Réseaux sociaux :

derniers depôts

Ajouté le 20/07/2019

[hal-01672898] Strain gradient and generalized continua obtained by homogenizing frame lattices

We determine the effective behavior of periodic structures made of welded elastic bars. Taking into account the fact that flexural and torsional stiffnesses are much smaller than the extensional one we overpass classical homogenization formula and obtain totally different types of effective energies. We work in the framework of linear elasticity.

Ajouté le 20/07/2019

[hal-02188761] External sound field simulations and measurements of woodwind resonators

The input impedance is a useful quantity to characterize the acoustic response of woodwind instruments and is efficiently simulated using the Transfer Matrix Method (TMM). However, the TMM does not calculate intermediate variables that are convenient for simulating the external sound field.

Ajouté le 20/07/2019

[hal-02189163] Manipulation expérimentale de la cohérence temporelle d'ondes partiellement cohérentes

Nous décrivons deux expériences nous permettant de manipuler les propriétés de cohérence d'ondes partiellement cohérentes. Les montages expérimentaux développés reposent sur la manipulation de la phase spectrale du champ initial, assistée éventuellement d'une modulation sinusoïdale préalable de sa phase temporelle. Les signaux d'autocorrélation en intensité mesurés soulignent le changement significatif des caractéristiques temporelles des signaux incohérents obtenus.

Ajouté le 20/07/2019

[hal-02189191] Partial sums of the cotangent function

We prove the existence of reciprocity formulae for sums of the form $\sum_{m=1}^{k-1}f\pr{\frac{m}{k}}\cot\pr{\pi \frac{m h}k}$ where $f$ is a piecewise~$C^1$ function, featuring an alternating phenomenon not visible in the classical case where~$f(x)=x$. We deduce bounds for these sums in terms of the continued fraction expansion of~$h/k$.

Ajouté le 21/07/2019

[hal-02188478] Lytic xylan oxidases from wood-decay fungi unlock biomass degradation

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Ajouté le 19/07/2019

[hal-02186692] Analysis of a Sugimoto's model of nonlinear acoustics in an array of Helmholtz resonators

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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

[tel-02187453] Three dimensional X-ray Bragg ptychography of an extended semiconductor heterostructure

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 20/07/2019

[hal-02187791] The ectomycorrhizal basidiomycete Laccaria bicolor releases a secreted endocellulase that plays a key role in symbiosis development

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Ajouté le 19/07/2019

[hal-02174477] A scalable estimator of sets of integral operators

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.