derniers depôts

Ajouté le 19/07/2019

We determine in the framework of static linear elasticity the homogenized behavior of three-dimensional periodic structures made of welded elastic bars.

Ajouté le 19/07/2019

Ptychography is a coherent diffraction imaging technique which aims in retrieving the lost phase from intensity-only far-field measurements. The versatility of the approach has proved an important asset for 3D mapping of different physical quantities, like the electron density of micrometer-sized specimens with resolution in the 10 - 100nm range.

Ajouté le 19/07/2019

The main objective of this work is to estimate a low dimensional subspace of operators in order to improve the identifiability of blind inverse problems. We propose a scalable method to find a subspace $\widehat \H$ of low-rank tensors that simultaneously approximates a set of integral operators. The method can be seen as a generalization of tensor decomposition models, which was never used in this context.

Ajouté le 18/07/2019

In this paper we obtain rigidity results for a bounded non-constant entire solution u of the Allen-Cahn equation in R n , whose level set {u = 0} is contained in a half-space. If n ≤ 3 we prove that the solution must be one-dimensional. In dimension n ≥ 4, we prove that either the solution is one-dimensional or stays below a one-dimensional solution and converges to it after suitable translations. Some generalizations to one phase free boundary problems are also obtained.

Ajouté le 17/07/2019

We present a statistical analysis of solar coronal mass ejections (CMEs) based on 23 years of quasi-continuous observations with the LASCO coronagraph, thus covering two complete Solar Cycles (23 and 24).

Ajouté le 17/07/2019

Meta-interface models stem from the homogenization, in a low-frequency dynamic regime, of thin heterogeneous layers that are structured to achieve uncommon properties at the macro-scopic level. When the layer is composed of a thin periodic array of highly-contrasted inclusions embedded within a homogeneous background medium then the corresponding effective interface model is characterized by jump conditions that, in the harmonic regime, involve some singular frequency-dependent terms.

Ajouté le 16/07/2019

L’optique ondulatoire est souvent enseignée à travers ses manifestations dans le domaine spatial : motifs d’interférence, figures de diffraction, propagation en espace libre... En exploitant le domaine de Fourier, il est possible de dresser une analogie formelle entre la diffraction 1D de la lumière et la dispersion subie par impulsion ultrabrève. Cela a permis la transposition de solutions connues de l’optique spatiale à l’optique temporelle.

Ajouté le 16/07/2019

The energy and momentum transfer between the atmosphere and the ocean has typically been studied for conditions where the waves have almost or already reached a local equilibrium with a uniform wind. The purpose of this work is to investigate the early stages of the generation of waves under non-stationary wind conditions and to describe the momentum and energy exchange at the air-water interface for non-equilibrium wind conditions.

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