Operational Research Commons^™

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 …

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. …

Calculating A Value For Dominant Battlespace Awareness, Eric A. Beene

Theses and Dissertations

In times of ever-tightening military budgets, methodologies are required that can compare the contributions of various systems involved in the warfighting process. While many tools are in use that directly measure the effects of greater numbers of enhanced hardware, and even improved processes, no validated methodology exists to measure elements that contribute to Command, Control, Communications, and Computers (C4); Intelligence, Surveillance, and Reconnaissance (ISR); or to analytically compare these elements with more traditional hardware. This thesis develops a methodology for mathematically quantifying awareness in a military command and control (C2) environment. This methodology begins with the Observe-Orient-Decide-Act Loop to show …

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 …

An Airlift Hub-And-Spoke Location-Routing Model With Time Windows: Case Study Of The Conus-To-Korea Airlift Problem, David W. Cox

Theses and Dissertations

Traditionally, the United States Air Force's Air Mobility Command (AMC) has used the concept of direct delivery to airlift cargo and passengers from a point of embarkation to a point of debarkation. This study develops an alternative hub-and-spoke combined location-routing integer linear programming prototype model, and uses this model to determine what advantages a hub-and-spoke system offers, and in which scenarios it is better-suited than the direct delivery method. Additionally, the analysis suggests that the C-17 may be better-suited, in certain airlift situations, for theater airlift versus strategic (direct delivery) airlift. The model features the following elements: time windows, cargo …

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 …

Solving Geometric Knapsack Problems Using Tabu Search Heuristics, Christopher A. Chocolaad

Theses and Dissertations

An instance of the geometric knapsack problem occurs in air lift loading where a set of cargo must be chosen to pack in a given fleet of aircraft. This paper demonstrates a new heuristic to solve this problem in a reasonable amount of time with a higher quality solution then previously reported in literature. We also report a new tabu search heuristic to solve geometric knapsack problems.

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 …

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 …

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 …

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

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 …

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 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 …

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 …

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 …

A Multithreaded Scheduler For A High-Speed Simulator, Gene Saghi, Kirk Reinholtz, Paul Savory

Department of Industrial and Management Systems Engineering: Faculty Publications

The Cassini spacecraft is on its journey to Saturn to perform a close-up study of the Saturnian system; its rings, moons, magneto-sphere, and the planet itself. Sequences of commands will be sent to the spacecraft by ground personnel to control every aspect of the mission. To validate and verify these command sequences, a bit-level, high-speed simulator (HSS) has been developed. To maximize performance, the HSS is implemented with multiple threads and runs on a multiprocessor system. A key component of the HSS is the scheduler, which controls the execution of the simulator. The general framework of the scheduler can be …

Development Of A Quality Assurance Plan For A Microbrewery, Matthew J. Williams

Theses: Doctorates and Masters

Quality assurance (QA) has become a key factor to business success in the marketplace. Within Australia, companies normally approach QA by implementing formal systems which maintain the consistency of manufacturing processes, and hence, the quality of subsequent output. These systems have increasingly been based upon the international series of standards, ISO 9000.In the food industry, safety is a minimum requirement for food quality. As Governments and food authorities have endeavoured to reduce the incidence of foodborne illnesses, they have promoted the implementation of additional systems developed to a specific standard for food safety, namely Hazard Analysis Critical Control Point (HACCP). …

Scheduling And Sequencing Arrivals To A Stochastic Service System, Peter M. Vanden Bosch

Theses and Dissertations

Optimization of scheduled arrival times to an appointment system is approached from the perspectives of both queueing and scheduling theory. The appointment system is modeled as a one-server, first-come-first-served, transient queue with independent, distinctly distributed service times and no-show rates. If a customer does show, it is assumed to be punctual. The cost of operating the appointment system is a convex combination of customers' waiting times and the server's overtime. While techniques for finding the optimal static and dynamic schedules of arrivals have been proposed by other researchers, they mainly have focused on identical customers and strictly punctual arrivals. This …

A Proposed Approach To Iso Compliance And Validation For Metrology Laboratories, J. Lyle Bagley

Engineering Management & Systems Engineering Theses & Dissertations

International competition among metrology laboratories, as well as their customers, has intensified the incentive to seek either accreditation to ISO Guide 25 or ISO 9000 quality system registration for the laboratory. The debate continues as to which is more beneficial to the laboratory and its customers once the decision is made to pursue one or the other. This study addresses the advantages and limitations of each, and how best to prepare for complying with ISO standards. The literature was reviewed and ISO certification experts were questioned about these issues. The results were combined with new applications of existing operations research …

Focused Graduate Education: An Invisible But Real Competitive Edge, Roland D. Kankey, Jan P. Muczyk, Neal M. Ely

Faculty Publications

The future mission of the Air Force will be diverse and complex. Advanced technology will play an increasingly prominent role; a smaller force must accomplish more. To support this mission, our acquisition corps must be intellectually capable, well educated and trained. Focused graduate education will be essential to sustain this effort.

A Synthesized Methodology For Eliciting Expert Judgment For Addressing Uncertainty In Decision Analysis, Richard W. Monroe

Engineering Management & Systems Engineering Theses & Dissertations

This dissertation describes the development, refinement, and demonstration of an expert judgment elicitation methodology. The methodology has been developed by synthesizing the literature across several social science and scientific fields. The foremost consideration in the methodology development has been to incorporate elements that are based on reasonable expectations for the human capabilities of the user, the expert in this case.

Many methodologies exist for eliciting assessments for uncertain events. These are frequently elicited in probability form. This methodology differs by incorporating a qualitative element as a beginning step for the elicitation process. The qualitative assessment is a more reasonable way …

Sensitivity Analysis Of A Combat Simulation Using Response Surface Methodology, William J. Berg

Theses and Dissertations

This thesis provides a methodology to analyze the sensitivity of a combat simulation relative to the capabilities of the modeled weapon systems. Response Surface Methodology (RSM) was the primary technique used for analysis. A ground battle scenario was developed with a commercial PC wargame Empire II: The Art of War(TM). In the computer verses computer mode, the wargame was transformed into a combat simulation'. A screening experiment was used to determine which of an original 23 weapon factors were actually significant to this scenario. After analyzing the remaining five factors, only three ended up as truly significant to the battle …

Ranking And Generating Alternatives For The National Air Intelligence Center's (Naic) Resource Allocation Strategy, Steven M. Cox

Theses and Dissertations

Allocating resources is never an easy task, especially when requirements call for more resources than those available. It gets more difficult when the availability of resources shrinks from year to year. This is the case at the National Air Intelligence Center (NAIC). In each of the past five years, NAIC has been forced to make their resource allocation decision with fewer dollars and less manpower. This decision has been time consuming, manpower intensive, and sometimes very heated. In an effort to lessen these three consequences, a resource allocation model, based upon the NAIC Commander's values and preferences, was developed. The …

Modeling A Chemical Battlefield And The Resulting Effects In A Theater-Level Combat Model, Todd M. Gesling

Theses and Dissertations

This thesis describes the development of a methodology to model chemical weapons use in the Joint Staff's Joint Warfare Analysis Experimental Prototype (JWAEP) and to quantify the resulting effects. The methodology incorporates organic unit assets and theater-level chemical assets into JWAEP by using the three principles of nuclear, biological, and chemical defense (NBC) which reflect joint and Army doctrine, and combines them with the basic concepts already used in existing theater-level models. Other aspects of the problem include representing chemical 'packages' on the battlefield, determining attrition and time effects, adjusting unit effectiveness, determining chemical package intelligence acquisition procedures, identifying solution …

Linking Procurement Dollars To An Alternative Force Structures' Combat Capability Using Response Surface Methodology, James B. Grier

Theses and Dissertations

A General Officer Steering Group, chaired by HQ USAF/XOM tasked action to develop and implement evaluation and analysis support to lead turn' the Program Objective Memorandum (POM) and Joint Warfare Capability Assessment (JWCA) process. This evaluation process should be designed to supply measures of the 'health' of the Air Force program in light of the Defense Planning Guidance (DPG) and the Chairman's Program Assessment (CPA). The Air Force needs to be able to quickly evaluate various alternative force structures with regards to its combat capability, measured in terms of theater level campaign objectives (CO). HQ USAF/XOM tasked HQ USAF/XPY to …

A Decision Support System For Joint Force Air Component Commander (Jfacc) Combat Planning, Donald W. Hinton

Theses and Dissertations

This system allows assessment of the Master Air Attack Plan (MAAP) during construction and at completion. The system functions around a relational database management system providing a decision support tool for the Guidance, Apportionment, & Targeting (GAT) cell of Central Command's JFACC Combat Plans. A Microsoft Access application is programmed to provide PC-based, real time evaluation of air campaign goals and constraints. The decision support system was validated in February 1997 by the CENTAF combat plans staff at Blue Flag 97-1. The software and user's manual are maintained at HQ ACC/XP-Studies and Analysis Squadron.

Simulation Model Of Fighter Pilot Assignment Process, Anthony J. Hutfles

Theses and Dissertations

This thesis analyzes the effect Continental United States (CONUS) Time on Station (TOS) has on filling critical rated assignments. A SIMSCRIPT II.5 simulation model of the F15 and F16 pilots assignment process was developed. The simulation tested the effect of changing CONUS TOS from 3 years to 6 years in half year increments. Analysis of the number of unfilled rated assignments from simulation runs of 10 years in length indicated that changing CONUS TOS by itself has no statistically significant effect on model's output. The analysis was expanded to a 2(2) factorial experimental design using CONUS TOS and Total Active …

Selecting A Health Care Option For Military Beneficiaries That Minimizes Health Care Costs While Maintaining Personal Desires For Choice, Norman H. Pallister

Theses and Dissertations

Tricare, the triservice, triple-option, managed care plan for the uniformed services, incorporates a managed care support contract to complement Military Treatment Facilities. Currently being implemented throughout the CONUS, Tricare provides more equitable health care service to all military beneficiaries, improved access to care, a reduction in health care costs, and provides beneficiaries with an expanded choice of medical-care providers. This thesis examines the Tricare program and reviews relevant health care literature, both military and civilian. Using these inputs, the author presents a deterministic decision analysis model that allows a military beneficiary to select a health care option that minimizes his …

Analysis Of A Methodology For Linear Programming Optimality Analysis, Chanseok Jeong

Theses and Dissertations

The methodology of Johnson, Baner, Moore, and Grant can be applied to large scale linear programming models. A methodology for optimality analysis of linear programs was developed to create metamodels using response surface methodology techniques such as experimental design and least squares regression. A metamodel consists of a simple equation which is able to predict the optimal objective function value of a linear program. What is needed is some large scale application of the techniques to verify how accurate they are. In the research, I plan to use the large scale LP model, STORM. I use the "Hot Start" idea …