11,652 research outputs found

    Composite load spectra for select space propulsion structural components

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    This report summarizes the development for: (1) correlation fields; (2) applications to liquid oxygen post; (3) models for pressure fluctuatios and vibration loads fluctuations; (4) additions to expert systems; and (5) scaling criteria. Implementation to computer code is also described. Demonstration sample cases are included with additional applications to engine duct and pipe bend

    Quasilocal Center-of-Mass for Teleparallel Gravity

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    Asymptotically flat gravitating systems have 10 conserved quantities, which lack proper local densities. It has been hoped that the teleparallel equivalent of Einstein's GR (TEGR, aka GR∣∣{}_{||}) could solve this gravitational energy-momentum localization problem. Meanwhile a new idea: quasilocal quantities, has come into favor. The earlier quasilocal investigations focused on energy-momentum. Recently we considered quasilocal angular momentum for the teleparallel theory and found that the popular expression (unlike our ``covariant-symplectic'' one) gives the correct result only in a certain frame. We now report that the center-of-mass moment, which has largely been neglected, gives an even stronger requirement. We found (independent of the frame gauge) that our ``covariant symplectic'' Hamiltonian-boundary-term quasilocal expression succeeds for all the quasilocal quantities, while the usual expression cannot give the desired center-of-mass moment. We also conclude, contrary to hopes, that the teleparallel formulation appears to have no advantage over GR with regard to localization.Comment: 12 pages, to appear in the proceedings of the 10th Marcel Grossman meeting (Rio de Janeiro, 2003

    Global Diffusion of the Internet VIII: Maximum Resolution Dichotomy for Global Diffusion of the Internet

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    The Global Diffusion of the Internet (GDI) framework was used to study the progress in the adoption of the Internet in close to 30 countries since 1997. A new methodology in data mining is presented to extend the use of Kiviat diagrams to visualize the framework cast in a supply-demand dichotomy. A maximum resolution topology is derived as an additional tool for exploratory data analysis of such GDI dichotomies
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