Operational Research Commons^™

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 …

Using Vft As A Constraint For Goal Programming Models: A Case Study For Turkish Air Force Flying Hour Program, Ahmet Bengoz

Theses and Dissertations

In its 60-year history, there have been many published documents in the literature about goal programming (GP), but contributions to the literature are still needed. This research intends to add to the literature on goal-programming models by discussing one of the key assumptions of GP regarding linearity, and by discussing some of the issues regarding incommensurability (difference in data types) and weighting. GP requires an interaction between the decision maker (DM) and the analyst to ensure that the model reflects the DM's preferences. However, it may be difficult for them to interact if the mathematical model is very large and …

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 …

Surveillance Versus Reconnaissance: An Entropy Based Model, Tamilyn S. Dismukes

Theses and Dissertations

With the advancing capabilities of Intelligence, Surveillance, and Reconnaissance (ISR) assets and sensors, effective utilization of these resources continues to pose a challenge to military decision makers. The methodology developed explores allocation of ISR assets while balancing detection of new targets versus surveillance of already detected targets using entropy as a Measure of Effectiveness (MOE). Scenarios with an unknown number of static and moving targets in a bounded geographical region are considered. A baseline model was built to examine four different search algorithms: random, raster, greedy, and a rollout algorithm based on dynamic programming. A space-filling Nearly Orthogonal Latin Hypercube …

A Decision Analysis Perspective On Multiple Response Robust Optimization, Jonathan S. Findley

Theses and Dissertations

Decisions in which multiple objectives must be optimized simultaneously occur frequently in government, military, and industrial settings. One method a decision maker may use to assist in such decisions is the application of a desirability function. An informed specification of the desirability function's parameters is essential to accurately describe the decision maker's value trade-offs and risk preference. This thesis uses utility transversality to analyze the implicit trade-off and risk attitude assumptions attendant to the desirability function. The desirability function does not explicitly account for response variability. A robust solution takes not only the expected response into account, but also its …

Using Hybrid Simulation/Analytical Queueing Networks To Capacitate Usaf Air Mobility Command Passenger Terminals, Meredithe A. Jessup Ii

Theses and Dissertations

The objective of this study is to model operations at an airport passenger terminal to determine the optimal service capacities at each station given estimated passenger flow patterns and service rates. The central formulation is an open Jackson queueing network that can be applied to any USAF Air Mobility Command (AMC) terminal regardless of passenger type mix and flow data. A complete methodology for analyzing passenger flows and queue performance of a single flight is produced and then embedded in a framework to analyze the same for multiple departing flights. Queueing network analysis (QNA) is used because no special software …

Modeling Small Unmanned Aerial System Mishaps Using Logistics Regression And Artificial Neural Networks, Sean E. Wolf

Theses and Dissertations

A dataset of 854 small unmanned aerial system (SUAS) flight experiments from 2005-2009 is analyzed to determine significant factors that contribute to mishaps. The data from 29 airframes of different designs and technology readiness levels were aggregated. 20 measured parameters from each flight experiment are investigated, including wind speed, pilot experience, number of prior flights, pilot currency, etc. Outcomes of failures (loss of flight data) and damage (injury to airframe) are classified by logistic regression modeling and artificial neural network analysis. From the analysis, it can be concluded that SUAS damage is a random event that cannot be predicted with …

A Study Of Queuing Theory In Low To High Rework Environments With Process Availability, Adam J. Brown

Theses and Dissertations--Manufacturing Systems Engineering

In manufacturing systems subject to machine and operator resource constraints the effects of rework can be profound. High levels of rework burden the resources unnecessarily and as the utilization of these resources increases the expected queuing time of work in process increases exponentially. Queuing models can help managers to understand and control the effects of rework, but often this tool is overlooked in part because of concerns over accuracy in complex environments and/or the need for limiting assumptions. One aim of this work is to increase understanding of system variables on the accuracy of simple queuing models. A queuing model …

Impact Of Rotated Aisles On Travel Distance In Manufacturing Facilities, Dale Masel, Samantha Hedges

12th IMHRC Proceedings (Gardanne, France – 2012)

To design a facility, expected flows between the resources is one of the most important input. Flows are usually calculated given some statistics of previous periods or from the expected demand and the process required. However, in a refurbishing and recycling facility, flows are very fluctuating and not trivial to predict. The quantity produced by such facility not only depends on the demand but also on the supplies which are returned products under guaranty or discarded products after their end-of-use. The uncertainty and the variability on these supplies are often higher than the one on the demand which makes it …

Simulation-Based Performance Improvement Of A Defense Logistics Warehouse, Banu Y. Ekren, Gerald W. Evans, Sunderesh S. Heragu, John S. Usher

12th IMHRC Proceedings (Gardanne, France – 2012)

Warehouses play a critical role in supply chains. They serve as a vital link between manufacturers and customers. In this study, we investigate performance of the largest warehouse (Eastern Distribution Center - EDC) of the Defense Logistics Agency (DLA) located in New Cumberland, PA and propose a near optimum design for the receiving area of the warehouse to improve its performance. First, we develop a simulation model of the system. Second, we interface an optimization model with the simulation in order to optimize the number of people working at the induction stations. In the optimization model, our goal is to …

Optimal Design Of Container Terminal Layout, Debjit Roy, Ren´E De Koster

12th IMHRC Proceedings (Gardanne, France – 2012)

Due to rapid growth in foreign trade using sea vessels, there is a growing focus in improving the infrastructure and operational efficiencies at the container terminals. Particularly, the operational responsiveness of loading and unloading of containers, affects the vessel idle times and profitability of the shipping liners. In this research, we deter- mine optimal stack layout design, which minimizes the container unload times using Automated Guided Vehicles (AGVs). To analyze alternate stack layout designs, we develop integrated queuing network models that capture the stochastic interactions among the container terminal processes (quayside, vehicle transport, and stack side), and provides realistic estimates …

Cycle Time Models For Aisle Changing As/Rs Considering Acceleration/Deceleration, Jörg Oser

12th IMHRC Proceedings (Gardanne, France – 2012)

In multi-aisle AS/RS systems one or more S/R machines serve several aisles with storage racks on both sides of the aisle. An important feature of multi-aisle configurations are aisle changing devices with transfer cars, curve guided aisle switching mechanisms or closed loop rail tracks with curved sections for a two-aisle layout. These systems offer an economic solution, when the number of storage and retrieval transactions is low and storage volume is high. One or several S/R machines each serving a specified number of aisles can be arranged in various layouts to meet the required storage capacity and throughput.

The Order Picking Problem In Fishbone Aisle Warehouses, Melih Celik, Haldun Sural

12th IMHRC Proceedings (Gardanne, France – 2012)

A recent trend in the layout design of unit load warehouses is the application of layouts without conventional parallel pick aisles and straight middle aisles. Two examples for such designs are flying- V and fish bone designs for single and dual command operations. In this study, we consider the same layout types under the case of multiple-item pick lists and show that, for both layout types, the routing problem can be solved in polynomial time. We also propose simple heuristics for this problem inspired by those put forward for parallel-aisle warehouses. Our computational results reveal that under certain cases, fish …

How To Choose An Order-Picking System, Marita Ellinger, Tim Geißen, Detlef Spee

12th IMHRC Proceedings (Gardanne, France – 2012)

Order-Picking-Systems are the parts of material flow systems, which have the largest variance of deployment alternatives. Since a long time there have been many attempts to systematize the way of identification of the order-picking- ystem that the “correct” solution can be found. The previous methods could not be enforced universally. Thus nearly all the material handling system suppliers have their own approach to find the right system, as it turned out at a market analysis of Fraunhofer IML. With the presented concept of finding a solution, a structured, fast method for system identification shall be presented. A stepwise approach to …

Evaluation Of Environmental Benefits Of Che Emerging Technologies By Using Lca, Nenad Zrnić, Andrija Vujičić

12th IMHRC Proceedings (Gardanne, France – 2012)

In the era of climate change combat transport industry is recognized as a sector with one of the largest environmental footprints. A part of transport industry is container shipping and handling division, which is currently growing with the fastest rate. This massive growth of container sector is due to containers pouring from Asia, mainly from China. Thus, container port operations are also experiencing significant increase in port emissions. This fact puts port authorities in position to find a way to reduce environmental impact of port operations and at the same time withhold increase in number containers being handled. In response …