Portail HAL UA (Université d'Angers)
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Automatisation de la tomographie robotisée de pièces de grandes tailles. : contributions à la planification de trajectoires synchronisées de bras robotiques
No full textThe thesis explores the automation of robotic tomography for the analysis of large parts, a key challenge in industrial sectors such as aerospace and energy. The primary objective is to overcome two major obsta cles: the feasibility of trajectories in complex configuration spaces and the scheduling of robotic tasks, while addressing strict synchronization and collision avoidance constraints. The first contribution is based on an innovative method that employs decomposition into [x]-contractible tiles, combining interval analysis and graph theory. This approach efficiently calculates the number of connected components in configuration spaces, offering a significant improvement in computational complexity compared to state of the art techniques. The second contribution introduces the Max-MatRTSP algorithm, specifically designed to coordinate two robots in a tomographic environment. This algorithm simultaneously integrates trajectory planning and task scheduling, accounting for specific industrial con straints. Validated through simulations and ex- periments on real systems, it has demon strated superior performance compared to existing methods.La thèse explore l’automatisation de la tomographie robotisée pour l’analyse de grandes pièces, un défi clé dans les secteurs industriels comme l’aéronautique et l’énergie. L’objectif principal est de surmonter deux obstacles majeurs : la faisabilité des trajectoires dans des espaces de configuration complexes et l’ordonnancement des tâches robotiques, tout en répondant aux contraintes de synchronisation stricte et d’évitement des collisions. La première contribution repose sur une méthode innovante utilisant la décomposition en pavés [x]-contractiles, combinant analyse par intervalles et théorie des graphes. Cette approche permet de calculer efficacement le nombre de composantes connexes dans les espaces de configuration, offrant une amélioration significative de la complexité computationnelle par rapport aux techniques conventionnelles. La seconde contribution introduit l’algorithme MaxMatRTSP, spécialement conçu pour coordonner deux robots dans un environnement tomographique. Cet algorithme intègre simultanément la planification de trajectoires et l’ordonnancement des tâches, en prenant en compte les contraintes industrielles spécifiques. Validé à travers des simulations et des expérimentations sur un système réel, il a démontré des performances supérieures aux méthodes actuelles
Landscape coevolution of human-geomorphic system in northern Kyûshû (Japan) induced by the July 2017 heavy rainfall
No full textInternational audienceOn 5-6 July 2017, during the rainy season, heavy rainfall battered northern Kyûshû (Japan), breaking previous records, with 516mm in 24 hours and a maximum intensity of 129.5 mm/h at the Asakura station in the lowlands. In mountainous areas, the total rainfall was between 600 and 800mm in 24 hours. As a result, hundreds of landslides were triggered, mobilizing large quantities of sediment and driftwood, with a regional estimation of respectively 10 million and 210 000 cubic meters (KRDB, 2017). These floods caused 42 casualties and extensive material damage, as well as multi-meters deposits in several valley bottoms. This is a «Low Frequency / High Magnitude» (LFHM) event with an estimated probability of occurrence of 1/200 (KRDB, 2017).This event produced major landscape changes mainly linked to the triggering of landslides, which constitute a sudden and massive opening of sedimentary sources whose contribution to the sediment cascade is 1) facilitated by the very high general sediment connectivity and 2) goes beyond the 2017 event.To mitigate the vulnerability of populations, Japan has undertaken major countermeasures works to stabilize slopes and develop rivers (check dams, sedimentation basins, recalibration), relying heavily on engineering and concrete. The outcome is profound geomorphological changes, reinforced by human intervention through the development and management of these hydrosystems, which modify 1) the sediment cascade and the connectivity settings from a structural and process-based perspective and 2) the specific socio-ecological system of these rural mountain areas called «Satoyama» (Indrawan et al., 2014). The main example is the change of function of areas, changing from a living space with agricultural production area to a sedimentary storage area. Therefore, these elements illustrate a complex process-response feedback loop in a coupled humain-geomorphic system (Poeppl et al., 2017).In a climate change context, heavy rainfall events are expected to increase, including in East Asia and the Japanese archipelago (MEXT JMA, 2020; MLIT, 2020). Related hazards such rapid-moving landslide is predicted to increase along with the population exposed to landslide risk (Gariano and Guzzetti, 2016).This raises the question of the relaxation time of geomorphological systems between two disturbance phenomena like LFHM events, in a context of sometimes increased sensitivity. The torrential rain of 10 July 2023 is a significant example in our case, as it was the 2nd record for maximum hourly intensity with 72.5 mm/h and third for cumulative rainfall over 24 hours with 290.5mm (behind 2018 with 295.5mm) (JMA, 2024). The newly-built countermeasures were therefore put to the test and proved their effectiveness overall, but the increased sensitivity of these systems combined with the magnitude of the 2023 LFHM event exceeded the countermeasure system's absorption capacity calibrated for a specific return period. As a result, most of the check dams have been filled up massively, leading to flooding and massive sediment deposits in several valley bottoms, which provides some insight into the real extent of human-induced disturbance to the sediment cascade
Association between major cardiovascular events and esketamine: A disproportionality analysis in the WHO pharmacovigilance database
No full textInternational audienc
Les incapacités du corps dans la pensée des canonistes latins d’Occident (XIIe-XIIIe siècles). Jalons méthodologiques pour une histoire juridique des corps déficients au Moyen Âge
No full textInternational audienc
Agglomération(s)
No full textInternational audienceDans un contexte d’esthétisation croissante des modes de vie, de consommation et de conception des espaces habités, le phénomène d’agglomération des activités artistiques, culturelles et créatives constitue l’un des principaux objets d’attention de la littérature scientifique s’intéressant aux dynamiques spatiales et territoriales des sociétés urbaines. L’objectif de ce chapitre est de revenir sur les fondements théoriques de ce phénomène. Il s’agira de présenter : (1) les déterminants de la concentration spatiale d’activités spécialisées et ses enjeux en termes d’innovation ; (2) la manière dont cette concentration géographique interfère avec l’organisation sociale du territoire, par l’intermédiaire notamment de communautés ; enfin (3) le rôle que jouent les attributs territoriaux (structures sociales, morphologie urbaine, etc.) dans ces processus, nous permettant dès lors de considérer l’espace urbain autrement que comme un réceptacle neutre
Toward inclusive innovation: The impact of AI on hybrid entrepreneurial landscapes
No full textInternational audienceThis article investigates the role of artificial intelligence (AI) in transforming entrepreneurialecosystems. It focuses on the interactions between formal and informal sectors in Morocco. AI’stransformative potential is attracting growing attention. However, its integration into hybridentrepreneurial settings remains underexplored. The research uses a qualitative case studymethodology. It examines how AI helps entrepreneurs overcome structural barriers. It also showshow AI enhances operational efficiency. Moreover, it allows access to alternative financingmechanisms. The findings highlight AI’s dual impact. It optimizes entrepreneurial practices. Italso fosters synergies between formal and informal actors. However, challenges remain. Theseinclude digital inequalities, high implementation costs, and socio-cultural constraints. This studyoffers concrete recommendations. It contributes both theoretically and practically. It advocates fora more inclusive and sustainable integration of AI. This is especially important in emergingentrepreneurial environments
Meta-learning of Univariate Estimation-of-Distribution Algorithms for Pseudo-Boolean Problems
No full textInternational audienceWe propose a new framework for univariate Estimation-of-Distribution Algorithms (EDAs) in which neural networks are used at two levels: (i) for generating new solutions from a memory that encodes some information acquired since the beginning of the search, (ii) for updating this memory with the new solutions sampled at each iteration. These neural networks are then learned by neuro-evolution, so as to automatically discover new efficient strategies for solving pseudo-Boolean problems, without having any specific a priori on how to design them. The algorithms discovered demonstrate their competitiveness compared with existing univariate EDAs of the literature. On average, they achieve better scores for the same number of calls to the objective function, when tested on a variety of different distributions
Mise en œuvre du dépistage du cancer du poumon en France (Plénière, communication orale invitée)
No full textInternational audienc
Eco-environmental, and social impacts of producing electricity with various renewable energy sources
No full textInternational audienceThe shift towards renewable energy is crucial for mitigating climate change and reducing dependency on fossil fuels. Exploring the diverse impacts of renewable energy sources is essential to guide future investments and policies. This study comprehensively compares five different renewable energy sources-solar, wind, biomass, hydropower, and pumped storage-used to produce electricity, focusing on their economic, environmental, and social impacts. Economic evaluations are conducted using the Levelized Cost of Energy (LCOE), revealing values of approximately 0.048, 0.030, 0.065, 0.045, and 0.085 €/kWh for the respective sources. Environmental impacts are assessed using the OpenLCA software, which evaluates ten midpoint impact categories that culminate in three endpoint damages: human health, ecosystem health, and natural resources. Accordingly, the Environmental Cost Indicator (ECI) was calculated, with results indicating values of around 0.0104, 0.0045, 0.0019, 0.0004, and 0.0180 €/kWh. Additionally, the social impacts these renewable energy sources are considered, highlighting the broader implications of their adoption. This comprehensive analysis provides a detailed understanding of the trade-offs involved in choosing different renewable energy sources, aiming to support sustainable energy transition strategies
Le chantier « Agroécologie & Marché » conduit par les groupes filières INRAE
No full textLe secteur agroalimentaire fait l’objet d’une segmentation croissante du marché avec la multiplication de démarches dites de qualité, publique ou privée, qui engagent les filières dans la construction de pratiques de production, de transformation ou de distribution différenciées. Nous connaissons peu de choses sur la manière dont ces démarches inscrivent leurs pratiques dans l’agroécologie, et en particulier pour les filières ayant une mention valorisante autre que l’agriculture biologique. De 2022 à 2023, la Direction Scientifique Agriculture INRAE a engagé un chantier exploratoire, avec 11 groupes filières INRAE, pour analyser comment se construisent des démarches de filières différenciées sur le marché et leur engagement en faveur de l’agroécologie.National audienceThe agri-food sector encountered an increasing market segmentation, with the proliferation of public and private quality labels, which commit the supply chains to the building of differentiated production, processing and distribution practices. We know very little about the way in which the value chains move towards agroecology, and in particular for the value chains with quality labels other than organic farming. From 2022 to 2023, INRAE's Scientific Division for Agriculture has launched an exploratory project, with 11 INRAE value-chain groups, to analyze how differentiated supply chains are committing toward agroecology. This project, entitled “Agroecology and Market”, was based on a desk research and interviews with over 60 actors from the interbranches and different streams in agrifood chains. This introductory article presents the initial thinking behind the project, the mission of the value-chain groups and the 28 case studies selected for illustrative purposes, in order to conduct this exploratory analysis within a diversity of production and supply chain contexts.Innovations agronomiques 100 (2025), 1-12 RésuméLe secteur agroalimentaire fait l'objet d'une segmentation croissante du marché avec la multiplication de démarches dites de qualité, publique ou privée, qui engagent les filières dans la construction de pratiques de production, de transformation ou de distribution différenciées. Nous connaissons peu de choses sur la manière dont ces démarches inscrivent leurs pratiques dans l'agroécologie, et en particulier pour les filières ayant une mention valorisante autre que l'agriculture biologique. De 2022 à 2023, la Direction Scientifique Agriculture INRAE a engagé un chantier exploratoire, avec 11 groupes filières INRAE, pour analyser comment se construisent des démarches de filières différenciées sur le marché et leur engagement en faveur de l'agroécologie. Ce chantier dénommé « Agroécologie et Marché » s'est appuyé sur une analyse documentaire et une série d'entretiens auprès de plus de 60 acteurs, représentatifs d'interprofessions et de différents maillons de diverses filières. Cet article introductif présente la réflexion initiale de ce chantier, la mission des groupes filières et les 28 cas d'études retenus à titre illustratif, pour conduire cette analyse exploratoire au regard d'une diversité de contextes de production et de filières.</div