Portail des publications scientifiques IMT Mines Alès
Not a member yet
5198 research outputs found
Sort by
Soft Robotic Bilateral Rehabilitation System for Hand and Wrist Joints
No full textInternational audienceUpper limb functionality is essential to perform activities of daily living. It is critical to investigate neurorehabilitation therapies in order to improve upper limb functionality in post-stroke patients. This paper presents a soft-robotic bilateral system to provide rehabilitation therapy for hand and wrist joints. A sensorized glove that tracks finger and wrist joint movements is worn on the healthy limb, which guides the movement of the paretic limb. The input of sensors from the healthy limb is provided to the soft robotic exoskeleton attached to the paretic limb to mimic the motion. A proportional derivative flow-based control algorithm is used to perform bilateral therapy. To test the feasibility of the developed system, two different applications are performed experimentally: (1) Wrist exercise with a dumbbell, and (2) Object pick-and-place task. The initial tests of the developed system verified its capability to perform bilateral therapy
Accounting for mesoscale geometry and intra-yarn fiber volume fraction distribution on 3D angle-interlock fabric permeability,International Journal of Multiphase Flow
No full textInternational audienceUnderstanding resin flows within 3D interlock fabrics involves addressing a dual-scale flow problem. Indeed, the fluid can flow through inter-yarn channels, characterized by a unit cell mesoscale morphology, but also within yarns considered as homogeneous equivalent porous media. The former is assumed to follow the Stokes’ law while the latter be related to the Darcy’s law, directly linked to the microscopic intra-yarn fiber volume fraction (FVF) field. In this work, a coupled Stokes–Darcy steady-state flow within a 3D woven textile, modeled at mesoscale, is solved through a finite element monolithic approach with a mixed velocity-pressure formulation, stabilized by the Variational MultiScale Method (VMS) and implemented in the Z-set software. The fabric permeability tensor is then computed without any assumptions on its nature and analyzed both through its diagonal components, its eigenvectors and eigenvalues. The main contribution of this study lies in examining the influence of variations of the inter-yarn porous medium morphology, through textile compaction and geometrical reduction to prevent edge flows, and the intra-yarn permeability (from complete field to unique value) on the overall fabric permeability
Requirements for comparative life cycle assessment studies for single-use and reusable packaging and products: recommendation for decision and policy-makers: Letter to the editor
No full textInternational audienceLife cycle assessments (LCAs) are sensitive snapshots of a products’ environmental impact, and their findings depend on how they are framed and modelled. Variations in assumptions, functional unit or system boundaries can completely change results and undermine their applicability and final outcome. In the framework of the circular economy, particularly important assumptions for reusable and single-use packaging include the number of reuses, weight, sanitising method, transport logistics and any other aspect which may influence the use phase. In addition, these variables are not fixed over time and may be affected by future changes in product design, consumers’ habits or the supply chain management. As a consequence, the impact of different packaging options is not immutable and could change. Therefore, while comparing reusable versus single-use packaging, there is an urgent need to clarify and integrate the methodological requirements necessary to guarantee the reliability of studies and allow for impartial comparability of results
Sorption of water and ethanol pure vapours and vapour mixtures by four hardwoods
No full textInternational audienceWater is a universal solvent and swelling agent that is widely used in wood industry in association with organic solvents and salts, whether for the fractionation of biomass and the production of bio-based synthons for the chemical industry, the application of sizing agents and painting for the paper industry or the incorporation of preservatives to enhance wood durability for the timber industry. The relevance of solvents and technical treatments used for wood-based products requires a proper identification of the specific role of each solvent on wood biopolymers to better understand and predict their influence on wood properties. In particular, wood impregnated with aqueous solutions of organic solvents has shown to give rise to greater swelling than that observed in pure water, described as “hyperswelling”. To understand this phenomenon, the first step is to examine the existing interactions between wood microstructure and the different solvents present in these mixtures. This study is an attempt to bring to light the sorption behaviour of four different hardwoods in water–ethanol vapour mixtures containing increasing molar fractions of ethanol from 0 to 100%. Contrasted sorption behaviour in pure solvents was observed according to wood species having different biochemical compositions. This behaviour highlights the different affinities of ethanol and water for the macromolecules present in the wood microstructure. With mixed solvents, peculiar effects were confirmed in sorption behaviour of woods with lower mixed solvent uptake at high partial pressures compared to pure solvents. It is also shown that part of the sorbed ethanol molecules remains chemisorbed in the wood structures at the end of the desorption process
Monitored indentation for the detection of inclusions in elastomer material
No full textInternational audienceThe detection of inclusions in soft material is of great interest, especially in the medical field. Traditionally, a biopsy exam is performed after palpation, when necessary. In the present work, a potentially quantitative method, via monitored indentation, is used to mimic palpation. This method consists in investigating the relaxation and stress‐free relaxation responses to an indentation test performed on a silicone block with an inclusion. The aim of the study is to evaluate how a difference in position, size and adhesion of the inclusion can influence the response of the samples to monitored indentation. A finite element model is constructed to conduct comparative studies. The hyper‐viscoelastic parameters of the silicone have been identified experimentally. Results from the simulations showed that the indicators measured during monitored indentation, especially during the stress‐free relaxation phase, are sensitive to adhesive inclusions, while they provide little information regarding their non‐adhesive counterparts. Depths and sizes for which adhesive inclusions are more likely to be detected have been identified. These results are encouraging but are conducted on polymer material and a rigid inclusion; nevertheless, they suggest that the non‐destructive measure of the stress‐free relaxation response of a tissue may help practicians to quantitatively characterize the nature of a nodule
Bridging digital and physical realms: cross-evaluating intrusion detection models in cyber-physical systems
No full textInternational audienceThe application of digital models in industries is recently being used as a means to enhance the operational efficiency of cyber-physical systems (CPSs). However, this comes with challenges bordering mostly around the detection of cyber-attacks using replication as a means. This study considers a synthetic digital object dataset and its equivalent physical object for intrusion detection using principal component analysis (PCA) and an autoencoder for dimensionality reduction. Application of random forest and XGBoost machine learning on both objects is applied to compare the performance on the two objects. To fill a methodological gap, the study implemented the developed model on the digital object dataset and its physical object equivalent to assess intrusion detection capability. The study established that the application of the developed random forest model on the use case digital object dataset varies slightly from its physical equivalent as assessed using standard performance metrics, though revealing very good performance for both objects, which validates the digital object and its applicability in the real world
NPIS, la société savante internationale dédiée à la recherche sur les interventions non médicamenteuses
No full textInternational audienceScientific societies are communities that play an essential role in healthcare systems. Their main goals are to promote knowledge and to facilitate the implementation of relevant studies in a specific field. In 2021, the Non-Pharmacological Intervention Society (NPIS), an international society, was founded with the aim of federating the energies of physical, nutritional and psychosocial prevention and care practices. The society collaborates with other scientific societies and specialist authorities on health issues. This article presents the rationale, history, missions and ambitions of the NPIS, after recalling the main missions of a scientific society in the healthcare field.Les sociétés savantes sont des communautés scientifiques qui jouent un rôle essentiel dans le fonctionnement des systèmes de santé. Elles visent à faire progresser les connaissances et les pratiques dans un domaine spécifique, et à faciliter la réalisation d’études pertinentes. C’est dans le but de fédérer les énergies dans les pratiques corporelles, nutritionnelles et psychosociales de prévention et de soin qualifiées par la HAS depuis 2011 d’interventions non médicamenteuses (INM), qu’une société savante internationale a vu le jour en 2021 en France, la Non-Pharmacological Intervention Society (NPIS). Elle collabore avec les autres sociétés savantes et les autorités spécialistes des questions de santé. Cet article présente sa justification, son histoire, ses missions et ses ambitions après avoir rappelé les principales missions d’une société savante dans le domaine de la santé
Dossier « L’évaluation des jeux sérieux sur les thématiques agro-environnementales, territoriales et alimentaires » – Évaluation, observation et réflexivité : construction de l’interdisciplinarité au moyen du codéveloppement d’un jeu sérieux
No full textInternational audienceInterdisciplinarity cannot be decreed a priori. It has to be built up gradually, through interactions between disciplinary knowledge, interdisciplinary practices and feedback. But how do we learn about interdisciplinarity? In this article, we present a process of reflective evaluation based on the co-development of a serious game for interdisciplinarity. We hypothesise that the reflective evaluation process at work in the co-development of a serious game acts as an external device likely to shake up and develop the learner’s definitions and practices. We describe the implementation of each stage of the serious game’s co-development process: in applying category theory, this involves the conceptual modelling of the reference systems of 12 volunteer researchers whose ontologies and semantic categories constitute the elements (foundations, bricks, bridges) of a game for building interdisciplinarity. By reporting on the process of reflective evaluation at work at each stage of this co-development, we discuss its impact on the learning of interdisciplinarity, the integration of the methods proposed in this learning by the learners and the improvement of the learning system as such. This experiment thus reveals the multiplicity and coexistence of evaluative intentions at the time of the experiment. It underlines the importance of reflective evaluation on the part of learners and observers alike, both in the short term of the game’s development and in the long term of the actual transformation of practices.L’interdisciplinarité ne se décrète pas a priori mais se construit progressivement, dans des interactions entre savoirs disciplinaires, pratiques interdisciplinaires et retours réflexifs. Mais comment apprendre l’interdisciplinarité ? Nous présentons dans cet article un processus d’évaluation réflexive expérimenté autour du codéveloppement d’un jeu sérieux pour l’interdisciplinarité. Nous posons l’hypothèse que le processus d’évaluation réflexive à l’œuvre dans le codéveloppement d’un jeu sérieux agit comme un dispositif externe susceptible de bousculer et de faire évoluer les définitions et les pratiques de l’apprenant. Nous décrivons ainsi les étapes du codéveloppement du jeu sérieux qui, par la mise en œuvre de la théorie des catégories, passe par la modélisation conceptuelle des référentiels de 12 chercheurs volontaires dont les ontologies et catégories sémantiques constituent les éléments (fondations, briques, passerelles) d’un jeu de construction de l’interdisciplinarité. En rendant compte du processus d’évaluation réflexive à l’œuvre à chaque étape de ce codéveloppement, nous montrons et discutons son impact sur les apprentissages de l’interdisciplinarité, l’intégration des méthodes proposées dans cet apprentissage par les apprenants et l’amélioration du dispositif d’apprentissage en tant que tel. Cette expérimentation rend ainsi compte de la multiplicité et de la coexistence d’intentions évaluatives lors du codéveloppement des jeux sérieux et souligne l’importance d’une évaluation réflexive, chez les apprenants comme chez les observateurs, dans le temps court du développement du jeu comme dans le temps long de la transformation effective des pratiques