1,720,974 research outputs found
Calculation of fast neutron dose in plastic-coated optical fibres
No full textS.466-471The dose of fast neutrons in optical fibres with hydrogen-containing coating materials is considerably increased by energetic recoil protons. Their contribution to the dose in a SiO2 fibre core is calculated by the Monte Carlo method for different fibre geometries and a fibre optic cable. With 14 MeV neutrons the dose in a single fibre is increased by about 21 %, whereas in fibre bundles the dose increase can reach about 170 %. Maximum dose enhancement in fibre bundles (about 610 %) occurs at neutron energies around 5.5 MeV. The dose increase caused by 14 MeV neutrons in the fibre of a typical laboratory cable is about 124 %
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe 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
A proposed Procedure for Standardizing the Relationship between the Directional Dose Equivalent and Neutron Fluence.
No full textA simple formalism has been employed to average data on neutron fluence-to-directional dose equivalent conversion factors, h'(10;En,a), as given by three different research groups. h'(10;En,a) is numerically represented as the product of the neutron fluence-to-ambient dose equivalent conversion factor, h* and a simple expansion using only 15 pairs of coefficients for describing the angular dependence in the neutron energy region from thermal up to En = 20 MeV. Good agreement between the fit, the inputed data and more recent data which were not included in the evaluation has been obtained. The ICRU sphere may serve as the defining phantom for operational quantities for individual radiation protection, restricted, however, to irradiation from the frontal half-space
Calculation of fast neutron dose in plastic-coated optical fibres
No full textS.1570-1575The dose of fast neutrons in optical fibres with hydrogen-containing coating materials is considerably increased by energetic recoil protons. Their contribution to the dose in a Si0-2 fibre core is calculated by the Monte Carlo method for different fibre geometries and a fibre optic cable. With 14 MeV neutrons the dose in a single fibre is increased by about 21 per cent whereas in fibre bundles the dose increase can reach about 170 per cent. Maximum dose enhancement in fibre bundles (about 610 per cent) occurs at neutron energies around 5.5 MeV. The dose increase caused by 14 MeV neutrons in the fibre of a typical laboratory cable is about 124 per cent.45Nr.
Variations on the Author
Get PDF“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
Get PDFWe 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
Dispelling the Myths Behind First-author Citation Counts
Get PDFWe 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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