1,720,988 research outputs found
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe 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
Full text link“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
Full text linkWe 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
Extension of the nodal code DYN3D to SFR applications
Full text linkDYN3D is a well-established Light Water Reactor (LWR) simulation tool and is being extended for safety analyses of Sodium cooled Fast Reactors (SFRs) at the Helmholtz-Zentrum Dresden-Rossendorf. This thesis focuses on the first stage of the development process, that is, the extension and application of DYN3D for steady-state and transient SFR calculations on reactor core level.
In contrast to LWRs, the SFR behavior is especially sensitive to thermal expansions of the reactor components. Therefore, a new thermal-mechanical module accounting for thermal expansions is implemented into DYN3D. At first step, this module is capable of treating two important thermal expansion effects occurring within the core, namely axial expansion of fuel rods and radial expansion of diagrid.
In order to perform nodal calculations with DYN3D, pre-generated homogenized few-group cross sections (XS) are necessarily needed. Therefore, prior to the development of thermal expansion models, a general methodology for XS generation is established for SFR nodal calculations based on the use of the Monte Carlo code Serpent.
The new methodological developments presented in this thesis are verified against the Monte Carlo solutions of Serpent. Two SFR cores are used for testing: the large oxide core of the OECD/NEA benchmark and a smaller core from the Phenix end-of-life tests. Finally, the extended DYN3D is validated against selected IAEA benchmark tests on the Phenix end-of-life experiments that contain both steady-state and transient calculations.
The contribution to the SFR-related developments at the HZDR, as presented in this thesis, makes it possible of performing steady-state and transient calculations for SFRs on reactor core level by using DYN3D. With this study, the basis of the next stage of DYN3D developments is established, that is, the up-scale of SFR analysis to system level can continue by coupling with a sodium capable thermal-hydraulic system code.LR
Extension, validation, and optimization of Serpent/DYN3D/ATHLET code system for SFR applications
No full textThe sequence of codes Serpent/DYN3D has been developed by the Helmholtz-Zentrum Dresden-Rossendorf and successfully applied to core static and transient analyses of sodium-cooled fast reactors (SFRs). The successful application of the sequence to SFRs was made possible thanks to several recent development activities. The activities included modifications of DYN3D to account for in-core thermal expansions effects and development of a Serpent-based methodology for the generation of multi-group cross-sections (XSs). Despite the recent developments, the Serpent/DYN3D sequence presents still some limitations. That is, the domain of the sequence analyses is restricted to core-level and considerable computational efforts are required both to generate XS libraries for transient applications and perform related calculations. This thesis aims at overcoming such limitations through: The extension of the modeling domain of the sequence from core to whole SFR systems, the validation of the newly extended computational tool, and the optimization of the accuracy of solutions against computational efforts.
The extension of the analysis domain to SFR systems is achieved by coupling the sequence with the thermal hydraulics code ATHLET capable of modeling the liquid sodium flow. Included in the extension is the development of ATHLET-based modeling methodologies to account for the thermal expansions of out-of-core structures that may strongly affect the reactor neutronics. Verification and validation activities inherent to the extension of the coupled tool are performed against numerical and experimental benchmarks based on the Phénix and Superphénix reactor data. Options focused on the simplification of XS libraries are considered to optimize computational times while preserving the accuracy of solutions. The options include the selection of optimal condensed energy groups structure for SFR analyses and the representation of parametrized XSs via first-order derivatives.
The research activities conducted in this doctoral thesis led to the successful development and validation of a new computational platform for steady-state and transient analyses of SFR systems. The platform is currently applicable to the analyses of scenarios that do not involve sodium boiling or core damage. The options for the simplification of XS libraries and acceleration of neutronics calculations were implemented and tested revealing wide margins for significant speedup of analyses with the introduction of practically negligible errors.LR
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe 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
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
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