La prochaine séance du séminaire Combi du Plateau de Saclay aura lieu ce mercredi à 11h dans la salle Henri Poincaré du LIX (au rez-de-chaussée, aux 3/4 du corridor, sur la gauche). Il s’agit d’un séminaire joint avec l’équipe AlCo. Nous aurons le plaisir d’écouter Anaël Grandjean (Université de Créteil) nous donner un exposé sur «L-Convex Polyominoes are Recognizable in Real Time by 2D Cellular Automata». Le résumé est disponible ci-dessous.

Le programme du séminaire est disponible ici : https://galac.lri.fr/pages/combi-seminar.html

Résumé: This is a joint work with Victor Poupet where we investigate the recognition power of cellular automata in real time. A polyomino is said to be L-convex if any two of its cells are connected by a 4-connected inner path that changes direction at most once. The 2-dimensional language representing such polyominoes has been recently proved to be recognizable by tiling systems by S. Brocchi, A. Frosini, R. Pinzani and S. Rinaldi. In an attempt to compare recognition power of tiling systems and cellular automata, we have proved that this language can be recognized by 2-dimensional cellular automata working on the von Neumann neighborhood in real time. Although the construction uses a characterization of L-convex polyominoes that is similar to the one used for tiling systems, the real time constraint which has no equivalent in terms of tilings requires the use of techniques that are specific to cellular automata.