13,400 research outputs found

    Effective Field Theory For Nuclei: Confronting Fundamental Questions in Astrophysics

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    Fundamental issues involving nuclei in the celebrated solar neutrino problem are discussed in terms of an effective field theory adapted to nuclear few-body systems, with a focus on the proton fusion process and the hep process. Our strategy in addressing these questions is to combine chiral perturbation theory -- an effective field theory of QCD -- with an accurate nuclear physics approach to arrive at a more effective effective field theory that reveals and exploits a subtle role of the chiral-symmetry scale in short-distance effects encoded in short-range nuclear correlations. Our key argument is drawn from the close analogy of the principal weak matrix element figuring in the hep process to the suppressed matrix elements in the polarized neutron-proton capture at threshold currently being measured in the laboratories.Comment: 11 pages. Invited talk given by MR at the International Conference on Few-Body Problems, Taipei, Taiwan, 6-10 March 200

    Properties of Microlensing Central Perturbations by Planets in Binary Stellar Systems under the Strong Finite-Source Effect

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    We investigate high-magnification events caused by planets in wide binary stellar systems under the strong finite-source effect, where the planet orbits one of the companions. From this, we find that the pattern of central perturbations in triple lens systems commonly appears as a combination of individual characteristic patterns of planetary and binary lens systems in a certain range where the sizes of the caustics induced by a planet and a binary companion are comparable, and the range changes with the mass ratio of the planet to the planet-hosting star. Specially, we find that because of this central perturbation pattern, the characteristic feature of high-magnification events caused by the triple lens systems appears in the residual from the single-lensing light curve despite the strong finite-source effect, and it is discriminated from those of the planetary and binary lensing events and thus can be used for the identification of the existence of both planet and binary companion. This characteristic feature is a simultaneous appearance of two features. First, double negative-spike and single positive-spike features caused by the binary companion appear together in the residual, where the double negative spike occurs at both moments when the source enters and exits the caustic center and the single positive spike occurs at the moment just before the source enters into or just after the source exits from the caustic center. Second, the magnification excess before or after the single positive-spike feature is positive due to the planet, and the positive excess has a remarkable increasing or decreasing pattern depending on the source trajectory.Comment: 12 pages, 3 figures, accepted for publication in Ap

    A Comprehensive Survey of Image Augmentation Techniques for Deep Learning

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    Deep learning has been achieving decent performance in computer vision requiring a large volume of images, however, collecting images is expensive and difficult in many scenarios. To alleviate this issue, many image augmentation algorithms have been proposed as effective and efficient strategies. Understanding current algorithms is essential to find suitable methods or develop novel techniques for given tasks. In this paper, we perform a comprehensive survey on image augmentation for deep learning with a novel informative taxonomy. To get the basic idea why we need image augmentation, we introduce the challenges in computer vision tasks and vicinity distribution. Then, the algorithms are split into three categories; model-free, model-based, and optimizing policy-based. The model-free category employs image processing methods while the model-based method leverages trainable image generation models. In contrast, the optimizing policy-based approach aims to find the optimal operations or their combinations. Furthermore, we discuss the current trend of common applications with two more active topics, leveraging different ways to understand image augmentation, such as group and kernel theory, and deploying image augmentation for unsupervised learning. Based on the analysis, we believe that our survey gives a better understanding helpful to choose suitable methods or design novel algorithms for practical applications.Comment: Revisio

    Real-time data-driven and multi-scale model-guided system for bioproccess digital twin platform

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    Photo Quality Assessment based on a Focusing Map to Consider Shallow Depth of Field

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    Proliferation and advances in digital cameras encourage people to take many photos. However, the number of photos that people can access is increasing exponentially. Good quality photo selection is becoming burdensome. In this paper, we propose a novel method to evaluate photo quality considering DoF (Depth of Field) based on a focusing map. The focusing map is a form of saliency map classified into four levels based on the spatial distribution of Canny edges. We implemented it in a CUDA environment to improve the speed of focusing map generation. In order to evaluate our method, we tested our feature on the four classified 206 photos; then, we compare our method to a photo set manually classified by a user. The proposed measure efficiently assesses the photos with DoF. Especially, the expert group who used DSLR camera agreed that our photo assessment measure is useful

    The Solar Proton Burning Process Revisited In Chiral Perturbation Theory

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    The proton burning process p + p -> d + e(+) + \nu(e), important for the stellar evolution of main-sequence stars of mass equal to or less than that of the Sun, is computed in effective field theory using chiral perturbation expansion to the next-to-next-to leading chiral order. This represents a model-independent calculation consistent with low-energy effective theory of QCD comparable in accuracy to the radiative np capture at thermal energy previously calculated by first using very accurate two-nucleon wavefunctions backed up by an effective field theory technique with a finite cut-off. The result obtained thereby is found to support within theoretical uncertainties the previous calculation of the same process by Bahcall and his co-workers.Comment: 30 pages, 2 eps files, aaspp4.sty needed, slightly modified, to be published in Ap.
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