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Coupling simulation and machine learning for predictive analytics in supply chain management
No full textInternational audiencePredictive analytics is the approach to business analytics that answers the question of what might happen in the future. Although predictive information is critical for making forward-looking decisions, traditional approaches struggle to cope with the increasing uncertainty and complexity that characterise modern supply chains. Simulation is limited by insufficient timeliness, while machine learning is constrained by poor interpretability and data scarcity. Inspired by the complementary nature of simulation and machine learning, an integrated predictive analytics approach is proposed and applied to a humanitarian supply chain. By coupling simulation and machine learning, predictive models can be developed with limited historical data, and pre-crisis performance assessment can be performed to facilitate timely and informed decisions. The proposed approach enables managers to gain valuable insights into the complex evolution of the uncertain future, which also opens up the possibility of further integration with optimisation and digital twins
The Synthesis of 2′-Hydroxychalcones under Ball Mill Conditions and Their Biological Activities
No full textInternational audienceChalcones are polyphenols that belong to the flavonoids family, known for their broad pharmacological properties. They have thus attracted the attention of chemists for their obtention and potential activities. In our study, a library of compounds from 2′-hydroxychalcone’s family was first synthesized. A one-step mechanochemical synthesis via Claisen–Schmidt condensation reaction under ball mill conditions was studied, first in a model reaction between a 5′-fluoro-2′-hydroxyacetophenone and 3,4-dimethoxybenzaldehyde. The reaction was optimized in terms of catalysts, ratio of reagents, reaction time, and influence of additives. Among all assays, we retained the best one, which gave the highest yield of 96% when operating in the presence of 1 + 1 eq. of substituted benzaldehyde and 2 eq. of KOH under two grinding cycles of 30 min. Thus, this protocol was adopted for the synthesis of the selected library of 2′-hydroxychalcones derivatives. The biological activities of 17 compounds were then assessed against Plasmodium falciparum, Leishmania donovani parasite development, as well as IGR-39 melanoma cell lines by inhibiting their viability and proliferation. Compounds 6 and 11 are the most potent against L. donovani, exhibiting IC50 values of 2.33 µM and 2.82 µM, respectively, better than the reference drug Miltefosine (3.66 µM). Compound 15 presented the most interesting antimalarial activity against the 3D7 strain, with IC50 = 3.21 µM. Finally, chalcone 12 gave the best result against IGR-39 melanoma cell lines, with an IC50 value of 12 µM better than the reference drug Dacarbazine (IC50 = 25 µM)
Progress in the development of industrial scale tungsten fibre-reinforced composite materials
No full textInternational audienceCurrently, tungsten fibre-reinforced (Wf) composites are regarded as promising materials for plasma-facing components of future magnetic confinement fusion devices. In this context, tungsten fibre-reinforced tungsten (Wf/W) is being investigated as a pseudo-ductile composite material overcoming the intrinsic brittleness of bulk tungsten while tungsten fibre-reinforced copper (Wf/Cu) is being developed as a high-strength composite heat sink material. In this contribution, we discuss the current development status and the progress that has been achieved recently with respect to characterization and upscaling of the aforementioned materials.In cooperation with industry, upscaling of multifilamentary W yarn fabrication was demonstrated. Multilayered W fibre braids were made from such yarns and used for the manufacturing of 400 mm long medium-scale tungsten fibre-reinforced copper heat sink tubes. The maturity of short tungsten fibre-reinforced tungsten composites produced by powder metallurgy allowed the fabrication of flat tile mock-ups. Test procedure and first results of high heat flux tests will be are shown. Finally, we discuss the challenges and the benefits of these composites for the use in high heat flux components
Effect of Talc and Vitamin E TPGS on Manufacturability, Stability and Release Properties of Trilaurin-based Formulations for Hot-Melt Coating
No full textInternational audienceThis study was focused on one particular case of hot-melt coating with trilaurin – a solid medium-chain monoacid triglyceride. The challenge of using trilaurin as coating agent in melting-based processes is linked to its relatively low melting profile: 15.6°C (), 35.1°C () and 45.7°C (). From a process perspective, the only possibility to generate products coated with formulations composed of trilaurin is by setting thermal operational conditions above . From a material perspective, this processing possibility depends principally on trilaurin crystallisation which was investigated via a set of analytical techniques including turbidimetry, calorimetry, hot-melt goniometry, and polarised light microscopy. A highly soluble drug model substrate (sodium chloride crystals) was coated with three selected trilaurin-based formulations: (i) trilaurin, (ii) trilaurin plus talc, and (iii) trilaurin plus vitamin E TPGS and talc. Coated salt crystals were then analysed to investigate processing performance, coating quality, stability and release properties under digestion effect. The results show that firstly, talc addition promotes nucleation and crystal growth and, as a consequence, it facilitates the manufacture of trilaurin-based formulations. Secondly, the formulation of a solid triglyceride and a hydrophilic surfactant could potentially cause release instability, but formula (iii) was found to be stabilised by a mechanism whereby trilaurin crystallization enhanced in the presence of talc immobilised vitamin E TPGS in its crystal lattice. Thirdly, talc addition did not significantly influence trilaurin digestion which endows products with an immediate release in lipolytic conditions instead of an extended liberation in pure water. Nor did the addition of one or two additives alter the extent of trilaurin digestion under the conditions studied. These important findings relate to product manufacturability, stability, and release properties. A good understanding of material properties (e.g. crystallisation, polymorphism, digestibility) is essential for melt-processing, lipid coating stabilising and modulation of release profile of solid lipid-coated product, as demonstrated in this case study with trilaurin
Fracture resistance of binderless tungsten carbide consolidated by spark plasma sintering and flash sintering
No full textInternational audienceBinderless tungsten carbide (WC) consolidated by spark plasma sintering (SPS) and electrical resistance flash sintering (ERFS) has emerged as a promising alternative to materials obtained by traditional sintering methods. In this study, we investigated the influence of SPS and ERFS techniques on the mechanical properties of binderless WC. Hardness, indentation fracture resistance and elastic modulus were compared and analysed with respect to the microstructure of the resulting material. The results show that SPS tungsten carbide is harder, stiffer and denser when compared to the material produced by ERFS. Nevertheless, the fracture resistance of SPS ceramics was limited due to the lack of macroscopic toughening mechanisms. Conversely, flash-sintered tungsten carbide, consolidated by ERFS, possesses unique biphasic WC/W2C microstructures that promote crack deflection and bridging toughening mechanisms. Additionally, flash-sintered materials exhibit a more ductile character and are characterised by a lower effect of the strain gradient on the material plasticity upon indentation. This study provides valuable insights into the mechanical properties of ultra-hard monolithic ceramics, such as WC, influenced by ultrafast/flash sintering techniques
Theoretical study on the mechanochemical reactivity in Diels–Alder reactions
No full textInternational audienceMechanochemical reactions sometimes give different yields from those under solvent conditions, and such mechanochemical reactivities depend on the reactions. This study theoretically elucidates what governs mechanochemical reactivities, taking the Diels–Alder reactions as an example. Applying mechanical force can be regarded as the deformation of molecules, and the deformation in an orthogonal direction to a reaction mode can lower the reaction barrier. Here, we introduce a dimensionless cubic force constant, a mechanochemical reaction constant. It tells us how easily the deformation can lower a reaction barrier and enables us to compare the mechanochemical reactivities of different reactions. The constants correlate positively with the yields of the mechanochemical Diels–Alder reactions
Multi-Task Learning Approach for Hospital Bed Requirement Prediction
No full text© © 2025 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works.”International audienceHospital bed requirement prediction is essential for efficient healthcare resource management and delivering high-quality patient care. Unscheduled admissions significantly impact waiting times and complicate bed management strategies. In this paper, we present different a Multi-Task Learning (MTL) models to predict bed requirements for various Inpatient Departments (IPD) simultaneously. Specifically, we target prediction of daily bed requirements for patients admitted through the Emergency Department (ED). The proposed MTL approach, demonstrates significant advantages in predictive accuracy. Among implemented models, the MTL with XGBoost outperformed than other models in 11 tasks out of 12 with sMAPE, MAE and MSE values ranging from 0.185 to 0.974 and MTL with PyTorch model achieved low sMAPE value of 0.620 with 1 task. A key contribution of this paper is our simultaneous predictive approach, that considers the interaction between departments and leverages the bed occupancy data from the previous day (lag 1) to make a prediction. This methodology aims to reduce waiting time, optimize resource utilization and enhance patient flow within the hospital by following unscheduled admissions. This study demonstrates the potential of AI-driven predictive analytics in hospital resource management and emphasize the significance of MTL methodologies in predicting bed requirements
Optimisation de la maintenance en ligne aéronautique par un modèle de programmation par contraintes
No full textInternational audienceAirlines seek to optimize their maintenance to maximize the operational potential of their fleet. Their objectives are to reduce maintenance costs and optimize resource management. So-called “line maintenance” is a perspective that allows maintenance tasks to be carried out as and when required, while the aircraft is on the ground between flights. However, this type of maintenance management leads to greater complexity in scheduling, and tools are needed to assist planners. The operational planning problem for aircraft line maintenance can be described as a Resource Constrained Project Scheduling Problem (RCPSP), and a Constraint Programming (CP) model is used to solve the problem. A comparison with an industrial solver is proposed on real maintenance instances to illustrate the improvements and limitations of this approach.Les compagnies aériennes cherchent à optimiser leur maintenance pour maximiser le potentiel opérationnel de leur flotte. Leurs objectifs sont de réduire les coûts de maintenance et d'optimiser la gestion des ressources. La maintenance dite « en ligne » est une perspective qui permet de réaliser les tâches de maintenance au fur et à mesure sur les créneaux lorsque l'avion est au sol entre deux vols. Toutefois, cette gestion de la maintenance induit une plus grande complexité dans l'élaboration des plannings et des outils sont nécessaires pour assister les planificateurs. Le problème de planification opérationnelle de la maintenance en ligne aéronautique peut être décrit comme un problème à ressources restreintes (Resource Constrained Project Scheduling Problem (RCPSP)) et un modèle de Programmation Par Contraintes (PPC) est utilisé pour résoudre ce problème. Une comparaison avec un solveur industriel est proposée sur des instances réelles de maintenance pour illustrer les améliorations et limites de cette approche
A New 1,400 MPa-Class Pre-Hardened Steel Grade For Plastic Molding and Mechanical Engineering Applications
No full textInternational audiencePlastic injection moulding requires the use of mould inserts and holders made of high strength steel capable of withstanding cyclic high stresses resulting from high injection pressures. During the plastic injection process, the polymer material, made soft by a temperature of about 200-250°C, is injected into a mould and then cooled to take the desired shape. The choice of materials depends on the injected polymer and the nature of the part. High hardness and mechanical properties are required for durability (wear and fatigue resistance) while good machinability, optimal surface finish after polishing, and good thermal conductivity to remove heat dissipated during cooling of the mould parts are equally important
Decision Support Systems XIV. Human-Centric Group Decision, Negotiation and Decision Support Systems for Societal Transitions: 10th International Conference on Decision Support System Technology, ICDSST 2024, Porto, Portugal, June 3–5, 2024, Proceedings
No full textInternational audienceThis book constitutes the proceedings of the 10th International Conference on Decision Support Systems Technologies, ICDSST 2024, held in June 2024.The EWG-DSS series of International Conference on Decision Support System Technology (ICDSST) is planned to consolidate the tradition of annual events organized by the EWG-DSS in offering a platform for European and international DSS communities, comprising the academic and industrial sectors, to present state-of-the-art DSS research and developments, to discuss current challenges that surround decision-making processes, to exchange ideas about realistic and innovative solutions, and to co-develop potential business opportunities. This year the main topic was: Human-Centric Group Decision, Negotiation and Decision Support Systems for Societal Transitions.The 10 full papers included in these proceedings were carefully reviewed and selected from 29 submissions. They have been organized in topical sections as follows: Decision support tools and methods; and decision factors