1,285 research outputs found

    A note on the spectrum of Lipschitz operators and composition operators on Lipschitz spaces

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    Fix a metric space MM and let Lip0(M)\mathrm{Lip}_0(M) be the Banach space of complex-valued Lipschitz functions defined on MM. A weighted composition operator on Lip0(M)\mathrm{Lip}_0(M) is an operator of the kind wCf:gwgfwC_f : g \mapsto w \cdot g \circ f, where w:MCw : M \to \mathbb C and f:MMf: M \to M are any map. When such an operator is bounded, it is actually the adjoint operator of a so-called weighted Lipschitz operator wf^w\widehat{f} acting on the Lipschitz-free space F(M)\mathcal F(M). In this note, we study the spectrum of such operators, with a special emphasize when they are compact. Notably, we obtain a precise description in the non-weighted w1w \equiv 1 case: the spectrum is finite and made of roots of unity

    La nostalgia en la producción urbana: La defensa de barrios en Santiago de Chile

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    The neoliberal city has recently become a central subject of study in urban studies. One of the aspects analyzed is the extension of the pressure exerted by the real estate market and urban renewal, an activity based in the constant destruction and reconstruction of cities. However, there are few studies focused on how these processes are experienced and perceived by dwellers within the context of their daily lives. Through the study of social conflicts against specific urban projects in defense of neighborhoods in Santiago Centro, Chile, this paper explores the nostalgia due to urban changes in the past. This research is based on an ethnographic field work conducted from 2014 to 2015 with groups of dwellers involved in the defense and promotion of the heritage value of the Matta Sur neighborhood. The aim of this paper is to analyze and question the use, presence and emergence of nostalgia within the space dimension and its current socio-cultural role in the production of cities.En los últimos años, la ciudad neoliberal se ha transformado en un tema central en los estudios urbanos. Uno de los aspectos analizado es la extensión de la presión inmobiliaria acompañada por la renovación urbana que consiste en destruir y reconstruir de manera permanente la ciudad. Sin embargo, son escasos los estudios que se interesan en la manera en que esos procesos son vividos y percibidos en la cotidianidad por sus habitantes, para desde ahí establecer un punto de vista crítico. Partiendo de esta constatación, el artículo propone interrogar la nostalgia gatillada por los cambios urbanos a partir del estudio de la movilización de habitantes contra los proyectos inmobiliarios y por la defensa de su barrio en Santiago Centro (Chile). El artículo se basa en un trabajo de campo de corte etnográfico realizado en 2014 y 2015 con grupos de habitantes involucrados en la defensa y la revalorización patrimonial del barrio Matta Sur. Con este trabajo se busca analizar y cuestionar la presencia y la materialización de la nostalgia en el espacio y sus usos y funciones socio-culturales actuales en la producción de la ciudad

    Révolution numérique dans le bâtiment: : analyse des gains escomptés par la diffusion des outils numériques (BIM et maquette numérique) dans le secteur du bâtiment.

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    Afin de répondre aux grands enjeux du secteur du bâtiment (qualité, productivité, performance énergétique), les acteurs de cette filière misent aujourd’hui sur les technologies de l’information et de la communication. Le BIM («Building Information Modeling»), déjà adopté dans de nombreux pays étrangers, semble un outil très prometteur. Face à cette compétitivité internationale, le gouvernement français s'est emparé du sujet BIM, en créant fin 2014 le Plan de Transition du Numérique dans le Bâtiment (PTNB). Aussi se posent diverses questions afin de permettre le déploiement du BIM à l'échelle nationale. Comment diffuser le BIM en France? Quels sont les gains et freins escomptés par sa diffusion? Quel est le rôle des pouvoirs publics

    Multi-resonant absorption in ultra-thin silicon solar cells with metallic nanowires

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    International audienceWe propose a design to confine light absorption in flat and ultra-thin amorphous silicon solar cells with a one-dimensional silver grating embedded in the front window of the cell.We show numerically that multi-resonant light trapping is achieved in both TE and TM polarizations. Each resonance is analyzed in detail and modeled by Fabry-Perot resonances or guided modes via grating coupling. This approach is generalized to a complete amorphous silicon solar cell, with the additional degrees of freedom provided by the buffer layers. These results could guide the design of resonant structures for optimized ultra-thin solar cells

    Les ambiguïtés et les limites de la construction patrimoniale d’une industrie en activité. Le cas de la Centrale thermique de Cordemais

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    À partir de l’exemple de la centrale thermique de Cordemais, l’article interroge les limites de la construction patrimoniale et de son extension aux industries en activité. Sortant du référentiel patrimonial traditionnel par son usage, cet équipement producteur d’électricité tend pourtant à être interrogé dans ses dimensions patrimoniales. A partir d’entretiens semi-directifs auprès d’acteurs territoriaux de l’estuaire de la Loire, nous examinons les chainons explicatifs de cette désignation patrimoniale et de ses limites.With the example of the coal plant of Cordemais, the article deals about the limits of the extension of the heritage production to manufactories activities. Out of the traditional heritage frame because of his use, this energy producer equipment, however, is questioned for his heritage dimension. With the collection of semi-structured interviews to the local actors of the Loire estuary, we examine explanatories factors of this heritage nomination. Moreover, the notion of heritage, his evolution and his boundaries are questioned by this example

    Hot Carrier Solar Cell: From Simulation to Devices

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    International audienceSingle junction III-V heterostructures based devices could overtake the Shockley-Queisser limit if thermalisation of photogenerated carriers can be strongly limited as in the hot carrier solar cell concept. Previous modelling and experiments have shown the interest of Multiple Quantum Wells heterostructures in the antimonide system and the importance of very thin structures. In this paper we report new data on the thermalisation rates in antimonide and phosphide heterostructures measured at ambient temperature. For the first time electrical control of hot carrier population is performed on hot carrier heterostructures device

    Colonization of the Americas, 'Little Ice Age' climate, and bomb-produced carbon: their role in defining the Anthropocene

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    A recently published analysis by Lewis and Maslin (Lewis SL and Maslin MA (2015) Defining the Anthropocene. Nature 519: 171–180) has identified two new potential horizons for the Holocene−Anthropocene boundary: 1610 (associated with European colonization of the Americas), or 1964 (the peak of the excess radiocarbon signal arising from atom bomb tests). We discuss both of these novel suggestions, and consider that there is insufficient stratigraphic basis for the former, whereas placing the latter at the peak of the signal rather than at its inception does not follow normal stratigraphical practice. Wherever the boundary is eventually placed, it should be optimized to reflect stratigraphical evidence with the least possible ambiguity

    UD-SV : Plateforme d’exploration de données urbaines à n-dimensions — Espace, Temps, Thématiques

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    Cet article présente la plateforme UD-SV (Urban Data Services and Visualization) développée au laboratoire LIRIS. UD-SV regroupe un ensemble de composants s’appuyant sur du code ouvert permettant de stocker, de visualiser, d’interagir, de naviguer et d’interroger des modèles de villes 2D et 3D, mais aussi temporels. UD-SV permet d’intégrer des données spatiales, temporelles et sémantiques pour l’analyse urbaine et pour la compréhension de son évolution. Nous décrivons l’architecture, la conception, le développement et nous exemplifions avec quelques processus de calcul de UD-SV

    Neurodevelopmental and Epilepsy Phenotypes in Individuals With Missense Variants in the Voltage-Sensing and Pore Domains of KCNH5

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    Background and Objectives KCNH5 encodes the voltage-gated potassium channel EAG2/Kv10.2. We aimed to delineate the neurodevelopmental and epilepsy phenotypic spectrum associated with de novo KCNH5 variants.Methods We screened 893 individuals with developmental and epileptic encephalopathies for KCNH5 variants using targeted or exome sequencing. Additional individuals with KCNH5 variants were identified through an international collaboration. Clinical history, EEG, and imaging data were analyzed; seizure types and epilepsy syndromes were classified. We included 3 previously published individuals including additional phenotypic details.Results We report a cohort of 17 patients, including 9 with a recurrent de novo missense variant p.Arg327His, 4 with a recurrent missense variant p.Arg333His, and 4 additional novel missense variants. All variants were located in or near the functionally critical voltage-sensing or pore domains, absent in the general population, and classified as pathogenic or likely pathogenic using the American College of Medical Genetics and Genomics criteria. All individuals presented with epilepsy with a median seizure onset at 6 months. They had a wide range of seizure types, including focal and generalized seizures. Cognitive outcomes ranged from normal intellect to profound impairment. Individuals with the recurrent p.Arg333His variant had a self-limited drug-responsive focal or generalized epilepsy and normal intellect, whereas the recurrent p.Arg327His variant was associated with infantile-onset DEE. Two individuals with variants in the pore domain were more severely affected, with a neonatal-onset movement disorder, early-infantile DEE, profound disability, and childhood death.Discussion We describe a cohort of 17 individuals with pathogenic or likely pathogenic missense variants in the voltage-sensing and pore domains of Kv10.2, including 14 previously unreported individuals. We present evidence for a putative emerging genotype-phenotype correlation with a spectrum of epilepsy and cognitive outcomes. Overall, we expand the role of EAG proteins in human disease and establish KCNH5 as implicated in a spectrum of neurodevelopmental disorders and epilepsy.</p

    OGLE-2019-BLG-0825: Constraints on the Source System and Effect on Binary-lens Parameters arising from a Five Day Xallarap Effect in a Candidate Planetary Microlensing Event

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    We present an analysis of microlensing event OGLE-2019-BLG-0825. This event was identified as a planetary candidate by preliminary modeling. We find that significant residuals from the best-fit static binary-lens model exist and a xallarap effect can fit the residuals very well and significantly improves χ2\chi^2 values. On the other hand, by including the xallarap effect in our models, we find that binary-lens parameters like mass-ratio, qq, and separation, ss, cannot be constrained well. However, we also find that the parameters for the source system like the orbital period and semi major axis are consistent between all the models we analyzed. We therefore constrain the properties of the source system better than the properties of the lens system. The source system comprises a G-type main-sequence star orbited by a brown dwarf with a period of P5P\sim5 days. This analysis is the first to demonstrate that the xallarap effect does affect binary-lens parameters in planetary events. It would not be common for the presence or absence of the xallarap effect to affect lens parameters in events with long orbital periods of the source system or events with transits to caustics, but in other cases, such as this event, the xallarap effect can affect binary-lens parameters.Comment: 19 pages, 7 figures, 6 tables. Accepted by A
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