1,721,015 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
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
Contribution to blind side channel analysis, and search of compact S-boxes
No full textLa cryptographie est largement utilisée de nos jours, et les attaques par analyse de canaux auxiliaires sont une menace avérée. Afin de développer des contre-mesures adéquates, ces attaques sont constamment étudiées et améliorées. Ce document s’inscrit dans cette démarche et étudie les attaques par distributions jointes qui ont pour particularité de ne nécessiter ni le clair ni le chiffré contrairement aux attaques classiques. Premièrement, de nouvelles variantes qui améliorent cette attaque sont proposées. Elles consistent notamment à observer plus ou différentes variables intermédiaires, et à adapter les distributions théoriques en conséquence. Ensuite, une expérimentation sur microcontrôleur est proposée et valide l’efficacité de l’attaque en général hors simulations. Enfin, plusieurs solutions visant à compromettre des implémentations masquées sont proposées. Elles consistent à tirer profit de la réutilisation de certaines valeurs de masques sur plusieurs variables internes, ce qui résulte en la proposition des attaques quadrivariées. Un autre axe principal ayant pour sujet la construction de S-boxes compactes 8 bits est exploré dans ce document et a pour origine la participation au projet PACLIDO, dont l’un des buts est le développement d’un algorithme de cryptographie légère. La S-box est un composant essentiel des algorithmes de chiffrement et a pour rôle de les rendre résistants à la cryptanalyse classique.Malheureusement, ce composant est souvent très coûteux en nombre de portes logiques. Nous proposons deux méthodes de recherche de circuits compacts 8 bits composés de portes hybrides ANDXOR, et montrons quelques résultats proches de ceux qui se trouvent dans la littérature.Cryptography is widely used nowadays, and side channel attacks are known threats. In order to develop suitable countermeasures, these attacks are constantly studied and improved. This document is part with this approach and studies joint distributions attacks which do not need the plaintext nor the ciphertext, contrary to classical attacks. First, new variants which improve this attack are proposed. They mainly consist in observing more or different intermediate variables, and adapt theoretical distributions accordingly. Then, a practical experiment is done on a microcontroller which validates the attack apart from simulations. Finally, several solutions that compromise masked implementations are proposed. They consist in using the fact that some masks are reused on several internal variables, ending in the quadrivariate attacks proposal. An other main theme about 8 bits S-boxes construction is explored in this document, and originated from the participation to the PACLIDO project which aims to develop a lightweight cryptography algorithm. The S-box is a critical component of cryptographic algorithms and acts to make them resilient to classical cryptanalysis. Unfortunately, this component is often costly in terms of logical gates. We propose two methods for searching compact 8 bit circuits composed of hybrid gates ANDXOR, and show some results close to the literature
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
Study of the security of embedded cryptography algorithms facing power consumption analysis attacks
No full textLa cryptographie prend une place de plus en plus importante dans la vie des sociétés depuis que ses utilisateurs se rendent compte de son importance pour sécuriser divers aspects de la vie, depuis les moyens de paiement, de communication et de sauvegarde des éléments de la vie privée des citoyens, jusqu'à la sécurité nationale des pays et de leurs armées. Depuis une vingtaine d'années on sait que les algorithmes de cryptographie ne doivent pas seulement être sûrs mathématiquement parlant, mais que leurs implémentations dans un dispositif les rendent vulnérables à d'autres menaces par des voies d'informations alternatives : les canaux auxiliaires. Que ce soit la consommation électrique, le temps ou les émissions électromagnétiques, ... ces biais ont été évalués et depuis leur découverte les recherches de nouvelles attaques et protections se succèdent afin de garantir la sécurité des algorithmes. La présente thèse s'inscrit dans ce processus et présente plusieurs travaux de recherche traitant d'attaques et de contre-mesures dans le domaine de l'exploitation de canaux auxiliaires et d'injections de fautes. Une première partie présente des contributions classiques où l'on cherche à retrouver une clef cryptographique lorsque la seconde s’attelle à un domaine moins étudié pour l'instant consistant à retrouver les spécifications d'un algorithme tenu secret.Cryptography is taking an ever more important part in the life of societies since the users are realising the importance to secure the different aspects of life from citizens means of payment, communication and records of private life to the national securities and armies. During the last twenty years we learned that to mathematically secure cryptography algorithms is not enough because of the vulnerabilities brought by their implementations in a device through an alternative means to get information: side channels. Whether it is from power consumption, time or electromagnetic emissions ... those biases have been evaluated and, since their discovery, the researches of new attacks follow new countermeasures in order to guarantee security of algorithms. This thesis is part of this process and shows several research works about attacks and countermeasures in the fields of side channel and fault injections analysis. The first part is about classic contributions where an attacker wants to recover a secret key when the second part deals with the less studied field of secret specifications recovery
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