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Articles 67021 - 67050 of 75081

Full-Text Articles in Engineering

Design Provisions For Cold-Formed Steel Column And Beam Columns, Committee On Specifications For The Design Of Cold-Formed Steel Structural Members Sep 1992

Design Provisions For Cold-Formed Steel Column And Beam Columns, Committee On Specifications For The Design Of Cold-Formed Steel Structural Members

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

No abstract provided.


Practical Constraints Pertinent To The Design Of Neural Networks, Said Sadek Abdallah, Rufus H. Cofer Aug 1992

Practical Constraints Pertinent To The Design Of Neural Networks, Said Sadek Abdallah, Rufus H. Cofer

Electrical Engineering and Computer Science Faculty Publications

in designing a feedforward neural network for numerical computation using the backpropagation algorithm it is essential to know that the resulting network has a practical global minimum, meaning that convergence to a stationary solution can be achieved in reasonable time and using a network of reasonable size. This is in contrast to theoretical results indicating that any square-integrable (L2) function can be computed assuming that an unlimited number of neurons are available. A class of problems is discussed that does not fit into this category. Although these problems are conceptually simple, it is shown that in practice convergence to a …


Dynamic Analysis Of Space-Related Linear And Nonlinear Structures, Paul A. Bosela, F. J. Shaker, D. G. Ertis Aug 1992

Dynamic Analysis Of Space-Related Linear And Nonlinear Structures, Paul A. Bosela, F. J. Shaker, D. G. Ertis

Civil and Environmental Engineering Faculty Publications

In order to be cost-effective, space structures must be extremely light-weight, and subsequently, very flexible structures, The power system for Space Station 'Freedom' is such a structure. Each array consists of a deployable truss mast and a split 'blanket' of photo-voltaic solar collectors. The solar arrays are deployed in orbit, and the blanket is stretched into position as the mast is extended. Geometric stiffness due to the preload make this an interesting non-linear problem. The space station will be subjected to various dynamic loads, during shuttle docking, solar tracking, attitude adjustment, etc. Accurate prediction of the natural frequencies and mode …


Remote Driving With Reduced Bandwidth Communication, Fred W. Depiero, Timothy E. Noell, Timothy F. Gee Aug 1992

Remote Driving With Reduced Bandwidth Communication, Fred W. Depiero, Timothy E. Noell, Timothy F. Gee

Electrical Engineering

Oak Ridge National Laboratory has developed a real-time video transmission system for low-bandwidth remote operations. The system supports both continuous transmission of video for remote driving and progressive transmission of still images. Inherent in the system design is a spatiotemporal limitation to the effects of channel errors. The average data rate of the system is 64,000 bits/s, a compression of approximately 1000:1 for the black and white National Television Standard Code video. The image quality of the transmissions is maintained at a level that supports teleoperation of a high-mobility multipurpose wheeled vehicle at speeds up to 15 mph on a …


Ground-Water Policy-Making Support: Usem Optimization Modelling Plus Gis And Graphics, Richard C. Peralta, Christopher M. U. Neale, Ali Gharbi, Mazibur Khan, Oscar Daza, Douglas Ramsey, Kurt Vest Aug 1992

Ground-Water Policy-Making Support: Usem Optimization Modelling Plus Gis And Graphics, Richard C. Peralta, Christopher M. U. Neale, Ali Gharbi, Mazibur Khan, Oscar Daza, Douglas Ramsey, Kurt Vest

Civil and Environmental Engineering Faculty Publications

A support tool for ground-water management decision making involves integration of a multiobjective optimization model, GIS and graphics software. Two results are improved consideration of spatial data within the optimization model and improved conversion of optimal strategies to real-world application. Another result is improved visualization of the trade-offs involved between conflicting management goals.


Ccfss Technical Bulletin August 1992, Wei-Wen Yu Center For Cold-Formed Steel Structures Aug 1992

Ccfss Technical Bulletin August 1992, Wei-Wen Yu Center For Cold-Formed Steel Structures

CCFSS Technical Bulletins (1993 - 2020)

No abstract provided.


Design Curves For The Reuse Of Stormwater, Martin Wanielista Aug 1992

Design Curves For The Reuse Of Stormwater, Martin Wanielista

BMP Trains Research and Publications

No abstract provided.


Acuta Enews August 1992, Vol. 21, No. 8 Aug 1992

Acuta Enews August 1992, Vol. 21, No. 8

ACUTA Newsletters

In This Issue

FCC gives nod to touch-tone video

President's column

West Chester starting student resale

Security at Yale

ACUTA Calender

Phone taps snare hackers


Ccfss News August 1992, Wei-Wen Yu Center For Cold-Formed Steel Structures Aug 1992

Ccfss News August 1992, Wei-Wen Yu Center For Cold-Formed Steel Structures

CCFSS Newsletters (1999 - 2008)

No abstract provided.


Measured Electricity Savings Of Refrigerator Replacement: Case Study And Analysis, Florida Solar Energy Center, Ted Stedman Aug 1992

Measured Electricity Savings Of Refrigerator Replacement: Case Study And Analysis, Florida Solar Energy Center, Ted Stedman

FSEC Energy Research Center®

There are approximately seven million refrigerator-freezers in the State of Florida. The average demand of these units is at least 1,000 MW. The average life of a residential refrigerator is approximately 20 years (U.S. DOE, 1989). At least 25% of Florida's existing stock are old inefficient units built before the advent of recent appliance efficiency standards. The least efficient are existing models of which approximately 5% of the stock is replaced each year. This represents a significant opportunity for efficiency improvement since recently established standards will greatly improve refrigerator efficiency by 1993 (NAECA, 1987). A number of studies have identified …


Performance Of A Modified Turned-Down Guardrail End Treatment In Traffic Accidents, Kenneth R. Agent, Jerry G. Pigman Aug 1992

Performance Of A Modified Turned-Down Guardrail End Treatment In Traffic Accidents, Kenneth R. Agent, Jerry G. Pigman

Kentucky Transportation Center Research Report

The objective of this study was to report the results of the continued monitoring of the performance of the modified turned-down guardrail end treatment (Type 7) in traffic accidents. Data for a total of 67 accidents involving the modified turned-down guardrail end treatment were identified. Performance was classified as proper in 51 of the 61 accidents (84 percent) in which it was determined. In the majority of the accidents in which proper performance occurred, the vehicle either traveled onto the top at the guardrail beyond the breakaway section or broke through the breakaway posts and proceeded behind the guardrail.

The …


Solutions Of The Heat Conduction Equation In Multilayers For Photothermal Deflection Experiments, William A. Mcgahan, Kevin D. Cole Aug 1992

Solutions Of The Heat Conduction Equation In Multilayers For Photothermal Deflection Experiments, William A. Mcgahan, Kevin D. Cole

Department of Mechanical and Materials Engineering: Faculty Publications

Exact expressions are presented for the deflection of a laser beam passing parallel to and above the surface of a sample heated by a periodically modulated axisymmetric laser beam. The sample may consist of any number of planar films on a thick substrate. These exact expressions are derived from a local Green’s function treatment of the heat conduction equation, and contain an exact analytical treatment of the absorption of energy in the multilayered system from the heating laser. The method is based on calculation of the normal component of the heat fluxes across the layer boundaries, from which either the …


Design And Performance Of A Bituminous Surface Mixture Containing Bottom Ash Aggregate, David Q. Hunsucker Aug 1992

Design And Performance Of A Bituminous Surface Mixture Containing Bottom Ash Aggregate, David Q. Hunsucker

Kentucky Transportation Center Research Report

A one-mile experimental bituminous surface overlay was placed in October 1987 on State Route 3 in Lawrence County, Kentucky. The experimental section utilized bottom ash aggregate from the Kentucky Power Company's Big Sandy Power Plant, near Louisa, Kentucky. Bottom ashes are generally angular and have very porous surfaces. Approximately 539 tons of the experimental bituminous surface material, containing 40 percent bottom ash (dry weight), were placed. Reported herein are results of laboratory tests and performance evaluations of the experimental surface mixture.

Performance of the experimental bottom ash surface has been excellent. Skid resistance tests indicate the surface is highly skid …


Youth Needs And Assessment Survey, Kenneth R. Agent, Jerry G. Pigman Aug 1992

Youth Needs And Assessment Survey, Kenneth R. Agent, Jerry G. Pigman

Kentucky Transportation Center Research Report

The characteristics of traffic accidents involving teenage (16 to 19 years of age) drivers are summarized in this report and compared to all accidents. This was accomplished through an analysis of statewide accident data for a three-year period (1989 through 1991). Counties having the highest overrepresentation of accidents involving teenage drivers were identified. The status of highway safety programs currently in place in school districts in Kentucky is presented. A survey was sent to 182 school districts in Kentucky with a 64 percent response rate obtained. Relevant literature was reviewed, and summary statements are given in the Appendix. This summary …


Modeling Of A-Si : H Deposition In A Dc Glow Discharge Reactor, Dariusz Orlicki, Vladimir Hlavacek, Hendrik J. Viljoen Aug 1992

Modeling Of A-Si : H Deposition In A Dc Glow Discharge Reactor, Dariusz Orlicki, Vladimir Hlavacek, Hendrik J. Viljoen

Papers in Reaction Kinetics

PECVD reactors are increasingly used for the manufacturing of electronic components. This paper presents a reactor model for the deposition of amorphous hydrogenated silicon in a dc glow discharge of Ar-SiH4 The parallel-plate configuration is used in this study. Electron and positive ion densities have been calculated in a self-consistent way. A macroscopic description that is based on the Boltzmann equation with forwardscattering is used to calculate the ionization rate. The dissociation rate constant of SiH4 requires knowledge about the electron energy distribution function. Maxwell and Druyvesteyn distributions are compared and the numerical results show that the deposition …


Review: 'Theory Of Dielectric Optical Waveguides,' 2nd Edition, By Dietrich Marcuse, Bradley D. Duncan Aug 1992

Review: 'Theory Of Dielectric Optical Waveguides,' 2nd Edition, By Dietrich Marcuse, Bradley D. Duncan

Electro-Optics and Photonics Faculty Publications

I suppose I ought to say up front that while preparing this review I often found myself feeling very much like a student evaluating his teacher. After all, it was, in part, the first edition of Dietrich Marcuse's Theory of Dielectric Optical Waveguides (among a handful of other similar texts) from which I first studied the principles of optical waveguide theory under the demanding, yet patient and graceful guidance of Dr. Ahmad Safaai-Jazi. Thus with the utmost respect for a teacher whom I have never met, I shall try to faithfully share my thoughts and feelings regarding the second edition …


Beginning Of Motion For Selected Unanchored Residue Materials, John E. Gilley, Eugene R. Kottwitz Aug 1992

Beginning Of Motion For Selected Unanchored Residue Materials, John E. Gilley, Eugene R. Kottwitz

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Conservation tillage systems help to maintain residue materials from the previous crop on the soil surface. The potential for serious erosion may exist if crop residues are removed by overland flow. This study is conducted to identify the hydraulic conditions required to initiate residue movement by overland flow. Corn, cotton, peanut, pine needles, sorghum, sunflower, and wheat residue are placed in a flume on smooth and sand surfaces, and flow is then introduced in progressive increments. The discharge rate and flow velocity required to initiate residue movement are identified. Hydraulic measurements are used to calculate the ratio of critical flow …


An Optical Technique For Measurement Of Semiconductor Surface Electric Fields, Harshad P. Sardesai, William C. Nunnally Aug 1992

An Optical Technique For Measurement Of Semiconductor Surface Electric Fields, Harshad P. Sardesai, William C. Nunnally

P. F. (Paul Frazer) Williams Publications

We present an optical technique for the measurement of semiconductor surface electric fields. The measurement technique uses the Kerr electro-optic effect in nitrobenzene, a phase sensitive interferometer, and associated data acquisition units to measure the surface electric fields between the contacts of a planar semiconductor device. This technique was used to measure the surface fields on silicon devices used in pulsed power applications, but has the potential for use as an electric field probe for any device having high surface electric fields, both pulsed and dc. The measurement technique showed a temporal resolution of 100 ns, which can be easily …


Us/Wells Vs. 1.05 User's Manual, Alaa H. Aly, Richard C. Peralta Aug 1992

Us/Wells Vs. 1.05 User's Manual, Alaa H. Aly, Richard C. Peralta

Civil and Environmental Engineering Faculty Publications

Presented is a computer program, US/WELLS, that is designed to solve several types of groundwater management problems. The acronym US/WELLS stands for Utah State WELL System. This decision-support tool is usable by persons slightly familiar with groundwater hydraulics. It can be valuable for practical management of groundwater systems that satisfy certain criteria.


Dna Mapping Algorithms: Strategies For Single Restriction Enzyme And Multiple Restriction Enzyme Mapping, Will Gillett Aug 1992

Dna Mapping Algorithms: Strategies For Single Restriction Enzyme And Multiple Restriction Enzyme Mapping, Will Gillett

All Computer Science and Engineering Research

An approach to high-resolution restriction-fragment DNA mapping, known as Multiple-Restriction-Enzyme mapping (MRE mapping), is present. This approach significantly reduces the uncertainty of clone placement by using clone ends to synchronize the position in of clones within different maps, each map being constructed from fragment-length data produced by digestion of each clone with a specific restriction enzyme. Maps containing both fragments-length data and clone-end data are maintained for each restriction enzyme, and synchronization between two such maps is achieved by requiring them to have "compatible" clone-end map projections. Basic definitions of different kinds of maps, such as restriction sites maps, restriction …


Integrated Optical Transmitters And Receivers Using Multi-Segment Laser Processes, J. G. Wasserbauer, Dennis J. Derickson, K. Giboney, R. J. Helkey, J. R. Karin, A. Mar, J. E. Bowers Jul 1992

Integrated Optical Transmitters And Receivers Using Multi-Segment Laser Processes, J. G. Wasserbauer, Dennis J. Derickson, K. Giboney, R. J. Helkey, J. R. Karin, A. Mar, J. E. Bowers

Electrical Engineering

No abstract provided.


Electroluminescence And Electrical Transport In Poly(3-Octylthiophene) Diodes, David Braun, G. Gustafsson, D. Mcbranch, A. J. Heeger Jul 1992

Electroluminescence And Electrical Transport In Poly(3-Octylthiophene) Diodes, David Braun, G. Gustafsson, D. Mcbranch, A. J. Heeger

Electrical Engineering

We report visible light emission from diodes made from poly(3-octylthiophene). Use of a soluble derivative of polythiophene allows fabrication of the light emitting diodes by casting the polymer film from solution with no subsequent processing or heat treatment required. The devices emit dim red-orange light with relatively low external quantum efficiencies, below 2.5×10−5 photons per electron at room temperature. Electrical characterization reveals diode behavior with rectification ratios greater than 102. The temperature dependence indicates that tunneling phenomena dominate the charge injection.


Can Pac Learning Algorithms Tolerate Random Attribute Noise?, Sally A. Goldman, Robert H. Sloane Jul 1992

Can Pac Learning Algorithms Tolerate Random Attribute Noise?, Sally A. Goldman, Robert H. Sloane

All Computer Science and Engineering Research

This paper studies the robustness of pac learning algorithms when the instances space is {0,1}n, and the examples are corrupted by purely random noise affecting only the instances (and not the labels). In the past, conflicting results on this subject have been obtained -- the "best agreement" rule can only tolerate small amounts of noise, yet in some cases large amounts of noise can be tolerated. We show that the truth lies somewhere in between these two alternatives. For uniform attribute noise, in which each attribute is flipped independently at random with the same probability, we present an algorithm that …


Acuta Enews July 1992, Vol. 21, No. 7 Jul 1992

Acuta Enews July 1992, Vol. 21, No. 7

ACUTA Newsletters

In This Issue

President's column

Two Region Directors elected

Party Line

Northeast Region meeting


Discourse-Level Analysis Of Abstracts For Information Retrieval: A Probabilistic Approach, Robert N. Oddy Jul 1992

Discourse-Level Analysis Of Abstracts For Information Retrieval: A Probabilistic Approach, Robert N. Oddy

School of Information Studies - Faculty Scholarship

The objective of this research is to contribute to our knowledge of how people seek information, and how computer systems can be designed to help in this process. Most information retrieval research since the field emerged in the 1950's has reduced these questions to that of trying to determine how documents relevant to a user's query might be selected from a large collection of texts---a question that has proved remarkably difficult to answer. The present work takes the stance that this particular reduction increasingly limits progress towards the objective stated above. It is directed instead towards the development of a …


Application Of An Itô-Based Approximation Method To Random Vibration Of A Pinching Hysteretic System, Mohammad N. Noori, Mark D. Padua, Hamid Davoodi Jul 1992

Application Of An Itô-Based Approximation Method To Random Vibration Of A Pinching Hysteretic System, Mohammad N. Noori, Mark D. Padua, Hamid Davoodi

Office of the Dean (CENG) Scholarship

In this paper, an extension of the Cumulant-Neglect closure scheme is utilized for the random vibration analysis of a single degree of freedom system with a general pinching hysteresis restoring force. The hysteresis element used in the system model can simulate commonly observed forms of stiffness, strength and pinching degradations. The second order statistics of the system response to a stationary Gaussian white noise input are derived using an Itô-based approximation technique. The validity of these response statistics are then verified by comparing them to Monte Carlo simulation results. The numerical studies performed for different combinations of degradation parameters and …


The Calendar - July And August 1992, Nova University Jul 1992

The Calendar - July And August 1992, Nova University

The Calendar

No abstract provided.


In Vitro Development Of Zygotes From Prepubertal Gilts After Microinjection Of Dna, B. L. Williams, J. L. Johnson, A. E.T. Sparks, R. S. Canseco, J. W. Knight, William H. Velander, R. L. Page, W. N. Drohan, J. M. Young, R. E. Pearson, T. D. Wilkins, F. C. Gwazdauskas Jul 1992

In Vitro Development Of Zygotes From Prepubertal Gilts After Microinjection Of Dna, B. L. Williams, J. L. Johnson, A. E.T. Sparks, R. S. Canseco, J. W. Knight, William H. Velander, R. L. Page, W. N. Drohan, J. M. Young, R. E. Pearson, T. D. Wilkins, F. C. Gwazdauskas

Papers in Biotechnology

The effect of pronuclear microinjection of DNA and culture in excised mouse oviducts on the development of porcine zygotes was assessed in this study. Precocious ovulation was induced in prepubertal gilts with pregnant mare's serum gonadotrophin and hCG. Zygotes received either pronuclear microinjection of buffer alone, buffer containing a DNA construct, or no microinjection. Zygotes were cultured in vitro in either modified Krebs-Ringer bicarbonate medium (KRBI for 144 h or in mouse oviduct (MO) explant culture with KRB for 48, 72, 96, or 120 h. Pronuclear microinjection of DNA resulted in a lower (P < .05) cleavage index (CII than did buffer or no microinjection (CI 2.16 k .10 vs 2.80 f .13 and 2.93 f .lo). The CI loss was greatest for DNA-injected zygotes at the two-cell stage of development. Coculture of zygotes in MO resulted in a higher CI (P < .01) than did culture in KRB. Culture in MO for 72 h was the most beneficial system compared with MO for 48, 96, or 120 h (P < .05; CI 3.25 k .12 vs 2.66 k .18, 2.79 f .14, and 2.40 .14, respectively). Microinjection of DNA, not merely the mechanical procedure, was detrimental to early zygote development and may be the cause of low pregnancy rates.


Analysis Of Multifrequency Dispersive Optical Bistability And Switching In Nonlinear Ring Cavities With Large Medium-Response Times, Pawel Pliszka, Partha P. Banerjee Jul 1992

Analysis Of Multifrequency Dispersive Optical Bistability And Switching In Nonlinear Ring Cavities With Large Medium-Response Times, Pawel Pliszka, Partha P. Banerjee

Electrical and Computer Engineering Faculty Publications

Using a simple model of a ring cavity comprising a cubically nonlinear medium, we analyze dispersive optical bistability in the presence of more than one spectral component. We show the phenomenon of so-called competition for resonance. In addition to presenting cavity characteristics for the cases of two and three different frequencies, we also discuss the general method for finding steady-state solutions and checking their stability. A simple and efficient algorithm, based on a relaxation method, is devised to find steady-state solutions satisfying appropriate boundary conditions. The relaxation dynamics is physically related to a finite response time of the medium.


Experimental Road Base Construction Utilizing Atmospheric Fluidized Bed Combustion Residue, David Q. Hunsucker, R. Clark Graves Jul 1992

Experimental Road Base Construction Utilizing Atmospheric Fluidized Bed Combustion Residue, David Q. Hunsucker, R. Clark Graves

Kentucky Transportation Center Research Report

This report summarizes findings of laboratory and field trial evaluations of two experimental test sections constructed adjacent to one another. One experimental section contained a mixture of pulverized fuel ash, residue from an atmospheric fluidized bed combustion process, and limestone aggregate. The second section contained a similar mixture but included a small amount of Type Ill cement. Both experimental sections were constructed to a total nominal thickness of nine inches. The typical design section included six inches of the experimental mixtures, used as base materials, beneath three inches asphaltic concrete. A previous report documented construction of the test sections and …