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Theses and Dissertations

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Full-Text Articles in Other Engineering

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 …


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 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 …


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 …


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.


An Exploratory Survey Of Methods Used To Develop Measures Of Performance, Kenneth L. Hamner, Charles A. Lafleur Sep 1993

An Exploratory Survey Of Methods Used To Develop Measures Of Performance, Kenneth L. Hamner, Charles A. Lafleur

Theses and Dissertations

Nonmanufacturing organizations are being challenged to provide high- quality products and services to their customers, with an emphasis on continuous process improvement. Measures of performance, referred to as metrics, can be used to foster process improvement. The application of performance measurement to nonmanufacturing processes can be very difficult. This research explored methods used to develop metrics in nonmanufacturing Organizations. Several methods were formally defined in the literature, and the researchers used a two- step screening process to determine the OMB Generic Method was most likely to produce high-quality metrics. The OMB Generic Method was then used to develop metrics. A …