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Detection of B-Mode Polarization in the Cosmic Microwave Background with Data from the South Pole Telescope

Physical Review Letters 2013年第14期111卷 141301-141301页

作者： D. Hanson S. Hoover A. Crites P. A. R. Ade K. A. Aird J. E. Austermann J. A. Beall A. N. Bender B. A. Benson L. E. Bleem J. J. Bock J. E. Carlstrom C. L. Chang H. C. Chiang H-M. Cho A. Conley T. M. Crawford T. de Haan M. A. Dobbs W. Everett J. Gallicchio J. Gao E. M. George N. W. Halverson N. Harrington J. W. Henning G. C. Hilton G. P. Holder W. L. Holzapfel J. D. Hrubes N. Huang J. Hubmayr K. D. Irwin R. Keisler L. Knox A. T. Lee E. Leitch D. Li C. Liang D. Luong-Van G. Marsden J. J. McMahon J. Mehl S. S. Meyer L. Mocanu T. E. Montroy T. Natoli J. P. Nibarger V. Novosad S. Padin C. Pryke C. L. Reichardt J. E. Ruhl B. R. Saliwanchik J. T. Sayre K. K. Schaffer B. Schulz G. Smecher A. A. Stark K. T. Story C. Tucker K. Vanderlinde J. D. Vieira M. P. Viero G. Wang V. Yefremenko O. Zahn M. Zemcov Department of Physics McGill University Montreal Quebec H3A 2T8 Canada Kavli Institute for Cosmological Physics University of Chicago Chicago Illinois 60637 USA Enrico Fermi Institute University of Chicago Chicago Illinois 60637 USA Department of Astronomy and Astrophysics University of Chicago Chicago Illinois 60637 USA School of Physics and Astronomy Cardiff University Cardiff CF24 3YB United Kingdom University of Chicago Chicago Illinois 60637 USA Department of Astrophysical and Planetary Sciences CASA University of Colorado 389 UCB Boulder Colorado 80309 USA National Institute of Standards and Technology Boulder Colorado 80305 USA Department of Physics University of Chicago Chicago Illinois 60637 USA California Institute of Technology Pasadena California 91125 USA Jet Propulsion Laboratory Pasadena California 91109 USA High Energy Physics Division Argonne National Laboratory Argonne Illinois 60439 USA School of Mathematics Statistics and Computer Science University of KwaZulu-Natal Durban 4000 South Africa Department of Physics University of California Berkeley California 94720 USA Department of Physics University of Colorado Boulder Colorado 80309 USA Department of Physics University of California Davis California 95616 USA Physics Division Lawrence Berkeley National Laboratory Berkeley California 94720 USA Department of Physics and Astronomy University of British Columbia Vancouver British Columbia V6T 1Z1 Canada Department of Physics University of Michigan Ann Arbor Michigan 48109 USA Physics Department Case Western Reserve University Cleveland Ohio 44106 USA Materials Science Division Argonne National Laboratory Argonne Illinois 60439 USA Department of Physics University of Minnesota Minneapolis Minnesota 55455 USA Liberal Arts Department School of the Art Institute of Chicago Chicago Illinois 60603 USA Infrared Processing and Analysis Center California Institute of Technology JPL Pasadena California 91125 USA Ha

Gravitational lensing of the cosmic microwave background generates a curl pattern in the observed polarization. This “B-mode” signal provides a measure of the projected mass distribution over the entire observable Universe and also acts as a contaminant for the measurement of primordial gravity-wave signals. In this Letter we present the first detection of gravitational lensing B modes, using first-season data from the polarization-sensitive receiver on the South Pole Telescope (SPTpol). We construct a template for the lensing B-mode signal by combining E-mode polarization measured by SPTpol with estimates of the lensing potential from a Herschel-SPIRE map of the cosmic infrared background. We compare this template to the B modes measured directly by SPTpol, finding a nonzero correlation at 7.7σ significance. The correlation has an amplitude and scale dependence consistent with theoretical expectations, is robust with respect to analysis choices, and constitutes the first measurement of a powerful cosmological observable.

关键词： POLARIZATION (Nuclear physics) RESEARCH COSMIC background radiation GRAVITATIONAL lenses COSMOLOGY

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Unobtrusive online monitoring of sleep at home

Unobtrusive online monitoring of sleep at home

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Annual International Conference of the IEEE Engineering in Medicine and Biology Society (EMBC)

作者： Joonas Paalasmaa Mikko Waris Hannu Toivonen Lasse Leppäkorpi Markku Partinen Department of Signal Processing Tampere University of Technology Tampere Finland Department of Computer Science University of Helsinki Helsinki Finland *** Limited Espoo Finland Department of Clinical Neurosciences Helsinki University of Central Hospital Helsinki Finland

We describe an online sleep monitoring service, based on unobtrusive ballistocardiography (BCG) measurement in an ordinary bed. The novelty of the system is that the sleep tracking web application is based on measurements from a fully unobtrusive sensor. The BCG signal is measured with a piezoelectric film sensor under the mattress topper, and sent to the web server for analysis. Heart rate and respiratory variation, activity, sleep stages, and stress reactions are inferred based on the signal. The sleep information is presented to the user along with measurements of the sleeping environment (temperature, noise, luminosity) and user-logged tags (e.g. stress, alcohol, exercise). The approach is designed for long-term use at home, allowing users to follow the development of their sleep over months and years. The service has also a medical use, as sleep disorder patients can be measured for long periods before and after interventions.

关键词： Sleep apnea Heart rate variability Monitoring Stress Temperature measurement

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Developing discrete density Hidden Markov Models for Arabic printed text recognition

Developing discrete density Hidden Markov Models for Arabic ...

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IEEE International Conference on Computational Intelligence and Cybernetics (CyberneticsCom)

作者： Sameh M. Awaida Mohammad S. Khorsheed Computer engineering department Qassim University Qassim K.S.A Image Processing and Signal Analysis & Recognition King Abdul-Aziz City for Science and Technology Riyadh K.S.A

In this paper, a technique for the recognition of unconstrained Arabic printed text is proposed. Features that measure the image characteristics at local scales are applied. A line image is divided into a set of one-pixel width windows which is sliding a cross that text line. Run length encoding is used to extract features from each window. A unique method is chosen to select best number of transitions for each window. The proposed recognition system is trained and tested on the APTI (Arabic Printed Text Image) database. In order to select the optimal parameters for feature extraction and for the HMM classifier, the APTI training dataset is further divided into a smaller training subset and a verification set. The estimated parameters are, then, used in the testing phase. The presented technique provides state-of-the-art recognition results on the APTI database using HMMs. The achieved average recognition rates is 96.65% on the letter level using the HMM classifier.

关键词： Hidden Markov models Text recognition Databases Feature extraction Training Vectors Testing

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Moving shadow detection by nonlinear Tone-Mapping

Moving shadow detection by nonlinear Tone-Mapping

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International Conference on Systems, Signals and Image processing, IWSSIP

作者： Elad Bullkich Idan Ilan Yair Moshe Yacov Hel-Or Hagit Hel-Or Signal and Image Processing Laboratory (SIPL) Department of Electrical Engineering Technion-Israel Institute of Technology Haifa Israel Google Inc. Mountain View USA Department of Computer Science University of Haifa Haifa Israel

Shadow detection is a well-known problem in image and video processing. Detecting moving shadows is useful in numerous applications such as object detection and tracking. Most works in this area are not suitable for shadow detection using a low-cost outdoor surveillance camera. In this work we suggest a fast shadow detection approach for video surveillance, by comparing each video frame to a continuously updated background image. We differentiate shadow areas from foreground areas by assuming the shadow pixels are associated with background pixels through a nonlinear tone mapping. This assumption is general and applies to various systems and scene conditions. A distance measure between patch images that account for nonlinear tone mapping is calculated by adapting a recently suggested approach for pattern matching termed Matching by Tone Mapping (MTM). We show that the proposed technique is computationally efficient and outperforms state-of-the-art shadow detection techniques in typical surveillance scenarios.

关键词： Surveillance Measurement Image color analysis Cameras Robustness Lighting

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VIQI: A new approach for visual interpretation of deep web query interfaces

VIQI: A new approach for visual interpretation of deep web q...

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International Conference on Information technology and e-Services (ICITeS)

作者： Radhouane Boughammoura Lobna Hlaoua Mohamed Nazih Omri Department of Sciences of Data Processing Faculty of Sciences of Monastir Research Unit MARS Monastir Tunisia Department of Electronic and Computer Science High School of Sciences and Technology of H.Sousse Research Unit MARS Tunisia

Deep Web databases contain more than 90% of pertinent information of the Web. Despite their importance, users don't profit of this treasury. Many deep web services are offering competitive services in term of prices, quality of service, and facilities. As the number of services is growing rapidly, users have difficulty to ask many web services in the same time. In this paper, we imagine a system where users have the possibility to formulate one query using one query interface and then the system translates query to the rest of query interfaces. However, interfaces are created by designers in order to be interpreted visually by users, machines can not interpret query from a given interface. We propose a new approach which emulates capacity of interpretation of users and extracts query from deep web query interfaces. Our approach has proved good performances on two standard datasets.

关键词： Web services Visualization Web pages Semantics Feature extraction Standards Noise

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Saliency-Based Fidelity Adaptation Preprocessing for Video Coding

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Journal of computer science & technology 2011年第1期26卷 195-202页

作者：卢少平张松海 Department of Computer Science and Technology Tsinghua University Beijing Engineering Research Center for Intelligent Processing of Visual Media and Content Security

In this paper, we present a video coding scheme which applies the technique of visual saliency computation to adjust image fidelity before compression. To extract visually salient features, we construct a spatio-temporal saliency map by analyzing the video using a combined bottom-up and top-down visual saliency model. We then use an extended bilateral filter, in which the local intensity and spatial scales are adjusted according to visual saliency, to adaptively alter the image fidelity. Our implementation is based on the H.264 video encoder JM12.0. Besides evaluating our scheme with the H.264 reference software, we also compare it to a more traditional foreground-background segmentation-based method and a foveation-based approach which employs Gaussian blurring. Our results show that the proposed algorithm can improve the compression ratio significantly while effectively preserving perceptual visual quality.

关键词： visual saliency bilateral filter fidelity adjustment region-of-interest encoder

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Multimodal biometric person recognition system based on fingerprint & Finger-Knuckle-Print using correlation filter classifier

Multimodal biometric person recognition system based on fing...

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IEEE International Conference on Communications (ICC)

作者： Abdallah Meraoumia Salim Chitroub Ahmed Bouridane Signal and Image Processing Laboratory Electronics and Computer Science Faculty University of Sciences and Technology Houari Boumediene Algiers Algeria Department of Computer Science King Saud University Riyadh Saudi Arabia School of Computing Engineering and Information Sciences Northumbria University Newcastle-upon-Tyne UK

ISBN: (纸本)9781457720529

Biometrics is an effective technology for personnel identity recognition, but uni-modal biometric systems which use a single trait for recognition will suffer from problems like noisy sensor data, non-universality, lack of distinctiveness of the biometric trait, and spoof attacks. These problems can be tackled by using multi-biometrics in the system. Hand-based person recognition provides a reliable, low-cost and user-friendly viable solution for a range of access control applications. As one of the most popular biometric traits, fingerprints (FP) are widely used in personal recognition. However, a novel hand-based biometric feature, Finger-Knuckle-Print (FKP), has attracted an increasing amount of attention. In this paper, FP and FKP are integrated in order to construct an efficient multi-biometric recognition system based on matching score level and image level fusion. In this study we use the minimum average correlation energy (MACE) and Unconstrained MACE (UMACE) filters in conjunction with two correlation plane performance measures, max peak value and peak-to-sidelobe ratio, to determine the effectiveness of this method. The experimental results showed that the designed system achieves an excellent recognition rate on the Hong Kong polytechnic university (PolyU) FKP and high resolution fingerprint database.

关键词： Correlation Databases Training Discrete wavelet transforms Biomedical imaging Biometrics (access control) Fingers

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Betweenness-based algorithm for a partition scale-free graph

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Chinese Physics B 2011年第11期20卷 556-564页

作者：张百达吴俊杰唐玉华周静 National Laboratory for Parallel and Distributed Processing School of ComputersNational University of Defense Technology Department of Computer Science and Technology School of ComputersNational University of Defense Technology

Many real-world networks are found to be scale-free. However, graph partition technology, as a technology capable of parallel computing, performs poorly when scale-free graphs are provided. The reason for this is that traditional partitioning algorithms are designed for random networks and regular networks, rather than for scale-free networks. Multilevel graph-partitioning algorithms are currently considered to be the state of the art and are used extensively. In this paper, we analyse the reasons why traditional multilevel graph-partitioning algorithms perform poorly and present a new multilevel graph-partitioning paradigm, top down partitioning, which derives its name from the comparison with the traditional bottom-up partitioning. A new multilevel partitioning algorithm, named betweenness-based partitioning algorithm, is also presented as an implementation of top-down partitioning paradigm. An experimental evaluation of seven different real-world scale-free networks shows that the betweenness-based partitioning algorithm significantly outperforms the existing state-of-the-art approaches.

关键词： graph partitioning betweenness-based partitioning algorithm scale free network

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Mobile TV with Long Time Interleaving and Fast Zapping

Mobile TV with Long Time Interleaving and Fast Zapping

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IEEE International Conference on Multimedia and Expo Workshops (ICMEW)

作者： Cornelius Hellge Valentina Pullano Manuel Hensel Giovanni E. Corazza Thomas Schierl Thomas Wiegand Image Communication Laboratory Berlin Institute of Technology Berlin Germany Multimedia Communications Group Image Processing Department Fraunhofer HHI Berlin Germany Department of Electronics Computer Science and Systems Faculty of Engineering University of Bologna Bologna Italy

The main challenge for provisioning of Mobile TV services is to overcome long burst errors as are often found in mobile reception conditions. Long time interleaving can be implemented by means of Application Layer FEC (AL-FEC) to increase the time diversity of the signal and thereby its robustness against burst errors. The main obstacle of long time interleaving for streaming services is the increase in service tune-in time, which significantly decreases the Quality of Experience (QoE) of end users. That is why today's Mobile TV systems are provisioned in a way to minimize the time interleaving length to provide an acceptable tune-in time, though the service robustness would significantly benefit from a longer interleaving length. This paper presents a new way of service provisioning that marries fast zapping and long time interleaving by combining Layer-Aware FEC and layered media codecs with unequal time interleaving and an appropriate transmission scheduling. The effect of the proposed scheme on the QoE as well as the service tune-in time is analyzed. Simulation results within a Gilbert-Elliot channel report the benefit of the proposed scheme, which for the first time enables broadcast services with fast tune-in and at the same time long time interleaving.

关键词： Forward error correction Static VAr compensators Media Streaming media Decoding Delay Robustness

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Conservation laws for variable coefficient nonlinear wave equations with power nonlinearities

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Chinese Physics B 2011年第7期20卷 22-27页

作者：黄定江周水庚杨勤民 Department of Mathematics East China University of Science and Technology School of Computer Science Fudan University Shanghai Key Laboratory of Intelligent Information Processing Fudan University

Conservation laws for a class of variable coefficient nonlinear wave equations with power nonlinearities are investigated. The usual equivalence group and the generalized extended one including transformations which are nonlocal with respect to arbitrary elements are introduced. Then, using the most direct method, we carry out a classification of local conservation laws with characteristics of zero order for the equation under consideration up to equivalence relations generated by the generalized extended equivalence group. The equivalence with respect to this group and the correct choice of gauge coefficients of the equations play the major roles for simple and clear formulation of the final results.

关键词： nonlinear wave equations conservation laws equivalence group symmetries

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