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2010

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Articles 1441 - 1470 of 8620

Full-Text Articles in Physical Sciences and Mathematics

Facile Pyrolytic Synthesis Of Silicon Nanowires, Joo C. Chan, Hoang Tran, James W. Pattison, Shankar B. Rananavare Oct 2010

Facile Pyrolytic Synthesis Of Silicon Nanowires, Joo C. Chan, Hoang Tran, James W. Pattison, Shankar B. Rananavare

Chemistry Faculty Publications and Presentations

One-dimensional nanostructures such as silicon nanowires (SiNW) are attractive candidates for low power density electronic and optoelectronic devices including sensors. A new simple method for SiNW bulk synthesis[1, 2] is demonstrated in this work, which is inexpensive and uses low toxicity materials, thereby offering a safe, energy efficient and green approach. The method uses low flammability liquid phenylsilanes, offering a safer avenue for SiNW growth compared with using silane gas. A novel, duo-chamber glass vessel is used to create a low-pressure environment where SiNWs are grown through vapor-liquid-solid mechanism using gold nanoparticles as a catalyst. The catalyst decomposes silicon precursor …

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Extensive Aerosol Optical Properties And Aerosol Mass Related Measurements During Tramp/Texaqs 2006 – Implications For Pm Compliance And Planning, Monica Elizabeth Wright, Dean B. Atkinson, Luke Ziemba, Robert Griffin, Naruki Hiranuma, Sarah D. Brooks, James Flynn, Ryan Perna, Bernhard Rappenglück, Winston Luke, Paul Kelley Oct 2010

Extensive Aerosol Optical Properties And Aerosol Mass Related Measurements During Tramp/Texaqs 2006 – Implications For Pm Compliance And Planning, Monica Elizabeth Wright, Dean B. Atkinson, Luke Ziemba, Robert Griffin, Naruki Hiranuma, Sarah D. Brooks, James Flynn, Ryan Perna, Bernhard Rappenglück, Winston Luke, Paul Kelley

Chemistry Faculty Publications and Presentations

Extensive aerosol optical properties, particle size distributions, and Aerodyne quadrupole aerosol mass spectrometer measurements collected during TRAMP/TexAQS 2006 were examined in light of collocated meteorological and chemical measurements. Much of the evident variability in the observed aerosol-related air quality is due to changing synoptic meteorological situations that direct emissions from various sources to the TRAMP site near the center of the Houston-Galveston-Brazoria (HGB) metropolitan area. In this study, five distinct long-term periods have been identified. During each of these periods, observed aerosol properties have implications that are of interest to environmental quality management agencies. During three of the periods, long …

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Structure Of The Cholera Toxin Secretion Channel In Its Closed State, Steve Reichow, Konstantin V. Korotkov, Wim Gj Hol, Tamir Gonen Oct 2010

Structure Of The Cholera Toxin Secretion Channel In Its Closed State, Steve Reichow, Konstantin V. Korotkov, Wim Gj Hol, Tamir Gonen

Chemistry Faculty Publications and Presentations

The type II secretion system (T2SS) is a macromolecular complex spanning the inner and outer membranes of Gram-negative bacteria. Remarkably, the T2SS secretes folded proteins including multimeric assemblies like cholera toxin and heat-labile enterotoxin from Vibrio cholerae and enterotoxigenic Escherichia coli, respectively. The major outer membrane T2SS protein is the “secretin” GspD. Electron cryomicroscopy reconstruction of the V. cholerae secretin at 19 Å resolution reveals a dodecameric structure reminiscent of a barrel with a large channel at its center that appears to contain a closed periplasmic gate. The GspD periplasmic domain forms a vestibule with a conserved constriction, and binds …

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Cooperative Interaction Of Transcription Termination Factors With The Rna Polymerase Ii C-Terminal Domain, Bradley M. Lunde, Steve Reichow, Minkyu Kim, Hyunsuk Suh, Thomas C. Leeper, Fan Yang, Hannes Mutschler, Stephen Buratowski, Anton Meinhart, Gabriele Varani Oct 2010

Cooperative Interaction Of Transcription Termination Factors With The Rna Polymerase Ii C-Terminal Domain, Bradley M. Lunde, Steve Reichow, Minkyu Kim, Hyunsuk Suh, Thomas C. Leeper, Fan Yang, Hannes Mutschler, Stephen Buratowski, Anton Meinhart, Gabriele Varani

Chemistry Faculty Publications and Presentations

Phosphorylation of the C-terminal domain of RNA polymerase II controls the co-transcriptional assembly of RNA processing and transcription factors. Recruitment relies on conserved CTDinteracting domains that recognize different CTD phosphoisoforms during the transcription cycle, but the molecular basis for their specificity remains unclear. We show that the CTD-interacting domains of two transcription termination factors, Rtt103 and Pcf11, achieve high affinity and specificity both by specifically recognizing the phosphorylated CTD and by cooperatively binding to neighboring CTD repeats. Single amino acid mutations at the protein-protein interface abolish cooperativity and affect recruitment at the 3′-end processing site in vivo. We suggest that …

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Youth Olympic Village Co-Space, Zin-Yan Chua, Yilin Kang, Xing Jiang, Kah-Hoe Pang, Andrew C. Gregory, Chi-Yun Tan, Wai-Lun Wong, Ah-Hwee Tan, Yew-Soon Ong, Chunyan Miao Oct 2010

Youth Olympic Village Co-Space, Zin-Yan Chua, Yilin Kang, Xing Jiang, Kah-Hoe Pang, Andrew C. Gregory, Chi-Yun Tan, Wai-Lun Wong, Ah-Hwee Tan, Yew-Soon Ong, Chunyan Miao

Research Collection School Of Computing and Information Systems

We have designed and implemented a 3D virtual world based on the Co-Space concept encompasses the Youth Olympic Village (YOV) and several sports competition venues. It is a massively multiplayer online (MMO) virtual world built according to the actual, physical locations of the YOV and sports competition venues. On top of that, the Co-Space is being populated with human-like avatars, which are created according to the actual human size and appearance; they perform their activities and interact with the users in realworld context. In addition, autonomous intelligent agents are integrated into the Co-Space to provide context-aware and personalized services to …

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Wsm'10: Second Acm Workshop On Social Media, Susanne Boll, Steven C. H. Hoi, Roelof Van Zwol, Jiebo Luo Oct 2010

Wsm'10: Second Acm Workshop On Social Media, Susanne Boll, Steven C. H. Hoi, Roelof Van Zwol, Jiebo Luo

Research Collection School Of Computing and Information Systems

The ACM SIGMM International Workshop on Social Media (WSM'10) is the second workshop held in conjunction with the ACM International Multimedia Conference (MM'10) at Firenze, Italy, 2010. This workshop provides a forum for researchers and practitioners from all over the world to share information on their latest investigations on social media analysis, exploration, search, mining, and emerging new social media applications.

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Wireless Sensing Without Sensors: An Experimental Study Of Motion/Intrusion Detection Using Rf Irregularity, Wei Qi Lee, Winston K. G. Seah, Hwee-Pink Tan, Zexi Yao Oct 2010

Wireless Sensing Without Sensors: An Experimental Study Of Motion/Intrusion Detection Using Rf Irregularity, Wei Qi Lee, Winston K. G. Seah, Hwee-Pink Tan, Zexi Yao

Research Collection School Of Computing and Information Systems

Motion and intrusion detection are often cited as wireless sensor network (WSN) applications with typical configurations comprising clusters of wireless nodes equipped with motion sensors to detect human motion. Currently, WSN performance is subjected to several constraints, namely radio irregularity and finite on-board computation/energy resources. Radio irregularity in radio frequency (RF) propagation rises to a higher level in the presence of human activity due to the absorption effect of the human body. In this paper, we investigate the feasibility of monitoring RF transmission for the purpose of intrusion detection through experimentation. With empirical data obtained from the Crossbow TelosB platform …

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Detection Of Quercetin Using Polymer Coated Quartz Crystal Microbalance And The Modification Of Á-Zirconium Phosphate To Develop A Sorbent For Organic Pollutant Removal, Darlington Mlambo Oct 2010

Detection Of Quercetin Using Polymer Coated Quartz Crystal Microbalance And The Modification Of Á-Zirconium Phosphate To Develop A Sorbent For Organic Pollutant Removal, Darlington Mlambo

Dissertations (1934 -)

Sorption processes involve physical and chemical interactions of sorbents with analytes. These may involve the physical and/or chemical processes in which a substance is accumulated at an interface between two phases, or the intermixing of a substance with the matrix of a second phase. The two processes are referred to as adsorption and absorption respectively. The sorption capacities of different classes of sorbents have many potential and demonstrated applications such as sensor development, water treatment, environmental remediation and chromatographic separations. The goal of this work is to explore the sorption capacity of polymers as well as nanodimensional layered materials for …

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Online Multiple Kernel Learning: Algorithms And Mistake Bounds, Rong Jin, Steven C. H. Hoi, Tianbao Yang Oct 2010

Online Multiple Kernel Learning: Algorithms And Mistake Bounds, Rong Jin, Steven C. H. Hoi, Tianbao Yang

Research Collection School Of Computing and Information Systems

Online learning and kernel learning are two active research topics in machine learning. Although each of them has been studied extensively, there is a limited effort in addressing the intersecting research. In this paper, we introduce a new research problem, termed Online Multiple Kernel Learning (OMKL), that aims to learn a kernel based prediction function from a pool of predefined kernels in an online learning fashion. OMKL is generally more challenging than typical online learning because both the kernel classifiers and their linear combination weights must be learned simultaneously. In this work, we consider two setups for OMKL, i.e. combining …

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Context Modeling For Ranking And Tagging Bursty Features In Text Streams, Xin Zhao, Jing Jiang, Jing He, Xiaoming Li, Hongfei Yan, Dongdong Shan Oct 2010

Context Modeling For Ranking And Tagging Bursty Features In Text Streams, Xin Zhao, Jing Jiang, Jing He, Xiaoming Li, Hongfei Yan, Dongdong Shan

Research Collection School Of Computing and Information Systems

Bursty features in text streams are very useful in many text mining applications. Most existing studies detect bursty features based purely on term frequency changes without taking into account the semantic contexts of terms, and as a result the detected bursty features may not always be interesting or easy to interpret. In this paper we propose to model the contexts of bursty features using a language modeling approach. We then propose a novel topic diversity-based metric using the context models to find newsworthy bursty features. We also propose to use the context models to automatically assign meaningful tags to bursty …

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Application Of The Fractional Diffusion Equation For Predicting Market Behaviour, Jonathan Blackledge Oct 2010

Application Of The Fractional Diffusion Equation For Predicting Market Behaviour, Jonathan Blackledge

Articles

Most Financial modelling system rely on an underlying hypothesis known as the Eficient Market Hypothesi (EMH) including the famous BlackScholes formula for placing an option. However, the EMH has a fundamental flaw: it is based on the assumption that economic processes are normally distributed and it has long been known that this is not the case. This fundamental assumption leads to a number of shortcomings associated with using the EMH to analyse financial data which includes failure to predict the future volatility of a market share value. This paper introduces a new financial risk assessment model based on Levy statistics …

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Comparative Analysis Of Combinations Of Dimension Reduction And Data Mining Techniques For Malware Detection, Proceso L. Fernandez Jr, Jeffrey C. Yiu, Paul Albert R. Arana Oct 2010

Comparative Analysis Of Combinations Of Dimension Reduction And Data Mining Techniques For Malware Detection, Proceso L. Fernandez Jr, Jeffrey C. Yiu, Paul Albert R. Arana

Department of Information Systems & Computer Science Faculty Publications

Many malware detectors utilize data mining techniques as primary tools for pattern recognition. As the number of new and evolving malware continues to rise, there is an increasing need for faster and more accurate detectors. However, for a given malware detector, detection speed and accuracy are usually inversely related. This study explores several configurations of classification combined with feature selection. An optimization function involving accuracy and processing time is used to evaluate each configuration. A real data set provided by Trend Micro Philippines is used for the study. Among 18 di↵erent configurations studied, it is shown that J4.8 without feature …

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Evaluation Of Computational Techniques For Solving The Boltzmann Transport Equation For Lattice Thermal Conductivity Calculations, Aleksandr V. Chernatynskiy, Simon R. Phillpot Oct 2010

Evaluation Of Computational Techniques For Solving The Boltzmann Transport Equation For Lattice Thermal Conductivity Calculations, Aleksandr V. Chernatynskiy, Simon R. Phillpot

Physics Faculty Research & Creative Works

Three methods for computing thermal conductivity from lattice dynamics (the iterative method, the variational method, and the relaxation-time approximation) are compared for the prototypical case of solid argon. The iterative method is found to produce results in close agreement with Green-Kubo molecular-dynamics simulations, a formally correct method for computing thermal conductivity. The variational method and relaxation-time approximation are found to underestimate the thermal conductivity. The relationship among the methods is established; a combination of the iterative and variational methods is found to have a fastest convergence. Formal convergence of the iterative method is demonstrated and a simple mixing rule is …

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Geogram 2010, David J. Keeling Editor, Wku Department Of Geography And Geology Oct 2010

Geogram 2010, David J. Keeling Editor, Wku Department Of Geography And Geology

Earth, Environmental, and Atmospheric Sciences Publications

No abstract provided.

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Experimental Estimation Of The Gpr Groundwave Sampling Depth, Katherine R. Grote, Taylor Crist, Crystal Nickel Oct 2010

Experimental Estimation Of The Gpr Groundwave Sampling Depth, Katherine R. Grote, Taylor Crist, Crystal Nickel

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

Monitoring near-surface soil water content is essential for efficient water management and for understanding hydrologic processes in soils. Ground-penetrating radar (GPR) groundwaves are an approach that can be used to monitor the near-surface soil water content, but the efficacy of this technique is currently limited by the uncertainty surrounding the groundwave sampling depth. This research experimentally determines the sampling depth of GPR groundwaves under dry and saturated conditions in a sandy soil. Data were acquired using 250, 500, and 1000 MHz antennas within an experimental tank containing soil layers of contrasting electromagnetic velocities. Results show that the groundwave sampling depth …

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New Tests Of General Relativity, Quentin Bailey Oct 2010

New Tests Of General Relativity, Quentin Bailey

Publications

The last decade has seen a rapid increase in the number of precision tests of relativity. This research has been motivated by the intriguing possibility that tiny deviations from relativity might arise in the underlying theory that is widely believed to successfully mesh General Relativity (GR) with quantum physics. Many of these tests have been analyzed within an effective field theory framework which generically describes possible deviations from exact relativity and contains some traditional test frameworks as limiting cases. One part of the activity has been a resurgence of interest in tests of relativity in the Minkowski-spacetime context, where Lorentz …

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A Class Of Discontinuous Petrov–Galerkin Methods. Part Iv: The Optimal Test Norm And Time-Harmonic Wave Propagation In 1d., Jeffrey Zitelli, Leszek Demkowicz, Jay Gopalakrishnan, D. Pardo, V. M. Calo Oct 2010

A Class Of Discontinuous Petrov–Galerkin Methods. Part Iv: The Optimal Test Norm And Time-Harmonic Wave Propagation In 1d., Jeffrey Zitelli, Leszek Demkowicz, Jay Gopalakrishnan, D. Pardo, V. M. Calo

Mathematics and Statistics Faculty Publications and Presentations

The phase error, or the pollution effect in the finite element solution of wave propagation problems, is a well known phenomenon that must be confronted when solving problems in the high-frequency range. This paper presents a new method with no phase errors for one-dimensional (1D) time-harmonic wave propagation problems using new ideas that hold promise for the multidimensional case. The method is constructed within the framework of the discontinuous Petrov–Galerkin (DPG) method with optimal test functions. We have previously shown that such methods select solutions that are the best possible approximations in an energy norm dual to any selected test …

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Nmr-Based And Automated Docking Characterization Of Protein Structure, Dynamics, And Ligand Binding, Andrew Lawrence Olson Oct 2010

Nmr-Based And Automated Docking Characterization Of Protein Structure, Dynamics, And Ligand Binding, Andrew Lawrence Olson

Dissertations (1934 -)

NMR-based methods used in conjunction with a technique called docking are used to characterize ligand binding to proteins. Standard NMR methods were used to study the backbone dynamics of substrate binding to phosphomevalonate kinase (PMK) and it was observed that ligand binding caused PMK to undergo large conformational changes. These changes were reflected by the appearance of many chemical shift changes upon binding of the natural substrates of PMK (both the binary and ternary complexes) in 1H-15N HSQC NMR titration experiments. The same process was used to characterize the effect ligand binding has on the many arginines in the active …

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Modeling And Simulation On Signatures Of Mars Minerals, Widad Elmahboub, Edward Yankey, Olivia Kerwin Oct 2010

Modeling And Simulation On Signatures Of Mars Minerals, Widad Elmahboub, Edward Yankey, Olivia Kerwin

Virginia Journal of Science

The objective of this study was to assess the feasibility of identifying minerals on Mars using remotely sensed data. In the process we also investigated the effect of noise of Aerosol and dust particles on the spectra of Mars minerals. The remotely sensed data was obtained through modeling and simulation and compared to the lab spectroscopy of the specific minerals in order to make an accurate identification. A linear model was developed using MATLAB Random Number Generator to obtain a simulated image. Part of the information we needed for the linear model was pure pixel information of Mars which was …

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Wave Heights During Hurricane Katrina: An Evaluation Of Ppp And Ppk Measurements Of The Vertical Displacement Of The Gps Antenna, Stephan D. Howden, David Dodd, Leslie C. Bender Iii, Norman Guinasso, Josh Kohut Oct 2010

Wave Heights During Hurricane Katrina: An Evaluation Of Ppp And Ppk Measurements Of The Vertical Displacement Of The Gps Antenna, Stephan D. Howden, David Dodd, Leslie C. Bender Iii, Norman Guinasso, Josh Kohut

Faculty Publications

In August 2005 the eye of Hurricane Katrina passed 49 n mi to the west of a 3-m discus buoy operated by the Central Gulf of Mexico Ocean Observing System (CenGOOS). Buoy motions were measured with a strapped-down 6 degrees of freedom accelerometer, a three-axis magnetometer, and a survey-grade GPS receiver. The significant wave heights were computed from the buoy's accelerometer record and from the dual-frequency GPS measurements that were processed in two different ways. The first method was postprocessed kinematic (PPK) GPS, which requires another GPS receiver at a fixed known location, and the other was precise point positioning …

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Sharp Weighted Estimates For Classical Operators [Post-Print], David Cruz-Uribe Sfo, José María Martell, Carlos Perez Oct 2010

Sharp Weighted Estimates For Classical Operators [Post-Print], David Cruz-Uribe Sfo, José María Martell, Carlos Perez

Faculty Scholarship

See abstract at: http://www.sciencedirect.com/science/article/pii/S0001870811003136

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Synthesis And Thermoelectric Properties Of Bi2se3 Nanostructures, K. Kadel, Latha Kumari, Wz Li, Jiang Yu Huang, Paula P. Provencio Oct 2010

Synthesis And Thermoelectric Properties Of Bi2se3 Nanostructures, K. Kadel, Latha Kumari, Wz Li, Jiang Yu Huang, Paula P. Provencio

Department of Physics

Bismuth selenide (Bi2Se3) nanostructures were synthesized via solvothermal method. The crystallinity of the as-synthesized sample has been analyzed by X-ray diffraction, which shows the formation of rhombohedral Bi2Se3. Electron microscopy examination indicates that the Bi2Se3 nanoparticles have hexagonal flake-like shape. The effect of the synthesis temperature on the morphology of the Bi2Se3 nanostructures has also been investigated. It is found that the particle size increases with the synthesis temperature. Thermoelectric properties of the Bi2Se3 nanostructures were also measured, and the maximum value of dimensionless figure of merit (ZT) of 0.096 was obtained at 523 K.

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Measurement Of Beauty Production In Dis And F2Bb̄ Extraction At Zeus: The Zeus Collaboration, H. Abramowicz, I. Abt, L. Adamczyk, M. Adamus, R. Aggarwal, S. Antonelli, P. Antonioli, A. Antonov, M. Arneodo, V. Aushev, Y. Aushev, O. Bachynska, A. Bamberger, A. N. Barakbaev, G. Barbagli, G. Bari, F. Barreiro, D. Bartsch, M. Basile, O. Behnke, J. Behr, U. Behrens, L. Bellagamba, A. Bertolin, S. Bhadra, M. Bindi, C. Blohm, T. Bold, E. G. Boos, M. Borodin, K. Borras, Margarita C. K. Mattingly Oct 2010

Measurement Of Beauty Production In Dis And F2Bb̄ Extraction At Zeus: The Zeus Collaboration, H. Abramowicz, I. Abt, L. Adamczyk, M. Adamus, R. Aggarwal, S. Antonelli, P. Antonioli, A. Antonov, M. Arneodo, V. Aushev, Y. Aushev, O. Bachynska, A. Bamberger, A. N. Barakbaev, G. Barbagli, G. Bari, F. Barreiro, D. Bartsch, M. Basile, O. Behnke, J. Behr, U. Behrens, L. Bellagamba, A. Bertolin, S. Bhadra, M. Bindi, C. Blohm, T. Bold, E. G. Boos, M. Borodin, K. Borras, Margarita C. K. Mattingly

Faculty Publications

Beauty production in deep inelastic scattering with events in which a muon and a jet are observed in the final state has been measured with the ZEUS detector at HERA using an integrated luminosity of 114 pb-1. The fraction of events with beauty quarks in the data was determined using the distribution of the transverse momentum of the muon relative to the jet. The cross section for beauty production was measured in the kinematic range of photon virtuality, Q2>2 GeV2, and inelasticity, 0.05

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Jahn-Teller Coupling And Fragmentation After Core-Shell Excitation Ini Cf4 Investigated By Partial-Ion-Yield Spectroscopy, Renaud Guillemin, Wayne C. Stolte, Maria Novella Piancastelli, Dennis W. Lindle Oct 2010

Jahn-Teller Coupling And Fragmentation After Core-Shell Excitation Ini Cf4 Investigated By Partial-Ion-Yield Spectroscopy, Renaud Guillemin, Wayne C. Stolte, Maria Novella Piancastelli, Dennis W. Lindle

Chemistry and Biochemistry Faculty Research

We investigate fragmentation processes induced by core-level photoexcitation in CF4 at both the carbon and fluorine K edges by means of partial-ion-yield spectroscopy. The molecule CF4 is a textbook example of systems in which Jahn-Teller coupling strongly manifests itself in the photoabsorption spectrum. Spectral features related to Jahn-Teller and quasi-Jahn-Teller splitting are observed, and important differences in the fragmentation pathways are revealed depending on the symmetries of the core-excited states. We interpret these experimental observations on the grounds of symmetry lowering from the Td to the C3v point group as well as preferential orientation with respect …

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Determination Of Threshold Exposure And Intensity For Recording Holograms In Thick Green-Sensitive Acrylamide-Based Photopolymer, Mohammad Sultan Mahmud, Izabela Naydenova, Tzwetanka Bebeva, Raghavendra Jallapuram, Suzanne Martin, Vincent Toal Oct 2010

Determination Of Threshold Exposure And Intensity For Recording Holograms In Thick Green-Sensitive Acrylamide-Based Photopolymer, Mohammad Sultan Mahmud, Izabela Naydenova, Tzwetanka Bebeva, Raghavendra Jallapuram, Suzanne Martin, Vincent Toal

Articles

For optical data storage applications, it is essential to determine the lowest intensity (also known as threshold intensity) below or at which no data page or grating can be recorded in the photosensitive material, as this in turn determines the data capacity of the material. Here, experiments were carried out to determine the threshold intensity below which the formation of a simple hologram—a holographic diffraction grating in a green-sensitized acrylamide-based photopolymer—is not possible. Two main parameters of the recording layers—dye concentration and thickness—were varied to study the influence of the density of the generated free radicals on the holographic properties …

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Tabor To The River: An Evaluation Of Outreach Efforts And Opportunities For Engaging Residents In Stormwater Management, Vivek Shandas, Anne Nelson, Carine Arendes, Cathy Cibor Oct 2010

Tabor To The River: An Evaluation Of Outreach Efforts And Opportunities For Engaging Residents In Stormwater Management, Vivek Shandas, Anne Nelson, Carine Arendes, Cathy Cibor

Institute for Sustainable Solutions Publications and Presentations

This report summarizes the key findings from a neighborhood survey that focused on household perceptions of sustainable stormwater systems. The survey was conducted in collaboration with the City of Portland?s Bureau of Environmental Services (BES) and Portland State University?s Center for Urban Studies.

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Secureangle: Improving Wireless Security Using Angle-Of-Arrival Information, Jie Xiong, Kyle Jamieson Oct 2010

Secureangle: Improving Wireless Security Using Angle-Of-Arrival Information, Jie Xiong, Kyle Jamieson

Research Collection School Of Computing and Information Systems

Wireless networks play an important role in our everyday lives, at the workplace and at home. However, they are also relatively vulnerable: physically located off site, attackers can circumvent wireless security protocols such as WEP, WPA, and even to some extent WPA2, presenting a security risk to the entire network. To address this problem, we propose SecureAngle, a system designed to operate alongside existing wireless security protocols, adding defense in depth. SecureAngle leverages multi-antenna APs to profile the directions at which a client's signal arrives, using this angle-of-arrival (AoA) information to construct signatures that uniquely identify each client. We identify …

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Cast2face: Character Identification In Movie With Actor-Character Correspondence, Mengdi Xu, Xiaotong Yuan, Jialie Shen, Shuicheng Yan Oct 2010

Cast2face: Character Identification In Movie With Actor-Character Correspondence, Mengdi Xu, Xiaotong Yuan, Jialie Shen, Shuicheng Yan

Research Collection School Of Computing and Information Systems

We investigate the problem of automatically identifying characters in a movie with the supervision of actor-character name correspondence provided by the movie cast. Our proposed framework, namely Cast2Face, is featured by: (i) we restrict the names to assign within the set of character names in the cast; (ii) for each character, by using the corresponding actor's name as a key word, we retrieve from Google image search a group of face images to form the gallery set; and (iii) the probe face tracks in the movie are then identified as one of the actors by robust multi-task joint sparse representation …

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Finding Unusual Review Patterns Using Unexpected Rules, Nitin Jindal, Bing Liu, Ee Peng Lim Oct 2010

Finding Unusual Review Patterns Using Unexpected Rules, Nitin Jindal, Bing Liu, Ee Peng Lim

Research Collection School Of Computing and Information Systems

In recent years, opinion mining attracted a great deal of research attention. However, limited work has been done on detecting opinion spam (or fake reviews). The problem is analogous to spam in Web search [1, 9 11]. However, review spam is harder to detect because it is very hard, if not impossible, to recognize fake reviews by manually reading them [2]. This paper deals with a restricted problem, i.e., identifying unusual review patterns which can represent suspicious behaviors of reviewers. We formulate the problem as finding unexpected rules. The technique is domain independent. Using the technique, we analyzed an Amazon.com …

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Jointly Modeling Aspects And Opinions With A Maxent-Lda Hybrid, Xin Zhao, Jing Jiang, Hongfei Yan, Xiaoming Li Oct 2010

Jointly Modeling Aspects And Opinions With A Maxent-Lda Hybrid, Xin Zhao, Jing Jiang, Hongfei Yan, Xiaoming Li

Research Collection School Of Computing and Information Systems

Discovering and summarizing opinions from online reviews is an important and challenging task. A commonly-adopted framework generates structured review summaries with aspects and opinions. Recently topic models have been used to identify meaningful review aspects, but existing topic models do not identify aspect-specific opinion words. In this paper, we propose a MaxEnt-LDA hybrid model to jointly discover both aspects and aspect-specific opinion words. We show that with a relatively small amount of training data, our model can effectively identify aspect and opinion words simultaneously. We also demonstrate the domain adaptability of our model.

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