1,493 research outputs found

    Beyond Context: Exploring Semantic Similarity for Tiny Face Detection

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    © 2018 IEEE. Tiny face detection aims to find faces with high degrees of variability in scale, resolution and occlusion in cluttered scenes. Due to the very little information available on tiny faces, it is not sufficient to detect them merely based on the information presented inside the tiny bounding boxes or their context. In this paper, we propose to exploit the semantic similarity among all predicted targets in each image to boost current face detectors. To this end, we present a novel framework to model semantic similarity as pairwise constraints within the metric learning scheme, and then refine our predictions with the semantic similarity by utilizing the graph cut techniques. Experiments conducted on three widely-used benchmark datasets have demonstrated the improvement over the-state-of-the-arts gained by applying this idea

    Beyond context: Exploring semantic similarity for small object detection in crowded scenes

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    © 2019 Small object detection in crowded scene aims to find those tiny targets with very limited resolution from crowded scenes. Due to very little information available on tiny objects, it is often not suitable to detect them merely based on the information presented inside their bounding boxes, resulting low accuracy. In this paper, we propose to exploit the semantic similarity among all predicted objects’ candidates to boost the performance of detectors when handling tiny objects. For this purpose, we construct a pairwise constraint to depict such semantic similarity and propose a new framework based on Discriminative Learning and Graph-Cut techniques. Experiments conducted on three widely used benchmark datasets demonstrate the improvement over the state-of-the-art approaches gained by applying this idea

    Entanglement distillation using particle statistics

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    We extend the idea of entanglement concentration for pure states(Phys. Rev. Lett. {\bf 88}, 187903) to the case of mixed states. The scheme works only with particle statistics and local operations, without the need of any other interactions. We show that the maximally entangled state can be distilled out when the initial state is pure, otherwise the entanglement of the final state is less than one. The distillation efficiency is a product of the diagonal elements of the initial state, it takes the maximum 50%, the same as the case for pure states.Comment: 3 pages, 1 figur

    Anisotropic Magnetotransport and Exotic Longitudinal Linear Magnetoresistance in WTe2 Crystals

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    WTe2 semimetal, as a typical layered transition-metal dichalcogenide, has recently attracted much attention due to the extremely large, non-saturating parabolic magnetoresistance in perpendicular field. Here, we report a systematic study of the angular dependence of the magnetoresistance in WTe2 single crystal. The violation of the Kohler rule and a significant anisotropic magnetotransport behavior in different magnetic field directions are observed. Surprisingly, when the applied field is parallel to the tungsten chains of WTe2, an exotic large longitudinal linear magnetoresistance as high as 1200% at 15 T and 2 K is identified. Violation of the Kohler rule in transverse magnetoresistance can be understood based on a dual effect of the excitons formation and thermal activation, while large longitudinal linear magnetoresistance reflects perfectly the scattering and nesting of quasi-1D nature of this balanced hole-electron system. Our work will stimulate studies of such double-carrier correlated material and corresponding quantum physics

    Measurements of the Cross Section for e+e- -> hadrons at Center-of-Mass Energies from 2 to 5 GeV

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    We report values of R=σ(e+e−→hadrons)/σ(e+e−→Ό+Ό−)R = \sigma(e^+e^-\to {hadrons})/\sigma(e^+e^-\to\mu^+\mu^-) for 85 center-of-mass energies between 2 and 5 GeV measured with the upgraded Beijing Spectrometer at the Beijing Electron-Positron Collider.Comment: 5 pages, 3 figure

    Measurement of ψ(2S)\psi(2S) decays to baryon pairs

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    A sample of 3.95M ψ(2S)\psi(2S) decays registered in the BES detector are used to study final states containing pairs of octet and decuplet baryons. We report branching fractions for ψ(2S)→ppˉ\psi(2S)\to p\bar{p}, ΛΛˉ\Lambda\bar{\Lambda}, ÎŁ0Σˉ0\Sigma^0\bar{\Sigma}{}^0, Ξ−Ξˉ+\Xi^-\bar{\Xi}{}^+, Δ++Δˉ−−\Delta^{++}\bar{\Delta}{}^{--}, ÎŁ+(1385)Σˉ−(1385)\Sigma^+(1385)\bar{\Sigma}{}^-(1385), Ξ0(1530)Ξˉ0(1530)\Xi^0(1530)\bar{\Xi}{}^0(1530), and Ω−Ωˉ+\Omega^-\bar{\Omega}{}^+. These results are compared to expectations based on the SU(3)-flavor symmetry, factorization, and perturbative QCD.Comment: 22 pages, 21 figures, 4 table

    First Measurement of the Branching Fraction of the Decay psi(2S) --> tau tau

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    The branching fraction of the psi(2S) decay into tau pair has been measured for the first time using the BES detector at the Beijing Electron-Positron Collider. The result is Bττ=(2.71±0.43±0.55)×10−3B_{\tau\tau}=(2.71\pm 0.43 \pm 0.55) \times 10^{-3}, where the first error is statistical and the second is systematic. This value, along with those for the branching fractions into e+e- and mu+mu of this resonance, satisfy well the relation predicted by the sequential lepton hypothesis. Combining all these values with the leptonic width of the resonance the total width of the psi(2S) is determined to be (252±37)(252 \pm 37) keV.Comment: 9 pages, 2 figure

    Measurement of the Total Cross Section for Hadronic Production by e+e- Annihilation at Energies between 2.6-5 Gev

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    Using the upgraded Beijing Spectrometer (BESII), we have measured the total cross section for e+e−e^+e^- annihilation into hadronic final states at center-of-mass energies of 2.6, 3.2, 3.4, 3.55, 4.6 and 5.0 GeV. Values of RR, σ(e+e−→hadrons)/σ(e+e−→Ό+Ό−)\sigma(e^+e^-\to {hadrons})/\sigma(e^+e^-\to\mu^+\mu^-), are determined.Comment: Submitted to Phys. Rev. Let

    Measurement of the Inclusive Charm Cross Section at 4.03 GeV and 4.14 GeV

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    The cross section for charmed meson production at s=4.03\sqrt{s} = 4.03 and 4.14 GeV has been measured with the Beijing Spectrometer. The measurement was made using 22.3 pb−1pb^{-1} of e+e−e^+e^- data collected at 4.03 GeV and 1.5 pb−1pb^{-1} of e+e−e^+e^- data collected at 4.14 GeV. Inclusive observed cross sections for the production of charged and neutral D mesons and momentum spectra are presented. Observed cross sections were radiatively corrected to obtain tree level cross sections. Measurements of the total hadronic cross section are obtained from the charmed meson cross section and an extrapolation of results from below the charm threshold.Comment: 11 pages, 13 figures. The top level tex file is paper.tex. It builds the paper from other tex files in this .tar and the .eps file
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