22,824 research outputs found

    Inducing Effect on the Percolation Transition in Complex Networks

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    Percolation theory concerns the emergence of connected clusters that percolate through a networked system. Previous studies ignored the effect that a node outside the percolating cluster may actively induce its inside neighbours to exit the percolating cluster. Here we study this inducing effect on the classical site percolation and K-core percolation, showing that the inducing effect always causes a discontinuous percolation transition. We precisely predict the percolation threshold and core size for uncorrelated random networks with arbitrary degree distributions. For low-dimensional lattices the percolation threshold fluctuates considerably over realizations, yet we can still predict the core size once the percolation occurs. The core sizes of real-world networks can also be well predicted using degree distribution as the only input. Our work therefore provides a theoretical framework for quantitatively understanding discontinuous breakdown phenomena in various complex systems.Comment: Main text and appendices. Title has been change

    A novel multipath-transmission supported software defined wireless network architecture

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    The inflexible management and operation of today\u27s wireless access networks cannot meet the increasingly growing specific requirements, such as high mobility and throughput, service differentiation, and high-level programmability. In this paper, we put forward a novel multipath-transmission supported software-defined wireless network architecture (MP-SDWN), with the aim of achieving seamless handover, throughput enhancement, and flow-level wireless transmission control as well as programmable interfaces. In particular, this research addresses the following issues: 1) for high mobility and throughput, multi-connection virtual access point is proposed to enable multiple transmission paths simultaneously over a set of access points for users and 2) wireless flow transmission rules and programmable interfaces are implemented into mac80211 subsystem to enable service differentiation and flow-level wireless transmission control. Moreover, the efficiency and flexibility of MP-SDWN are demonstrated in the performance evaluations conducted on a 802.11 based-testbed, and the experimental results show that compared to regular WiFi, our proposed MP-SDWN architecture achieves seamless handover and multifold throughput improvement, and supports flow-level wireless transmission control for different applications

    4,4β€²-{[1,1β€²-MethylΒ­enebis(naphthalene-2,1-diΒ­yl)]bisΒ­(Β­oxymethylΒ­ene)}diΒ­benzoΒ­nitrile

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    There are two independent molΒ­ecules in the asymmetric unit of the title compound, C37H26N2O2. The crystal structure is stabilized by a weak intraΒ­molecular hydrogen bond as well as Cβ€”Hβ‹―Ο€ interΒ­actions

    Control and mitigation of microwave crosstalk effect with superconducting qubits

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    Improving gate performance is vital for scalable quantum computing. The universal quantum computing also requires the gate fidelity to reach a high level. For superconducting quantum processor, which operates in the microwave band, the single-qubit gates are usually realized with microwave driving. The crosstalk between microwave pulses is a non-negligible error source. In this article, we propose an error mitigation scheme to address this crosstalk issue for single-qubit gates. There are three steps in our method. First, by controlling the detuning between qubits, the microwave induced classical crosstalk error can be constrained within the computational subspace. Second, by applying the general decomposition procedure, arbitrary single-qubit gate can be decomposed as a sequence of X\sqrt{X} and virtual Z gates. Finally, by optimizing the parameters in virtual Z gates, the error constrained in the computational space can be corrected. Using our method, no additional compensation signals are needed, arbitrary single-qubit gate time will not be prolonged, and the circuit depth containing simultaneous single-qubit gates will also not increase. The simulation results show that, in specific regime of qubit-qubit detuning, the infidelities of simultaneous single-qubit gates can be as low as which without microwave crosstalk

    Environment-Centric Safety Requirements forAutonomous Unmanned Systems

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    Autonomous unmanned systems (AUS) emerge to take place of human operators in harsh or dangerous environments. However, such environments are typically dynamic and uncertain, causing unanticipated accidents when autonomous behaviours are no longer safe. Even though safe autonomy has been considered in the literature, little has been done to address the environmental safety requirements of AUS systematically. In this work, we propose a taxonomy of environment-centric safety requirements for AUS, and analyse the neglected issues to suggest several new research directions towards the vision of environment-centric safe autonomy

    Doxycycline inhibits the infiltration of inflammatory cells in rat alkali burn corneas

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    AIM: To investigate the inhibited effect of Doxycycline on the infiltration of inflammatory cells in rat alkali burn corneas. METHODS: Corneas of 32 SD rats were injured with 1mol/L NaOH, then divided into two groups: control and doxycycline-treated. All agents were administered topically 4 times daily. Slit-lamp microscope was performed and inflammatory index was calculated at 3, 7, 14 and 21 days after injury. Then 4 rats were randomly sacrificed and each cornea was divided into two parts, one for histopathology, the other for ICAM-1 ELISA assay. RESULTS:In control group, the inflammatory index and the number of inflammatory cell was higher than the doxycycline-treated dramatically at all time points(P<0.05). Compared with control group, corneal ICAM-1 expression decreased significantly in doxycycline-treated group at all time points(P < 0.05). CONCLUSION:Doxycycline may inhibit inflammatory cell infiltration by down-regulating ICAM-1 expression
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