Engineering Commons^™

Construction And Characterization Of An Extended Helicon Plasma Source, Russell Ford Jewett Jr.

Electrical and Computer Engineering ETDs

A new helicon source has been developed for plasma processing applications. The source is a modification of the traditional cylindrical helicon source design to rectangular geometry. In order to accomplish this, the antenna used for launching helicon waves is stretched in the direction perpendicular to the static magnetic field lines. This source was coupled to a long rectangular slab chamber which is used for the actual material processing. A static magnetic field of -200 Gauss peak strength, pointing out from the source into the diffusion region, was applied to facilitate helicon wave propagation. 13.56 MHz rf power was used to …

Guidelines For Establishing Irrigation Scheduling Policies, Charles M. Burt

BioResource and Agricultural Engineering

Successful on-farm irrigation scheduling requires that water delivery projects adopt a service concept, and that water deliveries be made with a high degree of reliability. An arranged delivery schedule and seasonal volumetric allocations are additional requirements. Until these conditions are met, attempts to implement modern on-farm irrigation scheduling techniques to maximize water use efficiency, and to maximize yields will be only partially successful.

Traffic Control For Automated Highway Systems: A Conceptual Framework, H.-S. Jacob Tsao

Faculty Publications

This paper proposes a conceptual framework for designing a traffic control scheme. It adopts a top-down approach to defining major design steps starting with high-level feature definition. With the desired features defined, the top-down approach then identifies and defines moves and related planning and movement functions that are required for supporting the desired features. The paper takes a systems view and identifies the safety issues regarding the movement coordination of the large number of vehicles on an Automated Highway System (AHS).

Linda Jacobson Interview Virtual Reality Evangelist, Loretta L. Lange

SWITCH

In the interview with Linda Jacobson, a Virtual Reality (VR) artist, Jacobson discusses the current and future state of VR technology’s role in the politics of the body, social identity, self, gender, class, and race. This article discusses the fact that barriers to access exist for a more diverse set of artists across race, class, and gender to engage with VR technology and the need to evolve the development platform, so artists can implement their ideas in a low-cost way. The author discusses Jaron Lanier’s ideas about using VR to explore other identities based on a theatrical model where the …

Optimal Inputs For System Identification, James M. Brown Ii

Theses and Dissertations

The derivation of the power spectral density of the optimal input for system identification is addressed in this research. Optimality is defined in information theoretic terms, with entropy quantifying the parameter information content of the input and output measurement sequences pertaining to a discrete time plant. The maximization of entropy is performed in the context of three different scenarios. First, the case in which the average output power of the plant is constrained is considered. Second, input average power is constrained. Finally, the optimization is carried out unconstrained, but with penalties applied to both the input and output powers. Although …

Full Envelope Control Of Nonlinear Plants With Parameter Uncertainty By Fuzzy Controller Scheduling, Thomas J. Kobylarz

Theses and Dissertations

A full envelope controller synthesis technique is developed for multiple-input single-output (MISO) nonlinear systems with structured parameter uncertainty. The technique maximizes the controller's valid region of operation, while guaranteeing pre-specified transient performance. The resulting controller does not require on-line adaptation, estimation, prediction or model identification. Fuzzy Logic (FL) is used to smoothly schedule independently designed point controllers over the operational envelope and parameter space of the system's model. These point controllers are synthesized using techniques chosen by the designer, thus allowing an unprecedented amount of design freedom. By using established control theory for the point controllers, the resulting nonlinear dynamic …

Aggregating Organizational Performance Metrics Using The Analytic Hierarchy Process, Bret L. Indermill

Theses and Dissertations

Measurement provides factual information which is necessary for effective control of business processes. Implementing a Total Quality Management (TQM) philosophy is a common process in many organizations today. The United States Air Force is using the Malcolm Baldrige National Quality Award criteria to measure organizational performance in implementing the Quality Air Force (QAF) initiative. Unfortunately, the Baldrige-based unit self-assessment (USA) process is an inconsistent measure due to its subjectivity, and is also time consuming to use. This study determined that a new USA method based on the analytic hierarchy process (AHP) was not a significant improvement over the existing QAF-USA …

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 …

Assisting Defense Conversion Technology Transfer Efforts. A Case Study Of Ohio's Miami Valley, Marissa C. Salvador

Theses and Dissertations

Major changes in the geopolitical environment and the social and economic needs of the United States have resulted in resources being shifted away from national defense. Although the expected decrease in defense spending should not be harmful in macroeconomic terms, it can be devastating locally. To mitigate the effects of the drawdown, individual states and local communities must search for ways to bolster their local economies. One avenue that can be pursued to enhance future economic growth is the transferring of technologies to the commercial sector. Intermediary organizations have emerged to facilitate the process of technology transfer by serving as …

The Process Of Technology Transfer: A Case Study Of The National Aero-Space Plane Program, Brett T. Smith

Theses and Dissertations

Due to reduced funding levels and increased pressure towards cooperation with industry, government research and development (R&D) organizations are becoming increasingly involved in the transfer of technology to the commercial sector. However, the process of technology transfer is complex, and transfer activities are being applied inconsistently across the Department of Defense. This research explores the approaches, processes and mechanisms to accomplish technology transfer. A comprehensive literature review documents many of the transfer concepts that have been proposed or are currently in use. A detailed case study then examines the technology transfer efforts of an advanced government research organization: the National …

A Comparison Of Consistent Versus Inconsistent Scheduling Rules In A Flow Shop Environment, Nicola Gismondi

Theses and Dissertations

A consistent scheduling rule is one which will ensure a job's priority (relative to all other job's) will remain constant as it moves from queue to queue in a production system. Previous research concerning flow shop priority scheduling rules focused on comparison of either consistent or inconsistent rules. Conversely, this study sought to provide additional insight by comprising consistent and inconsistent rules in a flow shop environment The Air Force uses both types of rules in maintenance and logistics scheduling. Time and money can be saved if the scheduling managers can better understand the effect of consistency on a system. …

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 …

A Performance Analysis Of The Air Force War Time Lean Logistics Pipeline, Craig S. Gaddis, David A. Haase

Theses and Dissertations

Lean Logistics is an innovative proposal designed to reduce the costs associated with reparable inventory management. The purpose of this thesis is to determine whether a wartime lean logistics pipeline can maintain acceptable aircraft availability rates in response to induced variations of order and ship time (OST) and flying hours for deployed forces. The Dyna-MEIRIC Version 6.4 simulation program was used to evaluate nine different factor-level combinations. The factors, OST and flying hours were varied at three different levels, low, medium, and high. Analysis of the results was accomplished using a two-factor ANOVA. The authors discovered that while increasing OST …

A Study Of The Structural Limitation Affecting Implementation Of The Government Performance And Results Act In Air Force Materiel Command Logistics, Darwina M. Liguori

Theses and Dissertations

This thesis provides an in-depth discussion of the Government Performance and Results Act (GPRA) of 1993. The GPRA is a new law that mandates strategic management be conducted in all federal government agencies. Soon all federal government agencies will be directed to comply with the requirements of the law and implement strategic management within their organizations. This study selected Air Force Materiel Command Headquarters (AFMC) logistics organizations and subordinate units as the test organization. Interviews were conducted with headquarters AFMC logistics and strategic planning personnel, as well as 88th Logistics Group personnel to evaluate several issues within their organization: (1) …

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 …

Tracking Air Force Pallets Using Rfid Technology: A Concept Study, Gary A. Gross

Theses and Dissertations

The lack of asset visibility experienced at Aerial Ports of Embarkation (APOEs) during Operation Desert Storm is a phenomenon that has occurred in every major conflict for the last 40 years. The costs associated with this lack of control directly relate to the combat readiness and capability of supported units. This study examined the possibility of installing a Radio Frequency Identification (RF-ID) system to track Department of Defense 463L pallets worldwide. Performance characteristics of commercially available RF-ID systems were summarized, and a conceptual Air Mobility Command (AMC) tracking system was presented. For purposes of concept study, Amtech Corporation's Intellitag RT …

Chp And Energy Conservation, Jim Mcgovern

Articles

The principles of the use of 'combined heat and power' (CHP) for the achievement of fuel energy conservation, minimisation of environmental impact and economic advantage are explained. A distinction is made between the two types of outputs: heat and work. It is argued that an efficiency value that is defined as the sum of the heat and work outputs divided by the energy of the fuel used is not very meaningful. An alternative, rational, efficiency is explained. It is concluded that CHP is an option to be considered where both heating and power are required, but is not a general …

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Building Services Engineering

No abstract provided.

Best Practices For Commercial Vehicle Monitoring Facilities Design, Nikiforos Stamatiadis, R. Clark Graves, John E. Schmidt

Kentucky Transportation Center Research Report

The great technological advances that were made over the last decade in monitoring traffic and the increased emphasis on highway safety for truck traffic have prompted a need to determine more effective ways to monitor and inspect truck traffic. Commercial Vehicle Monitoring (CVM) facilities provide the highway community with the means of supervising truck traffic. However, in an era with limited funds and space for roadway expansion. some consideration must be given to the types of facilities needed and the most efficient way to spend the available funds. Hence, a research study was initiated to determine the successful practices for …

Analysis Of Traffic Accident Data In Kentucky (1990- 1994), Kenneth R. Agent, Jerry G. Pigman

Kentucky Transportation Center Research Report

This report includes an analysis of traffic accident data in Kentucky for the years of 1990-1994. A primary objective of this study was to determine average accident statistics for Kentucky highways. Average and critical numbers and rates of accidents were calculated for various types of highways in rural and urban areas. These data can be used in Kentucky's procedure to identify locations that have abnormal rates or numbers of accidents.

Another objective of this study was to provide data which can be used in the preparation of the problem identification portion of Kentucky's Annual Highway Safety Plan. County and city …

Use Of Class Aa Concrete Modified With A High-Range Water Reducing Admixture In A Full-Depth Bridge Deck Slab Us 127, Lincoln County, David Q. Hunsucker, Michael D. Stone

Kentucky Transportation Center Research Report

Because it is desirable for bridge deck concrete to be strong and durable, the Kentucky Department of Highways chose to use a high-range water reducer to modify the properties of a conventional Class AA concrete mixture to be placed in a full-depth concrete bridge deck on US 127 in Lincoln County. A high-range water reducer is a chemical admixture that when added to low-to-normal slump concrete produces a high slump to flowing concrete. The higher slump enhances placement properties in areas of closely spaced and congested reinforcing steel such as that encountered in the corners of a skewed bridge structure. …

1995 Safety Belt Usage Survey And Evaluation Of Effectiveness In Kentucky, Kenneth R. Agent

Kentucky Transportation Center Research Report

The objective of this study was to establish 1995 safety belt and child safety seat usage rates in Kentucky. The 1995 survey documents the continuing results from enacting a statewide mandatory safety belt law in 1994. Data were collected at 100 sites and combined based on vehicle miles travelled for a given type of highway, rural or urban location, and county population category. Also included in this report is an analysis of accident records evaluating the effectiveness of safety belts.

The data show that the dramatic increase in usage rates after enactment of the statewide law has decreased a small …

A Pixel Scale Digital-To-Analog Converter Array For Liquid Crystal On Vlsi Displays, Gregory P. Nordin, S. T. Kowel, J. H. Kulick, R. G. Lindquist, P. J. Nasiatka, A. Thomsen

Faculty Publications

A pixel scale digital to analog converter and driver for liquid crystal (LC) cells is presented. The circuit is a compact CMOS logic gate that sums pulse density modulation (pdm) signals. Low pass filtering of the pdm signal is 'done by the LC material. The circuit is suitable to implement large arrays of converters as, for example, in display applications. It is applicable in LC on silicon displays where gray scale data are stored and converted at each pixel site. Advantages over the commonly used active matrix technology include the removal of all analog circuitry, no need for refresh, reduced …

A Model For Forecasting Pollution Prevention Life Cycle Costs For Air Force Major Weapon Systems, Mark E. Garner, Jennifer S. Kirchoffer

Theses and Dissertations

This research effort developed a modification to the HAZMAT program so that the program could provide the user with the capability to generate an estimate during the concept exploration and design phases for the total costs associated with hazardous materials usage in a major weapon system. Using the HAZMAT database, a spreadsheet was developed which projects a cost for a weapon system based on its total surface area and the number of aircraft to be produced by performing an analogy with a similar weapon system. The modification uses algorithm which are based on the hazardous material substances rather than processes …

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 …

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, …

An Evaluation Of Cost Metrics Used Within Aeronautical Systems Center, Kevin M. Byrne

Theses and Dissertations

Aeronautical Systems Center (ASC) system program offices rely on cost metrics to acquire information on program effectiveness and organizational improvement. This study was an attempt to determine the effectiveness of ASC’s cost metrics. The effectiveness of the metrics were determined by the desirability of the behaviors which are exhibited when individuals utilize the specific metrics. Using an expert panel to evaluate the metrics, data was collected using the Group Research Laboratory for Logistics located in Armstrong Laboratory at Wright Patterson AFB, OH. Metric diagnostic charts were utilized to arrange the data into a format which would provide effectiveness information. The …

An Empirical Investigation Of The Integrated Weapon System Management Concept Of Seamless Processes, Timothy H. Surabian

Theses and Dissertations

This research investigated the way four Air Force Materiel Command (AFMC) single manager organizations operationalized the Integrated Weapon System Management (IWSM) concept of "seamless processes." In this thesis, the IWSM concept of "seamless processes" refers to the degree of integration between acquisition and sustainment organizations. Four SPO organizations were involved in six case studies. This research focused on the way "seamless processes" affect the shifting of the organizational "center of gravity" within or between single manager organizations. An interview questionnaire was administered to 13 Product Center managers and 6 Logistics Center managers. The interview questions focused on IWSM in general, …

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 …

A Review Of Fighter Aircraft Capability For Smart Bombs, David R. King

Theses and Dissertations

This study examined potential alternatives and decision criteria for inclusion in a Cost and Operational Effectiveness Analysis to recommend an alternative for addressing existing DOD multi-role fighter capability to employ inertially guided smart bombs. A survey of literature and interviews with expens were used to collect required information. An Analytical Hierarchy Process (MIP) decision model was developed for two feasible alternatives and four relevant decision criteriL The two feasible alternatives included either developing the BRU-53 smart bomb rack, or modifying F-15E conformal fuel tanks with additional smart interface wiring. Data on quantitative and qualitative decision criteria were collected to evaluate …