Engineering Commons^™

A Performance Analysis Of Dynamic Routing Algorithms In An Iridium-Like Low Earth Orbit Satellite System, Stephen R. Pratt

Theses and Dissertations

This research presents a first of its kind comparative analysis of the Extended Bellman-Ford and Darting algorithms, using the Iridium low earth orbit (LEO) satellite system configuration for the simulation environment. The algorithms are compared to one another via discrete-event computer simulation and evaluated based on their ability to route real-time voice communications under low, medium, and high network loading conditions. The algorithms' ability to meet real-time voice constraints is evaluated with a full and degraded satellite constellation using an algorithmic satellite removal method. The investigation results indicate that both algorithms are suitable for use in a LEO environment and …

Incorporating Scene Mosaics As Visual Indexes Into Uav Video Imagery Databases, Timothy I. Page

Theses and Dissertations

The rise of large digital video archives has strengthened the need for more efficient ways of indexing video files an accessing the information contained in them. Reconnaissance platforms, such as the Predator UAV, are contributing thousands of hours of video footage that require analysis, storage, and retrieval. A process is proposed for converting a video stream into a series of mosaic and selected still images that provide complete coverage of the original video. The video mosaic images can be utilized as visual indexes into a video database. In addition, mosaic images contain information from an entire sequence of video frames …

Asymmetric Load Balancing On A Heterogeneous Cluster Of Pcs, Christopher A. Bohn

Theses and Dissertations

In recent years, high performance computing with commodity clusters of personal computers has become an active area of research. Many organizations build them because they need the computational speedup provided by parallel processing but cannot afford to purchase a supercomputer. With commercial supercomputers and homogenous clusters of PCs, applications that can be statically load balanced are done so by assigning equal tasks to each processor. With heterogeneous clusters, the system designers have the option of quickly adding newer hardware that is more powerful than the existing hardware. When this is done, the assignment of equal tasks to each processor results …

Te Scattering From Bubbles In Ram, John G. Cochran

Theses and Dissertations

This research looks at various bubble sizes in one particular magnetic RAM (MAURAM) type, from grazing incidence (00) to 450 and at a frequency range from 2-18 GHz, TE polarization. The results from the absolute RCS measurement of the various sized RAM bubbles are discussed in terms of a frequency dependent increase in RCS. In the frequency band of interest, 2-18GHz, a RAM bubble increases the RCS at all angles, from grazing incidence (00) to 450. From 10-18GHz the RAM bubble does not cause an increase in RCS. In general the highest RCS is at 2GHz and tapers down as …

An Empirical Prediction Model Of The Performance Impacts Of Material Tolerances In Frequency Selective Surfaces Using The Monte Carlo Method, Matthew D. Craig

Theses and Dissertations

Standard computational tools predicting frequency selective surface (FSS) performance model periodic structures as an infinite-by-infinite array of perfectly placed elements with perfect, identical dimensions, and with dielectric layers of uniform thickness and material composition. These models do not address perturbations caused by manufacturing tolerances of elements and dielectric layers, nor do they address edge effects caused by finite-by-finite dimensional arrays. The Monte Carlo Method was used to determine the effects of random variations in element dimension, placement, dielectric thickness, and dielectric material on FSS performance. A full-factorial experimental design was applied, and eight hundred twenty-five unique finite arrays of elements …

Optimal Wavelet Denoising For High Range Resolution Radar Classification, Brian M. Huether

Theses and Dissertations

Noncooperative identification (NCTI) of airborne targets is a top priority for the Air Force and this thesis makes a significant contribution to that area. High range resolution radar (HRR) provides an attractive means to perform NCTI. When measured HRR data is used, classification performance is excellent. However, it is often not feasible to acquire measured HRR signatures for a wide set of targets, thus necessitating the use of synthetically generated HRR data. Classification performance suffers severe degradation when using synthetic data. This thesis suggests that a large portion of HRR signature content is non-discriminatory and that this content is a …

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 …

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.

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 …

Bs News

Building Services Engineering

No abstract provided.

Closure To "Irrigation Performance Measures: Efficiency And Uniformity", Albert J. Clemmens, Charles M. Burt, Kenneth H. Solomon, Terry A. Howell, Theodor S. Strelkoff

BioResource and Agricultural Engineering

No abstract provided.

Monotonic And Cyclic Tests Of Long Steel-Frame Shear Walls With Openings, Alexander J. Salenikovich, J. Daniel Dolan, W. Samuel Easterling

American Iron and Steel Institute (AISI) Specifications, Standards, Manuals and Research Reports (1946 - present)

No abstract provided.

Combustion Properties Of Biomass, B. M. Jenkins, Larry Lin Baxter 8507091, T. R. Miles Jr, T. R. Miles

Faculty Publications

Properties of biomass relevant to combustion are briefly reviewed. The compositions of biomass among fuel types are variable, especially with respect to inorganic constituents important to the critical problems of fouling and slagging. Alkali and alkaline earth metals, in combination with other fuel elements such as silica and sulfur, and facilitated by the presence of chlorine, are responsible for many undesirable reactions in combustion furnaces and power boilers. Reductions in the concentrations of alkali metals and chlorine, created by leaching the elements from the fuel with water, yield remarkable improvements in ash fusion temperatures and confirm much of what is …

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.

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 …

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 …

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 …

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 …

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.

Space Maneuver Vehicle Orbital Mission Planner: Development Of Application And Analysis Of On-Demand Maneuvering Ability, Shon P. Williams

Theses and Dissertations

The USAF has developed the Space Maneuver Vehicle (SMV) to fulfill the requirement for flexibility, rapid response, and on-demand maneuverability of space assets. This reusable satellite merges the efficiency and readiness of aircraft-like operations with the capability of global coverage from space. Designed to provide over 10,500 fps of velocity change (or delta-v) while in orbit, the SMV out-maneuvers existing satellites by up to 100 times. This thesis helps transition the SMV to the operational area by demonstrating their responsiveness to varied mission taskings. The SMV Orbital Mission Planner allows the operator to place any number of SMVs in orbit …

Whole Spacecraft Vibration Isolation, Gregory G. Karahalis

Theses and Dissertations

The Department of Defense identified launch vibration isolation as a major research interest. Reducing the loads a satellite experiences during launch will greatly enhance the reliability, lifetime, and payload to structure ratio. DoD satellite programs stand to benefit significantly from advances in vibration isolation technology.

Heat Transfer To The Inclined Trailing Wall Of An Open Cavity, Orval A. Powell

Theses and Dissertations

Experimental and computational heat transfer investigations were performed on a cavity with an inclined trailing wall (20-degrees to the horizontal), simulating one under investigation for use in a scramjet engine. Heat transfer data are reported in the form of Stanton number obtained using a curve fit to the recorded transient surface temperature history under cold flow conditions. Ascending from the reattachment point, the Stanton number increased by nearly 50% due to flow compression. This effect of flow compression was also evident at the junction of the cavity floor and inclined trailing wall, where the Stanton number also increased by 50%. …

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) …

Biodegradation Of Aircraft Deicing Fluid Components In Soil, Baron W. Burke

Theses and Dissertations

Aircraft de-icing fluids (ADFs) are used worldwide to ensure safe aircraft operations. This research effort was conducted to analyze the biodegradation effects of two chemical components of ADFs, propylene glycol (PG) and tolyltriazole (TTA), in a high-clay soil. The research used four test methods; automated respirometry, high performance liquid chromatography (HPLC), microbial colony population counts (MCPC), and agar well diffusion tests (AWDT). The research was partitioned into two phases of investigation. Phase-one analyzed individual and combined ADF chemical components on uncontaminated soil. The presence of TTA, from 25 - 1,000 mg/kg, reduced the maximum respiration rate of 1,000 mg/kg PG …

Textual Analysis Of Environmental Compliance Assessment Program Findings, Arthur L. Gepner Jr.

Theses and Dissertations

The United States Air Force (USAF) is committed to assessing environmental compliance; this is achieved in the USAF through the Environmental Compliance Assessment Management Program (ECAMP). These ECAMP audits are designed strictly to assess compliance performance at one point-in-time. They are not intended to assess underlying environmental management systems. This study provides insight into the USAF Environmental Management System (EMS) through a textual analysis of ECAMP data. The analysis discovers eleven categories that emerged from the data: performance, communication, documentation, coordination, training, guidance, notification, resource, human resource, material resource, and financial resource. These categories display a hierarchical relationship. This hierarchical …

The Determinants Of Locational Choice For Air Force Military Renters: Implications For Policy, Eldrick L. Hill

Theses and Dissertations

Housing allowances and military family housing make up approximately $7 billion dollars of the budget for the Department of Defense (DoD). The military uses a Housing Market Analysis (HMA) to determine rental housing availability around its installations. This thesis describes and analyzes the locational choices of military renters. This thesis examines 16 bases in the continental U.S. using military and census data. It is concluded that the locational preferences of military renters vary inversely with distance from their duty location and this needs to be accounted for when assessing the availability of military rental housing. The implications of military renter …

Optimal Pulsed Pumping Schedule Using Calculus Of Variation Methodology, Tay W. Johannes

Theses and Dissertations

Application of a variational optimization technique has demonstrated the potential strength of pulsed pumping operations for use at existing pump-and-treat aquifer remediation sites. The optimized pulsed pumping technique has exhibited notable improvements in operational effectiveness over continuous pumping. The optimized pulsed pumping technique has also exhibited an advantage over uniform time intervals for pumping and resting cycles. The most important finding supports the potential for managing and improving pumping operations in the absence of complete knowledge of plume characteristics. An objective functional was selected to minimize mass of water removed and minimize the non-essential mass of contaminant removed. General forms …

Expeditious Methods For Site Characterization And Risk Assessment At Department Of Defense Hazardous Waste Sites In The Republic Of Korea, Dean H. Hartman

Theses and Dissertations

The overall goal of this research was to provide Department of Defense (DoD) decision-makers in the Republic of Korea (ROK) with preferred innovative site characterization technologies and risk assessment methods to meet their needs in obtaining hazardous waste site data and then prioritizing those sites for remediation based upon risk. The study examined the following: primary sources and types of existing contamination at DoD installations in the ROK; available site characterization data; criteria to be used in selecting innovative site characterization technologies; costs and capabilities of the innovative site characterization technologies; risk assessment or risk-based corrective action (RBCA) methods available …

Environmental Management Strategies In Public Sector Organizations, Charles P. Roberts

Theses and Dissertations

Environmental management research investigates environmental and ecological practices in organizations. Environmental strategy models or typologies are developed to classify organizations according to their environmental and ecological practices. Past research for environmental management strategy has focused on the profit sector versus the public sector. Drivers such as market and financial forces may not be as evident in the public sector as they are in the profit sector. This research explored environmental management strategies in public sector organizations. An environmental management strategy typology was developed to investigate the structural aspects of organizations. The typology and respective instruments were used in a case …

Concept Design And Optimization Of Msw Management System, James R. Palmer

Theses and Dissertations

The maximum recovery of recyclables from municipal solid waste (MSW) using material recovery facility (MRF) technologies is determined. Two waste streams at Spangdahlem AB, Germany are analyzed; stationary container wastes and commingled recyclables. Three schemes are considered, one for each waste stream, and one for both. Multi-criteria decision making is the methodology. The criteria are recovery and annual benefit minus cost (B-C). Recovery is determined using the recovery factor transfer function of Diaz et al. (1982). Each technology, or unit operation, in a sequence is independent because particle size distribution of each waste component is considered. B-C is based on …