42,212 research outputs found

    Human motion modeling and simulation by anatomical approach

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    To instantly generate desired infinite realistic human motion is still a great challenge in virtual human simulation. In this paper, the novel emotion effected motion classification and anatomical motion classification are presented, as well as motion capture and parameterization methods. The framework for a novel anatomical approach to model human motion in a HTR (Hierarchical Translations and Rotations) file format is also described. This novel anatomical approach in human motion modelling has the potential to generate desired infinite human motion from a compact motion database. An architecture for the real-time generation of new motions is also propose

    Electronic structure of YbB6_{6}: Is it a Topological Insulator or not?

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    To resolve the controversial issue of the topological nature of the electronic structure of YbB6_{6}, we have made a combined study using density functional theory (DFT) and angle resolved photoemission spectroscopy (ARPES). Accurate determination of the low energy band topology in DFT requires the use of modified Becke-Johnson exchange potential incorporating the spin-orbit coupling and the on-site Coulomb interaction UU of Yb 4f4f electrons as large as 7 eV. We have double-checked the DFT result with the more precise GW band calculation. ARPES is done with the non-polar (110) surface termination to avoid band bending and quantum well confinement that have confused ARPES spectra taken on the polar (001) surface termination. Thereby we show definitively that YbB6_{6} has a topologically trivial B 2pp-Yb 5dd semiconductor band gap, and hence is a non-Kondo non-topological insulator (TI). In agreement with theory, ARPES shows pure divalency for Yb and a pp-dd band gap of 0.3 eV, which clearly rules out both of the previous scenarios of ff-dd band inversion Kondo TI and pp-dd band inversion non-Kondo TI. We have also examined the pressure-dependent electronic structure of YbB6_{6}, and found that the high pressure phase is not a Kondo TI but a \emph{p}-\emph{d} overlap semimetal.Comment: The main text is 6 pages with 4 figures, and the supplementary information contains 6 figures. 11 pages, 10 figures in total To be appeared in Phys. Rev. Lett. (Online publication is around March 16 if no delays.

    Gauge/String-Gravity Duality and Froissart Bound

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    The gauge/string-gravity duality correspondence opened renewed hope and possibility to address some of the fundamental and non-perturbative QCD problems in particle physics, such as hadron spectrum and Regge behavior of the scattering amplitude at high energies. One of the most fundamental and long-standing problem is the high energy behavior of total cross-sections. According to a series of exhaustive tests by the COMPETE group, (1). total cross-sections have a universal Heisenberg behavior in energy corresponding to the maximal energy behavior allowed by the Froissart bound, i.e., A+Bln2(s/s0)A + B ln^2 (s/s_0) with B∼0.32mbB \sim 0.32 mb and s0∼34.41GeV2s_0 \sim 34.41 GeV^2 for all reactions, and (2). the factorization relation among σpp,even,σγp,andσγγ\sigma_{pp, even}, \sigma_{\gamma p}, and \sigma_{\gamma \gamma} is well satisfied by experiments. I discuss the recent interesting application of the gauge/string-gravity duality of AdS/CFTAdS/CFT correspondence with a deformed background metric so as to break the conformal symmetry that can lead to the Heisenberg behavior of rising total cross-sections, and present some preliminary results on the high energy QCD from Planckian scattering in AdSAdS and black-hole production.Comment: 10 pages, Presented to the Coral Gables Conference 2003, Launching of BelleE\'poque in High Energy Physics and Cosmology, 17 - 21 December 2003, Fort Lauderdale, Florid

    Defect Motion and Lattice Pinning Barrier in Josephson-Junction Ladders

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    We study motion of domain wall defects in a fully frustrated Josephson-unction ladder system, driven by small applied currents. For small system sizes, the energy barrier E_B to the defect motion is computed analytically via symmetry and topological considerations. More generally, we perform numerical simulations directly on the equations of motion, based on the resistively-shunted junction model, to study the dynamics of defects, varying the system size. Coherent motion of domain walls is observed for large system sizes. In the thermodynamical limit, we find E_B=0.1827 in units of the Josephson coupling energy.Comment: 7 pages, and to apear in Phys. Rev.

    High Speed Forming Press Using Electromagnetic Pulse Force

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    In this paper, the finite element analysis for the design of a high speed forming press using electromagnetic pulse force has been performed. The punch of the press has been fixed on a aluminium plate, which is driven by the electromagnetic pulse force. The force is the repulsive force between aluminium plate and the coil. The coil has been supplied with a high voltage AC current impulse from the capacitors and then the magnetized aluminium plate has been forced to move upward with high speed. For the analysis of the pressing, the coupled analysis of electromagnetic field and rigid-body dynamic of the aluminium plate has been performed with a commercial FE-software, ANSYS and the rigid-body dynamics theory
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