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2013

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Articles 1231 - 1260 of 11462

Full-Text Articles in Physical Sciences and Mathematics

Second Order Online Collaborative Filtering, Jing Lu, Steven C. H. Hoi, Jialei Wang, Peilin Zhao Nov 2013

Second Order Online Collaborative Filtering, Jing Lu, Steven C. H. Hoi, Jialei Wang, Peilin Zhao

Research Collection School Of Computing and Information Systems

Collaborative Filtering (CF) is one of the most successful learning techniques in building real-world recommender systems. Traditional CF algorithms are often based on batch machine learning methods which suffer from several critical drawbacks, e.g., extremely expensive model retraining cost whenever new samples arrive, unable to capture the latest change of user preferences over time, and high cost and slow reaction to new users or products extension. Such limitations make batch learning based CF methods unsuitable for real-world online applications where data often arrives sequentially and user preferences may change dynamically and rapidly. To address these limitations, we investigate online collaborative …


Search Of Small Objects By Topology Matching, Context Modeling, And Pattern Mining, Wei Zhang, Chong-Wah Ngo Nov 2013

Search Of Small Objects By Topology Matching, Context Modeling, And Pattern Mining, Wei Zhang, Chong-Wah Ngo

Research Collection School Of Computing and Information Systems

No abstract provided.


A Link-Bridged Topic Model For Cross-Domain Document Classification, Pei Yang, Wei Gao, Qi Tan, Kam-Fai Wong Nov 2013

A Link-Bridged Topic Model For Cross-Domain Document Classification, Pei Yang, Wei Gao, Qi Tan, Kam-Fai Wong

Research Collection School Of Computing and Information Systems

Transfer learning utilizes labeled data available from some related domain (source domain) for achieving effective knowledge transformation to the target domain. However, most state-of-the-art cross-domain classification methods treat documents as plain text and ignore the hyperlink (or citation) relationship existing among the documents. In this paper, we propose a novel cross-domain document classification approach called Link-Bridged Topic model (LBT). LBT consists of two key steps. Firstly, LBT utilizes an auxiliary link network to discover the direct or indirect co-citation relationship among documents by embedding the background knowledge into a graph kernel. The mined co-citation relationship is leveraged to bridge the …


Budgeted Personalized Incentive Approaches For Smoothing Congestion In Resource Networks, Pradeep Varakantham, Na Fu, William Yeoh, Shih-Fen Cheng, Hoong Chuin Lau Nov 2013

Budgeted Personalized Incentive Approaches For Smoothing Congestion In Resource Networks, Pradeep Varakantham, Na Fu, William Yeoh, Shih-Fen Cheng, Hoong Chuin Lau

Research Collection School Of Computing and Information Systems

Congestion occurs when there is competition for resources by sel sh agents. In this paper, we are concerned with smoothing out congestion in a network of resources by using personalized well-timed in- centives that are subject to budget constraints. To that end, we provide: (i) a mathematical formulation that computes equilibrium for the re- source sharing congestion game with incentives and budget constraints; (ii) an integrated approach that scales to larger problems by exploiting the factored network structure and approximating the attained equilib- rium; (iii) an iterative best response algorithm for solving the uncon- strained version (no budget) of the …


Social Sensing For Urban Crisis Management: The Case Of Singapore Haze, Philips Kokoh Prasetyo, Ming Gao, Ee Peng Lim, Christie N. Scollon Nov 2013

Social Sensing For Urban Crisis Management: The Case Of Singapore Haze, Philips Kokoh Prasetyo, Ming Gao, Ee Peng Lim, Christie N. Scollon

Research Collection School Of Computing and Information Systems

Sensing social media for trends and events has become possible as increasing number of users rely on social media to share information. In the event of a major disaster or social event, one can therefore study the event quickly by gathering and analyzing social media data. One can also design appropriate responses such as allocating resources to the affected areas, sharing event related information, and managing public anxiety. Past research on social event studies using social media often focused on one type of data analysis (e.g., hashtag clusters, diffusion of events, influential users, etc.) on a single social media data …


Information Vs Interaction: An Alternative User Ranking Model For Social Networks, Wei Xie, Ai Phuong Hoang, Feida Zhu, Ee Peng Lim Nov 2013

Information Vs Interaction: An Alternative User Ranking Model For Social Networks, Wei Xie, Ai Phuong Hoang, Feida Zhu, Ee Peng Lim

Research Collection School Of Computing and Information Systems

The recent years have seen an unprecedented boom of social network services, such as Twitter, which boasts over 200 million users. In such big social platforms, the influential users are ideal targets for viral marketing to potentially reach an audience of maximal size. Most proposed algorithms rely on the linkage structure of the respective underlying network to determine the information flow and hence indicate a users influence. From social interaction perspective, we built a model based on the dynamic user interactions constantly taking place on top of these linkage structures. In particular, in the Twitter setting we supposed a principle …


Understanding The Genetic Makeup Of Linux Device Drivers, Peter Senna Tschudin, Laurent Reveillere, Lingxiao Jiang, David Lo, Julia Lawall Nov 2013

Understanding The Genetic Makeup Of Linux Device Drivers, Peter Senna Tschudin, Laurent Reveillere, Lingxiao Jiang, David Lo, Julia Lawall

Research Collection School Of Computing and Information Systems

No abstract provided.


Constraint-Based Automatic Symmetry Detection, Shao Jie Zhang, Jun Sun, Chengnian Sun, Yang Liu, Junwei Ma, Jin Song Dong Nov 2013

Constraint-Based Automatic Symmetry Detection, Shao Jie Zhang, Jun Sun, Chengnian Sun, Yang Liu, Junwei Ma, Jin Song Dong

Research Collection School Of Computing and Information Systems

We present an automatic approach to detecting symmetry relations for general concurrent models. Despite the success of symmetry reduction in mitigating state explosion problem, one essential step towards its soundness and effectiveness, i.e., how to discover sufficient symmetries with least human efforts, is often either overlooked or oversimplified. In this work, we show how a concurrent model can be viewed as a constraint satisfaction problem (CSP), and present an algorithm capable of detecting symmetries arising from the CSP which induce automorphisms of the model. To the best of our knowledge, our method is the first approach that can automatically detect …


P For Discussion: Naming Superheavy Halogen And Noble Elements, Shawn Burdette, Brett Thornton Oct 2013

P For Discussion: Naming Superheavy Halogen And Noble Elements, Shawn Burdette, Brett Thornton

Shawn C. Burdette

No abstract provided.


Crosslinked Polymer Sheaths For Dispersing Individual Single-Walled Carbon Nanotubes In Nonaqueous Solvents, L. Ojha, M. Tchoul, K. Bastola, K. Ausman Oct 2013

Crosslinked Polymer Sheaths For Dispersing Individual Single-Walled Carbon Nanotubes In Nonaqueous Solvents, L. Ojha, M. Tchoul, K. Bastola, K. Ausman

Kevin D. Ausman

Single-walled carbon nanotubes have been suspended individually in water by encasing them in a thin, uniform layer of the crosslinkable polymer poly (N-vinylpyrrolidone-co-allylamine). When this polymer is crosslinked under dilute conditions, the polymer sheath, formerly stabilized by the hydrophobic effect, becomes stable to changes in the solvent system.


Detrital Zircon Geochronology And Provenance Of The Paleoproterozoic Huron (∼2.4–2.2 Ga) And Animikie (∼2.2–1.8 Ga) Basins, Southern Superior Province, John Craddock, R. Rainbird, W. Davis, L. Heaman, J. Vervoort, C. Davidson, T. Boerboom, A. Konstantinou, S. Vorhies, L. Kerber, R. Lundquist Oct 2013

Detrital Zircon Geochronology And Provenance Of The Paleoproterozoic Huron (∼2.4–2.2 Ga) And Animikie (∼2.2–1.8 Ga) Basins, Southern Superior Province, John Craddock, R. Rainbird, W. Davis, L. Heaman, J. Vervoort, C. Davidson, T. Boerboom, A. Konstantinou, S. Vorhies, L. Kerber, R. Lundquist

John Craddock

No abstract provided.


Fibonacci And Lucas Identities Via Graphs, Joe Demaio, John Jacobson Oct 2013

Fibonacci And Lucas Identities Via Graphs, Joe Demaio, John Jacobson

Joe DeMaio

The Fibonacci number of a graph, defined by Prodinger and Tichy in 1982, is the number of independent sets on the graph. The Fibonacci number of the path graph, P n , is the Fibonacci number F n+2 and the Fibonacci number of the cycle graph, C n , is the Lucas number L n . This paper combines the visual nature of graph theory with combinatorial methods to prove new identities for the Fibonacci and Lucas numbers.


Big History: The Sun: Season 1 Episode 13, Mojgan Behmand Oct 2013

Big History: The Sun: Season 1 Episode 13, Mojgan Behmand

Mojgan Behmand

The Sun is our master and creator. It gives us our perception of time, controls our reality, and powers our lives. Big History sheds new light on our nearest star, revealing that ancient sun worship intersects with science, that our bodies are fine-tuned to the 24-hour day, and history is driven in unseen ways by the simple way we circle our star.


Quantitative Assessment Method Of Illegal Dumping În Small Rivers. Case Study: Neamt County, Romania, Florin C. Mihai Oct 2013

Quantitative Assessment Method Of Illegal Dumping În Small Rivers. Case Study: Neamt County, Romania, Florin C. Mihai

Florin C MIHAI

Poor waste management facilities from Romanian rural areas lead to uncontrolled waste disposal on improper sites. These bad practices are frequently in the the proximity of built-up areas , therefore, the small rivers inside these areas are susceptible to waste dumping. The paper aims to develop a quantitative assessment method of waste disposed into such small rivers from extra Carpathian region of Neamț county. The lack of organized waste collection services from 2003 lead to high values of waste disposed in such rivers frequently over 15 t/yr for each one. Despite some improvements compared to 2003 the small rivers inside …


Hierarchical Vector Auto-Regressive Models And Their Applications To Multi-Subject Effective Connectivity, Cristina Gorrostieta, Mark Fiecas, Hernando Ombao, Erin Burke, Steven Cramer Oct 2013

Hierarchical Vector Auto-Regressive Models And Their Applications To Multi-Subject Effective Connectivity, Cristina Gorrostieta, Mark Fiecas, Hernando Ombao, Erin Burke, Steven Cramer

Mark Fiecas

Vector auto-regressive (VAR) models typically form the basis for constructing directed graphical models for investigating connectivity in a brain network with brain regions of interest (ROIs) as nodes. There are limitations in the standard VAR models. The number of parameters in the VAR model increases quadratically with the number of ROIs and linearly with the order of the model and thus due to the large number of parameters, the model could pose serious estimation problems. Moreover, when applied to imaging data, the standard VAR model does not account for variability in the connectivity structure across all subjects. In this paper, …


The Politics Media Equation:Exposing Two Faces Of Old Nexus Through Study Of General Elections,Wikileaks And Radia Tapes, Ratnesh Dwivedi Mr Oct 2013

The Politics Media Equation:Exposing Two Faces Of Old Nexus Through Study Of General Elections,Wikileaks And Radia Tapes, Ratnesh Dwivedi Mr

Ratnesh Dwivedi

The important identity of a responsible media is playing an unbiased role in reporting a matter without giving unnecessary hype to attract the attention of the gullible public with the object of making money and money only.After reporting properly the media can educate the public to form their own opinion in the matters of public interest. Throughout the centuries, the world has never existed without information and communication, hence the inexhaustible essence of mass media. The government has the power to either make or reject whatever that will exist within its environment. It also determines how free the mass media …


Folding Corners Of The Habits Of Mind, Peter S. Wiles Oct 2013

Folding Corners Of The Habits Of Mind, Peter S. Wiles

Peter S. Wiles

Students fold paper to make and test conjectures while reasoning about and discussing geometric ideas.


Microcalorimetric Study Of Nematic-To-Neat-Soap And Nematic-To-Isotropic Phase Transitions In A Lyotropic Liquid Crystal, T. S. Shin, Satyendra Kumar Oct 2013

Microcalorimetric Study Of Nematic-To-Neat-Soap And Nematic-To-Isotropic Phase Transitions In A Lyotropic Liquid Crystal, T. S. Shin, Satyendra Kumar

Satyendra Kumar

The results of specific-heat measurements at the nematic- (N) to-neat-soap (NS) and nematic-to-isotropic (I) phase transitions in binary mixtures of cesium-perfluoro-octanoate and water are reported. The ratio of specific-heat amplitudes above and below the N-NS transition, A+/A-, and the specific-heat exponent α remain ∼1.0 and ≤0.02, respectively, suggesting 3D XY-type behavior. At the first-order N-I transition, vanishing latent heat and coexistence range at low concentration indicate the existence of a Landau point.


Raman Scattering Study Of Phase Biaxiality In A Thermotropic Bent-Core Nematic Liquid Crystal, Min Sang Park, Beom-Kin Yoon, Jung Ok Park, Veena Prasad, Satyendra Kumar, Mohan Srinivasarao Oct 2013

Raman Scattering Study Of Phase Biaxiality In A Thermotropic Bent-Core Nematic Liquid Crystal, Min Sang Park, Beom-Kin Yoon, Jung Ok Park, Veena Prasad, Satyendra Kumar, Mohan Srinivasarao

Satyendra Kumar

Polarized Raman spectroscopy was used to investigate the development of orientational order and the degree of phase biaxiality in a bent-core mesogenic system. The values of the uniaxial order parameters ⟨P200⟩ and ⟨P400⟩, and biaxial order parameters ⟨P220⟩, ⟨P420⟩, and ⟨P440⟩, and their evolution with temperature were determined. The temperature dependence of almost all order parameters reveals a second order transition from the uniaxial to biaxial nematic phase with ⟨P220⟩ increasing to ∼0.22 before a first order transition to the smectic-C phase, upon cooling.


Morphology And Ordering In Thin Liquid-Crystal Films On Flat Glass Substrates, Yushan Shi, Brian Cull, Satyendra Kumar Oct 2013

Morphology And Ordering In Thin Liquid-Crystal Films On Flat Glass Substrates, Yushan Shi, Brian Cull, Satyendra Kumar

Satyendra Kumar

Results of a high resolution x-ray reflectivity study of growth morphology and ordering of thin liquid-crystal films on flat glass substrate are reported. An adsorbed bilayer of crystalline order, under three dimensional clusters, was found to persist well beyond the nematic to isotropic transition. This adsorbed layer appears to be related to the surface memory effects in liquid-crystal devices. The morphology of these films can be described by the Stranski-Krastanov growth mode.


Parity-Violating Electron Scattering From 4he And The Strange Electric Form Factor Of The Nucleon, K. A. Aniol, Edgar E. Kooijman Oct 2013

Parity-Violating Electron Scattering From 4he And The Strange Electric Form Factor Of The Nucleon, K. A. Aniol, Edgar E. Kooijman

Edgar E Kooijman

We have measured the parity-violating electroweak asymmetry in the elastic scattering of polarized electrons from 4He at an average scattering angle ⟨θlab⟩=5.7° and a four-momentum transfer Q2=0.091  GeV2. From these data, for the first time, the strange electric form factor of the nucleon GEs can be isolated. The measured asymmetry of APV=(6.72±0.84(stat)±0.21(syst))×10-6 yields a value of GEs=-0.038±0.042(stat)±0.010(syst), consistent with zero.


Cholesteric Liquid-Crystal Displays Illuminated By Diffuse And Partially Diffuse Light, W. D. St. John, Z. J. Lu, J. William Doane, Bahman Taheri Oct 2013

Cholesteric Liquid-Crystal Displays Illuminated By Diffuse And Partially Diffuse Light, W. D. St. John, Z. J. Lu, J. William Doane, Bahman Taheri

Bahman Taheri

We report on the photometric and colorimetric properties of surface and polymer network stabilized reflective cholesteric displays. Both diffuse and partially diffuse illumination are used, the latter being an experimental approach to emulating typical room light conditions. It is shown that addition of polymer increases the field of view while decreasing angular dependence of the color quantities: hue, chroma, and lightness. Total luminance and contrast ratio, however, are also decreased. Therefore, it is concluded that optimum polymer concentration is dependent on the viewing geometry. Luminance and contrast ratio of the surface stabilized cells exceeded that of polymer stabilized cell when …


Mechanism Of Unidirectional Liquid-Crystal Alignment On Polyimides With Linearly Polarized Ultraviolet Light Exposure, M. Nishikawa, Bahman Taheri, John L. West Oct 2013

Mechanism Of Unidirectional Liquid-Crystal Alignment On Polyimides With Linearly Polarized Ultraviolet Light Exposure, M. Nishikawa, Bahman Taheri, John L. West

Bahman Taheri

Unidirectional liquid-crystal(LC) alignment by a linearly polarized ultraviolet light(UV) exposure was examined using two types of polyimide (PI). PI with a fluorene unit incorporated in a side chain showed LC alignment perpendicular to those of conventional PIs, i.e., perpendicular to the rubbing direction and parallel to the exposure polarization of UV. The results of the dichroic ratio measurement of LCcells,UVabsorption spectra,birefringence, infrared absorption spectra, and PI conformation calculations using molecular mechanics suggest that the photodecomposition of PI by UV exposure produces anisotropic van der Waals forces, which align LC along its optical axis.


Azimuthal Dependence Of Switching Field Strength For Nematic Liquid Crystal Bistability On Patterned Alignment Layers, Jun-Ichi Niitsuma, Makoto Yoneya, Hiroshi Yokoyama Oct 2013

Azimuthal Dependence Of Switching Field Strength For Nematic Liquid Crystal Bistability On Patterned Alignment Layers, Jun-Ichi Niitsuma, Makoto Yoneya, Hiroshi Yokoyama

Hiroshi Yokoyama

We investigate the azimuthal dependence of the switching field strength for nematic liquid crystal bistability on patterned alignment layers to determine the validity of a switching theory proposed by Kim et al. [Appl. Phys. Lett. 78, 3055 (2001)] and to evaluate higher-order azimuthal anchoring coefficients. Director behavior during switching is described in detail for general azimuthal directions of an applied electric field and the experimental results are explained on the basis of the theory. We obtain azimuthal anchoring coefficients up to the second higher-order term in an expansion of the anchoring energy function. Detailed analysis of the director behavior reveals …


Quantifying Syntectonic Weakening In Deep Orogenic Crust, Christopher Gerbi Oct 2013

Quantifying Syntectonic Weakening In Deep Orogenic Crust, Christopher Gerbi

University of Maine Office of Research Administration: Grant Reports

The primary intellectual impact of this project will be in improving our understanding of the mechanics that shape the Earth's crust. In recent years, earth scientists have used the increasing body of geodetic data towards that end, but the mechanical properties of the middle and lower crust remain only loosely constrained. This project focuses on the magnitude of strain weakening in shear zone networks. In detail, the research will explore the grain-scale and outcrop-scale deformation mechanisms in minerals that lead to this weakening, followed by modeling of the results to understand the weakening process on the larger scale. These conceptual …


The Fierce Green Fire: Vol. 4 Issue 9, Wofford College Environmental Studies Program Oct 2013

The Fierce Green Fire: Vol. 4 Issue 9, Wofford College Environmental Studies Program

The Fierce Green Fire

No abstract provided.


The Santa Clara, 2013-10-31, Santa Clara University Oct 2013

The Santa Clara, 2013-10-31, Santa Clara University

The Santa Clara

No abstract provided.


Interface States In Cofe2o4 Spin-Filter Tunnel Junctions, Pavel V. Lukashev, John D. Burton, Alexander Smogunov, Julian P. Velev, Evgeny Y. Tsymbal Oct 2013

Interface States In Cofe2o4 Spin-Filter Tunnel Junctions, Pavel V. Lukashev, John D. Burton, Alexander Smogunov, Julian P. Velev, Evgeny Y. Tsymbal

Evgeny Tsymbal Publications

Spin-filter tunneling is a promising way to generate highly spin-polarized current, a key component for spintronics applications. In this paper we explore the tunneling conductance across the spin-filter material CoFe2O4 interfaced with Au electrodes, a geometry which provides nearly perfect lattice matching at the CoFe2O4/Au(001) interface. Using density functional theory calculations we demonstrate that interface states play a decisive role in controlling the transport spin polarization in this tunnel junction. For a realistic CoFe2O4 barrier thickness, we predict a tunneling spin polarization of about −60%. We show that this value …


Laser Vaporization Methods For The Synthesis Of Metal And Semiconductor Nanoparticles; Graphene, Doped Graphene And Nanoparticles Supported On Graphene, Parichehr Afshani Oct 2013

Laser Vaporization Methods For The Synthesis Of Metal And Semiconductor Nanoparticles; Graphene, Doped Graphene And Nanoparticles Supported On Graphene, Parichehr Afshani

Theses and Dissertations

The major objective of the research described in this dissertation is the development of new laser vaporization methods for the synthesis of metal and semiconductor nanoparticles, graphene, B- and N-doped graphene, and metal and semiconductor nanoparticles supported on graphene. These methods include the Laser Vaporization Controlled Condensation (LVCC) approach, which has been used in this work for the synthesis of: (1) gold nanoparticles supported on ceria and zirconia nanoparticles for the low temperature oxidation of carbon monoxide, and (2) graphene, boron- and nitrogen-doped graphene, hydrogen-terminated graphene (HTG), metal nanoparticles supported on graphene, and graphene quantum dots. The gold nanoparticles supported …


Mri Characterization Of Radiation Necrosis In An Animal Model: Time To Onset, Progression, And Therapeutic Response, Xiaoyu Jiang Oct 2013

Mri Characterization Of Radiation Necrosis In An Animal Model: Time To Onset, Progression, And Therapeutic Response, Xiaoyu Jiang

All Theses and Dissertations (ETDs)

Radiation necrosis is a severe, but late occurring type of injury to normal tissue, within and surrounding a radiation treatment field, which can lead to significant complications for neurooncology patients. Radiation necrosis is difficult to distinguish from recurrent tumor by either neurologic examination or clinical imaging protocols. Concerns for the development of radiation necrosis often limit therapeutic radiation doses. Current treatment options for radiation necrosis are limited. The development of solutions to these clinical challenges has been hampered by an appropriate animal model of radiation necrosis.

With a novel mouse model of radiation necrosis developed in our lab employing a …