Engineering Commons^™

A Recursive Green's Function Method For Boundary Integral Analysis Of Inhomogeneous Domains, Jim D. Freeze, Michael A. Jensen

Faculty Publications

The recursive Green's function method (RGFM) for computation of fields scattered by two-dimensional (2-D) inhomogeneous dielectric bodies is presented. The algorithm efficiently constructs the Green's function for the inhomogeneous region by recursively combining known Green's functions from smaller subdomains. The fields on the scatterer surface are then computed using a boundary integral formulation. Proper implementation of the RGFM results in computational and storage complexities which scale as N1.5 and N, respectively, where N is the total number of discrete cells in a domain. Comparisons of results obtained using the RGFM with those computed from moment method and exact solutions show …

What Can Humor And Advertising Teach Us About Legal Drafting?, Dallin D. Oaks, Jeremy Lewis

Faculty Publications

In his book Legal Drafting in a Nutshell, Haggard includes a useful chapter of nearly 50 pages in which he lists various lexical and structural elements and explains how these can lead to ambiguous writing. The kind of inventory approach that he presents is helpful and reveals that ambiguity doesn't just happen but often results from the careless use of identifiable structures or particular words.

The Evolution Of Probability Functions In An Inelasticly Deforming Two-Phase Medium, Brent L. Adams, H. Garmestani, S. Lin

Faculty Publications

A formulation is introduced here for the evolution of correlation functions in an inelastically deforming two phase medium. Probability functions play a major role in describing the statistical distribution of different phases in a heterogeneous medium in the development of statistical continuum theory. Proper formulation of statistical continuum model for inelastic deformation requires better understanding of the evolution of the corresponding probability functions. A two point probability function representation is used to approximate the statistical correlation functions. The evolution of these functions requires the information from higher order probability functions, in this case, a three point probability function. A decomposition …

Feature Saliency In Artificial Neural Networks With Application To Modeling Workload, Kelly A. Greene

Theses and Dissertations

This dissertation research extends the current knowledge of feature saliency in artificial neural networks (ANN). Feature saliency measures allow for the user to rank order the features based upon the saliency, or relative importance, of the features. Selecting a parsimonious set of salient input features is crucial to the success of any ANN model. In this research, several methodologies were developed using the Signal to Noise Ratio (SNR) Feature Screening Method and its associated SNR Saliency Measure for selecting a parsimonious set of salient features to classify pilot workload in addition to air traffic controller workload. Candidate features were derived …

Three-Dimensional Calculation Of Contaminant Transport In Groundwater At A Dover Afb Site, Tariq O. Hashim

Theses and Dissertations

Macroscale rate-limited sorption modeling was tested using a production transport code, the GMS/FEMWATER ground-water modeling package. The code (Version 1.1 of FEMWATER. dated 1 August 1995) was applied to a 3D conceptual model developed from a field site at Dover AFB, DE. A simulation was performed of a 200 hour contaminant injection pulse followed by clean water flushing. A moment analysis performed on the resulting breakthrough curve validated code self-consistency. Another injection pulse simulation showed that retardation temporally delays the breakthrough peak. Transport simulations of pulsed clean water pumping of the test cell with a prescribed initial contaminant distribution demonstrated …

How To Develop An Interactive Electronic Technical Manual: An Industry Perspective, Ali N. Karabulut, Hilmi Oz

Theses and Dissertations

Improvements in technology, especially in computer science, in the last two decades have made it possible, and preferable to develop digital technical manuals. A digital manual, which is called an Interactive Electronic Technical Manual (IETM), is a package of information required for the diagnosis and maintenance of a weapon systems, optimally arranged and formatted for interactive screen presentation to the end-user. Being the largest organization in the U.S., the Department of Defense has pioneered in the development of IETM concept as well as in the establishment of its standards. There have been many researches done about different IETM applications and …

Development Of An Operations Research Software Package For Army Divisions, Blane C. Wilson

Theses and Dissertations

There exists great potential for applying operations research techniques to solve specific problems in the areas of operations, installation support, and training at the Army division level. Because of the operational tempo of today's active-duty and reserve component units, command must focus on accomplishing the daily missions. Also, due their limited knowledge of the field, planners may not be aware of how operations research can be used to enhance planning and operations. Time, training funds, resources, safety, personnel, and equipment are all critical factors in this process. Operations research techniques could be used to improve division-level operations by saving time, …

Design Of The Computer Subsystem For The Afit Simulation Satellite (Simsat), Michael P. Hanke

Theses and Dissertations

This document details the systematic development of the computer subsystem for the AFIT Simulation Satellite (SIMSAT) from Concept Exploration to Implementation. This subsystem design effort was conducted as part of a larger four-phase team design effort to implement a fully functional, user-friendly test facility to meet current AFIT teaching and research requirements. Once SIMSAT system integration is complete, control laws will execute on the free-floating "satellite" to reduce communication systems overhead and its impact on control law execution, thereby allowing for more robust control system development and execution. Control law development, simulation, and interactive control of the system will occur …

The Conference Proceedings Of The 1998 Air Transport Research Group (Atrg) Of The Wctr Society, Volume 4 , Tae Hoon Oum, Brent D. Bowen, Uno Aviation Institute

Faculty Books and Monographs

UNOAI Report 98-9

The Conference Proceedings Of The 1998 Air Transport Research Group (Atrg) Of The Wctr Society, Volume 1 , Tae Hoon Oum, Brent D. Bowen, Uno Aviation Institute

Faculty Books and Monographs

UNOAI Report 98-6

Powergraf: An Educational Software Package For Power Systems Analysis And Design, Tian Yane, Max Darwin Anderson

Electrical and Computer Engineering Faculty Research & Creative Works

The purpose of PowerGraf is to present a graphical user interface (GUI) and a convenient tool for building one-line diagrams displaying data. The GUI is open and friendly for power systems design, analysis and control, because a picture provides a better illustration of cause-and-effect relationships than a tabular printout does. Basic elements such as buses, lines and transformers are given such that the power system topology is easily drawn with this tool, and the system parameters are entered on the picture and checked visually. This enables the power system topology and the system data to be shown on one picture …

The Conference Proceedings Of The 1998 Air Transport Research Group (Atrg) Of The Wctr Society, Volume 3 , Tae Hoon Oum, Brent D. Bowen, Uno Aviation Institute

Faculty Books and Monographs

UNOAI Report 98-8

Determination Of The Tensile And Shear Strengths Of Screws And The Effect Of Screw Patterns On Cold-Formed Steel Connections, Marc Allen Sokol, Roger A. Laboube, Wei-Wen Yu

CCFSS Library (1939 - present)

PREFACE This report summarizes two studies related to the design of cold-formed steel connections. The study topics included the creation of a test standard for determining the strength of a screw, and the determination of the strength of a screw connection. A standard test protocol does not exist for determining the strength of a screw. Today, manufacturers use test protocols developed for their products. Thus, there is no consistency in defining the structural performance of a screw. A test standard has been developed. The standard used as its model the American Society of Testing and Material's F 606, Standard Test …

Study On The Estimation And Control Of A Liquid Composite Molding Process, Dennis Sourlas, Susmito Naha, Gary Patterson, Richard Parnas

Chemical and Biochemical Engineering Faculty Research & Creative Works

An on-line nonlinear receding horizon control algortithm is employed in order to achieve setpoint tracking targets in the context of liquid composite molding processes. The robustness of this control strategy against process-model deviations is tested. Finally, recursive parameter estimation is employed as a means of actively enhancing the performance of the process control algorithm. © 1998 AACC.

An Analysis Of Texture Resulting From Thermomechanical Processing Of Ti-6al-V, David J. Brock

Masters Theses

An investigation of texture and microstructure formation in Ti-6Al-4V after thermomechanical processing and heat treating was performed. X-ray diffraction was used to measure prismatic and pyramidal pole figures. These pole figures were used to calculate basal pole figures, which showed significant changes in texture from heavy rolling and near or above β-transus heat treatments. Primary texture components were found to be strengthened by near β-transus heat treatments. For heavily rolled material, above β-transus heat treatments were found to reverse the primary texture components order of dominants. Heavy rolling was found to reduce the RD component and strengthen the TD.

Evaluation Of Reference Markers, Jerry G. Pigman

Kentucky Transportation Center Research Report

The objective of this research evaluation was to evaluate the reference markers which were installed on sections of interstates and freeways in the Cincinnati-northern Kentucky area, the Lexington-Fayette Urban County area, the Louisville-southern Indiana area, and the Indianapolis area. The evaluation was conducted to determine if the use of reference markers at spacings of 0.1 or 0.2-mile intervals could improve the effectiveness of the emergency response and incident management processes. Also evaluated were color of the markers and the placement location within the right-of-way. Both "'white on blue" and ''white on green" markers were installed on various projects, with some …

An Image Model Based On Occluding Object Images And Maximum Entropy, John A. Stuller, Rahul Shah

Electrical and Computer Engineering Faculty Research & Creative Works

This Paper Introduces a Statistical Image Model based on Occlusion and Maximum Entropy. the Statistical Model Combines a Fundamental Property of Image Formation, Occlusion, with Both Object-Image Shape and Nonuniform Object-Image Intensity. the Model is a Composition of Individual Object-Images that Have Random Positions, Shapes, and Intensities, and that Occlude Both Background and One Another. We Derive the Autocorrelation and Second-Order Probability Density Functions of This Model and Give Several Examples. © 1998 IEEE.

Registration Violations And The Use Of Optical Character Recognition Technology At Kentucky Weigh Stations, Jennifer R. Walton, Joseph D. Crabtree

Kentucky Transportation Center Research Report

As a Model Deployment State for CVISN (Commercial Vehicle Information Systems and Networks), Kentucky is valuating and improving its procedures related to commercial vehicle administration and enforcement. As part of this effort, the Kentucky Transportation Center (KTC) was asked to investigate the frequency of registration-related violations at Kentucky weigh stations and the potential effectiveness of a license plate recognition (LPR) system in detecting and deterring such violations. Typical violations considered in the investigation included using an expired license plate, hauling weight in excess of the truck’s registered weight, or traveling in Kentucky without proper authority.

KTC researchers first examined Kentucky’s …

Probabilistic Life Cycle Cost Analysis Fhwa Demonstration Project Dp 115, R. Clark Graves, David L. Allen

Kentucky Transportation Center Research Report

Kentucky has been involved in several projects relating to the development of a Life Cycle Cost (LCC) analysis procedures of pavement structures. Research projects have been conducted by the Kentucky Transportation Center dealing with development of a more robust LCC procedures for pavement analysis. A research project has also been conducted developing network level LCC procedures. These procedures are currently in the evaluation phase and have not been implemented into current Kentucky Transportation Cabinet procedures. Life Cycle Costs analysis is utilized on various projects throughout Kentucky to evaluate various pavement construction and rehabilitation alternatives.

This report will outline the current …

Seismic Evaluation Of The Ohio River Bridge On Us51 At Wickliffe, Kentucky, Issam E. Harik, Chelliah Madasamy, Denglin Chen, Leonong Zhou, Kevin Sutterer, Ron Street, David L. Allen

Kentucky Transportation Center Research Report

This report presents the of seismic evaluation of the Ohio river bridge on US51 at Wickliffe, Kentucky. The main bridge is a five-span single-deck cantilever through-truss type. The approach bridge has 21 spans on the Kentucky side and 6 spans on the Illinois side. Although this bridge has not yet been subjected to a moderate or major earthquake, it is situated within the influence of the New Madrid seismic zone.

The seismic evaluation program consists of field testing and seismic response analysis. The modal properties of the main bridge are determined through field testing, and are used to calibrate the …

Evaluation Of 93-Inch Corrugated Metal Culvert On Ky 693 And Us 23, Green-Up County, L. John Fleckenstein, Richard Reitenour, David L. Allen

Kentucky Transportation Center Research Report

No abstract provided.

Adaptive Channel Equalization Techniques, Saied Razavilar

Masters Theses

Inter Symbol Interference (ISI) is a characteristic of band-limited communication channels that can severely degrade the digital communication system performance if not treated properly. Channel equalization techniques may be used to mitigate the effects of ISI in the system, thereby improving the system capacity and performance. In this thesis, the problem of Inter Symbol Interference caused by the nonlinear characteristics of band limited communication channels and adaptive equalization techniques to combat the effects of ISI are discussed. First, the analysis of ISI in a band limited communication channel using a concrete theoretical framework is presented. Next, various adaptive equalization techniques …

Bs News

Building Services Engineering

No abstract provided.

Fitness Landscape Analysis Of Discrete Constrained Optimization Problems, Sai Prasanna Ravichandran

Masters Theses

The exponentially large size of the solution space of typical optimization problems precludes the use of any deterministic approach to search for an optimal solution. A more efficient and efficacious approach is to use heuristic algorithms based on rules of thumb to guide the search process in the solution space. Associated with every solution in the space is a real number called fitness that signifies the quality of a solution. This space and the fitness values together form the fitness landscapes. Knowledge about the topology of these fitness landscapes is vital for any heuristic search operator to expedite the search …

An Analysis Of Drafting Competencies In Iowa's High Schools, Rodrick A. Thompson

Graduate Research Papers

Teachers in Iowa high schools are expected to have students achieve the competencies identified by the State of Iowa Department of Education. The competencies for Iowa high school engineering-related classes were published in 1991. They were compiled as a result of Senate File 449. Industry leaders, as well as teachers, throughout the state of Iowa who were actively utilizing drafting skills in 1991 helped create the outcome competencies. Since that time, these competencies have not been reviewed or revised and may need updating. The demands of industry change so frequently it is possible these are no longer the appropriate competencies. …

The Effect Of Suspended Particles On The Corrosion Resistance Of Electrodeposited Zinc Powders, Qing-Wen Li, Qing Yang, Xi Xia

Journal of Electrochemistry

Zinc powders were electrodeposited from ZnCl₂ baths with containing suspension of unsoluble particles such as graphite, PbO₂, SnO₂, TiO₂, SiO₂ etc.. The structure, morphology and corrosion behavior of zinc powder were analyzed. SEM results showed that the dendritic growth of zinc can be inhibited by applying the suspension method. Suspension of PbO₂, SnO₂, TiO₂, SiO₂ and In₂O₃ could greatly improve the corrosion protection of zinc powder in 5 mol/L KOH. In addition, fractal theory is employed to further explain the results

Primary Research Of Reversible Proton Exchange Membrane Regenerative Fuel Cells, Zhi-Gang Shao, Bao-Lian Yi, Ming Han

Journal of Electrochemistry

In this paper, we report the results of our studies on regenerative proton exchange membrane fuel cell (RPEMRFC) catalysts, electrode preparation and their performances. The Pt catalyst for the oxygen electrode was replaced by 60 w%Pt + 40 w%IrO₂ which reduces polarization by 0.2 V in a polymer protone exchange membrane fuel cell. The cycle performance of RPEMRFC was found to be manly effected by the stability of the diffiusion layer of bifunctional oxygen electrode.

The Latest World Wide Progress In Solid Oxide Fuel Cell, Yi Jiang

Journal of Electrochemistry

Solid oxide fuel cell (SOFC) is a novel, green electricity generation technology, which has been showing rapid development since 1980's. In light of its high efficiency, environmental friendly, fuel adaptability and long term stability, the Research, Development and Demonstration (RD&D) of this hype of full cell have been emphasized in a large number of developed countries. Based on the information communicated at the latest symposium on SOFC held last year in Aachen (Germany) and the knowledge gained through years of research in this field, a comprehensive review on the latest development of the tubular, this planar SOFC as well as …

A Preliminary Study Of The Synthesis Of Tin-Based Amorphous Material And Its Behavior On Lithium Intercalation, Li Liu, Han-Xi Yang, Ju-Tang Sun, Xing-Ping Ai

Journal of Electrochemistry

An amorphous lithium inserting anode material based on Tin oxide glass was synthesized by salification in solution and its properties on lithium intercalation was investigated by X ray diffraction (XRD), microelectrode voltammetry and charge discharge measurements. The results have shown that this kind of material has considerable electrochemical reversibility toward lithium intercalation deintercalation. The available discharge capacity of the material reaches 430 mAh/g with charge-discharge efficiency over 90%, showing a great potential for practical use.

Studies Of Spinal Li(1+X)Mn(2-X)O4 Rechargeable Lithium Ion Battery, Xiao-Mei Wu, Qing-He Yang, Zhong-Kao Jin, Hao-Qing Wu, Xiang-Fu Zong

Journal of Electrochemistry

The spinel Li intercalation compound Li_1+xMn_2-xO₄ (0< x <1) was prepared by using techniques of cyclic voltammetry. The electrochemical parameters of Li_1+xMn_2-xO₄ electrode vary as either the starting materials or the synthesis temperature changes. It was found that the initial capacity and reversible behaviors of the Li_1+xMn_2-xO₄ electrode depends on the amount of the excess Li, represented as x in Li_1+xMn_2-xO₄. The reversible of Li intercalation process for Li_1+xMn_2-xO₄ electrode was demonstrate by cyclic voltammograms.