15,290 research outputs found

    Difference of Oxide Hetero-Structure Junctions with Semiconductor Electronic Devices

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    Charge carrier injection performed in Pr0.7Ca0.3MnO3 (PCMO) hetero-structure junctions exhibits stable without electric fields and dramatic changes in both resistances and interface barriers, which are entirely different from behaviors of semiconductor devices. Disappearance and reversion of interface barriers suggest that the adjustable resistance switching of such hetero-structure oxide devices should associate with motion of charge carriers across interfaces. The results suggested that injected carriers should be still staying in devices and resulted in changes in properties, which guided to a carrier self-trapping and releasing picture in strongly correlated electronic framework. Observations in PCMO and oxygen deficient CeO2 devices show that oxides as functional materials could be used in microelectronics with some novel properties, in which interface is very important.Comment: 8 pages, 4 figure

    The skew energy of random oriented graphs

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    Given a graph GG, let GσG^\sigma be an oriented graph of GG with the orientation σ\sigma and skew-adjacency matrix S(Gσ)S(G^\sigma). The skew energy of the oriented graph GσG^\sigma, denoted by ES(Gσ)\mathcal{E}_S(G^\sigma), is defined as the sum of the absolute values of all the eigenvalues of S(Gσ)S(G^\sigma). In this paper, we study the skew energy of random oriented graphs and formulate an exact estimate of the skew energy for almost all oriented graphs by generalizing Wigner's semicircle law. Moreover, we consider the skew energy of random regular oriented graphs Gn,dσG_{n,d}^\sigma, and get an exact estimate of the skew energy for almost all regular oriented graphs.Comment: 12 pages. arXiv admin note: text overlap with arXiv:1011.6646 by other author

    On Efficiently Detecting Overlapping Communities over Distributed Dynamic Graphs

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    Modern networks are of huge sizes as well as high dynamics, which challenges the efficiency of community detection algorithms. In this paper, we study the problem of overlapping community detection on distributed and dynamic graphs. Given a distributed, undirected and unweighted graph, the goal is to detect overlapping communities incrementally as the graph is dynamically changing. We propose an efficient algorithm, called \textit{randomized Speaker-Listener Label Propagation Algorithm} (rSLPA), based on the \textit{Speaker-Listener Label Propagation Algorithm} (SLPA) by relaxing the probability distribution of label propagation. Besides detecting high-quality communities, rSLPA can incrementally update the detected communities after a batch of edge insertion and deletion operations. To the best of our knowledge, rSLPA is the first algorithm that can incrementally capture the same communities as those obtained by applying the detection algorithm from the scratch on the updated graph. Extensive experiments are conducted on both synthetic and real-world datasets, and the results show that our algorithm can achieve high accuracy and efficiency at the same time.Comment: A short version of this paper will be published as ICDE'2018 poste

    Rainbow kk-connectivity of random bipartite graphs

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    A path in an edge-colored graph GG is called a rainbow path if no two edges of the path are colored the same. The minimum number of colors required to color the edges of GG such that every pair of vertices are connected by at least kk internally vertex-disjoint rainbow paths is called the rainbow kk-connectivity of the graph GG, denoted by rck(G)rc_k(G). For the random graph G(n,p)G(n,p), He and Liang got a sharp threshold function for the property rck(G(n,p))≀drc_k(G(n,p))\leq d. In this paper, we extend this result to the case of random bipartite graph G(m,n,p)G(m,n,p).Comment: 15 pages. arXiv admin note: text overlap with arXiv:1012.1942 by other author
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