Operational Research Commons^™

On The Maintenance Modeling And Optimization Of Repairable Systems: Two Different Scenarios, Suzan Alaswad

Graduate Theses and Dissertations

The use of mathematical modeling for the purpose of analyzing and optimizing the performance of repairable systems is widely studied in the literature. In this dissertation, we study two different scenarios on the maintenance modeling and optimization of repairable systems. First, we study the long-run availability of a traditional repairable system that is subjected to imperfect corrective maintenance. We use Kijima's second virtual age model to describe the imperfect repair process. Because of the complexity of the underlying probability models, we use simulation modeling to estimate availability performance and meta-modeling to convert the reliability and maintainability parameters of the repairable …

Capacity Planning For Elderly Care In Ireland Using Simulation Modeling, Mohamed Ragab, Waleed Abo Hamad, Amr Arisha

Conference papers

Global population aging is creating an immense pressure on healthcare facilities making them unable to cope with the growing demand for elderly healthcare services. Current demand-supply gaps result in prolonged waiting times for patients and substantial cost burdens for healthcare systems due to delayed discharges. This paper describes a project aimed at presenting modeling and simulation to address elderly care pathways within the Irish healthcare sector. The management of frail patients admitted to acute hospitals and the introduction of the new intermediate care beds are alternative interventions that healthcare executives are interested in simulating to examine their impact on the …

The Factors Behind A Successful Implementation Of Electronic Health Records Systems, Anjee Gorkhali

Engineering Management & Systems Engineering Theses & Dissertations

This research explores the role that budget for Information System (IS) and technical expertise of healthcare service provider staff play on the successful leap from a partial to exhaustive implementation of Electronic Health Records (EHR) Systems. Technical expertise in Information Systems might not be easily measurable directly, but there are a number of indicators that could be used as a proxy, such as: Information System (IS) Department Budget, number of IS staff and the extent of technical trainings provided by the IS department to the clinical staff. This research study hypothesizes that quality technical trainings conducted by an IS department …

Minimization Of Collateral Damage In Airdrops And Airstrikes, Steven P. Dillenburger

Theses and Dissertations

Collateral damage presents a significant risk during air drops and airstrikes, risking citizens' lives and property, straining the relationship between the United States Air Force and host nations. This dissertation presents a methodology to determine the optimal location for making supply airdrops in order to minimize collateral damage while maintaining a high likelihood of successful recovery. A series of non-linear optimization algorithms is presented along with their relative success in finding the optimal location in the airdrop problem. Additionally, we present a quick algorithm for accurately creating the Pareto frontier in the multi-objective airstrike problem. We demonstrate the effect of …

The Multiobjective Average Network Flow Problem: Formulations, Algorithms, Heuristics, And Complexity, Jeremy D. Jordan

Theses and Dissertations

Integrating value focused thinking with the shortest path problem results in a unique formulation called the multiobjective average shortest path problem. We prove this is NP-complete for general graphs. For directed acyclic graphs, an efficient algorithm and even faster heuristic are proposed. While the worst case error of the heuristic is proven unbounded, its average performance on random graphs is within 3% of the optimal solution. Additionally, a special case of the more general biobjective average shortest path problem is given, allowing tradeoffs between decreases in arc set cardinality and increases in multiobjective value; the algorithm to solve the average …

Design And Implementation Of Erp Software In Material Supply Chain Management For Siix Corp., Xing'er Chen

World Maritime University Dissertations

No abstract provided.

Rough-Cut Capacity Planning In Multimodal Freight Transportation Networks, Robert B. Hartlage

Theses and Dissertations

A main challenge in transporting cargo for United States Transportation Command (USTRANSCOM) is in mode selection or integration. Demand for cargo is time sensitive and must be fulfilled by an established due date. Since these due dates are often inflexible, commercial carriers are used at an enormous expense, in order to fill the gap in organic transportation asset capacity. This dissertation develops a new methodology for transportation capacity assignment to routes based on the Resource Constrained Shortest Path Problem (RCSP). Routes can be single or multimodal depending on the characteristics of the network, delivery timeline, modal capacities, and costs. The …

Freight Forecasting Of Dry Bulk Market Based On The Bp Neural Network, Qianran Huang

World Maritime University Dissertations

No abstract provided.

Study On Optimal Dwell Time At Jakarta International Container Terminal, Siti Nurrochmah Badrudin

World Maritime University Dissertations

No abstract provided.

Container-Handling Operation Optimization At Koja Container Terminal, Moh Taufik Hidayat

World Maritime University Dissertations

No abstract provided.

The Rationality Study On Capacity Allocation For Cscl’S Asia-Europe Route, Yan Zhou

World Maritime University Dissertations

No abstract provided.

Extendsim-Based Research On Transport Process Optimization Of Emergency Cold-Chain Logistics, Ran Zhang

World Maritime University Dissertations

No abstract provided.

The In-Transit Vigilant Covering Tour Problem Of Routing Unmanned Ground Vehicles, Huang Teng Tan

Theses and Dissertations

The routing of unmanned ground vehicles for the surveillance and protection of key installations is modeled as a new variant of the Covering Tour Problem (CTP). The CTP structure provides both the routing and target sensing components of the installation protection problem. Our variant is called the in-transit Vigilant Covering Tour Problem (VCTP) and considers not only the vertex cover but also the additional edge coverage capability of the unmanned ground vehicle while sensing in-transit between vertices. The VCTP is formulated as a Traveling Salesman Problem (TSP) with a dual set covering structure involving vertices and edges. An empirical study …

A Model For Optimizing The Allocation Of Ethanol Production In The U.S., Anali Huggins

Department of Industrial and Management Systems Engineering: Dissertations, Theses, and Student Research

In the last five years, fuel prices have fluctuated from 2.86$/gallon to 3.87$/gallon which represents an increase of 35%. This situation has collocated the ethanol manufacturing in an advantageous situation. However, a major problem that is faced by the ethanol producers is the high cost of transportation. The objective of this thesis study is to determine the optimal allocation of ethanol production in the U.S. in 2009 that minimizes the transportation cost. This thesis is based on the application of a linear programing model. The thesis is focused on two questions. The first is the optimal allocation of ethanol between …

Optimization Models And Algorithms For Truckload Relay Network Design, Hector Andres Vergara Arteaga

Graduate Theses and Dissertations

Driver turnover is a significant problem for full truckload (TL) carriers that operate using point-to-point (PtP) dispatching. The low quality of life of drivers due to the long periods of time they spend away from home is usually identified as one of the main reasons for the high turnover. In contrast, driver turnover is not as significant for less-than-truckload (LTL) carriers that use hub-and-spoke transportation networks which allow drivers to return home more frequently. Based on the differences between TL and LTL, the use of a relay network (RN) has been proposed as an alternative dispatching method for TL transportation …

Locating And Protecting Facilities Subject To Random Disruptions And Attacks, Hugh Medal

Graduate Theses and Dissertations

Recent events such as the 2011 Tohoku earthquake and tsunami in Japan have revealed the vulnerability of networks such as supply chains to disruptive events. In particular, it has become apparent that the failure of a few elements of an infrastructure system can cause a system-wide disruption. Thus, it is important to learn more about which elements of infrastructure systems are most critical and how to protect an infrastructure system from the effects of a disruption. This dissertation seeks to enhance the understanding of how to design and protect networked infrastructure systems from disruptions by developing new mathematical models and …

Generating Minimal T-Wise Test Suites, Luis C. Gutierrez, Carlos Nieto, Francisco Zapata, Martine Ceberio

COURI Symposium Abstracts, Summer 2012

As the use of computing devices increases every day, users rely on the adequate functioning of software. When software is not tested properly, it can yield erroneous information or a complete failure of the system. The NIST estimates that defective software cost the United States economy close to $60 billion a year. Therefore, there is a need to develop software testing techniques that are time and cost effective. Fully testing software under all possible combinations of parameters values cannot be reduced. However, testing can focus on covering all combinations of subsets of parameters and empirical data shows that doing so …

Meta-Heuristics Analysis For Technologically Complex Programs: Understanding The Impact Of Total Constraints For Schedule, Quality And Cost, Henry Darrel Webb

EMSE Doctoral Projects

Program management data associated with a technically complex radio frequency electronics base communication system has been collected and analyzed to identify heuristics which may be utilized in addition to existing processes and procedures to provide indicators that a program is trending to failure. Analysis of the collected data includes detailed schedule analysis, detailed earned value management analysis and defect analysis within the framework of a Firm Fixed Price (FFP) incentive fee contract.

This project develops heuristics and provides recommendations for analysis of complex project management efforts such as those discussed herein. The analysis of the effects of the constraints on …

Identifying Operations Research Systems Analysts' Technical Competencies: A Delphi Approach, William T. Winklbauer

Engineering Management & Systems Engineering Theses & Dissertations

After the attacks of September 11, 2011, the demands for more agile, adaptive, critical-thinking, and multi-talented U.S. Army Operations Research Systems Analysts (FA49s) have only increased. Tomorrow's joint operating environment demands U.S. Army FA49s to be ingenious, proactive, and multi-talented; proficient in their core competencies as military leaders as well as being proficient in their technical competencies as problem solvers in the operations research field.

The purpose of this study was to identify the technical competencies and knowledge, skills, and abilities (KSAs) required for future U.S. Army FA49s to perform their duties within the joint operating environment of the next …

Establishing Relationships Between Risk Management And Knowledge Transfer, Garrett S. Haltiwanger

Engineering Management & Systems Engineering Theses & Dissertations

Risk management (RM) and Knowledge management (KM) have mostly been treated as separate management philosophies. Risk management is a widely taught topic in academia and is practiced in industry. Knowledge management is being taught at increasingly more colleges and many companies are discovering a need for managing knowledge. This dissertation shows that some research has been conducted to apply the principles of knowledge management in establishing risk management plans. To a lesser extent there has been research conducted to apply the philosophies of risk management to identifying knowledge gaps and maintaining corporate knowledge. Both risk management and knowledge management are …

Incorporating Memory And Learning Mechanisms Into Meta-Raps, Arif Arin

Engineering Management & Systems Engineering Theses & Dissertations

Due to the rapid increase of dimensions and complexity of real life problems, it has become more difficult to find optimal solutions using only exact mathematical methods. The need to find near-optimal solutions in an acceptable amount of time is a challenge when developing more sophisticated approaches. A proper answer to this challenge can be through the implementation of metaheuristic approaches. However, a more powerful answer might be reached by incorporating intelligence into metaheuristics.

Meta-RaPS (Metaheuristic for Randomized Priority Search) is a metaheuristic that creates high quality solutions for discrete optimization problems. It is proposed that incorporating memory and learning …

Simulation Modeling And Analysis Of The Impact Of Individual Mobility Augmentee Loss At The Tanker Airlift Control Center, Megan A. Leiter

Theses and Dissertations

The Tanker Airlift Control Center (TACC) operates as the execution arm for Air Mobility Command's Global Reach mission. The Command and Control Directorate (XOC) monitors the execution of missions tasked to the 18th Air Force. Approximately 70% of the personnel on the operations floor are considered Individual Mobility Augmentees (IMA). Adjustments in manpower, specifically the loss of IMAs, at the TACC/XOCG may impact their responsiveness to mission deviations. This research develops a discrete event simulation using a combination of SME and historical data to capture the activities of a section of the personnel on the operations floor and the potential …

A Quantitative Methodology For Vetting "Dark Network" Intelligence Sources For Social Network Analysis, James F. Morris

Theses and Dissertations

Social network analysis (SNA) is used by the DoD to describe and analyze social networks, leading to recommendations for operational decisions. However, social network models are constructed from various information sources of indeterminate reliability. Inclusion of unreliable information can lead to incorrect models resulting in flawed analysis and decisions. This research develops a methodology to assist the analyst by quantitatively identifying and categorizing information sources so that determinations on including or excluding provided data can be made. This research pursued three main thrusts. It consolidated binary similarity measures to determine social network information sources' concordance and developed a methodology to …

Developing And Assessing Leadership In Engineering Students, W. Vincent Wilding, Thomas A. Knotts, William G. Pitt, Morris D. Argyle

Faculty Publications

Developing and Assessing Leadership in Engineering Students W. Vincent Wilding, Thomas A. Knotts IV, William G. Pitt, and Morris D. Argyle Department of Chemical Engineering, Brigham Young University The Ira A. Fulton College of Engineering and Technology at Brigham Young University is focusing on five initiatives: Leadership, Innovation, Global Awareness, Character, Technical Excellence. Efforts in the realm of leadership include freshmen leadership seminars and a required sophomore course entitled Global Leadership in a Technological World. Departments within the college are expected to build on this foundation in the junior and senior years. The Chemical Engineering Department has developed an effective …

Development And Validation Of A Model For Granular Material Volume Measurements, Pourya Fasounaki

Department of Industrial and Management Systems Engineering: Dissertations, Theses, and Student Research

Keeping inventory record of packed grains in silos poses challenges since the bulk material’s different segments do not discharge uniformly, leading to formation of random peaks and valleys on the surface. To facilitate obtaining accurate volume measurement of the grains by taking into account this non-linear behavior on the surface, laser or plumb-bob level-sensing devices are employed at different part of the surface to probe the level of material under those regions.

The main goals of this research is to study the behavior of granular material in silo while discharging downward and by doing so, differentiate certain flow patterns formed …

Extensions Of Multistage Stochastic Optimization With Applications In Energy And Healthcare, Ludwig Charlemagne Kuznia

USF Tampa Graduate Theses and Dissertations

This dissertation focuses on extending solution methods in the area of stochastic optimization. Attention is focused to three specific problems in the field. First, a solution method for mixed integer programs subject to chance constraints is discussed. This class of problems serves as an effective modeling framework for a wide variety of applied problems. Unfortunately, chance constrained mixed integer programs tend to be very challenging to solve. Thus, the aim of this work is to address some of these challenges by exploiting the structure of the deterministic reformulation for the problem. Second, a stochastic program for integrating renewable energy sources …

Generating Minimal Pair-Wise Covering Test Suites, Luis C. Gutierrez ^, Martine Ceberio *

COURI Symposium Abstracts, Spring 2012

Software is ubiquitous and needs to be reliable. Software testing therefore plays an important role in software development. Proper testing a software system informs about its quality and reliability so as to prevent unexpected behavior during system execution. One of the methods to prevent failures consists in testing a system under different input values, but when all possible input values are tested, an impractical number of test cases might result. In software testing, pair-wise testing is a combinatorial technique which uses combination of pair input values to generate test cases. Using pair-wise testing dramatically reduces the number of test cases, …

Risk Quadruplet: Integrating Assessments Of Threat, Vulnerability, Consequence, And Perception For Homeland Security And Homeland Defense, Kara Norman Hill

Engineering Management & Systems Engineering Theses & Dissertations

Risk for homeland security and homeland defense is often considered to be a function of threat, vulnerability, and consequence. But what is that function? And are we defining and measuring these terms consistently? Threat, vulnerability, and consequence assessments are conducted, often separately, and data from one assessment could be drastically different from that of another due to inconsistent definitions of terms and measurements, differing data collection methods, or varying data sources. It has also long been a challenge to integrate these three disparate assessments to establish an overall picture of risk to a given asset. Further, many agencies conduct these …

A Discrete Event Simulation Of Network Centric Operations: Modeling Unbalanced Combat Configurations In Symmetric Engagements, Mahmoud Turki Khasawneh

Engineering Management & Systems Engineering Theses & Dissertations

Network Centric Operations (NCO) has been dubbed the most significant revolution in military affairs (RMA) in the past 200 years. The promise of NCO is based on the notion that information sharing and connectivity is fundamental to the effectiveness of a combat force. This due to the ability of a properly networked force to self-synchronize itself as it engages enemy forces. The purposeful arrangement of assets in a combat force is what makes it 'properly networked'. What is a purposeful arrangement of combat assets? How should a force organize to enhance information sharing and connectivity? And how does connectivity within …

The Effectiveness Of Using Diversity For Selecting Multiple Classifier Systems, Harris K. Butler

Theses and Dissertations

A wealth of approaches exists to perform classification of items of interest. The goal of fusion techniques is to exploit complementary approaches and merge the information provided by these methods to provide a solution superior than any single method. Associated with choosing a fusion algorithm is the choice of algorithm or algorithms that will be fused. This decision is most often referred to as ensemble selection. Historically classifier ensemble accuracy has been used to accomplish this task. More recently research has focused on creating and evaluating diversity metrics to more effectively select ensemble members. This research focuses on the use …