Scientific Publications of the University of Toulouse II Le Mirail
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Le mystère des pépites vertes (enfin résolu!) – A la source des matières colorantes des sites paléolithiques de la vallée de l’Ardèche
No full textNational audienceLes opérations archéologiques menées dans la vallée de l’Ardèche et du Chassezac ont livré un corpus remarquable de matières colorantes. Parmi elles, plusieurs fragments à inclusions vertes ont été identifiés à la grotte aux Points (30), à l’abri des Pêcheurs (07) et au Mas d’Aiguillon (07). Des matériaux similaires, mais sans inclusions, proviennent d’Huchard et de la Baume d’Oulen (07). L’étude pétrographique révèle une matrice argilo-ferrugineuse fine, associant hématite en feuillets et aluminosilicates, témoignant d’une origine probablement hydrothermale.Ces caractéristiques suggèrent qu’une stratégie de sélection a guidée la collecte des matières colorantes.Deux approches complémentaires ont été menées : la première, analytique (microscopie, Raman, DRX), pour déterminer la nature minéralogique des inclusions vertes ; la seconde, dans le cadre du PCR Pigmentothèque, pour rechercher des affleurements compatibles. Les prospections de 2024 ont abouti à la découverte, d’un affleurement présentant toutes les caractéristiques pétrographiques recherchées : matrice argilo-ferrugineuse et… pépites vertes
On the approximation of the von Neumann equation in the semiclassical limit. Part II : numerical analysis
No full textThis paper is devoted to the numerical analysis of the Hermite spectral method proposed in [14], which provides, in the semiclassical limit, an asymptotic preserving approximation of the von Neumann equation. More precisely, it relies on the use of so-called Weyl's variables to effectively address the stiffness associated to the equation. Then by employing a truncated Hermite expansion of the density operator, we successfully manage this stiffness and provide error estimates by leveraging the propagation of regularity in the exact solution
A literatura nacional brasileira em perspectiva transnacional: debates, conceitos, metodologias
No full textInternational audienceSébastien Rozeaux, brasilianista dedicado ao estudo da história e da história literária brasileiras, concedeu entrevista aos professores Valéria Bezerra, Raquel Campos, Lúcia Granja e Pedro Paulo Catharina, que ora publicamos. O material, transcrito, editado, anotado e revisado por Valéria Bezerra e por Raquel Campos, traz um debate acerca das pesquisas de Sébastien Rozeaux sobre a literatura brasileira oitocentista; do exame sociológico que fez das personalidades implicadas na construção da literatura nacional brasileira; de métodos e conceitos relevantes para o estudo da literatura em uma perspectiva histórica e ainda de suas incursões nos estudos das relações Brasil-Portugal
« Perdus dans Prague sur les pas de Kafka et Hrabal. Une promenade germano-tchèque et décalée au bord de la Vltava. », Préface.
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Modelling children's grammar learning via caregiver feedback in natural conversations
No full textInternational audienceAbstract Many debates in the language acquisition literature have revolved around the role of negative evidence for the acquisition of grammar. The scientific study of this question has not been settled with traditional research methods, given that it requires handling children’s natural social interaction while controlling for the specific role of error-contingent feedback, independent of other types of input. Here, we leveraged computational modelling to test whether there are learning gains in grammar induced by caregivers’ feedback above and beyond learning from input alone. More specifically, we compared language models trained on large corpora of child-directed language to the same models that were additionally fine-tuned through reinforcement learning using a reward model trained to provide caregiver-like feedback. Focusing on clarification requests, we found that fine-tuned models produced more grammatical utterances than baseline models. However, performance on challenging benchmarks of grammar knowledge evaluation did not improve. We showed that these benchmarks could, in principle, be improved through integration of other types of feedback. The broad impact of the current work is to introduce a methodological framework that enables scientists to test many types of feedback, including signals beyond the verbal modality, leading to a more comprehensive evaluation of caregiver feedback in language development. This article is part of the theme issue ‘Mechanisms of learning from social interaction’
Urbanisme (touristique)
No full textL’urbanisme participe à la fabrication de l’image d’une ville (cf. villes touristiques), dont l’ouverture au tourisme contribue à accroître la notoriété. L’aménagement urbain y est convoqué pour produire ou mettre en valeur un décor et une symbolique valorisant l’identité, le renom, l’attrait de la cité et pour y gérer les relations entre habitants et visiteurs
A Scaled Poisson Bayesian Model for Viral Epidemic Monitoring
No full textInternational audienceMonitoring an ongoing epidemic requires accurate, trustworthy and easy to use tools, capable of handling low quality data. Extending existing epidemiological models quantifying the propagation intensity via a time-varying reproduction number, this work proposes a scaled Poisson model, accounting for large intrinsic variability in infection counts. The associated scaled likelihood is plugged into a Bayesian model with a quasi-noninformative prior. A carefully designed Markov Chain Monte Carlo algorithm yields a point estimate and credibility intervals of the reproduction number. The accuracy and robustness to model misspecification and to scale parameter selection of the proposed estimator is demonstrated through intensive numerical experiments on COVID-19 case counts in different countries and during various phases of the pandemic
Laser self-injection locking to fiber Fabry-Perot resonator for frequency comb generation
No full textInternational audienceThis study demonstrates that self-injection locking (SIL) of a distributed feedback (DFB) laser to a high-Q fiber Fabry Perot (FFP) resonator, fabricated with highly nonlinear fiber, allows optical frequency combs (OFC) generation with a laser power as low as 100 mW. More precisely, cavity soliton (CS) regime has been observed in this configuration, along with other types of combs. The laser stabilization using SIL is described. Then the system's behavior is analyzed through modeling the laser's dynamics and comparing the model results to experimental tuning curve measurements. Our findings highlight the critical role of the initial phase of the fiber link between laser and FFP in determining the stability and effectiveness of the locking process. We explore the dynamics of the nonlinear SIL process while varying the laser current, revealing the transition from modulation instability to chaotic comb states, and eventually to soliton formation as the system moves from an effective blue-detuned to an effective red-detuned regime. Notably, the inclusion of self-phase modulation (SPM) in the SIL model predicts accessibility of the narrow soliton existence range. These results highlight the potential of SIL in FFP resonators for low-power, stable OFC generation, offering a promising path forward for practical applications
Palingenesia senatus consultorum. Vol. 1. Senatus consultorum ab anno 509 ad annum 367 a. Chr. n. factorum fragmenta et testimonia quae supersunt
No full textInternational audienceThe present volume is the first part of the palingenesis of the senatus consulta of republican and imperial Rome (509 BC–284 AD). It represents the result of a collaborative research effort that brings ancient sources back to the centre of scientific debate in all their complexity, starting with the way they were created and how they have been handed down through history.It presents the reconstruction and commentary on the decrees of the Roman Senate issued between 509 BC and 367 BC, a significant period marked by the pivotal struggle for equality between the patrician and the plebeian orders. Even in this early phase of Roman legal experience, it is already possible to glimpse the original core of the working mechanisms of the res publica, especially in terms of the dialectic between the Senate and the magistrates, which would also bind the political and institutional development of the subsequent phases
Argumentation semantics based on solid admissibility and preservation of semantic properties
No full textInternational audienceThis paper proposes novel semantics based on solid admissibility, which strengthens Dung’s admissibility by incorporating a condition that an argument requires all defenders for it to be successfully defended. These solid semantics provide a better approach to handling controversial scenarios in Dung’s argumentation framework compared to Dung’s semantics. Specifically, if two arguments are such that one of them indirectly attacks a third argument while the other one indirectly defends the third one, then the three arguments cannot be included in the same solid extension. Furthermore, an argument that is indirectly attacked and indirectly defended by another argument (controversial arguments) cannot be an element of any solid extension. Additionally, applying solid semantics to judgment aggregation yields more positive aggregation outcomes than Dung’s semantics; notably, any quota rule higher than or equal to the strict majority rule preserves solid admissibility for all argumentation frameworks but fails to preserve Dung’s admissibility