1,720,986 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
Twin-width : Caractérisations logiques et combinatoires
No full textGraphs consist of vertices connected by edges. They are versatile structures, commonly used to represent networks of transportation, communication, or persons. This versatility comes at a cost: numerous natural algorithmic problems on graphs are hard to solve, for instance finding a largest set of pairwise disconnected vertices. Rather than trying to solve such problems in full generality, one may constrain the input graphs to simplify the problem: for instance, by considering only planar graphs, i.e. the ones drawn in the plane with no crossing edges.This work studies such a constraint: twin-width, introduced in 2020 by Bonnet, Kim, Thomassé, and Watrigant. Graphs with small twin-width—which for instance include planar graphs—are simple in many ways: they admit efficient algorithms for any problem expressed in first-order logic; and there are relatively few of them: only a single exponential number.Are these two properties exclusive to graphs of small twin-width? In general they are not: there are known graphs with large twin-width which are simple for first-order logic, and this work constructs a class with few graphs but large twin-width. This however changes when considering twin-width other than graphs: twin-width is known to be equivalent to the former two conditions in ordered graphs and permutations, and we extend this result to tournaments. These three kinds of structure also allow efficient approximation algorithms for twin-width, an open problem in general graphs.Un graphe est composé de sommets connectés par des arêtes : c’est une structure versatile, utilisée couramment pour représenter des réseaux de transports, de communication, ou d'individus. Cette versatilité a un prix : beaucoup de problèmes naturels — e.g. trouver un nombre maximum de sommets sans aucune connexion — sont difficiles. Plutôt qu’essayer de les résoudre en toute généralité, on peut imposer des contraintes sur les graphes pour faciliter la tâche : par exemple, se restreindre aux graphes planaires, i.e. pouvant être dessinés sur le plan sans croisement. C'est dans cet esprit que Bonnet, Kim, Thomassé et Watrigant ont introduit en 2020 la twin-width. Les graphes dont la twin-width est petite — par exemple, les graphes planaires — sont simples de multiples façons : notamment, ont peut efficacement y résoudre tout problème de logique du premier ordre, et il y en a peu, un nombre simplement exponentiel en le nombre de sommets. Ces propriétés remarquables sont elles vérifiées seulement quand twin-width est petite ? En général, c’est faux : on connaît des graphes de grande twin-width simples pour la logique du premier ordre, et cette thèse construit une classe avec peu de graphes mais grande twin-width. Mais la situation change lorsque l’on étend la twin-width à des structures autres que les graphes : dans les graphes ordonnés et les permutations, l’équivalence entre petite twin-width et ces conditions est connue, et l’on généralise cela aux tournois. Pour ces mêmes structures, on peut rapidement approximer la twin-width, un problème ouvert en général
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
Twin-Width, logical and combinatorial characterisations
No full textUn graphe est composé de sommets connectés par des arêtes : c’est une structure versatile, utilisée couramment pour représenter des réseaux de transports, de communication, ou d'individus. Cette versatilité a un prix : beaucoup de problèmes naturels — e.g. trouver un nombre maximum de sommets sans aucune connexion — sont difficiles. Plutôt qu’essayer de les résoudre en toute généralité, on peut imposer des contraintes sur les graphes pour faciliter la tâche : par exemple, se restreindre aux graphes planaires, i.e. pouvant être dessinés sur le plan sans croisement. C'est dans cet esprit que Bonnet, Kim, Thomassé et Watrigant ont introduit en 2020 la twin-width. Les graphes dont la twin-width est petite — par exemple, les graphes planaires — sont simples de multiples façons : notamment, ont peut efficacement y résoudre tout problème de logique du premier ordre, et il y en a peu, un nombre simplement exponentiel en le nombre de sommets. Ces propriétés remarquables sont elles vérifiées seulement quand twin-width est petite ? En général, c’est faux : on connaît des graphes de grande twin-width simples pour la logique du premier ordre, et cette thèse construit une classe avec peu de graphes mais grande twin-width. Mais la situation change lorsque l’on étend la twin-width à des structures autres que les graphes : dans les graphes ordonnés et les permutations, l’équivalence entre petite twin-width et ces conditions est connue, et l’on généralise cela aux tournois. Pour ces mêmes structures, on peut rapidement approximer la twin-width, un problème ouvert en général.Graphs consist of vertices connected by edges. They are versatile structures, commonly used to represent networks of transportation, communication, or persons. This versatility comes at a cost: numerous natural algorithmic problems on graphs are hard to solve, for instance finding a largest set of pairwise disconnected vertices. Rather than trying to solve such problems in full generality, one may constrain the input graphs to simplify the problem: for instance, by considering only planar graphs, i.e. the ones drawn in the plane with no crossing edges.This work studies such a constraint: twin-width, introduced in 2020 by Bonnet, Kim, Thomassé, and Watrigant. Graphs with small twin-width—which for instance include planar graphs—are simple in many ways: they admit efficient algorithms for any problem expressed in first-order logic; and there are relatively few of them: only a single exponential number.Are these two properties exclusive to graphs of small twin-width? In general they are not: there are known graphs with large twin-width which are simple for first-order logic, and this work constructs a class with few graphs but large twin-width. This however changes when considering twin-width other than graphs: twin-width is known to be equivalent to the former two conditions in ordered graphs and permutations, and we extend this result to tournaments. These three kinds of structure also allow efficient approximation algorithms for twin-width, an open problem in general graphs
Twin-width : Caractérisations logiques et combinatoires
No full textGraphs consist of vertices connected by edges. They are versatile structures, commonly used to represent networks of transportation, communication, or persons. This versatility comes at a cost: numerous natural algorithmic problems on graphs are hard to solve, for instance finding a largest set of pairwise disconnected vertices. Rather than trying to solve such problems in full generality, one may constrain the input graphs to simplify the problem: for instance, by considering only planar graphs, i.e. the ones drawn in the plane with no crossing edges.This work studies such a constraint: twin-width, introduced in 2020 by Bonnet, Kim, Thomassé, and Watrigant. Graphs with small twin-width—which for instance include planar graphs—are simple in many ways: they admit efficient algorithms for any problem expressed in first-order logic; and there are relatively few of them: only a single exponential number.Are these two properties exclusive to graphs of small twin-width? In general they are not: there are known graphs with large twin-width which are simple for first-order logic, and this work constructs a class with few graphs but large twin-width. This however changes when considering twin-width other than graphs: twin-width is known to be equivalent to the former two conditions in ordered graphs and permutations, and we extend this result to tournaments. These three kinds of structure also allow efficient approximation algorithms for twin-width, an open problem in general graphs.Un graphe est composé de sommets connectés par des arêtes : c’est une structure versatile, utilisée couramment pour représenter des réseaux de transports, de communication, ou d'individus. Cette versatilité a un prix : beaucoup de problèmes naturels — e.g. trouver un nombre maximum de sommets sans aucune connexion — sont difficiles. Plutôt qu’essayer de les résoudre en toute généralité, on peut imposer des contraintes sur les graphes pour faciliter la tâche : par exemple, se restreindre aux graphes planaires, i.e. pouvant être dessinés sur le plan sans croisement. C'est dans cet esprit que Bonnet, Kim, Thomassé et Watrigant ont introduit en 2020 la twin-width. Les graphes dont la twin-width est petite — par exemple, les graphes planaires — sont simples de multiples façons : notamment, ont peut efficacement y résoudre tout problème de logique du premier ordre, et il y en a peu, un nombre simplement exponentiel en le nombre de sommets. Ces propriétés remarquables sont elles vérifiées seulement quand twin-width est petite ? En général, c’est faux : on connaît des graphes de grande twin-width simples pour la logique du premier ordre, et cette thèse construit une classe avec peu de graphes mais grande twin-width. Mais la situation change lorsque l’on étend la twin-width à des structures autres que les graphes : dans les graphes ordonnés et les permutations, l’équivalence entre petite twin-width et ces conditions est connue, et l’on généralise cela aux tournois. Pour ces mêmes structures, on peut rapidement approximer la twin-width, un problème ouvert en général
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