3,173 research outputs found

    Commissioning of the ATLAS Experiment

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    The status of the commissioning of the ATLAS experiment as of May 2008 is presented. The sub-detector integration in recent milestone weeks is described. Cosmic commissioning in milestone week M6 included simultaneous data-taking and combined track analysis of the muon detector and inner detector, as well as combined analysis of muon detector and muon trigger. The calorimeters have achieved near-full operation, and are integrated with the calorimeter trigger. The high-level-trigger infrastructure is being installed and algorithms tested in technical runs

    On the Newtonian Limit of the Weyl Tensor

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    In this note we wish to complement some recent work in the cosmological literature concerning the Weyl conformal curvature tensor and its parts. In particular, we shall give a clear-cut definition of the Newtonian limits of electric and magnetic parts of the Weyl tensor. We also discuss that only a subset of the relativistic equations is needed to obtain a closed system of equations in the Newtonian limit.Comment: 6 pages. Dedicated to the memory of Juergen Ehlers. To appear in the upcoming Special Issue of "General Relativity and Gravitation

    The Use of ITIL for Process Optimisation in the IT Service Centre of Harz University, exemplified in the Release Management Process

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    This paper details the use of the IT Infrastructure Library Framework (ITIL) for optimising process workflows in the IT Service Centre of Harz University in Wernigerode, Germany, exemplified by the Release Management Process. It is described, how, during the course of a special ITIL project, the As-Is-Status of the various original processes was documented as part of the process life cycle and then transformed in the To-Be-Status, according to the ITIL Best Practice Framework. It is also shown, how the ITIL framework fits into the four-layered-process model, that could be derived from interviews with the universities IT support staff, and how the various modified processes interconnect with each other to form a value chain. The paper highlights the final results of the project and gives an outlook on the future use of ITIL as a business modelling tool in the IT Service Centre of Harz University. It is currently being considered, whether the process model developed during the project could be used as a reference model for other university IT centres.Comment: 7 pages, 7 figure

    The multicomponent structure of bulges

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    The morphology of disk galaxies is usually described by two major components, the centrally concentrated spheroidal component, called the bulge, and an oblate disk. The ratio of there contribution to the total luminosity - the bulge-to-disk ratio - is one of the parameters characterizing the Hubble sequence. Following de Vaucouleurs (1948), for most galaxies the radial distribution of the outer spheroid is fairly well described by the r exp 1/4 law I(r)=I(sub 0) exp(-(alpha)r), whereas the radial luminosity distribution of the disk follows an exponential law: I(r)=I(sub 0) exp(-alpha(r exp 1/4)) (Freeman 1970), with r the radial distance from the center. I(sub 0) and alpha are characteristic constants for each individual galaxy. Parameters for the structural properties of these components give important constraints for models of the formation and evolution of galaxies. Therefore we have tried to decompose disk and bulge components from high S/N CCD observations of a sample of edge-on disk galaxies. A common procedure for the decomposition is to model one component in a region where it dominates and subtract it from the combined light distribution. This technique was successfully carried out e.g. by van der Kruit & Earl (1981, 1982) and Wakamatsu & Hamabe (1984, 1989). Here we present two more examples of bulge-dominated edge-on SO galaxies, namely ESO 506-G33 and NGC 7123, which show an additional small and concentrated central component besides disk and 'bulge'

    Exact Fidelity and Full Fidelity Statistics in Regular and Chaotic Surroundings

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    For a prepared state exact expressions for the time dependent mean fidelity as well as for the mean inverse paricipation ratio are obtained analytically. The distribution function of fidelity in the long time limit and of inverse participation ratio are studied numerically and analytically. Surprising features like fidelity revival and enhanced non--ergodicity are observed. The role of the coupling coefficients and of complexity of background is studied as well.Comment: 4 pages 3 figure
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