Hyperbolicity of singular spaces

We study the hyperbolicity of singular quotients of bounded symmetric domains. We give effective criteria for such quotients to satisfy Green-Griffiths-Lang's conjectures in both analytic and algebraic settings. As an application, we show that Hilbert modular varieties, except for a few possible exceptions, satisfy all expected conjectures.Comment: Main results extended to arbitrary quotient singularities and all bounded symmetric domain

Radiative Thermal Rectification between SiC and SiO2

By means of fluctuationnal electrodynamics, we calculate radiative heat flux between two pla-nar materials respectively made of SiC and SiO2. More specifically, we focus on a first (direct) situation where one of the two materials (for example SiC) is at ambient temperature whereas the second material is at a higher one, then we study a second (reverse) situation where the material temperatures are inverted. When the two fluxes corresponding to the two situations are different, the materials are said to exhibit a thermal rectification, a property with potential applications in thermal regulation. Rectification variations with temperature and separation distance are here reported. Calculations are performed using material optical data experimentally determined by Fourier transform emission spectrometry of heated materials between ambient temperature (around 300 K) and 1480 K. It is shown that rectification is much more important in the near-field domain, i.e. at separation distances smaller than the thermal wavelength. In addition, we see that the larger is the temperature difference, the larger is rectification. Large rectification is finally interpreted due to a weakening of the SiC surface polariton when temperature increases, a weakening which affects much less SiO2 resonances

Relations parents immigrants-écoles dans l’espace montréalais : au-delà des tensions, la rencontre des rêves

La récente controverse autour des accommodements raisonnables met en relief les enjeux identitaires, dans les écoles qui desservent une clientèle de plus en plus pluriethnique. La création des liens parents immigrants-écoles, essentielle et souhaitée, est modulée par des tensions sociales et politiques et représente un défi parfois difficile à relever. Cet article rapporte les résultats de groupes de discussion avec des parents et des enseignants dans deux écoles montréalaises, dans le but de documenter la relation parents immigrants-écoles. S’inspirant des recommandations formulées par les participants, la discussion offre des pistes pour repenser les échanges entre les parents et la communauté afin de générer des domaines de compréhension partagée.The recent controversy over reasonable accommodation has underscored identity issues in the increasingly multiethnic student population of Montreal schools. While the establishment of good relations between immigrant parents and schools is essential and to be encouraged, it is subject to sociopolitical tensions and represents a sometimes daunting challenge. In this article, the results of parent-teacher focus groups that were organized in two Montreal schools to collect data on these relations are presented. Building on recommendations made by parents and teachers, the article suggests avenues for rethinking interaction between parents and the community as a way of laying the groundwork for mutual understanding.La reciente controversia alrededor de los acomodamientos razonables hace resaltar los retos identitarios en las escuelas que atienden a una clientela cada vez más multiétnica. La creación de los vínculos padres inmigrantes - escuelas, esencial y deseada, está modulada por tensiones sociales y políticas y representa un desafío a veces difícil de enfrentar. Este artículo presenta los resultados de unos grupos de discusión con padres y maestros en dos escuelas de Montreal, con el propósito de documentar la relación padres inmigrantes - escuelas. Inspirándose de las recomendaciones formuladas por los participantes, la discusión ofrece pistas para repensar los intercambios entre los padres y la comunicad, con la finalidad de generar dominios de comprensión compartida

Skew products, quantitative recurrence, shrinking targets and decay of correlations

We consider toral extensions of hyperbolic dynamical systems. We prove that its quantitative recurrence (also with respect to given observables) and hitting time scale behavior depend on the arithmetical properties of the extension. By this we show that those systems have a polynomial decay of correlations with respect to $C^{r}$ observables, and give estimations for its exponent, which depend on $r$ and on the arithmetical properties of the system. We also show examples of systems of this kind having not the shrinking target property, and having a trivial limit distribution of return time statistics

Lecture automatique d'un ticket de caisse par vision embarquée sur un téléphone mobile

Travaux réalisés dans le cadre d'une thèse CIFRENational audienceThis work addresses the automatic reading of sale receipts acquired with a smartphone's camera and the extraction of essential informations like the store brands, all the purchased products , their price etc. It is divided into two major tasks : the optical character recognition that is made complex due to the nature of the document often damaged, crumpled or torned and the semantic data analysis to identify purchased product without ambiguity. In this paper, we introduce a solution that enables a "guided" capture on smartphone and a receipt decoding on remote server.L'objectif de ces travaux est de créer un système capable, à partir d'une simple vue prise par un smartphone, d'exploiter le contenu d'un ticket de caisse, et d'en extraire des informations telles que le point de vente, les produits ache-tés, leurs prix etc. On distingue deux étapes majeures : la reconnaissance optique de caractères sur des tickets qui peuvent être froissés, déchirés... et l'analyse sémantique afin d'identifier les produits achetés sans ambiguïté. Dans ce papier, nous présentons une solution qui effectue une acquisition "guidée" d'une image sur smartphone et une lecture du contenu sur un serveur distant

Prediction of thermal radiative properties (300–1000 K) of La2NiO4+δ ceramics.

A multiscale numerical model is developed to predict the thermal radiative properties (TRP) of rough La2NiO4+δ coatings. The model integrates intrinsic and extrinsic contributions related to the chemical composition and the texture, respectively. High-temperature infrared reflectivity and thermogravimetric measurements on a La2NiO4+δ single crystal make it possible to understand the role of the excess oxygen in the intrinsic TRP. We show that dense ceramics with thicknesses higher than 4 μm are optically thick, and that one can adjust the surface roughness parameters to predict their TRP

Modelling of the radiative properties of an opaque porous ceramic layer

Solid Oxide Fuel Cells (SOFCs) operate at temperatures above 1,100 K where radiation effects can be significant. Therefore, an accurate thermal model of an SOFC requires the inclusion of the contribution of thermal radiation. This implies that the thermal radiative properties of the oxide ceramics used in the design of SOFCs must be known. However, little information can be found in the literature concerning their operating temperatures. On the other hand, several types of ceramics with different chemical compositions and microstructures for designing efficient cells are now being tested. This is a situation where the use of a numerical tool making possible the prediction of the thermal radiative properties of SOFC materials, whatever their chemical composition and microstructure are, may be a decisive help. Using this method, first attempts to predict the radiative properties of a lanthanum nickelate porous layer deposited onto an yttria stabilized zirconium substrate can be reported

Nutritional approach for inhibiting bone resorption in institutionalized elderly women with vitamin D insufficiency and high prevalence of fracture

Background: Nutritional approach to the deterioration of bone integrity and increased fracture risk appears to be particularly appropriate in elderly women living in nursing homes. Objective: To investigate the beneficial effect of the consumption of soft plain cheese on bone resorption markers in institutionalized elderly women. Design: Prospective, randomized crossover controlled study. Setting: Six French nursing homes or other institutions for elderly. Participants: Institutionalized women ≥ 65 years old with low vitamin D status and calcium intake below 700 mg/day. Intervention: Consumption of soft plain cheese made of semi-skimmed milk which was fortified by both vitamin D3 (+ 1.25µg/100g) and milk extracted Ca, thus achieving a total Ca content of 151 mg/100g as compared to about 118 mg/100g for standard fresh cheese. Two servings were taken every day during the 6 weeks that preceded or followed a period of 6 weeks without soft plain cheese consumption. Measurements: The primary end point was the change in serum carboxy terminal cross-linked telopeptide of type I collagen (CTX) selected as a marker of bone resorption. Results: 29 women aged 73-94 yr were selected, 21 of them with mean age 87.2±6.1 years remained compliant The intervention increased calcium and protein intakes by 51% (904±228 vs. 599±122 mg/d) and 33 % (74.2±17.1 vs. 55.6±12.7 g/d, mean±SD), respectively. The dietary intervention was associated with a statistically significant increase in serum levels of both 25OHD and IGF-I, while those of PTH, CTX and TRAP5b were significantly reduced. Compliance was 93,4 %. The daily consumption of two servings of soft plain cheese was well accepted in terms of tastiness and appetite suited portion size. Conclusion: This randomized crossover controlled trial demonstrates that in elderly women living in nursing homes, the consumption of soft plain cheese increasing the supply of vitamin D, calcium and proteins, could reduce bone resorption and thereby reduce the risk of incidental fragility fractures in the long ter