829 research outputs found

    Cosmic constraint on the unified model of dark sectors with or without a cosmic string fluid in the varying gravitational constant theory

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    Observations indicate that most of the universal matter are invisible and the gravitational constant G(t)G(t) maybe depends on the time. A theory of the variational GG (VG) is explored in this paper, with naturally producing the useful dark components in universe. We utilize the observational data: lookback time data, model-independent gamma ray bursts, growth function of matter linear perturbations, type Ia supernovae data with systematic errors, CMB and BAO to restrict the unified model (UM) of dark components in VG theory. Using the best-fit values of parameters with the covariance matrix, constraints on the variation of GG are (GG0)z=3.5≃1.0015βˆ’0.0075+0.0071(\frac{G}{G_{0}})_{z=3.5}\simeq 1.0015^{+0.0071}_{-0.0075} and (GΛ™G)todayβ‰ƒβˆ’0.7252βˆ’2.3645+2.3645Γ—10βˆ’13yrβˆ’1(\frac{\dot{G}}{G})_{today}\simeq -0.7252^{+2.3645}_{-2.3645}\times 10^{-13} yr^{-1}, the small uncertainties around constants. Limit on the equation of state of dark matter is w0dm=0.0072βˆ’0.0170+0.0170w_{0dm}=0.0072^{+0.0170}_{-0.0170} with assuming w0de=βˆ’1w_{0de}=-1 in unified model, and dark energy is w0de=βˆ’0.9986βˆ’0.0011+0.0011w_{0de}=-0.9986^{+0.0011}_{-0.0011} with assuming w0dm=0w_{0dm}=0 at prior. Restriction on UM parameters are Bs=0.7442βˆ’0.0132βˆ’0.0292+0.0137+0.0262B_{s}=0.7442^{+0.0137+0.0262}_{-0.0132-0.0292} and Ξ±=0.0002βˆ’0.0209βˆ’0.0422+0.0206+0.0441\alpha=0.0002^{+0.0206+0.0441}_{-0.0209-0.0422} with 1Οƒ1\sigma and 2Οƒ2\sigma confidence level. In addition, the effect of a cosmic string fluid on unified model in VG theory are investigated. In this case it is found that the Ξ›\LambdaCDM (Ξ©s=0\Omega_{s}=0, Ξ²=0\beta=0 and Ξ±=0\alpha=0) is included in this VG-UM model at 1Οƒ1\sigma confidence level, and the larger errors are given: Ξ©s=βˆ’0.0106βˆ’0.0305βˆ’0.0509+0.0312+0.0582\Omega_{s}=-0.0106^{+0.0312+0.0582}_{-0.0305-0.0509} (dimensionless energy density of cosmic string), (GG0)z=3.5≃1.0008βˆ’0.0584+0.0620(\frac{G}{G_{0}})_{z=3.5}\simeq 1.0008^{+0.0620}_{-0.0584} and (GΛ™G)todayβ‰ƒβˆ’0.3496βˆ’26.3135+26.3135Γ—10βˆ’13yrβˆ’1(\frac{\dot{G}}{G})_{today}\simeq -0.3496^{+26.3135}_{-26.3135}\times 10^{-13}yr^{-1}.Comment: 17 pages,4 figure

    Learning to Predict Charges for Criminal Cases with Legal Basis

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    The charge prediction task is to determine appropriate charges for a given case, which is helpful for legal assistant systems where the user input is fact description. We argue that relevant law articles play an important role in this task, and therefore propose an attention-based neural network method to jointly model the charge prediction task and the relevant article extraction task in a unified framework. The experimental results show that, besides providing legal basis, the relevant articles can also clearly improve the charge prediction results, and our full model can effectively predict appropriate charges for cases with different expression styles.Comment: 10 pages, accepted by EMNLP 201

    Connecting Software Metrics across Versions to Predict Defects

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    Accurate software defect prediction could help software practitioners allocate test resources to defect-prone modules effectively and efficiently. In the last decades, much effort has been devoted to build accurate defect prediction models, including developing quality defect predictors and modeling techniques. However, current widely used defect predictors such as code metrics and process metrics could not well describe how software modules change over the project evolution, which we believe is important for defect prediction. In order to deal with this problem, in this paper, we propose to use the Historical Version Sequence of Metrics (HVSM) in continuous software versions as defect predictors. Furthermore, we leverage Recurrent Neural Network (RNN), a popular modeling technique, to take HVSM as the input to build software prediction models. The experimental results show that, in most cases, the proposed HVSM-based RNN model has a significantly better effort-aware ranking effectiveness than the commonly used baseline models
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