Operational Research Commons^™

Synthetic Battlebridge: Information Visualization And User Interface Design Applications In A Large Virtual Reality Environment, Kirk G. Wilson

Theses and Dissertations

With shrinking budgets and fewer personnel, future military training will rely heavily on simulated environments. The goal for this training is to reduce cost while maintaining readiness and unparalleled capability for all levels of military command. This thesis effort, the Synthetic Battle Bridge SBB , provides a real-time simulated environment for military commanders to observe on-going computer simulations of varying participation levels and helps them wring the most from a simulation. The SBB, designed for higher ranking personnel with little time to spend learning how to run the system, must exhibit three capabilities ease-of-use, long-term retention, and adaptability. Based on …

Integration And Enhancement Of The Saber Wargame, Karl S. Mathias

Theses and Dissertations

The Saber wargame is a theater-level air/land battle wargame written in Ada that is being developed for the Air Force Wargaming Center at Maxwell AFB, AL. This thesis documents how the user interface and simulation engine were integrated. Integration was accomplished by developing a portable object-oriented database system (OODBMS) interface. The interface was implemented in Ada and tied to an OODBMS also written in Ada. Using the interface, both subsystems were able to work from a consistent database and exchange information. The user interface was enhanced by converting it from the Software Technology for Adaptable Reliable Systems Ada/X Window System …

A Robust Aggregation Approach To Simplification Of Manufacturing Flow Line Models, Paul Savory

Department of Industrial and Management Systems Engineering: Faculty Publications

One of the more difficult tasks facing a modeler in developing a simulation model of a discrete part manufacturing system is deciding at what level of abstraction to represent the resources of the system. For example, questions about plant capacity can be modeled with a simple model, whereas questions regarding the efficiency of different part scheduling rules can only be answered with a more detailed model. In developing a simulation model, most of the actual features of the system under study must be ignored and an abstraction must be developed. If done correctly, this idealization provides a useful approximation of …

A Robust Aggregation Approach To Simplification Of Manufacturing Flow Line Models, Paul Savory

Department of Industrial and Management Systems Engineering: Presentations

One of the more difficult tasks facing a modeler in developing a simulation model of a discrete part manufacturing system is deciding at what level of abstraction to represent the resources of the system. For example, questions about plant capacity can be modeled with a simple model, whereas questions regarding the efficiency of different part scheduling rules can only be answered with a more detailed model. In developing a simulation model, most of the actual features of the system under study must be ignored and an abstraction must be developed. If done correctly, this idealization provides a useful approximation of …

The Application Of Simulated Annealing To Stochastic Systems, Charles B. Warrender

Theses and Dissertations

Simulated Annealing was used to optimize three constrained simulation models. For each of these models, seven different acceptance functions were evaluated and compared against the performance of Local Search. These comparisons demonstrated the affect that different acceptance functions have on the performance of the algorithm. The performance was measured by the average solution quality and average efficiency obtained from several runs. The first model facilitated the implementation of Simulated Annealing using the SLAM simulation language. The configuration space was small, described by only two decision variables. It demonstrated the viability of using Simulated Annealing to optimize the variable settings in …

A Parametric Regression Of The Cost Of Base Realignment Action (Cobra) Model, Douglas D. Hardman, Michael S. Nelson

Theses and Dissertations

This study develops a parametric model that is capable of generating accurate estimates of the costs to close Air Force installations. The new model is based upon, but much simpler to use than, the Cost of Base Realignment Action (COBRA) model. COBRA is an economic cost analysis model that requires a minimum of 250 inputs and as many as 700 inputs. The new parametric model requires just 10 input variables and was developed using least squares multiple regression. Comparison of the new parametric model to COBRA indicates that it captures 91 percent of the variance in cost estimates generated by …

An Investigation Of Alternative Metamodels For The Theater Simulation Of Airbase Resources Model, Alistair G. Dally

Theses and Dissertations

This study is an exploratory investigation into the development of metamodels of a particular Theater Simulation of Airbase Resources (TSAR) simulation model. Techniques applicable to the development of metamodels from a simulation using an orthogonal two-level fractional factorial experimental design are discussed. The experimental design is found to limit the metamodel form to polynomial linear least squares regression models, and also to greatly simplify the process of building regression models. Using the simulation results from previous research, alternate metamodels are proposed for both the prediction of sorties generated by the airbase system, as modeled by the simulation; and to assist …

A Computer-Based Strategy To Facilitate Organizational Learning Process, Charles B. Keating

Engineering Management & Systems Engineering Theses & Dissertations

This research investigated the development of Organizational Learning Process (OLP) through the application of a computer-based strategy in an organizational setting. OLP is developed from the organizational learning literature as an integration of similar concepts of organizational processes of inquiry essential to organizational learning. These concepts included: organizational dialectic (Argyris and Schon 1978), surfacing and testing mental models (Senge 1990a,1990b), and interpretation process (Daft and Weick 1984). A qualitative research methodology was developed within a participatory action research framework (Whyte 1989). A six phase research project, designed as a computer-based strategy to generate OLP, was applied in an organizational setting. …

Development Of A Knowledge Based System For Wastewater Pipeline Failure Risk Assessment, Adam Mayanzani Ngaliga

Engineering Management & Systems Engineering Theses & Dissertations

The purpose of this thesis was to study and analyze the wastewater pipeline failure risk assessment process, and then design and develop an effective and efficient wastewater pipeline risk assessment tool for the Hampton Roads Sanitation District, in Virginia, U.S.A. A knowledge based system was developed using an expert system building shell (Xi-Plus).

The system design is based on the knowledge elicited from the experts and literature in sanitary pipeline failure risk evaluation. The knowledge base contains both heuristics and procedural rules. The system interprets the information provided by the user and reasons from that information to reach conclusions on …

Cross-Cultural Issues In The Management Of German-Owned Business Subsidiaries In Hampton Roads, Teja Ulrich

Engineering Management & Systems Engineering Theses & Dissertations

'Culture' can be described as patterns of thinking, feeling and acting that distinguish one cultural group from another. Cultural diversity is therefore likely to introduce variety to organizations in which individuals from different national backgrounds are working together. Although this variety bears the potential for an improvement of the cognitive development in the organizations, managers of multicultural business organizations tend to perceive cultural diversity as a disadvantage. This thesis attempts to identify the impact of cultural differences between Germans and Americans on organizations in which German managers work with American employees. German managers of eight business subsidiaries in the Hampton …

A Sociotechnical Approach To The Study Of Semiautonomous Work Group Communication In Technical Organizations, Elizabeth B. Varnes

Engineering Management & Systems Engineering Theses & Dissertations

The sociotechnical aspects of group communication in semiautonomous technical work teams were investigated to understand how team members define "effective" group communication and what impact technical tools have on the group communication process. A team of workers with various technical backgrounds was selected for study. The study involved videotaped group sessions, a group training educational briefing and individual group member questionnaires. The results indicate that group members believed sharing information among group members was critical to successful communication and that certain technical tools could be effective during group meetings. The findings are congruent with the general theory that group communication …

Integrating Psychological Operations Into The Joint Theater Level Simulation (Jtls), C. Matthew Pecot Iii

Theses and Dissertations

This thesis provides a prototype and methodology for integrating psychological operations (PSYOP) into the Joint Theater Level Simulation (JTLS) combat model. The requirement rose out of the need for aggregate-level training models to reflect the role of PSYOP so that commanders and their staffs can learn how to manage plan for, and conduct PSYOP within the context of AirLand battle doctrine. As the JTLS model currently exists, there is no representation of psychological operations whatsoever. This thesis outlines a methodology for incorporating the PSYOP analysis process (including the target audience analysis), the PSYOP product development and production process, the PSYOP …

Using Animation In The Validation Of Simulation Models, Michael L. Carpenter

Theses and Dissertations

This study examined three aspects of animation (movement, color, and detail of icons) to determine which one (or ones) best communicated the operation of a simulation model. The procedure was done in the context of using animation to establish a model's face validity. Movement, color, and detail of icons were looked at individually and in combination. The ability to communicate was measured both subjectively and objectively. The subjective measures were a selection of best and worst animation types where best and worst referred to how well an animation communicated, and a pairwise comparison of the animation types which resulted in …

A Monte Carlo Study Of The Raw And Normal Varimax Rotation Criterion In Factor Analysis, Willam M. Ibinson

Theses and Dissertations

Factor analysis is a multivariate statistical procedure for analyzing and reducing large data sets. Many factor analysis schemes and techniques are available that lead to strikingly different results from the same data. This research effort used a Monte Carlo approach to investigate the properties of two rotation methods for simple structure, Kaiser's raw and normal varimax criterion. Data sets were developed from a set of contrived experimental factor patterns by multiplying each factor pattern by its transpose to create a covariance matrix. Data sets of multivariate normal deviates were in turn generated from each covariance matrix via the Choleski algorithm. …

Theater Airlifter Survivability On The Ground, Michael A. Silver

Theses and Dissertations

Airlifter attrition can severely decrease the throughput of cargo during extended airlift operations. Much work has been done to enhance the tactical airlifter survivability in the air but little study has gone into airlifter survivability on the ground. This thesis develops a method to measure the threat to parked aircraft from ground weapons. Specific scenarios cover airlifter mobility on the ground, time to off-load cargo, short-field takeoff capability and attack by infantry weapons. A weapon is examined at each of several firing ranges to target. The threat to the aircraft is measured as the probability that the aircraft is hit. …

A Modified Chi-Squared Goodness-Of-Fit Test For The Three-Parameter Gamma Distribution With Unknown Parameters, Thomas J. Sterle

Theses and Dissertations

A modified chi-squared goodness-of-fit test was created for the gamma distribution in the case where all three parameters must be estimated from the sample. Critical values are generated using a Monte Carlo simulation procedure with 5000 repetitions each. Random samples of 8 different sizes were drawn from gamma distributions with shape parameters 1, 1.5, 2., and 2.5. The shape, scale, and location parameters were then estimated from each sample, using an iterative technique combining the maximum likelihood and minimum distance methods, enabling, computation of the chi-squared statistics and critical values. The same process is used to generate random samples, parameter …

The Use Of Simulation To Evaluate Strategic Aeromedical Evacuation Policy And Planning, Charles W. Wolfe Jr.

Theses and Dissertations

Strategic aeromedical evacuation (AE) of casualties from the theater of operations to the CONUS during wartime is a complex operation that involves the integration of medical personnel and policies with airlift concepts and capabilities. Military analysts within the Air Mobility Command Analysis Group (AMC/XPY) have traditionally used deterministic linear programming techniques to estimate the number of aircraft the United States Air Force (USAF) requires for given contingency scenarios. However, this group has yet to develop a stochastic approach to validate their resource recommendations, and more importantly, to study the interrelationships between key factors comprising strategic aeromedical evacuation. As the possibility …

A New Goodness-Of-Fit Test For The Weibull Distribution Based On Spacings, Mark C. Coppa

Theses and Dissertations

The critical values for a new goodness-of-fit test based on spacings are generated for the Weibull distribution when the shape parameter is known. The critical values are used for testing whether a set of observations follow a Weibull distribution when the scale and location parameters are unknown. A Monte Carlo simulation with 10,000 iterations is used to generate the critical values for sample sizes 5(5)35 at shape parameters k equal to 0.5(0.5)1.5 and for sample sizes 5(5)20 at shape parameters k = 2.0(1.0)4.0. A Monte Carlo power study of the Z* test statistic using 5000 iterations is accomplished using nine …

Patient Scheduling And Aircraft Routing For Strategic Aeromedical Evacuation, Michael J. Loftus

Theses and Dissertations

The objective of this study is to develop an approach that would assign patients to aeromedical evacuation aircraft and route each aircraft to a single CONUS airport. The goal is to minimize total patient wait time. A heuristic algorithm is developed which exploits the structure of the problem. The first subproblem solved is the assignment of aircraft to airports. This subproblem is solved using integer programming and the results are input into the second subproblem. The second subproblem is the patient to aircraft assignment problem. This subproblem minimizes patient wait time and is solved using network flow programming. The two …

An Empirical Evaluation Of Five Circular Error Probable Estimation Techniques And A Method For Improving Them, William L. Tongue

Theses and Dissertations

This study compared five CEP estimation techniques under the assumption that the crossrange and downrange miss distances of the sample data follow a bivariate normal distribution. The analysis determined the sensitivities of these models to changes in sample size, bias, correlation, and ellipticity in terms of three measures of effectiveness: Mean relative error (RE), variance of RE, and mean squared error (MSE) of RE. In general, it was found that sample size was the most significant parameter in determining the best CEP method. Mean RE provided a 'strong' distinction between estimators, while variance and MSE provided 'weak' distinctions between estimators. …

Cost Constrained Improvements To The Military Retirement System, Cynthia A. Brown

Theses and Dissertations

This research studies possible changes to the current military retirement system. The current military retirement system refers to the system provided under the Military Reform Act of 1986, A new system is proposed which would provide the retiree with four options. Option 1 would provide a pay annuity and medical benefits to the retiree (this is the current system). Option 2 would provide a pay lump sum in place of the, annuity and would offer medical benefits. Option 3 would offer the pay annuity but give a medical lump sum amount in place of the medical benefit. Finally, option 4 …

Enhancements To The Animated Tutor For Air Combat Simulation, David A. Legge

Theses and Dissertations

This study investigates the use of the Ada programming language in combat modeling. It takes an existing combat model, the Animated Tutor for Air Combat Simulation (ATACS), and re-writes it into Ada. The new model also includes enhancements to the original model. ATACS+, as it is now called, is used as a learning tool in combat modeling classes at the Air Force Institute of Technology. ATACS+ consists of a preprocessor and a model, complete with two and three-dimensional graphics and engagement status reports. Conclusion are made about Ada's suitability for combat modeling, some of the features of Ada which can …

Predicting The Productive Capacity Of Air Force Aerospace Ground Equipment Personnel Using Aptitude And Experience Measures, Robert S. Faneuff

Theses and Dissertations

This study investigated the effects of mechanical aptitude and job experience on the job performance of 204 Air Force Aerospace Group Equipment (AGE) mechanics. Job performance was expressed as productive capacity (PC), which is derived from estimated performance times on job tasks. PC measures were derived for 50 tasks typically performed by airmen in the specialty. Aptitude measures took the form of Mechanical percentile composite scores on the Armed Services Vocational Aptitude Battery (ASVAB). A second-order logistic model was used to regress PC on aptitude and experience at the task level and at the overall job, or aggregate, level. Model …

Bradley Fighting Vehicle Gunnery: An Analysis Of Engagement Strategies For The M242 25-Mm Automatic Gun, James G. Riley

Theses and Dissertations

This thesis studies various engagement strategies for the Bradley Fighting Vehicle's 25-mm automatic gun firing APDS-T ammunition against a BMP- type target. The Army currently provides only the broadest guidance for the structure of the 25-mm point target engagement which results in the employment of an assortment of strategies throughout the Bradley community. The goal of this research was to determine if a best method exists. Bradley gunnery is a complex set commander/gunner interactions which can be difficult to represent with the analytic models commonly found in the literature. A model, based on the simulation methods used by the US …

An Analysis Of The Generalized Lambda Distribution, Robert J. Bergevin

Theses and Dissertations

The Generalized Lambda Distribution (GLD) is a four parameter function that is capable of mimicking the behavior of a wide range of probability density functions (pdfs). Unfortunately, the GLD presently cannot model every possible type of pdf. Since the reasons for this limitation are unknown, this thesis examines several potential problems in an attempt to expand the range of distributions the GLD can mimic. We first present a discussion of the behavior of the algorithm that is used to search for the appropriate GLD parameter values. In particular, we examine the effect of using an unconstrained search to find the …

An Analysis Of Tactical Airlifter Characteristics And Their Impact On Theater Airlift System Performance, John J. Koger

Theses and Dissertations

This study used computer simulation and Response Surface Technology to determine what tactical airlifter characteristics most impact theater airlift system performance in a Southwest Asia (SWA) scenario. Some Aircraft characteristics were grouped into functional sets, while others were considered individually. After screening one characteristic, reliability, with a two-level factorial experiment, a Box-Behnken design was used to estimate second-order metamodels. A stepwise regression procedure indicated that, if attrition rates are ignored, airlift system performance is most impacted by the aircraft's size, survivability, cruise speed, and ability to operate on short fields. The SWA scenario used in this study covers a large …

Automating The Satellite Range Scheduling Process, Timothy D. Gooley

Theses and Dissertations

Satellite range scheduling is a complex problem that involves scheduling satellite supports in which a satellite and a specific remote tracking station are assigned a time window during which they communicate with each other. As the number and complexity of satellite supports continue to increase, more pressure is placed on the current manual system to efficiently generate a schedule. The objective of this research was to develop a methodology that will automate the generation of the initial 24 hour schedule. The goal of the algorithm developed was to schedule as many conflict free supports as possible. A two phased approach …

The Airlift Capabilities Estimation Prototype: A Case Study In Model Validation, Randy Mccanne

Theses and Dissertations

This study investigates the application of a life cycle approach to the validation of operational models. The classic waterfall life cycle from software engineering is adapted for use on mathematical models by defining four stages of model development. Each stage is discussed in detail and examples of the output from each stage are presented. In addition, techniques are investigated for applying the proposed life cycle to existing models through the recovery of life cycle stages. The methodology is applied to a linear programming model developed for planning airlift operations to demonstrate the power of the life cycle approach to validation. …

A Modified Anderson Darling Goodness-Of-Fit Test For The Gamma Distribution With Unknown Scale And Location Parameters, Tamer Ozmen

Theses and Dissertations

A new modified Anderson-Darling goodness-of-fit test is introduced for the three-parameter Gamma distribution when the location parameter is found by minimum distance estimation and scale parameter by maximum likelihood estimation. Monte Carlo simulation studies were performed to calculate the critical values for A-D test when A-D statistic is minimized. These critical values are then used for testing whether a set of observations follows a Gamma distribution when the scale and location parameters axe unspecified and are estimated from the sample. Functional relationship between the critical values of A-D is also examined for each shape parameter by the variables, sample size …

Modified Anderson-Darling And Cramer-Von Mises Goodness-Of-Fit Tests For The Normal Distribution, David A. Gwinn Sr.

Theses and Dissertations

New techniques for calculating goodness-of-fit statistics for normal distributions with parameters estimated from the sample are investigated. Samples are generated for a Normal(0,1) distribution. Critical values are calculated for five modifications to the Anderson-Darling statistic and five modifications to the Cramer-Von Mises statistic. An extensive power study is done to test the power of the new statistics versus the power of the unmodified statistics. Powers of six of the new statistics show minimal to no improvement, two of the new statistics show a marked decrease in power, and two of the new statistics show an overall increase in power over …