350 research outputs found

    Remarks on a Decrumpling Model of the Universe

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    It is argued that when the dimension of space is a constant integer the full set of Einstein's field equations has more information than the spatial components of Einstein's equation plus the energy conservation law. Applying the former approach to the decrumpling FRW cosmology recently proposed, it is shown that the spacetime singularity cannot be avoided and that turning points are absent. This result is in contrast to the decrumpling nonsingular spacetime model with turning points previously obtained using the latter approach.Comment: 8 pages, latex, no figure

    Baryogenesis from Long Cosmic Strings

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    Based on the mechanism of cusp production on long cosmic strings, the baryon asymmetry caused by cusp annihilation has been calculated. The result is compatible with observation and stronger than the results from loops.Comment: 7 pages, Latex, (ISTPM) IPM-94-05

    A model universe with variable dimension: Expansion as decrumpling

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    We propose a model universe, in which the dimension of the space is a continuous variable, which can take any real positive number. The dynamics leads to a model in which the universe has no singularity. The difference between our model and the standard Friedman-Robertson-Walker models become effective for times much before the presently accepted age of the universe.Comment: 12 pages, emTeX version 3.0, no figure

    Prediction of Natural Frequencies of Laminated Curved Panels Using Refined 2-D Theories in the Spectral Collocation Method

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    This paper presents a versatile and efficientmodeling and solution framework for free vibration analysis of composite laminated cylindrical and spherical panels modeled according to two-dimensional equivalent singlelayer and layerwise theories of variable order.Aunified formulation of the equations of motion is adopted which can be used for both thin and thick structures. The discretization procedure is based on the spectral collocation method and is presented in a compact matrix form which can be directly and easily implemented. The convergence and accuracy of the proposed approach is evaluated for panels having different boundary conditions, thickness and shallowness ratios, and lamination layups

    CBProf: Customisable Blockchain-as-a-Service Performance Profiler in Cloud Environments

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    Blockchain technologies, e.g., Hyperledger Fabric and Sawtooth, have been evolving rapidly during past years and enable potential decentralised innovations in a substantial amount of business applications, e.g. crowd journalism, car-sharing and energy trading. The development of decentralised business applications has to face challenges in selecting suitable blockchain technologies, customising network protocols among distributed peers, and optimising system performance to meet application requirements. Also, manually testing and comparing those different technologies are time-consuming. Therefore, an effective tool is needed for profiling the performance characteristics of blockchain services in different cloud environments. In this paper, we present the Customisable Blockchain-as-a-Service Performance Profiler (CBProf), a tool we developed for automating blockchain deployment and performance profiling in cloud environments. We also provide the implementation and functionality demonstration of this tool
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