Computing and Mathematical Sciences Colloquium

The emergence of large networked systems has brought about new challenges to researchers and practitioners alike. While such systems perform well under normal operations, they can exhibit fragility in response to certain disruptions that may lead to catastrophic cascades of failures. This phenomenon, sometimes referred to as systemic risk, emphasizes the role of the system interconnection in causing such, possibly rare, events. The flash crash of 2010, the financial crisis of 2008, the New England power outage of 2003, or simply extensive delays in air travel, are just a few of many examples of fragility and systemic risk present in complex interconnected systems. In this talk I will discuss this emerging area for critical infrastructures. Such applications involve the interaction between physical systems and social networks. I will present simplified dynamic models from transportation systems and the power grid that highlight how such interactions impact fragility/resilience. I argue that co-design of both control strategies at the physical layer and incentive mechanism at the social layer is necessary to prevent fragility and systemic failures.