938 research outputs found

    Faster Compact On-Line Lempel-Ziv Factorization

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    We present a new on-line algorithm for computing the Lempel-Ziv factorization of a string that runs in O(NlogN)O(N\log N) time and uses only O(Nlogσ)O(N\log\sigma) bits of working space, where NN is the length of the string and σ\sigma is the size of the alphabet. This is a notable improvement compared to the performance of previous on-line algorithms using the same order of working space but running in either O(Nlog3N)O(N\log^3N) time (Okanohara & Sadakane 2009) or O(Nlog2N)O(N\log^2N) time (Starikovskaya 2012). The key to our new algorithm is in the utilization of an elegant but less popular index structure called Directed Acyclic Word Graphs, or DAWGs (Blumer et al. 1985). We also present an opportunistic variant of our algorithm, which, given the run length encoding of size mm of a string of length NN, computes the Lempel-Ziv factorization on-line, in O(mmin{(loglogm)(loglogN)logloglogN,logmloglogm})O\left(m \cdot \min \left\{\frac{(\log\log m)(\log \log N)}{\log\log\log N}, \sqrt{\frac{\log m}{\log \log m}} \right\}\right) time and O(mlogN)O(m\log N) bits of space, which is faster and more space efficient when the string is run-length compressible

    Spin polarization in a T-shape conductor induced by strong Rashba spin-orbit coupling

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    We investigate numerically the spin polarization of the current in the presence of Rashba spin-orbit interaction in a T-shaped conductor proposed by A.A. Kiselev and K.W. Kim (Appl. Phys. Lett. {\bf 78} 775 (2001)). The recursive Green function method is used to calculate the three terminal spin dependent transmission probabilities. We focus on single-channel transport and show that the spin polarization becomes nearly 100 % with a conductance close to e2/he^{2}/h for sufficiently strong spin-orbit coupling. This is interpreted by the fact that electrons with opposite spin states are deflected into an opposite terminal by the spin dependent Lorentz force. The influence of the disorder on the predicted effect is also discussed. Cases for multi-channel transport are studied in connection with experiments

    Lateness Gene Concerning Photosensitivity Increases Yield, by Applying Low to High Levels of Fertilization, in Rice, a Preliminary Report

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    Various genes controlling heading time have been reported in rice. An isogenic-line pair of late and early lines “L” and “E” were developed from progenies of the F1 of Suweon 258 × an isogenic line of IR36 carrying Ur1 gene. The lateness gene for photosensitivity that causes the difference between L and E was tentatively designated as “Ex(t)”, although it's chromosomal location is unknown. The present study was conducted to examine the effects of Ex(t) on yield and related traits in a paddy field in two years. Chemical fertilizers containing N, P2O5 and K2O were applied at the nitrogen levels of 4.00, 9.00 and 18.00 g/m2 in total, being denoted by "N4", "N9" and "N18", respectively, in 2014. L was later in 80%-heading by 18 or 19 days than E. Regarding total brown rice yield (g/m2), L and E were 635 and 577, 606 and 548, and 590 and 501, respectively, at N18, N9 and N4, indicating that Ex(t) increased this trait by 10 to 18%. Ex(t) increased yield of brown rice with thickness above 1.5mm (g/m2), by 9 to 15%. Ex(t) increased spikelet number per panicle by 16 to 22% and spikelet number per m2 by 11 to 18%. Thousand-grain weight (g) was 2 to 4% lower in L than in E. L was not significantly different from E in ripened-grain percentage. Hence, Ex(t) increased yield by increasing spikelet number per panicle. It is suggested that Ex(t) could be utilized to develop high yielding varieties for warmer districts of the temperate zone

    Explosions inside Ejecta and Most Luminous Supernovae

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    The extremely luminous supernova SN2006gy is explained in the same way as other SNIIn events: light is produced by a radiative shock propagating in a dense circumstellar envelope formed by a previous weak explosion. The problems in the theory and observations of multiple-explosion SNe IIn are briefly reviewed.Comment: 9 pages, 6 figures, LateX aipproc.cls. A bit more details and color added to Fig.3. The 10th International Symposium on Origin of Matter and Evolution of Galaxies (OMEG07), Sapporo, Japan, December 200
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