1,720,963 research outputs found

    LHCb VELO Upgrade: Technical Design Report

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    The upgraded LHCb VELO silicon vertex detector is a lightweight hybrid pixel detector capable of 40 MHz readout at a luminosity of 2×10^33 cm^−2 s^−1. The track reconstruction speed and precision is enhanced relative to the current VELO detector even at the high occupancy conditions of the upgrade, due to the pixel geometry and a closest distance of approach to the LHC beams of just 5.1 mm for the first sensitive pixel. Cooling is provided by evaporative CO2 circulating in microchannel cooling substrates. The detector contains 41 million 55μ×55μ pixels, read out by the custom developed VeloPix front end ASIC. The detector will start operation together with the rest of the upgraded LHCb experiment after the LHC LS2 shutdown, currently scheduled to end in 2019. This Technical Design Report describes the upgraded VELO system, planned construction and installation, and gives an overview of the expected detector performanc

    Multichannel Digital Pulse Processor for Bi-Dimensional Detector Arrays

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    We present an innovative readout and processing architecture for multi-channel applications that allows the direct connection to the output of the charge preamplifiers and grants the possibility to fully exploit advantages of digital processing. The processor is constituted by the collection of modules (3,2×2,8 in.). Each one manages 8 channels and integrates the hardware and firmware architecture to process the data. The power consumption of each module is below 5 W including analog front-end, ADC, and FPGA de-vice. Each module is connected by a serial line at 400 Mbit/s to a communication board, which collects information up to 64 detectors and delivers it to a reference host PC through USB 3.0. The complete architecture has been prototyped and teste

    LHCb Particle Identification Upgrade: Technical Design Report

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    The LHCb upgrade will take place in the second long shutdown of the LHC, currently scheduled to begin in 2018. The upgrade will enable the experiment to run at luminosities of 2 x 10^33 cm^-2 s^-1 and will read out data at a rate of 40MHz into a exible software-based trigger. All sub-detectors of LHCb will be re-designed to comply with these new operating conditions. This Technical Design Report presents the upgrade plans of the Ring Imaging Cherenkov (RICH) system, the calorimeter system and the muon system, which together provide the particle identication capabilities of the experiment

    Implementation of USB 3.0 Bus Controller in FPGA for Data Transfer in Multi-Channel Applications

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    In this contribution, we present a USB 3.0 controller in FPGA that allows the connection of a PC to a FPGA-based digital detection system, providing a constant real transfer rate of 3 Gb/s. The controller maps in the PC memory all the registers of the system into the FPGA device. In this way, with simple instructions C++/vb.net the user can fully configure the system and get data from it. The controller has been physically realized and tested

    Going Beyond Counting First Authors in Author Co-citation Analysis

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    The present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed

    Variations on the Author

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    “Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship

    Appropriate Similarity Measures for Author Cocitation Analysis

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    We provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
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