Arturo Buscarino, Dipartimento di Ingegneria Elettrica Elettronica e dei Sistemi, Universita degli Studi di Catania, Italy The synchronization of chaotic system and the analysis of agent-based models Abstract: In this talk two aspects related to the study of complex systems will be discussed: the synchronization of chaotic systems and the analysis of agent- based models. In particular, the problem of separation and synchronization of chaotic systems (i.e. the synchronization of different chaotic dynamics through a unique scalar signal) will be examined. Two strategies to obtain synchronization of multiplexed systems will be described: the first, based on Linear Matrix Inequalities, deals to the design of an observer for piece-wise linear chaotic systems; the second strategy, based on the evaluation of the Master Stability Function of multiplexed systems, permits the extension of the separation and synchronization problem to chaotic system with smooth nonlinearities. Numerical and experimental results will be also shown. The second part of the talk will focus on the possible link between agent- based modeling and network theory. A distributed control scheme of roving robots based on Vicsek's model will be introduced. A Mobile agents model able to simulate the spreading of a virus in a population of interacting particles will be also described focusing on how such kind of models can be studied as dynamical networks.