Une informalité bien ordonnée ? La conversation académique sur Twitter

in Tracés. Revue de sciences humaines. (2021), (#21), 65-84

Twitter and social media do not have a good reputation. However, this reputation does not correspond, or only partly corresponds, to the experience of many researchers. Based on a corpus of tweets, we ... [more ▼]

Twitter and social media do not have a good reputation. However, this reputation does not correspond, or only partly corresponds, to the experience of many researchers. Based on a corpus of tweets, we argue in this article that academic Twitter reflects the material conditions of research in France, allows for greater visibility of researchers and consequently for the formation of atypical networks that does not occur in the more traditional places of academic socialization, all in a form of a “well-ordered” informality, partly constrained by the hierarchies of higher education and research. [less ▲]

Young People and Covid-19 II: Développements de 2020 à 2021, disposition à se faire vacciner et répercussions de la pandémie Résultats provisoires d’un sondage représentatif auprès d’adolescents et de jeunes adultes au Luxembourg

Report (2021)

INVESTIGATION OF POINTNET FOR SEMANTIC SEGMENTATION OF LARGE-SCALE OUTDOOR POINT CLOUDS

Scientific journal (2021)

Semantic segmentation of point clouds is indispensable for 3D scene understanding. Point clouds have credibility for capturing geometry of objects including shape, size, and orientation. Deep learning (DL ... [more ▼]

Semantic segmentation of point clouds is indispensable for 3D scene understanding. Point clouds have credibility for capturing geometry of objects including shape, size, and orientation. Deep learning (DL) has been recognized as the most successful approach for image semantic segmentation. Applied to point clouds, performance of the many DL algorithms degrades, because point clouds are often sparse and have irregular data format. As a result, point clouds are regularly first transformed into voxel grids or image collections. PointNet was the first promising algorithm that feeds point clouds directly into the DL architecture. Although PointNet achieved remarkable performance on indoor point clouds, its performance has not been extensively studied in large-scale outdoor point clouds. So far, we know, no study on large-scale aerial point clouds investigates the sensitivity of the hyper-parameters used in the PointNet. This paper evaluates PointNet’s performance for semantic segmentation through three large-scale Airborne Laser Scanning (ALS) point clouds of urban environments. Reported results show that PointNet has potential in large-scale outdoor scene semantic segmentation. A remarkable limitation of PointNet is that it does not consider local structure induced by the metric space made by its local neighbors. Experiments exhibit PointNet is expressively sensitive to the hyper-parameters like batch-size, block partition and the number of points in a block. For an ALS dataset, we get significant difference between overall accuracies of 67.5% and 72.8%, for the block sizes of 5m×5m and 10m×10m, respectively. Results also discover that the performance of PointNet depends on the selection of input vectors. [less ▲]

Quantitative volatile organic compound sensing with liquid crystal core fibers

in Cell Reports Physical Science (2021), 2(12), 100661

Polymer fibers with liquid crystals (LCs) in the core have potential as autonomous sensors of airborne volatile organic compounds (VOCs), with a high surface-to-volume ratio enabling fast and sensi- tive ... [more ▼]

Polymer fibers with liquid crystals (LCs) in the core have potential as autonomous sensors of airborne volatile organic compounds (VOCs), with a high surface-to-volume ratio enabling fast and sensi- tive response and an attractive non-woven textile form factor. We demonstrate their ability to continuously and quantitatively mea- sure the concentration of toluene, cyclohexane, and isopropanol as representative VOCs, via the impact of each VOC on the LC bire- fringence. The response is fully reversible and repeatable over several cycles, the response time can be as low as seconds, and high sensitivity is achieved when the operating temperature is near the LC-isotropic transition temperature. We propose that a broad operating temperature range can be realized by combining fi- bers with different LC mixtures, yielding autonomous VOC sensors suitable for integration in apparel or in furniture that can compete with existing consumer-grade electronic VOC sensors in terms of sensitivity and response speed. [less ▲]

Young People and Covid-19 II: Desenvolvimentos de 2020 a 2021, disposição para a vacinação e impacto da pandemia. Resultados preliminares de um inquérito representativo de jovens e jovens adultos no Luxemburgo

Report (2021)

Optimal power and efficiency of odd engines

in Physical Review. E (2021)

Odd materials feature antisymmetric response to perturbations. This anomalous property can stem from the nonequilibrium activity of their components, which is sustained by an external energy supply. These ... [more ▼]

Odd materials feature antisymmetric response to perturbations. This anomalous property can stem from the nonequilibrium activity of their components, which is sustained by an external energy supply. These materials open the door to designing innovative engines which extract work by applying cyclic deformations, without any equivalent in equilibrium. Here, we reveal that the efficiency of such energy conversion, from local activity to macroscopic work, can be arbitrarily close to unity when the cycles of deformation are properly designed. We illustrate these principles in some canonical viscoelastic materials, which leads us to identify strategies for optimizing power and efficiency according to material properties and to delineate guidelines for the design of more complex odd engines. [less ▲]

Discussion of "Dynamic Asset (Mis)Pricing: Build-up vs. Resolution Anomalies" by Jules Van Binsbergen et al.

Scientific Conference (2021, December 20)

La construction de la politique d’immigration de l’union européenne entre 2009 et 2019 : vers un modèle commun ? Etude de cas : l’Espagne, la Grèce et l’ Italie

Doctoral thesis (2021)

The communautarisation of migration policies is a slow process. EU member states have often shown reluctance to share their sovereignty in this sensitive field throughout European integration. The entry ... [more ▼]

The communautarisation of migration policies is a slow process. EU member states have often shown reluctance to share their sovereignty in this sensitive field throughout European integration. The entry into force of the Lisbon treaty - supposed to enhance migration policies integration - occurred simultaneously with the euro-zone financial crisis and was followed by a so-called ‘migration crisis. Which political developments finally occurred at the supranational level? Which decision-making methods were used? Did they comply with the previous EU member states’ commitments of building a common migration policy? Greece, Spain, and Italy handled most of the migrants’ flows reception which demonstrated a lack of solidarity among EU member states. Considering this lack of solidarity, have these three states’ decisions converged towards EU norms and requests? First, we assumed that a slowdown in the integration process would have taken place following the migration crisis. Then, we affirmed that the three States would pursue national interests by developing strategies within the institutional framework of the European Union. Finally, we have stated that these strategies could lead to the emergence of national models with elements of convergence. In order to verify these hypotheses, we focused on the EU and national legislative developments, the degree of states' compliance with EU standards as well as the position of the states held during the negotiation taking place at the supranational level. We have therefore used primary sources (institutional reports, legislations, statistics, interviews contents, etc.) and secondary academic sources (results of research projects, articles, etc.) Ten years after the entry into force of the Lisbon treaty, our findings confirmed that building a common European migration policy is a difficult goal to achieve at a supranational level and hindered - in combination with other factors - the Europeanization process. Thus the intergovernmentalist theory has proven to be valid for analyzing European integration as well as the Europeanization in Spain, Greece and Italy of immigration policies between 2009 and 2019. Thus, the neo-functionalist logic which until then dominated the development of the economic and monetary policies of the European Union has been partially challenged when it comes to migration policies. As for the neo-institutional historical and rational choice approaches, they have proved relevant for the study of the construction of European immigration policy whose result consists of both existing common commitments (path dependency) and national interests. [less ▲]

Für andere sprechen. Die Politik der Übersetzung in The Interpreter (2005) und Arrival (2016)

in Gradinari, Irina; Ritzer, Ivo (Eds.) Genre und Race. Mediale Interdependenzen von Ästhetik und Politik (2021)

In politischen Fiktionen des gegenwärtigen Hollywood-Kinos geraten ‚symbolische‘ und ‚deskriptive‘ Repräsentation zunehmend miteinander in Konflikt. Der Anspruch auf deskriptive Repräsentation, demzufolge ... [more ▼]

In politischen Fiktionen des gegenwärtigen Hollywood-Kinos geraten ‚symbolische‘ und ‚deskriptive‘ Repräsentation zunehmend miteinander in Konflikt. Der Anspruch auf deskriptive Repräsentation, demzufolge z.B. ethnisch markierte Minoritäten durch Personen vertreten werden sollen, die diesen Minoritäten selbst angehören, führt insbesondere in solchen Genres und Filmen zu Komplikationen, in denen die Problematik politischer Repräsentation zentrales Thema ist. Der Aufsatz konzentriert sich auf die Figur der weißen Übersetzerin, die in Sydney Pollacks The Interpreter und Denis Villeneuves Arrival als Vermittlerin in diesem Konflikt Einsatz findet. Unter Verwendung unterschiedlicher Genre-Elemente – des Politthrillers und des alien invasion movies – arbeiten diese Werke an einer Ethik der Übersetzung, die repräsentative Gewalt zu überwinden sucht, indem sie die für jede Repräsentation konstitutive Distanz zwischen Repräsentant*innen und Repräsentierten gerade betont, anstatt sie zu bekämpfen. [less ▲]

Old Monarchies in Old Europe. Anything new? An Appetizer, with Special Reference to Liechtenstein

E-print/Working paper (2021)