5,197 research outputs found

    Multi-View Active Learning in the Non-Realizable Case

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    The sample complexity of active learning under the realizability assumption has been well-studied. The realizability assumption, however, rarely holds in practice. In this paper, we theoretically characterize the sample complexity of active learning in the non-realizable case under multi-view setting. We prove that, with unbounded Tsybakov noise, the sample complexity of multi-view active learning can be O~(log1ϵ)\widetilde{O}(\log\frac{1}{\epsilon}), contrasting to single-view setting where the polynomial improvement is the best possible achievement. We also prove that in general multi-view setting the sample complexity of active learning with unbounded Tsybakov noise is O~(1ϵ)\widetilde{O}(\frac{1}{\epsilon}), where the order of 1/ϵ1/\epsilon is independent of the parameter in Tsybakov noise, contrasting to previous polynomial bounds where the order of 1/ϵ1/\epsilon is related to the parameter in Tsybakov noise.Comment: 22 pages, 1 figur

    Analysis of the strong vertices of ΣcND\Sigma_cND^{*} and ΣbNB\Sigma_bNB^{*} in QCD sum rules

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    The strong coupling constant is an important parameter which can help us to understand the strong decay behaviors of baryons. In our previous work, we have analyzed strong vertices ΣcND\Sigma_{c}^{*}ND, ΣbNB\Sigma_{b}^{*}NB, ΣcND\Sigma_{c}ND, ΣbNB\Sigma_{b}NB in QCD sum rules. Following these work, we further analyze the strong vertices ΣcND\Sigma_{c}ND^{*} and ΣbNB\Sigma_{b}NB^{*} using the three-point QCD sum rules under Dirac structures q ⁣ ⁣ ⁣/p ⁣ ⁣ ⁣/γαq\!\!\!/p\!\!\!/\gamma_{\alpha} and q ⁣ ⁣ ⁣/p ⁣ ⁣ ⁣/pαq\!\!\!/p\!\!\!/p_{\alpha}. In this work, we first calculate strong form factors considering contributions of the perturbative part and the condensate terms qq\langle\overline{q}q\rangle, αsπGG\langle\frac{\alpha_{s}}{\pi}GG\rangle and qgsσGq\langle\overline{q}g_{s}\sigma Gq\rangle. Then, these form factors are used to fit into analytical functions. According to these functions, we finally determine the values of the strong coupling constants for these two vertices ΣcND\Sigma_{c}ND^{*} and ΣbNB\Sigma_{b}NB^{*}.Comment: arXiv admin note: text overlap with arXiv:1705.0322
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