We are interested by Lyapounov exponents in the almost periodic Hamiltonian case.

In this paper we present a meta-heuristic, known as a genetic algorithm, in order to solve the problems of (weigthed) independent set (IS), vertex covering (VC), set packing (SP) and maximum clique (MC).

Galois connections (or residuated mapping) are of growing interest in various domains related with or relevant from Classification. Among their many uses, we select some topics related with modelization and aggregation of dissimilarities and conceptual classification. We partially revist them in...

The purpose of this paper is to extend Himmelberg's fixed point theorem replacing the usual convexity in topological vector spaces by an abstract topological notion of convexity which generalizes classical convexity as well as several metric convexity structures found in the literature. We prove...

The purpose of this paper is to show that the lattice Sn of permutations on a n-element set is bounded. This result strengthens the semi-distributive nature of the lattice Sn. To prove this property, we use a characterization of the class of bounded lattices in terms of arrows relations defined...