Understanding Sub-Second Instabilities in a Global Cyber-Physical System

Abstract: Future CPS will include large, decentralized systems of semi-autonomous sensor and actuator components, and will need to operate safely beyond human response times. One current data-rich example is the U.S. network of electronic exchange networks which is the largest and fastest network CPS in existence, but is already known to produce a wide variety of sub-second instabilities that are little understood and which impact safety, efficiency and accuracy. Urgent questions facing such CPS systems are therefore: When do extreme and hence potentially unsafe behaviors occur in CPS, in particular in the sub-second regime beyond human intervention times? Can they be predicted? How can they be managed or prevented? This project addresses these questions by developing a new scalable theory of CPS dynamical behavior, focused on this sub-second regime beyond human intervention times. The theory will be validated and verified using rigorous mathematical analysis and real-world data. The analysis considers CPS as decentralized networks of heterogeneous semi- autonomous machinery in which an ecology of algorithms, sensors and network links may be operating, adapting and even competing in response to external inputs. It will employ ideas and techniques developed in the fields of complex systems and many-body analysis. It represents new science, not just for applications of CPS but also for the core question of dynamical behavior of CPS complex systems. The project's deliverables will inform the extent to which instabilities can build up across timescales, potentially threatening CPS system stability on a global level. The theory will allow for networking at multiple scales, coupling across multiple temporal and spatial scales, imperfect network communications and sensors, as well as adaptive reorganization and reconfiguration of the system. Theoretical findings are cross-checked against available empirical data, e.g., from the decentralized network of autonomous market exchanges with its mandated sensor systems. The broader impacts include helping to improve safety and security for society's CPS systems, from financial networks, smart energy buildings and cities, to autonomous vehicle design, both at individual and swarm level. This project is already attracting interest from stakeholders at state, federal and international level.

Neil Johnson heads up a new inter-disciplinary research initiative in Complex Systems & Networks at the University of Miami, focusing on emergent dynamical phenomena across the physical and life sciences. Until 2007, Neil was Professor of Physics at Oxford University. He did his BA/MA at Cambridge University and his PhD at Harvard University as a Kennedy Scholar. He has published more than 250 research articles and two books: "Financial Market Complexity" (Oxford University Press, 2003) and "Simply Complexity: A Clear Guide to Complexity Theory" (Oneworld Publishing, 2009). He wrote and presented the Royal Institution Lectures in 1999 on BBC television. Publications at: http://www.physics.miami.edu/~njohnson/.