Digital Commons Network^™

An Investigation Into Aircraft Availability, Michael S. Kapitzke

Theses and Dissertations

The Air Force currently uses an expected value model in the Aircraft Availability Model (AAM) to calculate aircraft availability. However, even with the application of Lean Logistics, the failure-demand rate and the depot repair time are not fixed and the mean value is still used in the model. This research looks at the effect of the magnitude of the variance of the distributions of failure-demand rate and depot repair time. Also, this research evaluates the effect of variable mean failure-demand rates on the variability of aircraft availability. A simulation model was developed which applied the variable failure-demand rates and depot …

A Comparative Study Of Linear And Nonlinear Estimate At Completion Methods, Todd D. Nystrom

Theses and Dissertations

Controlling costs in the acquisition of new defense systems is a major challenge in today's environment of declining budgets and rapidly changing technology. One of the challenges faced by program managers and cost analysts is selecting the most appropriate Estimate at Completion (EAC) method for their program. This study compares the performance of the popular index-based EAC methods with several newer nonlinear, regression based EAC methods to determine whether the complex nonlinear methods perform better than the simpler index-based methods. In addition, the sensitivity of the results to stage of contract completion, system type, program phase, contract type, Department of …

A Comparative Evaluation Of Voice Versus Keypad Input For Manipulating Electronic Technical Data For Flight Line Maintenance Technicians, David A. Chapman, James R. Simmons

Theses and Dissertations

Interactive Electronic Technical Manuals will soon become a requirement for aircraft maintenance technicians. An important aspect in their development is the selection of an input device that will enhance, rather than impede, technician performance. The purpose of this thesis was to evaluate two types of input devices that can he used: a voice recognition input and a keypad input. Studies to date have evaluated the superiority of digital data over paper data, and advantages of using a Head Mounted Display Device over a flat screen laptop computer. No research has evaluated the input device. An experiment was conducted to determine …

Assessing The Impacts Of Lean Logistics Infrastructures On Strategic Airlift Capability, Russ C. Major

Theses and Dissertations

The purpose of this research was to compare two lean logistics infrastructures to See which one would provide better support for the C-5 aircraft. The level of support was defined as the average number of mission capable parts (MICAPs) created by system operation. One infrastructure had the central storage facility (CSF) located at the depot and the other had a geographically separate CSF. A computer simulation model developed by the Air Force Logistics Management Agency was run for a period of twelve years and the average number of MICAPs for each system was collected. The data was then analyzed using …

A Study Of Cumulative Trauma Disorders Of The Upper Extremities And Occupation In Wright-Patterson Adir Force Base Civilian Personnel, Scott T. Hillstead

Theses and Dissertations

This study utilized a case-control methodology to describe and analyze the 115 cases of occupational illnesses reported by civilian employees of Wright-Patterson Air Force Base (AFB) between 1990 and 1995. Determining if a statistically significant association existed between age and duration of employment risk factors and cumulative trauma disorders (CTDs) was a primary objective. The frequency of CTDs among the various organizations at Wright-Patterson AFB are also described. The research could not prove the existence of a significant association for the 44 subjects and 176 controls matched on occupational group. However, the demographic and other descriptive results may form a …

Just In Time Manufacturing: A Migration From Materials Requirements Planning, Scott A. Koehler

Theses and Dissertations

Manufacturing planning and control systems play an important role in an organization's effectiveness. Over the past twenty to thirty years, U.S. manufacturing companies have faced increasing competition for market share from Japanese and other Pacific rim countries. This thesis will investigate the evolutionary path followed by manufacturing companies that have implemented various manufacturing planning and control systems. Specifically, Materials Requirements Planning (MRP) and Just In Time (JIT) production will be analyzed. MRP is a means of convening demand for the final product into a requirements schedule for the various components comprising that product. The JIT philosophy calls for continuously improving …

Calibration Of The Software Life Cycle Model (Slim) To The Space And Missile Systems Center (Smc) Software Database (Swdb), Robert K. Kressin

Theses and Dissertations

Several sophisticated Department of Defense (DOD) weapon and space systems depend on a variety of mission-critical computer software applications. Because of the increasing costs to develop these applications, and today's austere defense budget, accurately estimating the costs to develop software is gaining a great deal of attention within the DOD. Unfortunately, software cost estimation models have been encountering difficulties in accurately estimating the costs of software development. However, research has shown that calibrating one's software cost estimation model can improve the predictive capability of that model. As such, this study focused on calibrating the SLIM cost model to sets of …

A Preliminary Analysis Of The Theoretical Parameters Of Organizational Learning, Jeffery D. Loyd

Theses and Dissertations

The goal of this research was to develop an instrument capable of measuring the theoretical parameters of organizational learning that could be used as a diagnostic tool to measure an organization's learning potential. This goal was accomplished by developing a pilot questionnaire based on 27 potential learning parameters. The potential parameters of learning were extracted from the literature. A scale of behavioral statements was developed for each potential parameter. The pilot questionnaire was completed by 108 Air Force personnel in Air Force Institute of Technology (AFIT) graduate education programs. The results confirmed 85% of the original scales. Ten refined scales …

Calibration Of The System Evaluation And Estimation Of Resources Software Estimation Model (Seer-Sem) For The Air Force Space And Missile Systems Center (Smc), Kolin D. Rathmann

Theses and Dissertations

This study examined whether calibration of the SEER-SEM impacted the effort estimates generated by the model for software developments- A historical database was provided by the Space and Missile System's Center Los Angeles, and used as the model's input data. The data was stratified into four usable platforms, military ground command and-control, military ground signal processing, military specification avionics, and military mobile. Each platform's data sets were split, the majority of points for calibration of the model, and the rest for model validation. The accuracy of SEER to this particular data set is limited, yet the model did respond to …

Calibration Of The Software Architecture Sizing And Estimation Tool (Saset), Carl D. Vegas

Theses and Dissertations

This study attempted to analyze the effect of calibration on the performance of the SASET computer software cost estimating model. Data used for input into the model were drawn from the most current USAF SMC Software Database (SWDB). Once all the records to be used for analysis were identified, the DBMS-Calibration tool (which is part of SASET) was used to perform regression analysis on the relationship between program size (measured in SLOC) and the effort required to develop the program (measured in man-months). Productivity information reported from this tool was then input into equations used to calculate the Productivity Calibration …

Air Force Materiel Command (Afmc) Modeling, Simulation, And Analysis (Ms&A) Interactive Database, Timothy J. Wagner

Theses and Dissertations

This study develops a high level, unifying taxonomy for Modeling, Simulation, and Analysis (MS&A) products for the Air Force Materiel Command (AFMC). AFMC is concerned that limited resources are being expended on duplicative MS&A efforts. No mechanism exists that would confirm or deny this concern, so it was suggested that a database could be developed to catalog and track AFMC's MS&A inventory. First, it was necessary to determine the information that a decision maker needs to select a suitable MS&A product. Potential traits and characteristics were identified through review of current regulatory guidance, interviews with MS&A users, and a study …

An Evaluation Of The Appropriateness Of The Defense Logistics Agency's Model Requirements Model, Harry A. Berry, Edward E. Tatge

Theses and Dissertations

This thesis discusses the appropriateness of the Defense Logistics Agency's (DLA) requirements model in managing consumable support for Air Force peculiar items. Currently, DLA uses a lot sizing technique referred to as the classic Economic Order Quantity, (EOQ) model. One of the key assumptions of this model is that demand is constant and continuous. Yet with Air Force bases using a lot sizing technique to place their demands for consumable items to DLA, it is apparent that the demand pattern that DLA faces, at least for Air Force peculiar items, is not constant and continuous. This study looks at the …

The Impact Of Priority Consistency On The Performance Of A Job Shop, Kenneth W. Bailey

Theses and Dissertations

This study introduces the construct of consistency to production operations management research. As a job passes through a job shop, its priority may or may not remain consistent relative to other jobs in the system. A new classification of priority rules is introduced. Consistent priority rules maintain a jobs priority relative to other jobs throughout the system. Inconsistent priority rules allow a job's relative priority to change as it moves through the system. This study is an initial investigation into the effect of consistency on performance. A simulation experiment was conducted using a full two- factorial repeated measures design with …

Aligning Demand For Spare Parts With Their Underlying Failure Mode, Steven D. Kephart, Richard C. Roberts

Theses and Dissertations

Current Air Force demand forecasting systems, DO41 and REALM, assume reparable demand is solely flying hour driven. The purpose of this study is to evaluate the relationship between demands, flying hours, and number of sorties at the work unit code level and improve reparable demand forecasting. A three phase methodology is used to analyze the demand, flying hour, and sortie relationship. The first phase uses multiple regression to determine a relationship at various work unit code levels. Multiple regression provides limited correlation between demands, flying hours, and sorties. The second phase uses Poisson regression to evaluate the integer, count nature …

The Effect Of Consolidating Two-Level Reparable Inventories On Aggregate Inventory Requirements And Mission Capability, Glenn R. Barney

Theses and Dissertations

One of the proposals of Lean Logistics is the relocation of many inventory assets to Intermediate Supply Points (ISPs). This research investigates the effect of consolidating Two Level Maintenance designated reparable asset inventories. The effects of interest are the potential reduction in aggregate inventory requirement and resulting savings and the effect of delayed issue of the assets on mission capability. The metric selected to measure the effect on mission capability for this study is the Not Mission Capable-Supply (NMCS) rate. A spreadsheet analysis of world-wide Two-Level Maintenance designated reparable asset demands over the study period is used to determine the …

The Implementation Of Federal Government Policy In The Reuse Planning Of Military Installations: A Case Study Of Gentile Air Force Station, John L. Hoover

Theses and Dissertations

Local communities affected by a base closure are uncertain as to their future and look to the federal government for guidance and economic assistance in rebuilding their local economy. The local communities want to close the base with as little federal government interference as possible and convert the base to civilian use with as much federal financial assistance as possible. During 1993-1994 two Air Force Institute of Technology research teams began longitudinal case studies of the base closure and rescue process at Gentile Air Force Station, Ohio to determine the effectiveness of the federal government's current approach. These research teams …

A Comparison Of The Standard Base Supply System And The Distribution And Repair In Variable Environments Models In Determining A Depot Working Level, Joseph M. Ferris

Theses and Dissertations

The Air Force has adopted a philosophy of logistics operations directed toward improving the products, costs, and responsiveness of the Air Force's reparable pipeline. The philosophy was termed Lean Logistics. This research addressed one problem created through the implementation of Lean Logistics. The problem was determining a depot Working LeveL The Air Force Materiel Command needed to determine an appropriate method to use when determining the depot Working Level. To help determine the appropriate method, this research compared the Standard Base Supply System (SBSS) and the Distribution and Repair In Variable Environments (DRIVE) model. Both models were utilized in two …

A Study Of The Factors Associated With Successful Technology Transfer And Their Applicability To Air Force Technology Transfers, James B. Rose

Theses and Dissertations

Although the United States is a world leader in scientific research, it lags behind some economic powers in the application of technologies. As quality and manufacturing excellence were critical to US competitiveness in the l98Os, so is commercializing technologies in the 199Os. With billion dollar budgets and exceptional scientific talent, the potential for fruitful technology transfer is abundant. By definition, federal-to-commercial technology transfer is the ability to leverage national investments in technology beyond their traditional customer base. The technology can be physical devices, processes, knowledge, or proprietary information. Unfortunately, and despite exhaustive legislative efforts, US industry has fallen behind its …

Pharmaceutical Inventory Forecasting At The Wright-Patterson Medical Center, Patrick J. Reymann

Theses and Dissertations

This research was conducted to determine the accuracy of statistical forecasting techniques forecasting the inventory of pharmaceutical items. Because pharmaceutical items are subject to a degree of seasonality of demand, the Director of Medical Logistics at the Wright-Patterson Medical Center believed that the use of such techniques may provide a more accurate forecast for the items stocked by the Outpatient Pharmacy. In addition to the technique used by the Outpatient Pharmacy (the 12 month simple moving average) three statistical forecasting methods were employed: the 6 month simple moving average, simple exponential smoothing, and the Winter's exponential smoothing. These techniques were …

Optical Characterization Of Indium Arsenide Antimonide Semiconductors Grown By Molecular Beam Epitaxy, Michael A. Marciniak

Theses and Dissertations

The material parameters and crystalline quality of undoped, MBE-grown InAs_1-xSb_x nearly lattice-matched to (100) GaSb (-0.617% ≤ Δ a-a ≤ +0.708%) similar to material used for mid-infrared semiconductor lasers were determined by optical characterization. Absorption measurements at temperatures between 6-295 K determined the energy gap and wavelength-dependent absorption coefficient for each sample. The compositional dependence of the energy gap was anomalous when compared to previously reported data, suggesting phase separation existed in the material. The samples were also studied by temperature- and excitation-dependent photoluminescence (PL), which, for the majority of cases, showed only a single band-edge peak, …

Student And Faculty Perceptions Of A Notebook Computer-Based Instructional System: A Case Study, Paula R. Cooke

Theses and Dissertations

Notebook computers are becoming an increasingly prevalent, and sometimes mandatory, accessory in college education. They and other new computer-assisted educational tools can increase dramatically the efficiency of traditional methods of instructional delivery and can provide the technological basis for new innovations in teaching strategy. However, as with any paradigm shift, the changeover in teaching and learning methods is difficult, expensive, and a disruption to the "status quo."

The object of this study was a four year polytechnic institution that recently implemented a mandatory notebook computer program for all students. The purpose of this study was to discover the perceptions of …

Teacher Attitude And Curricular Change: The Journey Of Three Elementary Teachers, Marla Mastin

Theses and Dissertations

This qualitative* study focuses on the influence of three elementary teachers' attitudes on a mathematics curricular change. The study takes place in a small school district in southeastern New York. A collection of data was facilitated by observations, interviews, and journal entries for a period of nine months.

The analysis of the data resulted in six themes: (a) The three participants saw the rationale for the curricular change as suspect; (b) they also saw selected components of the new program as problematic; (c) two of the pai'ticipants felt that as they became more involved in the new mathematics curriculum their …

Nonlinear Geometric And Material Behavior Of Composite Shells With Large Strains, Scott A. Schimmels

Theses and Dissertations

A two-dimensional, geometrically and materially nonlinear shell theory applicable to arbitrary geometries described by orthogonal curvilinear coordinates and encompassing large displacements, moderate rotations for large strain situations has been developed. Additionally, the theory includes Jacobian transformation matrices, based upon displacement parameters, for the Cauchy - 2nd Piola-Kirchhoff stress-state and the Cauchy (Almansi) - Green strain-state transformations, and a layered material approach is included for the elastoplastic analysis to allow for variation of plasticity through-the-thickness. Doubly curved 20, 28, and 36 degree-of-freedom finite elements are defined based on specialization of the theory to spherical coordinates. The computer program includes algorithms for …

Designing A Voice User Interface For A Fuzzy Expert System Tool (Fest), Scott Michael Josephson

Theses and Dissertations

This thesis deals with the design and implementation of a Voice User Interface for the Fuzzy Expert System Tool known as FEST. The interface has voice input and voice output capabilities which allows for a closer communication between the end-user and the computer. The thesis discusses the grammar language, user training, and specific library routines used for the voice input part of the interface. Also the creation and usage of digitized speech is discussed for the voice output part of the interface.

Gender Specific Rhetoric: A Look At Today, Mary Helen Richer

Theses and Dissertations

Gender impacts every part of life. From the moment a baby is bom, that child is placed in a gender categoiy. As one grows, these categories define how the person should act as well as how they should speak. These stereotypes become such a part o f an individual that often they are seen as an innate or biological part o f women and men, but this is not the case. These stereotypes can be broken and many are, particularly by women who feel it necessaiy to conform to the male standard to get ahead in business. Therefore, it is …

Entrepreneurship Education: Beliefs And Experiences Of North Dakota Vocational Secondary School Teachers, Dianne Potter Wood

Theses and Dissertations

The purpose of this study was to investigate North Dakota secondary school teachers’ beliefs about and experiences with teaching entrepreneurship education to secondary students. The study attempted to describe teachers’ perceptions of their experiences teaching entrepreneurship education to secondary school students.

This study included North Dakota secondary school teachers who had taught at least one stand-alone course in entrepreneurship education during the 1994-95 school year. Data were collected through a mail survey instrument and through personal interviews. The data from the 22 usable survey instruments were analyzed using descriptive statistics. A card-sort technique and open-ended questions were used during ten …

A Resource Guide For Interdisciplinary Teams In Middle Schools, Claudia Albrecht Tomanek

Theses and Dissertations

This dissertation documents the development of a resource guide to offer members of interdisciplinary middle school teams assistance in performing teaching and group process functions. The guide addressed critical issues in implementing interdisciplinary teaming, team practices, and benefits of teaching teams for students and colleagues. Group process techniques included communication, decision making, and conflict resolution skills. Day-to-day function sections included job descriptions/teaming roles, parent involvement, student motivation, cooperative learning, curriculum integration, professional staff development, and evaluation.

Materials for this guide were drawn from current sources in the middle school field and assembled in a format that might be used for …

Screening In Classrooms For Nonverbal Learning Disabilities: Validation Of An Instrument, Robert Stewart Scott

Theses and Dissertations

The purpose of the study was to determine the validity and reliability of a nonverbal learning disability evaluation (NLDE) scale using an instrument intended to screen for nonverbal learning disabilities in classroom settings. Scholars believe that there are at least four distinct subtypes of learning disabilities, each with its own characteristics and interventions. Validity was examined via an ANOVA, discriminant functions analysis, and factor analysis. Reliability was examined via use of Cronbach's alpha ( a = .93).

The sampled populations were special education and regular education teachers in North Dakota and 61 of the students they served. The 43 LD …

Improving Aspen/Sp Computer Model Of Great Plains Coal Gasifiers, Md. Moazzem Hossain

Theses and Dissertations

The Great Plains Gasification Plant located in Beulah, North Dakota, operated by the Dakota Gasification Company (DGC) is the only commercial production plant in the United States making synthetic natural gas (SNG) from coal. DGC operates 14 Lurgi gasifiers to produce 158 million ft3/day of SNG from 17,000 tons of North Dakota lignite coal. As the first step in constructing a model of the entire plant to control its operation and optimize the economic performance, an ASPEN/SP computer model (called RGAS) of a Lurgi gasifier was developed with the combined effort of several researchers. RGAS will predict the impact of …

Implementation Of Effective Schools Correlates By Bureau Of Indian Affairs Elementary Pilot Schools: Staff Perceptions And Achievement Scores, Viola Theresa Champagne Lafontaine

Theses and Dissertations

This study examined whether or not the effective schools efforts initiated by the Bureau of Indian Affairs affected student academic achievement in the pilot schools used for the BIA's effective schools improvement efforts. Data were obtained about ten effective schools correlates from ten BIA elementary schools in the BIA's first-year efforts to implement the effective schools improvement process.

An effective schools questionnaire was developed and used to obtain the perceptions of the professional staff regarding the implementation of the effective schools correlates in the ten schools located throughout the United States. Standardized test scores from 1988 and 1992 were collected …