6,209 research outputs found

    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

    CHINA'S INTERNATIONAL TOURISM UNDER ECONOMIC TRANSITION: NATIONAL TRENDS AND REGIONAL DISPARITIES

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    China's Tourism industry, especially international tourism, has expanded rapidly since its market-oriented economic reform started in 1978. There has been limited information regarding the trends and regional disparities. This paper examines the national trends of China's international tourism since 1982 and analyzes the changes in regional disparities since 1995. While the trend analysis suggests that China's international tourism is likely to keep growing at a significant rate, the analysis of regional disparities based on Gini coefficient indicates that the regional inequality in the number of international tourists and income has shown a downward trend since 1995. Findings from this study suggest that China's economic reform has stimulated the growth in international tourism and the international tourism has contributed to its economic growth and business development.Resource /Energy Economics and Policy,

    FedCIP: Federated Client Intellectual Property Protection with Traitor Tracking

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    Federated learning is an emerging privacy-preserving distributed machine learning that enables multiple parties to collaboratively learn a shared model while keeping each party's data private. However, federated learning faces two main problems: semi-honest server privacy inference attacks and malicious client-side model theft. To address privacy inference attacks, parameter-based encrypted federated learning secure aggregation can be used. To address model theft, a watermark-based intellectual property protection scheme can verify model ownership. Although watermark-based intellectual property protection schemes can help verify model ownership, they are not sufficient to address the issue of continuous model theft by uncaught malicious clients in federated learning. Existing IP protection schemes that have the ability to track traitors are also not compatible with federated learning security aggregation. Thus, in this paper, we propose a Federated Client-side Intellectual Property Protection (FedCIP), which is compatible with federated learning security aggregation and has the ability to track traitors. To the best of our knowledge, this is the first IP protection scheme in federated learning that is compatible with secure aggregation and tracking capabilities

    Covert Communication Based on the Poisoning Attack in Federated Learning

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    Covert communication has become an important area of research in computer security. It involves hiding specific information on a carrier for message transmission and is often used to transmit private data, military secrets, and even malware. In deep learning, many methods have been developed for hiding information in models to achieve covert communication. However, these methods are not applicable to federated learning, where model aggregation invalidates the exact information embedded in the model by the client. To address this problem, we propose a novel method for covert communication in federated learning based on the poisoning attack. Our approach achieves 100% accuracy in covert message transmission between two clients and is shown to be both stealthy and robust through extensive experiments. However, existing defense methods are limited in their effectiveness against our attack scheme, highlighting the urgent need for new protection methods to be developed. Our study emphasizes the necessity of research in covert communication and serves as a foundation for future research in federated learning attacks and defenses

    Changes in the milk metabolome of the Giant Panda (Ailuropoda melanoleuca) with time after birth: three phases in early lactation and progressive individual differences

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    Ursids (bears) in general, and giant pandas in particular, are highly altricial at birth. The components of bear milks and their changes with time may be uniquely adapted to nourish relatively immature neonates, protect them from pathogens, and support the maturation of neonatal digestive physiology. Serial milk samples collected from three giant pandas in early lactation were subjected to untargeted metabolite profiling and multivariate analysis. Changes in milk metabolites with time after birth were analysed by Principal Component Analysis, Hierarchical Cluster Analysis and further supported by Orthogonal Partial Least Square-Discriminant Analysis, revealing three phases of milk maturation: days 1–6 (Phase 1), days 7–20 (Phase 2), and beyond day 20 (Phase 3). While the compositions of Phase 1 milks were essentially indistinguishable among individuals, divergences emerged during the second week of lactation. OPLS regression analysis positioned against the growth rate of one cub tentatively inferred a correlation with changes in the abundance of a trisaccharide, isoglobotriose, previously observed to be a major oligosaccharide in ursid milks. Three artificial milk formulae used to feed giant panda cubs were also analysed, and were found to differ markedly in component content from natural panda milk. These findings have implications for the dependence of the ontogeny of all species of bears, and potentially other members of the Carnivora and beyond, on the complexity and sequential changes in maternal provision of micrometabolites in the immediate period after birth

    A note on the fractional Cauchy problems with nonlocal initial conditions

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    AbstractOf concern is the Cauchy problems for fractional integro-differential equations with nonlocal initial conditions. Using a new strategy in terms of the compactness of the semigroup generated by the operator in the linear part and approximating technique, a new existence theorem for mild solutions is established. An application to a fractional partial integro-differential equation with a nonlocal initial condition is also considered

    Oxonium 2-carb­oxy-3-(2-fur­yl)acrylate

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    In the title compound, H3O+·C8H5O5 −, neighbouring cations and anions are linked by O—H⋯O hydrogen bonds, forming a one-dimensional chain framework along [001]. The crystal structure is further stabilized by π–π inter­actions, with centroid–centroid distances of 3.734 (3) Å
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