2,655 research outputs found

    Consumer Food Choices as a Reflection of Concerns about Nutritional Attributes

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    Economic growth changed household food consumption patterns in the Republic of Korea. Consumer survey data were used to identify concerns about fat, saturated fat, sodium, sugar, calories and protein consumption. Results showed income, age, household size and the geographic location significantly influenced consumer concerns with regard to these nutritional attributes.Consumer/Household Economics,

    Blandford-Znajek process as a gamma ray burst central engine

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    We investigate the possibility that gamma-ray bursts are powered by a central engine consisting of a black hole with an external magnetic field supported by a surrounding disk or torus. The rotational energy of the black hole can be extracted electromagnetically as a Poynting flux, a mechanism proposed by Blandford and Znajek(1977). Recently observed magnetars indicate that some compact objects have very high magnetic fields, up to 101510^{15} G, which is required to extract the energy within the duration of a GRB, i.e., in 1000 s or less. We demonstrate also that the Poynting flux need not be substantially dominated by the disk.Comment: 7 pages, no figure, paspconf.sty, to appear in Proceedings " Gamma Ray Bursts: The First Three Minutes", Gr\"aft{\aa}vallen, Sweden, Feb. 6 - 11, 199

    Consequences of the partial restoration of chiral symmetry in AdS/QCD

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    Chiral symmetry is an essential concept in understanding QCD at low energy. We treat the chiral condensate, which measures the spontaneous breaking of chiral symmetry, as a free parameter to investigate the effect of partially restored chiral symmetry on the physical quantities in the frame work of an AdS/QCD model. We observe an interesting scaling behavior among the nucleon mass, pion decay constant and chiral condensate. We propose a phenomenological way to introduce the temperature dependence of a physical quantity in the AdS/QCD model with the thermal AdS metric.Comment: 11 pages, 6 figure

    Coulomb Driven New Bound States at the Integer Quantum Hall States in GaAs/Al(0.3)Ga(0.7)As Single Heterojunctions

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    Coulomb driven, magneto-optically induced electron and hole bound states from a series of heavily doped GaAs/Al(0.3)Ga(0.7)As single heterojunctions (SHJ) are revealed in high magnetic fields. At low magnetic fields (nu > 2), the photoluminescence spectra display Shubnikov de-Haas type oscillations associated with the empty second subband transition. In the regime of the Landau filling factor nu < 1 and 1 < nu <2, we found strong bound states due to Mott type localizations. Since a SHJ has an open valence band structure, these bound states are a unique property of the dynamic movement of the valence holes in strong magnetic fields

    Application of Artificial Neural Network to Search for Gravitational-Wave Signals Associated with Short Gamma-Ray Bursts

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    We apply a machine learning algorithm, the artificial neural network, to the search for gravitational-wave signals associated with short gamma-ray bursts. The multi-dimensional samples consisting of data corresponding to the statistical and physical quantities from the coherent search pipeline are fed into the artificial neural network to distinguish simulated gravitational-wave signals from background noise artifacts. Our result shows that the data classification efficiency at a fixed false alarm probability is improved by the artificial neural network in comparison to the conventional detection statistic. Therefore, this algorithm increases the distance at which a gravitational-wave signal could be observed in coincidence with a gamma-ray burst. In order to demonstrate the performance, we also evaluate a few seconds of gravitational-wave data segment using the trained networks and obtain the false alarm probability. We suggest that the artificial neural network can be a complementary method to the conventional detection statistic for identifying gravitational-wave signals related to the short gamma-ray bursts.Comment: 30 pages, 10 figure
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