58,143 research outputs found

    One Dimensional nnary Density Classification Using Two Cellular Automaton Rules

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    Suppose each site on a one-dimensional chain with periodic boundary condition may take on any one of the states 0,1,...,n10,1,..., n-1, can you find out the most frequently occurring state using cellular automaton? Here, we prove that while the above density classification task cannot be resolved by a single cellular automaton, this task can be performed efficiently by applying two cellular automaton rules in succession.Comment: Revtex, 4 pages, uses amsfont

    Simple ultraviolet-based soft-lithography process for fabrication of low-loss polymer polysiloxanes-based waveguides

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    A simple ultraviolet (UV)-based soft-lithography process is used for fabrication of polymer polysiloxanes (PSQ-L) waveguides. The imprint process is first done on the cladding PSQ-LL layer and is followed by a spin-coating step to fill the imprinted features with core PSQ-LH layer material. The optical loss of the straight PSQ-L waveguides is characterised by the Fabry-Perot method for the first time. Even with non-polished facet of the waveguide, the Fabry-Perot resonance spectrum is obtained. An upper limit scattering loss of the waveguide is extracted to be less than 0.8 +/- 0.2 dB/cm for TE mode and 1.3 +/- 0.2 dB/cm for TM mode at 1550 nm. The fully transferred pattern and low scattering loss proves it to be an effective way to replicate low-loss polymer PSQ-L-based waveguides

    On determination of the geometric cosmological constant from the OPERA experiment of superluminal neutrinos

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    The recent OPERA experiment of superluminal neutrinos has deep consequences in cosmology. In cosmology a fundamental constant is the cosmological constant. From observations one can estimate the effective cosmological constant Λeff\Lambda_{eff} which is the sum of the quantum zero point energy Λdarkenergy\Lambda_{dark energy} and the geometric cosmological constant Λ\Lambda. The OPERA experiment can be applied to determine the geometric cosmological constant Λ\Lambda. It is the first time to distinguish the contributions of Λ\Lambda and Λdarkenergy\Lambda_{dark energy} from each other by experiment. The determination is based on an explanation of the OPERA experiment in the framework of Special Relativity with de Sitter space-time symmetry.Comment: 7 pages, no figure

    Finding The Sign Of A Function Value By Binary Cellular Automaton

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    Given a continuous function f(x)f(x), suppose that the sign of ff only has finitely many discontinuous points in the interval [0,1][0,1]. We show how to use a sequence of one dimensional deterministic binary cellular automata to determine the sign of f(ρ)f(\rho) where ρ\rho is the (number) density of 1s in an arbitrarily given bit string of finite length provided that ff satisfies certain technical conditions.Comment: Revtex, uses amsfonts, 10 page

    Non-LTE analysis of copper abundances for the two distinct halo populations in the solar neighborhood

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    Two distinct halo populations were found in the solar neighborhood by a series of works. They can be clearly separated by [alpha\Fe] and several other elemental abundance ratios including [Cu/Fe]. Very recently, a non-local thermodynamic equilibrium (non-LTE) study revealed that relatively large departures exist between LTE and non-LTE results in copper abundance analysis. We aim to derive the copper abundances for the stars from the sample of Nissen et al (2010) with both LTE and non-LTE calculations. Based on our results, we study the non-LTE effects of copper and investigate whether the high-alpha population can still be distinguished from the low-alpha population in the non-LTE [Cu/Fe] results. Our differential abundance ratios are derived from the high-resolution spectra collected from VLT/UVES and NOT/FIES spectrographs. Applying the MAFAGS opacity sampling atmospheric models and spectrum synthesis method, we derive the non-LTE copper abundances based on the new atomic model with current atomic data obtained from both laboratory and theoretical calculations. The copper abundances determined from non-LTE calculations are increased by 0.01 to 0.2 dex depending on the stellar parameters compared with the LTE results. The non-LTE [Cu/Fe] trend is much flatter than the LTE one in the metallicity range -1.6<[Fe/H]<-0.8. Taking non-LTE effects into consideration, the high- and low-alpha stars still show distinguishable copper abundances, which appear even more clear in a diagram of non-LTE [Cu/Fe] versus [Fe/H]. The non-LTE effects are strong for copper, especially in metal-poor stars. Our results confirmed that there are two distinct halo populations in the solar neighborhood. The dichotomy in copper abundance is a peculiar feature of each population, suggesting that they formed in different environments and evolved obeying diverse scenarios.Comment: 9 pages, 7 figures, 2 table

    Weak coupling d-wave BCS superconductivity and unpaired electrons in overdoped La_{2-x}Sr_{x}CuO_{4} single crystals

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    The low-temperature specific heat (SH) of overdoped La_{2-x}Sr_{x}CuO_{4} single crystals (0.178=<x=<0.290) has been measured. For the superconducting samples (0.178=<x=<0.238), the derived gap values (without any adjusting parameters) approach closely onto the theoretical prediction \Delta_{0}=2.14k_{B}T_{c} for the weak-coupling d-wave BCS superconductivity. In addition, the residual term \gamma(0) of SH at H=0 increases with x dramatically when beyond x~0.22, and finally evolves into the value of a complete normal metallic state at higher doping levels, indicating growing amount of unpaired electrons. We argue that this large \gamma(0) cannot be simply attributed to the pair breaking induced by the impurity scattering, instead the phase separation is possible.Comment: 6 pages, 6 figures; Contents added; Accepted for publication in Phys. Rev.
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