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Bayesian Compressive Sensing Approaches for Direction of Arrival Estimation With Mutual Coupling Effects
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L’Espagne d’une politique au féminin à une politique féministe
No full textInternational audienceAprès la crise de 2008 qui a ébranlé l’Espagne et les mouvements sociaux qui en ont résulté, le féminisme et les questions de genre qui avaient déjà été au cœur de la politique de Zapatero ont gagné une nouvelle forme de visibilité. Désormais les deux capitales Madrid et Barcelone sont gouvernées par deux figures de femmes « puissantes », Manuela Carmena et Ada Colau. Mais ces deux femmes défendent deux postures différentes par rapport au féminisme. Alors que la première, qui appartient à la génération qui a connu le franquisme, met en avant la notion de la culture féminine, la seconde, née en 1974, défend ouvertement une politique féministe qui imprègne de manière transversale toute sa politique municipale
Fast and Differentially Private Algorithms for Decentralized Collaborative Machine Learning
No full textConsider a set of agents in a peer-to-peer communication network, where each agent has a personal dataset and a personal learning objective. The main question addressed in this paper is: how can agents collaborate to improve upon their locally learned model without leaking sensitive information about their data? Our first contribution is to reformulate this problem so that it can be solved by a block coordinate descent algorithm. We obtain an efficient and fully decentralized protocol working in an asynchronous fashion. Our second contribution is to make our algorithm differentially private to protect against the disclosure of any information about personal datasets. We prove convergence rates and exhibit the trade-off between utility and privacy. Our experiments show that our approach dramatically outperforms previous work in the non-private case, and that under privacy constraints we significantly improve over purely local models
Global scale variability of the mineral dust long-wave refractive index: a new dataset of in situ measurements for climate modeling and remote sensing
No full textInternational audienceModeling the interaction of dust with long-wave (LW) radiation is still a challenge because of the scarcity of information on the complex refractive index of dust from different source regions. In particular, little is known about the variability of the refractive index as a function of the dust mineralogical composition, which depends on the specific emission source, and its size distribution, which is modified during transport. As a consequence, to date, climate models and remote sensing retrievals generally use a spatially invariant and time-constant value for the dust LW refractive index.In this paper, the variability of the mineral dust LW refractive index as a function of its mineralogical composition and size distribution is explored by in situ measurements in a large smog chamber. Mineral dust aerosols were generated from 19 natural soils from 8 regions: northern Africa, the Sahel, eastern Africa and the Middle East, eastern Asia, North and South America, southern Africa, and Australia. Soil samples were selected from a total of 137 available samples in order to represent the diversity of sources from arid and semi-arid areas worldwide and to account for the heterogeneity of the soil composition at the global scale. Aerosol samples generated from soils were re-suspended in the chamber, where their LW extinction spectra (3–15 µm), size distribution, and mineralogical composition were measured. The generated aerosol exhibits a realistic size distribution and mineralogy, including both the sub- and super-micron fractions, and represents in typical atmospheric proportions the main LW-active minerals, such as clays, quartz, and calcite. The complex refractive index of the aerosol is obtained by an optical inversion based upon the measured extinction spectrum and size distribution.Results from the present study show that the imaginary LW refractive index (k) of dust varies greatly both in magnitude and spectral shape from sample to sample, reflecting the differences in particle composition. In the 3–15 µm spectral range, k is between ∼ 0.001 and 0.92. The strength of the dust absorption at ∼ 7 and 11.4 µm depends on the amount of calcite within the samples, while the absorption between 8 and 14 µm is determined by the relative abundance of quartz and clays. The imaginary part (k) is observed to vary both from region to region and for varying sources within the same region. Conversely, for the real part (n), which is in the range 0.84–1.94, values are observed to agree for all dust samples across most of the spectrum within the error bars. This implies that while a constant n can be probably assumed for dust from different sources, a varying k should be used both at the global and the regional scale. A linear relationship between the magnitude of the imaginary refractive index at 7.0, 9.2, and 11.4 µm and the mass concentration of calcite and quartz absorbing at these wavelengths was found. We suggest that this may lead to predictive rules to estimate the LW refractive index of dust in specific bands based on an assumed or predicted mineralogical composition, or conversely, to estimate the dust composition from measurements of the LW extinction at specific wavebands.Based on the results of the present study, we recommend that climate models and remote sensing instruments operating at infrared wavelengths, such as IASI (infrared atmospheric sounder interferometer), use regionally dependent refractive indices rather than generic values. Our observations also suggest that the refractive index of dust in the LW does not change as a result of the loss of coarse particles by gravitational settling, so that constant values of n and k could be assumed close to sources and following transport.The whole dataset of the dust complex refractive indices presented in this paper is made available to the scientific community in the Supplement
Correcting agglomeration economies: How air pollution matters
No full textThis paper aims to correct standard measures of agglomeration economies to account for air pollution. This paper examines the impact of nitrogen oxide (NOX) a pollutant mainly released by transportation on worker productivity. Literature on agglomeration economies highlights the positive role of employment density on productivity, without accounting for the negative impacts of local pollutants. First, standard estimates of agglomeration economies for the 304 French employment areas are in line with the literature. Then, we introduce the variable(NOX) emissions and, once pollution is accounted for, the estimated direct impact of agglomeration externalities on productivity are lower by more than 13 per cent
Supporting the sexual life of persons in situations of disability: a social history: Sociology of Sexuality section
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Newly discovered deep-branching marine plastid lineages are numerically rare but globally distributed
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Albert-Marie Schmidt, esquisse d'une figure littéraire
No full textInternational audienceBiographie d'Albert-Marie Schmidt (1901-1966). Professeur de littérature à la Faculté des lettres de Lille, A.-M. Schmidt est spécialiste de littérature du XVIe siècle mais s'intéresse également à la littérature moderne et contemporaine (en particulier éditeur de Maupassant). Figure du monde littéraire comme critique, il a participé à de très nombreuses revues. Il fut également lecteur dans des maisons d'édition, membres de jurys littéraires (en particulier le prix du Meilleur livre étranger), et l'un des fondateurs de l'Oulipo, dont il crée l'acronyme.C'est aussi une figure d''intellectuel protestant
Semantic correspondence across 3D models for example-based modeling
No full textInternational audienceModeling 3D shapes is a specialized skill not affordable to most novice artists due to its complexity and tediousness. At the same time, databases of complex models ready for use are becoming widespread, and can help the modeling task in a process called example-based modeling. We introduce such an example-based mesh modeling approach which, contrary to prior work, allows for the replacement of any localized region of a mesh by a region of similar semantics (but different geometry) within a mesh database. For that, we introduce a selection tool in a space of semantic descriptors that co-selects areas of similar semantics within the database. Moreover, this tool can be used for part-based retrieval across the database. Then, we show how semantic information improves the assembly process. This allows for modeling complex meshes from a coarse geometry and a database of more detailed meshes, and makes modeling accessible to the novice user
