all children, but that timetables may vary. This thesis examines staff attitudes toward the placement of young children with special needs into regular …

Validity And Norm Development For The Composite Examination Of Mental Status, Antoinette L. Jarnes

Theses and Dissertations

The Composite Exam of Mental Status (CEMS) is an instrument designed to screen patients for dementia and other cognitive impairments. This test is comprised of 12 subsections each requiring different cognitive abilities to complete. Areas assessed are Attention/Concentration, Orientation, Immediate Recall, Spontaneous Recall, Cued Recall, Naming, Verbal Fluency, Writing, Planning, Mental Flexibility, Construction and Abstract Reasoning.

The purpose of this study was to conduct concurrent validity analyses and initial norm development of the CEMS. The archival data for this study had been collected at 2 nursing homes in the upper midwest over a one year period. There were 168 (males …

Electromagnetic Scattering From Semi-Infinite Planar Arrays, Peter J. Collins

Theses and Dissertations

A hybrid method of moments (MM) based numerical model for the electromagnetic scattering from large finite by infinite planar slot arrays is developed. The method incorporates the novel concept of a physical basis function (PBF) to dramatically reduce the number of required unknowns. The model can represent a finite number of slot columns with slots oriented along the infinite axis, surrounded by an arbitrary number of coplanar dielectric slabs. Each slot column can be loaded with a complex impedance, allowing one to tailor the edge currents to provide a desired echo width pattern. The surface equivalence theorem is used to …

The Implementation Of An Enhanced Activity-Based Costing Model At The Defense Supply Center Columbus, James A. Neice Jr., Vernon L. Scribner

Theses and Dissertations

This research explored the problems with ABC implementation at a government service organization. ABC implementation efforts within other government organizations were examined to determine what caused different organizations to implement ABC. Next a case study analysis was performed, following the implementation of an expanded ABC model within a government service organization. The research used unstructured open-ended interviews, on-site visits, and archival analysis to conduct the case study. The study examined how the organization developed its initial model and subsequently introduced an enhanced model. The enhanced ABC Model had not been implemented at DSCC as of the conclusion of this case …

The Design Of A Financial Management Database System, Edward G. Leszynski

Theses and Dissertations

This research led to the design and development of a financial management database system for the Aeronautical Systems Center (AS C) Environmental Management (EM) Systems Program Office (SPO), which has the responsibility of managing the environmental contracts for the Government-Owned, Contractor-Operated (GOCO) plants that are owned by the Air Force. This thesis investigated the various 'development strategies' and 'methodologies' described in the Management Information Systems literature in order to devise an end-user development strategy capable of meeting the EM SPO's requirements. In addition, the information requirements, conceptual design and prototyping, and procedures phases of the System Development Life Cycle (SDLC) …

An Evaluation Of U.S. Air Force Aviation Fuel Consumption Factors To Accurately Predict Aviation Fuel Costs By Aircraft Mission, Design, And Series, Jodi A. Clayton

Theses and Dissertations

The purpose of this thesis was to undertake a systematic, scientific study of the accuracy of Air Force published fuel factors to estimate fuel costs at MAJCOM level by mission, design, and series (MDS) since the implementation of the Fuels Automated Management System (FAMS) under the current environment of decentralized aviation fuel (AVFUEL) funding. The research found that, at MAJCOM level, the use of USAF published AVFUEL factors in estimating out-year costs would have overstated costs in both fiscal year (FY) 1994 and FY 1995 by $2.5 M (FY 1994), by $.25 M (FY 1995), and may potentially understate costs …

Information Requirements Analysis: A Qualitative Characterization Of The Flightline Expediter For The Integrated Maintenance Information System, John C. Gorla Jr.

Theses and Dissertations

The Integrated Maintenance Information System (IMIS) concept design includes the addition of management tools to access IMIS databases and provide communication capabilities between flightline technicians and supervisors. Armstrong Laboratory has developed a portable maintenance aid for technicians, and sponsored this research to investigate the requirements for a computer based tool for the expediter, The basic hardware and software requirements document for IMIS, the System/Segment Specification (SSS), contains task information that closely corresponds to the expediter job description as defined in Air Combat Command Instruction 21-166. This research compiled a list of information requirements for the expediter from the IMIS SSS …

A Statistical Analysis Of Variables Related To Officer Retention, Gerald A. Scheuchner

Theses and Dissertations

The overall objective of this research effort was to statistically analyze survey responses which indicate the extent to which exiting officers say different variables affected their decision to separate. Two surveys were utilized for this analysis. These surveys were administered by the Air Force Personnel and Survey Branch in 1991 and 1993. The first analysis tested whether significant differences existed between rated and non-rated officers with regard to how strongly they feel about each of the variables with respect to their separation decision. The second analysis tested whether significant differences existed between the rated and the non-rated officers respectively, with …

A Study Of Defense Logistics Agency Inventory Classifications: Application Of Inventory Control Methods To Reduce Total Variable Cost And Stockage Levels, Wayne C. Goulet, Michael L. Rollman

Theses and Dissertations

This thesis analyzes the financial impact of applying a single inventory requirements model to three separate classes of inventory at the Defense Logistics Agency's (DLA) Defense Supply Center-Columbus (DSCC) commodity management facility. DLA' 5 blanket application of its variation of the Economic Order Quantity (EOQ) requirements model may not be appropriate for all levels of demand, possibly suboptimizing DLA's desire to minimize inventory costs while still providing an appropriate level of customer service. Simulation analyses of the DLA EOQ requirements model, the Silver-Meal heuristic, and Periodic Order Quantity models were conducted to examine which dynamic lot-sizing model is more effective …

Commercialization And The Small Business Innovation Research Program (Sbir): An Examination Of The Impacts Of Commercialization On The Small Businesses' Ability To Provide Research And Development Innovation To The Department Of Defense, Jennifer J. Thorpe

Theses and Dissertations

This research explored the small business's perceived ability to provide goods and services to the Department of Defense through the Small Business Innovation Research (SBIR) program. The research was sparked by the enactment of Public Law 102-564, which increased the emphasis in commercialization as a basis for contract award and required a business plan to demonstrate commercial potential and third-party funding commitments. Five SBIR participants in the acquisition of Air Force research and developments innovation, were investigated through case-study methodology. The research concluded that although the defense industries recognized the cumbersome nature of government procurement, they are eager to provide …

Recruitment Analysis Of Air Force Family Day Care Providers, Kimberly A. Rowe

Theses and Dissertations

This thesis is a qualitative, exploratory research effort which seeks to identify the motivators which influence Air Force Family Day Care (FDC) providers at Wright-Patterson AFB to enter and exit the FDC program. Two instruments were developed to measure the degree to which current and former FDC providers were influenced by various motivators identified through literature review and professional observation. Further, this thesis presents the results of the recruitment instrument which indicate the providers in the Wright-Patterson AFB FDC program are primarily motivated by their desire to remain home with their own children. The results also indicate there may be …

Privatization In Place And The Base Closure Community: Newark Air Force Base, Ohio, 1993-1995, Paul D. Pidgeon

Theses and Dissertations

This thesis studies the experience of the local community during the privatization in place of Newark Air Force Base (NAFB), Ohio. Licking County faced the loss of its largest employer after the 1993 Defense Base Closure and Realignment Commission (BRAC), a five-year commission established by President George Bush as a measure to cut national defense spending after the Cold War's end, recommended closing the Air Force repair facility. In its base closure recommendation, the BRAC gave the Air Force flexibility to craft a privatization in place plan. But the Air Force did not know how much the plan would cost …

Practical Implementation Of Multiple Model Adaptive Estimation Using Neyman-Pearson Based Hypothesis Testing And Spectral Estimation Tools, Peter D. Hanlon

Theses and Dissertations

This study investigates and develops various modifications to the Multiple Model Adaptive Estimation (MMAE) algorithm. The standard MMAE uses a bank of Kalman filters, each based on a different model of the system. Each of the filters predict the system response, based on its system model, to a given input and form the residual difference between the prediction and sensor measurements of the system response. Model differences in the input matrix, output matrix, and state transition matrix, which respectively correspond to an actuator failure, sensor failure, and an incorrectly modeled flight condition for a flight control failure application, were investigated …

Maximum Likelihood Estimation Of Exponentials In Unknown Colored Noise For Target Identification In Synthetic Aperture Radar Images, Matthew P. Pepin

Theses and Dissertations

This dissertation develops techniques for estimating exponential signals in unknown colored noise. The Maximum Likelihood (ML) estimators of the exponential parameters are developed. Techniques are developed for one and two dimensional exponentials, for both the deterministic and stochastic ML model. The techniques are applied to Synthetic Aperture Radar (SAR) data whose point scatterers are modeled as damped exponentials. These estimated scatterer locations (exponentials frequencies) are potential features for model-based target recognition. The estimators developed in this dissertation may be applied with any parametrically modeled noise having a zero mean and a consistent estimator of the noise covariance matrix. ML techniques …

Numerical Analysis Of Two And Three Dimensional Recessed Flame Holders For Scramjet Applications, Douglas L. Davis

Theses and Dissertations

This study investigated the flame holding properties of recessed cavities in supersonic flow using numerical analysis techniques. A simplified analytical model indicated that an important property for flame holding was the lower residence time. Several chemical kinetic rate models for hydrogen and hydrocarbon combustion were compared. The perfectly stirred reactor model also indicated that trace species diffusion should increase flame spreading rate, and that heat loss reduces flame holding limits. After nonreacting calibration, two-dimensional simulations confirmed the perfectly stirred reactor results for blowout limits. Also, the effect of trace species diffusion on flame spreading was shown to be negligible, and …

Development And Analysis Of A Dual-Role Fighter Deployment Footprint Logistics Planning Equation, Stanley E. Griffis, Joseph D. Martin

Theses and Dissertations

This research investigated the deployment footprint of a developing dual-role fighter, the Joint Strike Fighter (JSF). This thesis documents the creation of a point estimate linear equation and a spreadsheet model for deployment footprint analysis and provides three example applications of the spreadsheet model for the JSF. The development of the model focused towards direct application in the JSF acquisition process, however, this research also serves as a proof of concept for modeling any future weapon system's deployment footprint. The developed spreadsheet model allows the model manipulator to select a baseline weapon system then alter the various components which make …

A Follow-On Study Of University Efforts To Provide Students With The Ability To Comprehend And Apply Total-Quality Principles In Their Fields Of Study, Joseph J. Koizen, Michael D. Allen

Theses and Dissertations

This follow-on research investigated the educational processes employed by universities to enable their students to comprehend and apply Total Quality principles. The results of this research are intended to be used by Department of Defense institutions of higher education as a current guide to help them adopt practices which will enable their students to comprehend and apply Total Quality in their future assignments. Using a source list of schools from Quality Progress (Sept. 1995), contact individuals were interviewed at several civilian and military universities across the United States. Investigative questions were developed and asked concerning the specific educational processes of …

An Analysis Of Air Mobility Express Requirements Operating Within A Lean Logistics Wartime Environment, Jennifer A. Bollinger, Kellie L. Davila-Martinez

Theses and Dissertations

Lean Logistics was developed in response to budget cuts, force reductions, and a new political world order. The primary objective of Lean Logistics is to minimize the total system wide costs of the Air Force organization. Currently, the Air Force is seeking to cut costs by reducing inventories, improving repair processes, and employing faster transportation where possible. The purpose of this thesis is to determine if the Air Mobility Express (AMX) current sizing plan is capable of supporting the retrograde assets generated during the sustainment portion of a war. The Dyna-METRIC version 6.4 simulation program is employed to analyze the …

An Evaluation Of The Factors Used To Predict Writing Ability At The Air Force Institute Of Technology, Darrin E. Farr

Theses and Dissertations

A study of 574 students at the Air Force Institute of Technology compared performance, education, and experience factors (the later two as stated by the students themselves) to a locally developed estimate of true writing ability (WGPA). This exploratory research was additionally intended to assess the effectiveness of AFITs current writing student skill diagnostic and instructional system. Direct (essay evaluation) and indirect (objective test) evaluations of AFIT student writing ability were analyzed for their predictive impact. The statistical analysis procedures used in this study included the factor analysis of a survey, ANOVA, the adjustment of multiple correlations due to measurement …

The Impact Of Changes In Geographic Mobility On The Wages Of The Military Family Between 1985 And 1992, Barry M. Krauss

Theses and Dissertations

The purpose of this study was to examine what changes in the geographic mobility of the military family took place between 1985 and 1992, and this mobility's subsequent impact on the labor force participation of the military spouse, and the real wages of military family members. The study showed that mobility was significantly lower for military personnel and their spouses in 1992 than it was in 1985, the labor force participation and real wages for military spouses were greater in 1992 than they were in 1985, and real wages for military personnel declined between 1985 and 1992. A sensitivity analysis …

Calibration Of The Checkpoint Model To The Space And Missile Systems Center (Smc) Software Database (Swdb), Karen R. Mertes

Theses and Dissertations

This study analyzed the effect of calibration on the performance of the CHECKPOINT Version 2.3.1 software cost estimating model. Data used for input into the model were drawn from the FY 95 USAF SMC Software Database (SWDB) Version 2.1. A comparison was made between the model's accuracy before and after calibration. This was done using records which were not used in calibration, referred to as validation points. A comparison of calibration points, both before and after, was done in order to assess whether calibration results in more consistency within the data set used. Six measures such as magnitude of relative …

Background Graphics: A Decision-Making Hindrance Or Enhancement?, David L. Peeler Jr.

Theses and Dissertations

This thesis investigated the influence, if any, of background graphics on the decision making process. Specifically the hypotheses tested the affect of background graphics on a decision makers accuracy and confidence. A literature review revealed an abundance of graphic research but little reference to the use of background graphics. Using guidelines previously created for high integrity graphics, a timed 2 x 2 factorial experimental design was developed to compare the responses to both traditional graphics and those treated with background graphics. One hundred forty-seven subjects, all employees of the United States Air Force or defense contractors were involved in the …

An Exploration Of Environmental Technology Transition From The Laboratory To The Field, Michael A. Greiner

Theses and Dissertations

Environmental policy, social factors, individual behavior, and environmental technologies are key factors in improving the current condition of the environment. The Department of Defense (DoD) is not immune to these aspects, as its actions have and will continue to impact the environment in which they conduct operations. The objective of this research is to analyze the environmental technology aspect of improving environmental conditions. Of particular interest, what barriers and bridges are encountered when an Air Force laboratory transitions environmental technologies to an end-user: operational field organization or major weapon system. The research employs a case study methodology to analyze five …

An Exploratory Study Of The Benefits Received By Wright Laboratory (Wl) From Technology Transfer Activities, Clinton J. Braun

Theses and Dissertations

The allocation of resources should be a rational decision making process where alternatives can be compared based on their estimated costs and benefits to the organization. In order to justify technology transfer activities, a sound methodology must be developed that will document the benefits derived from transfer activities. The risks or uncertainties associated with those benefits must also be estimated and analyzed. By detailing the costs, benefits, and uncertainties associated with technology transfer activities, decision makers will have a logical framework that can be used to determine the cost effectiveness of technology transfer. Leaders within the technology transfer arena are …

The Effects Of Managerial Succession On Air Force Members, Todd M. Young

Theses and Dissertations

Managerial succession causes disruption that impacts the incoming leader and members of the organization. Yet, surprisingly, there has been little research investigating the effects of succession on Air Force members. This study investigated four typical reactions to succession that seemed likely to be experienced by most employees. They included changes in: (1) member's attitudes about their job, (2) member's attitudes about their leader's behavior, (3) member's behavior on the job, and (4) the leader's behavior (as observed by the members). The mean responses of workers from organizations that had recently experienced succession (i.e., the supervisor has been in place for …

A Study Of The Educational, Experience, And Managerial Performance Requirements For Preparing Logistics Commanders, Thomas C. O'Malley

Theses and Dissertations

For some time, senior logistics leaders have been concerned that logisticians with experience in only one logistics function are unable to create and maintain an integrated, seamless logistics system. The Air Force has recently decided to consolidate logistics career fields at the Field Grade level to ensure future Logistics Group Commanders and other senior logisticians have the broad-base of skills, experience, and knowledge that is needed to effectively manage logistics activities. One important outcome of this consolidation is the adoption of a career progression model in which logistics officers will have experience in at least two logistics functions. Preparing officers …