Digital Commons Network^™

The Effects Of Changing Force Structure On Thunder Output, Michael R. Farmer

Theses and Dissertations

In today's reduction of America's national defense, campaign level models are being used more in the development of force structure. The effects of drawdown are of significant interest to those at the highest levels of authority. Campaign models can bring those high ranking officials the answers they seek with high confidence. THUNDER is a campaign model used frequently by the United States Air Force and many of its contractors. The effects of changing the force structure within THUNDER require modifying variables before executing a new experimental run. Changes in such issues as force structure cannot be immediately addressed. Response Surface …

Modeling Mobility Engineering In A Theater Level Combat Model, Brian K. Hobson

Theses and Dissertations

This thesis describes the development of a methodology to model theater-level mobility engineering assets in the Joint Staff's Joint Warfare Analysis Experimental Prototype (JWAEP) and to quantify the joint and Army doctrine that guides the task organization of engineers for combat and which quantifies engineer mobility effects in combat. The methodology incorporates theater-level mobility engineering assets into the JWAEP by using Mission, Enemy, Troops available, Terrain, and Time (MET-T principles which reflect joint and Army doctrine, and combines them with the existing basic concepts in other theater-level models. Additional aspects of the problem include determining the manmade and natural obstacles' …

The Evolution Of Aphis Two Gas Cartridges, Craig A. Ramey, Edward W. Schafer Jr

Vertebrate Pest Conference Proceedings: 17th (1996)

The U.S. Department of Agriculture, Animal and Plant Health Inspection Service (APHIS) has two federal (Section 3) vertebrate pesticide registrations with the U.S. Environmental Protection Agency (EPA) for gas cartridges to control damage to American agricultural resources and reduce threats to public health and safety. The gas cartridges are pyro-fumigant devices that produce primarily carbon monoxide when ignited. In sealed burrows or dens, carbon monoxide is highly toxic when inhaled, leading to tissue hypoxia. Carbon monoxide is recommended by the American Veterinary Medicine Association's panel for euthanatizing animals because it quickly induces unconsciousness without pain and with minimal discernible discomfort. …

Transient And Dynamic Average-Value Modeling Of Synchronous Machine Fed Load-Commutated Converters, Keith Corzine, S. D. Sudhoff, H. J. Hegner, D. E. Delisle

Electrical and Computer Engineering Faculty Research & Creative Works

A new average-value model of a synchronous machine fed load-commutated converter is set forth in which the stator dynamics are combined with the DC link dynamics. This model is shown to he extremely accurate in predicting system transients and in predicting frequency-domain characteristics such as the impedance looking into the synchronous machine fed load-commutated converter. The model is verified against a detailed computer simulation and against a hardware test system, thus providing a three-way comparison. The proposed model is shown to be much more accurate than models in which the stator dynamics are neglected

Surface-Related Breakdown In Silicon: Imaging Of Current Filaments In Long P+-N--N+ Structures, B. J. Hankla, P. F. Williams, G. A. Frecks, F. E. Peterkin

P. F. (Paul Frazer) Williams Publications

We present Schlieren images which show the existence and evolution of current filaments during the very early stages of surface-related breakdown inside 1 cm silicon p⁺-n^--n⁺ structures. These images confirm our previous finding that breakdown occurs in the silicon rather than in the ambient, and suggest that a streamerlike mechanism may be responsible.

Development And Testing Of A New Optimum Design Code For Hypersonic Wind Tunnel Nozzles, Including Boundary Layer, Turbulence, And Real Gas Effects, Ralph C. Tolle

Theses and Dissertations

A robust and efficient optimization code is developed and validated. The code is used to redesign an existing Mach 12 wind tunnel nozzle and utilizes response surface methodology (RSM) techniques. Explicit, globally second-order, flux-difference-splitting algorithms are used to solve the Navier-Stokes (NS) and Parabolized Navier-Stokes (PNS) flow solvers incorporated into the optimizer code. Either the Baldwin-Lomax or the Yang-Shih k-s turbulence model may be employed in the optimization code. First, 2-D/axisymmetric NS and PNS flow solvers are developed/modified and account for perfect gas/nonequilibrium chemically reacting flows. All solvers are validated against Computational Fluid Dynamics (CFD) and experimental data. The optimization …

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 …

Bs News

Building Services Engineering

No abstract provided.

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, …

Politics, Engineering And Aridity—Sustainable Use Of Water In Arizona, Michael J. Brophy

Sustainable Use of the West's Water (Summer Conference, June 12-14)

26 pages (includes illustrations).

Determination Of The Temperature Coefficients Of Selected Material Constants Of Dilithium Tetraborate, Gregory S. Weaver

Theses and Dissertations

The first and second order temperature coefficients of the material constants c^E₁₁, c^E₁₂, c^E₄₄, c^E₆₆, and e¹⁵ of dilithium tetraborate (Li₂B₄O₇) have been measured over a temperature range of 20°C to 150°C. An improved resonator method was used to measure the fundamental zero mass loading antiresonant frequencies of selected pure-mode orientations of Li₂B₄O₇. Material constants extraction was performed using a linear least squares matrix method. The resulting material constant curves were fit with a third …

An Investigation Of The Speed And Power Limitations Of A Copper-Doped Gallium Arsenide Photoconductive Switch, David Clifton Stoudt

Electrical & Computer Engineering Theses & Dissertations

The processes of persistent photoconductivity followed by photo-quenching are demonstrated in copper-compensated, silicon-doped, semi-insulating gallium arsenide. These processes allow a switch to be developed that can be closed by the application of one laser pulse (λ = 1.06 μm) and opened by the application of a second laser pulse with a wavelength equal to twice that of the first laser (λ= 2.13 μm). Switch closure is primarily achieved by elevating electrons from a deep copper center which has been diffused into the material. The opening phase is a two-step process which relies initially on the absorption of the 2-μm laser …

Applications Of Statistical Process Control In Monitoring Aircrew Bombing Proficiency, Kirk G. Horton

Theses and Dissertations

The current tools used by squadron supervisors to monitor the bombing performance of aircrews flying F-111E aircraft are monthly reports that have little predictive capability. No real-time methodology exists for monitoring and predicting aircrew bombing performance and preventing bombing problems that might cause an individual to become unqualified. It has been suggested that Statistical process Control (SPC) can be applied to the bombing process to develop tools for managing the process, correcting problems, and improve the bombing performance of a squadron. This study investigates the application of SPC to the bombing process. It examines data taken from an F-111E Fighter …

Modeling Corps Artillery In A Theater Level Combat Model, Richard F. Bowyer

Theses and Dissertations

This thesis describes the development of a methodology to explicitly model corps artillery assets in the Joint Staff's Joint Stochastic Analysis Research (J-STOCHWAR) and to quantify Army doctrine that guides organization of artillery for combat. The methodology incorporates corps artillery into the J-STOCHWAR by using the five fundamentals for organizing for combat, which reflect Army doctrine, and combines them with basic concepts already used in existing theater-level models. Other aspects of the problem include determining the appropriate level of detail, identifying techniques to solve the problem, and verifying the results. The proposed decision analysis solution technique provides a feasible method …

An Analytical Framework For Assessing Future Force Structure Requirements Under Uncertainty, Michael L. Fredley

Theses and Dissertations

The objective of this research was to develop an analytical framework to assess future force structure requirements under the major uncertainties inherent in the post-Cold War era. Among the uncertainties are the frequency and nature of future threats to U.S. interests and the cost of maintaining, building, and demobilizing forces. The centerpiece of the methodology is a computer model which simulates the development of threats to U.S. interests and the actions the U.S. takes to protect those interests. From this simulation, the costs and risks associated with different policy alternatives can be estimated. The simulation is set within a broader …

Analysis Of A Current-Regulated Brushless Dc Drive, Keith Corzine, S. D. Sudhoff, H. J. Hegner

Electrical and Computer Engineering Faculty Research & Creative Works

Current-regulated brushless DC machines are used in a wide variety of applications including robotics, actuators, electric vehicles, and ship propulsion systems. When conducting system analysis of this or any other type of drive, average-value reduced-order models are invaluable since they provide a means of rapidly predicting the electromechanical dynamics and are readily linearized for control system synthesis. In this paper, a highly accurate average-value reduced-order model of a hysteresis current-regulated brushless DC drive is set forth. In so doing it is demonstrated that the drive exhibits five distinct operating modes. The physical cause of each of these modes is explained …

A Cultural Anthropological Overview Of The Niobara/Missouri National Scenic Riverways, Beth R. Ritter, Robert K. Hitchcock, Michelle L. Watson, Michele Voeltz, Thomas D. Thiessen, Oliver Froehling, Rebecca Hautzinger, Judith Campbell Miller, Michele Moray, Leonard R. Bruguier, Gloria Rial

United States Army Corps of Engineers, Omaha District

This document is a cultural anthropological overview and assessment of the Niobrara/Missouri National Scenic Riverways (NIMI). It represents the first formal planning step taken by the National Park service (NPS) to identify the different ethnic and religious groups of people that have historical and/or contemporary ties to the NIMI region. It primarily focuses on American Indian groups that used the NIMI region for various purposes in past historical times. The discussion of American Indian peoples emphasizes the three Federally-recognized tribes that reside in the NIMI region today, the Poncas, Santee Sioux, and Yankton sioux. Other groups that used the NIMI …

Total Ionizing Dose Effects In Mosfet Devices At 77 K, Kevin J. Daul

Theses and Dissertations

Total ionizing dose effects on thermal oxide and reoxidized nitrided oxide (RNO) MOSFET devices at 77 K were studied. The MOSFETs were immersed in liquid nitrogen and irradiated, using a ⁶⁰Co source, up to 1 Mrad(Si) at a dose rate of 107 rads(Si)-sec. Drain current-gate voltage characteristics were obtained and used to determine threshold voltage and transconductance. At 77 K the subthreshold slopes indicated no observed buildup of interface states in any of the transistors. Furthermore, all transistors experienced very little change in the transconductance. Typical negative shifts in threshold voltage as dose increased were observed in all of …

Artificially Intelligent Air Combat Simulation Agents, Daniel E. Gisselquist

Theses and Dissertations

The Advanced Research Projects Agency (ARPA), in an effort to improve military simulations, has proposed a standard for Distributed Interactive Simulation (DIS). This network protocol will allow dissimilar applications to communicate simulation information. In the field of air combat, this will allow pilots in remote simulators to fly in a common simulation. The success of this standard is dependent on applications being able to work within that standard, as well as a large variety of Computer Generated Forces (CGFs) to complement interactive forces. CGFs are needed to help simulate the large combat scenarios that can only occur in wartime. By …

The Effects Of An Integrated Space Support Node On Theater Air Combat, Paul J. Helt

Theses and Dissertations

The Air Force requires a methodology to assess alternative means for providing integrated space support data, collected from imagery space platforms, to enhance overall theater warfighting capability. This research examines imagery systems supporting the warning, surveillance, and weather missions, alternative concepts to integrate this imagery data, and models their influence on air-to-ground and limited ground-to-air combat in five potential theaters of operation. These theaters were Northeast Asia, Southeast Asia, Southeast Europe, the Caribbean, and Central America. Influence diagram decision analysis techniques were used to identify and quantify the key variables within the three space-based mission areas effecting air combat planning …

Improving The Performance Of Spiral Antennas By Using Passive Scatterers, Joseph S. Zaren

Theses and Dissertations

The purpose of this study was to explore the viability of improving the performance of cavity-backed antennas. Traditionally antenna cavities are filled with electromagnetic absorber to mitigate interference effects that would otherwise cause the antenna radiation pattern to vary widely at different frequencies. The approach used in this research was to replace the absorber with dielectric slabs, some of which contained arrays of dipoles. These dipole arrays were modeled as frequency selective surfaces using two periodic moment method based - computer programs and one transmission line program. A systematic study was performed that identified the effect of changing the dipole …

Survey And Implementation Of Commercial Manual Controllers For A Generic Telerobotics Architecture, Thomas E. Deeter

Theses and Dissertations

The purpose of this study is to determine an input device for the Air Force's generic telerobotics architecture for large aircraft maintenance and repair. One area of concern is the human to machine interface, more specifically, which manual controller should be used for the specified tasks in this architecture. We mailed a survey to 68 companies in order to compile a list of possible input devices that the telerobotics architecture could use. 32 companies responded which gave me enough data to generate a list that described the physical traits of the input devices. We then divided the required tasks into …

The Influence Of Seawalls On Beach Responses To Storms, Seasonal Transitions And Long-Term Erosion, John Marshall Hazelton

Civil & Environmental Engineering Theses & Dissertations

It has been argued that seawalls have a detrimental effect on the adjacent beaches. These effects may only be noticeable over a period of years or may be short-term effects associated with storms or with seasonal transitions of the beach. Many theories on beach and seawall interaction have been speculative and have lacked actual field or laboratory evidence for their basis.

This study uses four years of monthly and post-storm beach profile data to examine what influences the seawalls at Sandbridge, Virginia have on the adjacent beaches. Long-term effects of the seawalls are analyzed using fourteen years of profile data. …

Analysis Of The Jplan Exercise As An Experimental Learning Tool, Mark J. Lynch, Michael E. Washington

Theses and Dissertations

The purpose of this study is to develop an effective educational tool for the Combat Logistics course offered at the Air Force Institute of Technology. The current tool being used, the JPLAN Exercise, was identified as outdated in several areas. The research focused upon four investigative questions what makes an effective educational tool, should the existing exercise be revised or replaced, which logistics principles are essential for incorporation into the educational tool, and is the updated tool significantly different from the original. To answer these questions, we conducted an extensive literature review that focused on two areas. The first area …

An Analysis Of The Effect Of Personnel Drawdown Initiatives On Aircrew Experience, Keith L. Hedgepeth, Lennie J. Simpson

Theses and Dissertations

This study analyzes the effects of personnel reduction initiatives on aircrew experience levels of Air Force pilots and navigators. Four key measures of experience were defined, including total flight hours, flying hours in Primary Assigned Aircraft PAA, total hours at time of upgrade to instructor, and total PAA hours at time of upgrade to instructor. Three objectives were established for this study. These objectives measured the degree of change in overall aircrew experience for pilots and navigators in six major weapon systems, to determine if changes in aircrew experience varied by weapon system, and if changes in aircrew experience varied …

Transient Simulations And Modelling Of Semi-Insulating Gaas Photoconductive Switches, Prasun Kumar Raha

Electrical & Computer Engineering Theses & Dissertations

The primary objective of this thesis is to develop a one-dimensional transient simulator for Photoconductive Semiconductor Switches (PCSS) taking into consideration the material characteristics, the internal physical effects, and the external circuit. Simulations have been performed to study the device behavior at different voltage levels for copper-doped silicon-compensated GaAs material, though other materials could easily be simulated by changing the parameters. The model includes hole transport, and the results demonstrate the effect of hole injection, with and without recombination centers. In addition to developing a one-dimensional transient simulator, the role of various physical effects, such as the field-dependence of trapping …

Contrast Enhancement Of Medical Images Using Multiscale Edge Representation, Jian Lu, Dennis M. Healy Jr., John B. Weaver

Dartmouth Scholarship

Experience suggests the existence of a connection between the contrast of a gray-scale image and the gradient magnitude of intensity edges in the neighborhood where the contrast is measured. This observation motivates the development of edge-based contrast enhancement techniques. We present a simple and effective method for image contrast enhancement based on the multiscale edge representation of images. The contrast of an image can be enhanced simply by stretching or upscaling the multiscale gradient maxima of the image. This method offers flexibility to selectively enhance features of different sizes and ability to control noise magnification. We present some experimental results …

Design And Analysis Of A Mode B And Mode Jd Satellite Earth Station, Dennis J. Hance

Theses and Dissertations

This thesis focuses on the design, integration, and analysis of an amateur radio service mode B and mode JD satellite earth station. Preliminary designs were investigated to determine the optimum configuration for the earth station. Modern digital modems, cabling structures, an 80386-based computer system, satellite tracking software, transmission and reception antennas, preamplifiers, and sophisticated performance measurement technologies were integrated into a functioning earth station. Initially, component availability and station design dictated the selection and acquisition of the requisite station equipment, integration of the transmitter, receiver preamplifiers, antennas, and computer equipment followed. Preliminary testing of the various components in the integration …

An Integrated Approach To Implement Iso 9000 Series Standards To United States Manufacturing Industry, Jatin N. Amin

Theses

Implementation of ISO 9000 series quality system standards to the U.S. manufacturing industry is discussed by developing a generic model for implementation. In recent past, quality became a prime performance issue to formulate strategy to improve market share and profit for U.S. manufacturing industry. Many companies seeks for ISO 9000 registration. Manufacturing industry and other industries as well, are facing numerous problems in implementing ISO 9000 quality system standards. At present, about 400 U.S. companies have gained certification under this standard.

In this work an attempt has been made, to highlight problems which are most likely to be critical to …

An Aerodynamic And Static-Stability Analysis Of The Hypersonic Applied Research Technology (Hart) Missile, Kenneth J. Moran

Theses and Dissertations

The flow about the complete Hypersonic Applied Research Technology (HART) missile is simulated for inviscid, laminar, and turbulent conditions and Mach numbers from 2 to 6. An explicit, second-order-accurate, flux-difference-splitting, algorithm is implemented and employed to solve the Navier-Stokes equations. The formulation models turbulence with the zero-equation, Baldwin-Lomax turbulence model, accounting for pressure-gradient and compressibility effects. The equations are solved using a finite-volume methodology. In the first part of the study, numerical experiments are performed using an infinitely thin-fin approximation. The aerodynamic and static-stability characteristics are investigated to determine if conventional supersonic missile configurations can be flown at Mach numbers …