Engineering Commons^™

Evaluation Of Caltrans District 10 Automated Warning System, Year Two Progress Report, Art Maccarley

Electrical Engineering

District 10 of the California Department of Transportation (Caltrans) encompasses an area of seasonal fog and dust-related visibility problems that have been the cause of numerous multi-car traffic collisions, many fatal. In 1990, motivated by the expansion of State Route 120 (SR 120) connecting Interstate Highway 5 (I-5) and State Route 99 (SR 99), Caltrans proposed a sophisticated multi-sensor automated warning system as a means for reducing incidents in this high-traffic area. This proposal, and the significant development effort that followed, culminated in the implementation of Phase 1 of the Caltrans Automated Warning System, or “CAWS”, which entered service in …

Santa Clara Magazine, Volume 41 Number 2, August 1999, Santa Clara University

Santa Clara Magazine

8 - APOCALYPSE PAST: Y1K By Thomas Turley. The year 2000 is upon us. But what about Y1K? History Professor Thomas Turley takes an historical look at the millennial fever of a thousand years ago.

12 - THE FUTURE IS MATH By Susan Vogel. Math Lecturer David Sul is on a mission: to get more Hispanics and African-Americans into Calculus and onto college through SCU's Calculus 100 program.

16 - The Class of 1999 Moves On By Sug Ramire '98. Optimism is the byword for the last graduating class of the millennium. Six 1999ers share their impressions, hopes, and fears …

Theoretical Explanation For The Empirical Probability Of Detection (Pod) Curve: A Neural Network-Motivated Approach, Yohans Mendoza, Roberto Osegueda

Departmental Technical Reports (CS)

For non-destructive testing of aerospace structures, it is extremely important to know how the probability of detecting a fault depends on its size. Recently, an empirical formula has been found which described this dependence. In this paper, we provide the theoretical justification for this formula by using methods motivated by the neural network approach.

Fuzzy Logic In Non-Destructive Testing Of Aerospace Structures, Murali Krishna, Vladik Kreinovich, Roberto Osegueda

Departmental Technical Reports (CS)

In nondestructive testing, to locate the faults, we send an ultrasonic signal and measure the resulting vibration at different points. To describe and combine the uncertainty corresponding to different measurements and fuzzy estimates, we used fuzzy logic. As a result, we get reasonably simple computational models which lead to as good fault detection as the known more complicated models.

Emi Associated With Inter-Board Connection For Module-On-Backplane And Stacked-Card Configurations, Xiaoning Ye, Jim Nadolny, James L. Drewniak, Todd H. Hubing, Thomas Van Doren, Richard E. Dubroff

Electrical and Computer Engineering Faculty Research & Creative Works

EMI associated with inter-board connection was studied through common-mode current measurements and FDTD modeling for stacked-card and module-on-backplane configurations. Three types of connections were investigated experimentally including an open pin field connection, an "ideal" semi-rigid coaxial cable connection, and a production connector. Both microstrip and stripline signal routing on the PCB were investigated. The results indicated signal routing on the PCBs or the inter-board connection can dominate the EMI process. Several cases of connector geometries were studied using FDTD modeling and good agreement was achieved between the measured and FDTD results.

Strength And Weaknesses Of Npv Analysis And Its Application To Aircraft Value Modeling, Sebastian Lourier

Master's Theses - Daytona Beach

The purpose of this study is to analyze the Net Present Value (NPV) technique as a mean to forecast aircraft values and the analysis of aircraft value forecasting accuracy. The main part of the examination is the evaluation of the actual quality of aircraft appraisals. The appraisal evaluation is based on historical forecast accuracy determinations and on a comparison of 1998 aircraft value forecasts. The discussion of a survey conducted by the author in 1998, will reveal the disunity among the appraisers. The survey data was provided generously by the appraisers most recognized in the industry. A sensitivity analysis exhibits …

Epoxy-Terminated Self-Assembled Monolayers As Molecular Glues For Polymer Layers, Duangrut Julthongpiput

Masters Theses

Dense, homogeneous, and complete self-assembled monolayers (SAMs) with epoxy surface groups were fabricated from epoxysilanes to serve as a template for chemical anchoring of polymer layers. A combination of scanning probe microscopy, ellipsometry, XPS, X-ray reflectivity, and contact angle measurements was used to study their morphology and surface properties. Self-assembly of epoxysilane molecules resulted in the formation of homogeneous SAMs 0.85 nm thick with the rms surface roughness 0.2 nm. Epoxysilane SAMs were truly monomolecular films with a virtually normal molecular orientation of densely packed molecules, which were firmly attached to the substrate.

Carboxylic acid and anhydride terminated polystyrenes of …

Anticipating Emi From Coupling Between High-Speed Digital And I/O Lines, Wei Cui, Min Li, Xiao Luo, James L. Drewniak, Todd H. Hubing, Thomas Van Doren, Richard E. Dubroff

Electrical and Computer Engineering Faculty Research & Creative Works

The increasing speed of digital circuit design as well as the density of printed circuit board (PCB) layouts often result in more challenging electromagnetic interference (EMI) problems. The coupling between a high-speed digital line and an I/O line can be a primary EMI coupling path, and the attached cable a dominant radiator. This mechanism is studied and modeled herein in a multi-stage modeling fashion. EMI modeling is developed for coupling between the transmission lines, and the attached cable as the EMI antenna. Finally, the EMI is calculated for the coupled noise driving the attached cable. The agreement between the modeled …

Microstrip Coupling Algorithm Validation And Modification Based On Measurements And Numerical Modeling, Theodore M. Zeeff, Chris E. Olsen, Todd H. Hubing, James L. Drewniak, Richard E. Dubroff

Electrical and Computer Engineering Faculty Research & Creative Works

In this study, mutual capacitance and inductance between two coupled traces is measured and computed to validate and simplify coupling algorithms used in an expert system software package. The algorithm's applicability to common microstrip configurations is tested through comparisons between FEM based solutions, |S₂₁| measurements and the algorithm solutions under several permutations of a test board. Adjustments to the original algorithm are proposed that reduce computation times with out significantly affecting the accuracy of the result.

Rf Isolation Using Power Islands In Dc Power Bus Design, Jun Fan, Yong Ren, Juan Chen, David M. Hockanson, Hao Shi, James L. Drewniak, Todd H. Hubing, Thomas Van Doren, Richard E. Dubroff

Electrical and Computer Engineering Faculty Research & Creative Works

Power island structures are often employed for minimizing the propagation of high-frequency noise on DC power buses. The rationale is based on introducing a series impedance in the power plane to provide isolation of a noise source from the rest of the PCB design. The power island concept is investigated herein experimentally, to determine its noise mitigation attributes and limitations. A modeling approach that is suitable for arbitrary PCB island geometries including lumped SMT decoupling capacitors is also presented. The modeling and measurements indicate that island structures can achieve some degree of isolation under certain conditions.

Slot And Aperture Coupling For Airflow Aperture Arrays In Shielding Enclosure Designs, Min Li, James L. Drewniak, Todd H. Hubing, Richard E. Dubroff, Thomas Van Doren

Electrical and Computer Engineering Faculty Research & Creative Works

The coupling between apertures or slots in airflow arrays is investigated numerically by means of the method of moments (MoM). Application to shielding enclosure design is of particular interest. Justification for a previously extracted simple empirical design approach for the relation between the number N and size a of apertures, and the shielding effectiveness ∼Na³ for an airflow aperture array is given. The coupling between slots is also investigated. The application limit of the empirical design approach is demonstrated.

Active Local Volume Displacement Cancellation Of A Vibrating Baffled Beam, Marcellin Zahui

Dissertations

An active noise control apparatus is developed. The device reduces the sound radiated from a vibrating clamped beam. The attenuation of the sound field is obtained through minimization of local volume displacements of the vibrating beam. Two single-input/single-output cancellation devices are used. Each device employs a motion sensor and an acoustic actuator. The actuator is a loudspeaker equipped with a pressure sensor to detect its volume displacement. The motion sensor signal is related to the local volume displacement of the structure which is then reduced by a loudspeaker driven with an equal but opposing volume displacement. The volume displacement sensors …

Nonlinear Robust Missile Autopilot Design Using Successive Galerkin Approximation, Timothy Mclain, Randal W. Beard

Faculty Publications

The application of a new nonlinear robust control strategy to the design of missile autopilots is presented. The control approach described and demonstrated here is based upon the numerical solution of the Hamilton-Jacobi-Isaacs equation by Successive Galerkin Approximation. Using this approach, feedback controllers are computed by an iterative application of a numerical Galerkin-type PDE solver. Application of this approach to the design of a pitch-axis autopilot for a missile having uncertain pitch moment and lift force is described.

Development Of Mechanical Properties Micromapping For Composite Polymer Systems, Zheng Huang

Masters Theses

By adoption of classic indentation models (Hertzian, modified Hertzian, Sneddon, JKR), the elastic properties of polymeric material can be measured by AFM. Heterogeneous thin films were fabricated from polymer blends with a wide range of Young's moduli and thermal transition temperature to test the developed procedure. Results show that the micromapping of elastic properties can be obtained concurrently for glassy and rubber phases as well as across the interface with a lateral resolution better than 100 nm. Application of the elasticity micromapping on heterogeneous polymeric materials reveals thermal transition temperature that coincides very well with bulk values. Depth profile also …

Cell/Dendrite Distribution In Directionally Solidified Hypoeutectic Pb-Sb Alloys, S. P. O'Dell, G. L. Ding, Surendra N. Tewari

Chemical & Biomedical Engineering Faculty Publications

The alloys Pb-2.2 wt pet Sb and Pb-5.8 wt pet Sb were directionally solidified with three different thermal gradients of 40, 86, and 140 K cm(-1) at growth rates ranging from 0.6 to 30 mu m s(-1). A Gaussian peak amplitude analysis of the cell/dendrite spacing distribution shows a distinct peak corresponding to the nearest neighbors. The peaks corresponding to the second and the third nearest neighbor spacings are also brought out by this technique. The ratios of the second to the first nearest neighbor spacings and that of the third to the first neighbor spacings are 1.85 +/-: 0.11 …

Macrosegregation Caused By Thermosolutal Convection During Directional Solidification Of Pb-Sb Alloys, S. N. Ojha, G. L. Ding, Y. Lu, J. Reye, Surendra N. Tewari

Chemical & Biomedical Engineering Faculty Publications

Pb-2.2 and 5.8 wt pet Sb alloys were directionally solidified with a positive thermal gradient of 140 K cm(-1) at growth speeds ranging from 0.8 to 30 mu m s(-1), and then quenched to retain the mushy-zone morphology. Chemical analysis along the length of the directionally solidified portion and in the quenched melt ahead of the dendritic array showed extensive longitudinal macrosegregation, Cellular morphologies growing at smaller growth speeds are associated with larger amounts of macrosegregation as compared with the dendrites growing at higher growth speeds. Convection is caused, mainly, by the density inversion in the overlying melt ahead of …

Conversion Of New Circle Road To A Limited Access Highway, Steven M. Henderson, Nikiforos Stamatiadis

Kentucky Transportation Center Research Report

The objectives of this study were to first evaluate the existing traffic conditions along the NE part of New Circle Road and investigate the use of unconventional left turn treatments, as well as other access restrictions to improve the operating conditions of New Circle Road. The alternatives examined include a do-nothing alternative, the addition of one through lane per direction, the use of median U-turns at various locations, and combinations of them. Restrictive left turn strategies proved to be a more successful tool for traffic management on New Circle Road than simply adding a lane in each direction. Using median …

Cost Effective Concrete Pavement Cross Sections - Interim Report, James Crovetti

Transportation Reports with the Wisconsin Department of Transportation

The present pavement selection policy of the Wisconsin Department of Transportation (WisDOT) limits the design alternatives for Portland Cement Concrete (PCC) pavements and inhibits the designer's ability to select cross-sections deviating from uniform slab thicknesses with doweled transverse joints. Currently, uniform slab thicknesses and conventional joint load transfer devices are incorporated into the design based on the heavy truck traffic in the outer lane. While this strategy provides for adequate pavement structure in this truck lane to limit faulting and slab cracking to tolerable levels, there is a potential for over-design in other traffic lanes which receive significantly lower Equivalent …

Elastic Wave Propagation And Scattering In Heterogeneous, Anisotropic Media: Textured Polycrystalline Materials, Joseph A. Turner

Nebraska Center for Materials and Nanoscience: Faculty Publications

The propagation of elastic waves through heterogeneous, anisotropic media is considered. Appropriate ensemble averaging of the elastic wave equation leads to the Dyson equation which governs the mean response of the field. The Dyson equation is given here in terms of anisotropic elastic Green’s dyadics for the medium with and without heterogeneities. The solution of the Dyson equation for the mean response is given for heterogeneities that are weak. The formalism is further specified for the case of equiaxed cubic polycrystalline metals with a single aligned axis. The Green’s dyadics in this case are those for a transversely isotropic medium. …

Conform- A Computerized Job-Built Concrete Construction Formwork Design, Kajpong Pongponrat

Masters Theses

Economy in formwork design depends partly on the ingenuity and experiences of the form designer, whether a contractor or an engineer. The cost of formwork is significant, generally amounting to anywhere from 40% to 60% of the cost of a concrete structure. Judgment with respect to the development of a forming system could both expedite a project and reduce costs. The present paper addresses the development of CONFORM - an interactive menu driven PC based job-built concrete formwork design. The system is developed using Microsoft Visual Basic 6, Access 97 database, and Word 97, where a perfect integration of these …

Signal Induced Emi In Fibre Channel Cable-Connector Assemblies, Minjia Xu, S. Radu, James L. Knighten, James L. Drewniak, Todd H. Hubing, L. O. Hoeft, J. T. Dibene Ii

Electrical and Computer Engineering Faculty Research & Creative Works

The EMI performance of cable-connector assemblies designed for FC-0 transmission has been studied. Two types of cable and two connector styles were evaluated. Experimental results show that the dominant radiation mechanism for short cable lengths is the common-mode current caused by source and PCB skew that leaks to the exterior of the shield via the transfer impedance of the connector. However, the cable imbalance becomes a more significant source of common-mode current than the source skew when the cable assembly is tens of meters long.

Quantitative, Non-Destructive Calibration Of Scanned Probe Microscope Cantilevers, John Hazel

Masters Theses

Principles of surface science and engineering are applied to determine scanned probe microscope cantilever spring constants. The bi-component gold-ceramic cantilever composition is modeled analytically. Finite element analysis is applied to simulate deflection behavior of the probe tip. Data from experimental determination of resonant frequency are employed to infer material characteristics. Combination of the results from these three procedures is employed to infer material characteristics. Combination of the results from these three procedures is used to produce a spring constant assessment within 10% of actual values. An additional convenient program for assessment of scanning probe microscopy cantilever spring constants is developed …

Application Of A Hybrid Fem/Mom Method To A Canonical Pcb Problem, Yun Ji, J. Chen, Todd H. Hubing, James L. Drewniak

Electrical and Computer Engineering Faculty Research & Creative Works

A hybrid FEM/MOM method was used to solve a canonical printed circuit board (PCB) problem. The PCB is populated with three traces. One is a signal line and the other two are I/O lines that extend beyond the boundary of the board. The finite element method (FEM) was used to model the fields in the volume around the on-board trace. The method of moments (MOM) was employed to model the equivalent surface currents on the board and the current on the off-board traces. The FEM and MOM equations were coupled by forcing the continuity of tangential fields on the dielectric …

Bs News

Building Services Engineering

No abstract provided.

41st Rocky Mountain Conference On Analytical Chemistry

Rocky Mountain Conference on Magnetic Resonance

Final program, abstracts, and information about the 41st 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, August 1-5, 1999.

Comparison Of A Genetic Algorithm And Mathematical Programming To The Design Of Groundwater Cleanup Systems, Alaa H. Aly, Richard C. Peralta

Civil and Environmental Engineering Faculty Publications

We present and apply a new simulation/optimization approach for single- and multiple-planning period problems in groundwater remediation. Instead of the traditional control locations for contaminant concentrations, we use an L_QC norm as a global measure of aquifer contamination (CMAX). We use response-surface constraints to represent CMAX within the optimization model. We compare the performance of formal mixed integer nonlinear programming and a genetic algorithm for several optimization scenarios.

Optimal Design Of Aquifer Clean Up Systems Under Uncertainty Using A Neural Network And A Genetic Algorithm, Alaa H. Aly, Richard C. Peralta

Civil and Environmental Engineering Faculty Publications

We present a methodology to account for the stochastic nature of hydraulic conductivity during the design of pump-and-treat systems for aquifer cleanup. The methodology (1) uses a genetic algorithm to find the global optimal solution and (2) incorporates a neural network to model the response surface within the genetic algorithm. We apply the methodology for a real example and different optimization scenarios. The employed optimization formulation requires few hydraulic conductivity realizations. The presented approach produces a trade-off curve between reliability and treatment facility size .

The Emerald Nanosatellite Mission, Robert J. Twiggs

Robert "Bob" Twiggs STEM Education Collection

A PowerPoint Presentation created by Professor Bob Twiggs titled "The Emerald Nanosatellite Mission" from July 22, 1999.

Improved Wavelet-Based Multiresolution Edge Detection In Noisy Images, Yunwoo Lee, Samuel Peter Kozaitis

Electrical Engineering and Computer Science Faculty Publications

We used the multiresolution property of the discrete wavelet transform to detect edges in noisy images. In our approach, we used wavelets corresponding to 1 and 2 derivatives to generate noisy wavelet coefficients. Then, we compared the wavelet COeffiCientS as a function of scale to reduce the effects of noise. In addition, our approach considered the change in edge position as a function of scale. We analyzed l..D experimental results and compar1 2..D results ofnoisy images to a more common edge detection method. Our results lead to improved edge detection resutts in noisy images.

Foundation Sleeve For A Guardrail System, Dean L. Sicking, John D. Reid, John R. Rohde

Department of Mechanical and Materials Engineering: Faculty Publications

A highway guardrail terminal system having horizontally extending guardrail elements mounted on a plurality of posts. Foundation sleeves having an elongated slit along one side retain and support appropriate guardrail posts. A plurality of stiffing ribs extend across the slit at a distal portion of the tube. The sleeves enable a safer and faster removal of broken guardrail posts after vehicular impact.