Keynote Speakers

François Baccelli

François Baccelli has been appointed as Adviser to the Technology Transfer and Innovation Department for national actions and industrial partnerships in the fied of telecommunication, on 1st june 2007. Member of the Academy of Sciences and Research Director at INRIA. He is the French specialist in stochastic network modelling. A former student of ENST, he published his thesis in 1980 on the subject "Queues with Failures and Applications in Modelling Information Technology Systems" at Orsay, and then his doctorate in 1983, "Probabilistic Models of Distributed Systems", while beginning a research career at INRIA. He works with Pierre Brémaud on queue network analysis using stationary point processes, as detailed in the books "Palm probabilities and stationary queues" and "Elements of Queuing Theory" published by Springer Verlag in 1987 and 1994. François Baccelli participated with Guy Cohen, Jean-Pierre Quadrat and Geert Jan Olsder in developing max-plus algebra in the book, Synchronization and Linearity, published by Wiley in 1992. He is totally convinced that this theory can be applied to large-scale systems and supports creation of a European research community and software development in this field. He has been working for several years on developing mathematical models to control data transfer, in cooperation with Alcatel on satellite networks and then ADSL networks. This research has had a major impact in terms of opening up new fundamental directions and creating innovative technology to control communication networks. The French contributions of François Baccelli and the group that he formed in Sophia-Antipolis are among the rare European contributions that regularly appear in the best reputed conferences in the field. His publications (more than 80 articles in journals, 3 books, a dozen patents) have received broad attention in the media and he is frequently invited to the most widely renown international conferences. In a recent article, he gives a quite new and in-depth interpretation of TCP protocol dynamics, providing insight that is useful in practice, which has motivated the creation of the start-up company N2NSoft. He is currently working alongside B. Blaszczyszyn to develop a new avenue of research on radio-mobile network analysis using random geometric methods. He taught from 1990 to 2001 in the department of applied mathematics at the Ecole Polytechnique. He holds four prizes, among which the France Telecom Prize, which was attributed to him by the Academy of Sciences in 2002. Today, François Baccelli is the scientific head of the TREC project-team, run jointly by INRIA (Rocquencourt) and ENS-Ulm, within the Ecole Normale Supérieure, which enjoys scientific recognition at the highest world level and maintains vital privileged industrial relations with ATT Labs, Sprint, Microsoft Research, Intel, Alcatel, France Telecom and Thomson.

Keynote title: "Stochastic Geometry and Wireless Communications".

Sergiu Hart

Sergiu Hart is the Kusiel-Vorreuter University Professor, Professor of Mathematics, and Professor of Economics at the Hebrew University of Jerusalem. His previous academic appointments were at Stanford University, Tel Aviv University, and Harvard University. From 1991 to 1998 Sergiu Hart was the Founding Director of the Center for the Study of Rationality, a world-leading multidisciplinary research center at the Hebrew University of Jerusalem; he is currently the Chair of its Academic Committee. Sergiu Hart was elected Fellow of the Econometric Society in 1985, and Member of the Israel Academy of Sciences and Humanities in 2006. In 1998 he received the Rothschild Prize. He was selected to deliver the Cowles Lecture at Yale University in 2000, the Walras-Bowley Lecture of the Econometric Society in 2003, and the Harris Lecture at Harvard University in 2009. Sergiu Hart has served as the President of the Israel Mathematical Union in 2005 and 2006, and is currently the President of the Game Theory Society. The main area of research of Sergiu Hart is game theory and economic theory, with additional contributions in mathematics, computer science, probability and statistics.

Keynote title:  "Dynamics and Equilibria: A Game-Theoretic Perspective"

An overview of some recent work on dynamical systems in multi-player environments: On the one hand, there are simple adaptive heuristics -- such as "regret matching" -- that lead in the long run to correlated equilibria, a concept that embodies full rationality. On the other hand, the natural informational restriction that each participant does not know the payoff functions of the other participants -- "uncoupledness" -- severely limits the possibilities to converge to Nash equilibria. Connections to behavioral economics, neurobiological studies, and cognitive radio, will also be mentioned.
 

Romualdo Pastor-Satorras

Romualdo Pastor-Satorras received is PhD in Statistical Physics at the University of Barcelona in 1990. He has been a research fellow at Yale University and at the Massachusetts Institute of Technology. He spent two years as a research fellow at the International Centre for Theoretical Physics (UNESCO) in Trieste, Italy, and then moved back to Spain in 2000 as Assistant Professor at the University of Barcelona. In 2001 he joined the Universitat Politecnica de Catalunya, first as a Ramon y Cajal fellow and at present as Associate Professor. He is the author of more than 60 research papers in international journal and has written the book "Evolution and Structure of the Internet: A Statistical Physics Approach" (Cambridge University Press, Cambridge, 2004) in collaboration with A. Vespignani. He has been awarded the prizes "Distincio de la Generalitat per a la Promocio de la Recerca for young researchers" (2003) and the ICREA Academia prize (2008)

Keynote title: "An introduction to the theory of Complex Networks"

The sociological experiments performed by S. Milgram in the 60's illustrated that we live in a "small world"; that is, in the social network formed by people related by friendship relations, we are separated by a short chain of acquitances from any individual. Recently, it has been proved that, in fact, not only social systems, but a large variety of natural and artifical systems can be fruitfully represented and studied as "complex networks" of interacting units. Apart from social networks, we can cite as examples of this kind of systems metabolic reactions in cells, protein interactions, ecosystems, networks of transport of people, energy or goods, the World-Wide Web, the Internet, etc. The theory of complex networks allows to describe and understand the structural properties of these complex systems, as well as elucidate the profound impact that their structure has on their function. In this talk we will present an introduction to the description of real complex systems in terms of complex networks. The potential applications of this formalism will be shown with examples ranging from new strategies for the design of efficient medicines to the rationalization of the behavior of computer viruses.

Patrick Thiran

Patrick Thiran is an associate professor at EPFL. He received the electrical engineering degree from the Université Catholique de Louvain, Louvain-la-Neuve, Belgium, in 1989, the M.S. degree in electrical engineering from the University of California at Berkeley, USA, in 1990, and the PhD degree from EPFL, Switzerland, in 1996. He became an adjunct professor in 1998, an assistant professor in 2002 and an associate professor in 2006. From 2000 to 2001, he was with Sprint Advanced Technology Labs, Burlingame, CA, and in 2008 with Nokia Research, Helsinki. His research interests include communication networks, performance analysis, dynamical systems and stochastic models. He is currently active in the analysis and design of wireless multi-hop networks and in network monitoring. He served as an associate editor for the IEEE Transactions on Circuits and Systems in 1997-99, and he is currently an associate editor for the IEEE/ACM Transactions on Networking since 2006. He also served on the program committee of different conferences in networking, including Sigcomm, Sigmetrics, Mobihoc and Infocom. He was the recipient of the 1996 EPFL Ph.D. award, and of the 2008 Crédit Suisse Teaching Award.

Keynote title: "Phase transitions in large wireless multi-hop networks"

Large scale concepts, and in particular phase transitions, have always been factored in the analysis of natural systems, such as large ensembles of atoms and molecules. This is more recent in the context of man-made systems, such as wireless multi-hop networks. Like spin glasses in Physics, these networks are governed by phase transitions: a small change in one variable (which is here, the transmitting power, or the channel access attempt rate) has a dramatic effect on the properties of the whole network (connectivity, throughput, fairness). We will see two examples of such phase transitions, and discuss their implications on the performance of the network. We will first see how percolation theory enables us to study the transport capacity of a wireless multihop network. Requiring all nodes of to be connected is expensive and results in a poor scalability. It is no longer the case if we only slightly loosen the connectivity requirement, by just imposing that most nodes be connected to each other, thanks to the emergence of a giant cluster connecting most nodes. Exploiting this phase transition is a key ingredient in getting tight bounds on transport capacity. Next, we explore the fundamental trade-off that exists between high spatial reuse (or throughput) and fairness, which is inherent to decentralized CSMA/CA MAC protocols such as IEEE 802.11. We show in particular that the widely observed unfairness of the protocol in small network topologies does not always persist in large topologies. In large 1-dim. networks, nodes sufficiently far away from the border of the network have equal access to the channel, but not in 2-dim networks, where we observe a phase transition, linked to the existence of multiple Gibbs measures in the Markov Random Field model.
This is a joint work with Mathilde Durvy and Olivier Dousse.