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2005

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Articles 2461 - 2490 of 3074

Full-Text Articles in Engineering

Finite Element Evaluation Of The Effects Of Lateral Anchorage Strips On The Behavior Of Cfrp-Strengthened Rc Beams, Jose Javier Perez Jan 2005

Finite Element Evaluation Of The Effects Of Lateral Anchorage Strips On The Behavior Of Cfrp-Strengthened Rc Beams, Jose Javier Perez

Electronic Theses and Dissertations

In this thesis, a fully nonlinear finite element study of the flexural behavior of doubly reinforced concrete beams strengthened using different Carbon Fiber Reinforced Polymer (CFRP) composite strengthening configurations has been carried out. Prior to the study, a total of six beams were constructed, pre-cracked, strengthened and tested to failure under a four-point loading condition (Zhao and O'Riordan-Adjah, 2004). Then, for the purpose of this thesis work, detailed three dimensional finite element models were created not only to correlate the results obtained from the experiments, but also to predict the load capacity, failure modes and crack pattern of reinforced concrete …

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Planning And Scheduling For Large-Scaledistributed Systems, Han Yu Jan 2005

Planning And Scheduling For Large-Scaledistributed Systems, Han Yu

Electronic Theses and Dissertations

Many applications require computing resources well beyond those available on any single system. Simulations of atomic and subatomic systems with application to material science, computations related to study of natural sciences, and computer-aided design are examples of applications that can benefit from the resource-rich environment provided by a large collection of autonomous systems interconnected by high-speed networks. To transform such a collection of systems into a user's virtual machine, we have to develop new algorithms for coordination, planning, scheduling, resource discovery, and other functions that can be automated. Then we can develop societal services based upon these algorithms, which hide …

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Studies Of Liquid Crystal Response Time, Haiying Wang Jan 2005

Studies Of Liquid Crystal Response Time, Haiying Wang

Electronic Theses and Dissertations

In this dissertation, the response time issue of the liquid crystal (LC) devices is investigated in meeting the challenges for display and photonic applications. The correlation between the LC director response time and the optical response time is derived theoretically and confirmed experimentally. A major contribution of this thesis is that, based on the small angle approximation, we derive rigorous analytical solutions for correlating the LC director response time to its consequent optical response times (both rise and decay) of a vertical-aligned nematic LC cell. This work successfully fills the gap in the literature of LCD switching dynamics. An important …

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Graph-Theoretic Approach To Modeling Propagation And Control Of Network Worms, Zoran Nikoloski Jan 2005

Graph-Theoretic Approach To Modeling Propagation And Control Of Network Worms, Zoran Nikoloski

Electronic Theses and Dissertations

In today's network-dependent society, cyber attacks with network worms have become the predominant threat to confidentiality, integrity, and availability of network computing resources. Despite ongoing research efforts, there is still no comprehensive network-security solution aimed at controling large-scale worm propagation. The aim of this work is fivefold: (1) Developing an accurate combinatorial model of worm propagation that can facilitate the analysis of worm control strategies, (2) Building an accurate epidemiological model for the propagation of a worm employing local strategies, (3) Devising distributed architecture and algorithms for detection of worm scanning activities, (4) Designing effective control strategies against the worm, …

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The Effect Of Tidal Inlets On Open Coast Storm Surge Hydrographs: A Case Study Of Hurricane Ivan (2004), Michael Salisbury Jan 2005

The Effect Of Tidal Inlets On Open Coast Storm Surge Hydrographs: A Case Study Of Hurricane Ivan (2004), Michael Salisbury

Electronic Theses and Dissertations

Florida's Department of Transportation requires design storm tide hydrographs for coastal waters surrounding tidal inlets along the coast of Florida. These hydrographs are used as open ocean boundary conditions for local bridge scour models. At present, very little information is available on the effect that tidal inlets have on these open coast storm tide hydrographs. Furthermore, current modeling practice enforces a single design hydrograph along the open coast boundary for bridge scour models. This thesis expands on these concepts and provides a more fundamental understanding on both of these modeling areas. A numerical parameter study is undertaken to elucidate the …

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Super High-Speed Miniaturized Permanent Magnet Synchronous Motor, Liping Zheng Jan 2005

Super High-Speed Miniaturized Permanent Magnet Synchronous Motor, Liping Zheng

Electronic Theses and Dissertations

This dissertation is concerned with the design of permanent magnet synchronous motors (PMSM) to operate at super-high speed with high efficiency. The designed and fabricated PMSM was successfully tested to run upto 210,000 rpm The designed PMSM has 2000 W shaft output power at 200,000 rpm and at the cryogenic temperature of 77 K. The test results showed the motor to have an efficiency reaching above 92%. This achieved efficiency indicated a significant improvement compared to commercial motors with similar ratings. This dissertation first discusses the basic concept of electrical machines. After that, the modeling of PMSM for dynamic simulation …

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Adapting The Modified Cam Clay Constitutive Model To The Computational Analysis Of Dense Granular Soils, Jose Arvelo Jan 2005

Adapting The Modified Cam Clay Constitutive Model To The Computational Analysis Of Dense Granular Soils, Jose Arvelo

Electronic Theses and Dissertations

The computational constitutive Modified Cam Clay Model (MCCM) was developed at Cambridge to study the behavior of clays and has been proven to be effective. In this study, this model is extended to the case of dense sands to analyze the accuracy of the stress-strain behavior. This analysis is based on triaxial test data applied to remolded and compacted sand samples under drained conditions. The laboratory triaxial tests were performed by the Florida Department of Transportation to research the permeability effect in sandy soils compacted up to 95% of maximum unit weight at the optimum moisture content. Each soil sample …

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Contributions To Automatic Particle Identification In Electron Micrographs: Algorithms, Implementation, And Applications, Vivek Singh Jan 2005

Contributions To Automatic Particle Identification In Electron Micrographs: Algorithms, Implementation, And Applications, Vivek Singh

Electronic Theses and Dissertations

Three dimensional reconstruction of large macromolecules like viruses at resolutions below 8 Ã… - 10 Ã… requires a large set of projection images and the particle identification step becomes a bottleneck. Several automatic and semi-automatic particle detection algorithms have been developed along the years. We present a general technique designed to automatically identify the projection images of particles. The method utilizes Markov random field modelling of the projected images and involves a preprocessing of electron micrographs followed by image segmentation and post processing for boxing of the particle projections. Due to the typically extensive computational requirements for extracting hundreds of …

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Multizoom Activity Recognition Using Machine Learning, Raymond Smith Jan 2005

Multizoom Activity Recognition Using Machine Learning, Raymond Smith

Electronic Theses and Dissertations

In this thesis we present a system for detection of events in video. First a multiview approach to automatically detect and track heads and hands in a scene is described. Then, by making use of epipolar, spatial, trajectory, and appearance constraints, objects are labeled consistently across cameras (zooms). Finally, we demonstrate a new machine learning paradigm, TemporalBoost, that can recognize events in video. One aspect of any machine learning algorithm is in the feature set used. The approach taken here is to build a large set of activity features, though TemporalBoost itself is able to work with any feature set …

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Vibration Analysis Of Carbon Nanotube Using Continuum Model And Finite Element Model, Hari Subramaniam Jan 2005

Vibration Analysis Of Carbon Nanotube Using Continuum Model And Finite Element Model, Hari Subramaniam

Electronic Theses and Dissertations

The main objective of the thesis is to propose the methods of determining vibration behavior of carbon nanotubes (CNTs) using continuum models and finite element models. Secondary objective is to find the effect of van der Waals force on vibration of multiwalled carbon nanotubes . The study of vibration behavior of CNTs is important because of their potential engineering applications such as nano-mechanical resonators and tips of scanning probe instruments where they are subjected to mechanical vibrations. Continuum modeling is based on an elastic beam model. The interlayer van der Waals interactions are represented by Lennard-Jones potential. In finite element …

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Rr Interval Estimation From An Ecg Using A Linear Discrete Kalman Filter, Arun Janapala Jan 2005

Rr Interval Estimation From An Ecg Using A Linear Discrete Kalman Filter, Arun Janapala

Electronic Theses and Dissertations

An electrocardiogram (ECG) is used to monitor the activity of the heart. The human heart beats seventy times on an average per minute. The rate at which a human heart beats can exhibit a periodic variation. This is known as heart rate variability (HRV). Heart rate variability is an important measurement that can predict the survival after a heart attack. Studies have shown that reduced HRV predicts sudden death in patients with Myocardial Infarction (MI). The time interval between each beat is called an RR interval, where the heart rate is given by the reciprocal of the RR interval expressed …

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Speedes: A Case Study Of Space Operations, Amith Paruchuri Jan 2005

Speedes: A Case Study Of Space Operations, Amith Paruchuri

Electronic Theses and Dissertations

This thesis describes the application of parallel simulation techniques to represent the structured functional parallelism present within the Space Shuttle Operations Flow using the Synchronous Parallel Environment for Emulation and Discrete-Event Simulation (SPEEDES), an object-oriented multi-computing architecture. SPEEDES is a unified parallel simulation environment, which allocates events over multiple processors to get simulation speed up. Its optimistic processing capability minimizes simulation lag time behind wall clock time, or multiples of real-time. SPEEDES accommodates an increase in process complexity with additional parallel computing nodes to allow sharing of processing loads. This thesis focuses on the process of translating a model of …

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Oceanic Rain Identification Using Multifractal Analysis Of Quikscat Sigma-0, Vasud Ganesh Torsekar Jan 2005

Oceanic Rain Identification Using Multifractal Analysis Of Quikscat Sigma-0, Vasud Ganesh Torsekar

Electronic Theses and Dissertations

The presence of rain over oceans interferes with the measurement of sea surface wind speed and direction from the Sea Winds scatterometer and as a result wind measurements contain biases in rain regions. In past research at the Central Florida Remote Sensing Lab, it has been observed that rain has multi-fractal behavior. In this report we present an algorithm to detect the presence of rain so that rain regions are flagged. The forward and aft views of the horizontal polarization σ0 are used for the extraction of textural information with the help of multi-fractals. A single negated multi-fractal exponent is …

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Effects Of Transport Properties And Flame Unsteadiness On Nitrogen Oxides Emissions From Laminar Hydrogen Jet Diffusion Flames, Doyoub Park Jan 2005

Effects Of Transport Properties And Flame Unsteadiness On Nitrogen Oxides Emissions From Laminar Hydrogen Jet Diffusion Flames, Doyoub Park

Electronic Theses and Dissertations

Experimental studies on the coupled effects of transport properties and unsteady fluid dynamics have been conducted on laminar, acoustically forced, hydrogen jet diffusion flames diluted by argon and helium. The primary purpose of this research is to determine how the fuel Lewis number and the flow unsteadiness play a combined role in maximum flame temperature and affect NOx emission from jet diffusion flame. The fuel Lewis number is varied by increasing/decreasing the mole fraction of diluents in the fuel stream. Therefore, maximum flame temperatures and then NOx emission levels were expected to differ for Ar- and He-diluted flames. In an …

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Structural Condition Assessment Of Prestressed Concrete Transit Guideways, Robert Zachary Shmerling Jan 2005

Structural Condition Assessment Of Prestressed Concrete Transit Guideways, Robert Zachary Shmerling

Electronic Theses and Dissertations

Objective condition assessment is essential to make better decisions for safety and serviceability of existing civil infrastructure systems. This study explores the condition of an existing transit guideway system that has been in service for thirty-five years. The structural system is composed of six-span continuous prestressed concrete bridge segments. The overall transit system incorporates a number of continuous bridges which share common design details, geometries, and loading conditions. The original analysis is based on certain simplifying assumptions such as rigid behavior over supports and simplified tendon/concrete/steel plate interaction. The current objective is to conduct a representative study for a more …

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Right Turn Split: A New Design To Alleviate Weaving On Arterial Streets, Khaled Shaaban Jan 2005

Right Turn Split: A New Design To Alleviate Weaving On Arterial Streets, Khaled Shaaban

Electronic Theses and Dissertations

While weaving maneuvers occur on every type of roadway, most studies have focused on freeway maneuvers. Weaving occurring on non-freeway facilities, such as arterial streets, can cause significant operational problems. Arterial streets weaving typically occur when vehicles coming from a side street at an upstream intersection attempt to enter the main street from one side to reach access points on the opposite site at a downstream intersection by crossing one or more lanes. This dissertation investigates the type of problems occurring on arterial streets due to the weaving movements and recommends a new design to alleviate weaving on arterial streets. …

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Automobiles And Auto Manufacturing, John Alfred Heitmann Jan 2005

Automobiles And Auto Manufacturing, John Alfred Heitmann

History Faculty Publications

In several important respects the automobile and automobile manufacturing proved to be at the heart of North American life during the 1950s. The decade was one characterized as the age of tail fins and chrome, and the automobile was recognized as something far more than ordinary transportation.

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Mining Picmet: 1997-2005 Papers Help You Track Management Of Technology Developments, Alan L. Porter, Robert J. Watts, Timothy R. Anderson Jan 2005

Mining Picmet: 1997-2005 Papers Help You Track Management Of Technology Developments, Alan L. Porter, Robert J. Watts, Timothy R. Anderson

Engineering and Technology Management Faculty Publications and Presentations

PICMET is providing the abstracts from 1997 -- 2005 to enable you to "mine" the contents of these four conferences. This enables you to overview activity in the field of Management of Technology (MOT) and to identify specific research of interest.

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Measuring The Changing Capabilities Of Computer Display Projectors Using Tfdea, Supachart Iamratanakul, Timothy R. Anderson, Lane Inman Jan 2005

Measuring The Changing Capabilities Of Computer Display Projectors Using Tfdea, Supachart Iamratanakul, Timothy R. Anderson, Lane Inman

Engineering and Technology Management Faculty Publications and Presentations

This paper applies technological forecasting using data envelopment analysis (TFDEA) to computer display projector (CDP) technology. The objective is to analyze the technological change CDP products. The results indicate that the rate of technological change for CDP technology is accelerating, which is consistent with an understanding of the industry. A methodological issue of infeasibility is described and methods for dealing with it are presented. Future work may extend to examine over additional years and product releases.

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Flexibility – Examining An Underappreciated Motivation For Outsourcing With An Optimization Model In A Small E-Product Manufacturer, Asser Fayed, Timothy R. Anderson, David Fenwick Jan 2005

Flexibility – Examining An Underappreciated Motivation For Outsourcing With An Optimization Model In A Small E-Product Manufacturer, Asser Fayed, Timothy R. Anderson, David Fenwick

Engineering and Technology Management Faculty Publications and Presentations

Technology outsourcing has recently become a politically sensitive issue with proponents emphasizing longterm economic growth opportunities, and opponents pointing out immediate job losses. The underlying reason for outsourcing is often assumed to be the availability of cheaper labor outside the USA but this overlooks the possibility that companies may simply be seeking greater labor flexibility outside of US state and federal labor laws. This paper quantitatively tests a software company’s motivation to secure a flexible and adaptable labor pool. Although production lines located at multiple sites provide great flexibility for scheduling and costs because each site has its own local …

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Calibration And Compensation Of Near-Field Scan Measurements, Masahiro Yamaguchi, Richard E. Dubroff, Kevin P. Slattery, Michael A. Cracraft, Jin Shi Jan 2005

Calibration And Compensation Of Near-Field Scan Measurements, Masahiro Yamaguchi, Richard E. Dubroff, Kevin P. Slattery, Michael A. Cracraft, Jin Shi

Electrical and Computer Engineering Faculty Research & Creative Works

A procedure for the calibration and compensation of near-field scanning is described and demonstrated. Ultimately, the objective is to quantify the individual field components associated with electromagnetic interference (EMI) from high speed circuitry and devices. Specific examples of these methods are shown. The effects of compensation are small but noticeable when the uncompensated output signal from near field scanning is already a very good representation of the field being measured. In other cases, the improvement provided by compensation can be significant when the uncompensated output signal bears little resemblance to the underlying field.

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Performance Of A Bgo Pet/Ct With Higher Resolution Pet Detectors, John W. Wilson, Timothy G. Turkington, J. J. Williams, James G. Colsher, D. L. Mcdaniel, C. L. Kim, Steven G. Ross, C. W. Stearns, S. D. Wollenweber Jan 2005

Performance Of A Bgo Pet/Ct With Higher Resolution Pet Detectors, John W. Wilson, Timothy G. Turkington, J. J. Williams, James G. Colsher, D. L. Mcdaniel, C. L. Kim, Steven G. Ross, C. W. Stearns, S. D. Wollenweber

Mining Engineering Faculty Research & Creative Works

A new PET detector block has been designed to replace the standard detector of the Discovery ST PET/CT system. The new detector block is the same size as the original, but consists of an 8/spl times/6 (tangential× axial) matrix of crystals rather than the original 6/spl times/6. The new crystal dimensions are 4.7× 6.3× 30 mm/sup 3/ (tangential× axial× radial). Full PET/CT systems have been built with these detectors (Discovery STE). Most other aspects of the system are identical to the standard Discovery ST, with differences including the low energy threshold for 3D imaging (now 425 keV) and front-end electronics. …

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Pulsed Charging Of Capacitor Bank By Compact Explosive-Driven High-Voltage Primary Power Source Based On Longitudinal Shock Wave Depolarization Of Ferroelectric Ceramics, Sergey I. Shkuratov, Jason Baird, Evgueni F. Talantsev, Yaroslav Tkach, Larry L. Altgilbers, Allen H. Stults, Stanislav V. Kolossenok Jan 2005

Pulsed Charging Of Capacitor Bank By Compact Explosive-Driven High-Voltage Primary Power Source Based On Longitudinal Shock Wave Depolarization Of Ferroelectric Ceramics, Sergey I. Shkuratov, Jason Baird, Evgueni F. Talantsev, Yaroslav Tkach, Larry L. Altgilbers, Allen H. Stults, Stanislav V. Kolossenok

Mining Engineering Faculty Research & Creative Works

Results of the investigation of the operation of autonomous ultracompact explosive-driven high-voltage primary power sources based on longitudinal (when the shock wave propagates along the polarization vector P0) shock wave depolarization of ferroelectric materials in the open circuit and charging modes are presented. The energy-carrying elements of shock wave ferroelectric generators (FEGs) were poled lead zirconate titanate (PZT) Pb(Zr52Ti48)O3 polycrystalline piezoelectric ceramic disks with volume 0.35 cm3. The PZT modules were shock compressed in the stress range from 1.5 to 3.8 GPa by a longitudinal shock wave generated by high explosives. In the charging mode, the FEGs provided pulsed power …

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Molecular Dynamics Simulations Of Biological Membranes In The Presence Of Cryoprotectants, Dinesh Pinisetty Jan 2005

Molecular Dynamics Simulations Of Biological Membranes In The Presence Of Cryoprotectants, Dinesh Pinisetty

LSU Master's Theses

Cryopreservation is a process that is characterized by the transport of water and cryoprotectants through the cell membrane. This phenomenon has been studied in extensive detail at the macroscopic (µm) scale but in a somewhat more limited fashion at the microscopic (nm) scale. In this study we develop several lipid bilayer models to approximate a cell membrane (nm) and present the effect of several different cryoprotectants on the structural characteristics of these lipid bilayers using molecular dynamic simulations. The lipid bilayer models included dipalmitoylphosphatidylcholine (DPPC), dimyristoylphosphatidylcholine (DMPC) and palmitoyleylphosphatidylcholine (POPC) while the cryoprotectants included methanol and dimethylsulfoxide (DMSO). The molecular …

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Nebraska Summary: S549 Challenger Mt555b, Nebraska Tractor Test Lab Jan 2005

Nebraska Summary: S549 Challenger Mt555b, Nebraska Tractor Test Lab

Nebraska Tractor Tests

ABOUT THE TEST REPORT AND USE OF THE DATA The test data contained in this report are a tabulation of the results of a series of tests. Due to the restricted format of these pages, only a limited amount of data and not all of the tractor specifications are included. The full OECD report contains usually about 30 pages of data and specifications. The test data were obtained for each tractor under similar conditions and therefore, provide a means of comparison of performance based on a limited set of reported data. EXPLANATION OF THE TEST PROCEDURES Purpose The purpose of …

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Nebraska Summary: S530 Case-Ih Jx1090u, Nebraska Tractor Test Lab Jan 2005

Nebraska Summary: S530 Case-Ih Jx1090u, Nebraska Tractor Test Lab

Nebraska Tractor Tests

ABOUT THE TEST REPORT AND USE OF THE DATA The test data contained in this report are a tabulation of the results of a series of tests. Due to the restricted format of these pages, only a limited amount of data and not all of the tractor specifications are included. The full OECD report contains usually about 30 pages of data and specifications. The test data were obtained for each tractor under similar conditions and therefore, provide a means of comparison of performance based on a limited set of reported data. EXPLANATION OF THE TEST PROCEDURES Purpose The purpose of …

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Test 2242: Case Ih Mxu100 Diesel, Nebraska Tractor Test Lab Jan 2005

Test 2242: Case Ih Mxu100 Diesel, Nebraska Tractor Test Lab

Nebraska Tractor Tests

No abstract provided.

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Test 2245: Case Ih Mxu110 Diesel, Nebraska Tractor Test Lab Jan 2005

Test 2245: Case Ih Mxu110 Diesel, Nebraska Tractor Test Lab

Nebraska Tractor Tests

No abstract provided.

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Test 2241: New Holland Ts100a Diesel, Nebraska Tractor Test Lab Jan 2005

Test 2241: New Holland Ts100a Diesel, Nebraska Tractor Test Lab

Nebraska Tractor Tests

No abstract provided.

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Tests 2307 & 2308: Challenger Mt565b Autopower Iv Diesel, Nebraska Tractor Test Lab Jan 2005

Tests 2307 & 2308: Challenger Mt565b Autopower Iv Diesel, Nebraska Tractor Test Lab

Nebraska Tractor Tests

No abstract provided.

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