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Articles 271 - 300 of 602

Full-Text Articles in Operational Research

An Efficient Metaheuristic For Dynamic Network Design And Message Routing, Robert B. Hartlage Mar 2007

An Efficient Metaheuristic For Dynamic Network Design And Message Routing, Robert B. Hartlage

Theses and Dissertations

The implementation of Net-centric warfare presents major challenges in terms of effectively and efficiently delivering critical information across the Global Information Grid. In many cases, the amount of information requested will exceed the capabilities of the network. One challenge is to dynamically design the network (assign transceivers) to maximize the amount of required information that can be transmitted and the quality of service for those transmissions - to best implement the communications tasking order. The problem is as follows: given a list of required message traffic, to include source, destination, size, and priority, design the network to maximize the delivery …


Updating Optimal Decisions Using Game Theory And Exploring Risk Behavior Through Response Surface Methodology, Jeremy D. Jordan Mar 2007

Updating Optimal Decisions Using Game Theory And Exploring Risk Behavior Through Response Surface Methodology, Jeremy D. Jordan

Theses and Dissertations

This thesis utilizes game theory within a framework for updating optimal decisions based on new information as it becomes available. Methodology is developed that allows a decision maker to change his perceived optimal policy based on available knowledge of the opponents strategy, where the opponent is a rational decision maker or a random component nature. Utility theory is applied to account for the different risk preferences of the decision makers. Furthermore, response surface methodology is used to explore good risk strategies for the decision maker to approach each situation with. The techniques are applied to a combat scenario, a football …


Mathematical Programming Model For Fighter Training Squadron Pilot Scheduling, Thomas M. Newlon Mar 2007

Mathematical Programming Model For Fighter Training Squadron Pilot Scheduling, Thomas M. Newlon

Theses and Dissertations

The United States Air Force fighter training squadrons build weekly schedules using a long and tedious process. Very little of this process is automated and optimality of any kind is nearly impossible. Schedules are built to a feasible condition only to be changed with consideration of Wing level requirements. Weekly flying schedules are restricted by requirements for crew rest, days since a pilot's last sortie, sorties in the last 30 days, and sorties in the last 90 days. By providing a scheduling model to the pilot charged with creating the schedule, valuable pilot hours could be spent in the cockpit, …


Examining Clandestine Social Networks For The Presence Of Non-Random Structure, Joshua S. Seder Mar 2007

Examining Clandestine Social Networks For The Presence Of Non-Random Structure, Joshua S. Seder

Theses and Dissertations

This thesis develops a tractable, statistically sound hypothesis testing framework for the detection, characterization, and estimation of non-random structure in clandestine social networks. Network structure is studied via an observed adjacency matrix, which is assumed to be subject to sampling variability. The vertex set of the network is partitioned into k mutually exclusive and collectively exhaustive subsets, based on available exogenous nodal attribute information. The proposed hypothesis testing framework is employed to statistically quantify a given partition's relativity in explaining the variability in the observed adjacency matrix relative to what can be explained by chance. As a result, valuable insight …


Change-Point Methods For Overdispersed Count Data, Brian A. Wilken Mar 2007

Change-Point Methods For Overdispersed Count Data, Brian A. Wilken

Theses and Dissertations

A control chart is often used to detect a change in a process. Following a control chart signal, knowledge of the time and magnitude of the change would simplify the search for and identification of the assignable cause. In this research, emphasis is placed on count processes where overdispersion has occurred. Overdispersion is common in practice and occurs when the observed variance is larger than the theoretical variance of the assumed model. Although the Poisson model is often used to model count data, the two-parameter gamma-Poisson mixture parameterization of the negative binomial distribution is often a more adequate model for …


An Adaptive Tabu Search Heuristic For The Location Routing Pickup And Delivery Problem With Time Windows With A Theater Distribution Application, Robert E. Burks Jr. Sep 2006

An Adaptive Tabu Search Heuristic For The Location Routing Pickup And Delivery Problem With Time Windows With A Theater Distribution Application, Robert E. Burks Jr.

Theses and Dissertations

The time constrained pickup and delivery problem (PDPTW) is a problem of finding a set of routes for a fleet of vehicles in order to satisfy a set of transportation requests. Each request represents a user-specified pickup and delivery location. The PDPTW may be used to model many problems in logistics and public transportation. The location routing problem (LRP) is an extension of the vehicle routing problem where the solution identifies the optimal location of the depots and provides the vehicle schedules and distribution routes. This dissertation seeks to blend the PDPTW and LRP areas of research and formulate a …


Modeling A Reparable Supply Chain And Applying Cpfr Concepts, Sandra A. Mayhall Jun 2006

Modeling A Reparable Supply Chain And Applying Cpfr Concepts, Sandra A. Mayhall

Theses and Dissertations

The Air Force supply chain includes parts required to build, fix, or maintain aircraft delivered to the warfighter to carry out missions. Industry has shown that following Collaborative Planning, Forecasting, and Replenishment (CPFR) concepts, particularly reducing inventory through accurate demand forecasts, has increased profits in part by lowering the holding costs of inventory and increasing sales. This is analogous to the Air Force increasing aircraft availability. There is scant evidence that demand forecasts generated at any level in the Air Force are shared with the intent of coordinating replenishment. This thesis uses a simple discrete-event stochastic simulation model to show …


Reducing Uncertainty In Effects-Based Operations, Wilburn B. Mclamb Mar 2006

Reducing Uncertainty In Effects-Based Operations, Wilburn B. Mclamb

Theses and Dissertations

Known as the fog of war, uncertainty has been prevalent in the conduct of military operations throughout human history. Intelligence collection efforts are tasked to reduce this uncertainty through the collection of information. Utilizing Shannon's entropy as a measure of the expected information gain due to an intelligence collection effort, a methodology is developed to prioritize and allocate intelligence assets in an efficient manner. Incorporated in this methodology are target priority and the requirement to reassess dynamic targets. The application area for the methodology is Effects-Based Operations. A generalized state model is developed to conduct adversary system-of-systems analysis. This model …


Modeling Network Centric Warfare (Ncw) With The System Effectiveness Analysis Simulation (Seas), Jason B. Honabarger Mar 2006

Modeling Network Centric Warfare (Ncw) With The System Effectiveness Analysis Simulation (Seas), Jason B. Honabarger

Theses and Dissertations

Significant technological advances over the past few decades have fueled the continual and rapid development of an information-based world. Network Centric Warfare (NCW) has become the buzzword of the young millennium within the Department of Defense (DoD) and is quickly becoming a popularly shared vision and rallying cry for force transformation among United States military leaders. An essential element in fully implementing this network-centric way of thinking is to develop useful measures to help gauge the effectiveness and efficiency of both our military networks and our strategic NCW doctrine. The goal of this research is first to provide a comprehensive …


Using Agent-Based Modeling To Search For Elusive Hiding Targets, Jeffrey E. Rucker Mar 2006

Using Agent-Based Modeling To Search For Elusive Hiding Targets, Jeffrey E. Rucker

Theses and Dissertations

The SCUD hunt problem that emerged during Operation Desert Storm has become a source of great interest to major commands like Air Combat Command. One of the metrics used to measure the effectiveness of our operations in a SCUD hunt is time to detect and target. We use the agent-based System Effectiveness and Analysis Simulation (SEAS) to provide a simulation environment in which all the elements of a SCUD hunt mission can adequately be modeled. Our Blue Force agents are modeled as multirole fighters, satellites and unmanned aerial vehicles (UAV) with various sensor capabilities. The Red Force agents are modeled …


Modeling Urban Warfare: Joint Semi-Automated Forces In Urban Resolve, Alexander B. Anastasiou Mar 2006

Modeling Urban Warfare: Joint Semi-Automated Forces In Urban Resolve, Alexander B. Anastasiou

Theses and Dissertations

The United States military is performing operations in urban environments with increasing frequency. Current Department of Defense doctrine is poorly suited to train and equip today's warriors with the tools and experience necessary to fight and win in modern sprawling cities. In order to "close the gap," the U.S. Joint Forces Command's Joint Experimentation Directorate led an effort to run a massively distributed simulation of a synthetic urban environment utilizing human-in-the-loop operators called URBAN RESOLVE. The synthetic environment simulated the city of Jakarta with over 1,000,000 buildings and structures and over 120,000 civilian entities. A Red force retreated into the …


An Epidemiological Approach To Terrorism, Kjirstin A. Bentson Mar 2006

An Epidemiological Approach To Terrorism, Kjirstin A. Bentson

Theses and Dissertations

There are many types of models for counterterrorism, explaining different problems that the military faces in the fight against terrorism. This thesis proposes that one of the fundamental assumptions underlying existing models of counterterrorism is that the struggle with terrorists can be understood as a war in the traditional sense of the term. We propose to rethink the struggle against terrorism as a fight against an infection. The epidemic of terrorist ideology within part of the world is a result, from this perspective, of the infectiousness of that ideology. Using the insights of the field of the epidemiology of ideas, …


Optimal Periodic Inspection Of A Stochastically Degrading System, Timothy B. Booher Mar 2006

Optimal Periodic Inspection Of A Stochastically Degrading System, Timothy B. Booher

Theses and Dissertations

This thesis develops and analyzes a procedure to determine the optimal inspection interval that maximizes the limiting average availability of a stochastically degrading component operating in a randomly evolving environment. The component is inspected periodically, and if the total observed cumulative degradation exceeds a fixed threshold value, the component is instantly replaced with a new, statistically identical component. Degradation is due to a combination of continuous wear caused by the component's random operating environment, as well as damage due to randomly occurring shocks of random magnitude. In order to compute an optimal inspection interval and corresponding limiting average availability, a …


Discrete Event Simulation Model Of The Ground Maintenance Operations Cycle Of A Reusable Launch Vehicle, John T. Pope Iii Mar 2006

Discrete Event Simulation Model Of The Ground Maintenance Operations Cycle Of A Reusable Launch Vehicle, John T. Pope Iii

Theses and Dissertations

The Air Force uses a family of expendable launch vehicles to meet its spacelift needs. Unfortunately, this method is not responsive: months of preparation are typically required and launch costs are high. Consequently, the Air Force seeks a reusable military launch vehicle that can be launched inexpensively and quickly regenerated between flights. Air Force Research Laboratory personnel desire a tool to help evaluate candidate designs and perform tradeoff studies necessary to acquire a launch vehicle that will achieve Air Force goals. The objective of this research was first to develop a conceptual model of maintenance operations needed to regenerate a …


A Discrete Event Simulation Model For Evaluating Air Force Reusable Military Launch Vehicle Prelaunch Operations, Adam T. Stiegelmeier Mar 2006

A Discrete Event Simulation Model For Evaluating Air Force Reusable Military Launch Vehicle Prelaunch Operations, Adam T. Stiegelmeier

Theses and Dissertations

As the control and exploitation of space becomes more important to the United States military, a responsive spacelift capability will become essential. Responsive spacelift could be defined as the ability to launch a vehicle within hours or days from the time a launch order is given, instead of the weeks or months it takes currently. As the Air Force contemplates moving toward a reusable military launch vehicle (RMLV) capability, it faces key design and ground processing decisions that will affect the vehicle regeneration timeline. This thesis develops a computer simulation model that mimics RMLV prelaunch operations-those activities that take place …


Combining Quality Of Service And Topology Control In Directional Hybrid Wireless Networks, Michael C. Erwin Mar 2006

Combining Quality Of Service And Topology Control In Directional Hybrid Wireless Networks, Michael C. Erwin

Theses and Dissertations

Recent advancements in information and communications technology are changing the information environment in both quantitative and qualitative measures. The developments in directional wireless capabilities necessitate the ability to model these new capabilities, especially in dynamic environments typical of military combat operations. This thesis establishes a foundation for the definition and consideration of the unique network characteristics and requirements introduced by this novel instance of the Network Design Problem (NDP). Developed are a Mixed-Integer Linear Program (MILP) formulation and two heuristic strategies for solving the NDP. A third solution strategy using the MILP formulation with a degree-constrained Minimum Spanning Tree starting …


Optimizing Mean Mission Duration For Multiple-Payload Satellites, John A. Flory Mar 2006

Optimizing Mean Mission Duration For Multiple-Payload Satellites, John A. Flory

Theses and Dissertations

This thesis addresses the problem of optimally selecting and specifying satellite payloads for inclusion on a satellite bus to be launched into a constellation. The objective is to select and specify payloads so that the total lifetime utility of the constellation is maximized. The satellite bus is limited by finite power, weight, volume, and cost constraints. This problem is modeled as a classical knapsack problem in one and multiple dimensions, and dynamic programming and binary integer programming formulations are provided to solve the problem. Due to the computational complexity of the problem, the solution techniques include exact methods as well …


A Risk Assessment Methodology For Divesting Military Capabilities To Allied Nations, Jason A. Gastelum Mar 2006

A Risk Assessment Methodology For Divesting Military Capabilities To Allied Nations, Jason A. Gastelum

Theses and Dissertations

The United States spent over $400 billion dollars on national defense in 2005. Even with support for the war on terrorism still strong, it is doubtful that the U.S. can sustain such a level of defense investment. One strategy to offset the increasing burden of defense spending is to divest the procurement and/or sustainment of individual defense capabilities to allied nations. The decision to divest any capability, however, introduces risk. This thesis presents a methodology to quantify the risk of the decision to divest a military capability to an allied nation, where risk is defined as the set of risk …


Classification Characteristics Of Carbon Nanotube Polymer Composite Chemical Vapor Detectors, Huynh A. Hinshaw Mar 2006

Classification Characteristics Of Carbon Nanotube Polymer Composite Chemical Vapor Detectors, Huynh A. Hinshaw

Theses and Dissertations

The first step in combating a chemical weapons threat is contamination avoidance. This is accomplished by the detection and identification of chemical agents. The Air Force has several instruments to detect chemical vapors, but is always looking for lighter, faster, and more accurate technology for a better capability. This research is focused on using carbon nanotube polymer composite sensors for chemical detection. More specifically, models are developed to classify three sets of sensor data according to vapor using various multivariate techniques. Also, prediction models of a mixed sensor output are developed using neural networks and regression analysis. The classifiers developed …


Analysis Of Patient Information: An Empirical Modeling Approach, Tony A. Murphy Mar 2006

Analysis Of Patient Information: An Empirical Modeling Approach, Tony A. Murphy

Theses and Dissertations

With rising costs and increasing complexities, many hospitals seek to better understand the intricate details of their operations. Increasingly, these organizations have a strong desire to accurately predict the resources required to effectively treat their patient load. This research investigates patient length-of-stay in a hospital neurological unit using an empirical modeling approach. Factors significantly affecting patient length of stay were identified and used to construct a regression model. The predictive model provides hospital decision makers with a compact tool to input what-if scenarios and predict future patient treatment lengths, thus, allowing the hospital to properly allocate resources.


A Multi-Pass Construction Heuristic For The Aggregated Airlift Problem, Stephen T. O'Leary Mar 2006

A Multi-Pass Construction Heuristic For The Aggregated Airlift Problem, Stephen T. O'Leary

Theses and Dissertations

To support the capabilities for precision strike, close air support, intelligence, surveillance, reconnaissance, air mobility and air refueling the Air Force has over 26,000 Airmen deployed from over 80 military installations to Forward Operating Locations (FOLs) in over 21 countries. This research creates a multi-pass construction heuristic to solve the aggregated airlift problem associated with the transportation of these 26,000 deployed Airmen. We are given a Time Phased Force Deployment Document (TPFDD) containing a list of personnel scheduled for deployment, their base of origin, Point of Debarkation (POD), FOL, and Required Delivery Date (RDD). The goal is to aggregate the …


Optimization Of A Multi-Echelon Repair System Via Generalized Pattern Search With Ranking And Selection: A Computational Study, Derek D. Tharaldson Mar 2006

Optimization Of A Multi-Echelon Repair System Via Generalized Pattern Search With Ranking And Selection: A Computational Study, Derek D. Tharaldson

Theses and Dissertations

With increasing developments in computer technology and available software, simulation is becoming a widely used tool to model, analyze, and improve a real world system or process. However, simulation in itself is not an optimization approach. Common optimization procedures require either an explicit mathematical formulation or numerous function evaluations at improving iterative points. Mathematical formulation is generally impossible for problems where simulation is relevant, which are characteristically the types of problems that arise in practical applications. Further complicating matters is the variability in the simulation response which can cause problems in iterative techniques using the simulation model as a function …


Strategic Airlift En Route Analysis To Support The Global War On Terrorism Using A Value Focused Thinking Approach, Marykathryn W. Tharaldson Mar 2006

Strategic Airlift En Route Analysis To Support The Global War On Terrorism Using A Value Focused Thinking Approach, Marykathryn W. Tharaldson

Theses and Dissertations

The Global War on Terrorism (GWOT) has yielded new challenges to the United States' strategic airlift infrastructure. The network of en-route airfields that serve as refueling and maintenance stops were designed primarily to service relatively static Cold War requirements. However, the GWOT has resulted in the need for an infrastructure that is responsive to a highly dynamic environment. This research uses a "value focused" methodology to identify en-route airfield locations that simultaneously maximize cargo throughput capability while possessing a high degree of adaptability to volatile cargo delivery requirements.


A Methodology For Performing Effects-Based Assessments, Benjamin A. Thoele Mar 2006

A Methodology For Performing Effects-Based Assessments, Benjamin A. Thoele

Theses and Dissertations

In order to bring the doctrine of Effects-Based Operations (EBO) into a fully operational capability, Effects-Based Assessment (EBA) must provide relevant insight to the commander and his planning staff. Assessments of an effects-based plan and execution must include an assessment of the effects of a campaign on the enemy in addition to an assessment of the accomplishment of friendly actions taken to achieve the desired effects. Determining the effects of a campaign requires an analysis of the dynamics of the enemy systems. EBA must be able to recognize the states of the enemy's systems as the system states change over …


Assessing Resource Value And Relationships Between Objectives In Effects-Based Operations, Robert D. Jones Mar 2006

Assessing Resource Value And Relationships Between Objectives In Effects-Based Operations, Robert D. Jones

Theses and Dissertations

The purpose of this research was developing techniques to calculate the value of a resource within the context of campaign objectives, to identify competing objectives, and to identify conflicting objectives to improve a commander’s ability to allocate limited resources. A methodology was developed to express a campaign’s objective hierarchy in terms of a set of desired end states for the campaign’s system of systems. Value theory was used to identify the resource's value in terms of the direct and indirect effects that are produced to achieve the campaign’s objectives. Binding resource constraints within an integer program were used to identify …


Combat Identification With Sequential Observations, Rejection Option, And Out-Of-Library Targets, Timothy W. Albrecht Sep 2005

Combat Identification With Sequential Observations, Rejection Option, And Out-Of-Library Targets, Timothy W. Albrecht

Theses and Dissertations

This research extends a mathematical framework to select the optimal sensor ensemble and fusion method across multiple decision thresholds subject to warfighter constraints for a combat identification (CID) system. The formulation includes treatment of exemplars from target classes on which the CID system classifiers are not trained (out-of-library classes) and enables the warfighter to optimize a CID system without explicit enumeration of classifier error costs. A time-series classifier design methodology is developed and applied, yielding a multi-variate Gaussian hidden Markov model (HMM). The extended CID framework is used to compete the HMM-based CID system against a template-based CID system. The …


Predicting The Cost Per Flying Hour For The F-16 Using Programmatic And Operational Variables, Eric M. Hawkes Jun 2005

Predicting The Cost Per Flying Hour For The F-16 Using Programmatic And Operational Variables, Eric M. Hawkes

Theses and Dissertations

This research analyzes operational and programmatic data from all Air National Guard and 13 of 14 active duty F-16C/D Fighter Wings (FW) from 1998 to 2004 in search of explanatory variables that influence a wing's Cost Per Flying Hour (CPFH). Using data from both the Air Force Total Ownership Cost database and from the Air Force Knowledge Systems database, this research evaluates the predictive ability of the following nine explanatory variables: aircraft age, average sortie duration, MajCOM, base location, utilization rate, percent engine type, percent block, percent deployed, and previous year's CPFH, the last four of which were previously untested. …


Modeling And Analysis Of Clandestine Networks, Clinton R. Clark Mar 2005

Modeling And Analysis Of Clandestine Networks, Clinton R. Clark

Theses and Dissertations

Since Sept. 11, 2001, there has been great interest in the military and intelligence communities in using Social Network Analysis (SNA) to support the disruption and destruction of global terrorist networks. SNA results, however, tend to be descriptive and are limited due to the lack of advantageous properties of the relationship measures applied to the arcs in a social network. Further, SNA techniques generally focus on a single network context while real relationships are based in multiple contexts. This thesis develops a new proxy measure of pair-wise potential influence between members of a network, a Holistic Interpersonal Influence Measure (HIIM). …


Optimization Model For Base-Level Delivery Routes And Crew Scheduling, Young-Ho Cha Mar 2005

Optimization Model For Base-Level Delivery Routes And Crew Scheduling, Young-Ho Cha

Theses and Dissertations

In the U.S. Air Force, a Logistic Readiness Squadron (LRS) provides material management, distribution, and oversight of contingency operations. Dispatchers in the LRS must quickly prepare schedules that meet the needs of their customers while dealing with real-world constraints, such as time windows, delivery priorities, and intermittent recurring missions. Currently, LRS vehicle operation elements are faced with a shortage of manpower and lack an efficient scheduling algorithm and tool. The purpose of this research is to enhance the dispatchers' capability to handle flexible situations and produce "good" schedules within current manpower restrictions. In this research, a new scheduling model and …


A Multiple-Case Analysis Of Lean Six Sigma Deployment And Implementation Strategies, Peter M. O'Rourke Mar 2005

A Multiple-Case Analysis Of Lean Six Sigma Deployment And Implementation Strategies, Peter M. O'Rourke

Theses and Dissertations

Lean and Six Sigma are recent developments in continuous improvement methodology that have been popularized by several high-profile companies. The success and complementary nature of these methodologies has led to their combination into a single methodology, commonly called Lean Six Sigma or Lean Sigma. Although there is considerable literature available and many consultants involved with Lean Six Sigma, very little published research addresses the practical experiences of companies that have implemented Lean Six Sigma. The research question for this research is: How and why are certain private sector implementations of Lean Six Sigma successful or unsuccessful? The investigative questions further …