15,805 research outputs found

    Fourth Amendment Implications of Warrantless Aerial Surveillance

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    Aircraft Conceptual Structural Design Using the AMMIT Structural Analysis Tool

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    Aircraft conceptual structural design is the process of developing and refining an idea for an aircraft into a feasible structural design. The process typically involves multiple evaluations of a single configuration and can require designers to examine thousands of concepts. Standard approaches to conducting structural analyses in this phase are either based on the use of historical or empirical data or often require significant expertise in structural analysis to perform these rapid assessments. The AMMIT structural analysis tool includes structural line models and handbook methods wrapped in a simple to use interface that can enable rapid, physics-based structural designs without requiring extensive structural expertise. The objectives of the present paper are to introduce AMMIT, describe the methods used in AMMIT, and present the results of the validation effort. Validation of the AMMIT methodology was performed on nine aircraft to determine the accuracy of the methods, highlight features of AMMIT, and guide future development of the methodology. Results of the validation effort indicated that AMMIT provides a prediction of primary structural weight for each aircraft with an acceptable level of error during the preliminary design phase with a minimal expenditure of computational resources

    Analysis of the BATSE Continuous MER data

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    The CGRO/BATSE database includes many types of data such as the 16-channel continuous background or medium energy resolution burst data (CONT and MER data types). We have calculated some four hundred burst's medium energy resolution spectra and Principal Component Analysis has been applied. We found five components can describe GRBs' spectra.Comment: 4 pages, 2 figures, accepted in Nuovo Ciment

    Self-consistent pedestal prediction for JET-ILW in preparation of the DT campaign

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    The self-consistent core-pedestal prediction model of a combination of EPED1 type pedestal prediction and a simple stiff core transport model is able to predict Type I ELMy (edge localized mode) pedestals of a large JET-ILW (ITER-like wall) database at the similar accuracy as is obtained when the experimental global plasma beta is used as input. The neutral penetration model [R. J. Groebner et al., Phys. Plasmas 9, 2134 (2002)] with corrections that take into account variations due to gas fueling and plasma triangularity is able to predict the pedestal density with an average error of 15%. The prediction of the pedestal pressure in hydrogen plasma that has higher core heat diffusivity compared to a deuterium plasma with similar heating and fueling agrees with the experiment when the isotope effect on the stability, the increased diffusivity, and outward radial shift of the pedestal are included in the prediction. However, the neutral penetration model that successfully predicts the deuterium pedestal densities fails to predict the isotope effect on the pedestal density in hydrogen plasmas

    Analysis of a space--time hybridizable discontinuous Galerkin method for the advection--diffusion problem on time-dependent domains

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    This paper presents the first analysis of a space--time hybridizable discontinuous Galerkin method for the advection--diffusion problem on time-dependent domains. The analysis is based on non-standard local trace and inverse inequalities that are anisotropic in the spatial and time steps. We prove well-posedness of the discrete problem and provide a priori error estimates in a mesh-dependent norm. Convergence theory is validated by a numerical example solving the advection--diffusion problem on a time-dependent domain for approximations of various polynomial degree

    Multiphoton Coincidence Spectroscopy

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    We extend the analysis of photon coincidence spectroscopy beyond bichromatic excitation and two-photon coincidence detection to include multichromatic excitation and multiphoton coincidence detection. Trichromatic excitation and three-photon coincidence spectroscopy are studied in detail, and we identify an observable signature of a triple resonance in an atom-cavity system.Comment: 6 page, REVTeXs, 6 Postscript figures. The abstract appeared in the Proceedings of ACOLS9
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