Digital Commons Network^™

A Methodology For Evaluating And Enhancing C4i Networks, Christine C. Davis

Theses and Dissertations

This effort focuses on expanding the bottleneck links of an existing C4I network to meet projected demands. The minimum cost-maximum flow algorithm is used to identify bottlenecks. A decision analysis approach enables the mapping of performance objectives for a network expansion into measurable attributes within the structure of a value hierarchy. A multi-attribute value function combines these measures into an overall system effectiveness measure. This allows for an evaluation of the impact of potential upgrade components on the system. A knapsack model imposes budgetary constraints on the selection of components. This methodology allows for the design of an optimized system …

Transportation Modeling Of Remote Radar Sites And Support Depots, Sonia E. Leach

Theses and Dissertations

The North Warning System (NWS), a joint program of the United States Air Force (USAF) and the Royal Canadian Air Force (RCAF), is responsible for the maintenance of 47 remote radar sites across northern Canada. NWS's current airlift operations, which support the radar maintenance activities, consist of both helicopters and fixed wing aircraft positioned at five support depots. This thesis considers whether a reconfiguration of these support depots and the assignment of radar sites to them can result in either an airlift or total cost savings for NWS. Mixed integer linear programming models were formulated to address the questions surrounding …

The Application Of Statistical Process Control To Departure Reliability Improvement, Liu W. Chieh

Theses and Dissertations

This research effort focuses on applying statistical process control (SPC) techniques to the departure reliability improvement process for Air Mobility Command, Mission Reliability Office. Basic SPC methods, including Pareto analysis, cause and effect diagrams, and control charts are determined to be effective tools for analyzing and assessing departure reliability. In addition, two more alternative measures of effectiveness for departure reliability are evaluated and compared using AMC's data. SPC methods are also shown to be useful in assessing in performance and in determining the reporting frequency for on-time performance information. Additional statistical analyses are conducted, including on-way analyses of variance, hypothesis …

System Comparison Procedures For Automatic Target Recognition Systems, Anne E. Catlin

Theses and Dissertations

Estimating the performance of an automatic target recognition (ATR) system in terms of probability of successful target identification involves extensive image collection and processing, which can be very time-consuming and expensive. We investigate the Wald sequential test for the difference in two proportions as a sample size-reducing alternative to ranking and selection and the classical method of comparing binomial confidence intervals. The test is modified for the multiple pairwise comparison of four systems, and is applied to actual data to compare different configurations of the Moving and Stationary Target Acquisition and Recognition (MSTAR) System.

Analysis Of A Methodology For Linear Programming Optimality Analysis, Chanseok Jeong

Theses and Dissertations

The methodology of Johnson, Baner, Moore, and Grant can be applied to large scale linear programming models. A methodology for optimality analysis of linear programs was developed to create metamodels using response surface methodology techniques such as experimental design and least squares regression. A metamodel consists of a simple equation which is able to predict the optimal objective function value of a linear program. What is needed is some large scale application of the techniques to verify how accurate they are. In the research, I plan to use the large scale LP model, STORM. I use the "Hot Start" idea …

A Cercla-Based Decision Support System For Environmental Remediation Strategy Selection, Brian J. Grelk

Theses and Dissertations

The Idaho National Environmental Engineering Laboratory (INEEL), operating in conjunction with the Department of Energy (DOE), faces with the complex decision of selecting an environmental remediation strategy for the Subsurface Disposal Area (SDA) of the Radioactive Waste Management Complex (RWMC). This research uses value-focused thinking and multiattribute preference theory techniques to produce a decision analysis model to aid the decisionmakers as they select a remediation strategy. A deterministic analysis using expert opinion and the best available engineering data demonstrates the model's capabilities. The model ranks 27 specific remediation strategies based on how well they meet CERCLA's five balancing criteria: implementability, …

Turkish Air Mobility Modeling, Huseyin Topcuoglu

Theses and Dissertations

The aim of this research is to provide a tactical mobility model which is user friendly and flexible so the user is able to change the inputs, and evaluate the situation with the projected data for an operational plan. Thus, the users can analyze their system by using the model to see whether or not mobility requirements can be met within a definite time frame, and how long it takes to satisfy the requirements. Generalized Air Mobility Model (GAMM) was chosen to model TAMC's airlift system and has been found suitable for application to TUAF mobility problems. The software enables …

Decision Support Model To Select The Optimal Municipal Solid Waste Management Policy At United States Air Force Installations, Johnathon L. Dulin

Theses and Dissertations

The United States Air Force has recently defined three objectives in developing strategies regarding the management of municipal solid waste at the base level. They are: (1) 50 percent reduction in total waste generated, from a 1992 baseline amount, by 1999; (2) 50 percent recycling of all waste generated, beginning in 1999; and, (3) a minimum cost program. With these objectives in mind, base environmental engineers must take appropriate actions in an effort to develop a program that meets these goals. Through consultations with base environmental managers, as well as research of the available literature, a decision support model was …

Analyzing Remediation Technologies For Department Of Energy Sites Contaminated With Dnapl Pollutants, Anthony F. Papatyi

Theses and Dissertations

The Department of Energy is in the process of conducting a Remedial Investigation/Feasibility Study for a site contaminated with Dense Non-Aqueous Phase Liquid (DNAPL) pollutants at their Paducah Kentucky facility. A major part of this effort is the screening of alternative technologies. This thesis effort focuses on acquiring insight into a number of remediation technology trains that are candidates for the Paducah site. This insight is used to recommend and justify the screening of candidate technology trains. The research makes use of two decision analysis models (one is deterministic, the other is probabilistic) built to provide a quantitative assessment of …

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 …

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 …

Lithographers' Opinions About Waterless Lithography, Devang Pranlal Mehta

Dissertations and Theses @ UNI

The purposes of this study were to identify the advantages and disadvantages of waterless litho in comparison with traditional litho, to solve the controversial issues, to forecast the growth of waterless litho, and to inform graphic arts professionals about it. The problem of this research was to identify and measure perceived controversial issues for using the waterless litho process. These controversial issues were related to the return on investment and operating costs involved, productivity, quality of images, eco-friendliness, and technical problems associated with waterless litho.

Due to the fact that waterless litho was a developing technology and some controversial issues …

Perceptions Of Businesses On Environmental Regulatory Information, Kimberly K. Gunderson

Dissertations and Theses @ UNI

The purpose of this study was to determine the source and amount of information that a sample of businesses receive on environmental regulatory topics and from what sources they would prefer to receive this information. More specifically, the study demonstrated the discrepancy between the sources from which businesses currently receive their information and the sources from which they would prefer to receive it. The study also addressed how relevant this information was to the businesses and with which regulations the businesses were the most and least knowledgeable. The study was done by conducting a mail-back survey of 500 Iowa small …

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 …