Dr. Francesco Bullo
Department of Mechanical Engineering
Center for Control, Dynamical Systems, and Computation
College of Engineering
University of California at Santa Barbara
bullo@engineering.ucsb.edu

Lecture Title: Opinion Dynamics and the Evolution of Social Influence Networks

Joint work with: Peng Jia, Anahita MirTabatabaei and Noah E. Friedkin.

This paper studies the evolution of self appraisal, social power and interpersonal influences for a group of individuals who discuss and form opinions about a sequence of issues. Our empirical model combines the averaging rule by DeGroot to describe opinion formation processes and the reflected appraisal mechanism by Friedkin to describe the dynamics of individuals’ self appraisal and social power. Given a set of relative interpersonal weights, the DeGroot-Friedkin model predicts the evolution of the influence network governing the opinion formation process. We provide a rigorous mathematical formulation of the influence network dynamics, characterize its equilibria and establish its convergence properties for all possible structures of the relative interpersonal weights and corresponding eigenvector centrality scores. The model predicts that the social power ranking among individuals is asymptotically equal to their centrality ranking, that social power tends to accumulate at the top of the hierarchy, and that an autocratic (resp. democratic) power structure arises when the centrality scores are maximally non-uniform (resp. uniform).

Speaker Bio:

Francesco Bullo is a Professor with the Mechanical Engineering Department at the University of California, Santa Barbara. He received the Laurea degree “summa cum laude” in Electrical Engineering from the University of Padova, Italy, in 1994, and the Ph.D. degree in Control and Dynamical Systems from the California Institute of Technology in 1999. From 1998 to 2004, he was an Assistant Professor with the Coordinated Science Laboratory at the University of Illinois at Urbana-Champaign.

His main research interest is multi-agent networks with application to robotic coordination, distributed computing and power networks. Other interests include vehicle routing, geometric control, and motion planning problems. He is the coauthor, with Andrew D. Lewis, of the book “Geometric Control of Mechanical Systems” (Springer, 2004, 0-387-22195-6) and, with Jorge Cortés and Sonia Martínez, of the book “Distributed Control of Robotic Networks” (Princeton, 2009, 978-0-691-14195-4). He is an IEEE Fellow. His students’ papers were finalists for the Best Student Paper Award at the IEEE Conference on Decision and Control (2002, 2005, 2007), and the American Control Conference (2005, 2006, 2010). He is a recipient of the 2003 ONR Young Investigator Award, the 2008 IEEE CSM Outstanding Paper Award and the 2010 Hugo Schuck Best Paper Award. He has published more than 200 papers in international journals, books, and refereed conferences. He has served or is serving on the Editorial Boards of “IEEE Transactions on Automatic Control,” “ESAIM: Control, Optimization, and the Calculus of Variations,” “SIAM Journal of Control and Optimization,” and “Mathematics of Control, Signals, and Systems”.