Engineering Commons^™

Pv Powering A Weather Station For Severe Weather, Florida Solar Energy Center, William Young

FSEC Energy Research Center®

A natural disaster, such as Hurricane Andrew, destroys thousands of homes and businesses. The destruction from this storm left thousands of people without communications, potable water, and electric power. This prompted the Florida Solar Energy Center to study the application of solar electric power for use in disasters.

During this same period, volunteers at the Tropical Prediction Center at the National Hurricane Center (NHC) and the Miami Office of the National Weather Service (NWS) were working to increase the quantity and quality of observations received from home weather stations.

Many weather data collecting stations are at remote sites, which are …

Infrared Optical Properties Of Mixed-Phase Thin Films Studied By Spectroscopic Ellipsometry Using Boron Nitride As An Example, Mathias Schubert, B. Rheinlander, E. Franke, H. Neumann, T. E. Tiwald, John A. Woollam

Department of Electrical and Computer Engineering: Faculty Publications

We present a microstructure-dependent anisotropic infrared-optical dielectric function model for mixed-phase polycrystalline material from which we derive the transverse and longitudinal-optical modes observable in thin films. Infrared ellipsometry over the wavelength range from 700 to 3000 cm^-1 is then used to determine the phase and microstructure of polycrystalline and multilayered hexagonal and cubic boron nitride thin films deposited by magnetron sputtering onto (100) silicon. The ellipsometric data depend on the thin-film multilayer structure, the layer-phase composition, and the average orientation of the hexagonal grain c axes. In particular, we demonstrate the existence of spectral shifts of longitudinal optical phonons …

Milled Carbon Fiber Reinforced Polymer Composition, Brian Massengale, Paul Schauer, Charles Dahle, Barry Gregerson, Bonnie Bachman, Thomas Oesterle

Economics Faculty Research & Creative Works

A milled carbon fiber reinforced polymer having increased abrasion resistive characteristics. The reinforced polymer comprises a base resin selected from the group consisting of polyolefins and polyamides. The base resin is combined with an amount of milled carbon fibers and further may be combined with polytetrafluoroethylene. The resulting composite materials have excellent friction and wear characteristics and are useful in the production of injection molded parts. The molded parts have a high impact strength, exhibit dimensional stability, are abrasion resistive, and are static dissipative, with the composite materials having particular utility as support fixtures for semiconductors during certain processing operations.

A New Control Strategy For A Signalized Traffic Intersection, Allen R. Stubberud, Xiao-Hua Yu

Electrical Engineering

A traffic control problem can be formulated as a decision-making problem for a stochastic dynamic system. Optimal traffic signal settings at intersections can minimize the vehicle delay time or the queue length at a stop line. In this paper, a new adaptive control strategy for signalized intersections is developed and tested by simulation. The simulation results show significant improvement over the traditional fully actuated control algorithm, especially for the case of high volume traffic demand.

Crossflow Microfiltration Of Recombinant Escherichia Coli Lysates After High Pressure Homogenization, Stuart M. Bailey, Michael M. Meagher

Papers in Biotechnology

Abstract: Crossflow membrane filtration was used to process recombinant Escherichia coli cell lysates containing protein inclusion bodies after high pressure homogenization. The number of passes through the high pressure homogenizer changed the viscosities and average particle sizes of the cell lysates. The different cell lysates were processed with a hollow fiber unit containing microfiltration membranes and a plate and frame unit with either ultrafiltration or microfiltration membranes. There were differences in permeate flux and protein transmission for the various membranes with the best performing membranes giving permeate fluxes greater than 60 L m−2 h−1 and protein transmissions greater than 90%. …

35. Shigeharu Onogi, Otto Vogl, Masaoki Takahashi, Toshiro Masuda

Emeritus Faculty Author Gallery

No abstract provided.

Japan-Us Seminar: Macromolecular Architecture And Engineering, Otto Vogl, Shin-Ichiro Shoda

Emeritus Faculty Author Gallery

No abstract provided.

Seismic Response Of Asymmetric Systems: Energy-Based Approach, Rakesh K. Goel

Civil and Environmental Engineering

An energy-based approach has been used to investigate the seismic behavior of code-designed asymmetric-plan systems. The systems considered in this investigation had large eccentricities in both directions, were designed for bidirectional earthquake loading, and their responses were computed with both components of ground motion acting simultaneously. The presented results demonstrate that the total input energy is about the same whether the system plan is symmetric or asymmetric. Furthermore, flexible-side elements in asymmetric- plan systems may be more vulnerable to earthquakes than the same elements in symmetric-plan systems if they are not designed to accommodate the higher hysteretic-energy demands. This observation …

Period Formulas For Moment-Resisting Frame Buildings, Rakesh K. Goel, Anil K. Chopra

Civil and Environmental Engineering

Most seismic codes specify empirical formulas to estimate the fundamental vibration period of buildings. Evaluated first in this paper are the formulas specified in present U.S. codes using the available data on the fundamental period of buildings "measured" from their motions recorded during eight California earthquakes, starting with the 1971 San Fernando earthquake and ending with the 1994 Northridge earthquake. It is shown that, although the code formulas provide periods that are generally shorter than measured periods, these formulas can be improved to provide better correlation with the measured data. Subsequently, improved formulas for estimating the fundamental periods of reinforced …

Earthquake Characteristics Of Bridges With Integral Abutments, Rakesh K. Goel

Civil and Environmental Engineering

Earthquake analysis of bridges requires that the period and damping ratio be determined for each significant mode of vibration. Data on these vibration properties, identified from motions of bridges recorded during actual earthquake events, provide the most direct means of verifying and improving the current guidelines. Thus, the aim of this investigation was to measure the vibration properties of a two-span concrete bridge from its motions recorded during actual earthquake events. These data were then used to investigate how abutment participation affected the vibration properties of bridges with integral abutments. It is shown that the vibration period elongated and the …

Accuracy Of Irrigation Efficiency Estimates, A. J. Clemmens, Charles M. Burt

BioResource and Agricultural Engineering

Evaluation of actual irrigation system performance should rely on an accurate hydrologic water balance over the area considered. In a companion paper, water uses are categorized as consumptive or nonconsumptive, and beneficial or nonbeneficial. Real performance is based on water uses over a specified period of time, rather than observation of a single irrigation event (with associate potential, but not yet actual, consumptive and/or beneficial uses). Once the components in the water balance have been determined, it is shown that the accuracy of irrigation performance parameters can be determined from the accuracy of the components in the water balance, using …

Irrigation Performance Measures: Efficiency And Uniformity, Charles M. Burt, Albert J. Clemmens, Theodor S. Strelkoff, Kenneth H. Solomon, Ronald D. Bliesner, Leland A. Hardy, Terry A. Howell, Dean E. Eisenhauer

BioResource and Agricultural Engineering

It is essential to standardize the definitions and approaches to quantifying various irrigation performance measures. The ASCE Task Committee on Defining Irrigation Efficiency and Uniformity provides a comprehensive examination of various performance indices such as irrigation efficiency, application efficiency, irrigation sagacity, distribution uniformity, and others. Consistency is provided among different irrigation methods and different scales. Clarification of common points of confusion is provided, and methods are proposed whereby the accuracy of numerical values of the performance indicators can be assessed. This issue has two companion papers that provide more detailed information on statistical distribution uniformity and the accuracy of irrigation …

Spectroscopic Ellipsometry And Magneto-Optic Kerr Effects In Co/Pt Multilayers, Xiang Gao, Darin W. Glenn, Scott Heckens, Daniel W. Thompson, John A. Woollam

Department of Electrical and Computer Engineering: Faculty Publications

Control of thickness and microstructure is critical in the preparation of ultrathin metallic multilayers for magneto-optic memory, computer read heads, and improved wear surfaces. This paper describes use of in situ spectroscopic ellipsometry to calibrate sputter deposition rates, control layer thicknesses, determine optical constants, and study oxidation rates and processes. In this work, the information gained in situ is used together with ex situ Kerr measurements to determine the complete magneto-optic response including the spectroscopic figure of merit for Co/Pt multilayers.

Stratospheric Loading Of Sulfur From Explosive Volcanic Eruptions, Gregg J. Bluth, William I. Rose, Ian E. Sprod, Arlin J. Krueger

Department of Geological and Mining Engineering and Sciences Publications

This paper is an attempt to measure our understanding of volcano/atmosphere interactions by comparing a box model of potential volcanogenic aerosol production and removal in the stratosphere with the stratospheric aerosol optical depth over the period of 1979 to 1994. Model results and observed data are in good agreement both in magnitude and removal rates for the two largest eruptions, El Chicho´n and Pinatubo. However, the peak of stratospheric optical depth occurs about nine months after the eruptions, four times longer than the model prediction, which is driven by actual SO2 measurements. For smaller eruptions, the observed stratospheric perturbation is …

Phase Diagrams Of A Binary Smectic-A Mixture, Hao-Wen Chiu, Thein Kyu

College of Polymer Science and Polymer Engineering

A variety of smectic phase diagrams involving smectic-isotropic and smectic-nematic-isotropic transitions have been calculated based on a combination of Flory-Huggins (FH) theory for isotropic mixing and Maier-Saupe-McMillan (MSM) theory for smectic-A ordering of liquid crystals (LC). To describe the mesophase transitions, two nematic order parameters and two smectic order parameters have been coupled through the normalized orientation distribution and partition functions. Flory-Huggins interaction parameter (chi) for isotropic mixing and the coupling term involving the nematic interaction parameter (nu) and the McMillan smectic interaction parameter (alpha) for phase transitions of liquid crystals have been incorporated in the calculation. The predictive capability …

Acuta Enews November 1997, Vol. 26, No. 11

ACUTA Newsletters

In This Issue

Second Annual ACUTA Student Paper Competition

SLCC Telecom Bails Out

Board Report

SLCC

President's Column

Negotiating a Wireless Contract

Seminar Looks at Networks, Legislative & Regulatory Issue

Is There a Back Door to Your Long Distance?

DC at a Glance

Welcome New Members

Rat Wire Schools

Spotlight

Spinal Cord Stimulation For Chronic Pain Management: Towards An Expert System, Kenneth M. Alo, Richard Alo, Andre De Korvin, Vladik Kreinovich

Departmental Technical Reports (CS)

Chronic pain is a serious health problem affecting millions of people worldwide. Currently, spinal cord simulation is one of the most effective methods of easing the chronic pain. For most patients, a careful selection of weak electric currents enables to drastically decrease the pain level. The first devices offered only a few possible regimes, and it was possible to choose an appropriate regime simply by exhaustive search. Continuous engineering progress leads to more and more flexible devices that offer a wide variety of millions of possible simulation regimes. With this variety, it is no longer possible to test all of …

From Fuzzification And Intervalization To Anglification: A New 5d Geometric Formalism For Physics And Data Processing, Scott A. Starks, Vladik Kreinovich

Departmental Technical Reports (CS)

No abstract provided.

From Expert Words Directly To Numerical Simulations: Group-Theoretic Approach To Computing With Words In Information/Intelligent Systems, Vladik Kreinovich, Brian Penn, Scott A. Starks

Departmental Technical Reports (CS)

In many real-life situations, e.g., when making an environmental decision, it is important to be able to predict long-term consequences of different decisions. Very often, these predictions must be done in the situation where the only available information consists of expert rules, which are formulated by words from natural language. One possible way to transform these expert words into numerical simulation (leading to prediction) is to use the fuzzy control methodology. However, there is a problem with using this methodology: it invokes replacing each word by a membership function, and this replacement drastically increases the required computer space (and thus, …

Radiation Imaging Operators Applied To The Detection Of Velocity And Density Contrast Boundaries, Md. Ishfaqur Raza, Richard E. Dubroff, James L. Drewniak

Electrical and Computer Engineering Faculty Research & Creative Works

A procedure for imaging interfaces formed by simultaneous density and velocity contrasts in acoustic media is described. The procedure is based on the properties of radiation imaging operators - a class of linear differential operators parametrically dependent on the acoustic properties of the media. An example of this procedure is demonstrated through the use of numerical simulation. Results, in the form of interface images, are shown, assuming the bulk acoustic characteristics (velocity and density) on both sides of the interface are known.

Simulation Study Of Learning Automata Games In Automated Highway Systems, Cem Unsal, Pushkin Kachroo, John S. Bay

Electrical & Computer Engineering Faculty Research

One of the most important issues in Automated Highway System (AHS) deployment is intelligent vehicle control. While the technology to safely maneuver vehicles exists, the problem of making intelligent decisions to improve a single vehicle’s travel time and safety while optimizing the overall traffic flow is still a stumbling block. We propose an artificial intelligence technique called stochastic learning automata to design an intelligent vehicle path controller. Using the information obtained by on-board sensors and local communication modules, two automata are capable of learning the best possible (lateral and longitudinal) actions to avoid collisions. This learning method is capable of …

Sliding Mode For User Equilibrium Dynamic Traffic Routing Control, Pushkin Kachroo, Kaan Ozbay

Electrical & Computer Engineering Faculty Research

Presents a solution to the user equilibrium dynamic traffic routing (DTR) problem for a point diversion case using feedback control methodology. The sliding mode control technique which is a robust control methodology applicable to nonlinear systems in canonical form is employed to solve the user equilibrium DTR problem. The canonical form for this problem is obtained by using a feedback linearization technique, and the uncertainties of the system are countered by using the sliding mode principle. Simulation results show promising results.

A Hybrid Fem/Mom Technique For Electromagnetic Scattering And Radiation From Dielectric Objects With Attached Wires, Mohammad Wares Ali, Todd H. Hubing, James L. Drewniak

Electrical and Computer Engineering Faculty Research & Creative Works

A hybrid formulation is presented, which combines the method of moments (MOM) with the edge-based vector finite element method (FEM) to solve electromagnetic radiation problems from structures consisting of an inhomogeneous dielectric body of arbitrary shape attached to one or more perfectly conducting bodies. While either method alone fails to model these structures efficiently, a combination of both finite element and moment methods provides an excellent way to solve these problems. The FEM is employed to handle the interior domain of inhomogeneous dielectric bodies and the method of moments is used to develop surface integrals that relate the field quantities …

Nonlinear Optimal Control Of A Hydraulically Actuated Positioning System, Timothy Mclain, Randal W. Beard

Faculty Publications

In this paper, the nonlinear optimal control problem is formulated for the position control of an electrohydraulic servo system. The optimal control is given by the solution to the Hamilton-Jacobi-Bellman equation, which in this case cannot be solved explicitly. An alternative method, based upon successive Galerkin approximation, is used to obtain an approximate optimal solution. Preliminary simulation results, demonstrating the application of this approach to the position control of a hydraulically actuated device, are presented.

Modeling Of Surface Hairline-Crack Detection In Metals Under Coatings Using An Open-Ended Rectangular Waveguide, Christian J. Huber, Habibollah Abiri, Stoyan I. Ganchev, R. Zoughi

Electrical and Computer Engineering Faculty Research & Creative Works

A surface-breaking hairline crack or a narrow slot in a metallic specimen when scanned by an open-ended rectangular waveguide probe influences the reflection-coefficient properties of the incident dominant mode. Subsequent recording of a change in the standing-wave pattern while scanning such a surface results in what is known as the crack characteristic signal. Since microwave signals penetrate inside dielectric materials, this methodology is capable of detecting cracks under dielectric coatings of various electrical thicknesses as well. To electromagnetically model the interaction of an open-ended rectangular waveguide with a surface-breaking hairline crack under a dielectric coating, the dielectric-coating layer is modeled …

Annual Assessment Of Customer Needs And Satisfaction, Patsy Anderson, Kris Hockensmith

Kentucky Transportation Center Research Report

The Kentucky Transportation Cabinet, both through its own quality initiative and a statewide "Empower Kentucky" campaign, has a commitment to achieve new levels of quality in the development, construction and maintenance of highways. In order to gage progress, there is a need to establish a baseline of customer satisfaction with the current highway system, and determine needs as perceived by the users of the highway system. As a result, the University of Kentucky Transportation Center, Technology Exchange Unit, was contracted to conduct a customer needs and satisfaction survey. The objectives of this study are to:

A. Ascertain Kentucky highway users' …

Kentucky Transportation Cabinet: Annual Assessment Of Customer Needs And Satisfaction: Mail Survey, Patsy Anderson, Kris Hockensmith

Kentucky Transportation Center Research Report

The Kentucky Transportation Cabinet, both through its own quality initiative and a statewide "Empower Kentucky" campaign, has a commitment to achieve new levels of quality in the development, construction and maintenance of highways. In order to gage progress, there is a need to establish a baseline of customer satisfaction with the current highway system, and determine needs as, perceived by the users of the highway system. As a result, the University of Kentucky Transportation Center, Technology Exchange Unit, was contracted to conduct a customer needs and satisfaction survey. The objectives of this study are to:

A. Ascertain Kentucky highway users' …

An Experimental Procedure For Characterizing Interconnects To The Dc Power Bus On A Multilayer Printed Circuit Board, Hao Shi, James L. Drewniak, Todd H. Hubing, Thomas Van Doren, Fei Sha

Electrical and Computer Engineering Faculty Research & Creative Works

The effectiveness of dc power-bus decoupling is impacted by the inductance associated with interconnect vias in printed circuit boards (PCB's). Adequate characterization of these interconnects is necessary to facilitate modeling and simulation, and to assess the effectiveness of added decoupling. In this study, a measurement procedure is presented for determining the series inductance and resistance of an interconnect with a network analyzer. The validity and limitations of the procedure are discussed. Experimental results of interconnect parameters on an 8 × 10 in ten-layer test-board corroborate those measured with a precision impedance analyzer. The measured interconnect values are used to simulate …

Quantifying Emi Resulting From Finite-Impedance Reference Planes, David M. Hockanson, James L. Drewniak, Todd H. Hubing, Thomas Van Doren, Fei Sha, Cheung-Wei Lam, Lawrence Rubin

Electrical and Computer Engineering Faculty Research & Creative Works

Parasitic inductance in printed circuit board (PCB) geometries can detrimentally impact the electromagnetic interference(EMI) performance and signal integrity of high-speed digital designs. This paper identifies and quantifies the parameters that affect the inductance of some typical PCB geometries. Closed-form expressions are provided for estimating the inductances of simple trace and ground plane configurations.

Waterfall Lasers, Lee W. Casperson

Electrical and Computer Engineering Faculty Publications and Presentations

Laser concepts can be applied to a broad range of physical phenomena. One of the closest parallels occurs with the fluttering oscillations that are sometimes observed in the falling sheets of water associated with fountains, dams, and natural waterfalls. In many respects these fluid feedback oscillations are similar to the electromagnetic modes of typical lasers, and recognition of this similarity led to the interpretation of the waterfall behavior. Gain profiles for the waterfall oscillations are developed, and the relationship of experimental waterfall data to the laser-like models is considered in detail.