2,691 research outputs found

    The Games We Play Online and Offline: Making Wang-tta in Korea

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    This article presents an ethnographic analysis of case studies derived from fieldwork that was designed to consider the different ways Korean game players establish community online and offline. It considers ways Korean youth participate in activities at Korean computer game rooms, which can be thought of as “third places.

    Realizing quantum controlled phase-flip gate through quantum dot in silicon slow-light photonic crystal waveguide

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    We propose a scheme to realize controlled phase gate between two single photons through a single quantum dot in slow-light silicon photonic crystal waveguide. Enhanced Purcell factor and beta factor lead to high gate fidelity over broadband frequencies compared to cavity-assisted system. The excellent physical integration of this silicon photonic crystal waveguide system provides tremendous potential for large-scale quantum information processing.Comment: 9 pages, 3 figure

    Linear scaling computation of the Fock matrix. IX. Parallel computation of the Coulomb matrix

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    We present parallelization of a quantum-chemical tree-code [J. Chem. Phys. {\bf 106}, 5526 (1997)] for linear scaling computation of the Coulomb matrix. Equal time partition [J. Chem. Phys. {\bf 118}, 9128 (2003)] is used to load balance computation of the Coulomb matrix. Equal time partition is a measurement based algorithm for domain decomposition that exploits small variation of the density between self-consistent-field cycles to achieve load balance. Efficiency of the equal time partition is illustrated by several tests involving both finite and periodic systems. It is found that equal time partition is able to deliver 91 -- 98 % efficiency with 128 processors in the most time consuming part of the Coulomb matrix calculation. The current parallel quantum chemical tree code is able to deliver 63 -- 81% overall efficiency on 128 processors with fine grained parallelism (less than two heavy atoms per processor).Comment: 7 pages, 6 figure

    A comparative study between x-rays and gamma-rays irradiation on electrical characteristics of bipolar junction transistors (BJTS)

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    Irradiation impact of gamma rays and X-rays on bipolar junction transistors (BJTs) in terms of electronic excitation due to transfer of energy and subsequent ionization, as well as energy transfer to atomic nuclei is studied using in-situ method. Comparison is made on the electrical characteristics of the devices under test (DUT) for various collecting current at two different operating mode. Both temporary and permanent damages in DUTs are found to be induced by energy transfer from the irradiation by gamma-rays and X-rays, depending upon total dose absorbed and current drive. Increased probability of recombination, due to creation of electron–hole pairs at the base region is found to be the most significant radiation damage in BJTs, as it leads to decrease in electron flux reaching the collector region

    Cryogenic spectroscopy of ultra-low density colloidal lead chalcogenide quantum dots on chip-scale optical cavities towards single quantum dot near-infrared cavity QED

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    We present evidence of cavity quantum electrodynamics from a sparse density of strongly quantum-confined Pb-chalcogenide nanocrystals (between 1 and 10) approaching single-dot levels on moderately high-Q mesoscopic silicon optical cavities. Operating at important near-infrared (1500-nm) wavelengths, large enhancements are observed from devices and strong modifications of the QD emission are achieved. Saturation spectroscopy of coupled QDs is observed at 77K, highlighting the modified nanocrystal dynamics for quantum information processing.Comment: * new additional figures and text * 10 pages, 5 figure

    Online Gaming and the Interactional Self: Identity interplay in Situated Practice

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    In recent years the popular media have asserted that massively multiplayer online role playing games (MMORPGS) are highly addictive. According to popular belief, these games have caused players to forsake “real life” obligations and “significant” offline relationships in order to pursue the “fake” and “trivial” online. This article presents an examination of online games in a broader context by linking the online world of gamers with their offline worlds

    The 2-rotational Steiner triple systems of order 25

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    AbstractIn this paper, we enumerate the 2-rotational Steiner triple systems of order 25. There are exactly 140 pairwise non-isomorphic such designs. All these designs have full automorphism groups of order 12. We also investigate the existence of subsystems and quadrilaterals in these designs

    A Scalable QoS Scheduling Architecture For WiMAX Multi-Hop Relay Networks.

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    WiMAX Mobile Multi-hop Relay (MMR) network has been introduced to increase the capacity and extend the coverage area of a single WiMAX Base Station (BS) by the use of a Relay Station (RS)

    Temperature-tuning of near-infrared monodisperse quantum dot solids at 1.5 um for controllable Forster energy transfer

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    We present the first time-resolved cryogenic observations of Forster energy transfer in large, monodisperse lead sulphide quantum dots with ground state transitions near 1.5 um (0.83 eV), in environments from 160 K to room temperature. The observed temperature-dependent dipole-dipole transfer rate occurs in the range of (30-50 ns)^(-1), measured with our confocal single-photon counting setup at 1.5 um wavelengths. By temperature-tuning the dots, 94% efficiency of resonant energy transfer can be achieved for donor dots. The resonant transfer rates match well with proposed theoretical models

    The prevalence of insomnia in the general population in China: A meta-analysis

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    This is the first meta-analysis of the pooled prevalence of insomnia in the general population of China. A systematic literature search was conducted via the following databases: PubMed, PsycINFO, EMBASE and Chinese databases (China National Knowledge Interne (CNKI), WanFang Data and SinoMed). Statistical analyses were performed using the Comprehensive Meta-Analysis program. A total of 17 studies with 115,988 participants met the inclusion criteria for the analysis. The pooled prevalence of insomnia in China was 15.0% (95% Confidence interval [CI]: 12.1%-18.5%). No significant difference was found in the prevalence between genders or across time period. The pooled prevalence of insomnia in population with a mean age of 43.7 years and older (11.6%; 95% CI: 7.5%-17.6%) was significantly lower than in those with a mean age younger than 43.7 years (20.4%; 95% CI: 14.2%-28.2%). The prevalence of insomnia was significantly affected by the type of assessment tools (Q = 14.1, P = 0.001). The general population prevalence of insomnia in China is lower than those reported in Western countries but similar to those in Asian countries. Younger Chinese adults appear to suffer from more insomnia than older adults
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