Operations Research, Systems Engineering and Industrial Engineering Commons^™

Reliability Analysis Of Social Networks, Kellie R. Schneider

Graduate Theses and Dissertations

The primary focus of this dissertation is on the quantification of actor interaction and the dissemination of information through Social networks. Social networks have long been used to model the interactions between people in various Social and professional contexts. These networks allow for the explicit modeling of the complex interrelations between relevant individuals within an organization and the role they play in the decision making process. This dissertation considers Social networks represented as network flow models in which actors have the ability to provide some level of influence over other actors within the network. The models developed incorporate performance metrics …

Surveillance Planning Against Smart Insurgents In Complex Terrain, Nabil Lehlou

Graduate Theses and Dissertations

This study is concerned with finding a way to solve a surveillance system allocation problem based on the need to consider intelligent insurgency that takes place in a complex geographical environment. Although this effort can be generalized to other situations, it is particularly geared towards protecting military outposts in foreign lands. The technological assets that are assumed available include stare-devices, such as tower-cameras and aerostats, as well as manned and unmanned aerial systems. Since acquiring these assets depends on the ability to control and monitor them on the target terrain, their operations on the geo-location of interest ought to be …

Load Mixing To Improve Container Utilization, Crystal Wilson

Graduate Theses and Dissertations

The under utilization in trucking leads to nearly 5 billion gallons of wasted fuel annually. One way to recapture part of this waste is to use collaborative logistics. This research focuses on one specific aspect of collaborative logistics: load mixing. Load mixing is the idea of mixing two or more items of different weights in the same container to reduce the number of trucks needed.

Load mixing is similar to other packing problems such as the knapsack and container loading problems. However, traditional packing problems typically only assume a single type of capacity (e.g., weight), whereas load mixing must simultaneously …

High Speed Turning Of Compacted Graphite Iron (Cgi) Using Controlled Modulation, Tyler Paul Stalbaum

Open Access Theses

Compacted graphite iron (CGI) is a material which emerged as a candidate material to replace cast iron (CI) in the automotive industry for engine block castings. Its thermal and mechanical properties allow the CGI-based engines to operate at higher cylinder pressures and temperatures than CI-based engines, allowing for lower fuel emissions and increased fuel economy. However, these same properties together with the thermomechanical wear mode in the CGI-CBN system result in poor machinability and inhibit CGI from seeing wide spread use in the automotive industry.

In industry, machining of CGI is done only at low speeds, less than V = …

Scheduling In Mohs Micrographic Surgery Clinics, Stephen Vincent Steidle

Open Access Theses

Mohs Micrographic Surgery (MMS) is a surgical method used for the excision of aggressive skin cancers in areas of high cosmetic importance, such as the face and hands. The practice has been gaining popularity worldwide for its low recurrence rates and cosmetic results. Current clinics though are plagued by extreme wait times and an overall poor patient experience. In this paper we look to explore this problem by applying systems engineering principles including optimization and scheduling with the goal of improving the patient experience. Currently, little literature exists exploring the difficulties associated with scheduling for MMS clinic which primarily revolve …

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 …

Modeling The Adoption Of Identification Standards Within The Healthcare Supply Chain, Angelica Burbano

Graduate Theses and Dissertations

The adoption of identification standards and its associated technology in the healthcare supply chain has been slow over the past twenty five years, despite the evidence of the benefits that can be achieved. The widespread use of identification standards in the form of barcode labeled medical products can contribute to the reduction of point of care errors and can increase the efficiency of healthcare supply chain related processes. This research is focused on the analysis of the adoption of identification standards in the healthcare supply chain with a particular focus on the healthcare provider adoption challenges. The research is divided …

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 …

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 …

Patient And Nurse Considerations In Home Health Routing With Remote Monitoring Devices, Jessica Spicer

Graduate Theses and Dissertations

We build on the current consistent vehicle routing problem literature by formulating a novel multi- objective mathematical model of the home health scheduling and routing problem that includes the option of assigning some patient visits to remote monitoring devices, with the objectives of mini- mizing total cost, achieving nurse consistency and creating balanced nurse workloads. A heuristic solution approach that approximates the efficient frontier of this multiobjective problem is pre- sented and validated, and the results of using this methodology to solve several realistic instances are included. We also analyze the assignment of patients to devices and present some managerial …

Adaptive Intensity Modulated Radiation Therapy Planning Optimization With Changing Tumor Geometry And Biology Enforcing Both Cumulative And Fraction Size Dose Constraints, Behlul Saka

Graduate Theses and Dissertations

Intensity Modulated Radiation Therapy (IMRT) is a modern technique of delivering radiation treatments to cancer patients. In IMRT technology, intensities must be chosen for the many small unit grids into which the beams are divided to produce a desired distribution of dose at points throughout the body with the goal of maximizing dose delivered to the tumor while sparing healthy tissues from excessive radiation and keeping dose homogeneous across the tumor. Although IMRT plans are optimized as a single overall treatment plan, they are delivered over 30-50 treatment sessions (fractions) and both cumulative and per-fraction dose constraints apply. The extended …

Improvements On Just-About-Right (Jar) Scales As Product Optimization Tools Using Kano Modeling Concepts, Bangde Li

Graduate Theses and Dissertations

Attribute Kano characteristics are useful in product design to prioritize development efforts. However, attribute Kano characteristics have not been discussed and applied to product optimization when using Just-About-Right (JAR) scales. Product optimizations without identifying attributes Kano characteristics can be misleading. The two objectives in this research were: 1. Determine attribute Kano categories using a modified classic Kano classification methodology. 2. Propose a method to measure attribute performance and identify attribute Kano characteristics to direct product optimization. Two methodologies of attribute Kano classification were investigated. In experiment one, a modified classic Kano methodology was employed to determine attribute Kano categories through …

Inventory Models For Intermittent Highly Variable Demand And Policy Parameter Adjustments To Meet Desired Service Level Requirements, Yasin Unlu

Graduate Theses and Dissertations

This dissertation consists of three assays. The first assay examines the robustness of lead time demand models for the continuous review (r;Q) inventory policy. A number of classic distributions as well as distribution selection rules are examined under a wide variety of demand conditions. First, the models are compared to each other by assuming a known demand process and evaluating the errors associated with using a different model. Then, the models are examined using a large sample of simulated demand conditions. Approximation results of inventory performance measures - ready, rate excepted number of backorders and on-hand inventory levels are reported. …

Integrated Planning For Rural Rail Transportation, Jeffrey Cohan Gwaltney

Graduate Theses and Dissertations

Population growth in rural areas has led to new interest in rail transportation. Planning a passenger rail system involves numerous difficult decisions, most representing a trade-off between customer service and cost. In this work, we attempt to integrate many of these planning decisions. We consider strategic decisions such as station location and vehicle procurement, as well as tactical issues that include vehicle scheduling. Our integrated model exploits the linear network structure that best suits many rural American communities, including Northwest Arkansas. Due to the intractability of the integrated rail planning problem, we have developed a customized heuristic approach to solve …

Using Discrete Event Computer Simulation To Analyze The Effects Of Proposed Changes To Personnel In A Hospital Medical Laboratory, Gerardo Morales

Theses and Dissertations - UTB/UTPA

A discrete event computer simulation is used to model a portion of the medical laboratory at Doctors Hospital at Renaissance in order to assess the current situation as well as to review the planed personnel changes. The area under observation is the section in which the processor(s) receive, label and distribute the patient samples. There are four cases modeled in the simulation: The main focus is to determine if one or two processors are needed per shift and if the high level of phone calls poses a significant delay to the processors’ workflow. The simulation results indicate that having two …

An Empirical Investigation Of Supply Chain Excellence In Healthcare, Brian Keith Smith

Graduate Theses and Dissertations

This research is motivated by opportunities to improve the cost and quality of healthcare delivery through improved supply chain processes. This research assesses the quality of the healthcare supply chain and identifies factors that are driving supply chain excellence among organizations in the healthcare industry. The first objective of this research is to assess the state of quality measurement in the healthcare supply chain. The achievement of this first objective is presented in Chapter 3 of this dissertation in the form of a manuscript accepted for publication in The Quality Management Journal. The second research objective is to develop …

An Analysis Of Sustained Collaborative Research Activities Between University Organized Research Units And Industry: A Case Study Of Three Institutions, Elizabeth Taraski Mcdonnell

Seton Hall University Dissertations and Theses (ETDs)

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