2,235 research outputs found

    Kinematic sensitivity of robot manipulators

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    Kinematic sensitivity vectors and matrices for open-loop, n degrees-of-freedom manipulators are derived. First-order sensitivity vectors are defined as partial derivatives of the manipulator's position and orientation with respect to its geometrical parameters. The four-parameter kinematic model is considered, as well as the five-parameter model in case of nominally parallel joint axes. Sensitivity vectors are expressed in terms of coordinate axes of manipulator frames. Second-order sensitivity vectors, the partial derivatives of first-order sensitivity vectors, are also considered. It is shown that second-order sensitivity vectors can be expressed as vector products of the first-order sensitivity vectors

    Elastic and Diffractive Scattering after AdS/CFT

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    At high energies, elastic hadronic cross sections are believed to be dominated by vacuum exchange. In leading order of the leading 1/Nc1/N_c expansion this exchange process has been identified as the BFKL {\em Pomeron} or its strong AdS dual the closed string graviton \cite{Brower:2006ea}. However difference of particle anti-particle cross sections are given by a so-called {\em Odderon} carrying C = -1 quantum numbers identified in weak coupling with odd numbers of exchanged gluons. Here we show that the dual description associates this with the Neveu-Schwartz (BμνB_{\mu\nu}) sector of closed string theory. We also discuss the extension of the strong coupling treatment to central diffractive Higgs production at LHC.Comment: 7 pages, 3 figures; presented at International Conference on Elastic and Diffractive Scattering, EDS'09, CERN, July 3, 200

    Saturation and Confinement: Analyticity, Unitarity and AdS/CFT Correspondence

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    In 1/Nc1/N_c expansion, analyticity and crossing lead to crossing even and odd (C=±1C=\pm 1) vacuum exchanges at high-energy, the {\em Pomeron} and the {\em Odderon}. We discuss how, using {\em String/Gauge duality}, these can be identified with a reggeized {\em Graviton} and the anti-symmetric {\em Kalb-Ramond fields} in AdSAdS background. With confinement, these Regge singularities interpolate with glueball states. We also discuss unitarization based on eikonal sum in AdSAdS.Comment: more references added. presented at ISMD 2008, 15-20 Sept. 200
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