Rate of convergence of the Swendsen-Wang dynamics in image segmentation problems : a theoretical and experimental study
We study in this paper the convergence rate of the Swendsen-Wang dynamics towards its equilibrium law, when the energy belongs to a large family of energies used in image segmentation problems. We compute the exponential equivalents of the transitions which control the process at low temperature, as well as the critical constant which gives its convergence rate. We give some theoretical tools to compare this dynamics with Metropolis, and develop an experimental study in order to calibrate...
Des semi-groupes de Feller locaux, deux à deux compatibles et définis sur des ouverts recouvrant un espace compact , se recollent en un semi-groupe de Feller local unique défini sur . Le principe du maximum joue un rôle essentiel dans la démonstration de ce résultat. Un théorème de recollement des générateurs infinitésimaux s’en déduit.
The properties of a certain generalization of simple random walk to continuous time are analyzed in this paper. After the definition, its transition probabilities, and the differential equations satisfied by those, are obtained. Under some conditions, the convergence of this random walk to a Wiener process is then established. Finally, absorption probabilities and mean times until absorption are calculated, giving some insight into the behaviour of the process.