16,494 research outputs found

    Geometry and General Relativity in the Groupoid Model with a Finite Structure Group

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    In a series of papers we proposed a model unifying general relativity and quantum mechanics. The idea was to deduce both general relativity and quantum mechanics from a noncommutative algebra AΓ{\cal A}_{\Gamma} defined on a transformation groupoid Γ\Gamma determined by the action of the Lorentz group on the frame bundle (E,πM,M)(E, \pi_M, M) over space-time MM. In the present work, we construct a simplified version of the gravitational sector of this model in which the Lorentz group is replaced by a finite group GG and the frame bundle is trivial E=M×GE=M\times G. The model is fully computable. We define the Einstein-Hilbert action, with the help of which we derive the generalized vacuum Einstein equations. When the equations are projected to space-time (giving the "general relativistic limit"), the extra terms that appear due to our generalization can be interpreted as "matter terms", as in Kaluza-Klein-type models. To illustrate this effect we further simplify the metric matrix to a block diagonal form, compute for it the generalized Einstein equations and find two of their "Friedmann-like" solutions for the special case when G=Z2G =\mathbb{Z}_2. One of them gives the flat Minkowski space-time (which, however, is not static), another, a hyperbolic, linearly expanding universe.Comment: 32 page

    Impact of a process improvement program in a production software environment: Are we any better?

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    For the past 15 years, Computer Sciences Corporation (CSC) has participated in a process improvement program as a member of the Software Engineering Laboratory (SEL), which is sponsored by GSFC. The benefits CSC has derived from involvement in this program are analyzed. In the environment studied, it shows that improvements were indeed achieved, as evidenced by a decrease in error rates and costs over a period in which both the size and the complexity of the developed systems increased substantially. The principles and mechanics of the process improvement program, the lessons CSC has learned, and how CSC has capitalized on these lessons are also discussed

    Technology transfer - A selected bibliography

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    Selected bibliography on technology transfe

    P-wave meson properties with Wilson quarks

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    We describe two calculations involving P-wave mesons made of Wilson quarks: the strong coupling constant αs\alpha_s in the presence of two flavors of light dynamical fermions and the mass and decay constant of the a1a_1 meson.Comment: Poster presented at Lattice '94, September 27--October 1, 1994, Bielefeld, Germany (no changes to manuscript, but correction of Authors list above

    Application of serious games to sport, health and exercise

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    Use of interactive entertainment has been exponentially expanded since the last decade. Throughout this 10+ year evolution there has been a concern about turning entertainment properties into serious applications, a.k.a "Serious Games". In this article we present two set of Serious Game applications, an Environment Visualising game which focuses solely on applying serious games to elite Olympic sport and another set of serious games that incorporate an in house developed proprietary input system that can detect most of the human movements which focuses on applying serious games to health and exercise
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