HUJSA Thomas

PhD graduated
Team : ALSOC
Departure date : 10/30/2014

Supervision : Alix MUNIER

Co-supervision : DELOSME Jean-Marc

Contribution to the study of weighted Petri nets

Many real systems and applications, including flexible manufacturing systems and embedded systems, are composed of communicating tasks and may be modeled by weighted Petri nets. The behavior of these systems can be checked on their model early on at the design phase, thus avoiding costly simulations on the designed systems.
Usually, the models should exhibit three basic properties: liveness, boundedness and reversibility. Liveness preserves the possibility of executing every task, while boundedness ensures that the operations can be performed with a bounded amount of resources. Reversibility avoids a costly initialization phase and allows resets of the system.
Most existing methods to analyse these properties have exponential time complexity. By focusing on several expressive subclasses of weighted Petri nets, namely Fork-Attribution, Choice-Free, Join-Free and Equal-Conflict nets, the first polynomial algorithms that ensure liveness, boundedness and reversibility for these classes have been developed in this thesis.
First, we provide several polynomial time transformations that preserve structural and behavioral properties of weighted Petri nets, while simplifying the study of their behavior. Second, we use these transformations to obtain several polynomial sufficient conditions of liveness for the subclasses considered. Finally, the transformations also prove useful for the study of the reversibility property under the liveness assumption. We provide several characterizations and polynomial sufficient conditions of reversibility for the same subclasses.
All our conditions are scalable and can be easily implemented in real systems.

Defence : 10/29/2014

Jury members :

M. Ahmed Bouajjani : Université Paris 7, LIAFA [Rapporteur]
M. José-Manuel Colom : Université de Saragosse, DIIS, GISED, Espagne [Rapporteur]
Mme. Feng Chu : Université d'Evry-Val d'Essonne, IBISC
Mme. Anne Bouillard : ENS Paris, DI
Mme. Béatrice Bérard : UPMC, LIP6
M. Serge Haddad : ENS Cachan, LSV
Mme. Alix Munier-Kordon : UPMC, LIP6
M. Jean-Marc Delosme : Université d'Evry-Val d'Essonne, IBISC

Departure date : 10/30/2014

2013-2016 Publications