Due to an unforseen circumstance, this seminar has been cancelled.
Professor Ramavarapu "RS" Sreenivas,
Industrial and Enterprise Systems Engineering,
University of Illinois at Urbana-Champaign,
On Supervisory Policies for Livelock Avoidance in Petri Net Models of Discrete State Systems
A Discrete-Event/Discrete-State (DEDS) system is in a livelocked-state, if some process has entered into a state of suspended-animation for perpetuity. If every process of the DEDS system is in a state of suspended animation, the DEDS system is deadlocked. A livelock-free DEDS system does not have deadlocked-states, but a deadlock-free DEDS system can still experience livelocks. A livelock-prone DEDS system can be regulated by a liveness enforcing supervisory policy (LESP) to ensure the supervised-system is livelock-free. A LESP is said to be maximally permissive, if the fact that it prevents the occurrence of an event a state leads us to infer that every LESP, irrespective of the implementation-paradigm that is chosen, will do the same.
We concern ourselves with DEDS systems that are modeled using general Petri nets (PNs), and we review key results on the synthesis of the maximally permissive LESP for DEDS systems modeled by PNs using a series of illustrative examples and a software package designed explicitly for this purpose.
R.S. Sreenivas received a B.Tech. in Electrical Engineering from the Indian Institute of Technology, (IIT) Madras, India in 1985 and an M.S. and, in 1990, a Ph.D. in Electrical and Computer Engineering from Carnegie Mellon University in Pittsburgh, PA. He then moved to Harvard University as a Post-Doctoral Fellow in Decision and Control at what was then the Division of Applied Sciences. After a two-year stint at Harvard, he moved to the University of Illinois at Urbana-Champaign, where he is an Associate Professor and Associate Head for Graduate Studies with the Industrial and Enterprise Systems Engineering Department. He holds research appointments at the Coordinated Science Laboratory (CSL) and the Information Trust Institute (ITI), and is also an affiliate of the Electrical and Computer Engineering Department.
Invited by Professor John Thistle
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