51,820 research outputs found

    Latency Optimal Broadcasting in Noisy Wireless Mesh Networks

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    In this paper, we adopt a new noisy wireless network model introduced very recently by Censor-Hillel et al. in [ACM PODC 2017, CHHZ17]. More specifically, for a given noise parameter p[0,1],p\in [0,1], any sender has a probability of pp of transmitting noise or any receiver of a single transmission in its neighborhood has a probability pp of receiving noise. In this paper, we first propose a new asymptotically latency-optimal approximation algorithm (under faultless model) that can complete single-message broadcasting task in D+O(log2n)D+O(\log^2 n) time units/rounds in any WMN of size n,n, and diameter DD. We then show this diameter-linear broadcasting algorithm remains robust under the noisy wireless network model and also improves the currently best known result in CHHZ17 by a Θ(loglogn)\Theta(\log\log n) factor. In this paper, we also further extend our robust single-message broadcasting algorithm to kk multi-message broadcasting scenario and show it can broadcast kk messages in O(D+klogn+log2n)O(D+k\log n+\log^2 n) time rounds. This new robust multi-message broadcasting scheme is not only asymptotically optimal but also answers affirmatively the problem left open in CHHZ17 on the existence of an algorithm that is robust to sender and receiver faults and can broadcast kk messages in O(D+klogn+polylog(n))O(D+k\log n + polylog(n)) time rounds.Comment: arXiv admin note: text overlap with arXiv:1705.07369 by other author

    KK-anonymous Signaling Scheme

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    We incorporate signaling scheme into Ad Auction setting, to achieve better welfare and revenue while protect users' privacy. We propose a new \emph{KK-anonymous signaling scheme setting}, prove the hardness of the corresponding welfare/revenue maximization problem, and finally propose the algorithms to approximate the optimal revenue or welfare

    Anisotropic intrinsic lattice thermal conductivity of phosphorene from first principles

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    Phosphorene, the single layer counterpart of black phosphorus, is a novel two-dimensional semiconductor with high carrier mobility and a large fundamental direct band gap, which has attracted tremendous interest recently. Its potential applications in nano-electronics and thermoelectrics call for a fundamental study of the phonon transport. Here, we calculate the intrinsic lattice thermal conductivity of phosphorene by solving the phonon Boltzmann transport equation (BTE) based on first-principles calculations. The thermal conductivity of phosphorene at 300K300\,\mathrm{K} is 30.15Wm1K130.15\,\mathrm{Wm^{-1}K^{-1}} (zigzag) and 13.65Wm1K113.65\,\mathrm{Wm^{-1}K^{-1}} (armchair), showing an obvious anisotropy along different directions. The calculated thermal conductivity fits perfectly to the inverse relation with temperature when the temperature is higher than Debye temperature (ΘD=278.66K\Theta_D = 278.66\,\mathrm{K}). In comparison to graphene, the minor contribution around 5%5\% of the ZA mode is responsible for the low thermal conductivity of phosphorene. In addition, the representative mean free path (MFP), a critical size for phonon transport, is also obtained.Comment: 5 pages and 6 figures, Supplemental Material available as http://www.rsc.org/suppdata/cp/c4/c4cp04858j/c4cp04858j1.pd
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