Portail des publications scientifiques IMT Mines Alès
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Nuisances odorantes industrielles : prévision et représentation spatiale des niveaux de gêne olfactive et d’impact socio-économique sur un territoire
No full textToday, industrial odours are less and less accepted by local residents who fear an impact on their health, their quality of life or the value of their property. To avoid conflict, research was initiated around ten years ago to anticipate the odour nuisance caused by future industrial sites.The aim of this work is to propose a new model for predicting and representing odour nuisance on maps, to help decision-makers proactively manage odour problems and their potential consequences on the functioning in their territory. The research in this thesis follows the work initiated by Popa (2013). One possibility of improvement suggested in this work was to enhance the transferability of the model to other territories.To achieve this, the data set required was simplified. An innovative method was proposed for assessing and predicting the annoyance potential of odours emitted by a future industrial site, and forecasting its impact on a territory. The representation of the results has been adapted to the odour problem and to the users of the tool. Finally, our method can be used to assess and map the odour impact of an existing or future industry from the point of view of odour characteristics and three issues: local residents, economic activities and public infrastructures.The method was validated around an industrial site by comparing its predictions with data from an odour observatory in place around the study site. Even if this work still opens the door to several research perspectives to refine its operational use, the relevance of the results obtained at this stage allows us to consider that it already constitutes a useful decision-making tool for a balanced distribution of activities and people, within the framework of a sustainable development of the territory, place of life, but also of activity.Les odeurs industrielles sont aujourd’hui de plus en plus rejetées par les riverains qui craignent un impact sur leur santé, leur qualité de vie ou sur la valeur de leur bien. Pour éviter que des situations conflictuelles ne surviennent, des recherches ont été initiées il y a une dizaine d’années pour anticiper la gêne olfactive occasionnée par de futurs sites industriels.L’objectif de ce travail est de proposer un nouveau modèle de prévision et de représentation cartographique de la gêne olfactive pour aider les décideurs à gérer de manière proactive les problèmes d’odeurs et leurs conséquences potentielles sur le fonctionnement de leur territoire. Les travaux de recherche présentés dans cette thèse de doctorat font suite à ceux initiés par Popa (2013). Parmi les nombreuses pistes d’amélioration évoquées à l’issue de ce travail, l’amélioration de la transférabilité du modèle à d’autres territoires constituait un point important.Pour y parvenir, le jeu de données nécessaire a été simplifié. Une méthode innovante a été proposée pour évaluer et prévoir le potentiel de nuisance des odeurs émises par un futur site industriel et prévoir ses impacts sur un territoire. La représentation des résultats a été adaptée aux problèmes d’odeur ainsi qu’aux utilisateurs de l’outil. Finalement, notre méthode permet d’évaluer et de cartographier l’impact odorant d’une industrie existante ou future sous le prisme des caractéristiques de l’odeur ainsi que de trois enjeux : celui des riverains, des activités économiques et des infrastructures publiques.La méthode a été validée autour d’un site industriel en confrontant ses prévisions avec les données issues d’un observatoire des odeurs en place autour du site d’étude. Même si ce travail ouvre encore la porte à plusieurs perspectives de recherche pour affiner son utilisation opérationnelle, la pertinence des résultats obtenus à ce stade permet de considérer qu’il constitue d’ores et déjà un outil d’aide à la décision utile pour une répartition équilibrée des activités et des hommes, dans le cadre d’un aménagement durable du territoire, lieu de vie, mais aussi d’activité
Non-destructive measurement of orthotropic elastic properties of wood samples by their modal impulse response
No full textInternational audienceWood represents a major class of versatile materials in mechanics, comparable to metals onvarious criteria such as annual world production tonnage. The density of wood is 3 to 15 timeslower than that of metals, due to its cellular structure, whose walls are essentially made up oflayers of long-fiber nano-composites. This makes wood one of the most efficient materials formany applications. However, the knowledge of the transverse (ER radial modulus and ETtangential modulus) and shear (GRT, GLT and GLR) elastic properties of this orthotropic,heterogeneous, hygroscopic and variable material are still limited due to a lack of rapid andefficient characterization tools and methods. Currently, the existing technical data in databasesare incomplete for material selection since, generally, only the longitudinal elastic modulus isavailable, whereas the other elastic properties are essential for high-end and high-performanceapplications.The aims of this study are: to rapidly estimate as many elastic parameters as possible from asingle wood sample using the modal analysis of its vibrational impulse response; to investigatethe damping characteristics and relate them to viscous behaviour; to enrich the woods databasewith orthotropic elastic constants; and to analyze the correlations between macroscopicviscoelastic behavior and ultrastructural parameters, including density and microfibril angle (AlFay et al. 2022)
Stochastic approaches for multi-echelon disassembly lot-sizing under random lead times
No full textInternational audienceWith the increasing focus on environmental issues, manufacturers are facing pressure to adopt end-of-life item collection practices and maximize the reuse of components or sub-assemblies to their fullest potential. The decision-making processes for disassembly planning and components inventory management become critical as they directly impact a company's production costs and service level. In this particular context, Reverse Material Requirements Planning (RMRP) is a widely utilized method to determine the optimal lot sizes of endof-life (EoL) products for disassembly, ensuring sufficient component supply. Traditionally, these lot sizes are calculated based on deterministic and dynamic demand assumptions when disassembly lead times are either zero or deterministic. However, in this work, we investigate optimization approaches for RMRP systems that consider disassembly lead time uncertainties, in a disassembly multi-echelon lot-sizing problem. We proposed stochastic programming models based on a Monte Carlo simulation approach whose performance is validated that are validated Their performance is validated on several numerical tests
How does the Use of Sonification of Arm Movement Modulate Gesture Reproduction?
No full textInternational audienceIn sports, efficacy of visual and verbal feedbacks is well known for learning or improving gestures. Auditory feedback to the contrary is poorly understood. However, several authors have demonstrated the efficacy of using sonification systems to provide real-time auditory feedback to athletes in diverse types of sports (O'brien et al., 2019). The sonification gives athletes the opportunity to receive direct information about their motion to correct it instantly. This method is also used in physical rehabilitation, after a loss of mobility due to an injury, or a disease as Parkinson's Disease (PD). In this work, we focus on the use of sonification to assess the proprioception and improve the mobility of healthy subjects and patients with PD. Frameworks and Methodology Videos of movements will be shown to the participants who will have to reproduce the same movements faithfully, with or without the sonification system (used in the video and by the participant himself). The movements we chose are characterized by large amplitudes, speed changes, and stops at precise angles, which will have to be reproduced according to the principle adopted in ARJP tests (Han et al., 2016). Gestures are also inspired by the LSVT-BIG Program (a training program for patients with PD). Our experiment will be performed at the AIHM (Ales Imaging and Human Metrology) platform, using the Qualysis motion capture system. Sets of 4 markers (to avoid occlusions) placed on the shoulder, the elbow, and the wrist will be connected to the sound synthesis software Max. The 3D kinematics data of these joints will be mapped in real time to specifics sound parameters so that the subjects will perceive modulation in sound while moving. As the model will also wear the sonification system in the videos, participants will be able to listen the expected sound they will have to reproduce. And so, they will instantly notice if their movement are too small or too slow. Other markers will be placed in the whole body to assess changes in motion. The effect of sonification will be assessed by comparing kinematics of the model and of the reproduction by participants, with and without sonification. In particular, we will quantify the similarity between angular velocity at the elbow and shoulder between model and reproduction, using the Wasserstein distance (Słowiński et al., 2016). Amplitude of movements will also be quantified. Results will focus on the impact of our sonification approach in terms of speed of movement, reproduction of joint position and range of motion. Discussion will address how sonification could be effective in improving movement and providing a source of motivation for users (Nikmaram et al., 2019). Conclusion and perspectives Sonification has a large potential in different fields like sport, rehabilitation or learning but is not yet sufficiently explored. Future works will involve a larger sample of Parkinson's patients assess our hypothesis with the aim of creating a standardized rehabilitation protocol using sonification to facilitate the physiotherapist's work in PD
A drought-triggered hydrological tipping point in the central Sahel: an attribution study using system dynamics modelling
No full textInternational audienceWest Africa experienced severe drought between the 1970s and 1990s. A shift in the hydrological regime was observed in most of the catchments of the central Sahel (the semi-arid fringe south of the Sahara): from the drought onward, runoff increased significantly despite the rainfall deficit, and continues to increase today. Long-term field observations by the AMMA-CATCH observatory and other research programs in this region suggest that this rainfall-runoff decoupling regime is associated with the crossing of a tipping point. In this study, we investigated whether the drought of the 1970s-1990s could have triggered this shift. We used a simple system dynamics model representing feedbacks between rainfall, herbaceous and woody vegetation and runoff at the catchment scale. These feedbacks allow to represent the local response of vegetation to rainfall, soil water and runoff as an internal, dynamical process. The model forced with observed rainfall since the 1950s proved robust, as it reproduced well the runoff dynamics observed during this period in a selection of catchments in the central Sahel and the southern sub-humid zone closer to the Gulf of Guinea. Using historical CMIP6 precipitation simulations, the probability of a regime shift was found to be twice as high when the model was forced with a rainfall series reproducing drought (fully coupled ocean-atmosphere climate simulations) than with a series without drought (AMIP - atmosphere only). We conclude that drought was a sufficient factor to trigger the observed regime shift, although other processes (not questioned here) may have been simultaneously involved, such as human-induced land cover changes. With a "conventional" hydrological model, the regime shift observed in the central Sahel could only have been reproduced by prescribing both rainfall and the evolution of surface conditions. Our results suggest that, at least in arid and semi-arid regions, the inclusion of rain-vegetation-runoff feedbacks in critical zone models could help improve simulations and better assess the likelihood of triggering hydrological tipping points under future climate and land cover change scenarios
Small-Producer Selection and Order Allocation in the Agri-Food Supply Chain
No full textInternational audienceProducer diversification and order allocation are problems in the operational research field that require decisionmaking skills from the side retailers so that they can choose from who and when to place orders to meet their demand. These tasks are especially challenging in the agricultural field since orders need to be placed months in advance for some products to take into account the time required for planting and farming the produce. This work presents an exploratory model that tackles the challenge of farmer selection and order allocation. We develop a linear program that minimizes the demand cost while considering quantity-dependent pricing and a variety of constraints that agricultural retailers face
Comparison of wrist actimetry variables of paretic upper limb use in post stroke patients for ecological monitoring
No full textInternational audienceAbstract Background To date, many wrist actimetric variables dedicated to measuring the upper limbs (UL) in post-stroke patients have been developed but very few comparisons have been made between them. The objective of this study was to compare different actimetric variables of the ULs between a stroke and healthy population. Methods Accelerometers were worn continuously for a period of 7 days on both wrists of 19 post-stroke hemiparetic patients as well as 11 healthy subjects. Various wrist actimetry variables were calculated, including the Jerk ratio 50 (JR50, cumulative probability that the Jerk Ratio is between 1 and 2), absolute (FuncUse30) and relative (FuncUseRatio30) amounts of functional use of movements of the ULs with angular amplitude greater than 30°, and absolute (UH) and relative (UseHoursRatio) use hours. Results FuncUse30, FuncUseRatio30, UH, UseHoursRatio and JR50 of the paretic UL of stroke patients were significantly lower than in the non-dominant UL of healthy subjects. Comparing the ratio variables in stroke patients, FuncUseRatio30 was significantly lower than UseHoursRatio and JR50, suggesting a more clinically sensitive variable to monitor. In an exploratory analysis, FuncUseRatio tends to decrease with angular range of motion for stroke patients while it remains stable and close to 1 for healthy subjects. UseHoursRatio, FuncUseRatio30 and JR50 show linear correlation with Fugl-Meyer score (FM), with r 2 equal to 0.53, 0.35 and 0.21, respectively. Conclusion This study determined that the FuncUseRatio30 variable provides the most sensitive clinical biomarker of paretic UL use in post-stroke patients, and that FuncUseHours—angular range of motion relationship allows the identification of the UL behaviour of each patient. This ecological information on the level of functional use of the paretic UL can be used to improve follow-up and develop patient-specific therapy
Incremental Transformation of BPSIM-Enriched BPMN Models into DEVS
No full textInternational audienceThis paper introduces a novel methodology for business process simulation, focusing on the incremental transformation of Business Process Modeling and Notation (BPMN) models enriched with Business Process Simulation Interchange Standard (BPSIM) elements into the Discrete Event System Specification (DEVS) formalism. The proposed method enhances the precision and consistency of simulations by systematically converting BPMN components and BPSIM characteristics into DEVS representations, using adaptable rules and templates. A major contribution of this work is the introduction of the Interaction Intermediate Model (I2M), a model that provides a visually lucid representation with significant semantics, effectively encapsulating BPMN and BPSIM simulation aspects. The resulting DEVS model ensures accurate, reliable, and interoperable simulations. We provide a thorough analysis of this methodology, emphasize its advantages, and validate its efficiency through a case study. This method, applicable across various sectors, equips stakeholders with the ability to make informed decisions based on accurate simulation insights, effectively bridging the gap between conceptual modeling and simulation methodologies
Gestion de crise et inondations : du discours à la mutualisation des ressources humaines d’un territoire
No full textThis PhD enrolled in Information and Communication Sciences is financed by the Agglomeration of Alès in France and the Laboratoire des Sciences des Risques of IMT Mines Alès. The territory of Alès is located in the French department of Gard and is particularly exposed to major flooding risks. The thesis aims to improve crisis management and to be integrated in the development of an Intercommunal Safeguard Plan (Emergency Management Plan), which will rule all actions to be undertaken during extreme weather events.The study is based on qualitative approaches and Grounded Theory to analyse crisis situations, focusing on communication, social psychology and management. The analysis includes 90 hours of semi-structured interviews and two complementary analysis phases. The first phase consists of an overall analysis of the responses in order to identify research questions, while the second phase consists of a thematic encoding of the transcripts in order to answer these research questions.The results reveal four categories of expectations expressed by the respondents: preparedness, planning, actions during the crisis and risk culture. On this basis, three objectives are defined for the study: (a) to develop paths of improvement for crisis management in Alès, (b) to determine whether municipalities share operational and representational logics, and (c) to determine the elements that characterize a common logic. This thesis highlights the importance of mutualisation in intermunicipal crisis management and the need for a shared understanding of risk and crisis management among actors.Cette thèse inscrite en Sciences de l’Information et de la Communication est financée par l’Agglomération d’Alès en France et le Laboratoire des Sciences des Risques de l’IMT Mines Alès. Le territoire d’Alès est situé dans le Gard et est particulièrement exposé aux risques majeurs d’inondation. La thèse vise à améliorer la gestion de crise et à être intégrée dans le développement d’un Plan Intercommunal de Sauvegarde (PIS), qui régira toutes les actions à entreprendre lors d’événements météorologiques extrêmes.L’étude est basée sur des approches qualitatives et sur la Grounded Theory pour analyser les situations de crise, en mettant l’accent sur la communication, la psychologie sociale et la gestion. L’analyse comprend 90 heures d’entretiens semistructurés et deux phases d’analyse complémentaires. La première consiste en une analyse globale des réponses afin d’identifier des pistes de recherche, tandis que la seconde consiste en un encodage thématique des transcriptions afin de répondre à ces questions de recherche.Les résultats révèlent quatre catégories d’attentes exprimées par les personnes interrogées : la préparation, la planification, les actions pendant la crise et la culture du risque. Sur cette base, trois objectifs sont définis pour l’étude : (a) développer des pistes d’amélioration pour la gestion de crise à Alès, (b) déterminer si les municipalités partagent des logiques opérationnelles et de représentation, et (c) déterminer les éléments caractéristiques d’une logique commune. Cette thèse met en évidence l’importance de la mutualisation dans la gestion intercommunale des crises et la nécessité d’une compréhension partagée des risques et de la gestion de crise par les acteurs