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Air Force Institute of Technology

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Two-Dimensional Steady Boussinesq Convection: Existence, Computation And Scaling, Jeremiah S. Lane, Benjamin F. Akers Benjamin.Akers@Afit.Edu Nov 2021

Two-Dimensional Steady Boussinesq Convection: Existence, Computation And Scaling, Jeremiah S. Lane, Benjamin F. Akers Benjamin.Akers@Afit.Edu

Faculty Publications

This research investigates laser-induced convection through a stream function-vorticity formulation. Specifically, this paper considers a solution to the steady Boussinesq Navier–Stokes equations in two dimensions with a slip boundary condition on a finite box. A fixed-point algorithm is introduced in stream function-vorticity variables, followed by a proof of the existence of steady solutions for small laser amplitudes. From this analysis, an asymptotic relationship is demonstrated between the nondimensional fluid parameters and least upper bounds for laser amplitudes that guarantee existence, which accords with numerical results implementing the algorithm in a finite difference scheme. The findings indicate that the upper bound …


Optimizing Critical Values And Combining Axes For Multi-Axial Neck Injury Criteria, Ethan J. Gaston Mar 2021

Optimizing Critical Values And Combining Axes For Multi-Axial Neck Injury Criteria, Ethan J. Gaston

Theses and Dissertations

The Air Force employs ejection seats in its high-performance aircraft. While these systems are intended to ensure aircrew safety, the ejection process subjects the aircrew to potentially injurious forces. System validation includes evaluation of forces against a standard which is linked to the probability of injury. The Muti-Axial Neck Injury Criteria (MANIC) was developed to account for forces in all six degrees of freedom. Unfortunately, the MANIC is applied to each of the three linear input directions separately and applies different criterion values for each direction. These three separate criteria create a lack of clarity regarding acceptable neck loading, leading …


A Study Of Onboarding And Turnover Mediating Variables In U.S. Air Force Officers, Brett S. Bowers Sep 2019

A Study Of Onboarding And Turnover Mediating Variables In U.S. Air Force Officers, Brett S. Bowers

Theses and Dissertations

Employee retention, while always a concern in the workplace, has become a greater challenge for organizations in recent years. Today’s working class has displayed a propensity to change jobs more rapidly than previous generations, exacerbating not only turnover rates but also the costs associated with them (Frankel, 2016). This challenge is especially relevant to the United States Air Force, which has experienced difficulty retaining young officers in recent years. The problems resulting from this voluntary turnover are exceedingly impactful to the military command structure, as senior leaders must work their way up from the lowest ranks. As such, the Air …


United States Air Force Applications Of Unmanned Aerial Systems: Modernizing Airfield Damage Assessment, Samuel M. Clark Mar 2018

United States Air Force Applications Of Unmanned Aerial Systems: Modernizing Airfield Damage Assessment, Samuel M. Clark

Theses and Dissertations

Modernizing airfield damage assessment has long been a priority mission at the Air Force Civil Engineer Center (AFCEC). Previously, AFCEC has made advances to expedite unexploded ordnance (UXO) neutralization and pavement repair. Missing from these initiatives is the initial assessment component. This thesis expands the idea of using Small Unmanned Aerial Systems (SUAS), applies it to the Air Force mission, and provides SUAS vehicle configuration and sensor recommendations. In this study, 25 civil engineer officers reviewed airfield imagery gathered using two small air vehicles. For the first review, participants attempted to identify UXOs and foreign object debris (FOD) in a …


They're Only Nuclear Weapons: An Exploratory Analysis Of Safety Climate Within The Nuclear Enterprise, Brandon M. Clements Mar 2018

They're Only Nuclear Weapons: An Exploratory Analysis Of Safety Climate Within The Nuclear Enterprise, Brandon M. Clements

Theses and Dissertations

By possessing nuclear weapons, the United States Air Force is inherently exposed to extreme safety concerns. With multiple setbacks in recent years (e.g., unauthorized transport of nuclear weapons, cheating scandals, and career dissatisfaction), some have begun to wonder how safe the nuclear enterprise truly is. Building upon the concept of safety climate, this study explores safety climate constructs and trends associated with current nuclear maintenance safety climate survey data.


Influencing Effective Electrical Distribution Modernization Through Advanced Metering, Jared R. Erickson Mar 2018

Influencing Effective Electrical Distribution Modernization Through Advanced Metering, Jared R. Erickson

Theses and Dissertations

In 2013, the Department of Defense (DoD) required its services to implement advanced metering for the purpose of reducing energy usage (Department of Defense, 2013). Additionally, the DoD has aimed to improve its ability to assure a continuous energy supply to all of its installations. This study investigated processes for applying advanced meters on Air Force bases to increase energy assurance. This study also identified strategies for using advanced meters to influence infrastructure funding. This was accomplished through the use of extensive advanced meter data. The data was analyzed for outages and a procedure was created to locate outages in …


Autoencoded Reduced Clusters For Anomaly Detection Enrichment (Arcade) In Hyperspectral Imagery, Brenden A. Mclean Mar 2016

Autoencoded Reduced Clusters For Anomaly Detection Enrichment (Arcade) In Hyperspectral Imagery, Brenden A. Mclean

Theses and Dissertations

Anomaly detection in hyper-spectral imagery is a relatively recent and important research area. The shear amount of data available in a many hyper-spectral images makes the utilization of multivariate statistical methods and artificial neural networks ideal for this analysis. Using HYDICE sensor hyper-spectral images, we examine a variety of preprocessing techniques within a framework that allows for changing parameter settings and varying the methodological order of operations in order to enhance detection of anomalies within image data. By examining a variety of different options, we are able to gain significant insight into what makes anomaly detection viable for these images, …


Optimizing Allocation Of U.S. Humanitarian Civic Assistance Projects In Support Of Developing Foreign Democracy, Christopher E. Wittman Mar 2016

Optimizing Allocation Of U.S. Humanitarian Civic Assistance Projects In Support Of Developing Foreign Democracy, Christopher E. Wittman

Theses and Dissertations

Humanitarian projects in foreign countries are funded by the U.S. government to foster peace, prosperity, and the spread of democratic ideals around the globe. The type and scope of projects are restricted by current doctrine and funding regulations. Specifically in 2014, USAF personnel supported medical and educational construction projects/programs in the country of Belize. Within Belize, medical and educational projects were funded under the Humanitarian and Civic Assistance (HCA) program through the NEW HORIZONS exercise. Fiscal constraints, including shrinking budgets due to sequestration, have placed greater emphasis in the responsible distribution of resources and foreign assistance. The purpose of this …


Scientometric Analysis Of Technology & Innovation Management Literature, Kadir Yildiz Mar 2016

Scientometric Analysis Of Technology & Innovation Management Literature, Kadir Yildiz

Theses and Dissertations

The management of technology and innovation has become an attractive and promising field within the management discipline. Therefore, much insight can be gained by reviewing the Technology & Innovation Management (TIM) research in leading TIM journals to identify and classify the key TIM issues by meta-categories and to identify the current trends. Based on a comprehensive scientometric analysis of 5,591 articles in 10 leading TIM specialty journals from 2005 to 2014, this research revealed several enlightening findings. First, the United States is the major producer of TIM research literature, and the greatest number of papers was published in Research Policy …


Satellite Ephemeris Correction Via Remote Site Observation For Star Tracker Navigation Performance Improvement, Jorge E. Diaz Mar 2016

Satellite Ephemeris Correction Via Remote Site Observation For Star Tracker Navigation Performance Improvement, Jorge E. Diaz

Theses and Dissertations

In order for celestial navigation observing satellites to provide accurate positioning estimates, precise ephemerides of the observed satellites are necessary. This work analyzed a method to correct for satellite ephemeris to be used in celestial navigation applications. This correction is the measured angle differences between the expected location of the satellite, which is given by propagating publicly available Two-Line Elements (TLE), and their observed angles from a precisely known reference site. Therefore, the angle difference can be attributed completely to satellite ephemeris error assuming instrument error was accounted for. The intent is to calculate this correction from the reference site …


A Change Management Approach To Enhance Facility Maintenance Programs, Stanton P. Brown Mar 2014

A Change Management Approach To Enhance Facility Maintenance Programs, Stanton P. Brown

Theses and Dissertations

A recent study assigned a grade of D+ on the nation's public infrastructure. Because of this poor asset condition, many organizations tend to respond to maintenance in a reactive mode; however, relying on corrective maintenance leads to increased maintenance costs due to unplanned downtime, increased labor costs, and inefficient use of personnel. To address this situation, asset management (AM) principles should be employed to transition organizations towards a proactive maintenance program. Unfortunately, it has been shown that two-thirds of the organizations failed to implement general change efforts. Therefore, an organizational change management framework should be followed to implement a change …


The Future Of Mobile Information And Communication Technology In Austere Environments: A Command And Control Technology Integration Perspective, James W. Harker Mar 2013

The Future Of Mobile Information And Communication Technology In Austere Environments: A Command And Control Technology Integration Perspective, James W. Harker

Theses and Dissertations

The information and communications technology (ICT) field is undergoing a period of tremendous and rapid change. As ICT develops more rapidly, the United States Air Force needs to remain responsive and adaptive to maintain military advantages. The need to integrate ICT developments sooner than our adversaries prompted an assessment of guidelines evaluating how well the AF is doctrinally positioned from a Command and Control perspective to support integration of emerging ICT. A Delphi Study was commissioned by the 689th CCW to forecast the future of mobile Information and Communication Technology (ICT) in austere environments. Using the ICT forecast data as …


Air-To-Air Missile Vector Scoring, Nicholas Sweeney Mar 2012

Air-To-Air Missile Vector Scoring, Nicholas Sweeney

Theses and Dissertations

An air-to-air missile vector scoring system is proposed for test and evaluation applications. Three different linear missile dynamics models are considered: a six-state constant velocity model and nine-state constant acceleration and three-dimensional coordinated turn models. Frequency modulated continuous wave radar sensors, carefully located to provide spherical coverage around the target, provide updates of missile kinematic information relative to a drone aircraft. Data from the radar sensors is fused with predictions from one of the three missile models using either an extended Kalman filter, an unscented Kalman filter or a particle filter algorithm. The performance of all nine model/filter combinations are …


Mitigating Diminishing Manufacturing Sources/Material Shortages (Dms/Ms) And Obsolescence For The T-6 Canopy Fracturing Initiation System (Cfis), Richard P. Carrano Mar 2012

Mitigating Diminishing Manufacturing Sources/Material Shortages (Dms/Ms) And Obsolescence For The T-6 Canopy Fracturing Initiation System (Cfis), Richard P. Carrano

Theses and Dissertations

The Joint Primary Aircraft Training System (JPATS) lost the supplier for its canopy fracturing initiation system (CFIS) with no prospect for a replacement. This forced a complete CFIS redesign to supply both an active production line and sustain fielded aircraft. Compounding the problem, the existing CFIS became obsolete, which forced an interim design to be produced until a final long term solution was fielded. This thesis developed a method to optimize the redesign by determining the lowest cost path for both fielding the interim design and phasing in the final retrofit. Using the Excel Solver® modeling program, an optimal rate …


Simplified Daylight Spectrum Approximation By Blending Two Light Emitting Diode Sources, Jacob M. Gilman Mar 2012

Simplified Daylight Spectrum Approximation By Blending Two Light Emitting Diode Sources, Jacob M. Gilman

Theses and Dissertations

Energy-conscious facility designs strive to include natural daylight in workspaces. To improve the efficiency of illumination, significant efforts are underway to adopt more efficient light emitting diode (LED) lamps and to effectively integrate daylight with active dimming of electric lighting. However, the correlated color temperature (CCT) and spectral content of daylight varies throughout the day while existing electric light sources produce light with a fixed CCT, resulting in mixed-illumination environments. The color rendering requirements for a lamp that permits the selection of color temperature across a significant portion of the daylight locus is explored. The analysis indicates that it is …


Infrastructure Asset Management Modeling Through An Analysis Of The Air Force Strategic Vision And Goals, Marie T. Harnly Mar 2012

Infrastructure Asset Management Modeling Through An Analysis Of The Air Force Strategic Vision And Goals, Marie T. Harnly

Theses and Dissertations

Effective asset management requires an overarching model that establishes a framework for decision-makers. This research project develops a strategic level asset management model for varying types of infrastructure that provides guidance for effective asset management. The strategic model also incorporates Next Generation Information Technology initiatives into a single coherent system to streamline the top-down, bottom-up flow of information. The strategic model is applicable to agencies with a large, varying infrastructure inventory and limited resources. This research also develops an improved performance modeling tool, a critical component of the strategic model. This tool objectively prioritizes maintenance and repair projects according to …


Electroluminescence Studies On Longwavelength Indium Arsenide Quantum Dot Microcavities Grown On Gallium Arsenide, John C. Ramsey Dec 2011

Electroluminescence Studies On Longwavelength Indium Arsenide Quantum Dot Microcavities Grown On Gallium Arsenide, John C. Ramsey

Theses and Dissertations

A comprehensive study of the electroluminescence of four GaAs/AlGaAs microcavity devices with InAs/GaInAs quantum dot active regions emitting near 1.3 µm was conducted. The four molecular beam epitaxial grown samples with AlAs oxide aperture confinement layers were fabricated, characterized, and optically modeled. Optical power transmission of the samples was modeled using Matlab and compared with measured transmission data. Resonant cavity light emitting diodes (RCLEDs) and three vertical cavity surface emitting laser (VCSEL) samples were fabricated and electro-optically characterized over a range of injection currents and temperatures. Devices achieved continuous wave room temperature lasing at 1.28 µm with an output power …


Major Cost Drivers Of Motor Vehicle Crashes Involving Air Force Military Personnel And The Influence Of The Military Environment, Ilias Kesisiklis Sep 2011

Major Cost Drivers Of Motor Vehicle Crashes Involving Air Force Military Personnel And The Influence Of The Military Environment, Ilias Kesisiklis

Theses and Dissertations

Motor vehicle crashes (MVCs) involving USAF military personnel when off duty/off base are a critical concern for the Department of Defense (DoD), due to potential impact on mission readiness. In addition, the cost of MVCs places excessive financial burden on the USAF budget, apart from productivity loss and negative emotional consequences on the victims. In particular, total injury cost was $ 356M, based on 2010 CY dollars. Determining the underlying factors leading to MVCs is crucial to establishing effective preventive measures to mitigate the negative consequences of MVCs.
This thesis applied categorical data and multiple regression analyses on (AFSC) historical …


Coverage Of Continuous Regions In Euclidean Space Using Homogeneous Resources With Application To The Allocation Of The Phased Array Radar Systems, Kassandra M. Merritt Jun 2011

Coverage Of Continuous Regions In Euclidean Space Using Homogeneous Resources With Application To The Allocation Of The Phased Array Radar Systems, Kassandra M. Merritt

Theses and Dissertations

Air surveillance of United States territory is an essential Department of Defense function. In the event of an incoming aerial attack on North America, the DoD, Department of Homeland Security, and Federal Aviation Administration surveillance capabilities are critical to discovering and tracking the threat so that it can be eliminated. Many of the currently used surveillance radar will reach the end of their design life within ten to twenty years. By replacing the current radar network with a single integrated network of Multifunction Phased Array Radar (MPAR) units, surveillance capabilities can be enhanced and life cycle cost can be reduced. …


Quest Hierarchy For Hyperspectral Face Recognition, David M. Ryer Mar 2011

Quest Hierarchy For Hyperspectral Face Recognition, David M. Ryer

Theses and Dissertations

Face recognition is an attractive biometric due to the ease in which photographs of the human face can be acquired and processed. The non-intrusive ability of many surveillance systems permits face recognition applications to be used in a myriad of environments. Despite decades of impressive research in this area, face recognition still struggles with variations in illumination, pose and expression not to mention the larger challenge of willful circumvention. The integration of supporting contextual information in a fusion hierarchy known as QUalia Exploitation of Sensor Technology (QUEST) is a novel approach for hyperspectral face recognition that results in performance advantages …


Perimeter Security And Intruder Detection Using Gravity Gradiometry: A Feasibility Study, Jared D. Tuinstra Mar 2011

Perimeter Security And Intruder Detection Using Gravity Gradiometry: A Feasibility Study, Jared D. Tuinstra

Theses and Dissertations

Changes in the mass distribution around some point on the Earth’s surface induce corresponding changes to the magnitude and direction of the gravity vector at that location. The nine-tensor derivative of the gravity vector, or gravity gradient, is sensitive to very small changes in the gravity vector. With some assumptions, continuous measurement of the gravity gradient using a gravity gradiometer (GGI) is used to determine the location of a mass change in the local area near the instrument. This investigation sought to determine the effectiveness, operating characteristics, and limitations of a physical perimeter security system that uses an array of …


A Century Long Pursuit Of Alternative Fuels And Feedstocks: A Content Analysis, Elias J. Halvorson Mar 2011

A Century Long Pursuit Of Alternative Fuels And Feedstocks: A Content Analysis, Elias J. Halvorson

Theses and Dissertations

he United States has dramatically increased its production of alternative fuels over the past seven years. With the passing of the Energy Independence and Security Act of 2007 (EISA), alternative fuel production will increase in the United States over 700% from 2005 levels. However, the pursuit of petroleum alternatives is not a recent trend. Over the last 100 years, various nations have pursued petroleum alternatives with varying levels of success. This research focuses on the historical development of 10 leading alternative fuels and feedstocks. Through a thorough literature review we will identify commonalities among these fuels and feedstocks which have …


A Systems Architecture And Advanced Sensors Application For Real-Time Aircraft Structural Health Monitoring, Hyoungjin Shin, Edward C. Beckett Mar 2011

A Systems Architecture And Advanced Sensors Application For Real-Time Aircraft Structural Health Monitoring, Hyoungjin Shin, Edward C. Beckett

Theses and Dissertations

Aircraft are being pushed beyond their original service life, increasing the potential for structural failures. A catastrophic in flight failure of an F-15 bulkhead and severe cracking in the C-130 Wing rainbow fitting are two recent examples that have caused major problems for the Air Force. Previous Aircraft Structural Health Monitoring Systems research primarily explored using a system during the ground maintenance phase. This research will explore a Real-Time Aircraft Structural Health Monitoring System (RTASHMS) that includes a ground phase as well as an in-flight phase. The RTASHMS will continuously analyze structural hot spots, detect critical structural damage or cracks …


Information Technology Implementation And Sustainment Model: Data Collection Instrument, Walter K. Yazzie Mar 2005

Information Technology Implementation And Sustainment Model: Data Collection Instrument, Walter K. Yazzie

Theses and Dissertations

The goal of this research was to develop a data collection instrument for an existing information technology implementation and sustainment model. In 2003, a unique system dynamics model was developed at the Air Force Institute of Technology to predict the behavior of information technology implementation and sustainment (Fonnesbeck, 2003). However, no empirical data was used during the model development. In order to collect the needed empirical data, this research develops a data collection instrument for the model. The instrument was sent to 60 Air Force community planners who are currently implementing a geographical information system (Air Force GeoBase) into their …


Creating Cost Growth Models For The Engineering And Manufacturing Development Phase Of Acquisition Using Logistic And Multiple Regression, Brandon M. Lucas Mar 2004

Creating Cost Growth Models For The Engineering And Manufacturing Development Phase Of Acquisition Using Logistic And Multiple Regression, Brandon M. Lucas

Theses and Dissertations

Cost growth remains a concern for cost analysts, program managers, senior DoD decision-makers, Congress, and even the American public. All of these people have a vested interest in the cost of DoD programs and most would like to see those costs decrease; as such, we need additional tools to help combat cost growth. Previous research creates the foundation for the use of a two-step methodology to help predict cost growth, which we follow closely. First, utilizing logistic regression we analyze whether specific program characteristics predict cost growth within the Engineering and Manufacturing Development (EMD) phase for combined RDT&E and procurement …


Estimating Cost Growth In Engineering And Schedule Cost Categories Using A Two-Pronged Regression Approach, Chris J. Mcdaniel Mar 2004

Estimating Cost Growth In Engineering And Schedule Cost Categories Using A Two-Pronged Regression Approach, Chris J. Mcdaniel

Theses and Dissertations

This research confirms the usefulness of the logistic and multiple regression two-step procedure for assessing cost growth in major DoD weapon systems. We compile programmatic data from the Selected Acquisition Reports (SARs) between 1990 and 2002 for programs covering all defense departments. Our analysis concentrates on cost growth in the procurement appropriations of the Engineering and Manufacturing Development phase of acquisitions. We investigate the use of logistic regression in cost growth analysis to predict whether or not cost growth will occur in a program. If applicable, multiple regression is implemented to predict how much cost growth will occur. Our study …


A Multiobjective Approach Applied To The Protein Structure Prediction Problem, Richard O. Day Mar 2002

A Multiobjective Approach Applied To The Protein Structure Prediction Problem, Richard O. Day

Theses and Dissertations

Interest in discovering a methodology for solving the Protein Structure Prediction problem extends into many fields of study including biochemistry, medicine, biology, and numerous engineering and science disciplines. Experimental approaches, such as, x-ray crystallographic studies or solution Nuclear Magnetic Resonance Spectroscopy, to mathematical modeling, such as minimum energy models are used to solve this problem. Recently, Evolutionary Algorithm studies at the Air Force Institute of Technology include the following: Simple Genetic Algorithm (GA), messy GA, fast messy GA, and Linkage Learning GA, as approaches for potential protein energy minimization. Prepackaged software like GENOCOP, GENESIS, and mGA are in use to …


A Verification And Validation Assessment Of Rapid Availability Prototyping For Testing Operational Readiness, Gurhan Tarman Mar 2001

A Verification And Validation Assessment Of Rapid Availability Prototyping For Testing Operational Readiness, Gurhan Tarman

Theses and Dissertations

Throughout the world, new techniques are developed to test and evaluate systems. The Department of Defense and the US Air Force conduct numerous studies into the reliability and maintainability of current and future weapons systems in an effort to understand the reliability, maintainability, and availability (RM&A) costs of these systems. Furthermore, they must verify RM&A characteristics of systems, which are still in the development phase. The Air Force Operational Test and Evaluation Center (AFOTEC) is responsible for testing new equipment to ensure their RM&A characteristics meet specifications. Rapid Availability Prototyping for Testing Operational Readiness (RAPTOR) is the software tool developed …


Decision Boundary Analysis Feature Selection For Breast Cancer Diagnosis, Daniel W. Gregg Mar 1997

Decision Boundary Analysis Feature Selection For Breast Cancer Diagnosis, Daniel W. Gregg

Theses and Dissertations

The general pattern recognition problem always involves the extraction of features to be used in pattern classification. There are no theoretical limitations to the number of features which can be obtained for a given pattern recognition problem. This research will develop a correlation procedure for screening a large feature set without the use of a trained classifier. The results will be compared to established saliency metrics such as the Fisher ratio and derivative-based techniques such as Ruck's saliency.