18,095 research outputs found

    Optimal control and convex programming

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    Computational scheme for optimal control problem based on convex programming metho

    Existence and uniqueness of equilibrium points for concave n-person games

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    Existence and uniqueness of equilibrium points for concave n-person games - dynamic model for nonequilibrium situation

    A study of RSI under combined stresses

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    The behavior of typical rigidized surface insulation material (RSI) under combined loading states was investigated. In particular, the thermal stress states induced during reentry of the space shuttle were of prime concern. A typical RSI tile was analyzed for reentry thermal stresses under computed thermal gradients for a model of the RSI material. The results of the thermal stress analyses were then used to aid in defining typical combined stress states for the failure analysis of RSI

    Computation of the pseudinverse of a matrix of unknown rank

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    Least squares solution to linear system and computation of pseudoinverse by matrix of unknown ran

    The estimation of the propagation delay through the troposphere from microwave radiometer data

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    The uncertainity in propagation delay estimates is due primarily to tropospheric water, the total amount and vertical distribution of which is variable. Because water vapor both delays and attenuates microwave signals, the propagation delay, or wet path length, can be estimated from the microwave brightness temperature near the 22.235 GHz transition of water vapor. The data from a total of 240 radiosonde launches taken simultaneously were analyzed. Estimates of brightness temperature at 19 and 22 GHz and wet path length were made from these data. The wet path length in the zenith direction could be estimated from the surface water vapor density to an accuracy of 5 cm for the summer data and 2 cm for winter data. Using the brightness temperatures, the wet path could be estimated to an accuracy of 0.3 cm. Two dual frequency radiometers were refurbished in order to test these techniques. These radiometers were capable of measuring the difference in the brightness temperature at 30 deg elevation angle and at the zenith to an accuracy of about 1 K. In August 1975, 45 radiosondes were launched over an 11 day period. Brightness temperature measurements were made simultaneously at 19 and 22 GHz with the radiometers. The rms error for the estimation of wet path length from surface meteorological parameters was 3.2 cm, and from the radiometer brightness temperatures, 1.5 cm

    Why do firms go public? evidence from the banking industry

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    The lack of data on private firms has made it difficult to empirically examine theories of why firms go public. However, both public and private banks must disclose financial information to regulators. We exploit this requirement to explore the going-public decision. Our results indicate that banks that convert to public ownership are more likely to become targets than control banks that remain private. Banks that go public are also more likely to become acquirers than control banks. IPO banks grow faster than control banks after going public, although there is some evidence that their performance deteriorates.Financial institutions

    An investigation of the compressive strength of PRD-49-3/Epoxy composites

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    The development of unidirectional fiber composite materials is discussed. The mechanical and physical properties of the materials are described. Emphasis is placed in analyzing the compressive behavior of composite materials and developing methods for increasing compressive strength. The test program for evaluating the various procedures for improving compressive strength are reported

    Collision of High Frequency Plane Gravitational and Electromagnetic Waves

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    We study the head-on collision of linearly polarized, high frequency plane gravitational waves and their electromagnetic counterparts in the Einstein-Maxwell theory. The post-collision space-times are obtained by solving the vacuum Einstein-Maxwell field equations in the geometrical optics approximation. The head-on collisions of all possible pairs of these systems of waves is described and the results are then generalised to non-linearly polarized waves which exhibit the maximum two degrees of freedom of polarization.Comment: Latex file, 17 pages, accepted for publication in International Journal of Modern Physics

    Nonet Symmetry and Two-Body Decays of Charmed Mesons

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    The decay of charmed mesons into pseudoscalar (P) and vector (V) mesons is studied in the context of nonet symmetry. We have found that it is badly broken in the PP channels and in the P sector of the PV channels as expected from the non-ideal mixing of the \eta and the \eta'. In the VV channels, it is also found that nonet symmetry does not describe the data well. We have found that this discrepancy cannot be attributed entirely to SU(3) breaking at the usual level of 20--30%. At least one, or both, of nonet and SU(3) symmetry must be very badly broken. The possibility of resolving the problem in the future is also discussed.Comment: 9 pages, UTAPHY-HEP-
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