Le répertoire des figures

Balzac ne cesse de rattacher ses personnages aux grandes figures du passé, de celles qui sont recueillies dans ces répertoires biographiques que goûte tant la librairie romantique (ainsi de la Biographie Michaud). Les appositions (« Troubert, l’Alexandre VI de Tours »), les antonomases (« une nouvelle Diane de Poitiers »), les listes exemplaires et autres opérateurs analogiques inscrivent les personnages balzaciens dans un jeu dynamique de liaisons, d’apparentements, comme s’il s’agissait de leur donner une légitimité qui leur ferait défaut. Ces traits stylistiques nous disent quelque chose du personnage de roman, de son statut, de la légitimité fragile qui est la sienne au regard des personnages de la fable, des figures héritées de la tradition : sa présence incertaine dans nos mémoires est toujours près d’être dénoncée comme une usurpation.Balzac consistently connects his characters to important figures of the past, like those that are collected in the biographical catalogues that were so appreciated by the Romantic library (such as the Biographie Michaud). Appositions (“Troubert, l’Alexandre VI de Tours”), antonomasia (“une nouvelle Diane de Poitiers”), exemplary lists and other analogical operators place Balzac’s characters in a network of liaisons and affiliations, as if it were a matter of giving them a legitimacy which would be their shortcoming. These stylistic traits reveal something about the character in the novel, about his status, and his fragile legitimacy in relation to the characters of the fable and the inherited figures of tradition. His uncertain presence in our memory is always close to being denounced as usurpation

Algorithms for the Multiclass Network Equilibrium Problem

International audienceWe consider a nonatomic congestion game on a connected graph, with several classes of players. Each player wants to go from its origin vertex to its destination vertex at the minimum cost and all players of a given class share the same characteristics: cost functions on each arc, and origin-destination pair. In the transportation terminology, each class models a distinct mode of transportation, such as cars, trucks, or motorbikes for example.A strategy profile is a mapping determining for each player a route from its origin to its destination. A strategy profile is a (pure) Nash equilibrium if no player would benefit by changing its route. This game enters in the category of nonatomic congestion games with player-specific cost functions, see Milchtaich (Congestion games with player-specific payoff functions, Games Econom. Behavior, 13:111-124, 1996). The problem of finding a Nash equilibrium for such a game is called the Multiclass Network Equilibrium Problem. Under some mild conditions, it is known that a Nash equilibrium exists, but the computation of an equilibrium in the multiclass case is an open problem for general functions. We consider the specific case where the cost functions are affine and stricly increasing. In this case, we write the Multiclass Network Equilibrium Problem as a linear complementarity problem. Our contribution is twofold: - We prove the existence of a polynomial algorithm solving the problem when the graph consists in parallel arcs. The main idea of the algorithm relies on properties of hyperplane arrangements.- We build a pivoting algorithm, adapted from Lemke (Bimatrix equilibrium points and equilibrium programming, Management Science, 11:681-689, 1965), solving the problem for general graphs. To our knowledge, it is the first algorithm solving this problem. We prove its efficiency through computational experiments. Moreover, this algorithm provides the first constructive proof of the existence of an equilibrium for this problem.</p

A Lemke-like algorithm for the Multiclass Network Equilibrium Problem

14 pagesWe consider a nonatomic congestion game on a connected graph, with several classes of players. Each player wants to go from its origin vertex to its destination vertex at the minimum cost and all players of a given class share the same characteristics: cost functions on each arc, and origin-destination pair. Under some mild conditions, it is known that a Nash equilibrium exists, but the computation of an equilibrium in the multiclass case is an open problem for general functions. We consider the specific case where the cost functions are affine and propose an extension of Lemke's algorithm able to solve this problem. At the same time, it provides a constructive proof of the existence of an equilibrium in this case

Avant-Propos

International audienceLes articles rassemblés dans ce numéro se penchent davantage sur les phénomènes explicites de mémoire que de démémoire ou d'oubli. Mais qu'il s'agisse du genre littéraire des mémoires (A. Coudreuse), des proverbes et de la parémie en général (G. Achard-Bayle et B. Schneider), des tropes de la mémoire textuelle (S. Lawson) ou des désignants d'événements (L. Calabrese), toute mémoire discursive et textuelle, qui s'inscrit dans les mots et les discours, procède par oubli de ce qui ne sera pas elle. Comme le montrent G. Cislaru et F. Rakotoelina, le processus de la mémoire est complexe et hétérogène, activant tout en même temps plusieurs fonctions cognitives, comme le langage, l'émotion et l'organisation expérientielle, qui s'articulent elles-mêmes avec les données culturelles, sociales et historiques

Isabelle Daunais, Les Grandes Disparitions. Essai sur la mémoire du romanIsabelle Daunais, Des ponts dans la brume

En 2008, Isabelle Daunais a fait paraître deux livres, l’un aux Presses universitaires de Vincennes, l’autre aux Éditions du Boréal, qu’il est extrêmement instructif de lire conjointement, ce que très peu de lecteurs sans doute ont eu l’occasion de faire, étant donné l’obstination que mettent les milieux éditoriaux français et québécois à s’ignorer mutuellement. Le premier est un essai qui énonce et déplie en trois chapitres d’une quarantaine de pages chacun, dans une prose tendue, riche en f..

Teaching of Statistics in Social Sciences Through E-Learning

International audienceThis paper focuses on the organization and content of social interactions in a group of University of Lyon 2 students engaged in an e-learning situation dealing with statistical concepts. The importance of social interactions in the teaching and learning has been informed by socio-constructivist theories. We examined observable traces of micro-level exchanges between students engaged in a complex e-learning task, noting technical constraints and spatio-temporal characteristics that influence course participants engaged in a social organization established to achieve a common goal. To do this we used both quantitative and qualitative analyses of messages exchanged on a participant discussion forum. Statistics education in an online, distance, collaborative group situation is a new framework for learning. The mechanism of teaching and learning based on collaborative work through the observable traces of online social interactions was explored. The main focus of our study was to discover what occurs when students attempt to learn Statistics without face-to-face meetings with their classmates and their teacher. Our data show that in this online course, students took keen interest in the topic and enhanced their learning. We believe that this online mode of teaching statistics, even though lacking in face-to-face interactions, should be implemented on a wider scale since it has the potential to provide more opportunities for interactions irrespective of geographical boundaries

Editorial

Cette première livraison des Études platoniciennes doit inaugurer une série de volumes annuels : une fois l’an, plusieurs études seront ainsi rassemblées, parfois autour d’un thème ou d’un ouvrage, pour contribuer à la connaissance de l’œuvre et de la postérité platoniciennes. Si ces études platoniciennes portent d’abord sur les dialogues de Platon, elles entendent toutefois montrer une attention toute particulière à la tradition platonicienne ancienne, aux différentes œuvres comme aux différ..