1,721,034 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
Mesures de sections efficaces d'ionisation et analyses d'objets du patrimoine avec des faisceaux d'ions légers aux énergies des accélérateurs médicaux
No full textThe development of proton therapy and cyclotrons for the production of radioisotopes for medicine has opened up a multitude of high-energy accelerators for ion beam analysis techniques. The high-energy PIXE method is developed at the ARRONAX cyclotron with proton beams, but also alpha particles at energies up to 70 MeV. The use of a high-energy beam allows the analysis of thick objects while limiting the damage aspect. Firstly, measurements of ionisation cross sections were carried out. They allowed to validate the RECPSSR model for elements with an atomic number Z ≥ 42 and to optimise a fitting function for elements whose values are poorly reproduced by the model. In a second phase, two applications of the PIXE method at high energy were carried out on the collections of the Dobrée Museum in Nantes. One of the studies concerned the analysis of seal matrices in order to determine their composition and to be able to classify them. The other study was on heavy silver coins from the 16th century, where the objective was to find the trace elements (Gold and Indium) allowing the provenance of the silver ore to be traced.Le développement de la protonthérapie et des cyclotrons de productions de radio-isotopes pour la médecine permet d’ouvrir aux techniques d’analyse par faisceaux d’ions une multitude d’accélérateurs de plusieurs dizaines de MeV. La méthode PIXE à haute énergie est développée au cyclotron ARRONAX avec des faisceaux de protons, mais aussi des particules alpha à des énergies pouvant atteindre 70 MeV. L’utilisation d’un faisceau de haute énergie permet l’analyse d’objet épais tout en limitant l’aspect d’endommagement.Dans un premier temps, des mesures de sections efficaces d’ionisation ont été réalisées. Elles ont permis de valider le modèle RECPSSR pour les éléments avec un numéro atomique Z ≥ 42 et d’optimiser une fonction d’ajustement pour les éléments dont les valeurs sont mal reproduites par le modèle. Dans un second temps, deux applications de la méthode PIXE à haute énergie ont été réalisées sur les collections du Musée Dobrée à Nantes. L'une des études a concerné l'analyse de matrices de sceaux afin de déterminer la composition et de pouvoir ensuite les classifier. L'autre étude était sur des pièces d'argent lourdes du XVIe siècle, où l'objectif était de retrouver les éléments traces (Or et Indium) permettant de retracer la provenance du minerai d'argent
Mesures de sections efficaces d'ionisation et analyses d'objets du patrimoine avec des faisceaux d'ions légers aux énergies des accélérateurs médicaux
No full textThe development of proton therapy and cyclotrons for the production of radioisotopes for medicine has opened up a multitude of high-energy accelerators for ion beam analysis techniques. The high-energy PIXE method is developed at the ARRONAX cyclotron with proton beams, but also alpha particles at energies up to 70 MeV. The use of a high-energy beam allows the analysis of thick objects while limiting the damage aspect. Firstly, measurements of ionisation cross sections were carried out. They allowed to validate the RECPSSR model for elements with an atomic number Z ≥ 42 and to optimise a fitting function for elements whose values are poorly reproduced by the model. In a second phase, two applications of the PIXE method at high energy were carried out on the collections of the Dobrée Museum in Nantes. One of the studies concerned the analysis of seal matrices in order to determine their composition and to be able to classify them. The other study was on heavy silver coins from the 16th century, where the objective was to find the trace elements (Gold and Indium) allowing the provenance of the silver ore to be traced.Le développement de la protonthérapie et des cyclotrons de productions de radio-isotopes pour la médecine permet d’ouvrir aux techniques d’analyse par faisceaux d’ions une multitude d’accélérateurs de plusieurs dizaines de MeV. La méthode PIXE à haute énergie est développée au cyclotron ARRONAX avec des faisceaux de protons, mais aussi des particules alpha à des énergies pouvant atteindre 70 MeV. L’utilisation d’un faisceau de haute énergie permet l’analyse d’objet épais tout en limitant l’aspect d’endommagement.Dans un premier temps, des mesures de sections efficaces d’ionisation ont été réalisées. Elles ont permis de valider le modèle RECPSSR pour les éléments avec un numéro atomique Z ≥ 42 et d’optimiser une fonction d’ajustement pour les éléments dont les valeurs sont mal reproduites par le modèle. Dans un second temps, deux applications de la méthode PIXE à haute énergie ont été réalisées sur les collections du Musée Dobrée à Nantes. L'une des études a concerné l'analyse de matrices de sceaux afin de déterminer la composition et de pouvoir ensuite les classifier. L'autre étude était sur des pièces d'argent lourdes du XVIe siècle, où l'objectif était de retrouver les éléments traces (Or et Indium) permettant de retracer la provenance du minerai d'argent
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
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