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Air Force Institute of Technology

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Buying A Better Air Force, Jenny O. Herald Mar 2006

Buying A Better Air Force, Jenny O. Herald

Theses and Dissertations

The purpose of this study was twofold: (1) to capture the United States Government's revealed preference for air superiority using the hedonic pricing approach (HPA), and (2) to compare the characteristics of U.S. Air Force (USAF) fighter aircraft with those of the former Soviet Union to evaluate the effectiveness of the USAF fleet. The resulting analysis showed that the U.S. Government is paying for physical and performance characteristics such as engine thrust, service ceiling, range, and large-scale integrated circuit technology. However, evidence suggests that the government is not paying to have a relative advantage over the enemy based on the …


Backward Amplification And Beam Cleanup Of A Raman Fiber Laser Oscillator Using A Multi-Mode Graded Index Fiber Amplifier, Jesse D. S. Morgan Iii Mar 2006

Backward Amplification And Beam Cleanup Of A Raman Fiber Laser Oscillator Using A Multi-Mode Graded Index Fiber Amplifier, Jesse D. S. Morgan Iii

Theses and Dissertations

This thesis tested a CW fiber-based Raman amplifier implemented in a backward pumped geometry. To create a seed for the amplifier, a CW Nd:YAG laser operating at 1.064µm was used to pump a 50µm multimode graded index fiber using fiber Bragg gratings to create a Raman Fiber Laser (RFL) Oscillator with a Stokes beam at 1.116µm. The Stokes beam was then used to seed two lengths, 5.3km and 2.5km, of 50µm multimode graded index fiber. The fiber amplifier was pumped by a second CW Nd:YAG laser in the backward geometry. Spectral data taken for both fibers indicated that the backward …


Optical Characterization Of Thick Growth Orientation-Patterned Gallium Arsenide, Joshua W. Meyer Mar 2006

Optical Characterization Of Thick Growth Orientation-Patterned Gallium Arsenide, Joshua W. Meyer

Theses and Dissertations

Tunable laser sources in the mid-infrared (MIR) spectral range are required for several Air Force applications. Existing lasers with output in the near-infrared can be converted to more desirable MIR by using nonlinear effects. Orientation patterned gallium arsenide (OPGaAs) is a promising nonlinear conversion material because it has broad transparency and can be engineered for specific pump laser and output wavelengths using quasi-phase matching techniques. This research examines the optical quality of seven OPGaAs crystal samples and explores the design of an optical parametric oscillator (OPO) device. The Air Force Research Laboratory Electro-Optical Countermeasures Technology Branch obtained the samples from …


Investigation Of Copper Contamination And Corrosion Scale Mineralogy In Aging Drink Water Distributions Systems, Nadja F. Turek Mar 2006

Investigation Of Copper Contamination And Corrosion Scale Mineralogy In Aging Drink Water Distributions Systems, Nadja F. Turek

Theses and Dissertations

Research has shown higher levels of copper appear in drinking water conveyed through relatively new copper piping systems; older piping systems typically deliver lower copper levels in their drinking water. This research contributes field data from a real drinking water distribution system, providing a better understanding of this phenomenon, as it relates to treatment considerations and compliance with the Lead and Copper Rule. Copper pipes and copper levels were sampled from drinking water taps of 16 buildings with pipes ranging in age from less than 1 to 48 years. Water samples from each building were collected before and following a …


Comparison Of Climatological Optical Turbulence Profiles To Standard, Statistical And Numerical Models Using Heleeos, Liesebet E. Gravley Mar 2006

Comparison Of Climatological Optical Turbulence Profiles To Standard, Statistical And Numerical Models Using Heleeos, Liesebet E. Gravley

Theses and Dissertations

Optical turbulence within earth’s atmosphere plays a significant role in electromagnetic radiation propagation from a high energy laser. The index of refraction structure constant, Cn2, characterizes turbulent spatial fluctuations due to temperature gradients. These changes in the index of refraction affect the intensity of the laser wave front on its intended target. It is important to characterize this parameter throughout the atmosphere, the boundary layer and above, for its applications regarding the Airborne Laser (ABL) and the Advanced Tactical Laser (ATL). There are several ways to obtain values of optical turbulence, including standard and statistical models, physically-based numerical models, and …


Development Of A Three-Dimensional Air Blast Propagation Model Based Upon The Weighted Average Flux Method, Stephen R. Mchale Mar 2006

Development Of A Three-Dimensional Air Blast Propagation Model Based Upon The Weighted Average Flux Method, Stephen R. Mchale

Theses and Dissertations

Accurate numerical modeling of complex, multi-dimensional shock propagation is needed for many Department of Defense applications. A three-dimensional code, based upon E.F. Toro's weighted average flux (WAF) method has been developed, tested, and validated. Code development begins with the introduction and application of all techniques in a single dimension. First-order accuracy is achieved via Godunov's scheme using an exact Riemann solver. Adaptive techniques, which employ approximate solutions, are implemented to improve computational efficiency. The WAF method produces second-order accurate solutions, but introduces spurious oscillations near shocks and contact discontinuities. Total variation diminishing (TVD) flux and weight limiting schemes are added …


Modeling Study To Quantify The Benefits Of Groundwater Contaminant Source Remediation, David E. Wagner Mar 2006

Modeling Study To Quantify The Benefits Of Groundwater Contaminant Source Remediation, David E. Wagner

Theses and Dissertations

The purpose of this research was to quantify the benefits of groundwater contaminant source remediation by using a model to simulate how reduction of source mass was related to reduction of contaminant concentration at a receptor. This thesis sought to answer three research questions: (1) how are contaminant source mass reduction and reduction of mass flux leaving the source-zone related; (2) how can we quantify the effect of the important natural attenuation processes that act upon the dissolved contaminant as it travels from the source zone to downgradient receptors, and (3) under specified site conditions, what is the maximum contaminant …


Assessing The Potential For Improved Scramjet Performance Through Application Of Electromagnetic Flow Control, Martin F. Lindsey Mar 2006

Assessing The Potential For Improved Scramjet Performance Through Application Of Electromagnetic Flow Control, Martin F. Lindsey

Theses and Dissertations

Hypersonic flight using scramjet propulsion bridges the gap between turbojets and rockets. Recent efforts focus on magnetogasdynamic (MGD) flow control to mitigate the problems of high thermomechanical loads and low efficiencies associated with scramjets. This research is the first flight-scale, three-dimensional computational analysis of a realistic scramjet to assess how MGD flow control improves scramjet performance. Developing a quasi-one dimensional design tool culminated in the first open source scramjet geometry. This geometry was tested with the Air Force Research Laboratory's electromagnetic computational code. To increase fidelity, an algorithm was developed to incorporate thermochemistry, resulting in the only open-source model of …


Efficient And Accurate Computation Of Elastic Cross Sections In The Single-Level Breit-Wigner Resonance Region, Edward L. Hobbs Mar 2006

Efficient And Accurate Computation Of Elastic Cross Sections In The Single-Level Breit-Wigner Resonance Region, Edward L. Hobbs

Theses and Dissertations

The use of piecewise cubic Hermite polynomials to approximate resonance region cross sections provides a means to accomplish the same task with increased accuracy and fewer points that require exact cross section calculation. Once the derivative of the cross section formula is derived and the interpolating cubic is appropriately shifted and scaled for numerical stability, use of the piecewise cubic Hermite polynomial is easily inserted into computer codes that depend on cross section calculation in the resonance energy region.


Analysis And Simulation Of Hypervelocity Gouging Impacts, John D. Cinnamon Mar 2006

Analysis And Simulation Of Hypervelocity Gouging Impacts, John D. Cinnamon

Theses and Dissertations

In this work, a summary of past and present research efforts, as well as the theoretical foundation, of hypervelocity gouging is presented. As the Holloman AFB High Speed Test Track (HHSTT) sled's speed has increased to Mach 8.5, material interactions develops which causes "gouging" - this can result in catastrophic failure. A characterization of gouging, including a thermodynamic history, is developed from an examination of a gouged rail. An extensive study is performed that determines the specific material flow models for VascoMax 300 and 1080 steel. The models are validated utilizing several experimental tests which are successfully simulated using CTH …


The Effects Of Ability Homophily On Individual Performance, Michael J. Gray Mar 2006

The Effects Of Ability Homophily On Individual Performance, Michael J. Gray

Theses and Dissertations

Homophily is the sociological term for a principle that is easily observed and understood: similar people tend to associate with one another (or the well-known saying "Birds of a feather flock together"). Homophily creates divides among people with numerous demographic characteristics and causes people to surround themselves with others who are similar to themselves (McPherson et al., 2001). Race and ethnicity have the greatest influence on relationship choices followed by age, religion, education, occupation, and gender (McPherson et al., 2001). While studies of homophily of race and gender are quite common, few studies have examined homophily based on instrumental attributes …


Radiometric Analysis Of Daytime Satellite Detection, Katherine B. Lilevjen Mar 2006

Radiometric Analysis Of Daytime Satellite Detection, Katherine B. Lilevjen

Theses and Dissertations

A radiometric model for daylight satellite detection is developed and used to evaluate the effects of various parameters on signal-to-noise ratio (SNR). Detection of reflected sunlight from a low-earth orbit, diffuse, planar satellite by a single-pixel infrared photovoltaic detector is considered. Noise considered includes photon noise from the background and signal, as well as thermal noise. Parameters considered include atmospheric conditions, optical parameters, and detector parameters. The Phillips Laboratory Expert-assisted User System, an atmospheric modeling tool that employs the MODTRAN and FASCODE transmission codes, is used to model wavelength-dependent atmospheric transmission and background radiance. The SNR is found to increase …


Type Ii Quantum Computing Algorithm For Computational Fluid Dynamics, James A. Scoville Mar 2006

Type Ii Quantum Computing Algorithm For Computational Fluid Dynamics, James A. Scoville

Theses and Dissertations

An algorithm is presented to simulate fluid dynamics on a three qubit type II quantum computer: a lattice of small quantum computers that communicate classical information. The algorithm presented is called a three qubit factorized quantum lattice gas algorithm. It is modeled after classical lattice gas algorithms which move virtual particles along an imaginary lattice and change the particles’ momentums using collision rules when they meet at a lattice node. Instead of moving particles, the quantum algorithm presented here moves probabilities, which interact via a unitary collision operator. Probabilities are determined using ensemble measurement and are moved with classical communications …


Evaluation Of Chlorinated Solvent Removal Efficiency Among Three Wetland Plant Species: A Mesocom Study, Jun Yan Mar 2006

Evaluation Of Chlorinated Solvent Removal Efficiency Among Three Wetland Plant Species: A Mesocom Study, Jun Yan

Theses and Dissertations

Different species of plants need to be studied individually to compare the remediation efficiency of each species. This research will study three different wetland plants species and an unplanted control, under a laboratory setting. Each plant has a different characteristic favorable for chlorinated solvent degradation. Eleocharis erythropoda (Spike Rush) are plants with thin tube like leaves and large root mass. Carex comosa (Bearded Sedge) has broad leaves and Scirpus atrovirens (Green Bulrush) are broad leafed wetland plants with a long flowering stem during reproduction. PCE will be injected into the plant mesocosm and any possible PCE degradation will be observed. …


Comparative Analysis Of Biosurveillance Methodologies, David M. Kempisty Mar 2006

Comparative Analysis Of Biosurveillance Methodologies, David M. Kempisty

Theses and Dissertations

The purpose of this research is to compare two different biosurveillance methodologies: BioWatch and "A Hot Idea". BioWatch is fielded and operating in major US cities today. Air samples are collected on filter paper and analyzed for the presence of harmful biological agents. "A Hot Idea" is an evolving methodology using the human body's immune response to identify the onset of infection from a harmful pathogen. Detecting a temperature increase, using infrared thermographers, in a statistically significant portion of population would allow earlier identification of a biological release, accelerating initiation of response actions. A selected population including policemen, firemen, and …


Reducing Uncertainty In Effects-Based Operations, Wilburn B. Mclamb Mar 2006

Reducing Uncertainty In Effects-Based Operations, Wilburn B. Mclamb

Theses and Dissertations

Known as the fog of war, uncertainty has been prevalent in the conduct of military operations throughout human history. Intelligence collection efforts are tasked to reduce this uncertainty through the collection of information. Utilizing Shannon's entropy as a measure of the expected information gain due to an intelligence collection effort, a methodology is developed to prioritize and allocate intelligence assets in an efficient manner. Incorporated in this methodology are target priority and the requirement to reassess dynamic targets. The application area for the methodology is Effects-Based Operations. A generalized state model is developed to conduct adversary system-of-systems analysis. This model …


A Decision Model For Choosing Among Photovoltaic Technologies To Generate Electricity At Grid-Connected Air Force Facilities: A Value-Focused Approach, Mostyn O. Kellner Mar 2006

A Decision Model For Choosing Among Photovoltaic Technologies To Generate Electricity At Grid-Connected Air Force Facilities: A Value-Focused Approach, Mostyn O. Kellner

Theses and Dissertations

The United States is currently consuming fossil fuels faster than natural processes can replace them. Our nation's leaders recognize that a diverse energy portfolio including renewable energy is the key to maintaining our economy, security, and the environment. The federal government is by far the greatest energy consumer; thus, our nation's leaders have directed federal agencies to strive to increase the use of renewable energy at federal facilities. Solar electricity technologies, in the form of photovoltaics, have great potential in the renewable energy mix. Although a major strategy should be integrating photovoltaics into the design of new facilities, an important …


The Longitudinal Effect Of Self-Monitoring And Locus Of Control On Social Network Position In Friendship Networks, Gary J. Moore Mar 2006

The Longitudinal Effect Of Self-Monitoring And Locus Of Control On Social Network Position In Friendship Networks, Gary J. Moore

Theses and Dissertations

The purpose of this research was to identify how enduring personality characteristics predict a person's location in a network, locations which in turn affect outcomes such as performance. Specifically, this thesis examines how self-monitoring and locus of control influence an individual's location in a friendship social network over time. Hierarchical Linear Modeling (HLM) was used to analyze 28 groups of students and instructors at a military training course over six and one half weeks. Self-monitoring predicted betweenness centrality in five of six time periods while locus of control predicted betweenness centrality in three of six time periods. The moderation of …


A Graph Theoretic Analysis Of The Effects Of Organizational Structure On Employee Social Networks, John R. Hutzel Mar 2006

A Graph Theoretic Analysis Of The Effects Of Organizational Structure On Employee Social Networks, John R. Hutzel

Theses and Dissertations

A simulation technique was used to investigate the impacts of organizational structure on an organization's social network. By simulating personnel in an organization as vertices in a graph and the aging of the corporation as the aging of the same graph, the maturation of an organization was realized. The characteristic path length of the graph was measured after each year returning an optimistic average organizational distance. Results include the finding that, per this model, an organization's characteristic path length can drop over 50% in a 20 year period with consideration of edges of all strengths. Next a series of random …


Leadership In Groups: Social Networks And Perceptions Of Formal And Informal Leaders, Mitchell D. Stratton Mar 2006

Leadership In Groups: Social Networks And Perceptions Of Formal And Informal Leaders, Mitchell D. Stratton

Theses and Dissertations

The labors of organizational and behavioral science researchers have resulted in a literature robust in the study of leadership and social networks. Empirical examination of both topics has shown significant organizational outcomes, but breadth is lacking both within and between the disciplines. Studies of leadership have seen the preponderance of the effort focused on formal leaders, while most social network studies examine only one informal structure. Moreover, there exists a paucity of studies, which have sought to examine the interrelationships between leadership and social networks. In an effort to address these voids, this thesis investigated: 1) The concurrent existence of …


A Study Of Collapse Events In Ultraviolet Light Filaments Due To Transient Edge Effects, Paul L. Muller Mar 2006

A Study Of Collapse Events In Ultraviolet Light Filaments Due To Transient Edge Effects, Paul L. Muller

Theses and Dissertations

Intense, short light pulses can form filaments capable of propagating kilometers through the atmosphere. This is due to the nonlinear index of refraction of the atmosphere in response to the pulse's high intensity, which creates a self-focusing effect that further intensifies the pulse. This focusing is balanced by the formation of defocusing plasma by the pulse. A split-step propagation model was used to simulate the propagation of these pulses through the atmosphere and investigate the collapse of long ultraviolet pulses of 10-100 picoseconds in duration due to transient edge effects. The structures of individual collapse events in the pulse were …


Formal And Informal Work Group Relationships With Performance: A Moderation Model Using Social Network Analysis, Benjamin R. Knost Mar 2006

Formal And Informal Work Group Relationships With Performance: A Moderation Model Using Social Network Analysis, Benjamin R. Knost

Theses and Dissertations

Social networks have recently emerged in the management discipline as a unique way of studying individuals groups in organizations. While traditionally used in the analysis of un-bounded networks, applying social network analysis techniques to bounded work groups and organizational teams has become increasingly popular. Past research has established relationships between in-degree social network centrality and individual performance as well as social network density and overall group performance. This field study, conducted at a military training course, attempted to further refine this social network-performance relationship by modeling characteristics of both the formal and informal work group networks in relation to performance …


An Analysis Of Usaf Aircraft Noise And Hedonic Property Values, Melissa R. Johnson Mar 2006

An Analysis Of Usaf Aircraft Noise And Hedonic Property Values, Melissa R. Johnson

Theses and Dissertations

The primary purpose of the research was to evaluate whether there was a significant difference in housing values of those affected by the noise of USAF aircraft. The secondary purpose was to evaluate whether there was a significant difference in housing values located near USAF bases with and without aircraft noise and to evaluate whether type of aircraft changed the results created by the aircraft noise. This research effort found that homes located within the 65 dB DNL contour of US Air Force installations showed a significant negative impact due to the presence of aircraft noise when studied with the …


Evaluation Of Energy Costs And Error Performance Of Range-Aware Anchor-Free Localization Algorithms For Wireless Sensor Networks, Gustav Julio Jordt Mar 2006

Evaluation Of Energy Costs And Error Performance Of Range-Aware Anchor-Free Localization Algorithms For Wireless Sensor Networks, Gustav Julio Jordt

Theses and Dissertations

This research examines energy and error tradeoffs in Anchor-Free Range-Aware Wireless Sensor Network (WSN) Localization algorithms. A concurrent and an incremental algorithm (Anchor Free Localization (AFL) and Map Growing) are examined under varying network sizes, densities, deployments, and range errors. Despite current expectations, even the most expensive configurations do not expend significant battery life (at most 0.4%), implying little energy can be conserved during localization. Due to refinement, AFL is twice as accurate, using 6 times the communication. For both, node degree affects communication most. As degree increases, Map Growing communication increases, while AFL transmissions drop. Nodes with more neighbors …


Passive Multiple Beam Combination In Optical Fibers Via Stimulated Brillouin Scattering, Kirk C. Brown Mar 2006

Passive Multiple Beam Combination In Optical Fibers Via Stimulated Brillouin Scattering, Kirk C. Brown

Theses and Dissertations

Many active methods of scaling laser brightness have been demonstrated in recent years. The goal of this research was to demonstrate the feasibility of passively combining multiple laser beams using Stimulated Brillouin Scattering (SBS) in a long multimode optical fiber. This method of combination employed a “Gatling gun” fiber array that allowed several collimated beams to be focused by a lens into an optical fiber. The retroreflected Stokes beam is passed through the center of the beam combiner for analysis. In addition to experimental methodology and equipment used, the theoretical and historical background of SBS in optical fibers is provided. …


Singlet Delta Oxygen: A Quantitative Analysis Using Off-Axis Integrated-Cavity-Output-Spectroscopy (Icos), Jeffrey E. Gallagher Mar 2006

Singlet Delta Oxygen: A Quantitative Analysis Using Off-Axis Integrated-Cavity-Output-Spectroscopy (Icos), Jeffrey E. Gallagher

Theses and Dissertations

A new spectroscopic technique applicable to the detection of ultra-weak and for- bidden molecular transitions is presented. The method is based on off-axis integrated-cavity-output spectroscopy (ICOS). The primary goal for this research effort is to utilize the ICOS technique and demonstrate its ability to provide quantitative data of singlet delta oxygen. This thesis will focus on three areas of characterization to achieve this goal. First, the absolute line positions will be determined and compared to values derived from the most recent theory. Second, the integrated absorption cross-sections will be verified using Boltzmann analysis. Finally, pressure broadening coefficients will be determined …


Development Of A Multiple Beam Combiner Using Stimulated Raman Scattering In Multimode Fiber, Brian M. Flusche Mar 2006

Development Of A Multiple Beam Combiner Using Stimulated Raman Scattering In Multimode Fiber, Brian M. Flusche

Theses and Dissertations

Beam combination was demonstrated by splitting the beam from a diode pumped Q-switched Nd:YAG laser and pumping a multiple input, single output fiber squid. Beam cleanup of the resulting output beam using stimulated Raman scattering was then demonstrated in both 100 μm fiber (Stokes M2 = 1.86) and 200 μm fiber (Stokes M2 = 1.40). The performance of the 200 μm fiber was compared to that of the 100 μm fiber. Energy conversion efficiency into the Stokes beam was measured as a function of input energy and found to be limited by the attenuation characteristics of the fiber. …


Modeling E & F Region Ionospheric Response To X-Ray Solar Flares, Annette M. Parsons Mar 2006

Modeling E & F Region Ionospheric Response To X-Ray Solar Flares, Annette M. Parsons

Theses and Dissertations

This research takes an existing ionospheric model and modifies it to include the effects of solar flare activity. Solar flares are a localized explosive release of magnetic energy that appears as a sudden, short-lived brightening in the sun’s chromosphere. This additional energy is deposited in the earth’s ionosphere, temporarily changing its properties, which can affect military communications. Studying the effects of moderate solar flares will improve our understanding of the ionosphere’s response, leading to better operational models. Modification of the model is accomplished by adding a flare irradiance model to represent solar irradiance changes due to a flare. The irradiance …


Prediction Of Flight-Level Radiation Hazards Due To Solar Energetic Protons, Matthew P. Sattler Mar 2006

Prediction Of Flight-Level Radiation Hazards Due To Solar Energetic Protons, Matthew P. Sattler

Theses and Dissertations

The radiation environment at aircraft altitudes is caused primarily by high-energy particles originating from outside the near-earth environment. These particles generally come from outside our solar system and are called galactic cosmic rays. Occasionally however, a transient solar event will also accelerate energetic protons toward the earth. If these protons reach the upper atmosphere, they produce secondary particles via collisions, resulting in increased radiation levels in the atmosphere. Air crews and electronic systems flying at high altitudes during one of these events are subjected to these increased levels of radiation which can result in health problems for personnel and soft …


Reproducibility Distinguishability And Correlation Of Fireball And Shockwave Dynamics In Explosive Munitions Detonations, Bryan J. Steward Mar 2006

Reproducibility Distinguishability And Correlation Of Fireball And Shockwave Dynamics In Explosive Munitions Detonations, Bryan J. Steward

Theses and Dissertations

The classification of battlespace detonations, specifically the determination of munitions type and size using temporal and spectral features of infrared emissions, is a particularly challenging problem. The intense infrared radiation produced by the detonation of high explosives is largely unstudied. Furthermore, the time-varying fireball imagery and spectra are driven by many factors including the type, size and age of the chemical explosive, method of detonation, interaction with the environment, and the casing used to enclose the explosive. To distinguish between conventional military munitions and improvised or enhanced explosives, the current study investigates fireball expansion dynamics using high speed, multi-band imagery. …