255,509 research outputs found

    XML data integrity based on concatenated hash function

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    Data integrity is the fundamental for data authentication. A major problem for XML data authentication is that signed XML data can be copied to another document but still keep signature valid. This is caused by XML data integrity protecting. Through investigation, the paper discovered that besides data content integrity, XML data integrity should also protect element location information, and context referential integrity under fine-grained security situation. The aim of this paper is to propose a model for XML data integrity considering XML data features. The paper presents an XML data integrity model named as CSR (content integrity, structure integrity, context referential integrity) based on a concatenated hash function. XML data content integrity is ensured using an iterative hash process, structure integrity is protected by hashing an absolute path string from root node, and context referential integrity is ensured by protecting context-related elements. Presented XML data integrity model can satisfy integrity requirements under situation of fine-grained security, and compatible with XML signature. Through evaluation, the integrity model presented has a higher efficiency on digest value-generation than the Merkle hash tree-based integrity model for XML data

    Confinement of matter fields in compact (2+1)-dimensional QED theory of high-TcT_{c} superconductors

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    We study confinement of matter fields in the effective compact (2+1)-dimensional QED theory of high-TcT_{c} superconductors. It is shown that the monopole configurations do not affect the propagator of gauge potential aÎĽa_{\mu}. Based on this result, we found that: chiral symmetry breaking and confinement take place simultaneously in the antiferromagnetic state; neither monopole effect nor Anderson-Higgs mechanism can cause confinement in the d-wave superconducting state.Comment: 5 pages, no figure

    A Lattice Study of the Glueball Spectrum

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    Glueball spectrum is studied using an improved gluonic action on asymmetric lattices in the pure SU(3) gauge theory. The smallest spatial lattice spacing is about 0.08fm0.08fm which makes the extrapolation to the continuum limit more reliable. In particular, attention is paid to the scalar glueball mass which is known to have problems in the extrapolation. Converting our lattice results to physical units using the scale set by the static quark potential, we obtain the following results for the glueball masses: MG(0++)=1730(90)MeVM_G(0^{++})=1730(90)MeV for the scalar glueball mass and MG(2++)=2400(95)MeVM_G(2^{++})=2400(95)MeV for the tensor glueball.Comment: 10 pages, 2 figures,typos correcte

    Enhanced visibility of graphene: effect of one-dimensional photonic crystal

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    We investigate theoretically the light reflectance of a graphene layer prepared on the top of one-dimensional Si/SiO2 photonic crystal (1DPC). It is shown that the visibility of the graphene layers is enhanced greatly when 1DPC is added, and the visibility can be tuned by changing the incident angle and light wavelengths. This phenomenon is caused by the absorption of the graphene layer and the enhanced reflectance of the 1DPC.Comment: 4 pages, 4 figures. published, ApplPhysLett_91_18190

    Identification of photons in double beta-decay experiments using segmented germanium detectors - studies with a GERDA Phase II prototype detector

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    The sensitivity of experiments searching for neutrinoless double beta-decay of germanium was so far limited by the background induced by external gamma-radiation. Segmented germanium detectors can be used to identify photons and thus reduce this background component. The GERmanium Detector Array, GERDA, will use highly segmented germanium detectors in its second phase. The identification of photonic events is investigated using a prototype detector. The results are compared with Monte Carlo data.Comment: 20 pages, 7 figures, to be submitted to NIM-
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