Engineering Commons^™

Dynamic Unmanned Aerial Vehicle (Uav) Routing With A Java-Encoded Reactive Tabu Search Metaheuristic, Kevin P. O'Rourke

Theses and Dissertations

In this paper we consider the dynamic routing of unmanned aerial vehicles (UAVs) currently in operational use with the US Air Force. Dynamic vehicle routing problems (VRP) have always been challenging, and the airborne version of the VRP adds dimensions and difficulties not present in typical ground-based applications. Previous UAV routing work has focused on primarily on static, pre-planned situations; however, scheduling military operations, which are often ad-hoc, drives the need for a dynamic route solver that can respond to rapidly evolving problem constraints. With these considerations in mind, we examine the use of a Java-encoded metaheuristic to solve these …

Cost-Benefit Analysis Of Cosolvent Flushing To Treat Groundwater Contamination Source Areas, Stacey L. Anason

Theses and Dissertations

Dense non-aqueous phase liquids (DNAPLs) in the zone beneath the water table can be a virtually permanent source of groundwater contamination that cannot be remediated by currently available technologies. Cosolvent flushing is a new technology that has the potential to remediate these sites and could pose a solution to the problem of DNAPL source areas. A computer model was developed to determine the cost and time to remediate an aquifer using cosolvent flushing. Included in the model is a module to calculate the costs of recycling the alcohol that is used as the cosolvent. The model was validated using site …

A Comparison Of Genetic Algorithm Parametrization On Synthetic Optimization Problems, Mehmet Eravsar

Theses and Dissertations

Meta-heuristics have been deployed to solve many hard combinatorial and optimization problems. Parameterization of meta-heuristics is an important challenging aspect of meta-heuristic use since many of the features of these algorithms cannot be explained theoretically. Experiences with Genetic Algorithms (GA) applied to Multidimensional Knapsack Problems (MKP) have shown that this class of algorithm is very sensitive to parameterization. Many studies use standard test problems, which provide a firm basis for study comparisons but ignore the effect of problem correlation structure. This thesis applies GA to MKP. A new random repair operator, which projects infeasible solutions into feasible region, is proposed. …

Quality Function Deployment From An Operations Research Perspective, Eve M. Burke

Theses and Dissertations

The methodology of Quality Function Deployment (QFD) is compared to operations analysis standards. Of special concern is how Air Combat Command (ACC) uses QFD for the Modernization Planning Process (MPP). ACC digresses from the traditional use of QFD for incorporating quality into manufacturing processes to use it as a planning tool. ACC's goal in implementing QFD is to incorporate the demands of the Air Force mission into the modernization planning effort. ACC's use of QFD to identify and quantify current deficiencies and quantify the value of alternative future solutions has led to the investigation of inconsistencies with QFD, both generally …

An Approach For Tasking Allocated Combat Resources To Targets, David A. Koewler

Theses and Dissertations

Tasking allocated combat aircraft to strike targets is a complicated and time-consuming process for combat planners. Currently, the process of scheduling missions is a two to four day process. To be able to respond quickly to the changing conditions of the battlefield, the military needs to compress the time that this process requires. Despite efforts to develop computer-based tools to automatically plan missions, combat planners still manually perform most of the tasking and scheduling of aircraft and targets. Unfortunately some of the tools currently available are perceived to be complicated and time consuming to use by the planners. They also …

Using Simulation To Model The Army Recruiting Station With Multi-Quality Prospects, Edward L. Mclarney

Theses and Dissertations

This thesis explores the application of simulation to the Army Recruiting Station. Included are the effects of leadership styles and policies, the effects of recruiters with different personality types, and differences in processing for varying types of recruits. Research included heavy emphasis into determining the effects of leadership on recruiter productivity. In addition, major changes were made to a previous simulation model. The changes allowed current research to be implemented into the simulation. This research is intended to help the United States Army Recruiting Command better understand how changes in the recruiting process and in leadership policies affect productivity.

Pilot Inventory Complex Adaptive System (Picas): An Artificial Life Approach To Managing Pilot Retention, Martin P. Gaupp

Theses and Dissertations

The retention of skilled pilots continues to be a problem that plagues the United States Air Force. After spending millions of dollars on training and education, it is disheartening to see the mass exodus of experienced aviators from the Air Force that has been occurring in the past decade. Many blame the economy, others the Air Force itself but few are able to accurately predict how or why they are all leaving. The current personnel models do not adequately determine retention rates. Complex adaptive systems theory, however, might provide some insight. By modeling the system at the pilot's level, allowing …

Portfolio Selection Of Innovative Technologies Via Life Cycle Cost Modeling, Scott C. Naylor

Theses and Dissertations

High technology firms are faced with the dilemma of deciding which products to develop, which generations of technology to pass over, and which products to skip entirely. As competition among these firms increases and the life cycles of technological products shorten, there exists a great deal of pressure to bring products rapidly to the market. As a result, recouping the costs of research and development (R & D) and earning a profit becomes increasingly uncertain. Traditional life cycle cost models do not directly address shortened life cycles, time to market, or learning curve issues; all are critical factors in the …

Solving The Multidimensional Multiple Knapsack Problem With Packing Constraints Using Tabu Search, Jonathan M. Romaine

Theses and Dissertations

This paper presents a methodology for solving military aircraft load-scheduling problems modeled as a multidimensional multiple knapsack problem, Because of the computational time associated with applying conventional algorithms to this type of problem, we employ tabu search to determine how much cargo a heterogeneous group of aircraft can carry. This study extends the previous work of Chocolaad in two areas. First, we modify Chocolaad's algorithms to solve the multiple (rather than the single) knapsack problem under the constraints he defined for the Airlift Loading Problem. Second, we drop his assumption of a homogeneous group of aircraft. We validate our model …

Visualizing Early-Stage Breast Cancer Tumors In A Mammographic Environment Through A 3-Dimensional Mathematical Model, Christopher B. Bassham

Theses and Dissertations

In response to the insidious and deadly nature of breast cancer and the less-than-perfect detection ability of mammography, we develop a mathematical model as a foundation to the long-term goal of improving early breast cancer detection. By using modeling and simulation to construct an accurate breast cancer tumor model, we hope to solve the problems associated with mammogram misdiagnosis and, perhaps as a by-product, lend insight to tumor development dynamics. The final tumor model, written in MATLAB, provides realistic tumor growth and 2-dimensional visualization of 3-dimensional structures. Earlier modeling attempts capture slices of the tumor in the 2-dimensional growth spaces. …

Expeditious Method For Estimating Cleanup Costs At Department Of Defense Installations In Korea, John M. Griffin

Theses and Dissertations

The purpose of this research was to develop and test a method that can be used to expeditiously estimate costs of hazardous waste site remediation at US DoD installations in Korea allowing decision-makers to formulate remediation strategy. This objective was addressed through answering the following questions: (1) What cost and time constraints do the decision-makers have in developing remediation cost estimates; (2) What degree of accuracy do the decision-makers require in cost estimates; (3) What estimating models are available for determining costs of remediation activities; (4) Have models been used to estimate remediation activities' costs at Korean installations; and (5) …

Heavy Truck Involvement In Traffic Accidents And Related Countermeasures, Jerry G. Pigman, Kenneth R. Agent

Kentucky Transportation Center Research Report

The objectives of this research study were to conduct a detailed analysis of truck accidents and recommend countermeasures to reduce the number and severity of this type of accident. Police reports for fatal accidents in which a truck was involved were reviewed for the period 1994 through 1997. Each accident report was reviewed and classified into types of accidents and causative factor categories. The most common accident involved another vehicle crossing the centerline into the path of a truck. The primary causative factor was related to the actions of the other driver, rather than the truck driver, in nearly two-thirds …

Kentucky Transportation Cabinet: Employee Satisfaction Survey Report, Bennett Tepper, Patsy Anderson

Kentucky Transportation Center Research Report

The purpose of this survey was to establish the baseline attitude of Kentucky Transportation Cabinet employees concerning work environment and morale.

Evaluation Of Corrugated Steel Pipe Culverts Ky 55, Shelby County, L. John Fleckenstein, David L. Allen

Kentucky Transportation Center Research Report

In February of 1998, the Kentucky Transportation Cabinet requested that the Kentucky Transportation Center investigate excessive deflection occurring in three aluminized Type 2 corrugated metal pipe culverts installed during the realigning and widening on KY 55. The pipes were initially inspected in February 1998. The embankments were only 50 percent completed and in several locations only one-half of the total length of the culvert had been installed, The scope of this project was increased after excessive deflections were observed in other structures throughout the project.

An Investigation Of The Recent Deterioration Of I-75 In Scott County, Allen H. Myers, David L. Allen, L. John Fleckenstein

Kentucky Transportation Center Research Report

In early January of 1999, approximately 15 miles ofl-75 in Scott County began to rapidly deteriorate. The existing pavement exhibited several potholes and delaminations. The worst section of deterioration fell approximately between milepoints 125 and 133.

In the latter part of January, the condition of the highway had declined to the point thatcorrective action was necessary. The worst sections were milled and patched with hotmixasphalt (HMA). Despite this temporary improvement to the pavement condition, adesire developed within the Department to investigate the cause of the deterioration inorder to prevent a future similar occurrence.

Therefore, personnel from the Division of Materials …

Sliding Mode Measurement Feedback Control For Antilock Braking Systems, Cem Unsal, Pushkin Kachroo

Electrical & Computer Engineering Faculty Research

We describe a nonlinear observer-based design for control of vehicle traction that is important in providing safety and obtaining desired longitudinal vehicle motion. First, a robust sliding mode controller is designed to maintain the wheel slip at any given value. Simulations show that longitudinal traction controller is capable of controlling the vehicle with parameter deviations and disturbances. The direct state feedback is then replaced with nonlinear observers to estimate the vehicle velocity from the output of the system (i.e., wheel velocity). The nonlinear model of the system is shown locally observable. The effects and drawbacks of the extended Kalman filters …

Electro-Hydrodynamic Pumped Hydraulic Actuation With Application To Active Vibration Control, Ahmad Reza Kashani, Sung Kang, Kevin P. Hallinan

Mechanical and Aerospace Engineering Faculty Publications

A new type of actuation device has been conceptualized that meets the needs of both large displacement, force and bandwidth within a package more compact than currently available magnetostrictive and stack-type piezoelectric actuators of similar rating. This concept relies on micro-scale electrohydrodynamic (EHD) pumping of a dielectric liquid within small channels. Configured as an actuator, the EHD pump(s) would be used to move fluid between two reservoirs—each having a compliant membrane that interfaces to the world to provide the means to achieve vibration cancellation or micro actuation.

Ordinarily limited to generating flow in macroscale applications, the EHD pump, when operating …

Resolving Problems In Engineering Ethics: Precept And Example, Joel C. Adair

Theses and Dissertations

This thesis has served to accomplish several objectives. First, a foundation was laid for the consideration of ethical factors in an engineering context. This was done by first establishing the need for ethical judgement in the engineering disciplines. A summary of several significant classical ethical theories followed, providing several tools with which to evaluate decisions that have ethical implications. Finally, the conclusion was made that the best framework for making ethical decisions is found in the application of the virtues espoused by the gospel of Jesus Christ.

Preparation Of A Zro₂-Al₂O₃ Nanocomposite By High-Pressure Sintering Of Spray-Pyrolyzed Powders, Rajiv S. Mishra, V. Jayaram, B. Majumdar, C. E. Lesher, A. K. Mukherjee

Materials Science and Engineering Faculty Research & Creative Works

ZrO2-Al2O3 powders were synthesized by spray pyrolysis. These powders were sintered at 1 GPa in the temperature range of 700Ç1100 ÉC. The microstructural evolution and densification are reported in this paper. The application of 1 GPa pressure lowers the crystallization temperature from ~850 to 700 ÉC. Similarly, the transformation temperature under 1 GPa pressure for <>g ê a Al2O3 reduces from ~1100 to 700Ç800 ÉC range, and that for t <>ê m ZrO2 reduces from ~1050 to 700Ç800 ÉC range. It was possible to ob-tain highly-dense nanocrystalline ZrO2-Al2O3 composite at temperatures as low as 700 ÉC. The effect of high …

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Building Services Engineering

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Liquid-Phase Catalytic Oxidation Of Unsaturated Fatty Acids , Hossein Noureddini, M Kanabur

Papers in Biomaterials

Liquid-phase catalytic oxidation of oleic acid with hydrogen peroxide in the presence of various transition metal/metal oxide catalysts was studied in a batch autoclave reactor. Azelaic and pelargonic acids are the major reaction products. Tungsten and tantalum and their oxides in supported and unsupported forms were used as catalysts. Alumina pellets and Kieselguhr powder were used as supports for the catalysts. Tungsten, tantalum, molybdenum, zirconium, and niobium were also examined as catalysts. Tertiary butanol was used as solvent. Experimental results concluded that tungsten and tungstic oxide are more suitable catalysts in terms of their activity and selectivity. The rate of …

Multi-Discipline Network Vulnerability Assessment, Karilynne Wallace

Theses and Dissertations

Air Force Space Command has a mission to provide real-time, survivable, and enduring communications, surveillance, environmental monitoring, navigation, and warning....according to Air Force Space Handbook - A War Fighters Guide to Space. In order to prevent disruption of the critical networks in Space Command, a vulnerability assessment must be performed. The set of components called a vulnerability set, which could cause network disruption, must be identified and prioritized. In order to move beyond subjective prioritization, implementation of a quantitative methodology that measures the value of each vulnerability set is needed. This thesis proposes a technique for vulnerability assessment of a …

Simsat: A Satellite System Simulator And Experimental Test Bed For Air Force Research, James E. Colebank, R. Dan Jones, Randall D. Pollak, Donald M. Mannebach, George R. Nagy

Theses and Dissertations

SIMSAT (the SIMulation SATellite) is an AFIT-sponsored program to develop a laboratory-based physical satellite simulator. SIMSAT supports experimentation in areas of attitude control, precision pointing, and vibration suppression. SIMSAT development began with the purchase of a three-axis gas bearing which simulates a torque-free space environment. SIMSAT subsystems provide power, attitude control, telemetry, and structural support to experimental payloads. Project challenges included integration of attitude control software/hardware, high-output power storage devices, remote communications, high-frequency data collection, structural design, and computer display outputs.

Progressive Failure Analysis Of Composite Panels, Stephen M. Spottswood

Theses and Dissertations

The objective of this research was to determine the physical response, including material failure, of a curved composite panel designed to resist transverse loading. The cause of the material failure, in the form of delamination, fiber and/or matrix failure, was determined through various criterion based on non-linear movement using a finite element analysis technique. Data generated both with and without the addition of progressive failure criteria, was compared with previously published experimental data, noting where the theory diverges from the experimental results. The inclusion of various failure criterion, to include maximum stress, Lee, and Hashin, provided a more realistic representation …

Target Pose Estimation From Radar Data Using Adaptive Networks, Andrew W. Learn

Theses and Dissertations

his research investigates and extends recent work by J.C. Principe at the University of Florida in target pose estimation using adaptive networks. First, Principe's technique is successfully extended to estimate both azimuth and elevation using SAR images. A network trained and tested using MSTAR data yields mean errors of less than six degrees in azimuth and five degrees in elevation. Second, the technique is applied to high-range resolution radar (HRR) signatures. Ground target (azimuth only) testing yields mean errors of less than 11 degrees for most classes. Air target testing for networks trained and tested on the same aircraft class …

Trade-Off Analysis Of Communications Capabilities Of Inter-Satellite Links, Andrew J. Feltman

Theses and Dissertations

This thesis designs, develops, and uses software Graphical User Interfaces (GUIs) to analyze the communications capabilities of Radio Frequency (RF) Inter-Satellite Links (ISLs). The GUIs are geared towards analyzing the proposed ISLs of the Discoverer II program, but are general enough to permit analysis of any free-space RF ISLs. Discoverer II is a demonstration program of low-earth orbiting satellites and is primarily focused on satellite-based sensor technology. This thesis shows RF ISLs can meet the program requirement to broadcast the sensor data back to CONUS in near-real-time. The GUIs operate in real-time and explore trade-offs in the communications capability by …

The Effect Of Registration Errors On Tracking In A Networked Radar System, Bradley J. Mortenson

Theses and Dissertations

To successfully combine information from distributed radar sensors, it is essential that each sensor be correctly referenced in a global coordinate system. If there are biases in the reported position of these sensors, the reported target position will also be biased and the ensuing global estimate of the target position will be degraded. Furthermore, any biases in range or azimuth measurements of these sensors will likewise be reflected in the degradation of global estimate of target position. Registration is the process of ensuring that these errors do not result in the creation of an additional redundant target when only a …

A Climatology-Based Model For Long-Term Prediction Of Radar Beam Refraction, Todd S. Pittman

Theses and Dissertations

The National Air Intelligence Center, WPAFB, OH, needs more accurate predictions of radar beam refraction. A new mode was developed for this thesis replacing the standard atmosphere approach with raytracing and climatology. Usually a microwave radio beam bends towards the earth with a radius of curvature greater than the earth's surface. However, seasonal and climatic variations influence the bending, and at times create temperature or moisture inversions that redirect the energy along the earth's surface leaving radio holes where there is no coverage. This model uses iterative raytracing to determine the most direct path from radar to target through the …

Loop Gain Estimation For Adaptive Control, Jamey P. Sillence

Theses and Dissertations

The identification of a linear discrete-time control system's loop gain is addressed. The classical Kalman filter theory for state estimation in linear control systems is extended, and the control system's loop gain and state are jointly estimated. A rigorous analysis of the measurement situation under consideration yields explicit formulae for the loop gain's unbiased estimate and estimation error's covariance.

Ultra-Wideband Tem Horns, Transient Arrays And Exponential Curves: A Fdtd Look, Troy S. Utton

Theses and Dissertations

This research investigates the possibility of applying exponentially curved conducting plates to single-element Transverse Electromagnetic (TEM) horns and their transient arrays to enhance the UWB characteristics already experienced by these radiators. The first part of this study demonstrates the Finite-Difference Time-Domain (FDTD) method's ability to duplicate experimental data, and establishes the baseline models used throughout the remainder of the research. The baseline models consist of the typical flat-triangle shaped conducting plates. The exponential taper models incorporate the exponential curves in the height, the width, and both the height and width directions. One, two- and four-element baseline configurations are compared to …