Engineering Commons^™

Characterization Of A Resistive Half Plane Over A Resistive Sheet, John R. Natzke, John L. Volakis

Faculty Publications - Department of Electrical Engineering and Computer Science

The diffraction of a resistive half plane over a planar resistive sheet under plane wave illum1ination is determined via the dual integral equation method (a variation of the Wiener-Hopf method). The solution is obtained upon splitting the associated Wiener-Hopf functions via a numerically efficient routine. Based on the derived exact half plane dliffraction coefficient, a simplified equivalent model of the structure is developed when the separation of the half plane and resistive plane is on the order of a tenth of a wavelength or less. The model preserves the geometrical optics field of the original structure for all angles and …

Electric Fields Of An H-Plane Tapered Iris, John R. Natzke, T. Koryu Ishii

Faculty Publications - Department of Electrical Engineering and Computer Science

Microwave electric fields of an X -band H -plane tapered iris are calculated and plotted using the moment method for the first time. The moment method results are compared with previously obtained experimental measurements and numerical results based on an equivalent circuit approach, giving confirmation that the tapered iris is both a reciprocal and asymmetrical network. The moment method results now reveal that the asymmetry stems from the asymmetry in the phase of the input and output voltage reflection coefficients, their magnitudes being equal.

Electronic Simulation Of The Temporal Characteristics Of Photon Memory Echoes And Some Related Applications, Yuwen Kuo, Monish Ranjan Chatterjee

Electrical and Computer Engineering Faculty Publications

The characteristics of nonlinear photon memory echoes are investigated by means of SPICE simulations using equivalent resonator ensembles. By developing implicit nonlinear circuit models in the memory echo domain, the triple product formalism of electronic holography, involving correlation and convolution, is tested for the storage and recall of arbitrary signals and/or data bit streams in both time-inverted and nontime-inverted modes. Furthermore, a few specific optical data processing applications are also simulated in which the mixed binary multiplication of two or more binary bit streams is achieved.

Higher order products, optical pattern recognition, and other possible applications are also discussed. It …

Ccfss News August 1993, Wei-Wen Yu Center For Cold-Formed Steel Structures

CCFSS Newsletters (1999 - 2008)

No abstract provided.

Laboratory Testing Of The Reflectance Properties Of Roofing Materials, Florida Solar Energy Center, Danny Parker

FSEC Energy Research Center®

Past simulation and test cell studies have shown potential reduction to building cooling loads from higher exterior surface solar reflectances (Givoni and Hoffman, 1968; Givoni, 1976; Chuan and Busching, 1983; Griggs and Shipp, 1988; Anderson, 1989; Akbari et al., 1990; Chandra and Moalla, 1991; Bansal et al., 1992). Furthermore, simulation analysis of macro-climatic effects have shown that light colored surfaces may reduce the magnitude of the urban heat island (Taha et al., 1988; Akbari et al, 1989; Akbari et al., 1992).

Figure 1 shows a graphic illustration of the potential influence of surface reflectance on roof solar heat gain. The …

Incorporation Of Traffic Collision Alert System (Tcas) Advisories On Heads-Up Displays: Enhanced Pilot Response, Hamadeh A. Nureddine

Master's Theses - Daytona Beach

This study evaluated the effects that heads-up mounted TCAS displays had on pilot response and workload. Pilot response was evaluated by: (a) response time to a traffic advisory, and (b) number of missed traffic alerts. Workload assessment was accomplished in accordance with NASA's Task Load Index (TLX). Subjects were all licensed pilots with a minimum of a private pilot license and an instrument rating. A total of 32 subjects were randomly assigned to experimental and control groups utilizing HUD-mounted, and conventional, TCAS displays respectively. Performance data was collected during computer-simulated flights, while subjective workload levels were reported at the end. …

An Econometric Analysis Of The Nw/Klm Corporate Alliance, S. Koo Boon

Master's Theses - Daytona Beach

This thesis investigates whether a corporate alliance between international air carriers is beneficial, considering the changes in the global air transport system. Dividing the research method into three phases, the author first lists and identifies the recent changes in world air transport trends. Then, the author defines the different types of alliances and studies the advantages and disadvantages of these corporate alliances. Finally, a multiple regression analysis is performed using the KLM/Northwest Airlines alliance as a case analysis.

An Energy Approach To Seismic Analysis And Design Of Secondary System, Genda Chen, Tsuteh Soong

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

The dynamic analysis and design of secondary systems have been extensively studied over the last two decades, resulting in a better understanding of their general dynamic characteristics. One of the current challenges for researchers is to develop simple yet accurate procedures incorporating these research results and transfer them into the development of practical design and performance evaluation procedures. This is the basic thrust of this report.

Statistical energy analysis has been proven to be a powerful tool in the dynamic analysis of complex systems involving interaction effect between acoustic field and structure. In this report, such a tool is systematically …

Economic Analysis Of Costs Incurred From Chemical Exposures In The Workplace Resulting In Non-Carcinogenic Responses As Additional Justification For Pollution Prevention Projects, Michael L. Forcht, Timothy D. Neu

Theses and Dissertations

This research determines the applicability of using costs associated with chemical exposures in the workplace for financial justification of pollution prevention projects. Specifically, this thesis looks at costs incurred due to noncarcinogenic effects caused by chemical exposures. Average costs are determined through researching applicable statistical cost data. Acute effects are analyzed using an analysis of available statistical accident data from multiple sources. Expected values are then calculated based upon the projected cost of an accident and the probability of having an accident. Chronic effects are analyzed using an empirical analysis. A risk assessment is used to determine the likelihood of …

Seismic Analysis Of The Brent-Spence Bridge, Issam E. Harik, David L. Allen, Ronald L. Street, Meiwan Guo, R. Clark Graves, Jack A. Harison, Mark J. Gawry

Kentucky Transportation Center Research Report

This report presents the findings of a seismic evaluation of the Brent-Spence bridge. The bridge is a double-deck cantilever through truss which was constructed in 1961; it is a critical highway link conveying 1-75 over the Ohio river. While not yet subjected to a moderate or major earthquake, the bridge is within the influence of the New Madrid, Wabash Valley, and Anna seismic zones.

The seismic evaluation program consisted of field testing and seismic analysis. The vibrational properties of the main bridge were determined through field testing and used to calibrate a 3-D finite element model. The model was then …

Proposed Smoothing Technique To Avoid Numerical Instabilities In A Hydrodynamic Numerical Model, Thomas P. Abraham

Electronic Theses and Dissertations

Despite every effort being made to produce a completely problem-free computational model, no breakthrough has yet been made. When a numerical model is used to solve a real world problem, there is a tendency for the non-physical spurious waves to creep in. If these waves are not checked, they can lead to serious instability problems. Once these waves are removed, the model should be able to simulate physical phenomenon like circulation, separation, flow reversal in the vertical plane, mixing/transport, convection/diffusion, etc.

When a numerical mode] is made to run for a certain period of time, node-to-node oscillations may arise and …

A Study Of Numerically Efficient Algorithms For Power System Dynamic Analysis, J. G. Chen, Mariesa Crow

Electrical and Computer Engineering Faculty Research & Creative Works

In this paper, the multirate method is introduced to analyze power system behavior including linear and nonlinear systems with widely varying time constants. The development and study of time domain simulation techniques and error detection are discussed. The results, both in terms of accuracy and computation time, are compared to traditional simulation methods in a small nonlinear power system example

An Algorithm For Automated Printed Circuit Board Layout And Routing Evaluation, Todd H. Hubing, Thomas Van Doren, James L. Drewniak, Puneet Grover, R. Lee Hill

Electrical and Computer Engineering Faculty Research & Creative Works

An algorithm has been developed to evaluate printed circuit boards that are designed using automated board layout and routing software. The algorithm analyzes aspects of component placement and trace routing while searching for violations of basic EMC design principles. The algorithm is implemented in code designed to work with a widely used board layout and routing program. This code can help novice and experienced circuit board designers to avoid mistakes that may result in serious electromagnetic compatibility problems.

Analysis Of Sandwich Plates Subjected To Blast Loading, Vijay Prasad Bulla

Masters Theses

A dynamic analysis is presented for the bending response of square sandwich plates with isotropic core and facings under blast type pressure. The maximum central deflections of simply supported plates under static and dynamic loadings are compared for various thicknesses and elastic moduli. The deviation of the thick sandwich plate results from the pure-bending theory results is presented for various core properties. Small deflection dynamic iso-response plots are shown for different core rigidities. To study the limits of small deformation linearity for various sandwich plates, non-linear results for deformations under high pressure loads are compared with the linear results. The …

Internal Stress Wave Measurements In Solids Subjected To Lithotripter Pulses, S. M. Gracewski, G. Dahake, Z. Ding, S. J. Burns, E. Carr Everbach

Engineering Faculty Works

Semiconductor strain gauges were used to measure the internal strain along the axes of spherical and disk plaster specimens when subjected to lithotripter shock pulses. The pulses were produced by one of two lithotripters. The first source generates spherically diverging shock waves of peak pressure approximately 1 MPa at the surface of the specimen. For this source, the incident and first reflected pressure (P) waves in both sphere and disk specimens were identified. In addition, waves reflected by the disk circumference were found to contribute significantly to the strain fields along the disk axis. Experimental results compared favorably to a …

Tillage And Cropping Practice Effects On Furrow Irrigation: Hydraulics And Macroporosity, Martin John Norton

Department of Agricultural and Biological Systems Engineering: Dissertations, Theses, and Student Research

Furrow irrigation efficiency and performance is greatly influenced by advance time, infiltration and roughness. An experiment was conducted to determine tillage system and cropping system effects on those three variables. Four tillage systems, disk (D), chisel and disk (C), ridge till (RT), and slot plant (SP) were the treatments. They had been continuous for 17 years on a Hasting's silt loam (fine, montmorillonitic, mesic Udic Argistoll) soil. Subtreatments were a corn/soybean rotation (CS) and a continuous corn (CC) cropping system since 1984. A complete block split plot design was used. We measured inflow rate, advance time, runoff, and furrow geometry …

A Study Of Effects Of Flotation Conditions On Flotation Efficiency And Fiber Loss, Wiwat Walaipachara

Masters Theses

Three variables: (1) consistency, (2) agitation, and (3) bubble size were studied for their effects on flotation efficiency and fiber loss. Flotation was done by using a Hallimond apparatus. The floated and non-floated portions were quantified by image analysis based on number of ink particles and total area of ink. The percent fiber loss was calculated from solids' weights of both portions. The floated part was analyzed by a KAJAANI instrument for fiber length average and distribution.

The results showed that flotation efficiency increased with agitation but decreased with increasing consistency. Fiber loss increased with consistency but decreased with increasing …

Flowable Fill, Herpicc

Indiana Local Technical Assistance Program (LTAP) Technical Reports

This publication supplies information on Controlled Low Strength Material (CLSM) and performance related to material characteristics and mixture properties.

Excited Atomic Bromine Energy Transfer And Quenching Mechanisms, Ray O. Johnson

Theses and Dissertations

Pulsed and steady-state photolysis experiments have been conducted to determine the rate coefficients for collisional deactivation of the spin-orbit excited state of atomic bromine, Br(²p_1/2). Pulsed lifetime studies for quenching by Br₂ and CO₂, established absolute rate coefficients at room temperature of k_Br2 = 1.2 ± 0.1 x 10^-12 and k_CO2 = 1.5 ± 0.2 x 10^-11 cm³/molecule-s. Steady-state photolysis methods were used to determine the quenching rates for the rare gases, N₂, 0₂, H₂, D₂, NO, …

Rolling Friction Research Instrument, John P. Ward

Masters Theses

An instrument has been analyzed, designed and constructed that will accurately measure the rolling resistance of metallic spheres an plane surfaces subjected to normal loading which will produce contact stresses approaching material yield.

Networking Your Cd-Roms: A Texas Tale, Margaret Sylvia

Faculty Publications

Installation of a CD-ROM network at St. Mary's University Academic Library created a revolution in the way students and faculty do research.

Effect Of Reduced Plate Width On The Structural Behaviour Of A Triangularly Folded Plate Barrel Vault, S Manyele

Tanzania Journal of Engineering and Technology (TJET)

Various methods of analysis have been employed to predict the  structural behaviour of the Triangularly Folded Plate Barrel  Vault, with conflicting results. A review of past analytical  and experimental investigations carried out on the structure  show that theoretical analysis based on a smaller effective  width rather than the overall plate width is capable of closely  predicting the deflection behaviour of the structure.  This paper presents an experimental study of the behaviour of  a triangularly folded plate barrel vault with physically reduced  plate width.  It is found that physical reduction of the plate width to  correspond to ‘theoretical’ effective width weakens …

35th Rocky Mountain Conference On Analytical Chemistry

Rocky Mountain Conference on Magnetic Resonance

Program, abstracts, and information about the 35th annual meeting of the Rocky Mountain Conference on Analytical Chemistry, co-sponsored by the Colorado Section of the American Chemical Society and the Rocky Mountain Section of the Society for Applied Spectroscopy. Held in Denver, Colorado, July 25-29, 1993.

Automatic Tuning Of Integrated Filters Using Neural Networks, Lutz Henning Lenz

Dissertations and Theses

Component values of integrated filters vary considerably due to· manufacturing tolerances and environmental changes. Thus it is of major importance that the components of an integrated filter be electronically tunable. The method explored in this thesis is the transconductance-C-method.

A method of realizing higher-order filters is to use a cascade structure of second-order filters. In this context, a method of tuning second-order filters becomes important.

The research objective of this thesis is to determine if the Neural Network methodology can be used to facilitate the filter tuning process for a second-order filter (realized via the transconductance-C-method). Since this thesis is, …

Unified Bias Analysis Of Subspace-Based Doa Estimation Algorithms, Yang Lu

Dissertations and Theses

This thesis presents the unified bias analysis of subspace-based DOA estimation algorithms in terms of physical parameters such as source separation, signal coherence, number of senors and snapshots. The analysis reveals the direct relationship between the performance of the DOA algorithms and signal measurement conditions. Insights into different algorithms are provided. Based upon previous first-order subspace perturbations, second-order subspace perturbations are developed which provide basis for bias analysis and unification. Simulations verifying the theoretical bias analysis are presented.

Robust Linear Quadratic Regulation Using Neural Network, Kisuck Yoo, Michael Thursby

Electrical Engineering and Computer Science Faculty Publications

Using an Artificial Neural Network (ANN) trained with the Least Mean Square (LMS) algorithm we have designed a robust linear quadratic regulator for a range of plant uncertainty. Since there is a trade-off between performance and robustness in the conventional design techniques, we propose a design technique to provide the best mix of robustness and performance. Our approach is to provide different control strategies for different levels of uncertainty. We describe how to measure these uncertainties. We will compare our multiple strategies results with those of conventional techniques e.g. H∞ control theory. A Lyapunov equation is used to define stability …

Gis Utilization For Analysis Of District Drainage Water Recycling, Charles M. Burt, Robert E. Walker

BioResource and Agricultural Engineering

An ARC-INFO GIS system was used to identify physical drainage facilities in a 32,000 ha area of the San Joaquin Valley of California. Once the drainage facilities and linkages were established, it was possible to characterize the strategies used by various irrigation districts to control drainage outflows to the San Joaquin River. The motivation behind the study was the reduction of salt and selenium flows, via agricultural drainage, into the River.

Optimal Contaminant Plume Management With Us/Wells, Alaa H. Aly, Richard C. Peralta

Civil and Environmental Engineering Faculty Publications

A micro-computer based software package developed at utah State University for computing optimal pumping strategies for well systems (US/WELLS) is demonstrated. US/WELLS is used to determine the optimal time-varying sequence of extraction and injection rates when only limited data is available. The software determines the extraction/injection rates, in pre-specified locations, needed for immobilizing and/or extracting a groundwater contaminant plume. In the optimization problem, the objective function can be either to minimize the extraction/injection rates needed {linear) or to minimize the hydraulic power used for lifting water (quadratic). In either case, different weights can be assigned to emphasize any time period. …

Optimizing Conjunctive Water Use In A Dynamic Stream Aquifer System, Getachew Belaineh, Richard C. Peralta

Civil and Environmental Engineering Faculty Publications

Long-term water management planning models frequently use large time steps and must employ fairly crude assumptions (such as average climatic conditions, etc.). Managing stream aquifer systems during a dry season requires using finer discretization in time and space. Presented is a computer model, US/REMAX, developed by Utah State University personnel for aiding best management of stream-aquifer systems for both long and short eras. The model computes strategies for optimally allocating surface and ground water resources in time and space. For a water supply problem the model can maximize the sum of delivered surface and ground water. For an environmental protection …

Method For Stripping Metals In Solvent Extraction, Thomas J. O'Keefe

Materials Science and Engineering Faculty Research & Creative Works

Aqueous solutions containing metal cations, that may include cations of both desired metal and impurity or secondary metal, are treated with an organic liquid extractant suitable for the extraction of cations of the desired metal, cations of at least one secondary metal being co-extracted. After phase disengagement, the loaded organic phase containing cations of either a desired metal or desired metal together with at least one secondary metal is contacted with a solid metal or solid metal alloy capable of reducing in the organic phase cations of either a desired metal or a secondary metal from a higher to a …