Operational Research Commons^™

Time-Based Collision Risk Modeling For Air Traffic Management, Alan E. Bell

Engineering Management & Systems Engineering Theses & Dissertations

Since the emergence of commercial aviation in the early part of last century, economic forces have driven a steadily increasing demand for air transportation. Increasing density of aircraft operating in a finite volume of airspace is accompanied by a corresponding increase in the risk of collision, and in response to a growing number of incidents and accidents involving collisions between aircraft, governments worldwide have developed air traffic control systems and procedures to mitigate this risk. The objective of any collision risk management system is to project conflicts and provide operators with sufficient opportunity to recognize potential collisions and take necessary …

Multi-Criteria Decision Modeling For Best Value Selections In Target Value Design Integrated Project Delivery, Brent Patrick Griffis

Master's Theses

Integrated Project Delivery (IPD) combined with Target Value Design (TVD) is a better way to deliver value for the client than traditional guaranteed maximum price (GMP) methods. With traditional GMP delivery methods, the interests of the parties are often at odds. The goal of IPD is to align all party interests in order to achieve a win-win scenario. Due to the aligning nature of IPD and the fact that each party’s success is dependent on achieving the project objectives as a whole; a non-biased, transparent, decision-making process is necessary in order to deliver the project objectives within the constraints of …

A Set Union Based Formulation For Course Scheduling And Timetabling, Jesse Paul Bukenberger

Master's Theses

The Course Timetabling Problem is a widely studied optimization problem where a number of sections are scheduled in concert with the assignment of students to sections in order to maximize the desirability of the resulting schedule for all stakeholders. This problem is commonly solved as a linear program with variables for each student or group of students with identical schedules. In this paper we explore an alternative formulation that aggregates binary student variables into integer variables denoting the number of students enrolled in a course. Our solution method assumes decomposition of the general schedule into time blocks, and applies a …

Detailed Inventory Record Inaccuracy Analysis, Hayrettin Kaan Okyay

Graduate Theses and Dissertations

This dissertation performs a methodical analysis to understand the behavior of inventory record inaccuracy (IRI) when it is influenced by demand, supply and lead time uncertainty in both online and offline retail environment separately. Additionally, this study identifies the susceptibility of the inventory systems towards IRI due to conventional perfect data visibility assumptions. Two different alternatives for such methods are presented and analyzed; the IRI resistance and the error control methods. The discussed methods effectively countered various aspects of IRI; the IRI resistance method performs better on stock-out and lost sales, whereas error control method keeps lower inventory. Furthermore, this …

Robust Network Interdiction With Invisible Interdiction Assets, Nail Orkun Baycik

Graduate Theses and Dissertations

We study a version of the shortest path network interdiction problem in which the follower seeks to find the shortest path on a given network and the leader seeks to maximize the follower's shortest path length by interdicting arcs. We consider placement of interdictions that are not visible to the follower; however, we seek to locate interdictions in a manner that is robust against the possibility that some interdiction locations become known to the follower. We formulate the problem as a bi-level program, and use the simulated annealing heuristic to identify high quality solutions. We apply our approach to investigate …

Systems Simulation Analysis Of A Hospital Rapid Response System, Shoruk Mansour

Research and Creative Activities Poster Day

The poster presents a systems simulation analysis of a hospital rapid response system. Analysis of interventions and future work related to the project are included.

Modeling And Analysis Of Patient Care Assistants’ Workflow, Ewing Tiong

Research and Creative Activities Poster Day

Background

While there is a considerable amount of research on medium-to-long decision support models for healthcare systems, little emphasis is placed on research that focuses on short-term operational decisions made by healthcare providers. Patient care assistants (PCAs) provide both indirect and direct patient care under the supervision of a registered nurse (RN). Main responsibilities include:

• Gathering patient data
• Assisting patients with activities of daily living (ADLs)

An Investigation Of Business Transformation Disruptors At The Military Strategic Command Level, Thomas Bock

Engineering Management & Systems Engineering Theses & Dissertations

This dissertation contributes an empirical research on business transformation disruption in the military. Specifically, this exploratory research seeks a better understanding of disruption of business transformation and some of the factors that are likely to impact the transformation process at the military strategic command level. A lack of empirical studies existing in the literature, coupled with the continuous transformation challenges faced by military organizations, make it necessary to conduct this empirical study of business transformation disruption in the military.

This research was carried out utilizing a two-phase mixed-methods approach. The first phase included qualitative data gathering through a series of …

An Investigation Into The Analysis Of Truncated Standard Normal Distributions Using Heuristic Techniques, John Walter Ralls

Engineering Management & Systems Engineering Theses & Dissertations

Standard normal distributions (SND) and truncated standard normal distributions (TSND) have been widely used and accepted methods to characterize the data sets in various engineering disciplines, financial industries, medical fields, management, and other mathematic and scientific applications. For engineering managers, risk managers and quality practitioners, the use of the standard normal distribution and truncated standard normal distribution have particular relevance when bounding data sets, evaluating manufacturing and assembly tolerances, and identifying measures of quality. In particular, truncated standard normal distributions are used in areas such as component assemblies to bound upper and lower process specification limits.

This dissertation presents a …

Assessing Organizational Effectiveness Through The Competing Values Framework A Data Envelopment Approach, Raghavender Macherla

Engineering Management & Systems Engineering Theses & Dissertations

This study proposes a model to diagnose organizations using the mathematical principles of data envelopment analysis (DEA) to the variables generated using competing values framework (CVF) in order to evaluate overall organizational effectiveness. The notion of organizational effectiveness is abstract and difficult to measure due to its complexity and multi-functional nature. Over the years, measurement of organizational effectiveness has remained a challenge due to the lack of agreement on the factors that should be assessed to determine effectiveness. This research is aimed at shedding some light into this topic by using data envelopment analysis as a tool to measure relative …

Antiviral Resistance And Dynamic Treatment And Chemoprophylaxis Of Pandemic Influenza, Sandro Paz

USF Tampa Graduate Theses and Dissertations

Public health data show the tremendous economic and societal impact of pandemic influenza in the past. Currently, the welfare of society is threatened by the lack of planning to ensure an adequate response to a pandemic. This preparation is difficult because the characteristics of the virus that would cause the pandemic are unknown, but primarily because the response requires tools to support decision-making based on scientific methods. The response to the next pandemic influenza will likely include extensive use of antiviral drugs, which will create an unprecedented selective pressure for the emergence of antiviral resistant strains. Nevertheless, the literature has …

Fragment Capture Simulation For Manpads Test Arena Optimization, Michael J. Garee

Theses and Dissertations

The assessment of aircraft survivability against explosive munitions is an expensive undertaking. Test articles for both aircraft and weapon are scarce due to their high costs, leading to a limited supply of test data. The development of newer, hopefully more effective weaponry and protection measures continues despite the short supply of test data. Therefore, test organizations need to explore methods for increasing the quality of test results while looking for ways to decrease the associated costs. This research focuses on the Man-Portable Air-Defense System (MANPADS) as the weapon of choice and live- re arena testing as the experimental data source. …

Enhanced Vehicle Beddown Approximations For The Improved Theater Distribution Model, Jonathan D. White

Theses and Dissertations

Gathering insight into the theater distribution process can be a complex task, especially when estimating potential beddown solutions. Coming up with a low cost feasible mixture of cargo vehicles that will support distribution of military personnel and goods within theater is currently a high priority for force flow analysts at USTRANSCOM. In the past, analysts used a trial and error simulation process that was iterative and time consuming. Recent research has produced the Improved Theater Distribution Model (ITDM), which presents a less time consuming, more precise method to estimate beddown allocations. Improving on this research, two linear programming methods were …

Scheduling And Resource Allocation In Wireless Sensor Networks, Yosef Alayev

Dissertations, Theses, and Capstone Projects

In computer science and telecommunications, wireless sensor networks are an active research area. Each sensor in a wireless sensor network has some pre-defined or on demand tasks such as collecting or disseminating data. Network resources, such as broadcast channels, number of sensors, power, battery life, etc., are limited. Hence, a schedule is required to optimally allocate network resources so as to maximize some profit or minimize some cost. This thesis focuses on scheduling problems in the wireless sensor networks environment. In particular, we study three scheduling problems in the wireless sensor networks: broadcast scheduling, sensor scheduling for area monitoring, and …

Characterizing Forced Communication In Networks, Samuel C. Gutekunst

HMC Senior Theses

This thesis studies a problem that has been proposed as a novel way to disrupt communication networks: the load maximization problem. The load on a member of a network represents the amount of communication that the member is forced to be involved in. By maximizing the load on an important member of the network, we hope to increase that member's visibility and susceptibility to capture. In this thesis we characterize load as a combinatorial property of graphs and expose possible connections between load and spectral graph theory. We specifically describe the load and how it changes in several canonical classes …

Systems Theory As The Foundation For Understanding Systems, Kevin Macg. Adams, Peggy T. Hester, Joseph M. Bradley, Thomas J. Meyers, Charles B. Keating

Engineering Management & Systems Engineering Faculty Publications

As currently used, systems theory is lacking a universally agreed upon definition. The purpose of this paper is to offer a resolution by articulating a formal definition of systems theory. This definition is presented as a unified group of specific propositions which are brought together by way of an axiom set to form a system construct: systems theory. This construct affords systems practitioners and theoreticians with a prescriptive set of axioms by which a system must operate; conversely, any set of entities identified as a system may be characterized by this set of axioms. Given its multidisciplinary theoretical foundation and …

การลดสิ่งแปลกปลอมในกระบวนการสร้างเส้นลายวงจรในโรงงานผลิตแผงวงจรไฟฟ้าชนิดอ่อน, ปิยะนันท์ สยนานนท์

Chulalongkorn University Theses and Dissertations (Chula ETD)

งานวิจัยนี้มีวัตถุประสงค์เพื่อลดปริมาณของเสียที่เกิดจากปัญหาสิ่งแปลกปลอมในกระบวนการสร้างเส้นลายวงจรในโรงงานผลิตแผงวงจรไฟฟ้าชนิดอ่อน โดยการประยุกต์ใช้แนวคิด ซิกซ์ ซิกมา งานวิจัยเริ่มจากการนิยามปัญหาสิ่งแปลกปลอมในกระบวนการสร้างเส้นลายวงจร การวัดเพื่อกำหนดสาเหตุของปัญหาได้เลือกปัจจัยนำเข้าหลักมาพิสูจน์ความมีนัยสำคัญ การวิเคราะห์สาเหตุของปัญหาโดยการประยุกต์ใช้การออกแบบการทดลองเชิงแฟคทอเรียลแบบ 2 ระดับ (2k Factorial Design) เพื่อศึกษาอิทธิพลของปัจจัยที่มีผลต่อการทำให้เกิดของเสีย โดยพบว่ามี 3 ปัจจัยหลักที่เกี่ยวข้องกับของเสียที่เกิดขึ้น คือ ความเข้มของแสง UV ในกระบวนการถ่ายเส้นลายวงจร ความเข้มข้นของสารละลายโซเดียมไฮดรอกไซด์ และอุณหภูมิของสารละลายโซเดียมไฮดรอกไซด์ในกระบวนการลอกลายเส้นลายวงจร ซึ่งเมื่อทําการทดลองเพื่อหาระดับปัจจัย สรุปได้ว่าระดับของปัจจัยที่เหมาะสมในการลดปัญหาสิ่งแปลกปลอม คือ ความเข้มของแสง UV 50 mJ/cm2 ในกระบวนการถ่ายเส้นลายวงจร อุณหภูมิของสารละลายโซเดียมไฮดรอกไซด์ 48°C และ ความเข้มข้นของสารละลายโซเดียมไฮดรอกไซด์ 3.5%wt ในกระบวนการลอกลายเส้นลายวงจร จากนั้นจึงกำหนดแผนการควบคุมตัวแปรต่างๆ โดยจัดทำเป็นมาตรฐานวิธีการปฏิบัติงาน ผลหลังการปรับปรุงพบว่าค่าเฉลี่ยของเสียลดลงจาก 0.27% เหลือเพียง 0.004% โดยการประเมินปริมาณการผลิตคาดว่ามูลค่าความสูญเสียจะลดลงได้ถึง 336,770 บาทต่อเดือน

Positioning Automated Guided Vehicles In A General Guide-Path Layout, Abraham Mendoza, Jose A. Ventura

13th IMHRC Proceedings (Cincinnati, Ohio. USA – 2014)

The locations of dwell points for idle vehicles in an automated guided vehicle (AGV) system determine the response times for pick-up requests and thus affect the performance of automated manufacturing systems. In this study, we address the problem of optimally locating dwell points for multiple AGVs in general guide-path layouts with the objective of minimizing the maximum response time in the system. We propose a mixed integer linear programming (MILP) formulation for the problem. We also develop a generic genetic algorithm (GA) to find near optimal solutions. The MILP model and GA procedure are illustrated using a two-dimensional grid layout …

Integrating Analysis Into A Warehouse Design Workflow, Leon Mcginnis, Timothy Sprock

13th IMHRC Proceedings (Cincinnati, Ohio. USA – 2014)

Supply chain analyses, including those related to material handling systems, are typically purpose-built to answer specific questions and therefore have many different implementations depending on the question, the instance data, and the solver. The purpose-built nature of these models makes it difficult to integrate them into an iterative design workflow. Despite the myriad analysis implementations, the fundamental structure of these systems and their problem domain remains unchanged, suggesting that perhaps analyses could be automatically generated on demand, given an appropriate specification of the particular system to be analyzed. We apply model-based systems engineering (MBSE) methodologies to explore this possibility in …

Throughput Analysis Of S/R Shuttle Systems, Georg Kartnig, Jörg Oser

13th IMHRC Proceedings (Cincinnati, Ohio. USA – 2014)

Shuttle systems are used in high performance automated storage/retrieval unit load systems. Each storage level is serviced by one transfer car travelling in dual command operation. One buffer slot is located at both ends of each level. This decouples horizontal travel from vertical input/output moves, which in this case requires two independent vertical reciprocating lifts at each end of the aisle. Other systems work with only one lift used in lower throughput applications. The content of this paper is treated in the following sections starting with a problem definition and a literature survey. This is followed by a detailed functional …