HAL-Ecole des Ponts ParisTech
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Lifecycle Wages and Human Capital Investments: Selection and Missing Data
No full textInternational audienceWe derive wage equations with individual specific coefficients from a structural model of human capital investment over the life cycle. This model allows for interruptions in labour market participation and deals with missing data and attrition problems. We propose a new framework that deals with missingness at random and is based on factor decompositions that allow for flexible control of selection. Our approach leads to an interactive effect wage specification, which we estimate using long administrative panel data on male wages in the private sector in France. A structural function approach shows that interruptions negatively affect average wages. Interestingly, they also negatively affect the inter-decile range of wages after twenty years. This is only partly due to the fact that interruptions are endogenous
Évaluer les modèles d’atmosphère en écoutant la houle océanique
No full textBasses fréquences et infrasons : émission, propagation, instrumentation et perception; GABE - Acoustique du Bâtiment et de l'Environnement: GPS - Perception Sonore: GAHA - Aéro et Hydro-AcoustiqueNational audienceLa houle océanique est une source globale et continue d’ondes acoustiques basse fréquence appelées microbaroms, avec un pic d’émission à 0.2 Hz. Les stations infrason du système de surveillance international en détectent les signaux au gré de guides, présents dans la moyenne atmosphère (MA, stratosphère-mésosphère) ou la haute atmosphère (HA, mésosphère-thermosphère), qui en assurent la propagation sur plusieurs centaines à plusieurs milliers de kilomètres. Les modèles météorologiques utilisés en opérationnel pour la simulation de propagation infrason souffrent de biais à ces hautes altitudes du fait de l’absence de mesures (notamment de vent) pour les systèmes d’assimilation de données. Nous expliquons ici comment il est possible d’évaluer la performance de ces modèles dans la MA et la HA en utilisant un modèle global opérationnel de source acoustique océanique en entrée d’une chaîne de simulation des détections de microbaroms en station. Ces simulations sont comparées aux observations au travers d’une métrique pour apporter un diagnostic sur la qualité de simulation du milieu de propagation. Cette chaîne de traitement doit permettre de démontrer l’intérêt de l’assimilation des microbaroms dans les modèles d’atmosphère, et ce afin de pallier le manque de données météorologiques conventionnelles à ces altitudes. En particulier, un objectif est d’apporter des spécifications atmosphériques plus réalistes dans la MA et la HA pour la simulation de propagation, dans le cadre de la surveillance par infrason
Exact output tracking for the one-dimensional heat equation and applications to the interpolation problem in Gevrey classes of order 2
No full textThis paper provides a complete characterization of the Dirichlet boundary outputs that can be exactly tracked in the one-dimensional heat equation with Neumann boundary control. The problem consists in describing the set of boundary traces generated by square-integrable controls over a finite or infinite time horizon. We show that these outputs form a precise functional space related to Gevrey regularity of order 2. In the infinite-time case, the trackable outputs are precisely those functions whose successive derivatives satisfy a weighted summability condition, which corresponds to specific Gevrey classes. For finite-time horizons, an additional compatibility condition involving the reachable space of the system provides a full characterization. The analysis relies on Fourier-Laplace transform, properties of Hardy spaces, the flatness method, and a new Planchereltype theorem for Hilbert spaces of Gevrey functions. Beyond control theory, our results yield an optimal solution to the classical interpolation problem in Gevrey-2 classes, which improves results of Mitjagin on the optimal loss factor. The techniques developed here also extend to variants of the heat system with different boundary conditions or observation points
Spectral architectural geometry
No full textInternational audienceSpectral geometry is a mathematical field that links geometrical properties to eigenvalues of differential operators on surfaces. Although it is a well-established tool in geometry processing and has been used in many contexts, the structural engineering and architectural geometry communities have not yet adopted this framework for shape modeling. This paper aims to explore spectral methods for applications in architectural geometries. A novel methodology for generating anisotropic Laplacian operators based on regions of interest defined by the user is proposed. The potential of spectral methods in structural design is illustrated through design problems expressed on meshes and graphs
Impact of climate change on high wind and solar optimal mixes and system costs: the case of France
No full textInternational audienceAbstract. The electricity generation sector is undergoing profound transformations via the introduction of wind and solar energies. It is impacted by changing climate conditions, both on the demand and the supply side. The impact of a change in wind and solar resource coupled to the change in demand has however not been studied in regard of its effect on optimal investment decisions. We tackle this issue through the use of regional climate projections coupled to a minimalistic electricity system modeling tool. We find that for the case of France, increasing levels of climate change tend to decrease the optimal penetration of wind energy, while the optimal level of installed solar energy remains constant. We propose that this is explained by the interplay of an average effect coupled to a demand to generation correlation. To the contrary of previous literature, we find that the sole impact of climate change has no adverse consequences on system total costs, with adaptation measures being less attractive economically than their passive counterparts. This highlights the importance of specifying the working hypotheses and phenomena taken into account when issuing policymaking advice, and calls for further research exploring how combining all processes related to climate change impact all relevant elements of the electricity generation sector. We also encourage continued research at the climate and energy interface, to increase the precision and interpretability of similar studies
Development of a frost heave experimental setup using MRI
No full textInternational audienceDevelopment of a frost heave experimental setup using MR
Synchrotron 4D X‐Ray Computed Tomography of a Porous Limestone: Influence of Porosity on Deformation Mechanisms at Multiple Scales
No full textInternational audienceThis study investigates the relationship between deformation mechanisms and heterogeneity of porosity of a porous carbonate rock across several scales. The Saint Maximin limestone (SML), characterized by centimeter‐scale alternations of dense and porous zones, serves as a model rock to examine the evolution of deformation modes. Cylindrical samples of 8 mm in diameter, extracted from both the dense and porous zones of the SML, were tested in axisymmetric triaxial conditions with in situ synchrotron imaging. High‐resolution 3D strain fields and porosity maps were derived from synchrotron images to assess local‐scale correlations. The results demonstrate that initial porosity exerts a primary control on strain patterns, spanning from the microscale to the centimeter scale. Under brittle conditions, deformation localizes into bands, predominantly accommodated within the more porous regions, while the denser zones remain largely unaffected. At intermediate confining pressures, heterogeneity induces a transitional behavior where diffuse and localized deformation coexist. In ductile conditions, multiple small compactant bands progressively saturate the sample, leading to porosity homogenization
Direct estimation of earthquake source properties from a single CCTV camera
No full textInternational audienceWe present a direct measurement of the slip-rate function from a natural coseismic rupture, recorded on 28 March 2025, during the moment magnitude ( M w ) 7.7 Mandalay earthquake (Myanmar). This measurement was made using video footage of the surface rupture captured by a closed-circuit television (CCTV) security camera located only meters away from the fault trace. Using direct image analysis, we measured the relative slip at each time step and deduced the slip rate. Our results show a local slip duration of 1.4 seconds and a cumulative slip of ~3 meters, during which surface slip velocity peaked at ~3.5 meters per second with passage of the rupture front. These findings demonstrate the pulse-like nature of the seismic rupture at the location of the recording. Using slip-pulse elastodynamic rupture models, we obtained the complete mechanical properties of this pulse, including the energy release rate
Analyse sociologique de Suivi Conso - Expérimentation d’un service de mesure et d’accompagnement post-rénovation globale en maison individuelle
No full textThis report presents the sociological analysis of the "Suivi Conso" (Consumption Monitoring) experiment by Dorémi, a remote measurement and support service designed for households after a comprehensive energy renovation in detached houses. The experiment had a dual primary objective: to verify the achievement of the post-renovation energy performance target (50 kWh/m²/year) and to promote the proper adoption of new equipment and practices (heating, ventilation, electricity, water). The study, conducted through qualitative interviews with 15 voluntary participants, it highlights a great heterogeneity in participants' profiles and expectations, summarized into five types, ranging from the highly engaged "Learning Guinea Pig" to more "Scientific Geek" or "Passive Client" profiles. The system, which combines consumption readings, personalized reports, and webinars, is deemed relevant, but its appropriation remains uneven and conditioned by households' time availability and level of technical capital. The experiment generated significant learning about the origin of consumption and led to changes in domestic practices, particularly concerning heating control and water consumption. However, the effectiveness of the support is limited by the existence of pre-existing sobriety practices in some households. Finally, participants expressed a strong need to integrate into this service a support function for resolving post-renovation defects, which the "Suivi Conso" system could not provide. The report concludes on the relevance of such a service and raises the question of integrating its functionalities into Dorémi's commercial offer.Ce rapport présente l'analyse sociologique de l'expérimentation "Suivi Conso" de Dorémi, un service de mesure et d'accompagnement à distance conçu pour les ménages après une rénovation énergétique globale en maison individuelle. L'objectif principal de l'expérimentation était double : vérifier l'atteinte de l'objectif de performance énergétique post-travaux (50 kWh/m²/an) et favoriser la bonne appropriation des nouveaux équipements et usages (chauffage, ventilation, électricité, eau). L'étude, menée via des entretiens qualitatifs auprès de 15 participants volontaires met en évidence une grande hétérogénéité des profils et des attentes des participants, synthétisée en cinq types, allant du "Cobaye apprenant" très engagé à des profils plus "Scientifique geek" ou "Client passif". Le dispositif, qui combine relevés de consommation, bilans personnalisés et webinaires, est jugé pertinent, mais son appropriation reste inégale et conditionnée par la disponibilité temporelle et le niveau de capital technique des ménages. L'expérimentation a suscité des apprentissages notables sur l'origine des consommations et a entraîné des changements de pratiques domestiques, en particulier concernant le pilotage du chauffage et la consommation d'eau. Cependant, l'efficacité de l'accompagnement est limitée par l'existence de pratiques de sobriété préexistantes chez certains ménages. Enfin, les participants expriment un besoin fort d'intégrer à ce service une fonction de support et de résolution des malfaçons post-rénovation, que le dispositif "Suivi Conso" n'a pas pu assurer. Le rapport conclut à la pertinence d'un tel service et pose la question de l'intégration de ses fonctionnalités dans l'offre commerciale de Dorém
Modelling bioretention systems: does physical-based mean robust?
No full textInternational audienceThis study aims to test the robustness of a physical based bioretention cell model, given the inaccuracies inherent to our knowledge of the systems’ hydrodynamic. Field monitoring data on a pilot bioretention cell is compared to HYDRUS 1D modelling results for a range of possible soil properties and bottom condition scenarios. The uncertainties in the hydrodynamic properties of the filtration and transition medias as well as the bottom boundary conditions (BCs) are found to significantly affect modelling results for water content dynamics in the filtration media but have limited impact on the long-term water balance of the system