Operations Research, Systems Engineering and Industrial Engineering Commons^™

Remote Usability Testing - A New Approach Facilitated By Virtual Worlds, Kapil Chalil Madathil

All Theses

Synchronous remote usability testing, involves a facilitator conducting a usability test in real time, interacting with a participant who is remote. This study proposes a new methodology for conducting these studies using a three-dimensional virtual world, Wonderland, and compares it with two other commonly used synchronous usability test methods: the traditional lab approach and WebEx, a web-based conferencing and screen sharing approach.
The study involved 48 participants in total, 36 test subjects and 12 test facilitators. These 36 were equally divided among the three environments with the 12 test facilitators being paired with one participant in each of the environments. …

Development Of A Task Assignment Tool To Customize Job Descriptions And Close Person-Job Fit Gaps, Bryan W. Booker

Dissertations

Does the knowledge worker fit the job or should the job fit the knowledge worker? This research developed a methodology and a tool to customize a knowledge worker’s job design to better fit their knowledge, skills, abilities and characteristics. The research outcomes support the customization of the job design to improve person-job fit, the documentation of the customized job design as a position description, and the use of a structured person-task assignment process. The recommended task assignment process includes a job aid that uses multivariate equations to predict expected task performance. Data were collected from two knowledge worker sub-groups: lean …

Estimation And Control Of Robotic Radiation-Based Processes, Fan Zeng

All Dissertations

This dissertation presents a closed-loop control and state estimation framework for a class of distributed-parameter processes employing a moving radiant actuator. These radiation-based processes have the potential to significantly reduce the energy consumption and environmental impact of traditional industrial processes. Successful implementation of these approaches in large-scale applications requires precise control systems. This dissertation provides a comprehensive framework for: 1) integration of trajectory generation and feedback control, 2) online distributed state and parameter estimation, and 3) optimal coordination of multiple manipulated variables, so as to achieve elaborate control of these radiation-based processes for improved process quality and energy efficiency.
The …

Simulation And Mathematical Modeling To Support Community-Wide Evacuation Decisions For Multiple Population Groups, Jun Duanmu

All Dissertations

Evacuating a large population from an at-risk area has been the subject of extensive research over the past few decades. In order to measure trip completion and total evacuation times accurately, most researchers have implemented some combination of simulation and optimization methods to provide vehicular flow and congestion data. While the general at-risk population comprises the majority of travelers on the road network, there are often specific groups to consider when assessing the ability to evacuate an entire population. In particular, healthcare facilities (e.g., hospitals) may require evacuation, and the trip times may become an important health issue for patients …

Principal Component Analysis Based Image Fusion Routine With Application To Stamping Split Detection, Yi Zhou

All Dissertations

This dissertation presents a novel thermal and visible image fusion system with application in online automotive stamping split detection. The thermal vision system scans temperature maps of high reflective steel panels to locate abnormal temperature readings indicative of high local wrinkling pressure that causes metal splitting. The visible vision system offsets the blurring effect of thermal vision system caused by heat diffusion across the surface through conduction and heat losses to the surroundings through convection. The fusion of thermal and visible images combines two separate physical channels and provides more informative result image than the original ones.
Principal Component Analysis …

Prioritizing Patients For Emergency Evacuation From A Healthcare Facility, Ashley Childers

All Dissertations

The success of a healthcare facility evacuation depends on communication and decision-making at all levels of the organization, from the coordinators at incident command to the clinical staff who actually carry out the evacuation. One key decision is the order in which each patient is chosen for evacuation. While the typical planning assumption is that all patients are to be evacuated, there may not always be adequate time or resources available to move all patients. In these cases, prioritizing or ordering patients for evacuation becomes an extremely difficult decision to make. These decisions should be based on the current state …

Investigation Into Current Efficiency For Pulse Electrochemical Machining Of Nickel Alloy, Yu Zhang

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

INVESTIGATION INTO CURRENT EFFICIENCY FOR PULSE ELECTROCHEMICAL MACHINING OF NICKEL ALLOY

Yu Zhang, M.S.

University of Nebraska, 2010

Adviser: Kamlakar P. Rajurkar

Electrochemical machining (ECM) is a nontraditional manufacturing process that can machine difficult-to-cut materials. In ECM, material is removed by controlled electrochemical dissolution of an anodic workpiece in an electrochemical cell. ECM has extensive applications in automotive, petroleum, aerospace, textile, medical, and electronics industries.

Improving current efficiency is a challenging task for any electro-physical or electrochemical machining processes. The current efficiency is defined as the ratio of the observed amount of metal dissolved to the theoretical amount predicted from …

Decentralized Resource Allocation And Scheduling Via Walrasian Auctions With Negotiable Agents, Huaxing Chen, Hoong Chuin Lau

Research Collection School Of Computing and Information Systems

This paper is concerned with solving decentralized resource allocation and scheduling problems via auctions with negotiable agents by allowing agents to switch their bid generation strategies within the auction process, such that a better system wide performance is achieved on average as compared to the conventional walrasian auction running with agents of fixed bid generation strategy. We propose a negotiation mechanism embedded in auctioneer to solicit bidders’ change of strategies in the process of auction. Finally we benchmark our approach against conventional auctions subject to the real-time large-scale dynamic resource coordination problem to demonstrate the effectiveness of our approach.

The Bi-Objective Master Physician Scheduling Problem, Aldy Gunawan, Hoong Chuin Lau

Research Collection School Of Computing and Information Systems

Physician scheduling is the assignment of physicians to perform different duties in the hospital timetable. In this paper, the goals are to satisfy as many physicians’ preferences and duty requirements as possible while ensuring optimum usage of available resources. We present a mathematical programming model to represent the problem as a bi-objective optimization problem. Three different methods based on ε–Constraint Method, Weighted-Sum Method and HillClimbing algorithm are proposed. These methods were tested on a real case from the Surgery Department of a large local government hospital, as well as on randomly generated problem instances. The strengths and weaknesses of the …

A Decision Theoretic Approach To Data Leakage Prevention, Janusz Marecki, Mudhakar Srivastava, Pradeep Reddy Varakantham

Research Collection School Of Computing and Information Systems

In both the commercial and defense sectors a compelling need is emerging for rapid, yet secure, dissemination of information. In this paper we address the threat of information leakage that often accompanies such information flows. We focus on domains with one information source (sender) and many information sinks (recipients) where: (i) sharing is mutually beneficial for the sender and the recipients, (ii) leaking a shared information is beneficial to the recipients but undesirable to the sender, and (iii) information sharing decisions of the sender are determined using imperfect monitoring of the (un)intended information leakage by the recipients.We make two key …

Effect Of Human Biases On Human-Agent Teams, Praveen Paruchuri, Pradeep Reddy Varakantham, Katia Sycara, Paul Scerri

Research Collection School Of Computing and Information Systems

As human-agent teams get increasingly deployed in the real-world, agent designers need to take into account that humans and agents have different abilities to specify preferences. In this paper, we focus on how human biases in specifying preferences for resources impacts the performance of large, heterogeneous teams. In particular, we model the inclination of humans to simplify their preference functions and to exaggerate their utility for desired resources, and show the effect of these biases on the team performance. We demonstrate this on two different problems, which are representative of many resource allocation problems addressed in literature. In both these …

Preparation Of Coated Microtools For Electrochemical Machining Applications, Ajaya K. Swain

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

PREPARATION OF COATED MICROTOOLS FOR ELECTROCHEMICAL MACHINING APPLICATIONS

Ajaya K. Swain, M.S. University of Nebraska, 2010

Advisor: K.P. Rajurkar

Coated tools have improved the performance of both traditional and nontraditional machining processes and have resulted in higher material removal, better surface finish, and increased wear resistance. However, a study on the performance of coated tools in micromachining has not yet been adequately conducted. One possible reason is the difficulties associated with the preparation of coated microtools. Besides the technical requirement, economic and environmental aspects of the material and the coating technique used also play a significant role in coating microtools. …

A Methodology To Evaluate Obsolete Inventory In Health Care, Rama Thummalapalli

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

Many organizations are currently facing inventory management problems such as distributing inventory on-time and maintain the correct inventory levels to satisfy the customer or end users. Organizations understand the need for maintaining the accurate inventory levels but sometimes fall short leading a wide performance gap in maintaining inventory accurately. The inventory inaccuracy can consume much of the investment on purchasing inventory and many times leads to excessive inventory. The research objective of thesis is to provide a decision making criteria to the management for closing or maintaining the warehouse based on basic purchasing and holding cost information. The specific objectives …

Acuta Enews July 2010, Vol 39, No. 7

ACUTA Newsletters

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From ACUTA Headquarters: FCC: Traveling with Wireless Phones .....Jeri A. Semer, CAE, Executive Dir.

Why Should You Visit the ACUTA Community Often?

Tech Talk: The lnternet Just Keeps on Growing ....Kevin Tanzillo, Dux PR

Hurricane Preparedness Checklist

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Second-Generation International Space Station Total Organic Carbon Analyzer Verification Testing And On-Orbit Performance Results, Nicole L. Bentley, Evan A. Thomas, Michael Van Wie, Chad Morrison

Mechanical and Materials Engineering Faculty Publications and Presentations

The International Space Station (ISS) total organic carbon analyzer (TOCA) is designed to autonomously assess recovered water quality by providing an indication of total organic carbon (TOC). The current TOCA has been on the ISS since November 2008. Functional checkout and operations revealed complex operating considerations. Specifically, failure of the hydrogen (H2) catalyst resulted in development of an innovative oxidation analysis method. This method reduces activation time and limits the H2 produced during analysis, while retaining the ability to indicate TOC concentrations within 25% accuracy. Subsequent testing and comparison to archived samples returned from the station and tested on the …

Developing Sustainable Life Support System Concepts, Evan A. Thomas

Mechanical and Materials Engineering Faculty Publications and Presentations

Sustainable spacecraft life support concepts may allow the development of more reliable technologies for long-duration space missions. Currently, life support technologies at different levels of development are not well evaluated against each other, and evaluation methods do not account for long-term reliability and sustainability of the hardware. This paper presents point-of-departure Sustainable System Mass (SSM) evaluation criteria for life support systems that may allow more robust technology development, testing, and comparison. An example sustainable water recovery system concept is presented.

Effective Heuristic Methods For Finding Non-Optimal Solutions Of Interest In Constrained Optimization Models, Steven O. Kimbrough, Ann Kuo, Hoong Chuin Lau

Research Collection School Of Computing and Information Systems

This paper introduces the SoI problem, that of finding nonoptimal solutions of interest for constrained optimization models. SoI problems subsume finding FoIs (feasible solutions of interest), and IoIs (infeasible solutions of interest). In all cases, the interest addressed is post-solution analysis in one form or another. Post-solution analysis of a constrained optimization model occurs after the model has been solved and a good or optimal solution for it has been found. At this point, sensitivity analysis and other questions of import for decision making (discussed in the paper) come into play and for this purpose the SoIs can be of …

Optimizing And Benchmarking Returnable Container Processes Within An Automotive Distribution System, Camille Chism

Theses

An analysis of Reusable Packaging in automobile manufacturing facilities, as well as a comparison to other industries, shows that returnable container systems are not being fully utilized.

In this study, methods to return and track packaging materials for reuse are examined. Issues identified through surveys and interviews are summarized, and a recommendation to more fully utilize systems currently in place is proposed. An evaluation based on utilizing the current system will enable us to assign a cost to current operations, and may support an investment in improved systems and technologies.

Most of the companies surveyed gauge functionality based on whether …

Hybrid Time-Frequency Domain Analysis For Inverter-Fed Induction Motor Fault Detection, T. W. Chua, W. W. Tan, Zhaoxia Wang, C. S. Chang

Research Collection School Of Computing and Information Systems

The detection of faults in an induction motor is important as a part of preventive maintenance. Stator current is one of the most popular signals used for utility-supplied induction motor fault detection as a current sensor can be installed nonintrusively. In variable speeds operation, the use of an inverter to drive the induction motor introduces noise into the stator current so stator current based fault detection techniques become less reliable. This paper presents a hybrid algorithm, which combines time and frequency domain analysis, for broken rotor bar and bearing fault detection. Cluster information obtained by using Independent Component Analysis (ICA) …

A Predictive Game Theoretic Model To Assess Us - Russian Response To An Islamic Safe-Haven In The Caucasus Region, Christopher Wayne Hartline

Computational Modeling & Simulation Engineering Theses & Dissertations

The thesis examines possible US and Russian policy decisions following the establishment of an Islamist safe-haven in Chechnya. Conflicting national policies affect the possibility of a negotiated settlement. Domestic and international political considerations constrain the decision-making of the two nations. The author applies game theory to examine the sequential decision-making of the two nations. The extensive form model draws outcome payoff values from a bounded uniform distribution. This approach naturally models uncertainty; and, it allows repeated probabilistic instantiations of the model. These instantiations produce a range of solutions. The most likely outcome was a negotiated settlement, generally following a tit-for-tat …