1,721,144 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
Optimisation and simulation of a rail-road transportation service in sparsely populated area
No full textLes travaux de cette thèse visent à concevoir les algorithmes d’exploitation d’une flotte constituée de véhicules rail-route de 14 places amenés à redynamiser le transport ferroviaire dans les zones peu denses. Deux systèmes d’exploitation sont étudiés dans nos travaux : un transport à la demande en porte à porte très souple d’utilisation pour les usagers, et la conception de lignes horairisées plus faciles à mettre en œuvre.Nos travaux se sont concentrés sur le développement et l'étude d'algorithmes d'exploitation pour ces deux systèmes de transports afin de bénéficier de la souplesse offerte par la route, et de la mobilité apportée par le réseau ferré tout en respectant les contraintes spécifiques au monde ferroviaire.Nous présentons une modélisation mathématique afin de définir le problème de transport à la demande avec contraintes ferroviaires, puis une méthode heuristique de résolution pour introduire facilement les contraintes ferroviaires et concevoir une solution pour des clients ayant réservé. Cette méthode est ensuite adaptée afin d’intégrer des clients à la volée et d’ajuster dynamiquement les trajets des véhicules.Nous définissons et présentons le problème de conception de ligne de transport horairisée construite autour d’une voie ferrée que nous évaluons à l’aide de critères issus de la littérature et du monde ferroviaire.Enfin, nous intégrons les algorithmes de transport à la demande dans un simulateur afin d’évaluer précisément, et avec les conditions les plus réalistes possibles, les performances d’un tel système sur le territoire cible. Nous présentons aussi une comparaison des performances des deux systèmes de transport sur le territoire choisi par SNCF.The aim of this work is to design the operating algorithms for a fleet of 14-seaters rail-road vehicles, used to revive train lines in sparsely populated area. Two operating systems have been studied in our work: a door-to-door on-demand transportation system offering a great flexibility to users, while the second is easy to implement for the operator and is based on the design of timetabled lines.Our work has therefore focused on the study of these two transport systems and the development of operational algorithms that can consider the flexibility offered by road transport and the mobility offered by the rail network, while respecting the constraints specific to the rail world.We present a mathematical model to define the Dial-A-Ride problem with Railway Constraints, then we present a heuristic solution method to introduce easily railway constraints when designing a transport plan for customers who have booked. This method is adapted to include customers on the fly and to adjust vehicle routes to best serve these new customers. The performance of each method is evaluated using indicators from the literature as well as indicators dedicated to this new vehicle.We define and present the problem of designing timetabled services around a railway line that serves as the backbone of the service. Performance is then evaluated using criteria from the literature and adapted to a rail-road service.We integrate the on-demand transport algorithms into a simulator to evaluate precisely and under realistic conditions the performance of such a system in the target area. We also present a comparison of the performance of the two transport systems in the area chosen by SNCF
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
Models and methods for capacitated lot-sizing problems
No full textInternational audienceThis is a summary of the author's PhD thesis supervised by Philippe Chrétienne and Safia Kedad-Sidhoum and defended in December 2005 at the Université Pierre et Marie Curie (Paris VI). The thesis is written in French and is available from http://absi.nabil.free.fr/ABSI-Thesis.pdf. This work mainly deals with multi-item capacitated lot-sizing problems with setup times, shortages on demand and safety stock deficit costs. We propose a new mathematical model that includes these new constraints. Three solution approaches are considered: branch-and-cut, Lagran-gean relaxation and MIP-based heuristics approaches. Experimental results showing the effectiveness and the limit of each approach are presented
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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