Portail des publications scientifiques IMT Mines Alès
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Simultaneous Backward Reduction algorithm for disassembly lot-sizing under random ordering lead time
No full textInternational audienceIn order to meet item demands, end-of-life (EOL) product and subassembly ordering and disassembly schedules are determined by disassembly lot sizing, which is the subject of this study. We take into consideration a stochastic version with undetermined ordering lead time (OLT). In this case, OLT stands for the amount of time that passes between placing and receiving an order (we can only order EOL products). Throughout the planning horizon, scenarios are used to model the stochasticity. The objective is to reduce the expected total of setup, purchasing, inventory, and backlog expenses. This is achieved by expressing the problem as a two-stage mixed integer linear programming (2S-MILP) model across all potential scenarios. The 2S-MILP is unsolvable since it is predicated on every scenario conceivable. A Simultaneous Backward Reduction approach is proposed to make it tractable. To confirm the suggested method’s efficacy, it is assessed in a variety of environments
Does pain disrupt group dynamics? Impact of an unpleasant stimulation on group synchronization and its affective and affiliative consequences
No full textInternational audienceBehavioral synchrony is an important motor component of social interactions that attracted considerable attention considering its association with affiliation and positive affective states. Interestingly, moving in synchrony is associated with endorphin and oxytocin releases, two neurotransmitters associated with social connectedness and modulation of pain sensation. Consequently, synchronous motor interactions can help foster social connectedness and pain relief for individuals at risk of social isolation such as those suffering from chronic pain. A study is currently being conducted investigating the impact of electrodermal stimulation on group synchronization and its affective and affiliative consequences. Groups of 5 participants execute synchronous movement in different conditions measuring (i) their “natural” frequencies, (ii) baseline group synchronization, and (iii - iv) the impact of an unpleasant stimulation on group synchronization and its recovery. Participants’ movements are recorded using a 3-D infra-red camera system and their physiological state is monitored with electrocardiograms. Self-reports measure the impact of synchronization and its disruption on affective states and social connectedness. Using the Kuramoto model, modulation of movement synchronization across experimental conditions is investigated as well as modifications of participants’ kinematics profiles (i.e., velocity, acceleration and amplitude modulations). Finally, the impact of the perturbation is also explored on the modulation of participants’ physiological states and self-reports of affective and social connectedness.This study will improve our understanding of the influence of pain on group dynamics and kinematics profiles. Results will nurture the development of virtual agents driven by an AI architecture capable of transforming kinematics features for alleviating pain and enhancing social connectedness for individuals suffering from chronic pain conditions
Analysis of digital twin and its physical object: Exploring the efficiency and accuracy of datasets for real-world application
No full textInternational audienceThe concept of digital twin (DT) has recently gained popularity due to its ability to create a virtual representation of systems in order to improve the performance of its cyber-physical counterpart. This study compares and analyses datasets of DTs and their corresponding physical objects to determine the effectiveness and dependability of DT technology for practical applications. The research aims to proffer a framework for ascertaining the level of (dis)similarity between a physical object and its DT equivalent. A study of water distribution (WADI) is put into perspective. Findings revealed that the proffered framework presents a method for ascertaining a (dis)similarity level (considering datasets) of a physical object and its DT using adequate statistical tests
Evaluation de la qualité des représentations numériques compatibles avec les préférences du décideur
No full textNational audienceDans les problèmes de décision multicritère, le choixde la représentation numérique de la fonction de valeurs,parmi celles compatibles avec les préférences dudécideur, est souvent arbitraire. De plus, pour une fonctionde valeurs basée sur une intégrale de Choquet où lenombre de critères est très grand, il est difficile pour ledécideur de fournir des informations sur ses préférencesqui soient à la fois en quantité très large et en même tempsreprésentatives. Dans cet article, afin d’éviter un choix arbitraire,nous proposons des indicateurs qui permettentd’évaluer la qualité des représentations numériques enfonction de certaines propriétés attendues comme lacohérence, la robustesse, et la préservation de l’ordre.Enfin, nous proposons une application de ces indicateurspour une méthode de désagrégation présentée dansla littérature. Il s’agit d’établir un classement de 100représentations numériques identifiées par cette méthoderelativement aux indicateurs proposés
Evaluation of biochar for removal of micropollutants in bioaugmented constructed wetlands
No full textNational audiencePharmaceuticals and pesticides are common contaminants in water bodies worldwide,posing significant threats to the environment and to human and animals’ lives. Traditionalwastewater treatment processes often struggle to effectively remove these complex pollutants,imposing the examining of alternative treatments strategies. CWs have been developed asa low-cost and green technology to improve water quality as tertiary treatment but still failin removing completely some micropollutants. Coupling adsorbent materials to CWs mayrepresent a good solution, bringing a final polishing step. For that, biochar, a carbonaceousmaterial derived from biomass pyrolysis, has appeared as a promising approach for contam-inant removal due to its high adsorption capacity, surface area, and porosity.The project SAFE aims to enhance water quality by implementing a cost-effective, natural-based solution capable of being reused for agricultural crop irrigation. Thus, this studyfocuses on a comprehensive evaluation of a specific biochar’s properties, emphasizing itsabilities in adsorbing and desorbing pharmaceuticals and pesticides. Seven pharmaceuticals(sulfamethoxazole, trimethoprim, clarithromycin, clindamycin, azithromycin, venlafaxine,and metoprolol) and one pesticide (fipronil) were selected for this study using a methodol-ogy based on four criteria (occurrence, persistence, bioaccumulation, and toxicity, OPBT)expressed in terms of concentrations in the secondary effluent. The characterization phase ofthis study results in analyzing the selected biochar to determine its adsorption and desorptionproperties regarding targeted compounds. This research assesses the retention capacity ofeach compound through adsorption tests and examines saturation through desorption teststo determine equilibrium points within the biochar. Furthermore, it connects them withregeneration studies employing oxidants (e.g., peroxymonosulfate), using synthetic wastew-ater and distilled water as model systems, to evaluate the biochar’s efficacy in removing andreleasing contaminants. The experiments investigate the influence of factors such as initialconcentration, contact time, on adsorption and desorption equilibrium
Experimental characterization of SVOC cotton/air partitioning in Micro-Chamber/Thermal Extractor
No full textInternational audienceIndoor exposure to semi-volatile organic compounds (SVOCs) is known to be influenced by their partition between air, particles, and surfaces. Due to their low volatility, phthalates, alternative plasticizers, and organophosphate ester flame retardants (OPEFRs) are found on objects, clothes, and occupants’ skin. Children are particularly susceptible to the effects of endocrine-disrupting SVOCs due to their behavior.Cotton textiles are used as curtains, bedding, and clothing. Therefore, cotton can be considered both an SVOC sink and a medium through which they can diffuse to the skin, increasing dermal exposure.This work aims to develop an experimental procedure to estimate the partition coefficients (Kcotton/air) of potentially harmful SVOCs between cotton and air in a Micro-Chamber/Thermal Extractor. A commercial PVC furniture covering containing TPP, EHDPP, and DINCH is placed on the walls of the cells (including the lid surface) as an SVOC source. A cotton curtain sample is placed in the cell until a stable concentration of SVOCs in the air is reached (yeq, sampled at the micro-chamber outlet by Tenax tubes). The surface concentration (qeq) is then obtained by Accelerated Solvent Extraction.The cotton/air equilibrium is described by a Langmuir isotherm: Kcotton/air=qeq/yeq. At 40°C, the results are 500 m, 800 m, and 1700 m for TPP, EHDPP, and DINCH, respectively, in accordance with previously published data for stainless steel.This method could be applicable to sink surface of any material. Further measurements are planned to confirm the suitability of dynamic conditions for determining a linear surface/air partition coefficient
Targeted and untargeted analysis of semivolatile organic compounds (SVOCs) in indoor dust from 10 French sports halls
No full textInternational audienceThe indoor air quality of sports halls has been poorly studied so far. Within the QAI Sport project, dust samples collected in 10 sports halls were analysed for target and non-targeted SVOCs. The results show high concentration of SVOCs (> mg/g), particularly in dojos, mo-tricity rooms, and weight rooms. The most abundant substances were DiNP > DEHP> BBP> DiBP> TPP> EHDPP> TBEP> TDCPP > benzophenone. This contamination needs to be fur-ther investigated to evaluate if it is a public health issue
Model Based Systems Engineering applied to Digital Twin engineering: why and how to?
No full textInternational audienceIn addition to inheriting concepts and methodological principles from System Engineering, Model-Based Systems Engineering (MBSE) emphasizes the role of modelling and models in engineering processes. Different types of models are then constructed and used, each being a digital representation of a system that is undeniably partial, but also necessary. It highlights and enables the analysis of certain characteristics of this system, e.g. its behaviour, its functions or its composition to make relevant design choices. Digital Twins are the ultimate representation of a system, expected to be faithful and realistic for the purpose they serve, as well as to be connected and synchronized to the modelled physical asset. Hence, they support stakeholders to manage, train or optimize the target system when implemented and put into operation. However, defining and engineering Digital Twins remains a difficult process, with little methodology available to build and ensure it remains faithful to a continuously evolving reality. MBSE provides concepts and a methodological framework that are well adapted to solve complex engineering problems with many constraints. This position paper introduces a MBSE based Digital Twin engineering framework foundation, applied to an manufacturing system
Leveraging a Microservice Architecture, Access Control and Interoperability Patterns to Manage Privacy-related User Consents
No full textShort paperInternational audienceConsent management is of paramount importance when processing personal data. It is now prescribed as mandatory by regulations such as the GDPR. This article presents a micro-service architecture providing a protocol for access control including authentication, authorization management, and externalized consent management based on the ABAC (Attribute-Based Access Control) and the side-car architecture patterns. The experimentation on a case example validates that its integration is light and non intrusive for existing applications
