1,721,000 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
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
Contribution to the understanding and modeling of physical processes occurring during hybrid laser welding
No full textCes travaux présentent une recherche sur la physique du soudage hybride. La revue littéraire décrit les principaux processus physiques se produisant au cours de la combinaison Laser-arc, les principales réalisations et les problèmes rencontrés lors de l'analyse de ces processus. Les processus ont été étudiés pendant l'assemblage de matériaux de fortes épaisseurs. Deux configurations ont été utilisées. La première est le soudage d’un acier Superduplex en un seul passage, par Laser et arc distanciés. La seconde configuration est le soudage multipasse de l'acier 18MND5, où le faisceau Laser défocalisé intercepte le plasma d'arc électrique. Avec l'aide de la planification d'expérience, l'imagerie vidéo rapide, l'enregistrement des signaux électriques, la détermination de la température et des distorsions de l’assemblage ont permis d’expliquer le rôle de chaque source thermique et l'influence de leur combinaison sur la création du bain fondu, l'identification du mode de transfert métallique et la répartition de la chaleur dans la plaque soudée. Les relations entre les signaux électriques et la géométrie de l'arc, les dimensions du bain et la distribution de chaleur sont analysées à différentes échelles de temps. L'analyse thermique présentée montre que l'hypothèse de stationnarité, qui est largement utilisé par les simulateurs, est vraie seulement sur une courte période et pour une longueur donnée de soudure. L’analyse macrographique montre, quant à elle, l'effet de la variation des paramètres d'entrée sur la structure et la géométrie de la soudure.An investigation on hybrid welding physics is presented in the current work. A literature review describes main physical processes occurring during Laser-arc combination and shows main achievements and problematics met during process analysis. Physical processes were studied during joining of very thick materials. Two configurations were used. The first configuration is welding of Superduplex steel in one pass by Laser and arc that are far apart. The second configuration is multipass welding of 18MND5 steel, where defocused Laser beam intercepts arc plasma. With a help of experiment’s design, fast video imaging, electric signals recording, determination of temperature and workpiece distortion, were explained the role of each thermal source and influence of their combination on arc behaviour, molten pool creation, metallic drop transfer evaluation and heat distribution into welded plates. The relationships between electric signals and arc geometry, bath dimensions and heat distribution have been analyzed at various time scales. Thermal analysis, presented in this work, shows that hypothesis of stationarity, which is commonly used in numerical modelling, is true only during a short welding period and for a given weld length. Macrographic analysis shows effect of input parameters variation on weld’s structure and geometry
Génération et analyse des codes graphiques utilisant des motifs texturés pour l'authentification de documents imprimés
No full textDue to the development and availability of printing and scanning devices, the number of forged/counterfeited valuable documents and product packages is increasing. Therefore, different security elements (holograms, inks, papers) have been suggested to prevent these illegal actions. In this thesis, we focus on printed security elements that give access to a high security level with an easy implementation and integration. We present how to generate several novel security elements that aim to protect valuable documents and packaging against unauthorized copying process. Moreover, these security elements allow us to store a huge amount of hidden information.The main characteristic of these security elements is their sensitivity to the print-and-scan process. This sensitivity stems from the use of specific textured patterns. These patterns, which are binary images, have a structure that changes during the printing, scanning and copying processes. We define new specific criteria that ensures the chosen textured patterns to have the appropriate property. The amount of additional information encoded in the patterns increases with the number of patterns used.Additionally, we propose a new weighted mean squared error measure to improve the robustness of module detection for any high density barcodes. Thanks to this measure, the recognition rate of modules used in standard high density barcodes after print-and-scan process can be significantly increased. Finally, we experimentally study several effects: the physical print-and-scan process, separation of scanner noise from printer noise and changes of colors after print-and-scan process. We conclude, from these experimental results, that the print-and-scan process cannot be considered as being a Gaussian process. It has been also highlighted that this process is neither white nor ergodic in the wide sense.En raison du développement et de la disponibilité des appareils d'impression et de numérisation, le nombre de documents contrefaits augmente rapidement. En effet, les documents de valeur ainsi que les emballages de produits sont de plus en plus ciblés par des duplications non autorisées. Par conséquent, différents éléments de sécurité (hologrammes, encres, papiers) ont été proposés pour prévenir ces actions illégales. Dans cette thèse, nous nous concentrons sur les éléments de sécurité imprimés qui offrent un haut niveau de sécurité et qui possèdent une mise en œuvre et une intégration simple. Nous présentons comment générer de nouveaux éléments de sécurité qui visent à protéger les documents de valeur et les emballages contre des processus de duplication non autorisés. Ces éléments nous permettent en outre de stocker une grande quantité d'informations cachées.La caractéristique principale de ces éléments de sécurité est leur sensibilité au processus d'impression et de numérisation. Cette sensibilité est obtenue à l'aide de motifs texturés spécifiques. Ces motifs sont des images binaires qui possèdent une structure sensible aux processus d'impression, de numérisation et de copie. Nous définissons les critères spécifiques qui doivent être respectés lors du choix de ces motifs texturés. La quantité d'information encodée dans l'image augmente avec le nombre de motifs texturés utilisées.En complément, nous proposons dans ce mémoire d'améliorer la robustesse de la détection des modules, pour tous les codes graphiques, par l'utilisation d'une nouvelle mesure d'erreur quadratique moyenne pondérée. L'utilisation de cette nouvelle mesure nous a permis d'augmenter de façon significative le taux de reconnaissance des modules lorsqu'ils sont utilisés dans des codes à barres standard à haute densité. Enfin, nous étudions expérimentalement plusieurs phénomènes : le processus physique d'impression et de numérisation, la séparation du bruit du scanner de celui de l'imprimante et les changements de couleurs après processus d'impression et de numérisation. Nous concluons à partir de cette étude expérimentale, que le processus d'impression et de numérisation ne peut pas être modélisé comme un loi Gaussienne. Nous mettons en avant que ce processus n'est ni blanc ni ergodique au sens large
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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