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Publication in TCS: On MultiAspect graphs

by Klaus Wehmuth, , Éric Fleury, , Artur Ziviani,



Different graph generalizations have been recently used in an ad-hoc manner to represent multilayer networks, i.e. systems formed by distinct layers where each layer can be seen as a network. Similar constructions have also been used to represent time-varying networks. We introduce the concept of MultiAspect Graph (MAG) as a graph generalization that we prove to be isomorphic to a directed graph, and also capable of representing all previous generalizations. In our proposal, the set of vertices, layers, time instants, or any other independent features are considered as an aspect of the MAG. For instance, a MAG is able to represent multilayer or time-varying networks, while both concepts can also be combined to represent a multilayer time-varying network and even other higher-order networks. Since the MAG structure admits an arbitrary (finite) number of aspects, it hence introduces a powerful modelling abstraction for networked complex systems. This paper formalizes the concept of MAG and derives theoretical results useful in the analysis of complex networked systems modelled using the proposed MAG abstraction. We also present an overview of the MAG applicability.


Graph generalization; Multilayer networks; Time-varying graphs; Higher-order networks; Complex networks; Network science


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ANR – SoSweet : A sociolinguistics of Twitter — social links and linguistic variations

The SoSweet project focuses on the synchronic variation and the diachronic evolution of the variety of French language used on Twitter.
The Web has entered all areas of our social life. As the language is central in our social interactions, it is legitimate to ask how the Web has become a factor acting on language. This is even more actual as the recent rise of novel digital services opens up new areas of expression, which support new linguistics behaviors. In particular, social medias such as Twitter provide channels of communication through which speakers/writers use their language in ways that differ from standard written and oral forms. The result is the emergence of new varieties of languages.

A characteristic of these varieties is that they exhibit large variability among communities of speakers and high innovation rates. A scientific description must take into account this variability and explain how social forces and technical constraints regulate its dynamic. The main goal of SoSweet is to provide a detailed account of the links between linguistic variation and social structure in Twitter, both synchronically and diachronically. Through this specific example, and aware of its bias, we aim at providing a more detailed understanding of the dynamic links between individuals, social structure and language variation and change.

Traditional methods are not suitable to address these questions. On the one hand, Twitter requires redefining fundamental concepts such as “addressee” or the public/private communication distinction. Moreover, while sociolinguistic studies are based on small samples, we will base our analysis on a corpus of 500 million tweets combined with the social network of the 10 million users who authored these tweets, complemented by socio-demographic data. This large data mass leads us to heavily rely on computational methods from different areas. The SoSweet project will therefore adopt a strong interdisciplinary position, at the crossing of social media linguistics, sociolinguistics, natural language processing (NLP) and network science.

The NLP tools are designed for standard forms of language and exhibit a drastic loss of accuracy when applied to social media varieties. To define appropriate tools, descriptions of these varieties are needed. Descriptions that needs tools. We will address this circularity interdisciplinary, by working simultaneously both on linguistics description and on NLP tools development. For its part, network science provides us with tools for studying massive data from complex networks of users, through graph theory and computational modeling.

The scientific program of SoSweet has been conceived in order to favor optimal interdisciplinary work as the four work packages (management, data collection and enrichment, variation and evolution analysis, outreach) involve all partners. The project will last 48 months. It involves 4 leading teams in their own field of research. The principal investigator, Icar, is specialized in corpus linguistics and computer mediated interaction. Icar will carry out the tasks of unifying linguistics evidences (empirical and theoric) with social clues (extracted from a massive network of sociological relations). Lidilem is in charge of adapting the sociolinguistics framework to the case of variation and communication on Twitter. Alpage, specialized in natural language processing, takes care of the linguistics enrichment part, which provides the other partners with normalized and structurally enriched forms of text. Alpage is also responsible of providing distributional analysis of our corpus, by the means of various forms of word clustering in order to define sociolinguistic variants in the tweets. Inria DANTE, specialized in the exploration of massive graph structures, will lead the crucial network analysis and will work on jointly integrating the sociological network and the linguistic distributional network of lexical relations


Publication by Yannick: Call Detail Records to Characterize Usages and Mobility Events of Phone Users


We analyze a very large Call Detail Records (CDR) over 12 months in Mexico. It contains 8 millions users ans 5 billions of call events. Our first contribution is the study call duration and inter-arrival time parameters. Then, we assess user movements between consecutive calls (switching from a station to another one). Our study suggests that user mobility is pretty dependent on user activity. Furthermore, we show properties of the inter-call mobility by making a analysis of the call distribution

SOCIONET: 6-8 Juin 2016 / ENS de Lyon

Rencontres interdisciplinaires pour jeunes chercheurs sur les réseaux sociaux : description, données, modélisation, interprétation


L’Institut rhônalpin des systèmes complexes organise les 6-8 juin un atelier thématique de trois jours sur la notion de réseau social, ses usages dans différentes disciplines et sur les données qui la documentent. Par réseau, nous désignons un ensemble d’unités sociales interconnectées, qui peuvent être des individus, des collectifs informels, des institutions, et qui sont reliés par différents types de liens (amitié, commerce, contacts via les média sociaux numériques, fréquentation des mêmes associations, etc.).

L’objectif de l’atelier est de favoriser les échanges interdisciplinaires entre des champs qui décrivent, modélisent, interprètent le fonctionnement des réseaux sociaux, qu’il s’agisse de secteurs des Sciences humaines et sociales (SHS) ou de secteurs des Sciences et technologies de l’information et de la communication (STIC).

Cet atelier offre une tribune aux doctorant(e)s et postdoctorant(e)s qui souhaitent présenter leurs travaux sur les réseaux sociaux et les mettre en perspective grâce à l’échange interdisciplinaire. Les présentations proposées par les jeunes chercheurs alterneront avec les interventions de chercheurs plus avancés dont le rôle est de structurer les échanges interdisciplinaires en présentant la mise en oeuvre de la notion de réseau dans de larges domaines (Sciences des réseaux et Sociologie) ou sur des points particuliers.

Les deux jours de présentation des travaux (7 et 8 juin) seront précédés par un concours baptisé Datathon (6 juin). Il mobilisera des équipes de trois ou quatre étudiant(e)s de niveau L3, M1 ou M2, incluant nécessairement un membre des sciences humaines et sociales et un membre d’un parcours d’informatique. Il leur sera remis un jeu de données à analyser et interpréter. Un jury interdisciplinaire sélectionnera l’équipe lauréate, qui recevra un prix et présentera son travail lors l’atelier des 7 et 8 juin.

(Français) La Lambretta

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