October 22, 2014, ESB 2001

We study a new model of opinion dynamics in social networks which has two main features. First, agents asynchronously interact in pairs, and these pairs are chosen according to a random process. Following recent literature, we refer to this communication model as "gossiping''. Second, agents are not completely open-minded, but instead they take into account their initial opinions, which may be thought of as their "prejudices''. In the literature, such agents are often called "stubborn". We show that the opinions of the agents fail to converge, but persistently undergo ergodic oscillations, which asymptotically concentrate around a mean distribution of opinions. This mean value is exactly the limit of the synchronous dynamics of the expected opinions. In the second part of the talk, we demonstrate how a modified version of this approach is useful in sensor networks. In particular, we consider clock synchronization and show that the solution is obtained by means of a distributed least-squares randomized algorithm, provided that a suitable time-averaging operation is performed.

Roberto Tempo is currently a Director of Research of Systems and Computer Engineering at CNR-IEIIT, Politecnico di Torino, Italy. He has held visiting and research positions at Chinese Academy of Sciences in Beijing, Kyoto University, The University of Tokyo, University of Illinois at Urbana-Champaign, German Aerospace Research Organization in Oberpfaffenhofen and Columbia University in New York. His research activities are focused on the analysis and design of complex systems with uncertainty and various applications within information technology. On these topics, he has published more than 180 research papers in international journals, books and conferences. He is also a co-author of the book "Randomized Algorithms for Analysis and Control of Uncertain Systems," Springer-Verlag, London, published in two editions in 2005 and 2013.

He is a Fellow of the IEEE for "Contributions to Robust Identification and Control of Uncertain Systems" and a Fellow of the International Federation of Automatic Control (IFAC) for "Contributions to the Analysis and Control of Uncertain Systems, for Pioneering the Probabilistic Approach to Robustness." He is a recipient of the IFAC Outstanding Paper Prize Award for a paper published in Automatica and of the Distinguished Member Award from the IEEE Control Systems Society. He is a Corresponding Member of the Academy of Sciences, Institute of Bologna, Italy, Class Physical Sciences, Section Technical Sciences.

In 2010 Dr. Tempo has served the IEEE Control Systems Society as President. He was General Co-Chair for the IEEE Conference on Decision and Control, which was held in Florence, Italy, in 2013 and Program Chair of the first joint IEEE Conference on Decision and Control and European Control Conference, Seville, Spain, 2005. He is currently an Editor and Deputy Editor-in-Chief of Automatica, a Senior Editor of the IEEE Transactions on Automatic Control, a member of the Advisory Committee of the IEEE Transactions on Control of Network Systems, and an Editor at Large of the Asian Journal of Control. He has been Editor for Technical Notes and Correspondence of the IEEE Transactions on Automatic Control in 2005-2009.