Open Access. Powered by Scholars. Published by Universities.®

Operational Research Commons™

Open Access. Powered by Scholars. Published by Universities.®

Theses and Dissertations

Discipline
Institution
Keyword
Publication Year

Articles 541 - 570 of 602

Full-Text Articles in Operational Research

A Model Of Global Positioning System (Gps) Master Control Station (Mcs) Operations, David N. Koster Dec 1992

A Model Of Global Positioning System (Gps) Master Control Station (Mcs) Operations, David N. Koster

Theses and Dissertations

The United States Air Force's Navstar Global Positioning System (GPS) provides high-accuracy space-based navigation and time distribution to suitably- equipped military and civilian users. The system consists of earth-orbiting satellites and a world-wide network of ground stations. A single operational control center, the GPS Master Control Station (MCS) monitors, maintains, and commands the GPS satellite constellation. The on-going deployment of the complete satellite constellation and recent changes in the operational crew structure may invalidate previously used planning and management paradigms. There is currently no analytical method for predicting the impact of these and other environmental changes on system parameters and …

Go to article

Retinal Modeling: Segmenting Motion From Spatio-Temporal Inputs Using Neural Networks, David E. Swanson Dec 1992

Retinal Modeling: Segmenting Motion From Spatio-Temporal Inputs Using Neural Networks, David E. Swanson

Theses and Dissertations

We applied two first-order, linear, time-varying, differential equations to the task of segmenting motion from sequences of images. The equations are modified Grossberg formulas for long-term and short-term memory models characterizing the neurotransmitter and cell-activity levels of a synapse and neuron. We described how a two layered, sensory, neural network can be built using the equations to simulate the amacrine neurons of the retina. The model is defined using adaptive input nodes (adaptive model) and is compared to a similar model without these nodes (O and G model). By replicating the basic amacrine neuron model to form both one- and …

Go to article

An Analysis Of Usspacecom's Space Surveillance Network (Ssn) Sensor Tasking Methodology, Jeff M. Berger, Joseph B. Moles, David G. Wisley Dec 1992

An Analysis Of Usspacecom's Space Surveillance Network (Ssn) Sensor Tasking Methodology, Jeff M. Berger, Joseph B. Moles, David G. Wisley

Theses and Dissertations

This study provides the basis for the development of a cost/benefit assessment model to determine the effects of alterations to the Space Surveillance Network (SSN) on orbital element (OE) set accuracy. It provides a review of current methods used by NORAD and the SSN to gather and process observations, an alternative to the current Gabbard classification method, and the development of a model to determine the effects of observation rate and correction interval on OE set accuracy. The proposed classification scheme is based on satellite J2 perturbations. Specifically, classes were established based on mean motion, eccentricity, and inclination Since J2 …

Go to article

A Methodology For Model Comparison Using The Theater Simulation Of Airbase Resources And All Mobile Tactical Air Force Models, Heston R. Hicks, Lawrence L. Long Sep 1992

A Methodology For Model Comparison Using The Theater Simulation Of Airbase Resources And All Mobile Tactical Air Force Models, Heston R. Hicks, Lawrence L. Long

Theses and Dissertations

This research compares the Theater Simulation of Airbase Resources (TSAR) model to the sortie generation (SORGEN) module of the AH Mobile Tactical Air Force (AMTAF) model, qualitatively and quantitatively, while concurrently developing and proving a model co methodology. The qualitative analysis compares the models' background and documentation, features and databases, and useability. The quantitative analysis statistically compares the models' estimates of sorties generated. For the quantitative study, eight variables are chosen and assigned high and low values for use in a 2' 1/4 fractional factorial experimental design. Equivalent input databases are developed from a TSAR F-15C database and pilot trials …

Go to article

An Analysis Of The Air Force Enlisted Performance Feedback System, Dee J. Jackson, Mark A. Ward Sep 1992

An Analysis Of The Air Force Enlisted Performance Feedback System, Dee J. Jackson, Mark A. Ward

Theses and Dissertations

This research evaluated the effectiveness of the enlisted evaluation performance feedback system. The Air Force created the feedback system because many airmen, especially those in lower ranks, did not know or did not understand their duties. Therefore, for the purpose of this study, effectiveness was defined as the degree to which the Air Force model mimicked the ideal feedback model as formulated by the researcher's analysis of the literature. The researchers found evidence that the new Air Force feedback system is an improvement over the old design. Under the old system, the only regulated means of providing feedback was a …

Go to article

Demonstrating The Effects Of Shop Flow Process Variability On The Air Force Depot Level Reparable Item Pipeline, Marvin A. Arostegui Jr., Jon A. Larvick Sep 1992

Demonstrating The Effects Of Shop Flow Process Variability On The Air Force Depot Level Reparable Item Pipeline, Marvin A. Arostegui Jr., Jon A. Larvick

Theses and Dissertations

This study investigated the effects of reducing the mean processing time and variability in the Shop Flow Segment of the Depot Level Reparable Item pipeline. The measure of interest was the average number of units in the pipeline of a particular type of item (referred to as the average pipeline contents). A literature review revealed that process variability in the pipeline has an impact on its effective operation and cost. A simulation model was developed to determine if reducing mean processing time and/or variability in the Shop Flow Segment would result in a reduction in the average pipeline contents. The …

Go to article

The Theory Of Constraints Applied To Project Scheduling: The Critical Chain Concept Defined, Andrew D. Ingram, Paul E. Scherer Sep 1992

The Theory Of Constraints Applied To Project Scheduling: The Critical Chain Concept Defined, Andrew D. Ingram, Paul E. Scherer

Theses and Dissertations

This research applies the Theory of Constraints' principles to a project management environment. The Constraint Theory developed by Dr. Eliyahu M. Goldratt has been successfully applied in many manufacturing settings. Researchers are now beginning to apply Theory of Constraints' principles and techniques outside the manufacturing environment. Specific objectives of this research effort include: to develop and demonstrate a resource constrained project scheduling algorithm based on the Theory of Constraints' principles and techniques: to perform a detailed comparison of the manufacturing and project scheduling environments designed to support algorithm development; and to lay the foundation for additional research in this area …

Go to article

A Method For Determining Schedule Delay Information In A Channel Cargo Route Network Schedule, Justin E. Moul Jun 1992

A Method For Determining Schedule Delay Information In A Channel Cargo Route Network Schedule, Justin E. Moul

Theses and Dissertations

This research develops a method for measuring schedule effectiveness by determining the amounts of enroute, cargo delay caused by a given aircraft mission schedule. The method is designed to generate information which helps identify flights for which different scheduling might decrease overall cargo delay in the entire network, given that all non-scheduling factors are held constant. The research uses a simplified twelve-airport cargo route network to test the methodology.

Go to article

Strategic Deterrence In The Post-Start Era, David C. Mccormick Apr 1992

Strategic Deterrence In The Post-Start Era, David C. Mccormick

Theses and Dissertations

With the Soviet Union's fall there have been widespread calls for drastic reductions in the United States military's strategic nuclear forces. Although a major threat to the United States has been greatly reduced, the number of strategic targets will not decrease as rapidly as the number of available weapons. This research considers how the United States should think about strategic forces in the rapidly changing world order of the 1990s. An extensive literature review of deterrence concepts and conventional weapons capabilities is conducted with special attention paid to the role that precision guided munitions played in the 1991 Persian Gulf …

Go to article

Transformation Of Combat Data In Support Of Battle Trace, Hyoung-Kyu Choi Mar 1992

Transformation Of Combat Data In Support Of Battle Trace, Hyoung-Kyu Choi

Theses and Dissertations

The purpose of this study was to find an appropriate way of characterizing battle data as a function of time. This study was initially designed to remove the numerical instability problem cited in Barr's battle trace methodology as suggested by TRAC-MTRY. The research focused on the instability problem and identifying/recommending a technique that improved the efficiency of computation, and enhanced an analyst's ability to meaningfully interpret the battle trace. Two Lanchester's Square Law based methodologies are introduced and analyzed. The results of this analysis indicate that the battle trace of a constant value generated by Lanchester's Square Law integration seemed …

Go to article

Visual Information Processing And Response Time In Traffic-Signal Cognition, Hasan H. Demirarslan Mar 1992

Visual Information Processing And Response Time In Traffic-Signal Cognition, Hasan H. Demirarslan

Theses and Dissertations

In man-machine design, it is important to quantify the reaction time components instead of simply determining the lump-sum reaction time to stimulus. The primary purpose of this thesis was to investigate the reaction time components, such as visual perception and muscle response time, and to quantify them by separating from their aggregated sum. The prime example, traffic-signal cognition simulation was used to examine human reaction time to signal change. With a modified computer program that stimulates the driver's approach to the intersection, we measured the subject's reaction times and examined behavioral patterns. Twelve subjects were involved in the experiment. A …

Go to article

Multilayer Perceptrons For Classification, Lisa M. Belue Mar 1992

Multilayer Perceptrons For Classification, Lisa M. Belue

Theses and Dissertations

Techniques for training, testing, and validating multilayer perceptrons are thoroughly examined. Results obtained using perceptrons are compared and contrasted with two multivariate discriminant analysis techniques- logistic regression and k neighbor. Methods for determining significant input features are investigated and a procedure for examining the confidence to place in the significance of these features is developed. Procedures to evaluate the applicability of high-order feature inputs are examined. These methods and procedures are applied to two very different applications. The first application concerns the prediction of Air Force pilot retention/separation rates for input to force projection models. The second application concerns the …

Go to article

Causal Univariate Spatial-Temporal Autoregressive Moving Averages (Starma) Modelling Of Target Information To Generate Tasking Of A World-Wide Sensor System, Kelly A. Greene Mar 1992

Causal Univariate Spatial-Temporal Autoregressive Moving Averages (Starma) Modelling Of Target Information To Generate Tasking Of A World-Wide Sensor System, Kelly A. Greene

Theses and Dissertations

The Department of Defense employs a resource limited world-wide sensor system to detect certain events of interest. The purpose of this research was to establish a methodology using a univariate causal STARMA model for forecasting the relative probability of an event occurring in a geographical location during a time block of the day. These relative probabilities are used as input for a tasking model that assigns the scarce sensor resources so as to optimize the detection of these events. The STARMA model is appropriate for forecasting the relative probabilities because a definite temporal relationship and a definite spatial relationship exists …

Go to article

Developing Cmmca Flight Profiles For Cruise Missile Tracking, Andrew C. Hachman Mar 1992

Developing Cmmca Flight Profiles For Cruise Missile Tracking, Andrew C. Hachman

Theses and Dissertations

The Air Force has recently acquired two aircraft dedicated for cruise missile tracking. These aircraft, known as the Cruise Missile Mission Control Aircraft (CMMCA), are responsible for collecting data from the missile and United States. Due to tracking and positively controlling the missile during live fire testing over the western the limited tracking radar range and the flight characteristics of the CMMCA, tracking cruise missiles through complex maneuvers is not always possible. A FORTRAN optimization, based on flight simulation and optimal control theory, was written in a prior thesis effort in order to determine optimal CMMCA flight profiles for tracking …

Go to article

An Analysis Of Escort Formations, Mustafa Ilhan Mar 1992

An Analysis Of Escort Formations, Mustafa Ilhan

Theses and Dissertations

This study used computer simulation to investigate escort fighter formations unknown interceptor threat environment. A USAF computer simulation model, TAC, was used to simulate air combat between the escorts and the interceptors in several different combat scenarios. The escort formations were defined by the vertical and horizontal distances of the escort fighters from the main strike body. Interceptors were characterized as one of two types of fighters with dissimilar aircraft frames and missile firing ranges. A central composite design was used to mathematically model the effect of escort formations and interceptor type on the survivability of the bombers and escorts. …

Go to article

Automating The Weekly Flight Scheduling Process At The Usaf Test Pilot School, Gary G. Foster Mar 1992

Automating The Weekly Flight Scheduling Process At The Usaf Test Pilot School, Gary G. Foster

Theses and Dissertations

This study investigated different scheduling solution approaches that could be automated and applied at the USAF Test Pilot School (TPS). Currently at the TPS, flight schedules are manually developed on a daily basis. Weekly flight schedules are not developed due to the large quantity of data that must be processed to develop a flight schedule for an entire week. A weekly flight scheduling approach would reduce the occurrence of scheduling problems and unbalanced resource utilization, both of which are often the result of a daily flight scheduling approach. In addition, posting a flight schedule for the entire week would improve …

Go to article

An A Priori Multiobjective Optimization Model Of A Search And Rescue Network, Joseph C. Imsand Jr. Mar 1992

An A Priori Multiobjective Optimization Model Of A Search And Rescue Network, Joseph C. Imsand Jr.

Theses and Dissertations

The purpose of this study was to determine the most robust frequency assignment for a search and rescue network. The focus was to assign weights to the transmitter areas of the network to determine which weight sequence produced the most robust frequency assignment. The DoD furnished weight sequences for twelve two-hour time blocks. These weight sequences were compared to a weight sequence with all weights having equal value. Network and linear programming were used to-solve this problem and generate frequency assignments for all weight sequences. Classical and tolerance sensitivity analysis were used to analyze the frequency assignments generated by the …

Go to article

An Investigation Of Modifications To The Tac Campaign Model, Efgan Denguer Mar 1992

An Investigation Of Modifications To The Tac Campaign Model, Efgan Denguer

Theses and Dissertations

This research investigates the cost and budget modifications to Mixmaster which is an aggregate version of the Theater Attack Model (TAM). Seven simple cost employment methods, a goal programming approach, a probabilistic approach for determining cost coefficients, and goal programming version of that probabilistic approach were applied to Mixmaster. Also, Mixmaster was enhanced with an additional leading constraint to incorporate the Air Force tactical considerations in a campaign scenario. The results favor the advantages of the goal programming approaches. In addition, the probabilistic approach introducing the time factor in the computations promises more accurate results, given that the required parameters …

Go to article

An Analysis Of The Endurance Of Mobile Satellite Command And Control Systems, Steven O. Brown Mar 1992

An Analysis Of The Endurance Of Mobile Satellite Command And Control Systems, Steven O. Brown

Theses and Dissertations

This study investigated the endurance of a single deployed generic mobile space (GMS) command and control (C2) system. Specifically, factors which affect overall system performance were examined. The analysis began with the development of a simulation model for a GMS C2 system. Optimal settings of factor levels were determined by using the model to find peak system endurance and availability. Factors set were field support vehicle (FSV) access, numbers of maintenance personnel, and numbers of spare components available. After optimum values were chosen for these factors, an experimental design was conducted to determine factor effect between maintenance manpower and the …

Go to article

Modular Simulation Of Hei Fragments And Blast Pressure, Gordon L. Galloway Mar 1992

Modular Simulation Of Hei Fragments And Blast Pressure, Gordon L. Galloway

Theses and Dissertations

The fragmentation and blast pressure of High Explosive Incendiary projectiles are major causes of aircraft fuel fires. Because Halon 1301 is being banned from DoD use as a fire suppressant, alternative fire suppressants must be developed and tested. These new suppressants must counteract the fire directly or eliminate one or more of the factors which cause the fire. To this end, this thesis takes a detailed look at the HEI processes that lead to a fire. A comprehensive review of the current knowledge and understanding of these processes is presented. In addition, hypothesized dependencies between the various processes are stated. …

Go to article

Confidence Interval Estimation For Output Of Discrete-Event Simulations Using The Kalman Filter, Randall B. Howard Mar 1992

Confidence Interval Estimation For Output Of Discrete-Event Simulations Using The Kalman Filter, Randall B. Howard

Theses and Dissertations

Discrete-event simulation is computer modeling of stochastic, dynamic systems. The Kalman filter is a Bayesian stochastic estimation algorithm. Because of the correlated nature of simulation output, it is difficult to apply the methods of classical statistics directly when constructing confidence intervals of discrete-event simulation parameters. Through the determination of a dynamics equation and application of the Kalman filter to simulation output data, three new confidence interval construction techniques have been developed. One technique obtains an estimate of the mean value and its associated variance from an estimated Kalman filter. The second technique utilizes Multiple Model Adaptive Estimation (MMAE) techniques to …

Go to article

Effects Of Facility Configurations And Scheduling Techniques On Aircraft Throughput For Warner Robins Alc Paint/Depaint Facilities, David V. Mcelveen Mar 1992

Effects Of Facility Configurations And Scheduling Techniques On Aircraft Throughput For Warner Robins Alc Paint/Depaint Facilities, David V. Mcelveen

Theses and Dissertations

The purpose of this research was to determine the effects of configuration options and dispatching rules on aircraft throughput for the WR- ALC paint/depaint facilities. A simulation model was constructed and used for this analysis as the primary means to conduct the research. The dispatching rules considered were first come first served, largest number in queue, shortest processing time, and a look ahead heuristic. Due to a reduction in the number of paint aircraft, no configuration option differing from the baseline significantly affected aircraft throughput. Dispatching rules were also found to produce no significant differences on aircraft throughput. Configuration options …

Go to article

Quantifying The Impact Of The Acquisition Professional Development Program Certification Requirements On The Air Force Institute Of Technology, Paul A. Nicholson Mar 1992

Quantifying The Impact Of The Acquisition Professional Development Program Certification Requirements On The Air Force Institute Of Technology, Paul A. Nicholson

Theses and Dissertations

The purpose of this research is to determine the impact of implementing the Acquisition Professional Development Program on the Air Force Institute of Technology. APDP is part of a DOD-wide effort to decrease inefficiency in the procurement process. The program encompasses a tri-level certification process based on experience, training, and educational standards. APDP serves as a guideline for professional development of acquisition personnel from entry to senior level management. Many of the courses required for certification are offered through AFIT School of Systems and Logistics. Integrating the new educational requirements as a standard for career development is expected to produce …

Go to article

A Sensitivity Analysis Of Circular Error Probable Approximation Techniques, Peter Puhek Mar 1992

A Sensitivity Analysis Of Circular Error Probable Approximation Techniques, Peter Puhek

Theses and Dissertations

Several algebraic CEP estimates models were examined in this study. Each assumes 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 the parameters of sample size, bias, correlation, and ellipticity. The accuracy of each model is expressed in terms of relative error, and the parameter regions in which a certain method dominated as the most accurate were noted. In general, it was found that bias was the most significant parameter in determining the best CEP method. A simple method, based on the …

Go to article

An Improved Scheduling Algorithm For Eglin Afb Test Ranges, Jeffrey S. Antes Mar 1992

An Improved Scheduling Algorithm For Eglin Afb Test Ranges, Jeffrey S. Antes

Theses and Dissertations

This research develops an algorithm that integrates into an existing computerized scheduling system to improve the mission scheduling function for Eglin AFB test ranges. The primary objective of this research was to design an improved computerized scheduling aid. The measure of performance for this approach is the number of missions scheduled using this aid as compared to current Eglin capabilities. Constructive heuristics are used in the algorithm to schedule missions according to critical resource groups while ensuring mission priority is not violated. The success of this new interactive scheduling algorithm is measured against a schedule produced by the current computer …

Go to article

Gettysburg: An Analysis Of The Training Value Of Commercial Models, Jude C. Fernan Mar 1992

Gettysburg: An Analysis Of The Training Value Of Commercial Models, Jude C. Fernan

Theses and Dissertations

This study investigated the possibilities of using commercial combat models/war games dealing with the battle of Gettysburg as aids for the training of soldiers and leaders in the military. With the downsizing of the military and the high cost of training, there exists a need to reduce training costs while not affecting the quality of training. The military employs various military models to assist in training but has yet to fully tap the wealth of commercial combat models. One reason may be the lack of an investigative analysis into the soundness and applicability of commercial combat models to military training. …

Go to article

A Decision-Theoretic Approach To Recommending Action In The Air-To- Ground Aircraft Of The Future, Garrison H. Flemings Mar 1992

A Decision-Theoretic Approach To Recommending Action In The Air-To- Ground Aircraft Of The Future, Garrison H. Flemings

Theses and Dissertations

Designers of air-to-ground fighters of the future should consider including decision support systems to relieve pilots of some of the present workload. Those decision support systems should use utility theory. This work reviews two techniques of utility theory (decision trees and influence diagrams) and a new technique due to Morlan (probability ratio nets). The work includes a proposed structure for action recommendation systems in air-to-ground fighters of the future. The work describes an implementation of probability ratio nets. The work demonstrates the value of decision theory to air-to-ground fighters of the future by way of solving an example problem and …

Go to article

Saber: Airland Combat Training Model Credibility Assessment And Methodology, David L. Scagliola Mar 1992

Saber: Airland Combat Training Model Credibility Assessment And Methodology, David L. Scagliola

Theses and Dissertations

Saber is a theater-level, airland combat training model, designed by a number of computer science and engineering students and faculty at the Air Force Institute of Technology (AFIT). Saber is intended to replace the Agile model, which is currently used at the Air Force Wargaming Center, Maxwell AFB, Alabama for Theater Warfare Exercise (TWX) training purposes. This thesis focuses on the progress made towards generating the Saber training model, its ability to meet the objectives specified by the Wargaming Center, and its ability to represent actual combat. Specifically, this thesis is directed towards characterizing, establishing a credibility assessment, and developing …

Go to article

A Response Surface Methodology Study Of Ferroelectric Memory Devices, Kevin C. Smith Mar 1992

A Response Surface Methodology Study Of Ferroelectric Memory Devices, Kevin C. Smith

Theses and Dissertations

Fatigue in ferroelectric memory devices was studied. The application of fatigue pulses to a ferroelectric sample was controlled by the RT-66 Ferroelectric Tester, a variation of the Sawyer-Tower circuit. The RT-66 also controlled data collection following the fatiguing process. Seven variables were evaluated for their potential- affect on fatigue. A sequence of fatigue tests, which varied the settings of these variables, was developed using Response Surface Methodology (RSM) experimental designs. Least-squares regression models were developed once a particular RSM set of design experiments was completed. These models were evaluated using RSM tools, and the analysis of these models allowed the …

Go to article

Optimization Of Stochastic Response Surfaces Subject To Constraints With Linear Programming, Robert G. Harvey Mar 1992

Optimization Of Stochastic Response Surfaces Subject To Constraints With Linear Programming, Robert G. Harvey

Theses and Dissertations

This research investigated an alternative to the traditional approaches of optimizing a stochastic response surface subject to constraints. This research investigated the bias in the expected value of the solution, possible alternative decision variable settings, and a method to improve the solution. A three step process is presented to evaluate stochastic response surfaces subject to constraints. Step 1 is to use a traditional approach to estimate the response surface and a covariance matrix through regression. Step 2 samples the objective function of the linear program (i.e., response surface) and identifies the extreme points visited. Step 3 presents a method to …

Go to article

First Prev Next Last