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Dissent in Monetary Policy Decisions: Effects, Channels and Implications
No full textInternational audienceWe investigate whether dissent in monetary policy committees affects asset prices. We exploit a feature of the ECB communication for identification: the revelation of dissent during press conferences is separated from policy decision announcements. Following a narrative approach, we compute a novel granular index of ECB dissent for each instrument and identify the dissent direction. Using tick data, we isolate asset price changes exactly when dissent is revealed. Dissent has a strong negative effect on stock prices, that operates specifically around status quo decisions. Dissent is a key driver of stock prices on these days, explaining one-third of their variation
Explorer les imaginaires du monde par la danse : enjeux pédagogiques d’une recherche appliquée
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Conception du séminaire hybride "Patrimoine vivant en ethnoscénologie # Volet 2"[podcasts en ligne + exposition photographique itinérante] Avec : Federica Fratagnoli, Gilberto Icle, François Laplantine, Philippe Liotard, Sylviane Pagès, Kitsou Dubois et Gabriele Sofia.
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A Hybrid Modelling Approach for Hierarchical Control of Structured CPSs
No full textInternational audienceCyber-physical systems (CPSs) include engineered interacting networks of physical and computational components. As they are widely used in many application domains, guaranteeing their correct and proper behaviour is an essential and a challenging issue. This paper aims to contribute to a flexible design and development of structured CPSs, composed of similar elements, and capable of (self-)adaptation to satisfy evolving internal and external constraints, e.g. using control theory. To this end, we make use of their structure and of their behavioural characteristics for modelling by hierarchical motifs both systems' elements and controllers. The motivations and contributions are illustrated on a smart building example
Recension de A Convex Mirror (Oxford University Press, 2024)
No full textNotice bibliographique analytique bilingue (français/anglais)Recension de : Marco Segala, A Convex Mirror, Oxford University Press, 2024. xxx-351 p
Distributed Brillouin measurement in graded index multimode optical fiber
No full textInternational audienceWe present distributed Brillouin measurements realized in a commercially available graded-index few mode optical fiber. The measurements were performed using a Brillouin Optical Time Domain Reflectometer instrumentcoupled with an industrial multiplexer designed for the multimode fiber, enabling the characterization of 15Hermite-Gaussian modes of the multimode fiber. The low intermodal crosstalk observed allowed for reliablemeasurements even in the absence of the multiplexer. Preliminary results of temperature Brillouin frequencycoefficient are also presente
EEG–Metabolic Coupling and Time Limit at VO2max During Constant-Load Exercise
No full textInternational audienceBackground: Exercise duration at maximum oxygen uptake (V˙O2max) appears to be influenced not only by metabolic factors but also by the interplay between brain dynamics and ventilatory regulation. This study examined how cortical activity, assessed via electroencephalography (EEG), relates to performance and acute fatigue regulation during a constant-load cycling test. We hypothesized that oscillatory activity in the theta, alpha, and beta bands would be associated with ventilatory coordination and endurance capacity. Methods: Thirty trained participants performed a cycling test to exhaustion at 90% maximal aerobic power. EEG and gas exchange were continuously recorded; ratings of perceived exertion were assessed immediately after exhaustion. Results: Beta power was negatively correlated with time spent at V˙O2max (r = −0.542, p = 0.002). Theta and Alpha power alone showed no direct associations with endurance, but EEG–metabolic ratios revealed significant correlations. Specifically, the time to reach V˙O2max correlated with Alpha/V˙O2 (p < 0.001), Alpha/V˙CO2 (p < 0.001), and Beta/V˙CO2 (p = 0.002). The time spent at V˙O2max correlated with Theta/V˙O2 (p = 0.002) and Theta/V˙CO2 (p < 0.001). The time-to-exhaustion was correlated with Theta/V˙CO2 (p < 0.001) and Alpha/V˙CO2 (p < 0.001). Conclusions: These findings indicate that cortical oscillations were associated with different aspects of acute fatigue regulation. Beta activity was associated with fatigue-related neural strain, whereas Theta and Alpha bands, when normalized to metabolic load, were consistent with a role in ventilatory coordination and motor control. EEG–metabolic ratios may provide exploratory indicators of brain–metabolism interplay during high-intensity exercise and could help guide future brain-body interactions in endurance performance
Detection of Low-Velocity Impact Damage in Woven-Fabric Reinforced Thermoplastic Composite Laminates by Deep-Learning Classification Trained on Terahertz-Imaging Data
No full textNational audienceTerahertz (THz) imaging is gaining attention as a nondestructive testing technique for assessing damage due to its high axial resolution and nonionizing nature, presenting a promising alternative to conventional methods such as ultrasound and X-ray imaging. Its practical implementation, however, remains limited by the reliance on expert interpretation and the frequent need for validation using supplementary techniques such as X-ray microcomputed tomography (µCT), particularly for complex damage modes. This study focuses on woven-fabric-reinforced thermoplastic composites subjected to low-velocity impact, which typically causes barely visible impact damage (BVID). The damage is subtle yet critical, potentially leading to failure under subsequent loading. The multilayered and spatially distributed characteristics of BVID make it especially challenging to identify. To overcome these challenges, this work integrates deep learning with pulsed THz time-of-flight tomography (TOFT) imaging to enable automated damage detection in composite laminates. In contrast to existing research that mainly targets delamination using A- or C-scan data, this study emphasizes the detection of low-velocity impact damage by leveraging THz B-scans, which offer nondestructive depth-resolved cross-sectional imaging. The training dataset is labeled by correlating THz TOFT scans with X-ray CT images used as ground truth. A transfer learning approach, based on convolutional neural network (CNN) architectures, is employed for binary classification to distinguish damaged from undamaged regions. The resulting classifier achieves over 95 % accuracy, demonstrating the viability of this method for industrial applications such as quality assurance and in-service inspection of composite structures
Contrôle non linéaire d’un convertisseur boost flottant entrelacé à 6 phases avec inductances couplées pour un véhicule lourd à hydrogène
No full textNational audienceL’optimisation de l’intégration des piles à combustible PEM (Proton Exchange Membrane) dans les systèmes de transport lourd nécessite des topologies innovantes de convertisseurs et des commandes avancées. Une architecture de convertisseur boost flottant entrelacé à six phases (6-FIBC), intégrant des inductances couplées, est ici proposée pour améliorer l’efficacité énergétique, la régulation de tension et réduire lesondulations de courant. Cette topologie se révèle particulièrement adaptée aux applications haute puissance des systèmes électriques hybridés. Par ailleurs, une commande non linéaire basée sur la platitude est ici développée, permettant une régulation précise des états du système et une adaptation dynamique aux variations de charge. Les résultats de simulation confirment les performances du système, mettant en évidence une régulation de tension optimisée, un partage équilibré des courants et une efficacité accrue