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Theses and Dissertations

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Full-Text Articles in Engineering

Binary Classification Of An Unknown Object Through Atmospheric Turbulence Using A Polarimetric Blind-Deconvolution Algorithm Augmented With Adaptive Degree Of Linear Polarization Priors, Mu J. Kim Mar 2012

Binary Classification Of An Unknown Object Through Atmospheric Turbulence Using A Polarimetric Blind-Deconvolution Algorithm Augmented With Adaptive Degree Of Linear Polarization Priors, Mu J. Kim

Theses and Dissertations

This research develops an enhanced material-classification algorithm to discriminate between metals and dielectrics using passive polarimetric imagery degraded by atmospheric turbulence. To improve the performance of the existing technique for near-normal collection geometries, the proposed algorithm adaptively updates the degree of linear polarization (DoLP) priors as more information becomes available about the scene. Three adaptive approaches are presented. The higher-order super-Gaussian method fits the distribution of DoLP estimates with a sum of two super-Gaussian functions to update the priors. The Gaussian method computes the classification threshold value, from which the priors are updated, by fitting the distribution of DoLP estimates …

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Augmenting The Global Positioning System With Foreign Navigation Systems And Alternative Sensors, Christopher B. Killion Mar 2012

Augmenting The Global Positioning System With Foreign Navigation Systems And Alternative Sensors, Christopher B. Killion

Theses and Dissertations

The United States Global Positioning System (GPS), with its great accuracy, receives extensive use by civilians and military organizations throughout the world. However, in areas with limited or partially obstructed views of the sky, such as amongst tall buildings or imposing geographic features, a position solution can be difficult or impossible to obtain as the limited view of the sky decreases the number of visible satellites. Augmenting the GPS constellation by receiving signals from foreign satellite navigation systems as well as using measurements from inertial and barometric sensors can increase the availability of a position solution in a degraded reception …

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Target Classification Of Canonical Scatterers Using Classical Estimation And Dictionary Based Techniques, G. Barry Hammond Ii Mar 2012

Target Classification Of Canonical Scatterers Using Classical Estimation And Dictionary Based Techniques, G. Barry Hammond Ii

Theses and Dissertations

This research effort will utilize a hierarchical dictionary-based approach for canonical shape classification within measured synthetic aperture radar (SAR) phase history data. This primary goal of this research is to develop an efficient framework for dictionary based SAR feature extraction using modi ed 3-D radar scattering models. Previous work in this area relies on maximum likelihood (ML) estimation and similar approaches to extract shapes using 2-D signal models. We include characterizations of shape model redundancies caused by similar shape scattering responses. Simulated SAR collection methods, including frequency, elevation aspect, and polarization diversities, are modeled to show reductions in inter-atom correlation. …

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Exploiting The Automatic Dependent Surveillance-Broadcast System Via False Target Injection, Domenic Magazu Iii Mar 2012

Exploiting The Automatic Dependent Surveillance-Broadcast System Via False Target Injection, Domenic Magazu Iii

Theses and Dissertations

A new aircraft surveillance system, Automatic Dependent Surveillance-Broadcast (ADS-B), is being introduced by the Federal Aviation Administration (FAA) with mandated implementation in the United States by the year 2020. The rapid deployment of the system with current test-beds spread across the U.S. leaves very little chance for anyone to test the abilities of the system and more importantly the flaws of the system. The research conducted within this thesis explores some of the weaknesses of the system to include the relative ease with which false aircraft targets can be injected. As part of a proof of concept, false ADS-B messages …

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External Verification Of Scada System Embedded Controller Firmware, Lucille R. Mcminn Mar 2012

External Verification Of Scada System Embedded Controller Firmware, Lucille R. Mcminn

Theses and Dissertations

Critical infrastructures such as oil and gas pipelines, the electric power grid, and railways, rely on the proper operation of supervisory control and data acquisition (SCADA) systems. Current SCADA systems, however, do not have sufficient tailored electronic security solutions. Solutions available are developed primarily for information technology (IT) systems. Indeed, the toolkit for SCADA incident prevention and response is unavailing as the operating parameters associated with SCADA systems are different from IT systems. The unique environment necessitates tailored solutions. Consider the programmable logic controllers (PLCs) that directly connect to end physical systems for control and monitoring of operating parameters -- …

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Uhf Antenna Design For Afit Random Noise Radar, Matthew T. Ludwig Mar 2012

Uhf Antenna Design For Afit Random Noise Radar, Matthew T. Ludwig

Theses and Dissertations

The design of a small ultra-high frequency (UHF) antenna for an ultra-wideband (UWB) random noise radar (RNR) system was undertaken to improve system bandwidth and reduce overall system size. The Vivaldi dipole antenna class showed the greatest potential for high performance in this specific application. After extensive computer simulation, three designs were built using two printed circuit board antenna construction methods. The antipodal chopped Vivaldi dipole antenna, built with a milling machine, achieved a wider bandwidth and more uniform spectral performance characteristics. Though current results show improvement over the current log-periodic antenna (LPA) used on the system, greater performance could …

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Ladar Range Image Interpolation Exploiting Pulse Width Expansion, Jeramy W. Motes Mar 2012

Ladar Range Image Interpolation Exploiting Pulse Width Expansion, Jeramy W. Motes

Theses and Dissertations

Laser Detection and Ranging (LADAR) systems produce both a range image and an intensity image by measuring the intensity of light reflected off a surface target. When the transmitted LADAR pulse strikes a sloped surface, the returned pulse is expanded temporally. This characteristic of the reflected laser pulse enables the possibility of estimating the gradient of a surface. This study estimates the gradient of the surface of an object from a modeled LADAR return pulse that includes accurate probabilistic noise models. The range and surface gradient estimations are incorporated into a novel interpolator that facilitates an effective three dimensional (3D) …

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Timing Variations In A Magnetic Pulse Compression Circuit, Jeremy S. Oliver Mar 2012

Timing Variations In A Magnetic Pulse Compression Circuit, Jeremy S. Oliver

Theses and Dissertations

The magnetic pulse compression (MPC) circuit uses saturable core inductors and capacitors to compress the width of a pulse. This substantially increases the peak power of the initially applied pulse. The saturable inductor exhibits a hysteresis curve behavior. One particular problem with these MPC circuits is timing variances in the pulse rate of the system. This work models the unique characteristics and signatures of the timing variations of magnetic switches and pulse compressors. The hysteresis curve of the saturable inductor was created by using a nonlinear inductor and a nonlinear resistor in parallel as a substitute for saturable inductors. The …

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Passive Multistatic Radar Imaging Using An Ofdm Based Signal Of Opportunity, Matthew B. P. Rapson Mar 2012

Passive Multistatic Radar Imaging Using An Ofdm Based Signal Of Opportunity, Matthew B. P. Rapson

Theses and Dissertations

This paper demonstrates a proof of concept in using an OFDM-based signal of opportunity for SAR imaging purposes within a passive, multistatic radar construct. Two signal processing methods have been proposed to create phase history data. The same methods are applied in both a simulated software model and an experimental data collection environment to produce simulated SAR images using the CBP imaging algorithm. The images generated from both the experimental and simulated data were observed to be consistent with each other and with expectations in terms of resolution. Coherent addition of the images results in improved image resolution due to …

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Application Of Game Theory To Improve The Defense Of The Smart Grid, Keith J. Ross Mar 2012

Application Of Game Theory To Improve The Defense Of The Smart Grid, Keith J. Ross

Theses and Dissertations

This thesis presents the development and evaluation of a distributed agent based system using reputation based trust and game theoretic techniques to improve the defense of the future smart grid from cyber-attack and equipment malfunctions. Future smart grid capabilities promise to leverage network technologies to revolutionize the production, transmission, distribution and consumption of electrical power. However, the internet like communication also increase the power grid's vulnerability to cyber-attack. This thesis uses simulation linking power systems with communication networks to demonstrate the benefits of a Distributed Decision Making Communication Enable Special Protection System (SPS) using reputation based trust and game theory …

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Electromagnetic Characterization Of Inhomogeneous Media, Marcus A. Sitterly Mar 2012

Electromagnetic Characterization Of Inhomogeneous Media, Marcus A. Sitterly

Theses and Dissertations

Developed two permittivity profile extraction algorithms for inhomogeneous materials. These two algorithms were created using discrete and continuous approaches. The discrete method used a piece-wise constant permittivity assumption that allowed the use of homogeneous wave equations. Using laboratory data and a theoretical formulation, the permittivity of each piece-wise constant layer within the material was extracted using a root search algorithm. The continuous approach solved the problem using inhomogeneous wave equations. These equations were used to extract a linear permittivity profile using laboratory data and a root search.

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A High Bandwidth Non-Destructive Method For Characterizing Simple Media, Matthew L. Szuster Mar 2012

A High Bandwidth Non-Destructive Method For Characterizing Simple Media, Matthew L. Szuster

Theses and Dissertations

The relative complex permittivity can be extracted with time domain data from a perfect electrical conductor (PEC) backed sample of a low-loss, non-dispersive dielectric using dual ridged waveguide aperture probes with attached PEC flange plates of the same geometry and different dimensions. The temporal domain measurement of interest is the ability to detect the reflection from the edge of the flange plate in the parallel region created by the flange plate and the PEC backing on the dielectric sample. Signal processing windows are applied to the data in order to exploit this edge reflection. The types of signal processing methods …

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Simultaneous Range-Velocity Processing And Snr Analysis Of Afit's Random Noise Radar, T. Joel Thorson Mar 2012

Simultaneous Range-Velocity Processing And Snr Analysis Of Afit's Random Noise Radar, T. Joel Thorson

Theses and Dissertations

This paper presents two research objectives aimed at advancing the AFIT RNR signal processing algorithm and modeling capability toward the overarching goal of performing collision avoidance on an autonomous vehicle. In both research efforts, analytical, simulated, and measured results are provided and used to draw research conclusions. The first research effort is aimed at reducing the memory required for 2D processing in the time domain in order to distribute the processing algorithm across hundreds of processors on a GPU. Distributed processing reduces the overall 2D processing time and the feasibility of a near real-time implementation is studied. The second effort …

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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 …

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Distributed Localization Of Active Transmitters In A Wireless Sensor Network, Oba L. Vincent Mar 2012

Distributed Localization Of Active Transmitters In A Wireless Sensor Network, Oba L. Vincent

Theses and Dissertations

In today's military environment, emphasis has been placed on bandwidth efficiency and total use of the available spectrum. Current communication standards divide the spectrum into several different frequency bands, all of which are assigned to one or multiple primary users. Cognitive Radio utilizes potential white spaces that exist between currently defined channels or in time. One under-explored dimension of white space exploration is spatial. If a frequency band is being used in one region, it may be underutilized, or not occupied in another. Using an active localization method can allow for the discovery of spatial white; trying to spatially map …

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An Inquiry: Effectiveness Of The Complex Empirical Mode Decomposition Method, The Hilbert-Huang Transform, And The Fast-Fourier Transform For Analysis Of Dynamic Objects, Kristen L. Wallis Mar 2012

An Inquiry: Effectiveness Of The Complex Empirical Mode Decomposition Method, The Hilbert-Huang Transform, And The Fast-Fourier Transform For Analysis Of Dynamic Objects, Kristen L. Wallis

Theses and Dissertations

A review of current signal analysis tools show that new techniques are required for an enhanced fidelity or data integrity. Recently, the Hilbert-Huang transform (HHT) and its inherent property, the Empirical Mode Decomposition (EMD) technique, have been formerly investigated. The technique of Complex EMD (CEMD) was also explored. The scope of this work was to assess the CEMD technique as an innovative analysis tool. Subsequent to this, comparisons between applications of the Hilbert transform (HT) and the Fast-Fourier transform (FFT) were analyzed. MATLAB was implemented to model signal decomposition and the execution of mathematical transforms for generating results. The CEMD …

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Silicon Carbide Capacitive High Temperature Mems Strain Transducer, Richard P. Weisenberger Mar 2012

Silicon Carbide Capacitive High Temperature Mems Strain Transducer, Richard P. Weisenberger

Theses and Dissertations

Air Force Research Lab Air Vehicles directorate performs research on hypersonic vehicles. To verify materials or designs of hypersonic vehicles, they have a need to measure strain at temperatures exceeding 700°C. Strain sensors have the ability to measure strain. Strain is the deformation of materials due to internal stresses in a material. Internal stresses occur when a material is subjected to a force. Traditional strain sensors use Piezoresistive effects to measure strain, which is temperature dependent and making them unusable at high temperatures. This paper discusses a novel strain sensing device, sensing capacitance instead of piezoresistance. The strain sensor is …

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A Performance Analysis Of The Optimized Link State Routing Protocol Using Voice Traffic Over Mobile Ad Hoc Networks, André Wolf Mar 2012

A Performance Analysis Of The Optimized Link State Routing Protocol Using Voice Traffic Over Mobile Ad Hoc Networks, André Wolf

Theses and Dissertations

Mobile ad hoc networks (MANETs) have grown in popularity over the past decade and are increasingly considered for time-sensitive multimedia applications. The impact of various routing protocols on voice traffic using different IEEE 802.11 extensions has been investigated via analytical models, simulations and experimental test beds. Many studies determined that optimized link state routing (OLSR) is a suitable routing protocol to support voice over internet protocol (VoIP) conversations. This research expands upon this understanding by determining the point at which voice traffic is no longer feasible in an ad hoc environment and determines which audio codec is best suited for …

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Theoretical Study Of The Effects Of Di-Muonic Molecules On Muon-Catalyzed Fusion, Eugene V. Sheely Mar 2012

Theoretical Study Of The Effects Of Di-Muonic Molecules On Muon-Catalyzed Fusion, Eugene V. Sheely

Theses and Dissertations

This document presents a theoretical study di-muonic hydrogen and helium molecules that have the potential of enhancing the muon-catalyzed fusion reaction rate. In order to study these di-muonic molecules a method of non-adiabatic quantum mechanics referred to as a General Particle Orbital (GPO) method was developed. Three mechanisms that have the possibility of enhancing the muon-catalyzed fusion rate were discovered. Two involve the formation of di-muonic hydrogen molecules, and the other uses di-muonic molecules to liberate muons stuck to 3He nuclei. The effects of muon spin on dimuonic hydrogen molecules was studied. The nuclear separation in di-muonic hydrogen molecules …

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Local Histograms For Per-Pixel Classification, Melody L. Massar Mar 2012

Local Histograms For Per-Pixel Classification, Melody L. Massar

Theses and Dissertations

We introduce a rigorous mathematical theory for the analysis of local histograms, and study how they interact with textures that can be modeled as occlusions of simpler components. We first show how local histograms can be computed as a system of convolutions and discuss some basic local histogram properties. We then introduce a probabilistic, occlusion-based model for textures and formally demonstrate that local histogram transforms are natural tools for analyzing the textures produced by our model. Next, we characterize all nonlinear transforms which satisfy the three key properties of local histograms and consider the appropriateness of local histogram features in …

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Surveillance Versus Reconnaissance: An Entropy Based Model, Tamilyn S. Dismukes Mar 2012

Surveillance Versus Reconnaissance: An Entropy Based Model, Tamilyn S. Dismukes

Theses and Dissertations

With the advancing capabilities of Intelligence, Surveillance, and Reconnaissance (ISR) assets and sensors, effective utilization of these resources continues to pose a challenge to military decision makers. The methodology developed explores allocation of ISR assets while balancing detection of new targets versus surveillance of already detected targets using entropy as a Measure of Effectiveness (MOE). Scenarios with an unknown number of static and moving targets in a bounded geographical region are considered. A baseline model was built to examine four different search algorithms: random, raster, greedy, and a rollout algorithm based on dynamic programming. A space-filling Nearly Orthogonal Latin Hypercube …

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A Prototype Overview For Allocating Usaid Foreign Aid, Deane E. Cover Mar 2012

A Prototype Overview For Allocating Usaid Foreign Aid, Deane E. Cover

Theses and Dissertations

The United States Agency for International Development (USAID) is the federal government agency primarily responsible for administering civilian foreign aid. In fiscal year 2011, USAID spent approximately $15 billion in an effort to assist countries recovering from disaster, trying to escape poverty, and engaging in democratic reforms. Using Value-Focused Thinking, regression, and optimization techniques, this thesis utilizes overarching USAID objectives and underlying policy to develop a prototype overview model that is used to provide insight to a Decision Maker regarding how changes in funding allocation can lead to improved impact.

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A Simulation To Evaluate Joint Military Logistics In A Humanitarian Assistance Environment, Ryan S. Fisher Mar 2012

A Simulation To Evaluate Joint Military Logistics In A Humanitarian Assistance Environment, Ryan S. Fisher

Theses and Dissertations

Currently, no capability exists to cost-effectively simulate and measure a Joint Task Force-Port Opening (JTF-PO) operation to predict cargo throughput based on the availability of resources. The purpose of this research is to create a decision model using Arena® simulation software to provide United States Transportation Command (USTRANSCOM) decision makers the ability to predict cargo throughput in a Humanitarian Assistance/Disaster Response (HA/DR) scenario. The data used in this simulation were taken from the JTF-PO involvement in Operation UNIFIED RESPONSE, Port-au-Prince, Haiti 2010. The research uses a design of experiments approach to statistically plan and measure the throughput of cargo based …

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The Effectiveness Of Using Diversity For Selecting Multiple Classifier Systems, Harris K. Butler Mar 2012

The Effectiveness Of Using Diversity For Selecting Multiple Classifier Systems, Harris K. Butler

Theses and Dissertations

A wealth of approaches exists to perform classification of items of interest. The goal of fusion techniques is to exploit complementary approaches and merge the information provided by these methods to provide a solution superior than any single method. Associated with choosing a fusion algorithm is the choice of algorithm or algorithms that will be fused. This decision is most often referred to as ensemble selection. Historically classifier ensemble accuracy has been used to accomplish this task. More recently research has focused on creating and evaluating diversity metrics to more effectively select ensemble members. This research focuses on the use …

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Using Qr Factorization For Real-Time Anomaly Detection Of Hyperspectral Images, Kelly R. Bush Mar 2012

Using Qr Factorization For Real-Time Anomaly Detection Of Hyperspectral Images, Kelly R. Bush

Theses and Dissertations

Anomaly detection has been used successfully on hyperspectral images for over a decade. However, there is an ever increasing need for real-time anomaly detectors. Historically, anomaly detection methods have focused on analysis after the entire image has been collected. As useful as post-collection anomaly detection is, there is a great advantage to detecting an anomaly as it is being collected. This research is focused on speeding up the process of detection for a pre-existing method, Linear RX, which is a variation on the traditional Reed-Xiaoli detector. By speeding up the process of detection, it is possible to create a real-time …

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A Decision Analysis Perspective On Multiple Response Robust Optimization, Jonathan S. Findley Mar 2012

A Decision Analysis Perspective On Multiple Response Robust Optimization, Jonathan S. Findley

Theses and Dissertations

Decisions in which multiple objectives must be optimized simultaneously occur frequently in government, military, and industrial settings. One method a decision maker may use to assist in such decisions is the application of a desirability function. An informed specification of the desirability function's parameters is essential to accurately describe the decision maker's value trade-offs and risk preference. This thesis uses utility transversality to analyze the implicit trade-off and risk attitude assumptions attendant to the desirability function. The desirability function does not explicitly account for response variability. A robust solution takes not only the expected response into account, but also its …

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Automatic Target Recognition For Hyperspectral Imagery, Kelly D. Friesen Mar 2012

Automatic Target Recognition For Hyperspectral Imagery, Kelly D. Friesen

Theses and Dissertations

Automatic target detection and recognition in hyperspectral imagery offer passive means to detect and identify anomalies based on their material composition. In many combat identification approaches through pattern recognition, a minimum level of confidence is expected with costs associated with labeling anomalies as targets, non-targets or out-of-library. This research approaches the problem by developing a baseline, autonomous four step automatic target recognition (ATR) process: 1) anomaly detection, 2) spectral matching, 3) out-of-library decision, and 4) non-declaration decision. Atmospheric compensation techniques are employed in the initial steps to compare truth library signatures and sensor processed signatures. ATR performance is assessed and …

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Ballistic Flash Characterization: Penetration And Back-Face Flash, Michael J. Koslow Mar 2012

Ballistic Flash Characterization: Penetration And Back-Face Flash, Michael J. Koslow

Theses and Dissertations

The Air Force is extremely concerned with the safety of its people, especially those who are flying aircraft. Aircrew members flying combat missions are concerned with the chance that a fragment from an exploding threat device may penetrate into the airframe to possibly ignite a fire onboard the aircraft. One concern for vulnerability revolves around a flash that may occur when a projectile strikes and penetrates an aircraft's fuselage. When certain fired rounds strike the airframe, they break into fragments called spall. Spall and other fragmentation from an impact often gain enough thermal energy to oxidize the materials involved. This …

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Tanker Fuel Consolidation: Effects Of Higher Fidelity Modeling On A Resilient Plan, Jason A. Larimore Mar 2012

Tanker Fuel Consolidation: Effects Of Higher Fidelity Modeling On A Resilient Plan, Jason A. Larimore

Theses and Dissertations

The U.S. Air Force (USAF) has selected the KC-46 to begin replacing the aged KC-135 fleet. One of the major differences between the KC-46 and the KC-135 is the KC-46's ability to be refueled. This allows for tanker fuel consolidation, or the refueling of one tanker by another. The effects of this capability on the efficiency of tanker operations must be quantified and included in determining an appropriate substitution ratio between the two aircraft. This ratio will be used to plan the retirement of KC-135s as the KC-46 enters operational fielding. This study utilizes simulation to determine the efficiencies gained …

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Impact Of Decision Criteria On Federal Aviation Administration Certification Of Military Commercial Derivative Aircraft, Michael S. Low Mar 2012

Impact Of Decision Criteria On Federal Aviation Administration Certification Of Military Commercial Derivative Aircraft, Michael S. Low

Theses and Dissertations

The decision regarding whether to maintain Federal Aviation Administration certification of military commercial derivative aircraft (MCDA) can be extremely difficult due to the subjective nature of some of the associated costs and benefits. The purpose of this research is to help decision makers understand the level of impact those costs and benefits have on their decision, and how that impact may change over the life cycle of the MCDA fleet. Data regarding the various criteria involved in such decisions were collected from subject matter experts using the Delphi technique. This information was then incorporated into a decision support tool that …

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