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Articles 301 - 330 of 3435
Full-Text Articles in Physical Sciences and Mathematics
A Theoretical Framework For The Multicast Address Allocation Problem, Daniel Zappala, Chris Gauthierdickey, Virginia Lo, Timothy Singer
A Theoretical Framework For The Multicast Address Allocation Problem, Daniel Zappala, Chris Gauthierdickey, Virginia Lo, Timothy Singer
Faculty Publications
The multicast address allocation problem requires Internet domains to allocate unique addresses to multicast applications from a globally-shared space. We develop a theoretical framework for multicast allocation algorithms that is influenced by subcube allocation in hypercube computer systems. Based on this framework we derive complexity results for the address allocation problem and describe several new allocation algorithms that use a hypercube model for address representation.
Discrete Singular Convolution And Its Application To The Analysis Of Plates With Internal Supports. Part 1: Theory And Algorithm, G. W. Wei, Yibao Zhao, Y. Xiang
Discrete Singular Convolution And Its Application To The Analysis Of Plates With Internal Supports. Part 1: Theory And Algorithm, G. W. Wei, Yibao Zhao, Y. Xiang
Research Collection Lee Kong Chian School Of Business
This paper presents a novel computational approach, the discrete singular convolution (DSC) algorithm, for analysing plate structures. The basic philosophy behind the DSC algorithm for the approximation of functions and their derivatives is studied. Approximations to the delta distribution are constructed as either bandlimited reproducing kernels or approximate reproducing kernels. Unified features of the DSC algorithm for solving differential equations are explored. It is demonstrated that different methods of implementation for the present algorithm, such as global, local, Galerkin, collocation, and finite difference, can be deduced from a single starting point. The use of the algorithm for the vibration analysis …
Soils Of Mississippi County, Arkansas, J. M. Mckimmey, B. Dixon, H. D. Scott, C. M. Scarlat
Soils Of Mississippi County, Arkansas, J. M. Mckimmey, B. Dixon, H. D. Scott, C. M. Scarlat
Research Reports and Research Bulletins
Along with air and water, soil contributes essential processes to the natural order of global cycles. With the exception of edibles from the sea, virtually everything we, and most other land-based animals, eat is derived from soil. Soil is a storage medium of essential minerals and nutrients for fulfilling our agricultural and nutritional needs. Humans work the soil to provide the basics of food, clothing, and shelter. We also use the soil as a medium to store and discard our waste. Virtually everything we do is in some way connected to soil
Simultaneous Trapping Of Rubidium And Metastable Argon In A Magneto-Optical Trap, C. I. Sukenik, H. C. Busch
Simultaneous Trapping Of Rubidium And Metastable Argon In A Magneto-Optical Trap, C. I. Sukenik, H. C. Busch
Physics Faculty Publications
We have simultaneously confined rubidium and metastable argon in a dual-species magneto-optical trap (MOT). Here a binary mixture of atomic species from different groups of the periodic table have been optically confined at ultracold temperatures. We describe the apparatus and characterize the individual, single species MOTs and the dual-species MOT. Both fluorescence and ion production are monitored. With both species trapped, we observe ~5106 85Rb atoms and ~2106 40Ar* atoms. Realization of the dual-species trap opens the way for detailed studies of Penning and associative ionization, photoassociative spectroscopy, and eventually for the production of bound, ultracold RbAr molecules.
Removal Versus Ablation In Krf Dry Laser Cleaning Of Polystyrene Particles From Silicon, Sergey I. Kudryashov, Susan D. Allen
Removal Versus Ablation In Krf Dry Laser Cleaning Of Polystyrene Particles From Silicon, Sergey I. Kudryashov, Susan D. Allen
Mechanical Engineering - Daytona Beach
Direct absorption and melting of 0.2, 0.5 and 1.1 μm polystyrene particles on a Si substrate irradiated by 248 nm excimer laser radiation was found to contribute to their dry laser removal via a "hopping" mechanism at cleaning thresholds of 0.05, 0.1, and 0.16 J/cm 2, respectively. Ablation of these particles, which starts near the beginning of substrate deceleration at fluences above 0.4-0.5 J/cm 2, suppresses particle removal due to ablative recoil momentum. At fluences above a second cleaning threshold of 0.7 J/cm 2 particles are completely evaporated without any visible surface damage of the Si substrate.
© …
Mining Of Correlated Rules In Genome Sequences, L. Lin, L. Wong, Tze-Yun Leong, P. S. Lai
Mining Of Correlated Rules In Genome Sequences, L. Lin, L. Wong, Tze-Yun Leong, P. S. Lai
Research Collection School Of Computing and Information Systems
With the huge amount of data collected by scientists in the molecular genetics community in recent years, there exists a need to develop some novel algorithms based on existing data mining techniques to discover useful information from genome databases. We propose an algorithm that integrates the statistical method, association rule mining, and classification rule mining in the discovery of allelic combinations of genes that are peculiar to certain phenotypes of diseased patients.
Motion-Based Video Representation For Scene Change Detection, Chong-Wah Ngo, Ting-Chuen Pong, Hong-Jiang Zhang
Motion-Based Video Representation For Scene Change Detection, Chong-Wah Ngo, Ting-Chuen Pong, Hong-Jiang Zhang
Research Collection School Of Computing and Information Systems
In this paper, we present a new framework to automatically group similar shots into one scene, where a scene is generally referred to as a group of shots taken place in the same site. Two major components in this framework are based on the motion characterization and background segmentation. The former component leads to an effective video representation scheme by adaptively selecting and forming keyframes. The later is considered novel in that background reconstruction is incorporated into the detection of scene change. These two components, combined with the color histogram intersection, establish our basic concept on assessing the similarity of …
A Pseudo Nearest-Neighbor Approach For Missing Data Recovery On Gaussian Random Data Sets, Xiaolu Huang, Qiuming Zhu
A Pseudo Nearest-Neighbor Approach For Missing Data Recovery On Gaussian Random Data Sets, Xiaolu Huang, Qiuming Zhu
Computer Science Faculty Publications
Missing data handling is an important preparation step for most data discrimination or mining tasks. Inappropriate treatment of missing data may cause large errors or false results. In this paper, we study the effect of a missing data recovery method, namely the pseudo- nearest neighbor substitution approach, on Gaussian distributed data sets that represent typical cases in data discrimination and data mining applications. The error rate of the proposed recovery method is evaluated by comparing the clustering results of the recovered data sets to the clustering results obtained on the originally complete data sets. The results are also compared with …
Rydberg-Atom Population Transfer By Population Trapping In A Chirped Microwave Pulse, J. Lambert, Michael Noel, T. F. Gallagher
Rydberg-Atom Population Transfer By Population Trapping In A Chirped Microwave Pulse, J. Lambert, Michael Noel, T. F. Gallagher
Physics Faculty Research and Scholarship
We demonstrate that Rydberg atoms can be transferred to states of lower principal quantum number by exposing them to a frequency chirped microwave pulse. Specifically, we have transferred n=75 atoms to n=66 with a 400-ns pulse chirped from 7.8 to 11.8 GHz. In spite of the large number of coupled levels, using a simplified model we can describe the process reasonably well as a sequence of adiabatic rapid passages.
Defending Against Redirect Attacks In Mobile Ip, Robert H. Deng, Jianying Zhou, Feng Bao
Defending Against Redirect Attacks In Mobile Ip, Robert H. Deng, Jianying Zhou, Feng Bao
Research Collection School Of Computing and Information Systems
The route optimization operation in Mobile IP Version 6 (MIPv6) allows direct routing from any correspondent node to any mobile node and thus eliminates the problem of "triangle routing" present in the base Mobile IP Version 4 (MIPv4) protocol. Route optimization, however, requires that a mobile node constantly inform its correspondent nodes about its new care-of addresses by sending them binding update messages. Unauthenticated or malicious binding updates open the door for intruders to perform redirect attacks, i.e., malicious acts which redirect traffic from correspondent nodes to locations chosen by intruders. How to protect binding update messages to defend against …
Knowledge Discovery From Texts: A Concept Frame Graph Approach, Kanagasabai Rajaraman, Ah-Hwee Tan
Knowledge Discovery From Texts: A Concept Frame Graph Approach, Kanagasabai Rajaraman, Ah-Hwee Tan
Research Collection School Of Computing and Information Systems
We address the text content mining problem through a concept based framework by constructing a conceptual knowledge base and discovering knowledge therefrom. Defining a novel representation called the Concept Frame Graph (CFG), we propose a learning algorithm for constructing a CFG knowledge base from text documents. An interactive concept map visualization technique is presented for user-guided knowledge discovery from the knowledge base. Through experimental studies on real life documents, we observe that the proposed approach is promising for mining deeper knowledge.
Predicting Bottleneck Bandwidth Sharing By Generalized Tcp Flows, Archan Misra, Teunis Ott, John Baras
Predicting Bottleneck Bandwidth Sharing By Generalized Tcp Flows, Archan Misra, Teunis Ott, John Baras
Research Collection School Of Computing and Information Systems
The paper presents a technique for computing the individual throughputs and the average queue occupancy when multiple TCP connections share a single bottleneck buffer. The bottleneck buffer is assumed to perform congestion feedback via randomized packet marking or drops. We first present a fixed point-based analytical technique to compute the mean congestion window sizes, the mean queue occupancy and the individual throughputs when the TCP flows perform idealized congestion avoidance. We subsequently extend the technique to analyze the case where TCP flows perform generalized congestion avoidance and demonstrate the use of this technique under the Assured Service model, where each …
City Of Norfolk - Shoreline Situation Report, Marcia Berman, Harry Berquist, Carl Hershner, Sharon Killeen, Tamia Rudnicky, Daniel E. Schatt, David Weiss, Helen Woods
City Of Norfolk - Shoreline Situation Report, Marcia Berman, Harry Berquist, Carl Hershner, Sharon Killeen, Tamia Rudnicky, Daniel E. Schatt, David Weiss, Helen Woods
Reports
No abstract provided.
A Visual Tool For Building Logical Data Models Of Websites, Zehua Liu, Wee-Keong Ng, Feifei Li, Ee Peng Lim
A Visual Tool For Building Logical Data Models Of Websites, Zehua Liu, Wee-Keong Ng, Feifei Li, Ee Peng Lim
Research Collection School Of Computing and Information Systems
Information sources over the WWW contain a large amount of data organized according to different interests and values. Thus, it is important that facilities are there to enable users to extract information of interest in a simple and effective manner. To do this, We propose the Wiccap Data Model, an XML data model that maps Web information sources into commonly perceived logical models, so that information can be extracted automatically according to users' interests. To accelerate the creation of data models, we have implemented a visual tool, called the Mapping Wizard, to facilitate and automate the process of producing Wiccap …
Web Classification Using Support Vector Machine, Aixin Sun, Ee Peng Lim
Web Classification Using Support Vector Machine, Aixin Sun, Ee Peng Lim
Research Collection School Of Computing and Information Systems
In web classification, web pages from one or more web sites are assigned to pre-defined categories according to their content. Since web pages are more than just plain text documents, web classification methods have to consider using other context features of web pages, such as hyperlinks and HTML tags. In this paper, we propose the use of Support Vector Machine (SVM) classifiers to classify web pages using both their text and context feature sets. We have experimented our web classification method on the WebKB data set. Compared with earlier Foil-Pilfs method on the same data set, our method has been …
An Analysis Of Shoreline Development Risk For Secondary Dune Systems In Tidewater Virginia With Associated Management Recommendations, Lyle M. Varnell, C. Scott Hardaway Jr.
An Analysis Of Shoreline Development Risk For Secondary Dune Systems In Tidewater Virginia With Associated Management Recommendations, Lyle M. Varnell, C. Scott Hardaway Jr.
Reports
This project was done in response to concerns by environmental resource managers of historic and potential adverse impacts to Virginia’s secondary dune ecosystems. Virginia environmental regulatory programs have little decision-making authority over the use of secondary dunes as these areas are not included in the Coastal Primary Sand Dune Act (the Dunes Act). These areas function as estuarine edge habitat and provide natural upland erosion control, and are thus valuable to estuarine and coastal plain fauna and adjacent upland property owners.
Tmdls: Statistical Correlations Or Mechanistic Modeling?, Scott A. Wells, Thomas M. Cole
Tmdls: Statistical Correlations Or Mechanistic Modeling?, Scott A. Wells, Thomas M. Cole
Civil and Environmental Engineering Faculty Publications and Presentations
In developing TMDL waste-load allocations for the Snake River-Reservoir system in Western Idaho and Eastern Oregon, determinations of the assimilative capacity of the system and the impact of pollutant reduction strategies has been performed using both a statistical-correlation approach and a mechanistic modeling approach. The system included the Lower Snake River, Brownlee Reservoir, Oxbow Reservoir, and Hells Canyon Reservoir with the focus was on Brownlee Reservoir.
The statistical approach used on Brownlee Reservoir divided the system into riverine and lacustrine zones. Field data were then averaged over season and location to provide statistical correlations, such as between total phosphorus (TP) …
Modification Of An Injection Molding Machine To Mold Micro Parts With A Liga Mold, Emil John Geiger
Modification Of An Injection Molding Machine To Mold Micro Parts With A Liga Mold, Emil John Geiger
Honors Theses
No abstract provided.
Developing A Sensing System For The Measurement Of Oxygen Concentration In Liquid Pb-Bi Eutectic: Quarterly Progress Report (Aug. 01 – Oct. 31, 2002), Yingtao Jiang, Bingmei Fu, Woosoon Yim
Developing A Sensing System For The Measurement Of Oxygen Concentration In Liquid Pb-Bi Eutectic: Quarterly Progress Report (Aug. 01 – Oct. 31, 2002), Yingtao Jiang, Bingmei Fu, Woosoon Yim
Transmutation Sciences Materials (TRP)
After two month intensive work in LANL, some preliminary sensor calibration curves have been obtained. Further data analysis shall be performed to assess the theoretical and measured data. Also, a new experimental apparatus shall be designed and located in UNLV to continue the left work.
Technical Progress:
• A set of calibration curves of voltage vs. temperature ranging from 3000C to 5000C under various oxygen concentrations in liquid LBE for the YSZ oxygen sensor has been obtained and has been reported in one paper.
• A meeting with LBE committee and other faculty members in AAA …
Effects Of Light Scalar Mesons In Η\To 3Π Decay, Joseph Schechter, Abdou Abdel-Rehim, Deirdre Black, Amir H. Fariborz
Effects Of Light Scalar Mesons In Η\To 3Π Decay, Joseph Schechter, Abdou Abdel-Rehim, Deirdre Black, Amir H. Fariborz
Physics - All Scholarship
We study the role of a possible nonet of light scalar mesons in the still interesting \eta \to 3\pi decay process, with the primary motivation of learning more about the scalars themselves. The framework is a conventional non-linear chiral Lagrangian of pseudoscalars and vectors, extended to include the scalars. The parameters involving the scalars were previously obtained to fit the s-wave \pi\pi and \piK scatterings in the region up to about 1 GeV as well as the strong decay \eta' \to \eta \pi\pi. At first, one might expect a large enhancement from diagrams including a light \sigma(560). However there is …
Locally Efficient Estimation With Bivariate Right Censored Data , Christopher M. Quale, Mark J. Van Der Laan, James M. Robins
Locally Efficient Estimation With Bivariate Right Censored Data , Christopher M. Quale, Mark J. Van Der Laan, James M. Robins
U.C. Berkeley Division of Biostatistics Working Paper Series
Estimation for bivariate right censored data is a problem that has had much study over the past 15 years. In this paper we propose a new class of estimators for the bivariate survivor function based on locally efficient estimation. The locally efficient estimator takes bivariate estimators Fn and Gn of the distributions of the time variables T1,T2 and the censoring variables C1,C2, respectively, and maps them to the resulting estimator. If Fn and Gn are consistent estimators of F and G, respectively, then the resulting estimator will be nonparametrically efficient (thus the term ``locally efficient''). However, if either Fn or …
Environmental Regulation In The Presence Of Environmentally Conscious Consumers., Sangeeta Bansal Dr.
Environmental Regulation In The Presence Of Environmentally Conscious Consumers., Sangeeta Bansal Dr.
Doctoral Theses
The Problem and Literature Review There is a growing concern for the environmental degradation caused by various economic activities. Clean environment, once regarded as a free good, has now become a scarce resource due to cumulative accumulation of pollution over the years. Being a public good, it may not be possible to assign clear property rights to environment. Hence, even though it has become a scarce resource, economic agents continue to regard it as a free good and tend to ignore the harmful effects of their activities on the environment. This causes a distortion between the market and socially optimal …
Asymptotic Solitons For A Higher-Order Modified Korteweg–De Vries Equation, Timothy R. Marchant
Asymptotic Solitons For A Higher-Order Modified Korteweg–De Vries Equation, Timothy R. Marchant
Faculty of Informatics - Papers (Archive)
Solitary wave interaction for a higher-order modified Korteweg–de Vries (mKdV) equation is examined. The higher-order mKdV equation can be asymptotically transformed to the mKdV equation, if the higher-order coefficients satisfy a certain algebraic relationship. The transformation is used to derive the higher-order two-soliton solution and it is shown that the interaction is asymptotically elastic. Moreover, the higher-order phase shifts are derived using the asymptotic theory. Numerical simulations of the interaction of two higher-order solitary waves are also performed. Two examples are considered, one satisfies the algebraic relationship derived from the asymptotic theory, and the other does not. For the example …
Femtosecond Pump-Probe Reflectivity Study Of Silicon Carrier Dynamics, A. J. Sabbah, D. Mark Riffe
Femtosecond Pump-Probe Reflectivity Study Of Silicon Carrier Dynamics, A. J. Sabbah, D. Mark Riffe
All Physics Faculty Publications
We have studied the ultrafast optical response of native-oxide terminated Si(001) with pump-probe reflectivity using 800 nm, 28 fs pulses at an excitation density of (5.5±0.3)×1018cm-3. Time-dependent reflectivity changes comprise third-order-response coherent-transient variations arising from anisotropic state filling and linear-response variations arising from excited free carriers, state filling, and lattice heating. A time constant of 32±5fs associated with momentum relaxation is extracted from the coherent-transient variations. The state-filling and free-carrier responses are sensitive to carrier temperature, allowing an electron-phonon energy relaxation time of 260±30fs to be measured. The recovery of the reflectivity signal back towards its …
Asymptotic Solitons For A Higher-Order Modified Korteweg–De Vries Equation, T. Marchant
Asymptotic Solitons For A Higher-Order Modified Korteweg–De Vries Equation, T. Marchant
Tim Marchant
Solitary wave interaction for a higher-order modified Korteweg–de Vries (mKdV) equation is examined. The higher-order mKdV equation can be asymptotically transformed to the mKdV equation, if the higher-order coefficients satisfy a certain algebraic relationship. The transformation is used to derive the higher-order two-soliton solution and it is shown that the interaction is asymptotically elastic. Moreover, the higher-order phase shifts are derived using the asymptotic theory. Numerical simulations of the interaction of two higher-order solitary waves are also performed. Two examples are considered, one satisfies the algebraic relationship derived from the asymptotic theory, and the other does not. For the example …
Distributions Of Nobel Metal Pd And Pt In Mesoporous Silica, J. Arbiol, A. Cabot, J. R. Morante, Fanglin Chen, Meilin Liu
Distributions Of Nobel Metal Pd And Pt In Mesoporous Silica, J. Arbiol, A. Cabot, J. R. Morante, Fanglin Chen, Meilin Liu
Faculty Publications
Mesoporous silicananostructures have been synthesized and loaded with Pd and Pt catalytic noble metals. It is found that Pd forms small nanoclusters (3–5 nm) on the surface of the mesoporous structure whereas Pt impregnation results in the inclusion of Pt nanostructures within the silica hexagonal pores (from nanoclusters to nanowires). It is observed that these materials have high catalyticproperties for CO–CH4CO–CH4CO–CH4 combustion, even in a thick film form. In particular, results indicate that the Pt and Pd dispersed in mesoporous silica are catalytically active as a selective filter for gas sensors.
An Observation Of A Fast External Atmospheric Acoustic-Gravity Wave, J. H. Hecht, R. L. Walterscheid, Michael P. Hickey Ph.D., R. J. Rudy, A. Z. Liu
An Observation Of A Fast External Atmospheric Acoustic-Gravity Wave, J. H. Hecht, R. L. Walterscheid, Michael P. Hickey Ph.D., R. J. Rudy, A. Z. Liu
Publications
In November 1999 a new near-IR airglow imaging system was deployed at the Starfire Optical Range outside of Albuquerque, New Mexico. This system allowed wide angle images of the airglow to be collected, with high signal to noise, every 3 seconds with a one second integration time. At approximately 1000 UT on November 17, 1999, a fast wavelike disturbance was seen propagating through the OH Meinel airglow layer. This wave had an observed period of ≈215 seconds, an observed phase velocity of ≈160 m/s and a horizontal wavelength of ≈35 km. This phase velocity is among the fastest yet reported …
Horizon Occlusion Culling For Real-Time Rendering Of Hierarchical Terrains, Parris K. Egbert, Brandon Lloyd
Horizon Occlusion Culling For Real-Time Rendering Of Hierarchical Terrains, Parris K. Egbert, Brandon Lloyd
Faculty Publications
We present a technique to perform occlusion culling for hierarchical terrains at run-time. The algorithm is simple to implement and requires minimal pre-processing and additional storage, yet leads to 2-4 times improvement in framerate for views with high degrees of occlusion. Our method is based on the well-known occlusion horizon algorithm. We show how to adapt the algorithm for use with hierarchical terrains. The occlusion horizon is constructed as the terrain is traversed in an approximate front to back ordering. Regions of the terrain are compared to the horizon to determine when they are completely occluded from the viewpoint. Culling …
Managing Nature In Today's World, Walter E. Howard
Managing Nature In Today's World, Walter E. Howard
2002 Bird Strike Committee-USA/Canada, 4th Annual Meeting, Sacramento, CA
The objective of my talk is to help airport authorities better understand the turmoil they encounter when managing birds and other wildlife populations. Many are reluctant to manage birds and mammals because they know that it will inevitably stir up controversy. Especially this is true when the program includes lethal means. Many people think all problems can be resolved by using non-lethal frightening devices or by live-trapping offending animals and relocating them away from airports. There are some sound arguments as to why it is biologically, ecologically and ethically proper to even use lethal means to resolve some airport wildlife …
Mandatory Strike Reporting: The Time Has Come, Paul Eschenfelder
Mandatory Strike Reporting: The Time Has Come, Paul Eschenfelder
2002 Bird Strike Committee-USA/Canada, 4th Annual Meeting, Sacramento, CA
The reporting of wildlife collisions with aircraft in almost all places, worldwide, is voluntary. As a result data with which to design, manufacture and operate aircraft to mitigate this hazard is poor. Voluntary reporting of strikes has resulted in data collection rates in the USA of around 20%, and only about 9% of the reported strikes contain complete data on bird species. Aviation manufacturers also agree that collection of strike data is difficult, incomplete and without an industry best practice. Air carriers, when research is done, are amazed to find that strike rates may be eight times higher than their …