September 21th, 2016

  • 10:00 - M.A. Aziz-Alaoui, C. Bertelle (LMAH, LITIS, Normandie Univ, UNIHAVRE, France)
  • 10:10 - Paul Bourgine (Ecole polytechnique & CS-DC UNESCO UniTwin, Paris, France)
    • Toward an Integrative Logistics in the CS-DC TIMES flagship

      The talk is presenting what could be an Integrative Logistics, as a new integrative and predictive science, in the framework of the CS-DC TIMES flagship. This flagship aims at creating a global e-ecosystem to give the same equality of chance for any territory to become a "smart" territory by using a global market for open responsible innovations linked to the global scientific and technological revolution. This global e-ecosystem is using the 2nd internet revolution for sharing in a trustable way the big data including the ones tracing the current logistic activities between territories at all levels. The main challenge of Integrative Logistics is, through dynamical deep learning, to bring multilevel logistic models toward a "smart" multilevel logistics. Such goal has to involve all of these - scientists of any discipline or experts from territorial governments, NGOs, firms, start-ups as well as ordinary citizens - wanting to jointly increase social wellbeing, improve the relationship with Nature and to change the relations between science, engineering, politics and ethics.

      Paul Bourgine is President of the Complex Systems Digital Campus (CS-DC), honorary director of RNSC (the French National Network of Complex Systems) and former director of CREA-Ecole Polytechnique. Diploma of Ecole Polytechnique (1968), PhD in Economics (1983), habilitation in cognitive science (1989). First president of the Complex Systems Society. Chair of the first European Conference on Complex Systems (2005) and World e-Conference CS-DC'15 (2015). Co-chair of the first following international conferences: Economics and Artificial Intelligence (1986), European Conference on Artificial Life (1990), Cognitive Economics (2004), Morphogenesis in Living Systems (2009).

  • 10:35 - Valentina Lanza (LMAH, Normandie Univ, UNIHAVRE, France)
    • Coupling effects and bifurcations in network of bistable dynamical systems

      Oscillatory networks have been one of the most used paradigms in order to mimic repetitive dynamical processes taking place in complex systems. The leading feature of oscillatory networks is the emergence of synchronized oscillations among their elements, i.e. it is observed that quite a lot of oscillators tune their rhythms so that numerous groups of them exhibit highly correlated behavior. From a mathematical point of view, the emergence of such coordinated behavior corresponds to the existence of global periodic oscillations, that can arise, for example, through Hopf bifurcations. Understanding how the interactions among the oscillators influence the appearance of properties such as global oscillations may be crucial in order to characterize complex dynamics in oscillatory networks. Moreover, it is well known in literature that in case of multistability in a single element of the network, new equilibrium configurations arise due to the coupling. In this work, we consider directed acyclic networks of bistable units and we investigate the coupling effects on the Hopf bifurcations occurrence and on the number of equilibria of the entire network. (joint work with N. Corson and N. Verdiere)

  • 11:00 - Marc Barthelemy (Institut de Physique Theorique, CEA-IPhT, CNRS URA 2306, Gif-sur-Yvette, France)
    • Revisiting urban economics

      Always more data about cities are available which allows to build and to test theories and models. In particular, many urban economics models were developed to describe how cities are organized and I will discuss here their predictions about urban mobility. I will illustrate on various examples such as the total commuting length in cities, or the variation of the commuting length with income, how empirical data force us to reconsider these models in order to reach conclusions that are in agreement with empirical observations.

      Marc Barthelemy is a former student of the Ecole Normale Superieure of Paris and graduated in 1992 at the University of Paris VI with a thesis in theoretical physics titled "Random walks in random media". Since 1992, he has held a permanent position at the CEA (Paris) and since 2009 is a senior researcher at the Institute of Theoretical Physics (IPhT) in Saclay and a member of the Center of Social Analysis and Mathematics (CAMS) at the Ecole des Hautes Etudes en Sciences Sociales (EHESS). His interests moved towards applications of statistical physics to complex systems, and focusing on both data analysis and modeling, Marc Barthelemy is currently working on various aspects of the emerging science of cities.

  • 11:25 - Imene Khames (LMI, Normandie Univ, INSAROUEN, France)
    • Mode coupling in a nonlinear network

      We consider a graph wave equation with a cubic defocusing non-linearity on a general network. This well-posed model is close to the $\phi^4$ model in condensed matter physics. Using the normal modes of the graph Laplacian as a basis, we derive amplitude equations and define resonance conditions that relate the graph structure to the dynamics.

      Imene Khames is a doctoral student at the Laboratoire de Mathematiques de l'INSA de Rouen. She did her batchelor in Oran (Algeria) and her Master in Mathematics at the University of Nice.

  • 11:50 - M.A. Aziz-Alaoui, C. Bertelle & J. Zhao (LMAH, LITIS, Normandie Univ, UNIHAVRE, France & Hunan University of Commerce, China )
    • Cluster Synchronization of Complex Networks

      Cluster synchronization is an interesting issue in complex dynamical networks with community structure. We study this phenomenon, in which individuals in the same cluster are identical, while those in different clusters are not. Some sufficient conditions that ensure cluster synchronization of complex networks are provided. The increase of coupling strength inside clusters is very useful to achieve cluster synchronization, however, the coupling among different clusters is an obstacle.

  • 12:15 - Discussion and Conclusion