17,184 research outputs found

    Parity-violating πNN\pi NN coupling constant from the flavor-conserving effective weak chiral Lagrangian

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    We investigate the parity-violating pion-nucleon-nucleon coupling constant hπNN1h^1_{\pi NN}, based on the chiral quark-soliton model. We employ an effective weak Hamiltonian that takes into account the next-to-leading order corrections from QCD to the weak interactions at the quark level. Using the gradient expansion, we derive the leading-order effective weak chiral Lagrangian with the low-energy constants determined. The effective weak chiral Lagrangian is incorporated in the chiral quark-soliton model to calculate the parity-violating πNN\pi NN constant hπNN1h^1_{\pi NN}. We obtain a value of about 10710^{-7} at the leading order. The corrections from the next-to-leading order reduce the leading order result by about 20~\%.Comment: 12 page

    Outage-based ergodic link adaptation for fading channels with delayed CSIT

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    Link adaptation in which the transmission data rate is dynamically adjusted according to channel variation is often used to deal with time-varying nature of wireless channel. When channel state information at the transmitter (CSIT) is delayed by more than channel coherence time due to feedback delay, however, the effect of link adaptation can possibly be taken away if this delay is not taken into account. One way to deal with such delay is to predict current channel quality given available observation, but this would inevitably result in prediction error. In this paper, an algorithm with different view point is proposed. By using conditional cdf of current channel given observation, outage probability can be computed for each value of transmission rate RR. By assuming that the transmission block error rate (BLER) is dominated by outage probability, the expected throughput can also be computed, and RR can be determined to maximize it. The proposed scheme is designed to be optimal if channel has ergodicity, and it is shown to considerably outperform conventional schemes in certain Rayleigh fading channel model

    Diversity at work matters in times of violent ethnic conflicts

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    Perceptions that colleagues prefer to work with ethnically similar others can be detrimental to the organisation, especially in regions marred by violence and adversity. Hyun-Jung Lee draws on her research from Sri Lanka to highlight that the level of ethnic diversity in workgroups matters as increasing the opportunities for positive contact can prove beneficial for a given organisation, as well as society more broadly

    How can firms manage multi-ethnic workforces in countries with violent ethnic conflicts?

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    Perceptions of ethnic homophily among colleagues can be detrimental to the firm, writes Hyun-Jung Le

    Rocky Road: East Asian International Students‟ Experience of Adaptation to Critical Thinking Way of Learning at U.S. Universities

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    This roundtable seeks to understand how Confucius-influenced East Asian international students learn to adapt to and participate in the countervailing Western pedagogy that fosters independent critical thinking and reflection and how these Asian students reconcile these seeming polarities as they engage in their doctoral studies at U.S. universities


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    This thesis describes the artist\u27s sculpture and jewelry/wall composition, which uses figurative forms representing simplified and exaggerated parts of the human body. The author describes how this artwork expresses the themes of community and coexistence in the human condition