Portail HAL UHA (Université de Haute-Alsace)
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PhyDeformer: High-Quality Non-Rigid Garment Registration with Physics-Awareness
No full textInternational audienceAccurately registering 3D garment meshes to real-world image data is a fundamental yet challenging task in computer vision and graphics, with applications in virtual try-on systems, digital fashion, performance capture, and virtual content creation. This problem involves recovering detailed, non-rigid garment geometry from partial, noisy, and often ambiguous visual cues extracted from 2D or reconstructed 3D data. A key challenge lies in aligning garment templates with target shapes while preserving realistic fabric behavior and accommodating variations in body shape, garment fit, and pose. We present PhyDeformer, a new deformation method for high-quality garment mesh registration. It operates in two phases: In the first phase, a garment grading is performed to achieve a coarse 3D alignment between the mesh template and the target mesh, accounting for proportional scaling and fit (e.g. length, size). In the second phase, the graded mesh is refined to capture fine-grained geometric details of the 3D target through a localized optimization process, leveraging a Jacobian-based deformation framework. Both quantitative and qualitative evaluations on synthetic and real garment data demonstrate the effectiveness and robustness of our method in achieving accurate and visually plausible registrations
Advanced models and a hybrid method for electric vehicle charging scheduling with diverse charger characteristics
No full textInternational audienceThis paper investigates the Electric Vehicle Charging Scheduling Problem (EVCSP) to maximize satisfied charging demands while optimizing resource utilization. Specifically, it addresses scenarios involving non-identical chargers with constant and variable output power, as well as intro- ducing a novel configuration featuring chargers with discrete variable output levels. Enhanced mathe- matical models are formulated for the constant and variable output power scenarios, extending existing formulations in the literature, while a new model is introduced to capture the discrete-level config- uration, reflecting modern charging behaviors. To address scalability challenges in large instances, a hybrid solution framework is proposed, where the problem is decomposed into two interrelated parts: vehicle-to-charger assignment, handled by the Adaptive Differential Evolution (JADE) algorithm, and energy allocation, optimized through a dedicated mathematical programming model. Computational experiments demonstrate that the proposed mathematical models for constant and variable output power outperform existing approaches in the literature. The model developed for the variable output power scenario consistently yields high-quality solutions across all instance sizes, whereas the models for the constant and discrete-level scenarios are effective primarily for smaller instances. As problem size and complexity increase, the hybrid JADE framework becomes more effective, delivering high-quality solutions and exhibiting strong scalability and practical applicability
« Le SMCB se devait d'être le Maître d'Oeuvre de ces études multidisciplinaires ». Radiological Control and Environnemental Studies of the French Nuclear Tests in the 1960s
No full textInternational audienceWhen the French decided to test their nuclear devices in Polynesia, knowledge of the South Pacific environment was scarce, even though it was a key factor in controlling radioactivity and protecting health. The Service Mixte de Contrôle Biologique, created in 1964, was dedicated to studying the effects of the tests on the environment and in particular on non-human living organisms. The presentation will focus on the process developed by the SMCB to gather information on the local environment and monitor contamination of human bodies through the trophic chain. At the heart of this study, civilian scientists under contract to the Direction des Centres d'Expérimentations Nucléaires (DirCEN) contributed their knowledge of the Pacific environment to enlighten the military, doctors and atomic scientists and help them design a process for assessing the direct and indirect impact of detonations on the environment. How did these scientists interact with those in charge of the nuclear tests? How did their tasks and personal motivations fit into the nuclear framework of the DirCEN? We will focus on two moments in this collaboration to explore the agentivity of these contractors and their influence on the creation of an environmental monitoring system: firstly, the two-year period preceding the tests, when the biologists and the SMCB carried out the first environmental studies and chose the means of monitoring radioactivity in the natural world, and secondly, the aftermath of the first test campaign. A comparison between the initial framework and its actual application shows some divergences and reveals the variety of motivations underlying environmental monitoring. It also shows that despite these differences, scientists took advantage of such an opportunity to advance science with real agency, while the DirCEN took advantage of the precise and technical knowledge of these scientists to strengthen its control over the trophic chain
Color–polarization filter array image demosaicing: linear minimum mean squared error augmented by anisotropic diffusion
No full textInternational audienceLinear minimum mean square error can be used to demosaic images from a colour-polarization filter array sensor. Despite its good performance, the reconstruction produces high-frequency artefacts. An additional refinement step could enable to enhance both the quantitative and visual quality of the demosaiced image. We propose a complete demosaicing framework, by first studying the model selection for LMMSE using cross-validation techniques, and then optimizing the anisotropic diffusion parameters. The results show that the training model converges quickly, and that the refinement step enables to reduce the edge artefacts. We also demonstrate that the proposed demosaicing method performs better compared to a dedicated Colour-Polarization Filter Array demosaicing algorithm in terms of PSNR.</div
Rapid Prototyping of 3D Microstructures: A Simplified Grayscale Lithography Encoding Method Using Blender
No full textInternational audienceThe democratization of fabrication equipment has spurred recent interest in maskless grayscale lithography for both 2D and 3D microfabrication. However, the design of suitable template images remains a challenge. This work presents a simplified method for encoding 3D objects into grayscale image files optimized for grayscale lithography. Leveraging the widely used, open-source 3D modeling software Blender, we developed a robust approach to convert geometric heights into grayscale levels and generate image files through top-view rendering. Our method accurately reproduced the overall shape of simple structures like stairs and ramps compared to the original designs. We extended this approach to complex 3D sinusoidal surfaces, achieving similar results. Given the increasing accessibility and user-friendliness of digital rendering tools, this study offers a promising strategy for rapid prototyping of initial designs with minimal effort
Municipales 2026 : vers des réformes conséquentes et tardives du droit électoral ?
No full textInternational audienc
La Polynésie française à l'heure des essais : un laboratoire des sciences de l'environnement
No full textInternational audienceCette communication interroge la manière dont le développement des sciences de l’environnement est lié à l’implantation et au fonctionnement du CEP que ce soit via l’appui, pour ne pas dire la caution, scientifique qu’elles ont pu lui donner ou à travers l’anticipation d’une transition post-CEP. Partant du constat de l'existence de référentiels variés pour appréhender l'impact environnemental des essais nucléaires, et de celui d'une méconnaissance initiale flagrante du milieu polynésien au moment de l'implantation du CEP, nous mettons en lumières trois dynamiques dominantes dans la construction des savoirs occidentaux sur les environnements du Pacifique sud. Les années 1960 sont ainsi marquées par une science balbutiante, essentiellement focalisée sur la gestion du contentieux et menées par des scientifiques français qui, en travaillant avec la DirCEN, profitent d'une opportunité unique de faire de la recherche dans un milieu méconnu. Dans les années 1970, les sciences de l'environnement s'intègrent plus explicitement dans les projets développementalistes qui accompagnent le CEP, concrétisant un objectif énoncé dès les années 1960 mais qui se fait plus urgent et qui se traduit par l'institutionnalisation de la recherche : plusieurs organismes sont créés ou déployés en Polynésie et contribuer, à différents niveaux, à la mise en valeur du territoire. Les années 1980, enfin, sont l'occasion d'un premier bilan des transformations environnementales de la Polynésie et des impacts directs et indirects des essais, mais aussi de l'affirmation d'un conservationnisme qui trouve ses traces dans la décennie précédente mais qui se déploie plus densément dans les îles et archipels de Polynésie. Conditionnés par la représentation des écosystèmes insulaires pensés comme des échelles propices à la science, cette politique aboutit à la création d'îles-laboratoires et d'îles-sanctuaires, deux vocations loin d'être incompatibles dans l'esprit des scientifiques
