15,783 research outputs found

    Information and Communication Technologies and Informal Scholarly Communication: A Review of the Social Oriented Research

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    This article reviews and analyzes findings from research on computer mediated informal scholarly communication. Ten empirical research papers, which show the effects and influences of information & communication technologies (ICTs), or the effects of social contexts on ICTs use in informal scholarly communication, were analyzed and compared. Types of ICTs covered in those studies include e-mails, collaboratories, and electronic forums. The review shows that most of the empirical studies examined the ICTs use effects or consequences. Only a few studies examined the social shaping of ICTs and ICT uses in informal scholarly communication. Based on comparisons of the empirical findings this article summarizes the ICT use effects/consequences as identified in the studies into seven categories and discusses their implications

    Quantum Impurity in Luttinger Liquid: Universal Conductance with Entanglement Renormalization

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    We study numerically the universal conductance of Luttinger liquids wire with a single impurity via the Muti-scale Entanglement Renormalization Ansatz (MERA). The scale invariant MERA provides an efficient way to extract scaling operators and scaling dimensions for both the bulk and the boundary conformal field theories. By utilizing the key relationship between the conductance tensor and ground-state correlation function, the universal conductance can be evaluated within the framework of the boundary MERA. We construct the boundary MERA to compute the correlation functions and scaling dimensions for the Kane-Fisher fixed points by modeling the single impurity as a junction (weak link) of two interacting wires. We show that the universal behavior of the junction can be easily identified within the MERA and argue that the boundary MERA framework has tremendous potential to classify the fixed points in general multi-wire junctions.Comment: 14 pages, 18 figure

    Higher-order solutions to non-Markovian quantum dynamics via hierarchical functional derivative

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    Solving realistic quantum systems coupled to an environment is a challenging task. Here we develop a hierarchical functional derivative (HFD) approach for efficiently solving the non-Markovian quantum trajectories of an open quantum system embedded in a bosonic bath. An explicit expression for arbitrary order HFD equation is derived systematically. Moreover, it is found that for an analytically solvable model, this hierarchical equation naturally terminates at a given order and thus becomes exactly solvable. This HFD approach provides a systematic method to study the non-Markovian quantum dynamics of an open system coupled to a bosonic environment.Comment: 5 pages, 2 figure

    High Efficiency Concurrent Embedded Block Coding Architecture for JPEG 2000

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    [[abstract]]Embedded block coding with optimized truncation (EBCOT) is the most important part of JPEG 2000. Due to the bit level operation and the three-pass scanning technique, the EBCOT may take more than 50% operation time in the JPEG 2000. This paper presents a high efficiency concurrent EBCOT(HECEBC) entropy encoder hardware architecture. The proposed HECEBC can concurrently process the four samples in a stripe column. Furthermore this architecture can be extended to process several stripe columns concurrently for the JPEG 2000 to accomplish high resolution applications in real time. Besides, the HECEBC uses the technique of concentrated context window to stabilize the Context-Decision (CX-D) output to relax the load in between the arithmetic encoder (AE) and the parallel-in-serial-out (PISO) buffer to triple the EBC performance.[[notice]]補正完畢[[incitationindex]]EI[[booktype]]紙
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