Generalized differentiation and fixed points sets behaviors with respect to Fisher convergence

AbstractWe study the stability of a new concept of generalized differentiation for set-valued mappings involving positively homogeneous maps with respect to a variational convergence deriving from the proximal topology. This notion of convergence, well-suited for set-valued mappings, allows us as well to establish the continuous dependence of fixed points sets of set-valued contractions

Convergence de Fisher et H-différentiabilité des applications multivoques

Dans cette thèse nous présentons dans un premier temps une nouvelle notion de différentiabilité généralisée pour les applications multivoques, faisant intervenir des applications positivement homogènes: la H-différentiabilité. Nous étudions la stabilité de cette notion en utilisant la convergence de Fischer, d'abord dédiée aux ensembles mais que nous avons adaptée aux applications multivoques. Nous nous intéressons ensuite à l'étude de la dépendance continue des ensembles de points fixes d'une application multivoque contractante par rapport aux données. Finalement nous analysons la convergence d'une méthode d'approximations successives de type forward-backward splitting, des zéros de la somme de deux opérateurs multivoques non monotones, jouissants notamment de propriétés de pseudo H-différentiabilitéIn this thesis we present at first a new concept of generalized differentiation for setvalued mappings, involving positively homogeneous applications: the H-differentiability. We study the stability of this notion by using Fischer convergence,firstly dedicated to sets but which we have adapted to set-valued mappings. We establish the continuous dependence of fixed points sets of set-valued contraction and finally we study the convergence of a forward-backward splitting method for approximating the zeros of the sum of two non-monotone set-valued mappings, notably using properties of pseudo H-differentiability.POINTE A PITRE-BU (971202101) / SudocSudocFranceF

Localization and speciation of Zn in mycorrihizd roots by μSXRF and μEXAFS.

Mycorrhizae are symbiotic associations between soil fungi and plant roots, which enhance mineral nutrition for the plant, and might play an important role in metals acquisition and accumulation. The processes allowing metals mobilization in the soil, absorption by the root and/or the fungus, transfer or bioaccumulation are still poorly understood. However, the properties of mycorrhizal fungi could be used for phytoremediation, a soft technique using plants for the clean-up of metal polluted soils. In this work, mycorrhized roots of tomato plants grown in a Zn-contaminated soil were investigated. The distribution of metals and the speciation of Zn were studied at the micron scale using micro synchrotron-based X-ray fluorescence (μSXRF) and micro X-ray absorption spectroscopy (μEXAFS). Zn associated to the root was Zn malate and/or Zn citrate, and Zn associated to the fungus was Zn phyllosilicate. This study illustrates the great potential of X-ray microbeams for the study of biological samples containing various amounts of metals

Zn speciation in the organic horizon of a contaminated soil by micro X-ray fluorescence, micro and powder EXAFS spectroscopy and isotopic dilution.

Soils which have been acutely contaminated by heavy-metals show distinct characteristics, such as colonization by metal-tolerant plant species and topsoil enrichment in weakly degraded plant debris because biodegradation processes are strongly inhibited by contamination. Such an organic topsoil, located downwind of an active zinc smelter and extremely rich in Zn (~ 2%, dry weight), was investigated by X-ray diffraction (XRD), synchrotron-based X-ray microfluorescence (μSXRF), and powder and micro extended X-ray absorption fine structure (EXAFS) spectroscopy for Zn speciation, and by isotopic dilution for Zn lability. EXAFS spectra recorded on size fractions and on selected spots of thin sections were analyzed by principal component analysis (PCA) and linear combination fits (LCFs). Although Zn primary minerals (franklinite, sphalerite and willemite) are still present (~ 15% of total Zn) in the bulk soil, Zn was found to be predominantly speciated as Zn-organic matter complexes (~ 45%), outer-sphere complexes (~ 20%), Zn-sorbed phosphate (~ 10%) and Znsorbed iron oxyhydroxides (~ 10%). The bioaccumulated Zn fraction is likely complexed to soil organic matter after the plants' death. The proportion of labile Zn ranges from 54 to 92%, depending on the soil fraction, in agreement with the high proportion of organically-bound Zn. Despite its marked lability, Zn seems to be retained in the topsoil thanks to the huge content of organic matter, which confers to this horizon a high sorption capacity. The speciation of Zn in this organic soil horizon is compared with that found in other types of soils

Le lycée Robert-Doisneau à Vaulx-en-Velin : Portrait d'un établissement en «construction»

Das Robert Doisneau-Gymnasium in Vaulx-en-Velin Gleich nach seiner Eröffnung inmitten einer großen Sozialbau-Siedlung suchte das Gymnasium von Vaulx-en-Velin einen Namen, der an humanistische Werte anklingen sollte, und verfiel schließlich auf Robert Doisneau, den kürzlich verstorbenen, populären Photographen. Der Bau des Gymnasiums war von der Kommune seit langem gefordert worden und wurde schließlich genehmigt, nachdem 1990 die «Unruhen» in den französischen Vorstädten ein enormes Echo in den Medien ausgelöst hatten. In dieser krachneuen Lehranstalt verwahren sich Unterrichtende wie Lernende gegen jede Stigmatisierung zum Ghetto-Gymnasium.Lycée Robert-Doisneau in Vaulx-en-Velin As soon as it opened its doors in the heart of a large social housing complex, the new secondary school in Vaulx-en-Velin was in search of a name symbolizing humanist values. It eventually decided on Robert Doisneau, a popular photographer who passed away recently. This urban area facility is the result of a long-standing local request that was suddenly clarified and satisfied due to media coverage of the «urban riots» in 1990. Teachers and students in this brand new public establishment are standing up for themselves against any and all attempts at its being stigmatized as a ghetto school.Immédiatement après son ouverture au cœur d'un grand ensemble d'habitat social, le nouveau lycée de Vaulx-en-Velin a cherché un nom pour signifier les valeurs d'humanisme et désigner finalement Robert Doisneau, photographe populaire récemment disparu. Cet équipement d'agglomération est le résultat d'une longue demande locale brusquement précisée et satisfaite à la faveur de la médiatisation des «émeutes urbaines» de 1990. Dans cet établissement public étincelant de neuf, enseignants et élèves se défendent contre toute tentative de stigmatisation en lycée-ghetto.El liceo Doisneau en Vaulx-en-Velin Justo después de su apertura en el centro de un gran conjunto de vivienda social, el nuevo liceo de Vaulx-en-Velin buscó un nombre para significar los valores humanistas y escogió finalmente el de Robert Doisneau, fotógrafo popular recientemente desaparecido. Este equipamiento de aglomeración es el resultado de una antigua reivindicación local, bruscamente precisada y satisfecha aprovechando de la mediatización de los «motines urbanos» de 1990. En este nuevo y deslumbrante establecimiento público, profesores y alumnos se niegan a toda tentativa de estigmatización como liceo-ghetto.Geoffroy Géraldine. Le lycée Robert-Doisneau à Vaulx-en-Velin : Portrait d'un établissement en «construction». In: Les Annales de la recherche urbaine, N°75, 1997. L’école dans la ville. pp. 120-131

Pour une approche décomplexée de l’IA

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La réalité augmentée en bibliothèque

[Reprise d'un billet publié le 22 mai 2018 sur le blog HTTBU par Géraldine Geoffroy] La réalité augmentée en bibliothèque : quelques applications Réalité virtuelle, réalité augmentée, réalité mixte… autant de termes qui passent petit à petit dans le langage courant, autant d’applications pratiques de ces concepts qui sortent de la confidentialité et intègrent de plus en plus notre quotidien. Or il se trouve qu’il en va de ces technologies comme de la plupart des outils de développement (web)..

UNE GRANDE ÉCOLE EN BANLIEUE: L’ÉCOLE NATIONALE DES TRAVAUX PUBLICS DE L’ÉTAT À VAULX-EN-VELIN

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