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Full-Text Articles in Engineering

Computer-Based Methods For Constructing Two-Level Fractional-Factorial Experimental Designs With A Requirement Set, Steven L. Forsythe Dec 2000

Computer-Based Methods For Constructing Two-Level Fractional-Factorial Experimental Designs With A Requirement Set, Steven L. Forsythe

Theses and Dissertations

This dissertation developed four methodologies for computer-aided experimental design of two-level fractional factorial designs with requirement sets (DOE/RS). The requirement sets identify all the experimental factors and the appropriate interaction terms to be evaluated in the experiment. Taguchi graphs and similar manual methods provide techniques for solving the DOE/RS problem. Unfortunately, these methods are limited because they become difficult to use as the number of factors or interaction terms exceeds ten. This research showed that the DOE/RS problem belongs to a class of difficult-to-solve problems known as NP-Complete. It is the combinatorial nature of NP-Complete problems that causes them to …


Estimating Budget Relationships With A Leontief Input-Output Model, Guenever L. R. Shariff Dec 2000

Estimating Budget Relationships With A Leontief Input-Output Model, Guenever L. R. Shariff

Theses and Dissertations

Forty years ago, the Office of the Secretary of Defense proposed using the Leontief input-output model to assess tradeoffs in the Department of Defense's (DoD) budget. We demonstrate that the Leontief input-output model can assess tradeoffs in the Air Force's budget. To increase one part of the Air Force's budget, we need to know the interrelationships between that budget area and the other areas. In this research, we look at different methods of how the functional areas might interact. We demonstrate our methodology on two data sets - DoD and the Air Force aggregate budget data. By looking at how …


Covalidation Of Dissimilarly Structured Models, Samuel A. Wright Dec 2000

Covalidation Of Dissimilarly Structured Models, Samuel A. Wright

Theses and Dissertations

A methodology is presented which allows comparison between models constructed under different modeling paradigms. Consider the following situation: Two models are constructed to study different aspects of the same system. One model simulates a fleet of aircraft moving a given combination of cargo and passengers from an onload point to an offload point. A second model is a linear programming model that optimizes the aircraft and route selection required for the same scenario. We develop a methodology to structure the comparison between large-scale models such as these. Models that compare favorably using this methodology are deemed covalid. Models that perform …


Simulation Evaluation Of The Combat Value Of A Standoff Precision Airdrop Capability, Michael W. Varner Mar 2000

Simulation Evaluation Of The Combat Value Of A Standoff Precision Airdrop Capability, Michael W. Varner

Theses and Dissertations

This project is a simulation evaluation of the developmental standoff precision airdrop (SOPAD) capability. SOPAD is a new technology under consideration to deliver supplies to forward-deployed units using either a semi-rigid wing or a guided parafoil. These delivery systems allow airdrop of supplies from altitudes of 25,000 feet and distances 25 miles from the delivery point. Using global positioning system guidance, on board navigational computers, and automatic steering mechanisms, the delivery system flies to the target following a designated flight plan. The concept includes delivering supplies to remote and potentially hostile areas without endangering the supply aircraft. In addition, supplies …


A Java Universal Vehicle Router In Support Of Routing Unmanned Aerial Vehicles, Robert W. Harder Mar 2000

A Java Universal Vehicle Router In Support Of Routing Unmanned Aerial Vehicles, Robert W. Harder

Theses and Dissertations

Unmanned Aerial Vehicles (UAVs) help the military gather information in times of peace and war. During a mission, typically 100 sites or more, a UAV will frequently be re-tasked to visit a pop-up threat, leaving the operator to determine the best way to finish the day's list of sites after the re-tasking. I develop a prototype application to serve the needs of a specific customer, the 11th Reconnaissance Squadron, by helping them preplan missions and dynamically re-task UAVs. This prototype application is built on a reusable airframe router called the core AFIT Router, which can later be added to more …


The Distributor’S Three-Dimensional Pallet-Packing Problem: A Mathematical Formulation And Heuristic Solution Approach, Brian P. Ballew Mar 2000

The Distributor’S Three-Dimensional Pallet-Packing Problem: A Mathematical Formulation And Heuristic Solution Approach, Brian P. Ballew

Theses and Dissertations

It is through practice and experience Air Force loadmasters are able to pack the Air Force standard HCU-6/E (463L) pallets efficiently. Although the loadmasters perform their jobs exceptionally well, the Air Force is in search of a model that will more efficiently pack the pallets. We have developed a mathematical formulation of the three-dimensional pallet-packing problem which minimizes the amount of unused space on a pallet. The formulation ensures each box is packed with the correct volume and dimensions, and ensures the volume of all the boxes packed is less than the available pallet volume. Additionally, the formulation ensures that …


Locating Search And Rescue Stations In The Aegean And Western Mediterranean Regions Of Turkey, Melih M. Basdemir Mar 2000

Locating Search And Rescue Stations In The Aegean And Western Mediterranean Regions Of Turkey, Melih M. Basdemir

Theses and Dissertations

The service of present Search and Rescue (SAR) stations in the Aegean and the Western Mediterranean regions of Turkey are not sufficient to meet the demands of the Turkish Air Force. This research seeks to find the optimum location of new SAR stations. The number of SAR stations required to cover all areas of operation becomes a very decisive element in finding the optimal coverage of the operation area by these stations. The problem of finding the optimum SAR locations can he modeled as a maximal covering location problem (MCLP). Additional constraints are added to set standards on various issues …


A Combined Inventory And Delivery Model For Repairable Items, Bahtiyar Eren Mar 2000

A Combined Inventory And Delivery Model For Repairable Items, Bahtiyar Eren

Theses and Dissertations

Traditionally, logistics analysts have treated the delivery problem separate from the inventory and repair problems. In other words, each of these three problems-delivery, inventory, and repair-are treated individually. We combine the vehicle routing problems and inventory allocation problems in a single formulation. Furthermore, lateral re-supply is considered, in that supplies are not only available from the main depot, but also from other bases. After we get the lateral re-supply information, we set a delivery allocation plan out of the main depot. Such allocations are then delivered via vehicles stationed at the main depot. There is a repair capability for each …


Global Positioning System (Gps) Error Source Prediction, Marcus G. Ferguson Mar 2000

Global Positioning System (Gps) Error Source Prediction, Marcus G. Ferguson

Theses and Dissertations

With the initiation of the navigation accuracy prediction algorithm used to estimate the amount of GPS solution (location and time) error for receivers, the capability to accurately predict solution errors due to the major GPS error sources is growing. Although some sources of error within the GPS solution have been previously analyzed, modeled, and/or accounted for within various modeling efforts, a formal evaluation of the seven major error sources that distort GPS activity has not been officially conducted up until this point. This research offers a logical assessment of all the major GPS error sources and their definitive impact on …


A Group Theoretic Tabu Search Approach To The Traveling Salesman Problem, Shane N. Hall Mar 2000

A Group Theoretic Tabu Search Approach To The Traveling Salesman Problem, Shane N. Hall

Theses and Dissertations

The traveling salesman problem (TSP) is a combinatorial optimization problem that is mathematically modeled as a binary integer program. The TSP is a very important problem for the operations research academician and practitioner. This research demonstrates a Group Theoretic Tabu Search (GTTS) Java algorithm for the TSP. The tabu search metaheuristic continuously finds near-optimal solutions to the TSP under various different implementations. Algebraic group theory offers a more formal mathematical setting to study the TSP providing a theoretical foundation for describing tabu search. Specifically, this thesis uses the Symmetric Group on n letters, S(n), which is the set of all …


Toward Validating Vertical Aggregation In Object Oriented Simulation, George W. Johnson Jr. Mar 2000

Toward Validating Vertical Aggregation In Object Oriented Simulation, George W. Johnson Jr.

Theses and Dissertations

Recent interest in studying the nonlinear effects of intelligence, surveillance, and reconnaissance in combat models has prompted researchers to employ vertical aggregation in object-oriented simulations. Traditional horizontal aggregation falls short for its inability to provide accurate means for nonlinear functions. Averaging a group of objects that exhibit nonlinear behavior provides a linear approximation to the mean, which is not necessarily the expected value of the underlying nonlinear function. Vertical aggregation explicitly models individual objects, thus preserving their nonlinear behaviors. In this research, a validation procedure is derived to study the aptness of vertical aggregation methods. Validation is carried out by …


Using Simulation To Model An Army Recruiting Station With Seasonality Effects, David C. Longhorn Mar 2000

Using Simulation To Model An Army Recruiting Station With Seasonality Effects, David C. Longhorn

Theses and Dissertations

One of the toughest jobs in the Army is that of the recruiter. Recruiters are tasked with the awesome job of convincing young men and women to lay down their lives and freedoms for their country, and oftentimes for less money than can be earned in the safer environment of America's booming economy. Recruiters face enormous pressure from commanders to meet the mandated Army manning levels set each year by Congress. As the Army begins the 21st century, it is faced with having to support an increasing number of deployments with fewer soldiers. Soldiers face long and difficult days with …


Leontief Metamodeling For Military Strategic Effects, Anthony W. Snodgrass Mar 2000

Leontief Metamodeling For Military Strategic Effects, Anthony W. Snodgrass

Theses and Dissertations

In this research, we propose and demonstrate an approach to incorporate currently un-modeled interactions into an existing or a new combat model or simulation. We apply the Leontief Input-Output model, which is a macro-economic model that measures the interactions between major industrial sectors of an economy, as a metamodel that periodically assesses the status of various combat units and support functions. If needed resources are insufficient, appropriate degrades are input into the combat model. As a result, dependencies that are not in the combat model are incorporated. Hence, we can assess the strategic or cascading effects of destroying a set …


Robust Multi-Scenario Optimization Of An Air Expeditionary Force Force Structure Applying Genetic Algorithms To The Combat Forces Assessment Model, Barry D. Bennett Jr. Mar 2000

Robust Multi-Scenario Optimization Of An Air Expeditionary Force Force Structure Applying Genetic Algorithms To The Combat Forces Assessment Model, Barry D. Bennett Jr.

Theses and Dissertations

The United States Air Force is increasingly facing more diverse threat situations while existing force structure levels are being reduced and proposed compositions are being severely scrutinized for relevance, affordability, and effectiveness. Military planners are struggling with the question of how to generate a single force structure that can adequately respond to a multitude of threat scenarios in an uncertain future while at the same time being tasked to prove just how effective their choice will be. In the past, modeling has been effective in showing how a force can respond to a single threat scenario but a new modeling …


Using Rsm, Doe, And Linear Regression To Develop A Metamodel To Predict Cargo Delivery Of A Time Phase Force Deployment Document, Kenneth S. Browne Mar 2000

Using Rsm, Doe, And Linear Regression To Develop A Metamodel To Predict Cargo Delivery Of A Time Phase Force Deployment Document, Kenneth S. Browne

Theses and Dissertations

Air Mobility Command (AMC) uses the Airlift Flow Model as their primary tool to estimate the amount of cargo delivered in a Time Phase Force Deployment Document (TPFDD). The primary objective of this research was an exploratory investigation in the development of a metamodel to predict the amount of cargo delivered from a TPFDD by AMC into a theater. In creating a valid metamodel the analyst would be able to quickly provide the decision-maker with accurate insights should input parameters change. This would save valuable time and replace the need to physically change the input parameters and re-run the simulation. …


A Tabu Search Metaheuristic For The Air Refueling Tanker Assignment Problem, Shay R. Capehart Mar 2000

A Tabu Search Metaheuristic For The Air Refueling Tanker Assignment Problem, Shay R. Capehart

Theses and Dissertations

In a joint effort between Air Mobility Command (AMC) and the Air Force Institute of Technology, we present a Tanker Assignment Problem (TAP) Tool capable of providing tanker mission plans for deployment scenarios. Due to the complex nature of extracting a mission plan from the Combined Mating and Ranging Planning System (CMARPS), AMC requires a tool to provide similar results in a simpler and less time consuming manner. The tool developed allows AMC to input several receiver groups consisting of various aircraft types and numbers. Each receiver group contains a point of origin and destination, with the option of providing …


Feature Selection For Predicting Pilot Mental Workload, Julia A. East Mar 2000

Feature Selection For Predicting Pilot Mental Workload, Julia A. East

Theses and Dissertations

Advances in technology have the cockpits of the aircraft in the Air Force inventory increasingly complex. Consequently, mental demands on the pilot have risen. In some cases, mental demands were so overwhelming that pilots have forgotten basic flying techniques, such as G-straining maneuvers. The results have been fatal. Recent research in this area has involved collecting psychophysiological features, such as electroencephalography (EEG), heart, eye and respiration measures, in an attempt to identify pilot mental workload. This thesis focuses on feature selection and reduction of the psycophysiological features and subsequent classification of pilot mental workload on multiple subjects over multiple days. …


A Hybrid Jump Search And Tabu Search Metaheuristic For The Unmanned Aerial Vehicle (Uav) Routing Problem, Gary W. Kinney Jr. Mar 2000

A Hybrid Jump Search And Tabu Search Metaheuristic For The Unmanned Aerial Vehicle (Uav) Routing Problem, Gary W. Kinney Jr.

Theses and Dissertations

In this research, we provide a new meta-heuristic, a jump search I tabu search hybrid, for addressing the vehicle routing problem with real-life constraints. A tour construction heuristic creates candidate solutions or jump points for the problem. A tabu search algorithm uses these jump points as starting points for a guided local search. We provide statistical analysis on the performance of our algorithm and compare it to other published algorithms. Our algorithm provides solutions within 10% of the best known solutions to benchmark problems and does so in a fraction of the time required by competing algorithms. The timeliness of …


The Evaluation Of Competing Classifiers, Stephen G. Alsing Mar 2000

The Evaluation Of Competing Classifiers, Stephen G. Alsing

Theses and Dissertations

This dissertation research makes contributions towards the objective evaluation of competing classifiers, i.e., classification systems (CSs) or pattern recognition algorithms. Automatic CSs have been under development for almost 40 years in a wide range of military and medical applications. During this period, scientists and engineers have developed extensive theory and algorithms for classification, but by comparison have focused little on the testing and evaluation of their systems. Classifier evaluation is very important in the fields of automatic target recognition (ATR) and pilot workload classification. In order for military operators to be confident in new CSs, they must have an objective …


Hierarchical Interactive Theater Model (Hitm): An Investigation Into The Relationship Between Strategic Effects And Ooda Loops, Richard K. Bullock Mar 2000

Hierarchical Interactive Theater Model (Hitm): An Investigation Into The Relationship Between Strategic Effects And Ooda Loops, Richard K. Bullock

Theses and Dissertations

Airpower's strength lies in being able to quickly strike the enemy directly where they are vulnerable while being unhampered by geography and surface forces. Airpower theory suggests the effects of these strikes propagate throughout an opponent1s military system yielding catastrophic output or strategic effects. Despite this theory being a cornerstone of US Air Force doctrine, current Air Force models do not seem to capture airpower's inherent strength. Since these models are used to support budgetary decision making, the United States may not be funding the airpower capability it needs.


A Decision Support Tool To Aid Campaign Planners In Selecting Combat Aircraft For Theater Crisis, Christopher D. Buzo Mar 2000

A Decision Support Tool To Aid Campaign Planners In Selecting Combat Aircraft For Theater Crisis, Christopher D. Buzo

Theses and Dissertations

One way of comparing alternative deployment plans is to examine how combat aircraft tasked within a deployment plan meet the combat commander's requirements. Both the absolute capabilities and the campaign-specific issues affecting the operational capabilities of those aircraft could assess a set of combat aircraft, unique to a deployment plan. This research-develops a non-absolute, campaign-specific decision Support tool to assess the effect of campaign-specific issues on a set of deployable Air Force combat aircraft. This research is conducted in three phases. Cognitive Task Analysis (CTA) and Multi-Attribute Preference Theory (MAPT) methodologies are applied to in-person and telephone interviews with subject …


An Incentive Model For International Telecommunications, Jeffrey R. Del Vecchio Mar 2000

An Incentive Model For International Telecommunications, Jeffrey R. Del Vecchio

Theses and Dissertations

This study developed a new defensive model for global voice communications. It uses a n-person, zero-sum, cooperative and non-cooperative game to optimize the coalitions revenue after the possibility of a network service provider being tampered by an adversary. This research optimized two measures of effectiveness (coalition revenue and network provider revenue) of international telecommunications coalitions by hardening network service providers and improving their respective revenue with incentives. A multi-criteria optimization problem was developed to establish the strategic competition between the coalition defender and attacker. Irrespective of the amount of incentives, a applicable hardening and tampering strategy can be obtained. All …


Multi-Objective Evaluation Of Target Sets In A Logistics Network, Paul D. Emslie Mar 2000

Multi-Objective Evaluation Of Target Sets In A Logistics Network, Paul D. Emslie

Theses and Dissertations

This thesis addresses the selection of target sets to disrupt an adversary's logistics network in a wartime environment. In the presence of many objectives--such as reducing maximum flow, lengthening routes, avoiding collateral damage, all at minimal risk to our pilots--the problem of determining the best target set is complex. Previous efforts have not adequately considered the value of the remaining network functionality after target destruction. In addition, current network targeting procedures optimize target sets with respect to only a single metric. This thesis uses a multi-objective decision analysis framework capturing actual targeting decision-maker values and preferences to evaluate and analyze …


Modelling Information Assurance: A Value Focused Thinking Approach, Jonathan Todd Hamill Mar 2000

Modelling Information Assurance: A Value Focused Thinking Approach, Jonathan Todd Hamill

Theses and Dissertations

The information revolution has brought forth new and improved capabilities to rapidly disseminate and employ information in decision-making. These capabilities are critical to the civilian and military infrastructures of the United States, and act as force enhancers and enablers for the Armed Forces. These capabilities, however, often rely upon systems interconnected throughout the world, resulting in potentially increased vulnerability to attack. To add to this problem, elusive, threatening forces (national and transnational) originating from anywhere on the globe are likely to offer opponents less reliant on information technology an asymmetric advantage over information-reliant nations like the United States. To date, …


A Validation Assessment Of The Storm Air-To-Air Prototype Algorithm, David M. Pugh Mar 2000

A Validation Assessment Of The Storm Air-To-Air Prototype Algorithm, David M. Pugh

Theses and Dissertations

A validation assessment of the new STORM air-to-air prototype algorithm is accomplished using structural and output validation techniques. In the structural validation phase, the algorithms, code, and assumptions are evaluated to determine if the implementation of the model will match the intent of the designers. The components of the algorithm are compared to its predecessor, THUNDER, to evaluate if the prototype nnproves upon the weaknesses of THUNDER. In the output validation phase, the results of the model are evaluated to determine the extent to which the implementation of the model matches expected outcomes. Sensitivity analysis is presented to provide insight …


A Greedy Multiple-Knapsack Heuristic For Solving Air Mobility Command’S Intratheater Airlift Problem, Nicholas J. Zeisler Mar 2000

A Greedy Multiple-Knapsack Heuristic For Solving Air Mobility Command’S Intratheater Airlift Problem, Nicholas J. Zeisler

Theses and Dissertations

This research develops a methodology using a greedy heuristic to solve Air Mobility Command's intratheater airlift scenario as a multiple knapsack problem. The objective is to maximize throughput in a theater given a vehicle mixture and assignment scheme. The model allows for a heterogeneous, user defined vehicle mix in a theater consisting of up to five bed down locations and up to seven forward operating locations. First, we preprocess routes, eliminating the large number of unattractive route choices in the problem. Then using a greedy heuristic, we select routes and assign them to aircraft located at any or all of …