3,125 research outputs found

    Surface and Edge States in Topological Semi-metals

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    We study the topologically non-trivial semi-metals by means of the 6-band Kane model. Existence of surface states is explicitly demonstrated by calculating the LDOS on the material surface. In the strain free condition, surface states are divided into two parts in the energy spectrum, one part is in the direct gap, the other part including the crossing point of surface state Dirac cone is submerged in the valence band. We also show how uni-axial strain induces an insulating band gap and raises the crossing point from the valence band into the band gap, making the system a true topological insulator. We predict existence of helical edge states and spin Hall effect in the thin film topological semi-metals, which could be tested with future experiment. Disorder is found to significantly enhance the spin Hall effect in the valence band of the thin films

    Effect of Aggregate Gradation with Fuller Distribution on Properties of Sulfoaluminate Cement Concrete

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    Aggregate, the main ingredient of concrete, has a great effect on mechanical property and durability of concrete. Sulfoaluminate cement has lots of special properties such as high early-age compressive strength, fast hydration and setting rate, and hydration with slight swelling. But effect of aggregate gradation with Fuller distribution on properties of sulfoaluminate cement concrete was seldom studied. Hence, in this paper, experimental investigations on mechanical property and durability of sulfoaluminate cement concrete with aggregate gradations according to Fuller distribution were presented. Fuller distribution of aggregates was beneficial to the close packing of aggregates, and the packing density was changed by adjusting the aggregate gradations. Compressive strength, water impermeability, and resistance capability to sulfate attack of SACC have the same trend of concrete with fine aggregates of Fuller distribution gradation \u3c concrete with fine aggregates of Fuller distribution gradation \u3c concrete with fine aggregates of Fuller distribution gradation. The relationship between packing density of aggregate and water penetration depth obeyed the second-order polynomial y = 0.002x2 – 6.8638x + 5862.3 and had a notable correlation R2 = 0.9799. The sulfoaluminate cement concrete with total aggregate gradation with Fuller distribution for h = 0.50 had the best resistance capability to sulfate attack. It was a second-order polynomial relationship between packing density of aggregates and water penetration depth of y = 0.002x2 – 6.8638x + 5862.3 with R2 = 0.9799, which indicated notable correlation. The fitting formula between packing density of aggregates and sulfate resistance coefficient of SACC was y = 0.0.0005x + 0.3704 with R2 = 0.9585

    完全準同型暗号によるセキュアクラウドコンピューティング

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    筑波大学 (University of Tsukuba)201

    完全準同型暗号によるセキュアクラウドコンピューティング

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    筑波大学 (University of Tsukuba)201

    Morroniside ameliorates lipopolysaccharide-induced inflammatory damage in iris pigment epithelial cells through inhibition of TLR4/JAK2/STAT3 pathway

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    AIM: To investigate the effect of morroniside (Mor) on lipopolysaccharide (LPS)-treated iris pigment epithelial cells (IPE). METHODS: IPE cells were induced by LPS and treated with Mor. Cell proliferation was detected by cell counting kit (CCK) -8, apoptosis was detected by flow cytometry, the levels of tumor necrosis factor-α (TNF-α), interleukin (IL)-6, and IL-8 were measured by enzyme-linked immunosorbent assay (ELISA) kits, and the protein expression of TLR4, JAK2, p-JAK2, STAT3, and p-STAT3 was analyzed by Western blotting. In addition, overexpression of TLR4 and Mor treatment of LPS-stimulated IPE cells were also tested for the above indices. RESULTS: Mor effectively promoted the proliferation and inhibited the apoptosis of LPS-treated IPE cells. In addition, Mor significantly reduced the levels of TNF-α, IL-6, and IL-8 and significantly inhibited the expression of TLR4, p-JAK2, and p-STAT3 in LPS-treated IPE cells. The effect of Mor on LPS-treated IPE cells was markedly attenuated after overexpression of TLR4. CONCLUSION: These findings suggest that Mor may ameliorate LPS-induced inflammatory damage and apoptosis in IPE through inhibition of TLR4/JAK2/STAT3 pathway

    Using Fully Homomorphic Encryption for Statistical Analysis of Categorical, Ordinal and Numerical Data

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    In recent years, there has been a growing trend towards outsourcing of computational tasks with the development of cloud services. The Gentry’s pioneering work of fully homomorphic encryption (FHE) and successive works have opened a new vista for secure and practical cloud computing. In this paper, we consider performing statistical analysis on encrypted data. To improve the efficiency of the computations, we take advantage of the batched computation based on the Chinese-Remainder-Theorem. We propose two building blocks that work with FHE: a novel batch greater-than primitive, and matrix primitive for encrypted matrices. With these building blocks, we construct secure procedures and protocols for different types of statistics including the histogram (count), contingency table (with cell suppression) for categorical data; k-percentile for ordinal data; and principal component analysis and linear regression for numerical data. To demonstrate the effectiveness of our methods, we ran experiments in five real datasets. For instance, we can compute a contingency table with more than 50 cells from 4000 of data in just 5 minutes, and we can train a linear regression model with more than 40k of data and dimension as high as 6 within 15 minutes. We show that the FHE is not as slow as commonly believed and it becomes feasible to perform a broad range of statistical analysis on thousands of encrypted data
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