HAL Portal de Univ. Gustave Eiffel
Not a member yet
72847 research outputs found
Sort by
The key role of motorized two-wheelers in boosting the earnings of on-demand delivery workers in Paris
No full textInternational audienceIn France, earnings from delivery workers involved in on-demand instant delivery are not well known. Using data from two waves of a survey conducted in Paris with instant delivery workers, this research presents the interactions between types of delivery gigs, operations and vehicles that lead to differences in income earned from delivery. The results show that the highest incomes are found among delivery workers with the longest service and who work for multiple delivery platforms. More importantly, using a motorized two-wheeler instead of a bicycle, e-bicycle, or scooter is key. It seems to be the best way to ensure a good level of earnings for on-demand instant delivery workers. However, there are legal and environmental dilemmas. Primarily, French law mandates that freelance delivery drivers obtain a specific license before utilizing mopeds for delivery purposes, a license that most of them do not have. Moreover, the energy consumption of mopeds is higher than that of bicycles and electric scooters by a factor of twenty, presenting significant environmental concerns
Metric extrapolation in the Wasserstein space
No full textInternational audienceIn this article we study a variational problem providing a way to extend for all times minimizing geodesics connecting two given probability measures, in the Wasserstein space. This is simply obtained by allowing for negative coefficients in the classical variational characterization of Wasserstein barycenters. We show that this problem admits two equivalent convex formulations: the first can be seen as a particular instance of Toland duality and the second is a barycentric optimal transport problem. We propose an efficient numerical scheme to solve the latter formulation based on entropic regularization and a variant of Sinkhorn algorithm
Compte-rendu de E. Durand, L’envers des fripes. Les vêtements dans les plis de la mondialisation, Paris, Premier parallèle, 2024
No full textInternational audienceCompte-rendu de E. Durand, L’envers des fripes. Les vêtements dans les plis de la mondialisation, Paris, Premier parallèle, 2024
Avec le télétravail et les achats en ligne, quelles évolutions des mobilités?
No full textInternational audienc
Computation of toroidal Schnyder woods made simple and fast: from theory to practice
No full textWe consider the problem of computing Schnyder woods for graphs embedded on the torus. We design simple linear-time algorithms based on canonical orderings that compute toroidal Schnyder woods for simple toroidal triangulations. The Schnyder woods computed by one of our algorithm are crossing and satisfy an additional structural property: at least two of the mono-chromatic components of the Schnyder wood are connected. We also exhibit experimental results empirically confirming three conjectures involving the structure of toroidal and higher genus Schnyder woods.</div
Thermal noise reduction in ion-beam sputtered HfO2:Ta2O5 thin films via high-temperature treatment
No full textInternational audienc
Study on the Effects of a Low Amount of Non-plastic Fines on Soil Liquefaction by Dynamic Centrifuge Modeling
No full textInternational audienceThis paper presents a new experimental campaign investigating the influence of non-plastic fines on soil liquefaction behavior by dynamic centrifuge model tests. Non-plastic fines C500 were added to clean Hostun HN31 sand based on the constant host sand matrix concept. The characteristics and behavior of both clean sand and sand with fines are analyzed, including CPT resistance, small strain shear modulus, liquefaction resistance, post-shake re-consolidation, and model surface settlement. The low quantity of non-plastic fines has very limited effects on the CPT resistance and slightly increases the small strain shear modulus. In terms of liquefaction resistance, the presence of non-plastic fines has a considerable impact on medium-dense sand. For the medium dense case, the presence of 5% non-plastic fines increases the liquefaction resistance. However, when subjected to the successive shaking, the medium dense sand mixture became less resistant to liquefaction. For the case of dense sand, the presence of non-plastic fines on the liquefaction resistance of is not pronounced. For both medium-dense and dense sands, the presence of non-plastic fines significantly reduces the re-consolidation coefficient and increases surface settlement
Proceedings du colloque PROVIRCAP : Réformer le capitalisme de l'intérieur?
No full textInternational audienceThese Proceedings bring together the presentations' abstracts and discussions of the symposium “Reforming capitalism from within?” held on the Jourdan campus of the École Normale Supérieure (Paris) on May 30 and 31, 2024, at the initiative of the ANR PROVIRCAP team - Professionals of the Virtue of Capitalism: Corporate social responsibility through the lens of its managers (2021-2025). Over two days, 46 papers were presented in 12 parallel thematic sessions, followed by closing remarks and plenary debates.The PROVIRCAP research program rests on the hypothesis that it is heuristic to bring together, confront and compare a variety of collective mobilizations and professional efforts rooted in the business world and geared towards what we have termed the moral reform of capitalism, now often associated with the categories of CSR (corporate social responsibility), “responsible capitalism”, “good capitalism”, “impact” or “ESG” (Environment, Social, Governance).This symposium provided an opportunity for scholars specializing in various projects for the moral reform of capitalism to engage in a dialogue, revealing convergences, articulations, contrasts and boundaries.Ces Proceedings rassemblent les résumés des communications ainsi que les textes des discussions du colloque « Réformer le capitalisme de l’intérieur ? » qui s’est tenu sur le campus Jourdan de l’ENS les 30 et 31 mai 2024, à l’initiative de l’équipe ANR PROVIRCAP – Professionnel·les de la vertu du capitalisme : la RSE saisie par ses managers (2021-2025). En deux jours, 46 communications ont été présentées dans 12 sessions thématiques parallèles, ponctuées de conclusions et de débats en plénière.L’hypothèse au cœur du programme de recherche PROVIRCAP est qu’il est heuristique de rapprocher, confronter et comparer une variété de mobilisations collectives et d’investissements professionnels qui sont inscrits dans le monde marchand et tournés vers ce que nous avons appelé la réforme morale du capitalisme, aujourd’hui souvent rattachées aux catégories de RSE (responsabilité sociale des entreprises), de « capitalisme responsable », de « good capitalism », d’« impact » ou encore d’« ESG » (Environnement, Social, Gouvernance).Ce colloque a permis de faire dialoguer les spécialistes de ces différents projets de réforme morale de l’économie, pour mettre au jour des convergences, des articulations, des contrastes et des frontières
CREMSA: Compressed indexing of (ultra) large multiple sequence alignments
No full textInternational audienceRecent viral outbreaks motivate the systematic collection of pathogenic genomesin order to accelerate their study and monitor the apparition/spread of variants. Due to their limited length and temporal proximity of their sequencing, viral genomes are usually organized, and analyzed as oversized Multiple Sequence Alignments (MSAs). Such MSAs are largely ungapped, and mostly homogeneous on a column-wise level but not at a sequential level due to local variations, hindering the performances of sequential compression algorithms. In order to enable an efficient handling of MSAs, including subsequent statistical analyses, we introduce CREMSA (Column-wise Run-length Encoding for Multiple Sequence Alignments), a new index that builds on sparse bitvector representations to compress an existing or streamed MSA, all the while allowing for an expressive set of accelerated requests to query the alignment without prior decompression. Using CREMSA, a 65GB MSA consisting of 1.9M SARS-CoV 2 genomes could be compressed into 22MB using less than half a gigabyte of main memory, while executing access requests in the order of 100ns. Such a speed up enables a comprehensive analysis of covariation over this very large MSA. We further assess the impact of the sequence ordering on the compressibility of MSAs and propose a resorting strategy that, despite the proven NP-hardness of an optimal sort, induces greatly increased compression ratios at a marginal computational cost