Université Paris-Est Université Paris-Est - Marne-la-Vallée Université Paris-Est - Créteil Val-de-Marne Centre National de la Recherche Scientifique

Séminaire

Régression multivariée de faible rang

Site: 
Date: 
05/04/2011 - 10:30 - 11:30
Salle: 
2B 107
Orateur: 
GIRAUD Christophe
Localisation: 
École polytechnique
Localisation: 
France

Grandes matrices aléatoires de type Information - bruit et consistance d'estimateurs de direction d'arrivées dans le cas de réseaux d'antennes de grandes tailles

Site: 
Date: 
29/03/2011 - 10:30 - 11:30
Salle: 
2B 107
Orateur: 
LOUBATON Philippe
Localisation: 
Université de Marne-la-vallée
Localisation: 
France

Dominance stochastique par rapport à une capacité et une application financière

Site: 
Date: 
25/03/2011 - 15:00
Salle: 
3B 075
Orateur: 
GRIGOROVA Miryana
Localisation: 
Université Paris 7
Localisation: 
France

Déformation des triangles minimaux

Site: 
Date: 
28/03/2011 - 10:30
Salle: 
4B 05R
Orateur: 
COUTANT Antoine
Document(s): 

Étude probabiliste des résolutions de l'équation de coagulation

Site: 
Date: 
17/01/2011 - 10:30
Salle: 
4B 05R
Orateur: 
CEPEDA Eduardo
Document(s): 
Document(s): 
Résumé: 

Résumé des résultats de ma première année de thèse qui se trouvent dans l'article joint.
Plus une petite explication sur la fragmentation (extension) qui est le sujet de ma deuxième année.

Robust statistical inference and sparse transforms: results, links and perspectives

Site: 
Date: 
07/04/2011 - 15:00
Salle: 
I1 222
Orateur: 
PASTOR Dominique
Localisation: 
Télécom Bretagne
Localisation: 
France
Résumé: 

One of our research goal is the design of algorithms capable of detecting, with some robustness guaranteed by a suitable performance criterion, random signals with unknown distributions and occurrences in additive and stationary noise. This research is motivated by numerous practical applications where the lack of prior information about the signals or most of their describing parameters is an obstacle to the use of standard likelihood ratio theory. Several results established and assessed in various signal processing applications suggest that our goal could actually be attainable in a nearby future. Part of these results concern robust and non-parametric statistical inference based on assumptions of weak sparseness for the signal. The notion of weak sparseness slightly differs from that introduced by Donoho and Johnstone. Another set of results address statistical properties of the wavelet transform of wide-sense stationary random processes and fractional brownian motions. Some of the aforementioned results have been published separately, whereas others have been submitted only recently. Our purpose is then to present these results altogether so as to examine the links between them and pinpoint possible extensions. In particular, a perspective is the design of algorithms that perform more than the detection of random sigals with unknown distributions, but actually acquire statistical knowledge about these signals to optimize their detection. Beyond the description of standard possible applications in image processing and non-parametric statistics, the presentation will also give the opportunity to initiate a discussion on the application of these results to the design of new types of cell automata.

Typical points for one-parameter families of piecewise expanding unimodal maps

Type: 
Type: 
Site: 
Date: 
11/03/2011 - 10:30
Salle: 
204
Orateur: 
SCHNELLMANN Daniel
Localisation: 
ENS Paris
Localisation: 
France
Résumé: 

A piecewise expanding unimodal map on the unit interval admits a unique absolutely continuous invariant measure. By Birkhoff's Ergodic Theorem Lebesgue almost every point in the unit interval is typical for this measure, i.e., for each continuous function its time average along the forward orbit of a typical point is equal to its space average over the absolutely continuous invariant measure. In this talk we look at one-parameter families of piecewise expanding unimodal maps and we show that in the generic case there exists a set of full Lebesgue measure in the parameter space such that for each map corresponding to a parameter in this set the turning point is typical for the absolutely continuous invariant measure. This almost sure typicality result in the parameter space also applies to points different from the turning point.

Construction of complete hyperbolic minimal surfaces

Site: 
Date: 
28/03/2011 - 14:00
Salle: 
0D 01
Orateur: 
ALARCON Antonio
Localisation: 
Université de Grenade
Localisation: 
Espagne
Résumé: 

Until the eighties, it was a general though that hyperbolic surfacesplayed a marginal role in the theory of minimal surfaces in Euclidean $3$-space. However the constructions of Jorge-Meeks in 1980 and Nadirashvili in 1996 have inspired the proof of general existence theorems for complete hyperbolic minimal surfaces. In this talk, we will discuss some techniques of construction of such surfaces and show several applications.

Asymptotic Dirichlet problems for Laplace's and minimal equations on Hadamard manifolds

Site: 
Date: 
21/03/2011 - 14:00
Salle: 
0D 01
Orateur: 
RIPOLL Jaime
Localisation: 
Université fédérale du Rio Grande do Sul
Localisation: 
Brésil
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