Operations Research, Systems Engineering and Industrial Engineering Commons^™

Modeling And Analyzing The Effect Of Ground Refueling Capacity On Airfield Throughput, W. Heath Rushing

Theses and Dissertations

This thesis develops five analytical models to understand the current ground refueling process, to optimize the airfield configuration and to determine the refueling policy which maximizes throughput, the primary measure of airfield efficiency. This study models the airfield refueling process as a continuous time Markov process to adequately represent the inherent stochastic nature of the transitory ground refueling system and provide an analytical evaluation of various airfield configurations. Also, the study provides an optimal refueling policy to minimize the number of aircraft on the ground which in turn minimizes the average amount of time aircraft spend on the ground in …

Statistical Modeling And Optimization Of Nuclear Waste Vitrification, Todd E. Combs

Theses and Dissertations

This thesis describes the development of a methodology to minimize the cost of vitrifying nuclear waste. Pacific Northwest Laboratory (PNL) regression models are used as baseline equations for modeling glass properties such as viscosity, electrical conductivity, and two types of durability. Revised PNL regression models are developed that eliminate insignificant variables from the original models. The Revised PNL regression model for electrical conductivity is shown to better predict electrical conductivity than the original PNL regression model. Neural networks are developed for viscosity and the two types of durability, PCT-B and MCC-1 B. The neural network models are shown to outperform …

Acuta Enews February 1997, Vol.26, No. 2

ACUTA Newsletters

In This Issue

Call for Nominations for 1997-98

ACUTA Board of Directors

Effective Presentations

Board Report

Welcome New Members

Is It a Virus- Or a Hoax?

Vendor Liaison Committee

DC at a Glance

FCC Designates Wireless Spectrum for School

FCC Extends Campus Station License Terms

Coming Soon to Your IXC: 10XXX Changes

Optimizing Airborne Area Surveillance Asset Placement, Douglas E. Fuller

Theses and Dissertations

Currently there is no automated planning tool for the optimum positioning of USAF area surveillance assets for a theater level campaign. This research seeks to find the optimum or near optimum placement of the limited USAF airborne surveillance assets against a theater level target set. The problem of finding the optimum orbit points can be modeled as a classic maximal covering location problem (MCLP). Operational constraints on the placement of surveillance aircraft can be handled by preprocessing the potential orbit points to eliminate infeasible orbit points. Heavy emphasis is placed on preprocessing the data to reduce problem size and hence …

Experiments In Aggregating Air Ordnance Effectiveness Data For The Tacwar Model, James E. Parker

Theses and Dissertations

An interactive MS Access&trademark; based application that aggregates the output of the SABSEL model for input into the TACWAR model is developed. The application was developed following efforts to create a functional approximation of the SABSEL data using neural networks, statistical networks, and traditional statistical techniques. These approximations were compared to a look-up table methodology on the basis of accuracy, (RMSE

A Cost Impact Assessment Tool For Pfs Logistics Consulting, Angela P. Giddings

Theses and Dissertations

Response surface methodology (RSM) is used for optimality analysis of the cost parameters in mixed integer linear programming. This optimality analysis goes beyond traditional sensitivity and parametric analysis in allowing investigation of the optimal objective function value response over pre-specified ranges on multiple problem parameters. Design of experiments and least squares regression are used to indicate which cost parameters have the greatest impact on the optimal objective function value total cost-and to approximate the optimal total cost surface over the specified ranges on the parameters. The mixed integer linear programming problems of interest are the large-scale problems in supply chain …

Applying Tabu Heuristic To Wind Influenced, Minimum Risk And Maximum Expected Coverage Routes, Mark R. Sisson

Theses and Dissertations

The purpose of this thesis is to provide Air Combat Command a method for determining the number of predator unmanned aerial vehicles (UAVs) required to cover a pre-selected target. Extending previous research that employs reactive TABU search methods for deterministic vehicle routing problems, this thesis incorporates wind effects that can significantly alter the travel times for any given scenario. Additionally, it accounts for possible attrition by introducing minimum risk route and expected number of target covered to the objective function. The results of the TABU search and subsequent Monte-Carlo simulation: gives the number of predator's required to cover a target …

Sensitivity Of Availability Estimates To Input Data Characterization, Darren P. Durkee

Theses and Dissertations

Reliability analysts are often faced with the challenge of characterizing the behavior of system components based on limited data. Any insight into which model input data is most significant and how much data is necessary to achieve desired accuracy requirements will improve the efficiency and cost effectiveness of the data collection and data characterization processes. This thesis assesses potential significant factors in the probabilistic characterization of component failure and repair behavior with respect to the effect on system availability estimates. Potential factors were screened for significance utilizing fractional. factorial and Plackett-Burman experimental designs for several system models developed using an …

Design, Simulation And Fabrication Of A Mems In-Situ Contactless Sensor To Detect Plasma Induced Damage During Reactive Ion Etching, Subramanian Ganesh

Theses

The present trend in the semiconductor industry is towards submicron devices. An inevitable process technique in achieving this is by reactive ion etching of the polysilicon gate. During RIE, the gate oxide may get damaged due to several causes. One of the main causes of the damage is the non-uniformity of the plasma. It is reported that these plasma inconsistencies are mainly due to electrode design and that they create spatial plasma potential fluctuation. These fluctuations are reported to be in the range of 10-20 Volts. By providing an in-situ monitoring of the wafers, the reliability of the device could …

Measuring The Need For Manufacturing Flexibility And Evaluating Its Economic Benefits, Navin Karwande

Theses

Flexible systems are known of enabling organizations to take advantage of diversified products, low volume production items with short life-cycles. They also improve the ability to respond to market changes. Flexibility has thus become a strategic manufacturing need in recent years.

Because of the high initial capital outlay involved, the selection of the appropriate flexible solution has become a critical issue. This thesis proposes a methodology to determine the most cost effective and feasible flexibility strategy. A flexibility audit is developed to analyze and evaluate the changes taking place in a facility's environment. These changes and a measurement scheme is …

Acuta Enews January 1997, Vol.26, No. 1

ACUTA Newsletters

In This Issue

Do You Have a Voice Mail Handbook?

A Few Words of Advice

Board Report

ACUTA Journal: Second Issue Topics

Membership Committee

Reimbursing Personal Calls

Editorial Board Named

DC at a Glance

WCU on the Cutting Edge

Interstate Long Distance Tariffs Eliminated

Block it, again

Welcome New Members

Analytical Models For Vehicle/Gap Distribution On Automated Highway Systems, Jacob Tsao, Randolph W. Hall, Indrajit Chatterjee

Faculty Publications

Highway congestion has in recent years become a pervasive problem for urban and suburban areas alike. The concept of Automated Highway Systems is based on the belief that integration of sensing, communication, and control technologies into vehicles and highways can lead to a large improvement in capacity and safety without requiring a significant amount of additional highway right-of-way. A fundamental determinant of Automated Highway Systems capacity is the vehicle-following rule, the rule that governs the behavior of vehicles traveling along a common lane (e.g., the spacing between any two longitudinally adjacent vehicles). Vehicle following affects the longitudinal capacity (achievable flow …

A New Model Of High Temperature Low Cycle Fatigue Life Prediction - Applicability With Low Alloy Steels, Tarun Goswami

Biomedical, Industrial & Human Factors Engineering Faculty Publications

Creep-fatigue data on low alloy steels were collected from National Research Institute for Metals (NRIM) Tokyo, Japan. These data were generated for lCr-Mo-V, 2.25Cr-Mo, and 9Cr-lMo steels under a wide range of test conditions. A new creep-fatigue life prediction method was developed and data compiled were assessed to examine the applicability of the new method. A brief review of the empirically based, phenomenological life prediction methods was presented where no method was found to be applicable universally to all the creep-fatigue data. The new model was developed within the viscosity concepts, in which the damage parameter was accounted for in …

Dwell Sensitivity Fatigue Behaviour Of High Temperature Materials, Tarun Goswami, G. R. Halford, D. W. Hoeppner

Biomedical, Industrial & Human Factors Engineering Faculty Publications

The dwell sensitivity fatigue behavior of six high temperature materials is examined in this paper: two stainless steels, 304L and 304, two tantalum alloys, Τ- Ι 11 and ASTAR 811C, pure nickel Ni 201 and a single crystal nickel-base superalloy, PWA 1480. The stainless steel alloys were found to be tensile dwell sensitive; however, a saturation in dwell sensitivity was found with the increase in strain range for all materials examined. At lower strain ranges the dwell cycles were producing lower lives than at higher strains, as found in the case of AISI SS 304 and two tantalum based alloys, …

Review Of Pit Nucleation, Growth And Pitting Corrosion Fatigue Mechanisms, Tarun Goswami, D. W. Hoeppner

Biomedical, Industrial & Human Factors Engineering Faculty Publications

This paper presents a review of the state of the art developments in the pitting corrosion fatigue of aircraft structural materials. Mechanisms that govern the nucleation and growth of pitting and corrosion fatigue (CF) are briefly addressed. Some of the developments made in the author's laboratories in proposing the fretting induced pit nucleation and growth mechanisms, analysis of the hidden corrosion constituents in fuselage joints and pitting corrosion fatigue crack growth (PCFCG) model are elucidated. An epistemology of the topic is presented which will be of assistance to the community working in this area.

Corrosion Fatigue Crack Growth Behavior Of Aircraft Materials, Tarun Goswami, D. W. Hoeppner

Biomedical, Industrial & Human Factors Engineering Faculty Publications

The effects of test parameters on the corrosion fatigue crack growth behavior of structural materials have been examined in this paper. Test parameters such as stress ratio, frequency, hold time, temperature, pH level of the media, and other parameters are known to alter the corrosion fatigue crack growth rates in structural materials. Numerous laboratory test variables that affect the crack growth and/or corrosion growth rates, which in an operating environment of an aircraft are not characterized, are reviewed. A summary of such information may help determine the inspection intervals of the new and aged airplanes, perform the inspections, and develop …

Two Parallel Finite Queues With Simultaneous Services And Markovian Arrivals, Srinivas R. Chakravarthy, S. Thiagarajan

Industrial & Manufacturing Engineering Publications

In this paper, we consider a finite capacity single server queueing model with two buffers, A and B, of sizes K and N respectively. Messages arrive one at a time according to a Markovian arrival process. Messages that arrive at buffer A are of a different type from the messages that arrive at buffer B. Messages are processed according to the following rules: 1. When buffer A(B) has a message and buffer B(A) is empty, then one message from A(B) is processed by the server. 2. When both buffers, A and B, have messages, then two messages, one from A …

Selecting The "Best" Using Data Envelopment Analysis, Timothy R. Anderson, Akin Uslu

Engineering and Technology Management Faculty Publications and Presentations

One of the most important strengths of Data Envelopment Analysis, (DEA), is that it allows almost complete freedom in the way that each decision making unit, (DMU), evaluates itself relative to its peers. This tends to result in many DMUs receiving a high efficiency score. Particularly when DEA is applied in a decision making context, it may be desirable to select a single option rather than determining the set of efficient alternatives in ranking efficient DMU or to Assist selecting a "best" DMU. Several extensions to DEA have been proposed and used. This paper examines, compares, and integrates a variety …

The Effects Of Human-Computer Communication Mode, Task Complexity, And Desire For Control On Performance And Discourse Organization In An Adaptive Task, Cristina Bubb-Lewis

Psychology Theses & Dissertations

The present study examined how different communication patterns affected task performance with an adaptive interface. A Wizard-of-Oz simulation (Gould, Conti, & Hovanyecz, 1983) was used to create the impression of a talking and listening computer that acted as a teammate to help participants interact with a computer application.

Four levels of communication mode were used which differed in the level of restriction placed on human-computer communication. In addition, participants completed two sets of tasks (simple and complex). Further, a personality trait, Desire for Control (DC), was measured and participants were split into high and low groups for analysis. Dependent measures …

An Aggregation Procedure For Simulating Manufacturing Flow Line Models, Paul Savory, Gerald Mackulak

Department of Industrial and Management Systems Engineering: Faculty Publications

We develop a formal method for specifying an aggregate discrete-event simulation model of a production flow line manufacturing system. The methodology operates by aggregating production stations or resources of a flow line. Determining the specifications for representing the aggregated resources in a simulation model is the focus of our presentation. We test the methodology for a set of flow lines with exponentially distributed arrival and service times. Comparisons between analytical and simulation results indicate the aggregation approach is quite accurate for estimating average part cycle time.

Asynchronous Distance Learning Technology: The Instructor's Perspective, Earl Alexander Evans

Masters Theses

"Advances in communications, computer technology and human-computer interfaces have enabled concurrent advances in Web-based education. A number of case studies concerning applications of Web-based education for both distance learning and on-campus programs have been published. Primarily, these studies have focused on individual assessments of the Web-based technologies. In addition, these published studies have generally highlighted the successes while little discussion about failed attempts has been presented in the literature.

In contrast, this thesis provides a broad-based assessment of applied Web technology for higher education. This research was conducted via a survey completed by twenty five university and college faculty from …

As-Is Evaluation & Process Design Of The 17/18 Foot Refrigerator At General Electric In Decatur, Alabama, Yongke Thio, Nicole Hagood

Honors Capstone Projects and Theses

No abstract provided.

An Integrated Approach To Simulation And Activity-Based Costing For Evaluating Alternative Manufacturing Cell Designs, Robert Williams, Paul Savory, Rodney Rasmussen

Department of Industrial and Management Systems Engineering: Faculty Publications

One effective technique for improving manufacturing efficiency involves the application of group technology part families and manufacturing cells. Selection of the best or optimum configuration of the manufacturing cell relies on the experience and judgment of the cell designer. This paper describes how activity-based costing (ABC) concepts can be integrated into a discrete-event simulation model and be used to evaluate manufacturing cell configurations. The output of the combined ABC simulation model provides a detailed “Bill of Activity” which allows the cell designer to consider costs as a critical factor in the cell design problem. Alternative cell configurations studied in this …

Selecting For Random Drug Testing At Union Pacific Railroad, Jennifer Meyer, Paul Savory

Department of Industrial and Management Systems Engineering: Faculty Publications

Many industries have recently implemented programs to detect and deter the use of recreational drugs in the workplace. The transportation industry has received careful government attention, particularly where the safety of the public may be seriously affected by employees who use drugs. Following federal guidelines, Union Pacific Railroad first implemented a random drug-testing plan in 1990. Because the assigned jobs, shifts, and work locations of many railroad employees change frequently, defining the selection population was particularly challenging. In its continuing efforts to validate and improve this plan, Union Pacific Railroad sought an external evaluation to determine the fairness of its …

Simulating Queue Scheduling Policies For A Spacecraft Simulator, Paul Savory, Gene Saghi

Department of Industrial and Management Systems Engineering: Faculty Publications

The mission of the Cassini spacecraft is a unique opportunity to gain insights into major scientific questions about Saturn, the creation of the solar system, and the conditions that led to life on Earth. In preparation for the launch, NASA's Jet Propulsion Laboratory developed a software simulator to emulate the hardware data-control system of the spacecraft. Its primary use is to validate and verify commands that will be transmitted to the spacecraft. To improve the performance of the simulator, we used the SIMAN simulation language to model numerous queue-scheduling policies. Implementation of the simulation results combined with a software-code redesign …

Technology Acquisition And Utilization In Metal Goods, N. Alp, B. Alp, Yildirim Omurtag

Engineering Management and Systems Engineering Faculty Research & Creative Works

This paper analyzes the technology acquisition and utilization process in metal goods manufacturing organizations through a survey instrument which is conducted in the Mid-West region of the US. The goal of this study is to identify the channels, types, reasons, impacts, difficulties, and limitations of technology acquisition and utilization process in metal goods sector.

Artificial Neural Network Based Model For Computation Of Injection Mould Complexity, Rawin Raviwongse, Venkat Allada

Engineering Management and Systems Engineering Faculty Research & Creative Works

The cost of injection mould construction depends primarily on the mould complexity. The ability to estimate the mould complexity before releasing the final drawings for construction purposes will greatly help the designers to understand the implications of their design on cost. Mould complexity depends on several factors such as part geometry, parting line, materials, and number of cavities per mould. In most industries, the mould complexity evaluation is performed manually based on past experiences of mould makers. Faced with a shortage of experienced mould makers, there is a pressing need for development of computer-aided tools for mould complexity evaluation. In …

Innovative Applications Of Groupware For Solving Engineering Design Problems, Leslie F. Monplaisir, Colin Othniel Benjamin, Choayuan Lu

Engineering Management and Systems Engineering Faculty Research & Creative Works

In these case studies, groupware was used as a group decision-making environment to assist teams evaluating a quality function deployment framework for risk management and agile manufacturing system designs. In the first case, teams identified customers' requirements and risk categories for a research and development project. They then mapped the relationship between these customer requirements and the risk categories. In the second case, cross-functional teams collaborated in selecting the best layout for a cellular manufacturing facility. These experimental findings support the use of group decision systems by design and project teams required to manage R&D projects or to design agile …

Self-Assessment Of Total Quality Management Programs, Hung Yi Wu, Henry Allen Wiebe, John Politi

Engineering Management and Systems Engineering Faculty Research & Creative Works

Total quality management (TQM) has been increasingly accepted as a management philosophy. Criteria such as those contained in the Malcolm Baldrige National Quality Award (MBNQA) often guide TQM implementation. However, reports indicate that fully assessing TQM efforts is difficult and hiring experts to help with this task is expensive. Using survey instruments is an attractive alternative to full-scale assessment. Despite the availability of many papers covering organizational performance assessment, few instruments specifically address TQM evaluation. Furthermore, none of the TQM assessment instruments has been subjected to rigorous validation; thus, only modest confidence can be placed in results obtained from their …

Hydro Unit Commitment In Hydro-Thermal Optimization, Chao-An Li, E. Hsu, Chung-Li Tseng, A. J. Svoboda, R. B. Johnson

Engineering Management and Systems Engineering Faculty Research & Creative Works

In this paper, the authors develop a model and technique for solving the combined hydro and thermal unit commitment problem, taking into full account the hydro unit dynamic constraints in achieving overall economy of power system operation. The combined hydrothermal unit commitment problem is solved by a decomposition and coordination approach. Thermal unit commitment is solved using a conventional Lagrangian relaxation technique. The hydro system is divided into watersheds, which are further broken down into reservoirs. The watersheds are optimized by network flow programming (NFP). Priority-list-based dynamic programming is used to solve the hydro unit commitment (HUC) problem at the …