Other Operations Research, Systems Engineering and Industrial Engineering Commons^™

Preferred Treatment Methods For Patients With Inflammatory Bowel Disease, James L. Deitschel

Theses and Dissertations

Shared decision making is the concept of physicians involving patients in the treatment planning process. The University of Maryland Medical Center is interested in applying shared decision making to the treatment of patients with Inflammatory Bowel Disease (IBD). The two treatment methods analyzed in this study were medical management and surgery. To explore patient preferences between these two alternatives, a discrete choice experiment (DCE) was employed. The responses for the DCE were binary, so logistic regression models were explored. The conditional logistic regression model was determined to be the most appropriate for this analysis. After step-wise regression was performed, a …

An Analysis Of Learning Curve Theory & Diminishing Rates Of Learning, Dakotah W. Hogan

Theses and Dissertations

Traditional learning curve theory assumes a constant learning rate regardless of the number of units produced; however, a collection of theoretical and empirical evidence indicates that learning rates decrease as more units are produced in some cases. These diminishing learning rates cause traditional learning curves to underestimate required resources, potentially resulting in cost overruns. A diminishing learning rate model, Boones Learning Curve (2018), was recently developed to model this phenomenon. This research confirmed that Boones Learning Curve is more accurate in modeling observed learning curves using production data of 169 Department of Defense end-items. However, further empirical analysis revealed deficiencies …

Development Of Cislunar Space Logistics Networks For Satellite Constellation Support Using Event-Driven Generalized Multi-Commodity Network Flows, Alexander R. Collins

Theses and Dissertations

As space becomes an increasingly congested domain, the risk of damage to satellite constellations is increasing. In response, there is an increasing need for capabilities for unmanned repair, refueling, and reconstitution (R3) of those constellations. Cislunar orbits offer a promising storage and low-cost transfer solution for on-orbit service vehicles and replacement satellites to leverage those capabilities. This research makes use of mixed-integer linear programming-based logistics models to determine the situations in which a cislunar mission architecture would offer a cost-effective alternative to Earth-based R3. The network models presented in this research make use of the latest developments in Event-Driven Generalized …

Material Interactions And Self-Assembly In Inkjet Printing, Karam Nashwan Al-Milaji

Theses and Dissertations

Inkjet printing has attracted much attention in recent years as a versatile manufacturing tool, suitable for printing functional materials. This facile, low-cost printing technique with high throughput and accuracy is considered promising for a wide range of applications including but not limited to optical and electronic devices, sensors, solar cells, biochips, and displays. The performance of such functional devices is significantly influenced by the deposit morphology and printing resolution. Therefore, fabrication functional devices with precise footprints by inkjet printing requires deep understanding of ink properties, material interactions, and material self-assembly.

In conventional inkjet printing process, where sessile droplets are directly …

An Analysis Of Major Acquisition Reforms Through Text Mining And Grounded Theory Design, Amanda L. Mcgowin

Theses and Dissertations

Cost growth is an established phenomenon within Defense Acquisition that the US Government has attempted to abolish for decades through seemingly endless cycles of reform. Dozens of experts and senior leaders within the acquisition community have published their notions on the reasons for cost growth, nevertheless, legislation has yet to eradicate this presumed conundrum. For this reason, this research is aimed at identifying existing trends within past major Defense Acquisition Reform legislation, as well as in a compendium of views from leaders within the Defense Acquisition community on the efficacy of acquisition reform, to determine the possible disconnect. To accomplish …

Experimental Designs, Meta-Modeling, And Meta-Learning For Mixed-Factor Systems With Large Decision Spaces, Zachary C. Little

Theses and Dissertations

Many Air Force studies require a design and analysis process that can accommodate for the computational challenges associated with complex systems, simulations, and real-world decisions. For systems with large decision spaces and a mixture of continuous, discrete, and categorical factors, nearly orthogonal-and-balanced (NOAB) designs can be used as efficient, representative subsets of all possible design points for system evaluation, where meta-models are then fitted to act as surrogates to system outputs. The mixed-integer linear programming (MILP) formulations used to construct first-order NOAB designs are extended to solve for low correlation between second-order model terms (i.e., two-way interactions and quadratics). The …

Analyzing The Critical Supply Chain For Unmanned Aircraft Systems, Megan L. Muniz

Theses and Dissertations

Unmanned aerial systems (UAS) play a vital role in present day operations due their asset capability and ability to reduce risk to pilots’ lives. A complex supply chain network capable of producing and integrating all raw materials, components, sub- systems, and systems supports the successful acquisition of a UAS. Such a complex network is supported by vital supply chain decisions. Two important decisions regarding supply chain design include supplier selection and optimal flow of material and product Whether a decision maker wishes to design or interdict a supply chain, the methodology developed in this thesis provides a suite of tailorable …

Feasibility And Environmental Implications Of Using Waste Motor Oil As Alternative Supplemental Fuel In Contingency Prime Power Generation, Zachary S. Bierhaus

Theses and Dissertations

In an era of strict hazardous material restrictions and intense energy savings projects, DoD has an opportunity for a waste-to-energy initiative by looking to vintage diesel engine technology for inspiration. The idea comes in the form of recycled Waste Motor Oil (WMO) which can be used as a fuel in compression-ignition engines. When mixed at a low blend ratio, WMO can supplement diesel fuels to extend the range of fuel stores for electrical power generating equipment at contingency military bases while simultaneously decreasing the burden on fuel supply chain management and the hazardous waste disposal stream. This research looked at …

A Scenario-Based Parametric Analysis Of Stable Marriage Approaches To The Army Officer Assignment Problem, Matthew D. Ferguson

Theses and Dissertations

This paper compares linear programming and stable marriage approaches to the assignment problem under conditions of uncertainty. Robust solutions should exhibit reduced variability in the presence of one or more additional constraints. Several variations of each approach are compared with respect to solution quality, as measured by the overall social welfare among Officers and Assignments, and robustness as measured by the number of changes after a number of randomized perturbations. We examine the contrasts between these methods in the context of assigning Army Officers among a set of identified assignments. Additional constraints are modeled after realistic scenarios faced by Army …

Decomposition Algorithms In Stochastic Integer Programming: Applications And Computations., Babak Saleck Pay

Theses and Dissertations

In this dissertation we focus on two main topics. Under the first topic, we develop a new framework for stochastic network interdiction problem to address ambiguity in the defender risk preferences. The second topic is dedicated to computational studies of two-stage stochastic integer programs. More specifically, we consider two cases. First, we develop some solution methods for two-stage stochastic integer programs with continuous recourse; second, we study some computational strategies for two-stage stochastic integer programs with integer recourse. We study a class of stochastic network interdiction problems where the defender has incomplete (ambiguous) preferences. Specifically, we focus on the shortest …

Optimizing Forecasting Methods For Ustranscom Railcar Demands, James M. Park

Theses and Dissertations

The United States military heavily relies on rail freight operations to meet many of its logistical needs during both peacetime and wartime efforts. As the head organization responsible for managing and overseeing all modes of military transportation, United States Transportation Command depends on timely accurate railcar demand forecasts to drive critical decisions on distribution and placement of railcar assets. However, the intermittent nature of railcar demands based on location and commodity make it a challenging task for forecasters. Furthermore, these “lumpy” demands often come without any obvious trends or seasonality. This study explores the utility of both traditional forecasting methods …

Logistics Simulation For Long Duration Logistics Wargames, Kevin R. Cardenas

Theses and Dissertations

Wargames were originally created to test wartime strategies against opposing forces within a short time frame. Due to the short duration design of these wargames, logistics were deemed irrelevant and it was incorrectly assumed that the warfighter would be logistically supported for the entire duration of the wargame. The purpose of this thesis is to provide insight to the value of capturing logistics within a wargame and to better model the increased requirement for Agile Combat Support. This research utilizes a logistics simulation tool and its outputs to conduct statistical analyses comparing a baseline scenario created to mirror the Joint …

Antecedents Of Fuel Efficiency, James A. Cotton

Theses and Dissertations

Reducing the United States Air Force (USAF)’s fuel use is a major budgetary concern, as the USAF consumes more fuel than the Army, Navy, Marine Corps and all other Department of Defense (DoD) agencies combined. This research focused on fuel efficiency of C-130 Hercules Aircraft Commanders (ACs) by proposing, constructing, and testing a survey measure of behavioral drivers of discretionary pro-environmental professional behaviors among USAF pilots.

Simulation Of Modeling Sortie Generation Process In Turaf, Bahadir Aykiri

Theses and Dissertations

Simulation is a useful technique for engineers and operations researchers. One of the primary advantages of simulation models is that they are able to provide users with practical feedback when analyzing real-world systems. This thesis builds a discrete event simulation of the sortıe generatıon process, to help decision makers in performing analyses regarding quantity of manpower, bottlenecks in supply and maintenance activities; as well as utilization of maintenance manpower, cost and number of sorties produced in a specific time. We only model one aircraft system with four Line Replacement Units (LRU), but any system and its LRUs can be included …

A "Big Bang" Versus A "Small Bang" Approach: A Case Study Of The Expeditionary Combat Support System (Ecss) And The Maintenance, Repair, And Overhaul Initiative (Mroi), George B. Lafiguera

Theses and Dissertations

In 2003, the United States Air Force embarked on one of the largest and most comprehensive logistical transformation to delineate the logistics community’s strategy for supporting the warfighter. A key aspect of this campaign plan was to leverage information technology through an enterprise resource planning (ERP) solution called the Expeditionary Combat Support System (ECSS), a “big-bang” approach. In early 2012, the ECSS program was cancelled mainly due to uncontrollable increases in costs and schedule overruns. In late 2012, the Air Force Sustainment Center (AFSC) launched the Maintenance, Repair, and Overhaul initiative (MROi), a “small-bang” approach, to increase enterprise visibility and …

Using Multiple Objective Decision Analysis To Position Federal Product And Service Codes Within The Kraljic Portfolio Matrix, Robert T. Montgomery

Theses and Dissertations

Despite the best efforts of the Federal Government to implement strategic sourcing, recent Government Accountability Office (GAO) reports highlight major procurement deficiencies and encourage the use of commercial best practices to identify and reap substantial savings. The Kraljic Portfolio Matrix (KPM) is considered the premier tool for purchasing organizations to determine which commercial best practices to utilize for different categories of spend. However, critics of the KPM point to its lack of analytical rigor and the absence of a simplistic quantitative methodology for implementation. The Air Force Installation Contracting Agency (AFICA), the centralized procurement arm for 79 USAF installations worldwide, …

Modeling The Components Of An Economy As A Complex Adaptive System, Richard J. Mickelsen

Theses and Dissertations

Complex systems science is a relatively new discipline and has not been widely applied to the field of economics. Much of current economic theory relies on principles of constrained optimization and often fails to see economic variables as part of an interconnected network. While tools for forecasting economic indicators are based primarily on autoregressive techniques, these techniques are not always well-suited to predicting the future performance of highly volatile data sets such as the stock market. This research portrays the stock market as one component of a networked system of economic variables, with the federal funds rate acting as an …

A Logistic Regression And Markov Chain Model For The Prediction Of Nation-State Violent Conflicts And Transitions, Nicholas Shallcross

Theses and Dissertations

Using open source data, this research formulates and constructs a suite of statistical models that predict future transitions into and out of violent conflict and forecasts the regional and global incidences of violent conflict over a ten-year time horizon. A total of thirty predictor variables are tested and evaluated for inclusion in twelve conditional logistic regression models, which calculate the probability that a nation will transition from its current conflict state, either In Conflict or Not in Conflict, to a new state in the following year. These probabilities are then used to construct a series of nation-specific Markov chain models …

Construction, Analysis, And Data-Driven Augmentation Of Supersaturated Designs, Alex J. Gutman

Theses and Dissertations

Screening designs are used in the early stages of industrial and computer experiments to find the most important input factors affecting a system's output. They provide an economical way to remove unimportant factors from further, potentially costly, experimentation. However, when an experiment has a large number of control factors and limited number of available runs, it is infeasible to run a traditional screening design. In these situations, experimenters can use supersaturated designs. A supersaturated design is a fractional factorial design that can screen a set of k factors in n runs, where k is greater than n -1. Unfortunately, they …

Space Debris Mitigation Conops Development, Earl B. Alejandro

Theses and Dissertations

Space debris remains an unsolved hazard for space operators and astronomers alike. Passive debris mitigation techniques have been enumerated and codified by the UNCOPUOS and IADC and several proposals for actively mitigating space debris have been presented. However, the space debris problem requires reframing. On the way to developing a viable CONOPS, a multi-disciplinary construct for building solution sets to tackle the space debris problem must be created. It must be shaped by building blocks of active and passive debris mitigation techniques, debris characterization and law. Central considerations must be taken. First, targeting of space debris for removal must be …

Urgent Aeromedical Evacuation Network Capacity Planning, Scott C. Finkbeiner

Theses and Dissertations

Aeromedical Evacuation (AE) has been steadily utilized during Operation Iraqi Freedom and Operation Enduring Freedom. AE is a global enterprise. The current structure of AE is facing changes as forces scale down from operations in Iraq and Afghanistan. AE will, however, continue to be important in its domestic use in the continental USA (CONUS). Current practice is to pull aircraft (e.g. C-17, C-130 or KC-135) from their normal operations to meet Urgent and Priority patient needs when local alternatives are infeasible. An alternative to the current system would be having a centralized "bed-down" location for AE operations that would house …

A Mixed Integer Programming Model For Improving Theater Distribution Force Flow Analysis, Micah J. Hafich

Theses and Dissertations

Obtaining insight into potential vehicle mixtures that will support theater distribution, the final leg of military distribution, can be a challenging and time consuming process for United States Transportation Command (USTRANSCOM) force flow analysts. The current process of testing numerous different vehicle mixtures until separate simulation tools demonstrate feasibility is iterative and overly burdensome. Improving on existing research, a mixed integer programming model was developed to allocate specific vehicle types to delivery items, or requirements, in a manner that would minimize both operational costs and late deliveries. This gives insight into the types and amounts of vehicles necessary for feasible …

Operational Planning Of Channel Airlift Missions Using Forecasted Demand, Taylor J. Leonard

Theses and Dissertations

Past research proposed that it is possible to forecast cargo demand using time series models and that there exists potential cost savings in the way that Civilian Reserve Air Fleet (CRAF) is used for cargo airlift. United States Transportation Command (USTRANSCOM) performs annual fixed-buys of CRAF to support airlift needs. Forecasted cargo demand would allow for reasonably accurate cargo projections vs. the current expected value estimation. Accurate forecasting allows for greater fixed-buys, further incentivizing CRAF airlines as well as reducing the number of additional aircraft purchases during the quarterly and monthly buys. Multiple forecasting models are constructed and the results …

The Moderating Effect Of Network Centrality On The Relationship Between Work Experience Variables And Organizational Commitment, Luke M. Kaspari

Theses and Dissertations

The purpose of this research was to identify the effect of an individual's network position on the relationship between work experience variables and affective commitment. This study tested three hypotheses, which were introduced through a comprehensive literature review, regarding the relationships between work experience variables and affective commitment. Research has indicated linkages between social network centrality and organizational commitment; however, the specific effects of centrality remain unclear. Therefore, this research developed and tested a moderation model to identify relationships between network centrality, affective commitment, and three work experience variables: psychological empowerment (PE), leader-member exchange (LMX), and perceived organizational support (POS). …

Effective Measurement Of Reliability Of Repairable Usaf Systems, Louis J. Hogge

Theses and Dissertations

The USAF generally does not know the reliability of its fielded repairable systems. The reported metric, Mean Time Between Failure (MTBF), is too lagging to be actionable in the best case, and is not representative of actual system reliability in the worst case. This thesis investigates the statistical techniques for measurement and analysis of the reliability of fielded repairable systems, which are very different than nonrepairables. To frame the investigation, a comparison is made between the generally accepted definitions and metrics and those used across the US Air Force (USAF). Reliability can be analyzed in four context areas: reliability prediction …

A Prototype Overview For Allocating Usaid Foreign Aid, Deane E. Cover

Theses and Dissertations

The United States Agency for International Development (USAID) is the federal government agency primarily responsible for administering civilian foreign aid. In fiscal year 2011, USAID spent approximately $15 billion in an effort to assist countries recovering from disaster, trying to escape poverty, and engaging in democratic reforms. Using Value-Focused Thinking, regression, and optimization techniques, this thesis utilizes overarching USAID objectives and underlying policy to develop a prototype overview model that is used to provide insight to a Decision Maker regarding how changes in funding allocation can lead to improved impact.

A Simulation To Evaluate Joint Military Logistics In A Humanitarian Assistance Environment, Ryan S. Fisher

Theses and Dissertations

Currently, no capability exists to cost-effectively simulate and measure a Joint Task Force-Port Opening (JTF-PO) operation to predict cargo throughput based on the availability of resources. The purpose of this research is to create a decision model using Arena® simulation software to provide United States Transportation Command (USTRANSCOM) decision makers the ability to predict cargo throughput in a Humanitarian Assistance/Disaster Response (HA/DR) scenario. The data used in this simulation were taken from the JTF-PO involvement in Operation UNIFIED RESPONSE, Port-au-Prince, Haiti 2010. The research uses a design of experiments approach to statistically plan and measure the throughput of cargo based …

Automatic Target Recognition For Hyperspectral Imagery, Kelly D. Friesen

Theses and Dissertations

Automatic target detection and recognition in hyperspectral imagery offer passive means to detect and identify anomalies based on their material composition. In many combat identification approaches through pattern recognition, a minimum level of confidence is expected with costs associated with labeling anomalies as targets, non-targets or out-of-library. This research approaches the problem by developing a baseline, autonomous four step automatic target recognition (ATR) process: 1) anomaly detection, 2) spectral matching, 3) out-of-library decision, and 4) non-declaration decision. Atmospheric compensation techniques are employed in the initial steps to compare truth library signatures and sensor processed signatures. ATR performance is assessed and …

Understanding The Instruments Of National Power Through A System Of Differential Equations In A Counterinsurgency, Cade M. Saie

Theses and Dissertations

Models that account for the progression of nation-building and the impacts of the instruments of national power -- Diplomacy, Informational, Military, and Economic effects -- are rare. This research proposes the development of such a model. Through the derivation of state indices for the operational variables of Political, Military, Economic, Social, Infrastructure, and Information, a functional form of a system of differential equations is developed to account for the interactions between the state indices and instruments of national power. This methodology is a mean-field inverse problem which solves for the coefficients of the differential equations in a data-driven manner. Publicly …

Combat Identification Of Synthetic Aperture Radar Images Using Contextual Features And Bayesian Belief Networks, John X. Situ

Theses and Dissertations

Given the nearly infinite combination of modifications and configurations for weapon systems, no two targets are ever exactly the same. Synthetic Aperture Radar (SAR) imagery and associated High Range Resolution (HRR) profiles of the same target will have different signatures when viewed from different angles. To overcome this challenge, data from a wide range of aspect and depression angles must be used to train pattern recognition algorithms. Alternatively, features invariant to aspect and depression angle must be found. This research uses simple segmentation algorithms and multivariate analysis methods to extract contextual features from SAR imagery. These features used in conjunction …