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Articles 481 - 510 of 602
Full-Text Articles in Operational Research
A Methodology For Comparing The Value Of Competing Afmc Manpower Allocation Strategies, Sandra K. Smith
A Methodology For Comparing The Value Of Competing Afmc Manpower Allocation Strategies, Sandra K. Smith
Theses and Dissertations
This research effort develops a methodology for Air Force Materiel Command (AFMC) decision makers to use during mandated resource allocation exercises for comparing competing manpower allocation strategies. A value model is used to represent the hierarchical objectives of the command, with the primary objective being the attainment of maximum mission effectiveness in the face of constrained resources. Value model decomposition is patterned according to the command's organizational structure. Scoring functions derived using direct assessment survey techniques capture the relationship between manpower and mission effectiveness for lowest level organizations. An additive value function represents the model mathematically; the primary objective value …
Dynamic Maintenance Scheduling For A Stochastic Telecommunication Network: Determination Of Performance Factors, Todd S. Patterson
Dynamic Maintenance Scheduling For A Stochastic Telecommunication Network: Determination Of Performance Factors, Todd S. Patterson
Theses and Dissertations
This research proposes an analytical approach to access the relationship between maintenance facility location and communication network performance measurement using a selected dynamic maintenance scheduling protocol. There were three objectives established for this effort. The first objective was the determination of an upper-bound upon the level of performance for a telecommunication network using dynamically scheduled maintenance to evaluate maintenance depot location. This was achieved by using a two-stage algorithm, first locate a maintenance depot by using stochastic algorithms, and then to measure the resulting impact upon performance with a multi-commodity network flow model. The second objective was to develop the …
An Improved Heuristic For Intercontinental Ballistic Missile Crew Scheduling, Michael D. Shirley Jr.
An Improved Heuristic For Intercontinental Ballistic Missile Crew Scheduling, Michael D. Shirley Jr.
Theses and Dissertations
Creating monthly schedules for missile crews is a complex and time-consuming problem. Thousands of events must be scheduled for several hundred missile officers. The rules and regulations governing the problem are numerous, and there are currently no established measures for missile crew schedules. The scheduling software currently available only schedules a fraction of the events. The objectives of this research were to create a rule-based heuristic which could quickly produce feasible or near-feasible schedules, to make the scheduling process paperless, and to develop possible measures of effectiveness for missile crew schedules. The research was successful in each of these areas. …
A Multi-Attribute-Utility-Theory Model That Minimizes Interview-Data Requirements: A Consolidation Of Space Launch Decisions, Raymond W. Staats
A Multi-Attribute-Utility-Theory Model That Minimizes Interview-Data Requirements: A Consolidation Of Space Launch Decisions, Raymond W. Staats
Theses and Dissertations
This research uses multi-attribute utility theory (MAUT) to define a mathematical representation of a decision maker's utility associated with a satellite system. While developing the survey instrument, we focused on making it simpler to administer, primarily by eliminating the use of lottery questions. These simplifications enabled us to shorten our interview with the decision maker to under two hours for a rather complex model.
Analysis Of The Jplan Exercise As An Experimental Learning Tool, Mark J. Lynch, Michael E. Washington
Analysis Of The Jplan Exercise As An Experimental Learning Tool, Mark J. Lynch, Michael E. Washington
Theses and Dissertations
The purpose of this study is to develop an effective educational tool for the Combat Logistics course offered at the Air Force Institute of Technology. The current tool being used, the JPLAN Exercise, was identified as outdated in several areas. The research focused upon four investigative questions what makes an effective educational tool, should the existing exercise be revised or replaced, which logistics principles are essential for incorporation into the educational tool, and is the updated tool significantly different from the original. To answer these questions, we conducted an extensive literature review that focused on two areas. The first area …
Embedded Chaotic Time Series: Applications In Prediction And Spatio-Temporal Classification, James R. Stright
Embedded Chaotic Time Series: Applications In Prediction And Spatio-Temporal Classification, James R. Stright
Theses and Dissertations
The Deterministic Versus Stochastic algorithm developed by Martin Casdagli is modified to produce two new, methodologies, each of which selectively uses embedding space nearest neighbors. Neighbors which are considered prediction relevant are retained for local linear prediction, while those which are considered likely to represent noise are ignored. For many time series, it is shown possible to improve on local linear prediction with both of the new algorithms. Furthermore, the theory of embedology is applied to determine a length of test sequence sufficient for accurate classification of moving objects. Sequentially recorded feature vectors of a moving object form a training …
Dynamic Load Balancing For A Parallel Discrete-Event Battlefield Simulation, Seth R. Guanu
Dynamic Load Balancing For A Parallel Discrete-Event Battlefield Simulation, Seth R. Guanu
Theses and Dissertations
This thesis investigates issues involved in developing a dynamic load balancing model for a parallel discrete event battlefield simulation. The research covers issues in task management, discrete-event simulation, parallel simulation, and load balancing. There are four primary issues discussed concerning the design of a dynamic load balancing model. The first issue is processor load evaluation which deals with the calculation of the amount of work on a processor. The second issue is load balancing profitability determination which deals with the decision to load balance or not based on some cost-gain relationship. The third issue is task migration which deals with …
Application Of Sequential Quadratic Programming To Large-Scale Structural Design Problems, Mark A. Abramson
Application Of Sequential Quadratic Programming To Large-Scale Structural Design Problems, Mark A. Abramson
Theses and Dissertations
Large-scale structural optimization problems are often difficult to solve with reasonable efficiency and accuracy. Such problems are often characterized by constraint functions which are not explicitly defined. Constraint and gradient functions are usually expensive to evaluate. An optimization approach which uses the NLPQL sequential quadratic programming algorithm of Schittkowski, integrated with the Automated Structural Optimization System ASTROS is tested. The traditional solution approach involves the formulation and solution of an explicitly defined approximate problem during each iteration. This approach is replaced by a simpler approach in which the approximate problem is eliminated. In the simpler approach, each finite element analysis …
A Simulation Approach To Granite Sentry System Analysis, Marilyn J. Bauer
A Simulation Approach To Granite Sentry System Analysis, Marilyn J. Bauer
Theses and Dissertations
This study demonstrated the use of simulation modelling to analyze Granite Sentry system performance. The availability simulation model constructed provides a number of system performance measures as a function of component MTBFs and MTTRs. Analysis of failure data prior to model construction supported the generally accepted use of exponentially distributed failure rates and lognormally distributed repair times.
A Mean Value Analysis Heuristic For Analysis Of Aircraft Sortie Generation, Richard C. Jenkins
A Mean Value Analysis Heuristic For Analysis Of Aircraft Sortie Generation, Richard C. Jenkins
Theses and Dissertations
The primary objective of this study was to develop an analytical methodology based on the Mean Value Analysis algorithm that approximates the performance characteristics of a queueing network model QNM containing a fork- join queue with probabilistic branching. These performance characteristics are response time, throughput and queue length at each station. The QNM solved contains the essential features of the aircraft sortie generation process. The sensitivity of the methods accuracy to increases in server utilization was determined. The comparisons of the results of the MVA heuristic to the outputs of the Logistics Composite Model LCOM simulation indicate that the heuristics …
A Fortran Based Learning System Using Multilayer Back-Propagation Neural Network Techniques, Gregory L. Reinhart
A Fortran Based Learning System Using Multilayer Back-Propagation Neural Network Techniques, Gregory L. Reinhart
Theses and Dissertations
An interactive computer system which allows the researcher to build an optimal neural network structure quickly, is developed and validated. This system assumes a single hidden layer perceptron structure and uses the back- propagation training technique. The software enables the researcher to quickly define a neural network structure, train the neural network, interrupt training at any point to analyze the status of the current network, re-start training at the interrupted point if desired, and analyze the final network using two- dimensional graphs, three-dimensional graphs, confusion matrices and saliency metrics. A technique for training, testing, and validating various network structures and …
Assessing The Vulnerability Of Multi-Commodity Networks With Failing Components, Alan R. Robinson
Assessing The Vulnerability Of Multi-Commodity Networks With Failing Components, Alan R. Robinson
Theses and Dissertations
This research proposes an analytical approach for assessing flow disturbance, or compromise, based on limited sampling of arc flow information in multi-commodity, or multiple origin-destination O-D, networks with failing arcs. There were three objectives established for this research. The first objective was to bound the expected flow, given the arcs fail with certain probabilities, which was accomplished by reviewing current approaches for single-commodity networks and extending the results to the multi-commodity case. The second objective was to determine the best placement of flow monitors to obtain the most accurate estimates of O-D pair volumes. This was accomplished using a multi-criteria …
The Effective Use Of Animation In Simulation Model Validation, Christopher L. Swider
The Effective Use Of Animation In Simulation Model Validation, Christopher L. Swider
Theses and Dissertations
This study examined two animation displays moving icons, bar graphs at two presentation speeds to determine how each of these factors affected the animations ability to communicate violations of model assumptions. Subjects viewed animation displays individually and in combination at each presentation speed. Eight problem scenarios were presented to evaluate each animations ability to communicate violations of different assumptions. Each animations communication ability was measured subjectively and objectively. Subjective measures in the form of pairwise comparisons were used to calculate normalized preference ratings for each animation. objective measures included problem identification accuracy and problem time. Subjective results indicated that moving …
An Rsm Study Of The Effects Of Simulation Work And Metamodel Specification On The Statistical Quality Of Metamodel Estimates, Michael K. Taylor
An Rsm Study Of The Effects Of Simulation Work And Metamodel Specification On The Statistical Quality Of Metamodel Estimates, Michael K. Taylor
Theses and Dissertations
This research investigated the combined influence of simulation work and metamodel specification on the statistical quality of the estimates obtained from the resulting metamodels of the simulation data. A 9 x 2 x 2 experiment consisting of 9 cases of simulation work, 2 levels of metamodel specification, and 2 levels of design fractionation were designed for 8 different configurations of MMk queues. The only observed statistic for this experiment was the average queue length. Simulation estimates for each configurations average queue length were calculated directly from the simulation data. In addition, the metamodels were fit to the simulation data and …
Proactive Monitoring Of Performance In Stochastic Communication Networks, John C. C. Van Hove
Proactive Monitoring Of Performance In Stochastic Communication Networks, John C. C. Van Hove
Theses and Dissertations
This research proposes several models for placing bounds on the expected values of some dynamic performance measures for computer communication networks with failing components. These models provide an understanding of expected network performance that is useful in the process of proactive performance monitoring and also in defining level of service agreements with network users. There were three objectives for this research. The first objective was to extend some existing models of steady-state stochastic network performance to a dynamic network flow representation in order to capture the dynamic nature of proactive monitoring. The second objective was to convert the extended absolute …
Analysis Of Thunder Combat Simulation Model, Timothy S. Webb
Analysis Of Thunder Combat Simulation Model, Timothy S. Webb
Theses and Dissertations
TAC THUNDER, or THUNDER, is a two-sided large scale computer simulation model that simulates air and ground combat, logistics, and limited airlift at the theater level. It is in use by several allied nations, major defense contractors, and various Department of Defense DoD analysis agencies. The objectives of this thesis effort were to examine the overall model variability, examine the model output for possible interrelationships, and examine the model sensitivity to input parameters. A univariate and multivariate analysis was performed to examine the first two objectives. The univariate analysis consisted of an analysis of the confidence intervals and replication requirements …
An Integer Solution Heuristic For The Arsenal Exchange Model (Aem), Daniel J. Green
An Integer Solution Heuristic For The Arsenal Exchange Model (Aem), Daniel J. Green
Theses and Dissertations
The Air Force Studies and Analyses Agency sought a method for converting the continuous solution produced by the Arsenal Exchange Model into a feasible integer solution. The current integerization method leaves weapons unused and targets uncovered and could be improved. In the method developed, the noninteger valued variables in the continuous solution are rounded down to the nearest integer to produce a truncated solution. An integer goal program is then used to reallocate the weapons and targets made available in the rounding process. The truncated solution is then combined with the solution of the integer goal program to produce a …
An Air Mission Planning Algorithm For A Theater Level Combat Model, Brian J. Griggs
An Air Mission Planning Algorithm For A Theater Level Combat Model, Brian J. Griggs
Theses and Dissertations
This thesis describes the development of an air mission planning algorithm for the Joint Staffs Future Theater Level Model FTLM. The overall problem scope was to develop an algorithm to handle major factors bearing on the combat mission planning problem while providing hook-ups for the FTLM architecture. Other aspects of the problem included finding the appropriate level of detail, developing a fast solving technique, and attempting to use existing data. The problem was handled by using some ideas from existing aircraft allocation algorithms and by adding some new techniques. The proposed air mission planning algorithm supplies the optimum degree of …
An Analysis Of Stopping Criteria In Artificial Neural Networks, Bruce Kostal
An Analysis Of Stopping Criteria In Artificial Neural Networks, Bruce Kostal
Theses and Dissertations
The goal of this study was to decide when to terminate training of an artificial neural network ANN. In pursuit of this goal, several characteristics of the ANN were monitored throughout ANN training classification error rate of the training set, testing set, or a weighted average of the two moving average classification error rate measurements of the difference between ANN output and desired output error sum of squares, total absolute error. or largest absolute error or ANN weight changes absolute weight change, squared weight change, or relative weight change. Throughout this research, the learning rate was held constant at 0.35. …
An Investigation Of Simulated Annealing Applied To Structural Optimization Problems, Richard C. Mceachin
An Investigation Of Simulated Annealing Applied To Structural Optimization Problems, Richard C. Mceachin
Theses and Dissertations
This thesis investigates the feasibility of using Simulated Annealing SA in structural optimization problems. The investigation involves solving benchmark structural optimization problems with an SA algorithm, and comparing its solutions to those found by four other optimizers. Overall, the analysis shows that SA has limited applicability in structural optimization. Two primary factors were found to adversely impact the performance of the SA algorithm in these problems. These factors are high dimensionality, and high levels of constraint. The difficulty involved in solving these problems with a random search increases exponentially with the number of dimensions. The number, and non-linearity, of the …
An Analysis Of Air Force Acquisition Engineering Officer's Perceptions Of The Adequacy Of Their Preparation For Management, Steven E. Woodruff
An Analysis Of Air Force Acquisition Engineering Officer's Perceptions Of The Adequacy Of Their Preparation For Management, Steven E. Woodruff
Theses and Dissertations
The purpose of this study was to determine how much time Air Force acquisition engineers spend in performing management functions, how those engineers spend in performing management functions, how those engineers perceive their management training, and which types of training contribute the most to managerial competency. The results from surveys of 215 acquisition engineers assigned to ASCEN, Wright-Patterson AFB, OH and their supervisors revealed that engineers do indeed spend substantial amounts of time performing management functions. Slightly more than half the engineers reported spending at least 50 of an average workday performing management functions. Over 53 of engineers responding to …
Synthetic Battlebridge: Information Visualization And User Interface Design Applications In A Large Virtual Reality Environment, Kirk G. Wilson
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
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 …
The Application Of Simulated Annealing To Stochastic Systems, Charles B. Warrender
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
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
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 …
Cost Constrained Improvements To The Military Retirement System, Cynthia A. Brown
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 …
Using Animation In The Validation Of Simulation Models, Michael L. Carpenter
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 …
Predicting The Productive Capacity Of Air Force Aerospace Ground Equipment Personnel Using Aptitude And Experience Measures, Robert S. Faneuff
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 …
Automating The Satellite Range Scheduling Process, Timothy D. Gooley
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 …