Publications

2000

• Images du Virtuel
  
  • Colonna Jean-François
  , 2000. Images calculees lors d'experiences virtuelles a partir de modeles mathematiques de systemes physiques.
• Images du Virtuel
  
  • Colonna Jean-François
  , 2000. Images calculees lors d'experiences virtuelles a partir de modeles mathematiques de systemes physiques.
• Junior Automata
  
  • Boussinot Frédéric
  , 2000, pp.23. One describes the way to produce finite states machines from programs written in Junior, a formalism for reactive programming in Java. The paper proposes the notion of a partial automaton for dealing with large size numbers of states.
• Images du Virtuel
  
  • Colonna Jean-François
  , 2000. Images calculees lors d'experiences virtuelles a partir de modeles mathematiques de systemes physiques.
• Images du Virtuel
  
  • Colonna Jean-François
  , 2000. Images calculees lors d'experiences virtuelles a partir de modeles mathematiques de systemes physiques.
• Images du Virtuel
  
  • Colonna Jean-François
  , 2000. Images calculees lors d'experiences virtuelles a partir de modeles mathematiques de systemes physiques.
• Images du Virtuel
  
  • Colonna Jean-François
  , 2000. Images calculees lors d'experiences virtuelles a partir de modeles mathematiques de systemes physiques.
• Images du Virtuel
  
  • Colonna Jean-François
  , 2000. Images calculees lors d'experiences virtuelles a partir de modeles mathematiques de systemes physiques.
• A multivariate multifractal model for return fluctuations
  
  • Bacry Emmanuel
  • Delour J.
  • Muzy J. F.
  , 2000. In this paper we briefly review the recently inrtroduced Multifractal Random Walk (MRW) that is able to reproduce most of recent empirical findings concerning financial time-series : no correlation between price variations, long-range volatility correlations and multifractal statistics. We then focus on its extension to a multivariate context in order to model portfolio behavior. Empirical estimations on real data suggest that this approach can be pertinent to account for the nature of both linear and non-linear correlation between stock returns at all time scales.
• La programmation en Junior
  
  • Boussinot Frédéric
  • Hazard Laurent
  • Susini Jean-Ferdy
  , 2000, pp.31. {\Junior est un langage construit au dessus de Java pour programmer des comportements réactifs. Il autorise la concurrence, les événements diffusés et définit plusieurs primitives permettant d'obtenir un contrôle fin sur l'exécution des programmes réactifs. Il est utilisé au travers d'une API, nommée Jr, qui masque les implémentations existantes.
• Images du Virtuel
  
  • Colonna Jean-François
  , 2000. Images calculees lors d'experiences virtuelles a partir de modeles mathematiques de systemes physiques.
• Images du Virtuel
  
  • Colonna Jean-François
  , 2000. Images calculees lors d'experiences virtuelles a partir de modeles mathematiques de systemes physiques.
• Images du Virtuel
  
  • Colonna Jean-François
  , 2000. Images calculees lors d'experiences virtuelles a partir de modeles mathematiques de systemes physiques.
• Images du Virtuel
  
  • Colonna Jean-François
  , 2000. Images calculees lors d'experiences virtuelles a partir de modeles mathematiques de systemes physiques.
• More about vanishing cycles and mutation
  
  • Seidel Paul
  , 2000. The paper continues the discussion of symplectic aspects of Picard-Lefschetz theory begun in "Vanishing cycles and mutation" (this archive). There we explained how to associate to a suitable fibration over a two-dimensional disc a triangulated category, the "derived directed Fukaya category" which describes the structure of the vanishing cycles. The present second part serves two purposes. Firstly, it contains various kinds of algebro-geometric examples, including the "mirror manifold" of the projective plane. Secondly there is a (largely conjectural) discussion of more advanced topics, such as (i) Hochschild cohomology, (ii) relations between Picard-Lefschetz theory and Morse theory, (iii) a proposed "dimensional reduction" algorithm for doing certain Floer cohomology computations.
• Images du Virtuel
  
  • Colonna Jean-François
  , 2000. Images calculees lors d'experiences virtuelles a partir de modeles mathematiques de systemes physiques.
• Images du Virtuel
  
  • Colonna Jean-François
  , 2000. Images calculees lors d'experiences virtuelles a partir de modeles mathematiques de systemes physiques.
• Images du Virtuel
  
  • Colonna Jean-François
  , 2000. Images calculees lors d'experiences virtuelles a partir de modeles mathematiques de systemes physiques.
• Images du Virtuel
  
  • Colonna Jean-François
  , 2000. Images calculees lors d'experiences virtuelles a partir de modeles mathematiques de systemes physiques.
• Images du Virtuel
  
  • Colonna Jean-François
  , 2000. Images calculees lors d'experiences virtuelles a partir de modeles mathematiques de systemes physiques.
• Images du Virtuel
  
  • Colonna Jean-François
  , 2000. Images calculees lors d'experiences virtuelles a partir de modeles mathematiques de systemes physiques.
• Images du Virtuel
  
  • Colonna Jean-François
  , 2000. Images calculees lors d'experiences virtuelles a partir de modeles mathematiques de systemes physiques.
• Homogenization of a spectral problem in neutronic multigroup diffusion
  
  • Allaire Grégoire
  • Capdeboscq Yves
  Computer Methods in Applied Mechanics and Engineering, Elsevier, 2000, 187 (1-2), pp.91--117. This paper is concerned with the homogenization of an eigenvalue problem in a periodic heterogeneous domain for the multigroup neutron diffusion system. Such a model is used for studying the criticality of nuclear reactor cores. We prove that the first eigenvector of the multigroup system in the periodicity cell controls the oscillatory behaviour of the solutions, whereas the global trend is asymptotically given by a homogenized diffusion eigenvalue problem. The neutron flux, corresponding to the first eigenvector of the multigroup system, tends to the product of the first periodic and homogenized eigenvectors. This result justifies and improves the engineering procedure used in practice for nuclear reactor core computation. (10.1016/S0045-7825(99)00112-7)
  DOI : 10.1016/S0045-7825(99)00112-7
• Polar IFS + Parisian GP = Efficient IFS inverse problem solving
  
  • Collet Pierre
  • Lutton Evelyne
  • Raynal Frédéric
  • Schoenauer Marc
  Genetic Programming and Evolvable Machines, Springer Verlag, 2000, 1 (4), pp.339-361. The inverse problem for Iterated Functions Systems (finding an IFS whose attractor is a target 2D shape) with non-affine IFS is a very complex task. Successful approaches have been made using Genetic Programming, but there is still room for improvement in both the IFS and the GP parts. This paper introduces Polar IFS: a specific representation of IFS functions which shrinks the search space to mostly contractive functions and gives direct access to the fixed points of the functions. On the evolutionary side, the ``Parisian'' approach is presented. It is similar to the ``Michigan'' approach of Classifier Systems: each individual of the population only represents a part of the global solution. The solution to the inverse problem for IFS is then built from a set of individuals. Both improvements show a drastic cut-down on CPU-time: good results are obtained with small populations in few generations.
• Images du Virtuel
  
  • Colonna Jean-François
  , 2000. Images calculees lors d'experiences virtuelles a partir de modeles mathematiques de systemes physiques.