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BIM and GIS integration: planning a digital approach to archaeological site management
No full textInternational audienceThe Pompeii Archaeological Park is an exceptional example of archaeology wherearchitectural features have been almost totally preserved, in the context of an archaeologi-cal excavation. Because of this unique site, a digital management tool constructed uponthe planned conservation needs, requires both the features of a BIM (Building InformationModelling) and a GIS (Geographic Information System). This article presents the first stepstaken towards the design of such system, where the latest research in the integration of thetwo technological domains takes into consideration the requirements from the archeologiststhat will use the system. In particular, semantic mappings between entity classes are explained:the data schemas compared are the open format standards for BIM and GIS, namely IFC andCityGML, against a dedicated taxonomy created specifically for this research on the featuresof Vesuvian architecture
Machine learning for experiments and theory in nonlinear fiber optics
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Une approche épistémologique et critique des lois d’échelle urbaines
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Ultrafast laser-induced extrusion of mono-crystalline nano-pillars from sapphire
No full textInternational audienceA single ultrafast laser pulse, shaped as a radially polarized first-order Bessel beam, induces the formation of high aspect ratio nano-pillars emerging from the bulk of sapphire in a laser-induced extrusion process. Three distinct regimes could be observed depending on laser fluence, ranging from straight nano-pillars to nano-structures shaped by capillary instability. Here, we report transmission electron microscopy (TEM) and transmission Kikuchi diffraction (TKD) structural analysis to reveal the underlying formation mechanisms of the nano-structures for all three regimes. We demonstrate, using crystalline orientation analysis, that they range from the translation of a crystalline rod to the resolidification of a hydrodynamic jet of molten sapphire. Remarkably, all nano-pillars are monocrystalline sapphire. The TEM structural analysis of the materials below the surface also provides new insights into the complex phenomena following the laser-matter interaction and the processes underlying the formation of these structures
Mitigating bias in long‐term terrestrial ecoacoustic studies
No full textInternational audienceLong‐term biodiversity monitoring is needed to track progress towards ambitious global targets to reduce species loss and restore ecosystems. The recent development of cheap and robust acoustic recording devices offers a cost‐effective means of gathering standardised long‐term datasets. Accounting for sources of bias in ecological monitoring and research is a fundamental part of the study design process. To highlight this issue in the context of long‐term terrestrial ecoacoustic monitoring, here we collate and discuss sources of bias arising from (i) hardware devices, (ii) firmware, software and analysis tools and (iii) the deployment environment. One important source of bias is unavoidable changes in recording hardware—to demonstrate how this potentially introduces bias, we present two case studies comparing the output from simultaneous recordings from different recorders. To mitigate biases, we recommend effective documentation of environmental and hardware‐related variables, as well as a long‐term data storage strategy that facilitates reanalysis. Additionally, the use of regular calibration tests to measure variation in the acoustic detection space will facilitate analytical approaches or post‐hoc AI solutions that remove unwanted biases. Synthesis and applications : The sources of bias and suggested mitigations described here will be of relevance to hardware manufacturers, ecological researchers and conservation practitioners. Researchers and conservation practitioners must be fully aware of relevant biases when designing long‐term ecoacoustic studies and should incorporate appropriate mitigations into their study design
Investigating continuous energetic exchange in pole vault to explore technical approaches
No full textInternational audiencePole vaulting offers a rich ground for biomechanical analysis. To achieve peak performance, athletes must manage the creation and transformation of different energy forms. Classical motion capture enable the evaluation of kinetic (Ekin) and potential (Epot) energies based on the center of mass velocity and elevation. The introduction of flexible poles, capable of storing and returning elastic energy, has been a major factor in performance gains and world record progression. Several studies have proposed using net energy gain (Egain) the difference between an athlete’s final and initial mechanical energy as a proxy for muscular work during the jump phase [1]. However, while kinematic analyses offer valuable insights, they remain too global to precisely assess individual movement phases or evaluate the impact of subtle technical or material changes. To obtain more detailed insights, the elastic energy stored in the pole (Epole) must be quantified and integrated into the energy model. This would also allow for quantifying potential energy dissipation between the bending and unbending phases. Various solutions have been proposed to estimate Epole, from simulations to in-practice force measurements. The current gold standard developed by Arampatzis et al. [2], use an instrumented pole plant box with 3D force measurements. However, this setup is costly and mainly limited to training environments, where athletes use softer poles and exhibit lower take-off speeds. To overcome these limitations, we aimed to characterize a wide range of poles differing in brand, length, flex index, and grip position to simulate the relationship between pole chord shortening and Epole. Characterization was performed using a custom-designed bending machine equipped with a brushless motor, controlled by proprietary software. The device gradually pulled the upper end of the pole toward the lower end while a dynamometer (K-Pullv3, KINVENT, Montpellier, France) continuously recorded the applied force. Multiple tests with varying grip lengths allowed us to establish the relationship between grip position, chord reduction, and Epole for each pole. Thanks to partnerships with manufacturers such as ESSX, UCS-Spirit or Nordic, a large database of poles has been tested, enabling a comprehensive energetic balance model. By incorporating pole characterization into a global energy model, we can now compute a continuous energy profile summing Ekin, Epot, and Epole to assess how athletes manage energy transfer and input throughout the vault. This approach enables detailed analysis of how technical choices or minor adjustments in style [3] and pole characteristics affect energy dynamics across different vault phases (e.g., swing, maximal bend, push-off). This could pave the way for enhanced feedback and performance optimization in both training and competition.1. Schade et al. (2000)2. Arampatzis et al. (2004)3. Cassirame et al. (2024
Tracking Molecular Predictors of Relapse in Psoriasis upon Cessation of Biologics: Identification of Highly Relevant Markers
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Microscopie OPTIR pour la caractérisation des microorganismes d'intérêt alimentaire.
No full textInternational audience"La spectroscopie OPTIR (Optical PhotoThermal InfraRed spectroscopy) est une technique de spectroscopie vibrationnelle utilisant un laser à cascade quantique (QCL) moyen-IR accordable qui induit un effet photothermique à la surface de l’échantillon, lorsque la longueur d'onde IR correspond à l’énergie d’un mode de vibration. Cet effet photothermique est mesuré à l'aide d'un laser de sonde, de longueur d’onde dans le visible, focalisé à la surface de l'échantillon [1]. Il s’agit d’une technologie qui permet des mesures de spectroscopie IR ainsi que la réalisation d'images chimiques d'absorption infrarouge, avec une résolution spatiale submicronique identique à celle de l'imagerie photonique et indépendante de la longueur d'onde d’absorption. L'OPTIR offre ainsi une mesure d'absorption IR de qualité, sans contact avec la surface. Adossé à l’UMR PAM, le site imagerie spectroscopique de la plateforme Dimacell met à disposition de la communauté scientifique un microscope basé sur cette technologie avec un équipement permettant également de faire une analyse Raman en simultané et en développe les applications dans le domaine de la microbiologie. L’objectif de cette présentation est de présenter en détails la mise en œuvre de cette technique d'imagerie spectroscopique émergente et de ses potentialités, ainsi que son application pour la caractérisation et l’identification de microorganismes (bactéries, levures, spores).
