1,721,110 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
Study of the hydro-sedimentary dynamics of tropical rivers by measures in situ and remote sensing : the case of the Maroni, Oyapock and Orinoco
No full textL'eau des fleuves, des rivières, des lacs et des réservoirs ne représente que 0,26 % des 2,5 % (35 millions de km3) d'eau douce disponibles à l’état liquide sur Terre, or sa qualité et quantité ont fortement diminué ces dernières années. Sa dégradation a des conséquences sur l'agriculture, la santé, l'environnement et l'économie des territoires et est aujourd'hui au centre des préoccupations sociétales. Les objectifs de la présente thèse sont pour trois fleuves localisés dans le Bouclier des Guyanes, au nord de l'Amérique du Sud (le Maroni, l'Oyapock, l'Orénoque): (i) d'utiliser et d'adapter des outils novateurs de télédétection pour suivre et quantifier, sur du long terme, leurs charges sédimentaires en suspension, (ii) d'évaluer l'existence de tendances spatio-temporelles, ainsi que de ruptures dans les chroniques de données, (iii) de quantifier la part organique et minérale de ces charges, (iv) d'apprécier le rôle des facteurs naturels (débits et précipitations) et anthropiques (surfaces urbaines, agricoles et minières) sur les tendances observées et enfin, (v) de discuter de seuils de charges pour le suivi de la qualité de l'eau. Les résultats ont montré qu'il est possible de suivre les concentrations de matières en suspension, pour les fleuves Orénoque et Maroni avec une erreur relative de 32 et 25% respectivement. Sur la période 2000-2016, des tendances spatio-temporelles régulières ont été observées pour l'Orénoque, alors qu'elles sont en augmentation pour le Maroni avec une rupture en 2009 et en diminution pour l'Oyapock depuis 2008 (données in situ). Un lien fort avec l'augmentation de la déforestation pour les surfaces minières et les précipitations est observé pour le Maroni alors que pour l'Oyapock les tendances sont liées aux débits.Pour les deux années d'études (2014-2016), les charges minérales ont représenté la plus forte fraction des particules transportées dans les eaux du Maroni au Saut Hermina (en moyenne 93 %) et de l'Oyapock au Saut Maripa (en moyenne 82 %) avec une grande variabilité selon les mois de la teneur en carbone dans les matières transportées et pour les deux fleuves. Enfin, les rapports C/N et C/Chl-a ont dévoilé des matières organiques d'origine principalement endogène avec une forte biomasse chlorophyllienne surtout durant les basses eaux.The water of rivers, lakes and reservoirs represents only 0.26 % of the 2.5 % (35 million of km3) of fresh water available on the liquid state on Earth, but its quality and quantity strongly decreased these last years. Her degradation has consequences on the farming, the health, the environment and the economy of territories and is now in the center of the societal concerns. The objectives of the present thesis are for three rivers located in the Guiana Shield, in the North of South America (the Maroni, the Oyapock, the Orinoco): i) to use and to adapt innovative tools of remote detection to follow and quantify, on the long term, their sedimentary loads, ii) to estimate the existence of spatiotemporal trends, as well as breaks in the chronicles of data, iii) to quantify the organic and mineral part of these loads, iv) to appreciate the role of the natural (discharge and precipitation) and the anthropological factors (urban, agricultural and mining surfaces) on the observed trends and finally, v) to discuss thresholds of concentrations for the quality monitoring of the river water.The results showed that it is possible to follow the concentrations of suspension materials, for rivers Maroni and Orinoco with a relative error of 25 and 32 % respectively. Over the period 2000-2016, regular spatiotemporal trends were observed for the Orinoco, while they are increasing for Maroni with a break in 2009 and in decrease for the Oyapock since 2008 (in situ data). A strong link with the increase of the deforestation for the mining surfaces and the precipitation is observed for the Maroni catchment while for the Oyapock the trend is explained by the specific water discharge.For two years of studies (2014-2016), the mineral loads represented the strongest fraction of particles transported in the Maroni River at Saut Hermina (on average 93 %) and in the Oyapock River at Saut Maripa (on average 82 %) with a high variability according to the months of the content in carbon in the transported materials and for both rivers. Finally, report C/N and C/Chl-a revealed organic matters of mainly endogenous origin with a strong chlorophyll biomass and especially during the low water period
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
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
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