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2004

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Articles 931 - 960 of 4447

Full-Text Articles in Physical Sciences and Mathematics

Innovative Application Of Fuzzy Logic To Conceptual Design Evaluation, Caroline Lubert, D. Verma Aug 2004

Innovative Application Of Fuzzy Logic To Conceptual Design Evaluation, Caroline Lubert, D. Verma

Caroline P Lubert

No abstract provided.


Performance Property Theories For Predictable Assembly From Certifiable Components (Pacc), Scott A. Hissam, Mark H. Klein, John Lehoczky, Paulo Merson, Gabriel A. Moreno, Kurt C. Wallnau Aug 2004

Performance Property Theories For Predictable Assembly From Certifiable Components (Pacc), Scott A. Hissam, Mark H. Klein, John Lehoczky, Paulo Merson, Gabriel A. Moreno, Kurt C. Wallnau

Gabriel A. Moreno

This report develops a queueing-theoretic solution to predict, for a real-time system, the average-case latency of aperiodic tasks managed by a sporadic server. The report applies this theory to a model problem drawn in the domain of industrial robot control. In this model problem, a controller with hard periodic deadlines is “open” to third-party plug-in extensions. The sporadic server is used to limit the invasiveness of aperiodic tasks on the controller’s hard deadlines. The theory developed in this report is used to predict the average- case latency of a plug-in managed by a sporadic server.


A Transport Layer For Live Streaming In A Content Delivery Network, Leonidas Kontothanassis, Ramesh Sitaraman, Joel Wein, Duke Hong, Robert Kleinberg, Brian Mancuso, David Shaw, Daniel Stodolsky Aug 2004

A Transport Layer For Live Streaming In A Content Delivery Network, Leonidas Kontothanassis, Ramesh Sitaraman, Joel Wein, Duke Hong, Robert Kleinberg, Brian Mancuso, David Shaw, Daniel Stodolsky

Ramesh Sitaraman

Streaming media on the internet has experienced rapid growth over the last few years and will continue to increase in importance as broadband technologies and authoring tools continue to improve. As the internet becomes an increasingly popular alternative to traditional communications media, internet streaming will become a significant component of many content providers’ communications strategy. Internet streaming, however, poses significant challenges for content providers since it has significant distribution problems. Scalability, quality, reliability, and cost are all issues that have to be addressed in a successful streaming media offering. Streaming Content Delivery Networks attempt to provide solutions to the bottlenecks …


Amplification Of Electrostatic Ion-Cyclotron Waves In A Plasma With Magnetic-Field-Aligned Ion Flow Shear And No Electric Current, Erick Agrimson Aug 2004

Amplification Of Electrostatic Ion-Cyclotron Waves In A Plasma With Magnetic-Field-Aligned Ion Flow Shear And No Electric Current, Erick Agrimson

Erick Agrimson

No abstract provided.


Pitchfork Bifurcations Of Invariant Manifolds, Jyoti Champanerkar Aug 2004

Pitchfork Bifurcations Of Invariant Manifolds, Jyoti Champanerkar

Dissertations

In a parameter dependent, dynamical system, when the qualitative structure of the solutions changes due to a small change in the parameter, the system is said to have undergone a bifurcation. Bifurcations have been classified on the basis of the topological properties of fixed points and invariant manifolds of dynamical systems. A pitchfork bifurcation in R is said to have occurred when a stable fixed point becomes unstable and two new stable fixed points, separated by the unstable fixed point come into existence.

In this thesis, a pitchfork bifurcation of an (in- 1)-dimensional invariant submani-fold of a dynamical system in …


Numerical Simulation Of Microwave Heating Of A Target With Temperature Dependent Electrical Properties In A Single-Mode Cavity, Hoa Kien Tran Aug 2004

Numerical Simulation Of Microwave Heating Of A Target With Temperature Dependent Electrical Properties In A Single-Mode Cavity, Hoa Kien Tran

Dissertations

This dissertation extends the work done by Hue and Kriegsmann in 1998 on microwave heating of a ceramic sample in a single-mode waveguide cavity. In that work, they devised a method combining asymptotic and numerical techniques to speed up the computation of electromagnetic fields inside a high-Q cavity in the presence of low-loss target. In our problem, the dependence of the electrical conductivity on temperature increases the complexity of the problem. Because the electrical conductivity depends on temperature, the electromagnetic fields must be recomputed as the temperature varies. We then solve the coupled heat equation and Maxwell's equations to determine …


Modeling Usage Of An Online Research Community, Yi Zhang Aug 2004

Modeling Usage Of An Online Research Community, Yi Zhang

Dissertations

Although online communities have been thought of as a new way for collaboration across geographic boundaries in the scientific world, they have a problem attracting people to keep visiting. The main purpose of this study is to understand how people behave in such communities, and to build and evaluate tools to stimulate engagement in a research community. These tools were designed based on a research framework of factors that influence online participation and relationship development.

There are two main objectives for people to join an online community, information sharing and interpersonal relationship development, such as friends or colleagues. The tools …


Toxicity Of Manufactured Particulate Materials On Plant Root Growth, Ling Yang Aug 2004

Toxicity Of Manufactured Particulate Materials On Plant Root Growth, Ling Yang

Dissertations

The rapid development of particle technology and the growing use of particulate materials in industries are bringing large amounts of manufactured particles into the environment. Epidemiological studies suggest that fine particles (particles with aerodynamic diameter smaller than 2.5 μm, i.e., PM2.5) have an association with various adverse health effects in humans. Mass studies have been performed on the toxicity and toxicological mechanisms of airborne particles such as PM2.5 and PM10, but there are very few investigations which contribute to the knowledge base on biological implications of manufactured particulate materials. Up to now, the published toxicity …


The Adjoint Of An Even Size Matrix Factors, Ragnar-Olaf Buchweitz, Graham J. Leuschke Aug 2004

The Adjoint Of An Even Size Matrix Factors, Ragnar-Olaf Buchweitz, Graham J. Leuschke

Mathematics - All Scholarship

We show that the adjoint matrix of a generic square matrix of even size can be factored nontrivially, answering a question of G. Bergman. This note is a preliminary report on work in progress.


A Scalable And Oblivious Digital Watermarking For Images, W. Lu, R. Safavi-Naini, Takeyuki Uehara, Wanqing Li Aug 2004

A Scalable And Oblivious Digital Watermarking For Images, W. Lu, R. Safavi-Naini, Takeyuki Uehara, Wanqing Li

Faculty of Informatics - Papers (Archive)

Scalable compression algorithms, such as JPEG, can compress images to different quality or resolution levels so that the target systems with different display capabilities, can display the image. Digital watermarking is widely used for protection of copyright and identification of ownership on digital images. It is desirable to have scalable watermarking systems, where the watermark is detectable when the watermarked image is at low quality or low resolution levels. This paper presents an oblivious block-based spread-spectrum-like watermarking system which is robust against scalable JPEG compression, cropping and shifting. The system is secure against the common watermarking attacks. Experimental results support …


A Semi-Supervised Map Segmentation Of Brain Tissues, Wanqing Li, C. Desilver, Y. Attikiouzel Aug 2004

A Semi-Supervised Map Segmentation Of Brain Tissues, Wanqing Li, C. Desilver, Y. Attikiouzel

Faculty of Informatics - Papers (Archive)

This paper presents a method for semi-supervised MAP (maximum a-posterior probability) segmentation of brain tissues where labelled data are available for either all types of tissues or only a few types of tissues possibly at different levels of quality. The proposed MAP segmentation takes supervised and unsupervised segmentation as its two special cases where, respectively, quality labelled data is available or there is no labelled data at all. Experiments on real MR images have shown that the proposed method improved the segmentation accuracy substantially with only a few labelled data in comparison with both fully supervised method with the same …


Significance Analysis Of Time Course Microarray Experiments, John D. Storey, Wenzhong Xiao, Jeffrey T. Leek, Ronald G. Tompkins, Ron W. Davis Aug 2004

Significance Analysis Of Time Course Microarray Experiments, John D. Storey, Wenzhong Xiao, Jeffrey T. Leek, Ronald G. Tompkins, Ron W. Davis

UW Biostatistics Working Paper Series

Characterizing the genome-wide dynamic regulation of gene expression is important and will be of much interest in the future. However, there is currently no established method for identifying differentially expressed genes in a time course study. Here we propose a significance method for analyzing time course microarray studies that can be applied to the typical types of comparisons and sampling schemes. This method is applied to two studies on humans. In one study, genes are identified that show differential expression over time in response to in vivo endotoxin administration. Using our method 7409 genes are called significant at a 1% …


An Ecological Display For Robot Teleoperation, Robert W. Ricks Aug 2004

An Ecological Display For Robot Teleoperation, Robert W. Ricks

Theses and Dissertations

This thesis presents an interface for effectively teleoperating robots that combines an ecological display of range and video information with quickening based on dead-reckoning prediction. This display is built by viewing range and video information from a virtual camera trailing the robot. This is rendered in 3-D by using standard hardware acceleration and 3-D graphics software. Our studies demonstrate that this interface improves performance for most people, including those that do not have much previous experience with robotics. These studies involved 32 test subjects in a simulated environment and 8 in the real world. Subjects were required to drive the …


Education In The Environment: A Hands-On Student Research And Outdoor Learning Experience: Quarterly Progress Report, Period Ending August 31, 2004, Environmental Education Strategy For Nevada Aug 2004

Education In The Environment: A Hands-On Student Research And Outdoor Learning Experience: Quarterly Progress Report, Period Ending August 31, 2004, Environmental Education Strategy For Nevada

Reports (PLI Education)

In the first three months of this agreement, UNLV has met with the Outside Las Vegas Environmental Education Committee to establish the duties of and create detailed job announcements for the project managers for the Environmental Education Strategy and for the Forever Earth/WOW Program. Although the university had planned to meet with the committee at its June meeting, that meeting was cancelled due to summer scheduling conflicts among the committee members. Subsequently, Dr. Peg Rees and Nancy Flagg met with the committee on July 14,2004. The committee was brought up-to-date on goals and deliverables of the task agreement, UNLV’s role …


Modeling Corrosion In Oxygen Controlled Lbe Systems With Coupling Of Chemical Kinetics And Hydrodynamics-Task V: Trp Final Report 09/01/2003-08/31/2004, Samir Moujaes, Yitung Chen Aug 2004

Modeling Corrosion In Oxygen Controlled Lbe Systems With Coupling Of Chemical Kinetics And Hydrodynamics-Task V: Trp Final Report 09/01/2003-08/31/2004, Samir Moujaes, Yitung Chen

Transmutation Sciences Materials (TRP)

The Lead-Bismuth eutectic (LBE) has been determined from previous experimental studies by the Russians and the European scientific community to be a potential material that can be used as a spallation target and coolant for the TRP proposed application. Properly controlling the oxygen content in LBE can drastically reduce the LBE corrosion to structural steels. However, existing knowledge of material corrosion performance was obtained from point-wise testing with only very sparse experimental data. Scientists have noticed that the concentration of oxygen dissolved in the liquid alloy could control the corrosion rate of steels exposed to Pb or Pb-Bi. At high …


Modeling Corrosion In Oxygen Controlled Lbe Systems With Coupling Of Chemical Kinetics And Hydrodynamics-Task V: Fourth Quarterly Report 06/01/2004-08/31/2004, Samir Moujaes, Yitung Chen Aug 2004

Modeling Corrosion In Oxygen Controlled Lbe Systems With Coupling Of Chemical Kinetics And Hydrodynamics-Task V: Fourth Quarterly Report 06/01/2004-08/31/2004, Samir Moujaes, Yitung Chen

Transmutation Sciences Materials (TRP)

The Lead-Bismuth eutectic (LBE) has been determined from previous experimental studies by the Russians and the European scientific community to be a potential material that can be used as a spallation target and coolant for the TRP proposed application. Properly controlling the oxygen content in LBE can drastically reduce the LBE corrosion to structural steels. However, existing knowledge of material corrosion performance was obtained from point-wise testing with only very sparse experimental data. Scientists have noticed that the concentration of oxygen dissolved in the liquid alloy could control the corrosion rate of steels exposed to Pb or Pb-Bi. At high …


Slimsvm : A Simple Implementation Of Support Vector Machine For Analysis Of Microarray Data, Avik Karmaker Aug 2004

Slimsvm : A Simple Implementation Of Support Vector Machine For Analysis Of Microarray Data, Avik Karmaker

Theses

Support Vector Machine (SVM) is a supervised machine learning technique being widely used in multiple areas of biological analysis including microarray data analysis. SlimSVM has been developed with the intention of replacing OSU SVM as the classification component of GenoIterSVM in order to make it independent of other SVM packages. GenolterSVM, developed by Dr. Marc Ma, is a SVM implementation with an iterative refinement algorithm for improved accuracy of classification of genotype microarray data. SlimSVM is an object-oriented, modular, and easy-to-use implementation written in C++. It supports dot (linear) and polynomial (non-linear) kernels. The program has been tested with artificial …


The Use Of Bauxite Residue To Control Diffuse Phosphorus Pollution In Western Australia – A Win-Win-Win Outcome, Robert Summers, Mark Rivers, Martin Clarke Aug 2004

The Use Of Bauxite Residue To Control Diffuse Phosphorus Pollution In Western Australia – A Win-Win-Win Outcome, Robert Summers, Mark Rivers, Martin Clarke

Conference papers and presentations

The Department of Agriculture, Western Australia has been working with Alcoa World Alumina Australia Ltd for more than ten years investigating the potential to use bauxite refining residues as soil amendments for the poor, acidic, sandy soils of the Swan Coastal Plain in south west Australia. Regional waterways, especially the Peel Inlet and Harvey Estuary, have historically been susceptible to nuisance algal blooms fed by phosphorus in run-off from farmland and urban areas. Extensive laboratory, field and catchment-scale trials have shown the ability of soil amendment with fine bauxite refining residue (now trademarked in this context as Alkaloam™) to reduce …


An Audit Of The Uptake Of Agricultural Nutrient Management Practices In The Peel-Harvey Catchment, Kelly Lavell, Robert Summers, David Weaver, Martin Clarke, John Grant, Simon Neville Aug 2004

An Audit Of The Uptake Of Agricultural Nutrient Management Practices In The Peel-Harvey Catchment, Kelly Lavell, Robert Summers, David Weaver, Martin Clarke, John Grant, Simon Neville

Conference papers and presentations

Recent funding through the Coastal Catchments Initiative aims to significantly reduce the discharge of nutrients to the waterways of the eutrophic Peel-Harvey catchment. A range of projects within this initiative have been developed, which include activities designed to develop, test and implement point and non-point source best management practices (BMP) for the control of nutrient export, and to audit the current levels of adoption of these practices. Landholders who manage approximately 30% of the catchment area have been interviewed under major BMP themes of fertiliser management, soil amendment, perennial pastures, riparian and water management, revegetation, irrigation management and effluent management. …


Singular Value Decomposition Of Analogs Of Gbr 12909, Anna Fiorentino Aug 2004

Singular Value Decomposition Of Analogs Of Gbr 12909, Anna Fiorentino

Theses

Analogs of GBR 12909 are drugs that could potentially be used to treat cocaine addiction. Singular Value Decomposition (SVD) is a multivariate analysis technique used to show relationships between the data and the variables associated with the data. The input data consists of the conformers of each analog (DM324, 728 conformers; TP250, 739 conformers) along with the eight torsional angles (Al, A2, B1-B6). A novel scaling technique was developed to address the problem of data circularity by subtracting the values of the torsional angles of the global energy minimum conformation from those of each conformer.

In SVD the original data …


Space Time Spreading With Modified Walsh-Hadamard Sequences, Peter James Vial, Beata J. Wysocki, I. Raad, Tadeusz A. Wysocki Aug 2004

Space Time Spreading With Modified Walsh-Hadamard Sequences, Peter James Vial, Beata J. Wysocki, I. Raad, Tadeusz A. Wysocki

Faculty of Informatics - Papers (Archive)

Previous work has shown that the performance of a space time spreading (STS) system using Walsh codes with two transmit antennas at the base station (BS) is degraded in the presence of mutual interference from adjacent sectors in the same cell. We use modified Walsh-Hadamard sequences exhibiting improved cross-correlation performance, which potentially mitigates the effects of MAI (multiple access interference). The presented study also looks at variation of sets of different modified Walsh-Hadamard codes being used by the adjacent interferer, with a hundred randomly selected pairings being chosen, as well as the case where one set of alternate codes is …


Distributed, Collaborative Learning Environments Using Ad Hoc Networks, A. Fuller, Penelope Mcfarlane, D. F. Saffioti Aug 2004

Distributed, Collaborative Learning Environments Using Ad Hoc Networks, A. Fuller, Penelope Mcfarlane, D. F. Saffioti

Faculty of Informatics - Papers (Archive)

Computer assisted distributed or collaborative learning environments have been in existence for some time, however one impediment to more widespread use has been the need for a permanent wired network infrastructure. In this paper we discuss the development of a prototype tool that allows the formation of an ad hoc network at any time, and in any locale.


Living With Inconsistencies In A Multidatabase System, J. R. Getta Aug 2004

Living With Inconsistencies In A Multidatabase System, J. R. Getta

Faculty of Informatics - Papers (Archive)

Integration of autonomous sources of information is one of the most important problems in implementation of the global information systems. This paper considers multidatabase systems as one of the typical architectures of global information services and addresses a problem of storing and processing inconsistent information in such systems. A new data model proposed in the paper separates sure from inconsistent information and introduces a system of elementary operations on the containers with sure and inconsistent information. A review of the implementation aspects in an environment of a typical relational database management system concludes the paper.


Certalert Aug 2004

Certalert

Other Bird Strike and Aviation Materials

This Certalert clarifies the roles of, and relationship between the Federal Aviation Administration (FAA) and the United States Department of Agriculture/Animal and Plant Health Inspection Service/Wildlife Services (WS) with regards to wildlife hazards on or near airports.


Development Of Dose Conversion Coefficients For Radionuclides Produced In Spallation Neutron Sources: Quarterly Progress Report 5/1/04 – 8/31/04, Phillip W. Patton, Mark Rudin Aug 2004

Development Of Dose Conversion Coefficients For Radionuclides Produced In Spallation Neutron Sources: Quarterly Progress Report 5/1/04 – 8/31/04, Phillip W. Patton, Mark Rudin

Transmutation Sciences Physics (TRP)

The research consortium comprised of representatives from several universities and national laboratories has successfully generated internal and external dose conversion coefficients for twenty radionuclides produced in spallation neutron sources. These dose coefficients fill data gaps exist in Federal Guide Report No. 11 and in Publications 68 and 72 of the International Commission on Radiological Protection (ICRP). Currently, more nuclear data is needed for the rare radionuclides produced from a mercury target.


On The Dressing Method For The Generalised Zakharov-Shabat System, Rossen Ivanov Aug 2004

On The Dressing Method For The Generalised Zakharov-Shabat System, Rossen Ivanov

Articles

The dressing procedure for the Generalised Zakharov-Shabat system is well known for systems, related to sl(N) algebras. We extend the method, constructing explicitly the dressing factors for some systems, related to orthogonal and symplectic Lie algebras. We consider ’dressed’ fundamental analytical solutions with simple poles at the prescribed eigenvalue points and obtain the corresponding Lax potentials, representing the soliton solutions for some important nonlinear evolution equations.


Synergisms Of Electric Or Electromagnetic Fields And Photodynamic Effects Induce Apoptosis And Necrosis Of Cancer Cells, Radeva Maria, Lambrera Maya, Angelova Plamena, Traitcheva Nelly, Berg Hermann Aug 2004

Synergisms Of Electric Or Electromagnetic Fields And Photodynamic Effects Induce Apoptosis And Necrosis Of Cancer Cells, Radeva Maria, Lambrera Maya, Angelova Plamena, Traitcheva Nelly, Berg Hermann

Journal of Electrochemistry

Weak pulsating sinusoidal electromagnetic fields (PEMF) have been applied to change membrane permeation and induction of apoptosis (necrosis). In the case of suspension of human cancer cells U-937 and K-562 inside of Helmholtz-coils the amplitude of PEMF B=10 and at 39mT (at 50 Hz) was combined gradually with the cytotoxic agent actinomycin-C on one hand with its novel photodynamic activity on the other. Depending on temperature, pH-value and treatment time the necrosis of these cells was determined by means of trypan blue staining as well as the induced apoptosis by FACScan technique. Synergisms were discovered yielding high rates of cell …


Chemical Microetching Of Three-Dimensional Gear-Like Pattern On Nickel Surface, Zhu-Fang Liu Aug 2004

Chemical Microetching Of Three-Dimensional Gear-Like Pattern On Nickel Surface, Zhu-Fang Liu

Journal of Electrochemistry

The chemical micromachining on nickel surface with three-dimensional (3D) gear-like mold was realized by confined etchant layer technique (CELT). By using effective chemical etching and scavenging system (HNO_(3) + NaOH) and optimizing experimental parameters, such as the etching time, etching current density, concentration of the etchant or and scavenger, we obtained the etched pattern, which is close to negative copy of the mold. The etched micro-pattern characterized by SEM and AFM, demonstrates that CELT can be applied to the 3-D microstructure replication on nickel surface .


The Electrochemical Behavior And Determination Of Gsh At The Powder Microelectrode, Jian Chen, Zhong-Yu He, Chuansin Cha, Huan Liu Aug 2004

The Electrochemical Behavior And Determination Of Gsh At The Powder Microelectrode, Jian Chen, Zhong-Yu He, Chuansin Cha, Huan Liu

Journal of Electrochemistry

In this paper, the electrochemical behavior of GSH at the surface of platinum(Pt) electrode, glass carbon(GC) electrode and acetylene black packed powder microelectrode (AB-PME) was studied. It was found that the electrochemical oxidations of GSH at both Pt and GC electrode were highly irreversible. No current peak or current plateau could be observed from the CV curves. The direct electro-oxidation of GSH at carbon surface was achieved by using the PME technique.In this case, the apparent reversibility of GSH oxidation was enhanced significatly .The overpotential of GSH oxidation was reduced to 0.5 V at the surface of AB-PME compared with …


Nucleation And Crystal Growth Of Pt Electrodeposition On Poly Crystal Au Microdisc Electrode, Zhi-Yong Tao, Pei-Fang Liu Aug 2004

Nucleation And Crystal Growth Of Pt Electrodeposition On Poly Crystal Au Microdisc Electrode, Zhi-Yong Tao, Pei-Fang Liu

Journal of Electrochemistry

Based on the Fleischmann's model of nucleation and crystal growth for electrodeposition combined with the Barradas-Bosco's adsorption-nucleation model for electrochemical phase formation, the chronoamperometry was well fitted for Pt deposition on polycrystalline Au micro disc electrodes (30 μm in diameter) in different H_(2)PtCl_(6) concentrations at different over-potentials. The initial stage of Pt deposition in dilute H_(2)PtCl_(6) could be interpreted by the model of H_(2)PtCl_(6 ) adsorption combined with instantaneous nucleation and two-dimensional cylindrical growth. The rate constant of the two-dimensional growth increased linearly with overpotential. Then the deposit grew layer by layer and the rate constant increased non-linearly with overpotential. …