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Diffusion in Dynamic Networks with Continuous Inputs to Allocate Responsibility
No full textDocuments de travail du Centre d’Économie de la Sorbonne 2025.09 - ISSN : 1955-611X - eISSN : 2968-6687Responsibility in complex networks extends beyond direct actions: players should also bear responsibility for the indirect effects within their supply chains or network. We introduce a novel framework to allocate responsibility for indirect environmental, social, and economic impacts across a dynamic network. Unlike static approaches, our framework accounts for the evolving structure of supply chains, financial systems, and other interconnected systems, where relationships change over time. We use the time-dependent Laplacian matrix to capture how responsibility propagates through the network, revealing a diffusion process that aligns with key axioms of fairness: linearity, efficiency, symmetry, and the independent player property. We show that approximating the responsibility measure preserves these properties, supporting the use of our framework as a rigorous and practical method to allocate responsibility in real-world networks
Pushing the Accuracy Limit of Foundation Neural Network Models with Quantum Monte Carlo Forces and Path Integrals
No full textWe propose an end-to-end integrated strategy to produce highly accurate quantum chemistry (QC) synthetic datasets (energies and forces) aimed at deriving Foundation Machine Learning models for molecular simulation. Starting from Density Functional Theory (DFT), a "Jacob's Ladder" approach leverages computationally-optimized layers of massively GPU-accelerated software with increasing accuracy. Thanks to Exascale, this is the first time that the computationally intensive calculation of Quantum Monte Carlo forces (QMC), and the combination of multi-determinant QMC energies and forces with selected-Configuration Interaction wavefunctions, are computed at such scale at the complete basis-set limit. To bridge the gap between accurate QC and condensed-phase Molecular Dynamics, we leverage transfer learning to improve the DFT-based FeNNix-Bio1 foundation model. The resulting approach is coupled to path integrals adaptive sampling quantum dynamics to perform nanosecond reactive simulations at unprecedented accuracy. These results demonstrate the promise of Exascale to deepen our understanding of the inner machinery of complex biosystems
Multiscale Thermodynamics-Informed Neural Networks (MuTINN) for nonlinear structural computations of recycled thermoplastic composites
No full textInternational audienceFiber-reinforced thermoplastic composites are increasingly valued for their light-weight properties, mechanical performance, and recyclability, yet the recycling process introduces microstructural heterogeneities that degrade their mechanical behavior. To address the challenges from a modeling point of view, this study proposes a Multiscale Thermodynamics-Informed Neural Network (MuTINN) approach to predict the nonlinear, anisotropic response of recycled glass fiber-reinforced polyamide 6 composites, with the primary aim of enabling structural simulations in significantly reduced time compared to traditional FE² approaches. The MuTINN framework integrates thermodynamic principles with artificial neural networks (ANNs) to capture the evolution of internal state variables and Helmholtz free energy, eliminating the need for memory-based networks. Finite element simulations of representativevolume elements (RVEs) under diverse loading conditions are utilized to provide off-line data for the MuTINN. The latter accurately predicts stress, strain, and energy quantities, accounting for the anisotropic and heterogeneous nature of recycled materials. While trained using numerical simulations at 0◦ and 90◦ orientation specimens, the proposed framework succesfully predicts the response for specimens with 45◦ orientation with error in the maximum stress level up to 1.6%. The model is implemented into commercial finite element analysis (FEA) software via a Meta-UMAT framework, allowing efficient macroscale simulations. Validation against experimental data and finite element-based periodic homogenization confirms the framework’s accuracy for structural computations
Systèmes thermiques à sorption solide
No full textInternational audienceSolid sorption chillers and heat pumps represent a range of major componentsfor the rational use of energy. They have already¤ found several development niches:desiccant wheels and low-regeneration-temperature chillers for adsorption,negative-temperature cold production, cold storage for food transport, and thermalstorage for chemical reaction. New products are also highly innovative: atmosphericwater capture, recovery, storage and transport of waste heat. Last but not least, theemergence of MOFs and innovative shaping techniques is opening up new prospects forreducing the weight and volume of these systems, and thus opening up new markets.Les systèmes thermiques a¤ sorption solide représentent une gamme decomposants majeurs pour l’utilisation rationnelle de l’énergie. Ils ont d’ores et déjà¤trouve¤ plusieurs niches de développement : roues dessiccantes et groupesrefroidisseurs de liquide a¤ faible température de régénération pour l’adsorption,production de froid à température négative, stockage de froid pour le transport dedenrées et stockage thermique pour la réaction chimique. De plus, de nouveaux produitssont très innovants : capture d’eau atmosphérique, valorisation, stockage et transport dechaleur fatale. Enfin, l’émergence des MOF ainsi que des mises en forme innovantesouvre de nouvelles perspectives pour réduire le poids et le volume de ces systèmes etentendre ainsi leur march
Qui protège la montagne sacrée ? Entre pressions géopolitiques et économiques et défi écologique, le rôle des ingénieurs à Taïwan
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Conclusion : Trois conceptions de l'efficacité en débat
No full textInternational audiencePlanQui dit efficacité dit évaluationUne conception « managériale » de l’efficacitéLe sens du mot efficacité varie selon les contextes socio-historiques, il relève souvent d’un point de vue externe à l’individu en lien avec des enjeux d’évaluation et de contrôle du travailVersus, une conception « professionnelle et humaniste » de l’efficacitéLe sens du mot efficacité est alors défini du point de vue de l’individu comme la possibilité de se construire comme un professionnel capable et dignePour une conception « collective ou négociée » de l’efficacitéRéconcilier ces deux conceptions en élaborant ensemble les repères collectifs de l’efficacité pour augmenter le pouvoir d’agir de tou
Éditorial : le vécu de l'expérience doctorale face aux transformations du doctorat : diversification des profils et professionnalisation
No full textInternational audienceCe numéro spécial sur le vécu de l’expérience doctorale face aux transformations du doctorat est traité par des chercheurs de différents espaces de la francophonie : Belgique, France, Canada et Luxembourg. Nous savons que les parcours doctoraux sont extrêmement diversifiés en fonction des spécificités disciplinaires, des modes de financement du doctorat, de l’encadrement doctoral reçu, de la plus ou moins longue expérience qui précède l’entrée en thèse, des perspectives professionnelles des doctorants (Millet et Annoot, 2017; Skakni, 2018). Le vécu de l’expérience doctorale est également sujet à variation tout au long d’un parcours doctoral. [...
Construction Process of the Langue de Barbarie in Senegal, Based on the Identification and Quantification of Fluvial and Marine Sources: Application of the New ELSA Geochemical Methodology
No full textInternational audienceThe Langue de Barbarie (LDB), located off the coast of Saint-Louis (Senegal), is a rapidly evolving sand spit. To understand how its formation, it is crucial to define the continental or marine origin of the sediments and to pinpoint their sources. An emerging methodology (Elemental composition of Sediment frActions—ELSA) based on particle geochemical analysis of each sediment grain class was used. Different geochemical markers were used: Zr/Ti for the fine fractions (100–160 μm) rich in heavy minerals, Si/Zr for the medium fractions (200–315 μm) dominated by quartz and Ca, which characterizes marineshell inputs, for the coarse fractions (400–630 μm). Compositional end-members were defined and used to calculate the proportions of continental and marine sources for sediments from each of seven LDB stations and five reference stations. Our study proposes a three-phase construction sequence. The initial phase (construction of the tip) was dominated by river inputs, the second was dominated by the Senegal River, the amplification of marine inputs and longshore drift, whereas the third phase (maturation) was dominated by longshore drift linked to frequent and strong oblique swells. Our results confirmthe importance of the latter processes during the elongation of the spit
From co-location to co-presence at work: building collectives in hybrid workplaces
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Embedding Mo 2 O 2 S 2 ‐Bis(thiosemicarbazone) Complexes Into Polyurethane Matrices: Synthesis and Characterization
No full textInternational audience[Mo V 2 O 2 S 2 ] 2+ ‐based thiosemicarbazone complexes are an interesting family of molecules, which can display various biological properties. However, in order to develop applications, it is necessary to shape this type of complex, in polymer matrices for example. In this article, we report the synthesis of a series of 16 composite materials corresponding to the incorporation of [(Mo 2 O 2 S 2 ) n (L 1–6 ) n ] ( n = 1, 2) bis‐thiosemicarbazones complexes in a polyurethane matrix. These composites are described as [Mo V 2 O 2 S 2 ] 2+ –thiosemicarbazone‐based polyurethanes and denoted PU‐[(Mo 2 O 2 S 2 ) n (L 1–6 ) n ] ( n = 1, 2). Various [(Mo 2 O 2 S 2 ) n (L 1–6 ) n ]–bis‐thiosemicarbazone complexes were used including di‐ or tetranuclear structures with different numbers of uncoordinated amino and hydroxyl groups and alkyl substituents on the ligands L i ( i = 1–6). The composite materials obtained are studied in depth by SEM–EDX, FT‐IR, NMR, TGA, and DSC to understand the organization of polymer chains and complexes within the materials and to highlight certain changes in physical properties induced by the nature of the complexes. The complexes are homogeneously distributed within the polymer matrices and the embedding of these complexes seems to be mainly due to hydrogen bonding networks. Nevertheless, these H‐bond networks are strong enough to provoke modification of the physical properties of the polymers in terms of thermal stability or flexibility