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Target controllability for a minimum time problem in a trait-structured chemostat model
No full textIn this paper, we consider a minimum time control problem governed by a trait-structured chemostat model including mutation and one limiting substrate. Our first main result proves the well-posedness of the control-to-state mapping. We subsequently analyze the class of {\it{auxostat-type controls}}, feedback laws designed to regulate substrate concentration, and prove that the corresponding solutions converge to a stationary state of the system. These convergence results are used to show the reachability of a target set corresponding to the selection of a population with a low weighted averaged half-saturation constant. Finally, we show the existence of an optimal control for the minimum time problem associated with reaching the target set. These theoretical findings are completed by numerical simulations
Actes de la 9ème édition du colloque Pédagogie et Formation du Groupe INSA: Adaptation des parcours de formation aux nouveaux enjeux des métiers de l'ingénieur : quelles transformations et quels impacts ?
No full textNational audienceL’évolution du métier d’ingénieur implique une nécessaire réévaluation des parcours de formation, deleurs contenus, des méthodes et outils d’enseignement-apprentissage. À partir de retours d’expérienceet d’expérimentations dans nos établissements, nous pourrons analyser l’impact de ces transformationssur les acquis des étudiants, le développement de leurs compétences et réfléchir aux moyens de favoriserleur engagement dans ces différents dispositifs.La 9e édition du colloque Pédagogie et Formation du Groupe INSA entend questionner ces problématiqueset permettre d’échanger sur les actions en place, le déploiement de projets à l’échelle du groupe (notamment INSA 2025) et les partenariats développés ces deux dernières années
Report on TESCA irradiation of optical sensors and tests of glasses
No full textInternational audienceThe TESCA irradiation campaign, conducted from November 16 to December 17, 2023 (one reactor operating cycle) in the SCK•CEN BR2 research reactor, enabled testing of optical sensors at different development stages, under intense radiation: fast neutron fluence (E > 1MeV) of 1 to 2 x 10¹⁹ neutrons/cm² and gamma dose of about 5 GGy. The temperature ranged between 100°C and 500°C. TESCA irradiation enabled on-line testing of Fabry-Perot extensometers, and miniature, non-contact, hightemperature optical pyrometry sensors. We also report an online measurement of radiation-induced attenuation on a sapphire sample. Because all sensors and measurements aretemperature-sensitive, it was crucial to either maintain stable temperatures or accurately monitor them to assess the impact of radiation on sensor response stability at constant load or on glass parameters. Brief temperature jumps were also applied to test sensors accuracy. An overview of results from monitoring the various sensors and experiments throughout the irradiation cycle are provided. A wellthermally stabilized Fabry–Perot extensometer maintained high stability, with a drift below 1 µm under constant load. It also ensured accurate thermal expansion measurements during temperature jumps. The pyrometric sensors operated effectively under intense irradiation at steady temperature: the collected blackbody emission spectrum was preserved, as expected with constant temperature. The unusable spectral range around the OH peak will be extended to [1250–1430 nm]. In contrast, the RIA setup showed susceptibility to temperature variations and mechanical vibrations, indicating the need for improved mechanical robustness
Un aveugle peut-il refuser de voir ? Optique, critique sociale et cécité à la fin du règne de Louis XV
No full textInternational audienceIn 1771, an anonymous philosophical tale was published, L'Aveugle qui refuse de voir. The eponymous character and that of the oculist who intends to give him sight are two literary effects of the optical and ophthalmological revival of the 17th and 18th centuries, and each embodies a voice of the Enlightenment. The blind man, through the prism of his blindness, produces a critique of the hierarchical and unequal society of the Ancien Régime, insofar as it is based on the sense of sight.En 1771 est publié un conte philosophique anonyme, L’Aveugle qui refuse de voir. Le personnage éponyme et celui de l’oculiste qui entend lui donner la vue constituent deux effets littéraires du renouveau optique et ophtalmologique des XVIIe et XVIIIe siècles, et incarnent chacun une voix des Lumières. L’aveugle, au prisme de sa cécité, produit une critique de la société d’Ancien Régime hiérarchisée et inégalitaire, en tant qu’elle est fondée sur le sens de la vue
Adolescents and young adults with predominantly low grade primary central nervous system tumors: patient reported socioeconomic outcomes and health-related quality of life ten years after diagnosis
No full textInternational audienceContext: Adolescents and young adults (AYAs) diagnosed with primary central nervous system tumors (PCNST) often face long-term socio-economic challenges and reduced health-related quality of life (HRQoL).Objective: This study aims to evaluate the long-term socio-economic outcomes and HRQoL of AYAs more than ten years after diagnosis.hods: A national, retrospective study conducted between 2019 and 2022, including AYAs aged 15–25 diagnosed with PCNST in 2009–2010, identified through the French Brain Tumor Database. Socio-economic data and HRQoL were assessed using a structured questionnaire and the Short Form-12 (SF-12) Health Survey. Descriptive statistical analyses were performed.Results: Questionnaires were available for 70 patients. Educational level improved over time, but 11.4% still lacked a diploma. While 90% were employed, 45% earned €1500–€2500 per month, and 36.7% earned less than €1500 per month. Workplace accommodations were rarely implemented despite needs. HRQoL assessments showed high physical functioning scores (mean: 85.61), but low vitality scores (mean: 35.82). The mean Physical Component Summary and the mean Mental Component Summary are lower to the general population aged 18–44 in France, respectively 50.6 (SD: 9.1) and 43.6 (SD:12.25) showing a poor physical and a very poor mental HRQoL for AYAs survivors.Discussion: Despite resilience in education and employment, AYAs surviving PCNST face persistent socio-economic difficulties and poor mental HRQoL. Tailored interventions, including increased awareness of support resources and comprehensive care strategies, are needed to improve their long-term outcomes and facilitate better integration into society
Stratégies de Stabilisation pour les EDP linéarisées par des méthodes d'optimisation
No full textWe adapt an optimization technique, originally developed for quadratic matrix model updating problems, to construct optimal stabilizers for linearized partial differential equations (PDEs). The proposed approach is flexible, allowing the optimization of mass, damping, and stiffness operators either individually or simultaneously. It is also straightforward to implement within standard numerical frameworks. We analyze the numerical and practical properties of the method, highlighting its robustness even with loworder discretizations and its capacity to produce interpretable stabilization operators. The effectiveness and versatility of the approach are demonstrated through numerical experiments on several representative linearized PDEs, including the Klein-Gordon, Boussinesq, Benjamin-Bona-Mahony, and Korteweg-de Vries equations. Our results indicate that the method provides a unified, efficient, and modular tool for PDE stabilization.Nous adaptons une technique d'optimisation, initialement développée pour les problèmes de mise à jour de modèles matriciels quadratiques, afin de construire des stabilisateurs optimaux pour les équations aux dérivées partielles (EDP) linéarisées. L'approche proposée est flexible, elle permet l'optimisation des opérateurs de masse, d'amortissement et de rigidité individuellement ou simultanément. Elle est également facile à implémenter dans les environnements numériques standards. Nous analysons les propriétés numériques et pratiques de la méthode, en soulignant sa robustesse même avec des discrétisations d'ordre faible et sa capacité à produire des opérateurs de stabilisation interprétables. L'efficacité et la polyvalence de l'approche sont démontrées par des expériences numériques sur plusieurs EDP linéarisées représentatives, notamment les équations de Klein-Gordon, de Boussinesq, de Benjamin-Bona-Mahony et de Korteweg-de Vries. Nos résultats indiquent que la méthode constitue un outil unifié, efficace et modulaire pour la stabilisation des EDP
Reconstruction dentaire 3D haute fidélité par fusion de scans intra-oraux et de données CBCT via des représentations implicites profondes
No full textInternational audienceHigh-fidelity 3D tooth models are essential for digital dentistry, but must capture both the detailed crown and the complete root. Clinical imaging modalities are limited: Cone-Beam Computed Tomography (CBCT) captures the root but has a noisy, low-resolution crown, while Intraoral Scanners (IOS) provide a high-fidelity crown but no root information. A naive fusion of these sources results in unnatural seams and artifacts. We propose a novel, fully-automated pipeline that fuses CBCT and IOS data using a deep implicit representation. Our method first segments and robustly registers the tooth instances, then creates a hybrid proxy mesh combining the IOS crown and the CBCT root. The core of our approach is to use this noisy proxy to guide a class-specific DeepSDF network. This optimization process projects the input onto a learned manifold of ideal tooth shapes, generating a seamless, watertight, and anatomically coherent model. Qualitative and quantitative evaluations show our method uniquely preserves both the high-fidelity crown from IOS and the patient-specific root morphology from CBCT, overcoming the limitations of each modality and naive stitching
Lower‐Limb Strength in Alpine Skiing: Are Maximal, Explosive or Endurance Capacities More Important for Performance?
No full textInternational audienceABSTRACT Maximal force production capacities are essential for skiing performance. Despite the evidence of dynamic demands and fatigue during racing, the relative importance of maximal, explosive, and endurance strength capacities remains unclear. The aim of this study was to investigate the specific association between lower‐limb isometric maximal, rate of force development, and critical force to event‐specific skiing performance. Fifty‐nine skiers were recruited from national (NAT, n = 24) and regional (REG, n = 35) levels. Skiers had their isometric maximal force ( F max), maximal rate of force development (RFDmax), and critical force (CF) assessed on a leg press ergometer. NAT skiing performance in each skiing event (Slalom, Giant‐Slalom, Super‐G, Downhill) was defined as FIS points. For REG skiers, performance was represented in their total time to complete a controlled giant‐slalom race. Force production capacities were compared between NAT and REG using independent t‐tests, with the contribution of each force production capacity to performance (event‐specific FIS points for NAT and experimental race time for REG) assessed via stepwise linear regression models. The alpha value was set at 0.05. NAT presented higher F max (Hedges' g = 1.21, p < 0.001), RFDmax ( g = 1.01, p < 0.001), and CF ( g = 1.88, p < 0.001) than REG. For NAT, performance in Slalom was associated with RFDmax ( R 2 = 0.213) while CF was the sole predictor for Giant‐Slalom ( R 2 = 0.256), Super‐G ( R 2 = 0.209), and Downhill ( R 2 = 0.488). For REG, variance in race time was substantially explained by CF (model R 2 = 0.683). This study provides evidence of an event‐specific relationship between performance and force production capacities and notably the importance of isometric critical force
Una cultura geopolitica lagunare : i saperi geografici, militari e politici dell'Accademia Veneziana
No full textInternational audienceLagoon geopolitical culture: Geographical, military and political knowledge at the c. - In 1558, the newly founded Accademia Veneziana, established and directed by patrician Federico Badoer upon his return from his embassy to Charles V and Philip II, conceived a monumental encyclopaedic programme of printed publications in all branches of knowledge: the Somma delle opere che in tutte le scienze et arti più nobili et in varie lingue ha da mandare in luce l'Academia Venetiana. Among all these ``works in all the most noble sciences and arts'', those dealing with geographical and political topics occupy a unique position, quite new for the time. In this setting, which was eminently Venetian but oriented towards Europe and the world, took shape for the first time the project of a ``reason of state'', conceived as a (geo)political science, i.e. inseparably geographical, military and political.https://documentigeografici.it/index.php/docugeo/article/view/73