Mercredi 16 décembre 2020, 11h - 12h, {\small}

Diagnosis and Opacity in Partially Observable Systems

Stefan Schwoon, ENS Paris-Saclay

In a partially observable system, diagnosis is the task of detecting certain events, for instance fault occurrences. In the presence of hostile observers, on the other hand, one is interested in rendering a system opaque, i.e. making it impossible to detect certain "secret" events. The talk will present some decidability and complexity results for these two problems when the system is represented as a finite automaton or a Petri net. We then also consider the problem of active diagnosis, where the observer has some control over the system. In this context, we study problems such as the computational complexity of the synthesis problem, the memory required for the controller, and the delay between a fault occurrence and its detection by the diagnoser. The talk is based on joint work with B. Bérard, S. Haar, S. Haddad, T. Melliti, and S. Schmitz.

Stefan Schwoon studied Computer Science at the University of Hildesheim and received a PhD from the Technical University of Munich in 2002. He held the position of Scientific Assistent at the University of Stuttgart from 2002 to 2007, and at the Technical University in Munich from 2007 to 2009. He is currently Associate Professor (Maître de conférences) at Laboratoire Spécification et Vérification (LSV), ENS Paris-Saclay, and a member of the INRIA team Mexico. His research interests include model checking and diagnosis on concurrent and partially-observable systems.