活动/讲座时间：2015-03-26 下午16:00-17:00
活动/讲座地点：西南交大（九里校区）工程中心4楼403（牵引动力国家重点实验室院内）
活动/讲座嘉宾：Claudio Altafini，瑞典林雪平大学教授，IEEE自动控制会刊副主编
嘉宾介绍：

Claudio Altafini received the M.S. degree (“Laurea”) in electrical engineering from the University of Padova, Padova, Italy, in 1996 and the PhD degree in optimization and systems theory from the

Royal Institute of Technology, Stockholm, Sweden, in 2001. From 2001 to 2013, he was with the International School for Advanced Studies (SISSA), Trieste, Italy. Since 2014 he has been a Professor in the Division of Automatic Control, Department of Electrical Engineering, Link?ping University, Sweden. His research interests are in the areas of nonlinear systems analysis and control, with applications to quantum mechanics, systems biology, and complex networks. Dr. Altafini is an Associate Editor for the IEEE TRANSACTIONS ON AUTOMATIC CONTROL.

主要内容：

Being able to predict the outcome of an opinion forming process is an important problem in social network theory. For communities of agents which are not necessarily cooperating, distributed processes of opinion forming are naturally represented by signed graphs, with positive edges representing friendly and cooperative interactions among the agents and negative edges the corresponding antagonistic counterpart. Unlike for networks of cooperating agents, the outcome of a dynamical system evolving on such signed graphs is not obvious and it is in general difficult to characterize, even when the dynamics are linear. In this talk I will discuss cases in which predicting the dynamics from the signature of the graph is however possible. These include: (i) structurally balanced graphs, which induce monotone dynamics; (ii) cases in which the Perron-Frobenius theorem can be applied. The latter correspond to linear systems admitting an invariant cone properly contained in one of the orthants of R^n. When the cone is contained in the first orthant, then the social network achieves an unanimous opinion in spite of the presence of antagonism.