1,721,014 research outputs found
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
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
Online runtime verification competitions: How to possibly deal with their issues (Position paper)
No full textInternational audienceThis short paper presents a compilation of feedback about online runtime verification competitions from an active contestant. In particular, it points out several issues and how they could possibly be fixed
Une bibliothèque de typage dynamique en OCaml
No full textInternational audienceCet article présente une bibliothèque OCaml fournissant une représentation dynamique des types monomorphes, y compris pour les instances des types polymorphes et les types de données abstraits. Elle permet ainsi de voir les types OCaml comme des citoyens de première classe. Elle comble aussi le fossé séparant OCaml des langages dynamiques en mêlant vérications statiques et dynamiques des types. Nous nous concentrons ici sur le c÷ur de son implantation, ses propriétés théoriques et l'usage qui en est fait dans Frama-C, plateforme logicielle libre d'analyse statique de programmes C au sein de laquelle cette bibliothèque est distribuée
Relational Arithmetics for Abstract Interpretation Based Analysis of Numerical Accuracy Properties
No full textL'arithmétique à virgule flottante est l'approche la plus utilisée pour réaliser des calculs mathématiques reposant sur les nombres réels avec un ordinateur. Cependant, elle souffre d'un défaut : chaque opération peut introduire une erreur, c'est-à-dire une différence avec le résultat que nous aurions obtenu en utilisant des réels. Bien que ces erreurs soient très faibles, elles peuvent s'accumuler et provoquer des bugs ayant parfois des conséquences graves, en particulier dans des domaines critiques comme l'aéronautique ou le nucléaire. Il est donc nécessaire de pouvoir garantir que les erreurs introduites par l'utilisation de l'arithmétique flottante ne causent pas de problème, ou, dit autrement, qu'elles soient suffisamment faibles pour que le programme se comporte comme attendu. Pour répondre à ce besoin, nous proposons une analyse statique par interprétation abstraite, reposant sur un nouveau domaine abstrait, et calculant une sur-approximation des erreurs introduites par l'arithmétique flottante. Cette analyse repose sur l'interaction, au travers d'un produit réduit, entre deux conceptions de la notion d'erreur: l'erreur absolue, intuitive et permettant de mieux comprendre le programme analysé, et l'erreur relative, plus proche du fonctionnement de l'arithmétique flottante. Notre analyse repose sur la combinaison des arithmétiques affines et d'intervalles, et dispose de capacités de raisonnements relationnels. Cette combinaison a cependant des difficultés à traiter les opérations non linéaires, dont la précision impacte fortement l'évaluation des erreurs relatives. Nous proposons donc deux approches pour répondre à ce problème. La première consiste en différentes améliorations de cette combinaison, permettant d'évaluer plus précisément multiplications et divisions sans impacter significativement les performances. La seconde consiste en la définition d'une nouvelle arithmétique relationnelle, spécifiquement conçue pour représenter l'erreur relative. Par ailleurs, nous avons implémenté un prototype de notre analyse au sein de l'outil Frama-C/Eva. Les premiers résultats expérimentaux montrent l'intérêt de notre analyse par rapport à l'état de l'art.Floating point arithmetic is the most used approach to perform mathematical computations using real numbers with a computer. However, this approach has a default : each operation can introduce an error, that is, a difference with the result we would have obtained using real numbers. Even if those errors are very small, they can accumulate et provoke serious bugs, particularly in critical domains like aeronautics or nuclear energy production for example. Thus, we have to be able to guarantee that the errors introduced by the use of floating point arithmetic do not cause problems, in other words, that they are small enough for the program to behave as expected. To answer this need, we propose an abstract interpretation based static analysis, along with a new abstract domain, that computes an overapproximation of the errors introduced by floating point arithmetic. This analysis is based on the interaction, performed through a reduced product, between two conceptions of the concept of error : absolute error, intuitive and helpful to understand the analyzed program, and relative error, closer of floating point arithmetic functioning. Our analysis relies on the combination of affine and intervals arithmetics, and thus have relational reasoning capacities. However, this combination has difficulties dealing with non linear operations, whose precision has a huge impact on relative errors evaluations. Thus, we propose two approaches to tackle this problem. The first one consists of several improvements of this combination that help evaluating multiplications and divisions more precisely without impacting performances significantly. The second one consists of the definition of a new relational arithmetic, specifically designed to represent relative errors. Besides, we have implemented a prototype of our analysis within the Frama-C/Eva tool. The first experimental results enlighten the advantages of our analysis against state of the art tools
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