1,721,324 research outputs found

    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

    Preliminary design of the recombination dipole for future circular collider

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    The Future Circular Collider (FCC) project aims at producing a conceptual design of a post-Large Hadron Collider (LHC) particle collider, able to reach higher beam energy with higher luminosity both for proton-proton and electron-electron configurations. In the proton-proton configuration, the FCC must be able to circulate 50 GeV protons in a 100 km tunnel. A key role in this project is played by the R and D on superconducting magnets, which must be able to produce magnetic fields significantly higher than in the LHC. Beside the bending dipoles, which must produce a 16 T field, also the multiplets in the interaction regions represent a technological challenge: As an example, the recombination dipoles are expected to produce a field of 10 T and therefore Nb 3 Sn must be used. In this contribution, the preliminary design of a double aperture recombination dipole for the FCC will be presented in details. It features a two layers, cosine-theta design, in order to produce the required field of 10 T in the bore. The magnetic field has the same direction in both apertures, generating a not negligible crosstalk which is minimized using asymmetric coils. The magnetic design will be described, focusing on the main features of the Nb 3 Sn conductor. The winding configuration and the iron yoke shape have been optimized to achieve a suitable field quality. A solution for the mechanical design will also be presented: The necessary prestress will be given by the so-called 'bladder and keys' concept, which avoids the collaring and allows to obtain, thanks to differential thermal contraction of the components, most of the prestress after the cool down, when the Nb 3 Sn is less brittle. The proposed solution fulfills all the standard requirements both from the magnetic point of view, i.e., field quality and current margin, and from the mechanical one, with a viable construction schema and reasonably low stress on conductor and support structures, during all the magnet operations

    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

    Sensitivity estimates for diffuse, point-like, and extended neutrino sources with KM3NeT/ARCA

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    The identification of cosmic objects emitting high energy neutrinos could provide new insights about the Universe and its active sources. The existence of these cosmic neutrinos has been proven by the IceCube Collaboration, but the big question of which sources these neutrinos originate from, remains unanswered. The KM3NeT detector for Astroparticle Research with Cosmics in the Abyss (ARCA), with a cubic kilometer instrumented volume, is currently being built in the Mediterranean Sea. It will excel at identifying cosmic neutrino sources due to its unprecedented angular resolution for muon neutrinos (< 0.2 degree for E > 10 TeV events). KM3NeT has a view of the sky complementary to IceCube, and is sensitive to neutrinos across a wide range of energies. In order to identify the signature of cosmic neutrino sources in the background of atmospheric neutrinos and muons, statistical methods are being developed and tested with Monte-Carlo pseudo-experiments. This contribution presents the most recent sensitivity estimates for diffuse, point-like, and extended neutrino sources with KM3NeT/ARCA

    Update on Mechanical Design of a Cosθ 16-T Bending Dipole for the Future Circular Collider

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    After the large hadron collider (LHC), a higher energy range must be explored to address the open questions in particle physics. A new generation of colliders will be necessary, able to accelerate both leptons and hadrons to energy higher than previous machines. The EuroCirCol European collaboration, in the framework of the future circular collider (FCC) project, has the aim to provide a design for a hadron collider that is able to accelerate protons to 50 TeV in a 80-100 km circumference tunnel. One of the most challenging task is the design of the bending dipole, which must be able to produce magnetic field as high as 16 T. In this paper, the state of art of the cos. option for the 16 T dipole for FCC is presented. In particular, the mechanical design will be described, showing that promising solutions have been found

    Dispelling the Myths Behind First-author Citation Counts

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    We conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more sophisticated methods

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    Pre-analysis of the WCLL breeding blanket mock-up neutronics experiment at the frascati neutron generator

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    The Water Cooled Lithium Lead (WCLL) is one of the breeding blanket (BB) concept candidate for the future European Demonstration Fusion Power Reactor (DEMO). In the frame of the EUROfusion Consortium, a WCLL BB mock-up neutronics experiment will be performed at the 14 MeV Frascati Neutron Generator (FNG) irradiation facility, devoted to the validation of the Tritium Breeding Ratio (TBR) and the shielding capability predicted by neutronics design calculations. It will include the assessment of the uncertainties on the calculated Tritium Production Rate (TPR) and the neutron/gamma attenuation which will be useful to evaluate design margins required to guarantee tritium self-sufficiency. In preparation of the future experiment, a detailed pre-analysis has been performed with the MCNP Monte Carlo code for the definition of the mock-up assembly and for the optimisation of the experimental setup. The WCLL mock-up has been designed in such a way that the essential nuclear features of the WCLL BB in DEMO can be represented in the experiment and the relevant nuclear quantities can be measurable with sufficient accuracy under FNG irradiation conditions, with several experimental techniques. This study reports the results of the pre-analysis: the optimised experimental layout and its representativeness of WCLL DEMO blanket
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