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2001

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Articles 31 - 60 of 1795

Full-Text Articles in Engineering

Nonlinear Suppression Of Range Ambiguity In Pulse Doppler Radar, Jon M. Anderson Dec 2001

Nonlinear Suppression Of Range Ambiguity In Pulse Doppler Radar, Jon M. Anderson

Theses and Dissertations

Coherent pulse train processing is most commonly used in airborne pulse Doppler radar, achieving adequate transmitter/receiver isolation and excellent resolution properties while inherently inducing ambiguities in Doppler and range. First introduced by Palermo in 1962 using two conjugate LFM pulses, the primary nonlinear suppression objective involves reducing range ambiguity, given the waveform is nominally unambiguous in Doppler, by using interpulse and intrapulse coding (pulse compression) to discriminate received ambiguous pulse responses. By introducing a nonlinear operation on compressed (undesired) pulse responses within individual channels, ambiguous energy levels are reduced in channel outputs. This research expands the NLS concept using discrete …


Testing Exception And Error Cases Using Runtime Fault Injection, James A. Whittaker, Florence E. Mottay, Ibrahim K. El-Far Dec 2001

Testing Exception And Error Cases Using Runtime Fault Injection, James A. Whittaker, Florence E. Mottay, Ibrahim K. El-Far

Electrical Engineering and Computer Science Faculty Publications

Fault injection deals with the insertion or simulation of faults in order to test the robustness and fault tolerance of a software application. Such measures are generally performed on software that is mission critical, to the extent that failure could have significant negative ramifications. Actual injection of faults can be performed either at compile time, when additional code is inserted to force error conditions to evaluate to true, or at runtime during which faults are injected into the software's execution environment. This paper focuses on the latter type of fault injection and presents a new mechanism for inserting environmental faults. …


Hybrid Transient-Parametric Method And System To Distinguish And Analyze Sources Of Acoustic Emission For Nondestructive Inspection And Structural, Health Monitoring, Yuris Dzenis Dec 2001

Hybrid Transient-Parametric Method And System To Distinguish And Analyze Sources Of Acoustic Emission For Nondestructive Inspection And Structural, Health Monitoring, Yuris Dzenis

Department of Mechanical and Materials Engineering: Faculty Publications

A nondestructive evaluation (NDE) technique for inspecting or health monitoring of Structures and/or Specimens by analyzing acoustic emission (AE) signals emitted by the Structures and/or specimens. The method and System ana lyzes acoustic emission (AE) signals emitted by structures and/or Specimens. AE Signals emitted by the Structures and/or Specimens are parametrically filtered as a function of parametric filters corresponding to characteristic waveforms of transient AE classes of predefined AE signals. In para metric analysis, the filtering may be pre- or post-recording. In transient AE analysis, the filtering may be prior to transient recording of the transient signals.


Survivable Mobile Operating System, James Whittaker, Mohommad Samarah Dec 2001

Survivable Mobile Operating System, James Whittaker, Mohommad Samarah

Electrical Engineering and Computer Science Faculty Publications

Although there is a large body of work on cryptographic techniques and algorithms that provide basic building blocks to solve specific security problems, relatively little work has been done in investigating security issues in mobile system contexts. Conventional security controls work well for static code, but break down with code mobility. In this paper, we investigate the need for end-to-end security in mobile and wireless operating systems. We study the implications of mobility - specifically, ways in which the operating system may facilitate communication security. We suggest a framework for designing security into mobile devices by building encryption into the …


Ua3/9/5 Partnerships For Progress: Linking Higher Education & Economic Development, Wku President's Office, Gary A. Ransdell Dec 2001

Ua3/9/5 Partnerships For Progress: Linking Higher Education & Economic Development, Wku President's Office, Gary A. Ransdell

WKU Administration Documents

Speech delivered by WKU president Gary Ransdell at the National Governor's Association Center for Best Practices. In response to Governor Patton's challenges to create Programs of Distinction and enhance the state's capacity for economic development, we, at Western, have created a series of applied science centers. These centers are directing faculty talent toward creating a relevant curriculum in the sciences, toward solving environmental and material problems which limit economic development, and toward creating practice-based experiences for students. A by-product of these centers is a strengthened core curriculum which brings the applied sciences into focus for all WKU students.


Reduced Order Modeling For High Speed Flows With Moving Shocks, David J. Lucia Dec 2001

Reduced Order Modeling For High Speed Flows With Moving Shocks, David J. Lucia

Theses and Dissertations

The use of Proper Orthogonal Decomposition (POD) for reduced order modeling (ROM) of fluid problems is extended to high-speed compressible fluid flows. The challenge in using POD for high-speed flows is presented by the presence of moving discontinuities in the flow field. To overcome these difficulties, a domain decomposition approach is developed that isolates the region containing the moving shock wave for special treatment. The domain decomposition implementation produces internal boundaries between the various domain sections. The domains are linked using optimization-based solvers which employ constraints to ensure smoothness in overlapping portions of the internal boundary. This approach is applied …


Aisi Standard For Cold-Formed Steel Framing -- Header Design, American Iron And Steel Institute Dec 2001

Aisi Standard For Cold-Formed Steel Framing -- Header Design, American Iron And Steel Institute

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

The material contained herein has been developed by the American Iron and Steel Institute Committee on Framing Standards. The Committee has made a diligent effort to present accurate, reliable, and useful information on cold-formed steel framing design and installation. The Committee acknowledges and is grateful for the contributions of the numerous researchers, engineers, and others who have contributed to the body of knowledge on the subject. Specific references are included in the Header Standard document. With anticipated improvements in understanding of the behavior of cold-formed steel framing and the continuing development of new technology, this material may eventually become dated. …


Aisi Standard For Cold-Formed Steel Framing -- Truss Design, American Iron And Steel Institute Dec 2001

Aisi Standard For Cold-Formed Steel Framing -- Truss Design, American Iron And Steel Institute

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

The material contained herein has been developed by the American Iron and Steel Institute Committee on Framing Standards. The Committee has made a diligent effort to present accurate, reliable, and useful information on cold-formed steel framing design and installation. The Committee acknowledges and is grateful for the contributions of the numerous researchers, engineers, and others who have contributed to the body of knowledge on the subject. Specific references are included in the Truss Standard document. With anticipated improvements in understanding of the behavior of cold-formed steel framing and the continuing development of new technology, this material may eventually become dated. …


Acuta Enews December 2001, Vol.30, No. 12 Dec 2001

Acuta Enews December 2001, Vol.30, No. 12

ACUTA Newsletters

In This Issue

Michigan Tech Chooses Network Appliances

ACUTA Events

The "New Member Roundup"- Why It's Important

DC Update

ACUTA EVENTS

Mexico Dialing Pattern Change

Did the Lights Go Out? Events, Results, and Impacts

Board Report

Thanks to Our Sponsors!

Fourth Quarter 2001 Web Sites to See

Welcome New Members

Positions Available


Spectroscopic Ellipsometry And Electrical Studies Of As-Grown And Rapid Thermal Oxidized Si1−X−YGeXCY Films, W. K. Choi, W. Feng, L. K. Bera, Cary Y. Yang, J. Mi Dec 2001

Spectroscopic Ellipsometry And Electrical Studies Of As-Grown And Rapid Thermal Oxidized Si1−X−YGeXCY Films, W. K. Choi, W. Feng, L. K. Bera, Cary Y. Yang, J. Mi

Electrical and Computer Engineering

Transmission electron microscopy results showed the formation of SiC precipitation in a rapid thermally oxidized (RTO) Si1−x−yGexCy sample with high-C content. The spectroscopic ellipsometry results showed that the E1 gap increased and E2 gap decreased as the C concentration increased. For the oxidized samples, the amplitude of the E2 transitions reduced rapidly and the E1 transition shifted to a lower energy. The reduction in the E2 transitions was due to the presence of the oxide layer. A high-Ge content layer and the low-C content in the RTO films accounted for …


From Planning To Searching For The Shortest Plan: An Optimal Transition, Raul A. Trejo, Joel Galloway, Charanjiv Sachar, Vladik Kreinovich, Chitta Baral, Le Chi Tuan Dec 2001

From Planning To Searching For The Shortest Plan: An Optimal Transition, Raul A. Trejo, Joel Galloway, Charanjiv Sachar, Vladik Kreinovich, Chitta Baral, Le Chi Tuan

Departmental Technical Reports (CS)

Since Kautz and Selman's 1992 ECAI paper on satisfiability based planning, there has been several work on planning through finding models of a logical theory. Most of these works focus on finding a plan of a given length. If we want to find the shortest plan, then usually, we try plans of length 1, 2, ..., until we find the first length for which such a plan exists. When the planning problem is difficult and the shortest plan is of a reasonable length, this linear search can take a long time; to speed up the process, it has been proposed …


Statistics Of Sdf-System Estimate Of Roof Displacement For Pushover Analysis Of Buildings, Anil K. Chopra, Rakesh K. Goel, Chatpan Chintanapakdee Dec 2001

Statistics Of Sdf-System Estimate Of Roof Displacement For Pushover Analysis Of Buildings, Anil K. Chopra, Rakesh K. Goel, Chatpan Chintanapakdee

Civil and Environmental Engineering

Investigated in this report is the basic premise that the roof displacement of a multistory building can be determined from the deformation of an SDF system. For this purpose, the response of both systems is determined rigorously by nonlinear response history analysis, without introducing any of the approximations underlying the simplified methods for estimating the deformation of an SDF system (see, e.g., FEMA-273 or ATC-40 guidelines). The statistics of the SDF-system estimate of roof displacement are presented for a variety of building frames and six SAC buildings subjected to ground motion ensembles.

Two sets of structural systems and ground motions …


Determination Of Thickness Of Smooth Geomembranes, Nazli Yesiller, Arif Cekic Dec 2001

Determination Of Thickness Of Smooth Geomembranes, Nazli Yesiller, Arif Cekic

Civil and Environmental Engineering

Tests were conducted to determine thickness of smooth, nonreinforced geomembranes using three methods: mechanical (according to ASTM and European standards), ultrasonic, and magnetic methods. The mechanical method is the standard procedure used for determining thickness of geomembranes. The ultrasonic and magnetic methods are not commonly used for geomembranes; however, they are used for testing other materials such as metals. Tests were conducted on 15 geomembranes representing five types of polymers (HDPE, LLDPE, PVC, PP, and EPDM). The results of the testing program indicated that the level of pressures applied affected the thickness measurements in mechanical tests. While the low pressures …


Evaluation Of A Threshold-Based Model Of The Elevated-Temperature Fatique Of Impact-Damaged Γ-Tial, Trevor S. Harding, J. Wayne Jones Dec 2001

Evaluation Of A Threshold-Based Model Of The Elevated-Temperature Fatique Of Impact-Damaged Γ-Tial, Trevor S. Harding, J. Wayne Jones

Materials Engineering

Step-loading fatigue tests have been conducted on two γ-TiAl alloys with differing microstructures following quasi-static indentations intended to simulate assembly-related impact damage to low-pressure turbine blades. Fatigue tests were conducted at 600 °C using computer-controlled servohydraulic loading at a frequency of 20 Hz. Reasonably good agreement was achieved between the fatigue data and calculated fatigue strength based on the fatigue threshold and measured impact severity. In certain cases, the fatigue threshold model fails to completely describe the data. These discrepancies may be related to residual stresses, variations in crack-shape morphology, and small-crack effects. Residual stresses could not be directly measured, …


Evaluation Of Drip And Microsprayer Irrigation Systems In California's Central Valley, Charles M. Burt Dec 2001

Evaluation Of Drip And Microsprayer Irrigation Systems In California's Central Valley, Charles M. Burt

BioResource and Agricultural Engineering

No abstract provided.


Statistical And Dempster-Shafer Techniques In Testing Structural Integrity Of Aerospace Structures, Roberto A. Osegueda, Seetharami R. Seelam, Ana C. Holguin, Vladik Kreinovich, Chin-Wang Tao, Hung T. Nguyen Dec 2001

Statistical And Dempster-Shafer Techniques In Testing Structural Integrity Of Aerospace Structures, Roberto A. Osegueda, Seetharami R. Seelam, Ana C. Holguin, Vladik Kreinovich, Chin-Wang Tao, Hung T. Nguyen

Departmental Technical Reports (CS)

We describe the existing statistics-related methods of testing structural integrity for aerospace structures, describe their drawbacks, how they can be overcome, and compare the resulting techniques.


Techniques For The Regeneration Of Wideband Speech From Narrowband Speech, Jason A. Fuemmeler, Russell C. Hardie, William R. Gardner Dec 2001

Techniques For The Regeneration Of Wideband Speech From Narrowband Speech, Jason A. Fuemmeler, Russell C. Hardie, William R. Gardner

Electrical and Computer Engineering Faculty Publications

This paper addresses the problem of reconstructing wideband speech signals from observed narrowband speech signals. The goal of this work is to improve the perceived quality of speech signals which have been transmitted through narrowband channels or degraded during acquisition. We describe a system, based on linear predictive coding, for estimating wideband speech from narrowband. This system employs both previously identified and novel techniques. Experimental results are provided in order to illustrate the system’s ability to improve speech quality. Both objective and subjective criteria are used to evaluate the quality of the processed speech signals.


Accommodating Pedestrian And Bicycle Access On Parkers Mill Road From New Circle Road To Man O War Boulevard In Lexington, Lisa Aultman-Hall, Eric Jackson Dec 2001

Accommodating Pedestrian And Bicycle Access On Parkers Mill Road From New Circle Road To Man O War Boulevard In Lexington, Lisa Aultman-Hall, Eric Jackson

Kentucky Transportation Center Research Report

In the fall of 2000 the Kentucky Transportation Center (KTC) began a planning study on behalf of the Kentucky Transporta tion Cabinet (KYTC) to investigate the bicycle and pedestrian access on KY 1968 (Parkers Mill Road) from Man O War Boulevard to New Circle Road in Lexington. The 1-mile section has a rural design with two 9-foot lanes, limited 3-foot earth shoulders and adjacent objects in the clear zone making travel on this road uncomfortable for pedestrians and cyclists. Yet this section of Parkers Mill Road represents a line of desired non-motorized travel due to parks, neighborhoods, a local high …


Acoustic Emission For Periodic Inspection Of Composite Pressure Vessels, Bao Rasebolai Mosinyi Dec 2001

Acoustic Emission For Periodic Inspection Of Composite Pressure Vessels, Bao Rasebolai Mosinyi

Master's Theses - Daytona Beach

Cost savings can be achieved in a wide range of applications by replacing the current procedure for hydrostatic recertification of high-pressure composite gas cylinders with acoustic emission (AE) nondestructive testing. Advantages of AE recertification over the current hydrostatic method include: (1) no water contamination, since pressurization of the cylinders is done with air as opposed to water; (2) the risk of damage is decreased since the test pressure is reduced from 166% of design pressure to 110% of operating pressure; (3) the ability of acoustic emission to detect and locate flaws increases safety; and (4) the in-situ method will reduce …


Modeling And Analysis Of Social Networks, Robert S. Renfro Ii Dec 2001

Modeling And Analysis Of Social Networks, Robert S. Renfro Ii

Theses and Dissertations

This dissertation develops new methods for the modeling and analysis of social networks. Social networks describe the complex relationships of individuals and groups in multiple overlapping contexts. Influence in a social network impacts behavior and decision making in every setting in which individuals participate. This study defines a methodology for modeling and analyzing this complex behavior using a Flow-Model representation. Multiple objectives in an influencing effort targeted at a social network are modeled using Goal Programming. Value Focused Thinking is applied to model influence and predict decisions based on the reaction of the psychological state of individuals to environmental stimuli. …


Structural Studies Of Metastable Nanocrystalline Magnesium Titanate Ceramics, Renmei Xu Dec 2001

Structural Studies Of Metastable Nanocrystalline Magnesium Titanate Ceramics, Renmei Xu

Masters Theses

Nanocrystalline magnesium titanate powders were produced using alkoxides of magnesium and titanium for the sol-gel method. High temperature phases which can only be formed at above 1200°C in equilibrium were formed at much lower temperature 600°C in nanometric system. Cation ordering and structural changes in qandilite (Mg2TiO4 ), geikielite (MgTiO3 ) and karrooite (MgTi2O5 ) were studied by Rietveld refinement of neutron powder diffraction data and X-ray photoelectron spectroscopy. Single qandilite phases were obtained in a wide range of Mg:Ti ratios from 2:038:1 to 1.52:1, and appeared to be Mg2-xTi1+x …


Evaluation Of Automated Bridge Deck Anti-Icing System, Monica L. Barrett, Jerry G. Pigman Dec 2001

Evaluation Of Automated Bridge Deck Anti-Icing System, Monica L. Barrett, Jerry G. Pigman

Kentucky Transportation Center Research Report

Driving in snow and ice can be dangerous. This is especially true on bridges. Under certain cold weather conditions, moisture on bridge decks freeze because of the open air flow under them while the adjacent roadway is unaffected. This creates potentially hazardous driving situations for motorists who may not be expecting a change of condition from the road to the bridge surface.

To combat this problem, a bridge deck anti-icing system was installed on a bridge on southbound Interstate 75 at the north interchange to Corbin, Kentucky in October 1997. This system can be actuated early before ice and snow …


Construction Monitoring And Procedures For I-275 “Warranty Project”, Kenton/Boone Counties, Tim C. Scully Jr., R. Clark Graves, David L. Allen Dec 2001

Construction Monitoring And Procedures For I-275 “Warranty Project”, Kenton/Boone Counties, Tim C. Scully Jr., R. Clark Graves, David L. Allen

Kentucky Transportation Center Research Report

In the summer of 2000, it was decided by the Kentucky Transportation Cabinet that a portion of eastbound and westbound I-275 needed repair due to fatigue. The design was 10 inches PCC or 13 inches of asphaltic concrete for Section B, and 9 inches PCC or 12 inches of asphaltic concrete for Section A. Alternate bids were accepted from asphalt and concrete contractors with a required warranty of 10 years or 10,000,000 ESAL’s, which ever came first.

The Kentucky Transportation Center will be monitoring the performance of the pavement for the duration of the warranty and will be submitting an …


Improving Incident Management Response And Coordination Of Resources, Jennifer R. Walton, Monica L. Barrett, Jerry G. Pigman Dec 2001

Improving Incident Management Response And Coordination Of Resources, Jennifer R. Walton, Monica L. Barrett, Jerry G. Pigman

Kentucky Transportation Center Research Report

Highway crashes cause a major impact to the transportation network by critically limiting the operational efficiency of the roadway. Traveler delay is the problem most often associated with highway crashes, but by far the most serious problem is the resulting secondary crashes that occur. Another related issue is the danger posed to response personnel serving the public at the scene. The magnitude of these problems is severe. A coordinated plan for managing the scene is needed to reduce the impact of highway crashes and improve the safety for everyone.

A Checklist and interagency workshop has been developed to address ways …


Fiscal Year 2001 Fhwa-536 Report For The Kentucky Transportation Cabinet, Steven Douglas Kreis Dec 2001

Fiscal Year 2001 Fhwa-536 Report For The Kentucky Transportation Cabinet, Steven Douglas Kreis

Kentucky Transportation Center Research Report

The Federal Highway Administration (FHWA) requires state transportation agencies to submit a biennial report on local highway finances. The purpose of these reports is to provide FHWA with the data it needs to capture the financing of highway activities at the local level. Based on this information, it can identify trends in revenue, expenditures, investments, and program development, and in turn make decisions about future investments. The report, FHWA-536, asks agencies to report on four areas of local highway finance: 1) disposition of highway-user revenues; 2) revenues used for roads and streets identified by source and funding type; 3) road …


World Wide Web Resources For Materials Science, Serge Abrate Dec 2001

World Wide Web Resources For Materials Science, Serge Abrate

Mechanical and Aerospace Engineering Faculty Research & Creative Works

The internet makes technical information readily available in ways that were unthinkable a few years ago. This article shows how the World Wide Web (the web) can be used in a Materials Science class to enrich the educational process. Strategies for finding and evaluating information and are discussed. © 2002 Wiley Periodicals, Inc.


Multimedia Web-Based Resources For Engineering Education: The Media Design And Assessment Laboratory At Umr, Vicki M. Eller, Steve Eugene Watkins, Richard H. Hall, Joel Balestra, Asha S. Rao Dec 2001

Multimedia Web-Based Resources For Engineering Education: The Media Design And Assessment Laboratory At Umr, Vicki M. Eller, Steve Eugene Watkins, Richard H. Hall, Joel Balestra, Asha S. Rao

Business and Information Technology Faculty Research & Creative Works

The Design, Development, and Assessment of Web-Based Multimedia Learning Resources Are Important Aspects of Engineering Education. the Media Design and Assessment Laboratory at the University of Missouri-Rolla Was Established to Facilitate the Interaction between Web Designers and Content Providers. It Was Created under the Auspices of the Instructional Software Development Center. This Paper Will Discuss Design Philosophy in Terms of the Identification of Fundamental Concepts, Development Steps, and Assessment Implementation within the Context of Ongoing Projects. These Projects Include Modules for an Optics Curriculum, Tutorials for an Interdisciplinary Course, and Interactive Software for a Basic Engineering Course.


Power System Deregulation, Mariesa Crow Dec 2001

Power System Deregulation, Mariesa Crow

Electrical and Computer Engineering Faculty Research & Creative Works

Given the difficulties encountered by the state of California in deregulating their electric power industry, many people are questioning the wisdom of such a move. To better understand the motivation behind deregulation, the author looks at the cost of energy nationwide in the United States. For example, she considers some of the regional energy costs from August 2001.


Energy Storage Systems For Advanced Power Applications, Aysen Arsoy, Yilu Liu, Paul F. Ribeiro, Brian K. Johnson, Mariesa Crow Dec 2001

Energy Storage Systems For Advanced Power Applications, Aysen Arsoy, Yilu Liu, Paul F. Ribeiro, Brian K. Johnson, Mariesa Crow

Electrical and Computer Engineering Faculty Research & Creative Works

While energy storage technologies do not represent energy sources, they provide valuable added benefits to improve stability power quality, and reliability of supply. Battery technologies have improved significantly in order to meet the challenges of practical electric vehicles and utility applications. Flywheel technologies are now used in advanced nonpolluting uninterruptible power supplies. Advanced capacitors are being considered as energy storage for power quality applications. Superconducting energy storage systems are still in their prototype stages but receiving attention for utility applications. The latest technology developments, some performance analysis, and cost considerations are addressed. This paper concentrates on the performance benefits of …


A Theory Of Volumetric Growth For Compressible Elastic Biological Materials, Stephen M. Klisch, Timothy J. Van Dyke, Anne Hoger Dec 2001

A Theory Of Volumetric Growth For Compressible Elastic Biological Materials, Stephen M. Klisch, Timothy J. Van Dyke, Anne Hoger

Mechanical Engineering

A general theory of volumetric growth for compressible elastic materials is presented. The authors derive a complete set of governing equations in the present configuration for an elastic material undergoing a continuous growth process. In particular, they obtain two constitutive restrictions from a work-energy principle. First, the authors show that a growing elastic material behaves as a Green-elastic material. Second, they obtain an expression that relates the stress power due to growth to the rate of energy change due to growth. Then, the governing equations for a small increment of growth are derived from the more general theory. The equations …