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Articles 211 - 240 of 609
Full-Text Articles in Operational Research
An Examination Of Statistical Rigor Infused Into The Kc-46 Flight Test Program, Sean C. Ritter
An Examination Of Statistical Rigor Infused Into The Kc-46 Flight Test Program, Sean C. Ritter
Theses and Dissertations
The KC-46 program is bringing on-line the replacement aircraft for the KC-135. Although not a new development program, but rather a modification program, there are extensive plans for the flight testing of the KC-46. Recent DoD emphasis mandates the use of statistical design principles for DoD test and evaluation. This project will examine the planned flight test program for KC-46 and reconsider components of that program based on principles of statistical rigor. Of particular focus will be the reliability and maintainability aspects of the flight test program. Current methodology assumes a constant failure rate in all situations, implying that the …
Control Variates And Optimal Designs In Metamodeling, Joshua B. Meents
Control Variates And Optimal Designs In Metamodeling, Joshua B. Meents
Theses and Dissertations
At the heart of most modeling issues is a focus on variance reduction. Experimental designs are chosen based on both efficiency and a variety of variance based criteria. In many situations due to cost, time and availability issues it is beneficial to produce metamodels of simulations. Experimental designs for the region of operability are constructed to collect the simulation output required to construct representative metamodels. Independently, the method of control variates is a well established technique often employed to reduce variance in discrete event simulations. This thesis explores the variance reduction benefits that can be obtained by combining optimal experimental …
Minimization Of Collateral Damage In Airdrops And Airstrikes, Steven P. Dillenburger
Minimization Of Collateral Damage In Airdrops And Airstrikes, Steven P. Dillenburger
Theses and Dissertations
Collateral damage presents a significant risk during air drops and airstrikes, risking citizens' lives and property, straining the relationship between the United States Air Force and host nations. This dissertation presents a methodology to determine the optimal location for making supply airdrops in order to minimize collateral damage while maintaining a high likelihood of successful recovery. A series of non-linear optimization algorithms is presented along with their relative success in finding the optimal location in the airdrop problem. Additionally, we present a quick algorithm for accurately creating the Pareto frontier in the multi-objective airstrike problem. We demonstrate the effect of …
The Multiobjective Average Network Flow Problem: Formulations, Algorithms, Heuristics, And Complexity, Jeremy D. Jordan
The Multiobjective Average Network Flow Problem: Formulations, Algorithms, Heuristics, And Complexity, Jeremy D. Jordan
Theses and Dissertations
Integrating value focused thinking with the shortest path problem results in a unique formulation called the multiobjective average shortest path problem. We prove this is NP-complete for general graphs. For directed acyclic graphs, an efficient algorithm and even faster heuristic are proposed. While the worst case error of the heuristic is proven unbounded, its average performance on random graphs is within 3% of the optimal solution. Additionally, a special case of the more general biobjective average shortest path problem is given, allowing tradeoffs between decreases in arc set cardinality and increases in multiobjective value; the algorithm to solve the average …
Rough-Cut Capacity Planning In Multimodal Freight Transportation Networks, Robert B. Hartlage
Rough-Cut Capacity Planning In Multimodal Freight Transportation Networks, Robert B. Hartlage
Theses and Dissertations
A main challenge in transporting cargo for United States Transportation Command (USTRANSCOM) is in mode selection or integration. Demand for cargo is time sensitive and must be fulfilled by an established due date. Since these due dates are often inflexible, commercial carriers are used at an enormous expense, in order to fill the gap in organic transportation asset capacity. This dissertation develops a new methodology for transportation capacity assignment to routes based on the Resource Constrained Shortest Path Problem (RCSP). Routes can be single or multimodal depending on the characteristics of the network, delivery timeline, modal capacities, and costs. The …
The In-Transit Vigilant Covering Tour Problem Of Routing Unmanned Ground Vehicles, Huang Teng Tan
The In-Transit Vigilant Covering Tour Problem Of Routing Unmanned Ground Vehicles, Huang Teng Tan
Theses and Dissertations
The routing of unmanned ground vehicles for the surveillance and protection of key installations is modeled as a new variant of the Covering Tour Problem (CTP). The CTP structure provides both the routing and target sensing components of the installation protection problem. Our variant is called the in-transit Vigilant Covering Tour Problem (VCTP) and considers not only the vertex cover but also the additional edge coverage capability of the unmanned ground vehicle while sensing in-transit between vertices. The VCTP is formulated as a Traveling Salesman Problem (TSP) with a dual set covering structure involving vertices and edges. An empirical study …
Simulation Modeling And Analysis Of The Impact Of Individual Mobility Augmentee Loss At The Tanker Airlift Control Center, Megan A. Leiter
Simulation Modeling And Analysis Of The Impact Of Individual Mobility Augmentee Loss At The Tanker Airlift Control Center, Megan A. Leiter
Theses and Dissertations
The Tanker Airlift Control Center (TACC) operates as the execution arm for Air Mobility Command's Global Reach mission. The Command and Control Directorate (XOC) monitors the execution of missions tasked to the 18th Air Force. Approximately 70% of the personnel on the operations floor are considered Individual Mobility Augmentees (IMA). Adjustments in manpower, specifically the loss of IMAs, at the TACC/XOCG may impact their responsiveness to mission deviations. This research develops a discrete event simulation using a combination of SME and historical data to capture the activities of a section of the personnel on the operations floor and the potential …
A Quantitative Methodology For Vetting "Dark Network" Intelligence Sources For Social Network Analysis, James F. Morris
A Quantitative Methodology For Vetting "Dark Network" Intelligence Sources For Social Network Analysis, James F. Morris
Theses and Dissertations
Social network analysis (SNA) is used by the DoD to describe and analyze social networks, leading to recommendations for operational decisions. However, social network models are constructed from various information sources of indeterminate reliability. Inclusion of unreliable information can lead to incorrect models resulting in flawed analysis and decisions. This research develops a methodology to assist the analyst by quantitatively identifying and categorizing information sources so that determinations on including or excluding provided data can be made. This research pursued three main thrusts. It consolidated binary similarity measures to determine social network information sources' concordance and developed a methodology to …
Using Vft As A Constraint For Goal Programming Models: A Case Study For Turkish Air Force Flying Hour Program, Ahmet Bengoz
Using Vft As A Constraint For Goal Programming Models: A Case Study For Turkish Air Force Flying Hour Program, Ahmet Bengoz
Theses and Dissertations
In its 60-year history, there have been many published documents in the literature about goal programming (GP), but contributions to the literature are still needed. This research intends to add to the literature on goal-programming models by discussing one of the key assumptions of GP regarding linearity, and by discussing some of the issues regarding incommensurability (difference in data types) and weighting. GP requires an interaction between the decision maker (DM) and the analyst to ensure that the model reflects the DM's preferences. However, it may be difficult for them to interact if the mathematical model is very large and …
A Decision Analysis Perspective On Multiple Response Robust Optimization, Jonathan S. Findley
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 …
Surveillance Versus Reconnaissance: An Entropy Based Model, Tamilyn S. Dismukes
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 …
The Effectiveness Of Using Diversity For Selecting Multiple Classifier Systems, Harris K. Butler
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 …
Using Hybrid Simulation/Analytical Queueing Networks To Capacitate Usaf Air Mobility Command Passenger Terminals, Meredithe A. Jessup Ii
Using Hybrid Simulation/Analytical Queueing Networks To Capacitate Usaf Air Mobility Command Passenger Terminals, Meredithe A. Jessup Ii
Theses and Dissertations
The objective of this study is to model operations at an airport passenger terminal to determine the optimal service capacities at each station given estimated passenger flow patterns and service rates. The central formulation is an open Jackson queueing network that can be applied to any USAF Air Mobility Command (AMC) terminal regardless of passenger type mix and flow data. A complete methodology for analyzing passenger flows and queue performance of a single flight is produced and then embedded in a framework to analyze the same for multiple departing flights. Queueing network analysis (QNA) is used because no special software …
Modeling Small Unmanned Aerial System Mishaps Using Logistics Regression And Artificial Neural Networks, Sean E. Wolf
Modeling Small Unmanned Aerial System Mishaps Using Logistics Regression And Artificial Neural Networks, Sean E. Wolf
Theses and Dissertations
A dataset of 854 small unmanned aerial system (SUAS) flight experiments from 2005-2009 is analyzed to determine significant factors that contribute to mishaps. The data from 29 airframes of different designs and technology readiness levels were aggregated. 20 measured parameters from each flight experiment are investigated, including wind speed, pilot experience, number of prior flights, pilot currency, etc. Outcomes of failures (loss of flight data) and damage (injury to airframe) are classified by logistic regression modeling and artificial neural network analysis. From the analysis, it can be concluded that SUAS damage is a random event that cannot be predicted with …
Identification And Classification Of Player Types In Massive Multiplayer Online Games Using Avatar Behavior, Earl M. Bednar
Identification And Classification Of Player Types In Massive Multiplayer Online Games Using Avatar Behavior, Earl M. Bednar
Theses and Dissertations
The purpose of our research is to develop an improved methodology for classifying players (identifying deviant players such as terrorists) through multivariate analysis of data from avatar characteristics and behaviors in massive multiplayer online games (MMOGs). To build our classification models, we developed three significant enhancements to the standard Generalized Regression Neural Networks (GRNN) modeling method. The first enhancement is a feature selection technique based on GRNNs, allowing us to tailor our feature set to be best modeled by GRNNs. The second enhancement is a hybrid GRNN which allows each feature to be modeled by a GRNN tailored to its …
Modeling And Analysis Of High Energy Laser Weapon System Performance In Varying Atmospheric Conditions, Megan P. Melin
Modeling And Analysis Of High Energy Laser Weapon System Performance In Varying Atmospheric Conditions, Megan P. Melin
Theses and Dissertations
This thesis addresses two primary concerns relating to Directed Energy (DE) models and tests: need for more use of Design of Experiment (DOE) in structuring DE models and tests, and lack of modeling atmospheric variability in High Energy Laser (HEL) weapon system propagation models and tests. To address these concerns we use a DOE factorial design to capture main, interaction, and non-linear effects between modeled weapon design and environmental factors in a well defined simulated Air-to-Ground HEL engagement scenario. The scenario modeled considers a B1-B aircraft in the 2022 timeframe equipped with an HEL weapon, irradiating a ground target from …
Face Recognition Via Ensemble Sift Matching Of Uncorrelated Hyperspectral Bands And Spectral Pcts, Mohd Fairul Mohd-Zaid
Face Recognition Via Ensemble Sift Matching Of Uncorrelated Hyperspectral Bands And Spectral Pcts, Mohd Fairul Mohd-Zaid
Theses and Dissertations
Face recognition is not a new area of study, but facial recognition using through hyperspectral images is a somewhat new concept which is still in its infancy. Although the conventional method of face recognition using Red-Green-Blue (RGB) or grayscale images has been advanced over the last twenty years, these methods are still shown to have weak performance whenever there are variations or changes in lighting, pose, or temporal aspect of the subjects. A hyperspectral representation of an image captures more information that is available within a scene than a RGB image therefore it is beneficial to study the performance of …
Utilizing Social Network Analysis In Support Of Nation Building, Brandon J. Bernardoni
Utilizing Social Network Analysis In Support Of Nation Building, Brandon J. Bernardoni
Theses and Dissertations
Social network analysis is a powerful set of techniques used by social scientists to study the formal and informal interrelations in a community. Since 9/11 these techniques have been increasingly utilized by the defense and intelligence communities to analyze terrorist networks to aid in thwarting our foes. This study investigates the use of social networks and structural holes to facilitate nation building in failed and failing states. Investigation of the underlying social structure of a community, identifying st ructural holes and gaps within the government, Security Stabilization Transition and Reconstruction Operations (SSTRO) efforts can be focused to strengthen the host …
Determining Pilot Manning For Bomber Longevity, Jason S. Hamilton
Determining Pilot Manning For Bomber Longevity, Jason S. Hamilton
Theses and Dissertations
In support of US Air Force efforts to conserve resources without sacrificing capability, this research examines the question of whether the 509th Bomb Wing could continue to provide maximum combat capability with fewer assigned pilots. During peacetime, pilot proficiency training comprises the majority of annual flying hours for the small B-2 bomber fleet. Optimal pilot manning will decrease the accumulation of excess wear on the airframes; helping to extend the viable life of the B-2 fleet and preserve the deterrent and combat capabilities that it provides to the United States. The operations and maintenance activity flows for B-2 aircraft and …
A Methodology Using Simulation Results For Test And Evaluation, Jonathon S. Hosket
A Methodology Using Simulation Results For Test And Evaluation, Jonathon S. Hosket
Theses and Dissertations
Each year the Air Force spends billions of dollars on Test and Evaluation to ensure acquisition programs roll out the best possible products. In 1997, the National Research Council assembled to evaluate the overall procedure used in procuring various platforms with system planning, research, development and engineering (SPRDE) and program management (PM) processes. In their final report, they claimed that the full advantages of statistical practices, simulation, model-test-models, and incorporation of prior test information into current test practices have not been fully utilized. To examine one of the report's recommendations, this thesis defines and explores a methodology using simulation to …
Measure Of Effectiveness For Jstars Ground Moving Target Indicator: A Value Focused Thinking Approach, Gardner J. Joyner
Measure Of Effectiveness For Jstars Ground Moving Target Indicator: A Value Focused Thinking Approach, Gardner J. Joyner
Theses and Dissertations
As the nature of warfare has shifted from a conventional approach to more guerilla type warfare, intelligence has become more important than at any other time in the history of the United States Military. With the stochastic nature of intelligence gathering, it is almost impossible to know with any degree of certainty where and when the next piece of information that could possibly change the course of the battle or war will be obtained. US intelligence gathering assets have long been plagued with using useless measures of performance rather than measures of effectiveness to determine their worth. This research uses …
Weighted Key Player Problem For Social Network Analysis, Ryan M. Mcguire
Weighted Key Player Problem For Social Network Analysis, Ryan M. Mcguire
Theses and Dissertations
Social network analysis is a tool set whose uses range from measuring the impact of marketing campaigns to disrupting clandestine terrorist organizations. Social network analysis tools are primarily focused on the structure of relationships between actors in the network. However, characteristics of the actors, such as importance or status, are generally the output of the social network analysis rather than an input. Characteristics of actors can come from a number of sources to include information gathering, subject matter experts or social network analysis. Further, the strength of relationships between actors in social networks are often assumed to be all equal. …
Contextual Detection Of Anomalies In Hyperspectral Images, Adam J. Messer
Contextual Detection Of Anomalies In Hyperspectral Images, Adam J. Messer
Theses and Dissertations
The majority of anomaly detectors in Hyperspectral Imaging use only the statistical aspects of the spectral readings in the image. These detectors fail to use the spatial context that is contained in the images. The use of this information can yield detectors that out perform their spatially myopic counterparts. To demonstrate this, we will use an independent component analysis based detector, autonomous global anomaly detector (AutoGAD), developed at AFIT augmented to account for the spatial context of the detected anomalies. Through the use of segmentation algorithms, the anomalies identified are formed into regions. The size and shape of these regions …
Decision Analysis And Validation Of Value Focused Thinking Decision Models Using Multivariate Analysis Techniques, James L. Pruitt
Decision Analysis And Validation Of Value Focused Thinking Decision Models Using Multivariate Analysis Techniques, James L. Pruitt
Theses and Dissertations
Decision Analysis (DA) is a useful tool to assist decision makers (DM) with difficult and complex decisions using mathematical models. Value Focused Thinking (VFT) models are a useful DA tool widely employed in the Air Force. However, VFT models are rarely validated. This research will attempt to validate any given VFT model and provide insight into the discriminating attributes of the alternative set. First, a two group discriminant analysis is applied the alternative set given the prior knowledge of the selected alternatives. Next, compromise programming is used attempt to minimize the distance between the posterior probability of an alternative being …
Determining The Value Of Future Information, James J. Springston
Determining The Value Of Future Information, James J. Springston
Theses and Dissertations
Companies continuously struggle to quantify the value of their information in an attempt to gain a better understanding of the return on investment of their information technology (IT) architecture. One approach companies have taken to place a numeric value on information is to treat it as a traditional economic asset (e.g. equipment, buildings, and vehicles) that is governed by its own unique set of laws. Once an enterprise understands the behavior of information it can incorporate Skyrme's "10 value adding aspects of information" when developing IT architecture, thus maximizing the potential value of their information. Like most enterprises, the Intelligence …
Migration Issues In The Democratic Republic Of Congo, Michael J. Thompson
Migration Issues In The Democratic Republic Of Congo, Michael J. Thompson
Theses and Dissertations
Since the end of the Cold War, the number of weak and failing states has increased significantly. The United States (US) military has been deployed in multiple nation states in an effort to prevent these weak states from collapsing into chaos. This thesis explores one of the driving factors of state collapse, net migration, to gauge how US foreign policy might be employed to reduce the flow of people out of a country. To demonstrate the foreign policies and their effects, a pilot model was constructed using a system dynamics methodology. The Democratic Republic of Congo (DRC) was selected as …
Fusion Schemes For Ensembles Of Hyperspectral Anomaly Detection Algorithms, Brooks R. Turnquist
Fusion Schemes For Ensembles Of Hyperspectral Anomaly Detection Algorithms, Brooks R. Turnquist
Theses and Dissertations
Hyperspectral imaging is playing an ever increasing role in our military's remote sensing operations. The exponential increase in collection operations generates more data than can be evaluated by analysts unassisted. Anomaly detectors attempt to reduce this load on analysts by identifying potential target pixels which appear anomalous when compared to what are determined to be background, or non-target, pixels. However, there is no one individual algorithm that is best suited for all situations and it can be difficult to choose the best algorithm for each individual task. Fusion techniques have been shown to reduce errors and increase generalization, eliminating the …
Empirical Characterization Of Ballistic Impact Flash, Thomas P. Talafuse
Empirical Characterization Of Ballistic Impact Flash, Thomas P. Talafuse
Theses and Dissertations
Fires onboard aircraft are leading mechanisms for mishaps and losses during peacetime and combat operations. Typical ignition sources causing fires onboard aircraft include electrical sparks and hot surfaces. However, impact and penetration of common threats encountered during combat operations, such as armor piercing incendiary projectiles and missile fragments, generate short-lived, but thermally-intense clouds (flashes) capable of igniting fires. Fire simulations supporting system-level survivability analyses depend on accurate characterization of these flash clouds, however, such accurate representations are not currently available. This research presents the modeling approach developed to estimate the boundary model representations of impact flashes. The research presents generalized …
Optimizing Ground Times For Amc Aircraft In Afghanistan, Eric W. Bucheit Jr.
Optimizing Ground Times For Amc Aircraft In Afghanistan, Eric W. Bucheit Jr.
Theses and Dissertations
This research provides insight into the cargo unloading and loading process and times at three airfields in Afghanistan. Using a linear regression model and its prediction capability, a more stabilized environment is produced. This uses the times from seven historical months of continuous operations in Afghanistan and uses this information for the prediction expressions. Using this model, no throughput is lowered and early and late times are lowered by an average of seven minutes per mission. Over the course of a month, this increases planning stability by 74.1 hours. This not only impacts the planning at the downrange location, but …
Optimal Ch-47 And C-130 Workload Balance, Dustin P. Jones
Optimal Ch-47 And C-130 Workload Balance, Dustin P. Jones
Theses and Dissertations
The Air Force can save thousands of dollars by reducing the number of blade hours on the CH-47 through finding an optimal mixture of CH-47s and C-130s to conduct current operations in Afghanistan and Iraq. Ultimately these savings will relieve maintenance operations for the CH-47 and lengthen the lifespan of the CH-47 airframe. Moreover, incorporating C-130s into the operations will reduce cargo transit time from supply depots. This study looks at the involvement of the C-130 in CH-47 airlift operations to reduce CH-47 usage and increase supply efficiency. The research focus is narrowed to current airlift operations in Afghanistan and …