7,720 research outputs found

    On Source Density Evolution of Gamma-ray Bursts

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    Recent optical afterglow observations of gamma-ray bursts indicate a setting and distance scale that many relate to star-formation regions. In this paper, we use and a set of artificial trigger thresholds to probe several potential GRB source density evolutionary scenarios. In particular, we compare a uniform subset of BATSE 4B data to cosmological scenarios where GRBs evolve as the comoving density, the star formation rate, the QSO rate, and the SN Type Ic rate. Standard candle bursts with power-law spectra and a universe without vacuum energy were assumed. Our results significantly favor a comoving density model, implying that GRB source density evolution is weaker than expected in these evolutionary scenarios. GRB density might still follow star-formation rates given proper concurrent GRB luminosity evolution, significant beaming, significant error in standard candle assumptions, or were a significant modification of star formation rate estimates to occur.Comment: 12 pages, 4 figures, accepted by Ap

    A dynamic theory of holdup

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    game theory;investment;bargaining

    Watermarking FPGA Bitfile for Intellectual Property Protection

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    Intellectual property protection (IPP) of hardware designs is the most important requirement for many Field Programmable Gate Array (FPGA) intellectual property (IP) vendors. Digital watermarking has become an innovative technology for IPP in recent years. Existing watermarking techniques have successfully embedded watermark into IP cores. However, many of these techniques share two specific weaknesses: 1) They have extra overhead, and are likely to degrade performance of design; 2) vulnerability to removing attacks. We propose a novel watermarking technique to watermark FPGA bitfile for addressing these weaknesses. Experimental results and analysis show that the proposed technique incurs zero overhead and it is robust against removing attacks

    Research on control strategy for Three-Phase PWM Voltage Source Rectifier

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    Author name used in this publication: K. W. E. ChengVersion of RecordPublishe

    Real-time simulation and experiment platform for switched reluctance motor

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    2006-2007 > Academic research: refereed > Refereed conference paperVersion of RecordPublishe
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