Algèbre et géométrie, 1956-1994

Algèbre OLAP et langage graphique

This article deals with OLAP systems based on multidimensional model. The conceptual model we provide, represents data through a constellation (multi-facts) composed of several multi-hierarchy dimensions. In this model, data are displayed through multidimensional tables. We define a query algebra handling these tables. This user oriented algebra is composed of a closure core of OLAP operators a...

Team alien ALgèbre pour Identification et Estimation

Observation et stabilisation d ’ ondes : géométrie et coût du contrôle

Mémoire présenté pour l'habilitationà diriger des recherches, spécialité mathématiques.

Géométrie Des Groupes Oscillateurs Et Variétés Lo- Calement Symétriques

The Oscillator Groups,Gλ, are the only solvable, non commutative, simply connected Lie groups to admit a Lorentzian bi-invariant metric. For these groups, we give sufficient conditions for a left-invariant pseudo-Riemannian metric to be complete, we determine the group of isometries, we exhibit a left-invariant affine structure and prove that it is not Lorentzian. As an application, we provide ...

Algorithmique pour l'analyse et la modélisation en géométrie discrète

HAL is a multi-disciplinary open access archive for the deposit and dissemination of scientific research documents, whether they are published or not. The documents may come from teaching and research institutions in France or abroad, or from public or private research centers. L’archive ouverte pluridisciplinaire HAL, est destinée au dépôt et à la diffusion de documents scientifiques de niveau...