6,505 research outputs found

    Deep Multi-instance Networks with Sparse Label Assignment for Whole Mammogram Classification

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    Mammogram classification is directly related to computer-aided diagnosis of breast cancer. Traditional methods rely on regions of interest (ROIs) which require great efforts to annotate. Inspired by the success of using deep convolutional features for natural image analysis and multi-instance learning (MIL) for labeling a set of instances/patches, we propose end-to-end trained deep multi-instance networks for mass classification based on whole mammogram without the aforementioned ROIs. We explore three different schemes to construct deep multi-instance networks for whole mammogram classification. Experimental results on the INbreast dataset demonstrate the robustness of proposed networks compared to previous work using segmentation and detection annotations.Comment: MICCAI 2017 Camera Read

    Magnetic structure of superconducting Eu(Fe0.82Co0.18)2As2 as revealed by single-crystal neutron diffraction

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    The magnetic structure of superconducting Eu(Fe0.82Co0.18)2As2 is unambiguously determined by single-crystal neutron diffraction. A long-range ferromagnetic order of the Eu2+ moments along the c-direction is revealed below the magnetic phase transition temperature Tc = 17 K. In addition, the antiferromagnetism of the Fe2+ moments still survives and the tetragonal-to-orthorhombic structural phase transition is also observed, although the transition temperatures of the Fe-spin density wave (SDW) order and the structural phase transition are significantly suppressed to Tn = 70 K and Ts = 90 K, respectively, compared to the parent compound EuFe2As2.We present the microscopic evidences for the coexistence of the Eu-ferromagnetism (FM) and the Fe-SDW in the superconducting crystal. The superconductivity (SC) competes with the Fe-SDW in Eu(Fe0.82Co0.18)2As2.Moreover, the comparison between Eu(Fe1-xCox)2As2 and Ba(Fe1-xCox)2As2 indicates a considerable influence of the rare-earth element Eu on the magnetism of the Fe sublattice.Comment: 7 pages, 7 figures, accepted for publication in Physical Review

    Approximate perturbed direct homotopy reduction method: infinite series reductions to two perturbed mKdV equations

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    An approximate perturbed direct homotopy reduction method is proposed and applied to two perturbed modified Korteweg-de Vries (mKdV) equations with fourth order dispersion and second order dissipation. The similarity reduction equations are derived to arbitrary orders. The method is valid not only for single soliton solution but also for the Painlev\'e II waves and periodic waves expressed by Jacobi elliptic functions for both fourth order dispersion and second order dissipation. The method is valid also for strong perturbations.Comment: 8 pages, 1 figur

    Effect of Grazing on Soil Fertility and Trace Elements of Temperate Desert Steppe in Northwestern China

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    Grazing is the dominant land use of temperate desert steppe in northwestern China. It is well established that the grazing process has impacts on plant production and biodiversity (Li 1997), but less is known about the effects of grazing chemical characteristics of grassland soils. Livestock feeding activities, especially the provision of supplementary sources, may influence pasture nutrient cycle, and in turn change the chemical composition of the grassland soil (Rong et al. 2001). Soil fertility may be affected by the type use and grazing intensities because these may cause alterations in soil physical and chemical properties as well as the soil biotia (Marzaioli et al. 2010; Caravacaa et al. 2002). The combination of these factors can reduce pasture productivity (Islam and Weil 2000; Sánchez-Marañón et al. 2002). Soil was the nutrient carrier to forage and livestock. Since changes in soil property will be reflected in both forage and livestock production directly or indirectly, it was important to study the effect of soil on grassland and grazing (Zhang et al. 2002), especially trace elements such as iron (Fe), manganese (Mn), copper (Cu) and zinc (Zn). In Alxa (Inner Mongolia), for example, Wu et al. (2008) reported a difference in the accumulation of these elements due to grassland type with a sequence of Fe\u3eMn\u3eZn\u3eCu in alpine meadow soil compared to a sequence of Fe \u3e Mn\u3eCu\u3eZn in mountainous steppe and desert steppe soils. The objective of this study is to investigate the effect of grazing on the concentrations of Fe, Mn, Cu and Zn in temperate desert steppe in Gansu Province

    Efficient synthesis of plate-like crystalline hydrated tungsten trioxide thin films with highly improved electrochromic performance

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    Cataloged from PDF version of article.Plate-like hydrated tungsten trioxide (3WO(3)center dot H(2)O) films were grown on a fluorine doped tin oxide (FTO) coated transparent conductive substrate via an efficient, facile and template-free hydrothermal method. The film exhibited a fast coloration/bleaching response (t(c90%) = 4.3 s and t(b90%) = 1.4 s) and a high coloration efficiency (112.7 cm(2) C(-1)), which were probably due to a large surface area

    Dense Packings of Superdisks and the Role of Symmetry

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    We construct the densest known two-dimensional packings of superdisks in the plane whose shapes are defined by |x^(2p) + y^(2p)| <= 1, which contains both convex-shaped particles (p > 0.5, with the circular-disk case p = 1) and concave-shaped particles (0 < p < 0.5). The packings of the convex cases with p 1 generated by a recently developed event-driven molecular dynamics (MD) simulation algorithm [Donev, Torquato and Stillinger, J. Comput. Phys. 202 (2005) 737] suggest exact constructions of the densest known packings. We find that the packing density (covering fraction of the particles) increases dramatically as the particle shape moves away from the "circular-disk" point (p = 1). In particular, we find that the maximal packing densities of superdisks for certain p 6 = 1 are achieved by one of the two families of Bravais lattice packings, which provides additional numerical evidence for Minkowski's conjecture concerning the critical determinant of the region occupied by a superdisk. Moreover, our analysis on the generated packings reveals that the broken rotational symmetry of superdisks influences the packing characteristics in a non-trivial way. We also propose an analytical method to construct dense packings of concave superdisks based on our observations of the structural properties of packings of convex superdisks.Comment: 15 pages, 8 figure

    The magnetoresistance and Hall effect in CeFeAsO: a high magnetic field study

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    The longitudinal electrical resistivity and the transverse Hall resistivity of CeFeAsO are simultaneously measured up to a magnetic field of 45T using the facilities of pulsed magnetic field at Los Alamos. Distinct behaviour is observed in both the magnetoresistance Rxx({\mu}0H) and the Hall resistance Rxy({\mu}0H) while crossing the structural phase transition at Ts \approx 150K. At temperatures above Ts, little magnetoresistance is observed and the Hall resistivity follows linear field dependence. Upon cooling down the system below Ts, large magnetoresistance develops and the Hall resistivity deviates from the linear field dependence. Furthermore, we found that the transition at Ts is extremely robust against the external magnetic field. We argue that the magnetic state in CeFeAsO is unlikely a conventional type of spin-density-wave (SDW).Comment: 4 pages, 3 figures SCES2010, To appear in J. Phys.: Conf. Ser. for SCES201
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