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Full-Text Articles in Engineering

How To Develop An Interactive Electronic Technical Manual: An Industry Perspective, Ali N. Karabulut, Hilmi Oz Dec 1998

How To Develop An Interactive Electronic Technical Manual: An Industry Perspective, Ali N. Karabulut, Hilmi Oz

Theses and Dissertations

Improvements in technology, especially in computer science, in the last two decades have made it possible, and preferable to develop digital technical manuals. A digital manual, which is called an Interactive Electronic Technical Manual (IETM), is a package of information required for the diagnosis and maintenance of a weapon systems, optimally arranged and formatted for interactive screen presentation to the end-user. Being the largest organization in the U.S., the Department of Defense has pioneered in the development of IETM concept as well as in the establishment of its standards. There have been many researches done about different IETM applications and …


Feature Saliency In Artificial Neural Networks With Application To Modeling Workload, Kelly A. Greene Dec 1998

Feature Saliency In Artificial Neural Networks With Application To Modeling Workload, Kelly A. Greene

Theses and Dissertations

This dissertation research extends the current knowledge of feature saliency in artificial neural networks (ANN). Feature saliency measures allow for the user to rank order the features based upon the saliency, or relative importance, of the features. Selecting a parsimonious set of salient input features is crucial to the success of any ANN model. In this research, several methodologies were developed using the Signal to Noise Ratio (SNR) Feature Screening Method and its associated SNR Saliency Measure for selecting a parsimonious set of salient features to classify pilot workload in addition to air traffic controller workload. Candidate features were derived …


Development Of An Operations Research Software Package For Army Divisions., Blane C. Wilson Dec 1998

Development Of An Operations Research Software Package For Army Divisions., Blane C. Wilson

Theses and Dissertations

There exists great potential for applying operations research techniques to solve specific problems in the areas of operations, installation support, and training at the Army division level. Because of the operational tempo of today's active-duty and reserve component units, command must focus on accomplishing the daily missions. Also, due their limited knowledge of the field, planners may not be aware of how operations research can be used to enhance planning and operations. Time, training funds, resources, safety, personnel, and equipment are all critical factors in this process. Operations research techniques could be used to improve division-level operations by saving time, …


An Integer Program Decomposition Approach To Combat Planning, John C. Van Hove Sep 1998

An Integer Program Decomposition Approach To Combat Planning, John C. Van Hove

Theses and Dissertations

Over the last two decades, our military forces have been working to incorporate the latest computer technology into the combat planning process. The earliest efforts use word processors, spreadsheets, and databases to organize planning data and to display high level summaries for commanders. Later efforts perform feasibility checks as missions are planned to insure that the necessary resources are available and that the assets requested are capable of meeting the assigned scheduling requirements. Some of the most recent computer planning tools have included the capability to automatically plan individual missions or groups of missions. These automated efforts have been heuristic …


Data Storage Devices For Air Force Space Command: A Comparative Analysis, Darryl E. Mosley Sep 1998

Data Storage Devices For Air Force Space Command: A Comparative Analysis, Darryl E. Mosley

Theses and Dissertations

Two of Air Force Space Command's primary missions are ballistic missile warning and global navigation, accomplished by commanding and controlling Defense Support Program and Global Positioning System satellites respectively. The computerized ground control system, called the satellite command and control system (CCS) used to perform command and control of the satellites currently uses antiquated peripheral storage devices. These storage devices are critical components, but are often prone to failure, possibly resulting in adverse mission impact. The Air Force must choose an alternative storage device for use in conjunction with CCS in order to accommodate planned operations tempo increases. This thesis …


Feasibility Study On The Use Of The Internet For Traffic Of Unclassified Data, Alexandre L. Guerra, Luiz Gustavo F. P. Silva Sep 1998

Feasibility Study On The Use Of The Internet For Traffic Of Unclassified Data, Alexandre L. Guerra, Luiz Gustavo F. P. Silva

Theses and Dissertations

This research compares two possible networking methods for connecting all Brazilian Air Force Materiel Command units responsible for support and operation of Brazilian Air Force's weapons systems. The network includes the use of dedicated X.25 links, and the use of a virtual Private Network using the Internet (TCP/IP) as the medium of transmission. The Brazilian Air Force Materiel Command, responsible to support operating units over a very large sparse territory, lacks an efficient media of computer communications, which makes it difficult to control the supply chain channels of materiel present in each unit, depots, and warehouses. We studied the network …


Analysis Of Usaf Medium And Heavylift Space Launch Mission Reliability Requirements, Arthur R. Dawkins Sep 1998

Analysis Of Usaf Medium And Heavylift Space Launch Mission Reliability Requirements, Arthur R. Dawkins

Theses and Dissertations

The launch services that the USAF procures to carry DOD payloads into orbit are characterized by high risks and high costs. If a launch vehicle experiences a catastrophic failure, the cost of the entire launch vehicle, the launch processing, and the payload are completely lost (often in excess of 1,5 billion dollars.) Despite this enormous risk for the payload customer, and indeed the launch provider, launch success rates around the world are not much above 90 percent. The current USAF medium and heavylift launch systems are often based on technology that is 20 years old and older. Furthermore, little historical …


Parallel Implementation Of An Artificial Neural Network Integrated Feature And Architecture Selection Algorithm, Craig W. Rizzo Mar 1998

Parallel Implementation Of An Artificial Neural Network Integrated Feature And Architecture Selection Algorithm, Craig W. Rizzo

Theses and Dissertations

The selection of salient features and an appropriate hidden layer architecture contributes significantly to the performance of a neural network. A number of metrics and methodologies exist for estimating these parameters. This research builds on recent efforts to integrate feature and architecture selection for the multilayer perceptron. In the first stage of work a current algorithm is developed in a parallel environment, significantly improving its efficiency and utility. In the second stage, improvements to the algorithm are proposed. With regards to feature selection, a common random number (CRN) addition is proposed. Two new methods of architecture selection are examined, to …


The Application Of Statistical Sampling Techniques To The Operational Readiness Inspection, Troy L. Dixon, Timothy S. Madgett Mar 1998

The Application Of Statistical Sampling Techniques To The Operational Readiness Inspection, Troy L. Dixon, Timothy S. Madgett

Theses and Dissertations

A Blue Ribbon Commission report to the Air Force Chief of Staff in February 1997 makes several specific recommendations on the conduct of Operational Readiness Inspections. This thesis develops a solution to one of the recommendations of that report; utilize scientifically based sampling techniques to reduce the footprint of the inspection on an evaluated unit. Acceptance sampling, common in industry, is developed for use in the environment of the Operational Readiness Inspection. The time saved from this more efficient sampling practice reduces Inspector General time at an evaluation, decreases the footprint, and answers the specific recommendations of the Blue Ribbon …


Using Simulation To Model Time Utilization Of Army Recruiters, James D. Cordeiro Jr., Mark A. Friend Mar 1998

Using Simulation To Model Time Utilization Of Army Recruiters, James D. Cordeiro Jr., Mark A. Friend

Theses and Dissertations

It is a well-known fact Army recruiters work very long hours in a demanding environment. In many cases, recruiting stations are geographically isolated from military bases, with recruiters often tolerating a high cost of living, crime, and other such adverse conditions that characterize the communities they work in. The job itself demands self-starting, motivated individuals with a wide range of skills, from street-savvy to salesmanship, in order to succeed. A number of factors in recent years have made military recruiting more difficult, which include scandals involving highly-placed soldiers and changes in attitudes towards military service among eligible men and women. …


Application Of Decision Analysis To Evaluate Alternative Research And Development Investments., Michael J. Artelli Mar 1998

Application Of Decision Analysis To Evaluate Alternative Research And Development Investments., Michael J. Artelli

Theses and Dissertations

This thesis is an application of decision analysis techniques to the problem of evaluating competing research and development investments and selecting the best portfolio from among the alternatives. In contrast to the current ad hoc approach, decision analysis provides an explicit and easily explained rationale for investment choices, complete and consistent incorporation of multiple objectives, and direct insight into the effects of uncertain investment returns. A hierarchical objective decomposition was used to capture the user's preference structure. The hierarchy was then used to develop a computer-based decision aid to allow the users to quickly and consistently evaluate technology investment options. …


A Game-Theoretic Improvement Model For Stochastic Networks: Reliability Vs. Throughput, Jeffrey A. Schavland Mar 1998

A Game-Theoretic Improvement Model For Stochastic Networks: Reliability Vs. Throughput, Jeffrey A. Schavland

Theses and Dissertations

Prescriptive models used to allocate resources for network improvement traditionally have used reliability or flow as Measures of Effectiveness (MOEs). Such metrics do not give value to efforts which make a component more difficult to exploit. This study developed an entirely new MOE for stochastic network improvement, flow damage utility, which uses a two person, zero-sum, non-cooperative game to optimize a probabilistic network for an estimate of expected flow minus performance degradation after a worst case component loss. A multiple criteria optimization problem that uses flow damage utility and an analogous, previously developed metric for the reliability problem is used …


Anderson-Darling And Cramer-Von Mises Based Goodness-Of-Fit Tests For The Weibull Distribution With Known Shape Using Normalized Spacings, Eric W. Frisco Mar 1998

Anderson-Darling And Cramer-Von Mises Based Goodness-Of-Fit Tests For The Weibull Distribution With Known Shape Using Normalized Spacings, Eric W. Frisco

Theses and Dissertations

Two new goodness-of-fit tests are developed for the three-parameter Weibull distribution with known shape parameter. These procedures eliminate the need for estimating the unknown location and scale parameters prior to initiating the tests and are easily adapted for censored data. This is accomplished by employing the Anderson-Darling and Cramer-von Mises statistics based on the normalized spacings of the sample data. Critical values of the new tests are obtained for common significance levels by large Monte Carlo simulations for shapes 0.5(0.5)4.0 and sample sizes 5(5)40 with up to 40% censoring (Type II) from the left and/or right. An extensive Monte Carlo …


The Application Of Sequential Convex Programming To Large-Scale Structural Optimization Problems, Todd A. Sriver Mar 1998

The Application Of Sequential Convex Programming To Large-Scale Structural Optimization Problems, Todd A. Sriver

Theses and Dissertations

Structural design problems are often modeled using finite element methods. Such models are often characterized by constraint functions that are not explicitly defined in terms of the design variables. These functions are typically evaluated through numerical finite element analysis (FEA). Optimizing large-scale structural design models requires computationally expensive FEAs to obtain function and gradient values. An optimization approach which uses the SCP sequential convex programming algorithm of Zillober, integrated as the optimizer in the Automated Structural Optimization System (ASTROS), is tested. The traditional approach forms an explicitly defined approximate subproblem at each design iteration that is solved using the method …


Parameter Estimation Of The Mixed Generalized Gamma Distribution Using Maximum Likelihood Estimation And Minimum Distance Estimation, Dean G. Boerrigter Mar 1998

Parameter Estimation Of The Mixed Generalized Gamma Distribution Using Maximum Likelihood Estimation And Minimum Distance Estimation, Dean G. Boerrigter

Theses and Dissertations

The Generalized Gamma is an extremely flexible distribution that is useful for reliability modeling. Among its many special cases are the Weibull and Exponential distributions. A mixture of Generalized Gamma Distributions is even more useful because multiple causes of failure can he simultaneously modeled. This research studied parameter estimation of the special cases of the Mixed Generalized Gamma Distribution and built upon them until the full nine-parameter distribution was being estimated. First, special cases of a single Generalized Gamma Distribution were estimated. Next, mixtures of Exponential distributions with both known and unknown location parameters were estimated. Next, mixtures of Weibull …


A New Sequential Goodness Of Fit Test For The Three-Parameter Weibull Distribution With Known Shape Based On Skewness And Kurtosis, Jonathan C. Clough Mar 1998

A New Sequential Goodness Of Fit Test For The Three-Parameter Weibull Distribution With Known Shape Based On Skewness And Kurtosis, Jonathan C. Clough

Theses and Dissertations

The Weibull distribution finds wide applicability across a broad spectrum of disciplines and is very prevalent in reliability theory. Consequently, numerous statistical tests have been developed to determine whether sample data can be adequately modeled with this distribution. Unfortunately, the majority of these goodness-of-fit tests involve a substantial degree of computational complexity. The study presented here develops and evaluates a new sequential goodness-of-fit test for the three-parameter Weibull distribution with a known shape that delivers power comparable to popular procedures while dramatically reducing computational requirements. The new procedure consists of two distinct tests, using only the sample skewness and sample …


A Life Cycle Cost Model For Innovative Remediation Technologies, Osman S. Dereli Mar 1998

A Life Cycle Cost Model For Innovative Remediation Technologies, Osman S. Dereli

Theses and Dissertations

LCC analysis is a powerful tool for investigating the costs of competing systems. This thesis investigates the cost scaling methods to improve the traditional LCC modeling techniques. The motivation for this research is finding a good estimate for the remediation technologies when the contaminant volume is not exactly known. This specific case lead researcher to investigating the methods of cost scaling and effects of inflation in the cost estimation. As a result of study a generic LCC model is developed. Methods for considering inflation and scaling are recommended and embodied into the model. The developed model is applied the specific …


Using Bayesian Statistics In Operational Testing, Thuan H. Tran Mar 1998

Using Bayesian Statistics In Operational Testing, Thuan H. Tran

Theses and Dissertations

This research explored the applicability of Bayesian methods to the problem of determining the reliability of a series system, a parallel system, and a bridge system. The time to failure of each component in each system is assumed to be exponentially distributed. A basic exponential case and a basic binomial case are also evaluated. In general, using simulated data and real data when possible, the Bayesian methods produced confidence intervals that were much tighter than the classical inference methods, thus allowing a decision maker to have higher confidence in making a decision. System level data and aggregated component level data …


Cross-Resolution Combat Model Calibration Using Bootstrap Sampling, Bryan S. Livergood Mar 1998

Cross-Resolution Combat Model Calibration Using Bootstrap Sampling, Bryan S. Livergood

Theses and Dissertations

The US Air Force uses many combat simulation models to assist them in performing combat analyses. BRAWLER is a high-resolution air-to-air combat simulation model used for engagement-level analyses of few-on-few air combat. THUNDER is a low-resolution combat simulation model used for campaign-level analyses of theater-level warfare. BRAWLER is frequently used to ensure that THUNDER air-to-air inputs are valid. This thesis describes the confederation of THUNDER and BRAWLER by clearly showing how one particular BRAWLER output, the effectiveness of a missile type, is transformed into THUNDER air-to-air input data. Since BRAWLER is a stochastic simulation model, it is necessary to replicate …


A Value Focused Thinking Approach To Academic Course Scheduling, Shane A. Knighton Mar 1998

A Value Focused Thinking Approach To Academic Course Scheduling, Shane A. Knighton

Theses and Dissertations

In 1997, the School of Engineering of the United States Air Force Institute of Technology began exploring ways of automating the academic course scheduling process. The administration desired an expedient approach for course scheduling which supports the institute's mission of "providing scientific and technological education" to officers from all branches of military service, as well as international military forces. The scheduling approach needed to be flexible, efficient, and represent the institute's values and principles. Decision Analysis (DA) and specifically, Value Focused Thinking (VFT), is used to decompose the complex problem of academic course scheduling and determine the factors that are …


An Advanced Visualization Method For An Operations Research Analysis, Steven C. Oimoen Mar 1998

An Advanced Visualization Method For An Operations Research Analysis, Steven C. Oimoen

Theses and Dissertations

Visualizing multidimensional data using only two dimensions and conventional visualization techniques limits the understanding of the data set. Underlying structures or patterns within the data can easily go unnoticed. In order to gain additional insight into an analysis, incorporation of visualization and multidimensional graphics into the analysis results should be accomplished. The results must ensure that the information portrayed is not misleading or misunderstood. The integrity of the data must be preserved throughout the transformation. The primary objective of this research effort is to identify techniques to visualize multidimensional data and then develop a software tool to display the multidimensional …


Verification And Validation Of Faarr Model And Data Envelopment Analysis Models For United States Army Recruiting, Gene M. Piskator Mar 1998

Verification And Validation Of Faarr Model And Data Envelopment Analysis Models For United States Army Recruiting, Gene M. Piskator

Theses and Dissertations

This research has two objectives-to verify and validate the U.S. Army's Forecast and Allocation of Army Recruiting Resources (FAARR) model and to develop a Data Envelopment Analysis (DEA) modeling strategy. First, the FAARR model was verified using a simulation of a known production function and validated using sensitivity analysis and ex-post forecasts. FAARR model forecasts were not accurate and were extremely sensitive to any changes in the model's linear programming constraints and to changes in recruiting resource levels. Second, this research describes a three phase modeling strategy to build accurate DEA models. DEA has become a popular tool to evaluate …


Embedding A Reactive Tabu Search Heuristic In Unmanned Aerial Vehicle Simulations, Joel L. Ryan Mar 1998

Embedding A Reactive Tabu Search Heuristic In Unmanned Aerial Vehicle Simulations, Joel L. Ryan

Theses and Dissertations

We apply a Reactive Tabu Search (RTS) heuristic within a discrete event simulation to solve routing problems for Unmanned Aerial Vehicles (UAVs). Our formulation represents this problem as a multiple Traveling Salesman Problem with time windows (mTSPTW), with the objective of attaining a specified level of target coverage using a minimum number of vehicles. Incorporating weather and probability of UAV survival at each target as random inputs, the RTS heuristic in the simulation searches for the best solution in each realization of the problem scenario in order to identify those routes that are robust to variations in weather, threat, or …


Analysis Of Alternatives: Multivariate Considerations, John J. Siegner Mar 1998

Analysis Of Alternatives: Multivariate Considerations, John J. Siegner

Theses and Dissertations

The Aeronautical System Center (ASC) is developing a Simulation and Analysis Facility (SIMAF) that will link models, simulations, hardware-in-the-loop, and system-in-the-loop resources to create a robust virtual environment supporting assessment of alternate systems in the defense acquisition process. ENS is assisting ASC with scenario development, experimental design, and battleroom visualization efforts for a SIMAF capability demonstration. This thesis uses multivariate analysis and visualization tools to develop an approach for reducing the dimensionality of multiple campaign level measures of effectiveness for a notional Analysis of Alternatives (AoA) study. Additionally, the thesis advances an AoA visualization paradigm for the SIMAF capability demonstration. …


The Measurement Of Human Intellectual Capital In The United States Air Force, Thomas J. Wagner Mar 1998

The Measurement Of Human Intellectual Capital In The United States Air Force, Thomas J. Wagner

Theses and Dissertations

For centuries, companies used basically the same accounting system developed in the fifteenth century to measure economic performance. Through much of this period the tangible value of a firm, its plants, property and equipment, was closely related to the market value of the firm. With the dawning of the information age, America has evolved from a manufacturing based economy to a service oriented economy. Closely related to this change from a blue collar to white collar workplace has been the widening gap between the market value of a company and its tangible assets. Roughly equal before, now the tangible assets …


An Analytical Tool To Assess Aeromedical Evacuation Systems For The Department Of Defense, Scott A. Wilhelm Mar 1998

An Analytical Tool To Assess Aeromedical Evacuation Systems For The Department Of Defense, Scott A. Wilhelm

Theses and Dissertations

The research was commissioned by, and conducted for, the HQ AMC Surgeon General to assist him in making a hard decision. Should the McDonnell-Douglas C-9A Nightingale be replaced, and, if so, with what? Using tools based in Keeney's Value-Focused Thinking methodology, the SG's values for this decision were quantified, alternatives that addressed these values were generated, and those alternatives were evaluated using his values to suggest preferred alternatives.


A Network Disruption Modeling Tool, James A. Leinart Mar 1998

A Network Disruption Modeling Tool, James A. Leinart

Theses and Dissertations

Given that network disruption has been identified as a military objective and C2-attack has been identified as the mechanism to accomplish this objective, a target set must be acquired and priorities assigned to each target set. In order to move beyond subjective target prioritization, development and implementation of a methodology and model, that quantitatively measures the value of each target in achieving the objective, is needed in prioritizing targets. This thesis effort uses a vertex cut-set algorithm on a transformation of the graph representing a notional network of interest. The cut-sets generated represent potential target sets. Value-focused thinking and decision …


An Operational Review Of Air Campaign Planning Automation, William R. Haas Mar 1998

An Operational Review Of Air Campaign Planning Automation, William R. Haas

Theses and Dissertations

The air campaign planning process is a complex and dynamic process. Operations research has been applied to this problem to shorten the planning cycle with mixed results. The Joint Force Air Component Commander Planning Tool was developed as an air campaign planning aid. It uses the Conventional Targeting and Effectiveness Model (CTEM) as the force analysis model for master air attack plan (MAAP) planning. This thesis reviews the limitations and assumptions of CTEM and CTEM in JPT from and operational perspective. A new approach to using models in air campaign planning, collaborative planning, is being developed for use with JPT. …


Investigating Sorbent Geometry Response Surfaces From Sorption Rate Data, H. Michael Harrison Mar 1998

Investigating Sorbent Geometry Response Surfaces From Sorption Rate Data, H. Michael Harrison

Theses and Dissertations

Sorption and desorption of hydrophobic organic compounds (HOCs) into soil particles occurs at Air Force contamination sites. Long-term desorption extends clean up time, costing billions. Accurately modeling desorption will reduce costs and improve clean up designs. State of the art models depict soil as uniform spherical particles which lose the effect of longer sorption path lengths. An alternate approach, the multiple sites in series (MSS) model, describes the sorption capacity of a mixture of soil particle sizes and shapes using a composite particle defined by a two parameter statistical distribution. When the MSS model uses a general radial geometry function …


Generating Bomber Routes For The Delivery Of Gravity Weapons, Gregory J. Ehlers Mar 1998

Generating Bomber Routes For The Delivery Of Gravity Weapons, Gregory J. Ehlers

Theses and Dissertations

United States Strategic Command (USSTRATCOM) is updating the Arsenal Exchange Model (AEM) that it uses for allocating strategic weapons to targets. AEM does not model the range constraints on bomber routes. These routes are used to deliver gravity munitions. In order to include these constraints in the new method, the Weapons Allocation Model (WAM), a pool of routes that satisfy the range constraints needs to be created. The number of possible routes to consider is extremely large and it is not possible to enumerate them all. Therefore, the method to form the pool of routes needs to reduce the number …