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Minimization Method Comparison for Bi-level Optimization in the Context of Physical Collaboration
No full textInternational audienc
Can Agentic AI Transform Safety Engineering for the Development of Complex Systems?
No full textInternational audienceAs automated systems such as automated driving systems grow in complexity and include more and more AI, traditional safety engineering approaches may face increasing limitations. This position paper explores the emerging concept of Agentic AI -a system of autonomous agents capable of contributing to engineering tasks -and considers its potential implications for the development of safety-critical systems. Although initial observations suggest that such agents could support the creation and management of safety artifacts, facilitate datadriven development, and support in compliance with established safety standards, many questions remain. The purpose of the paper is to open a dialogue on the feasibility, benefits, and risks of integrating Agentic AI into safety engineering workflows. Key areas for discussion include the transparency of AI-generated outputs and the dynamics of human-AI collaboration. Rather than providing definitive answers, this paper invites further exploration and interdisciplinary engagement on the future of safety engineering in the age of intelligent agents.Note: This position paper was written with extensive use of AI.</p
Solution methods for the VRP with sharing of deliveries between producers in local food logistic
No full textInternational audienceThis study addresses the logistical challenges in Short Food Supply Chains (SFSC), where producers face high logistical costs. A new variant of the Vehicle Routing Problem (VRP) is proposed, enabling producers to share their deliveries with partner producers. With a partner producer, a producer can either drop off goods for a customer (to be served by the partner producer) or pick up goods for a customer they will visit themselves during their routes.Although solving the Vehicle Routing Problem (VRP) is a key area in optimization, with certain variants tailored to the specificities of SFSC, such as Pickup and Delivery or split deliveries, few studies address a delivery sharing aspect like this.Three heuristic methods were tested: GRASP (Greedy Randomized Adaptive Search Procedure), ILS (Iterated Local Search), and VNS (Variable Neighborhood Search), which systematically explores multiple neighborhoods. Initial results show a significant reduction in logistical costs thanks to the sharing approach, while also highlighting an imbalance in the workload distribution between producers.Mots clés -Circuits CourtsAlimentaires de Proximité, VRP, mutualisation, méta-heuristiques Résumé Cette étude traite des défis logistiques dans les Circuits Courts Alimentaires de Proximité (CCAP), où les producteurs sont confrontés à des coûts logistiques élevés. Une nouvelle variante du problème de tournées de véhicules (VRP) est proposée, permettant aux producteurs de mutualiser leurs livraisons avec d'autres producteurs partenaires. Avec un producteur partenaire, un producteur peut soit lui déposer des marchandises pour un client (que ce producteur servira), soit prendre des marchandises pour un client qu'il visitera lui-même lors de ses tournées. Bien que la résolution du Problème de Tournées de Véhicules (VRP) soit un domaine clé en optimisation, avec certaines variantes adaptées aux spécificités des CCAP, comme le Pickup and Delivery ou les livraisons fractionnées, peu d'études abordent un aspect de mutualisation des tournées comme celui-ci. Trois méthodes de résolutions approchées ont été testées : GRASP (Greedy Randomized Adaptative Search Procedure), ILS (Iterated Local Search), et VNS (Variable Neighborhood Search), qui explore plusieurs voisinages de manière systématique. Les premiers résultats montrent une réduction significative des coûts logistiques grâce à la mutualisation, et mettent en évidence un déséquilibre dans la répartition des charges entre producteurs.</div
Classification non supervisées d'acquisitions hyperspectrales codées : quelles vérités terrain ?
No full textInternational audienceWe propose an unsupervised classification method using a limited number of coded acquisitions from a DD-CASSIhyperspectral imager. Based on a simple model of intra-class spectral variability, this approach allow to identify classes and estimate reference spectra, despite data compression by a factor of ten. Here, we highlight the limitations of the ground truths commonly used to evaluate this type of method: lack of a clear definition of the notion of class, high intra-class variability, and even classification errors. Using the Pavia University scene, we show that with simple assumptions, it is possible to detect regions that are spectrally more coherent, highlighting the need to rethink the evaluation of classification methods, particularly in unsupervised scenarios.Nous proposons une méthode de classification non supervisée exploitant un nombre réduit d'acquisitions codées issues d'un imageur hyperspectral de type DD-CASSI. Partant d'une modélisation simple de la variabilité spectrale intra-classe, cette approche permet d'identifier des classes et d'estimer des spectres de référence malgré une compression par un facteur dix des données. Nous mettons en évidence ici les limites des vérités terrain couramment utilisées pour évaluer ce type de méthode : absence de définition claire de la notion de classe, forte variabilité intra-classe, voire erreurs de classification. À partir de la scène Pavia University, nous montrons qu'avec des hypothèses simples, il est possible de détecter des régions spectralement plus cohérentes, ce qui souligne la nécessité de repenser l'évaluation des méthodes de classification, notamment dans les scénarios non supervisés
Minimal Observations Inverse Reinforcement Learning for Predicting Human Box-Lifting Motions
No full textInternational audienceHeavy-load manual lifting poses a significant risk of injury, motivating the need for personalized robotic assistance. The Minimal Observations Inverse Reinforcement Learning (MO-IRL) algorithm has recently demonstrated strong capabilities in recovering underlying optimality principles from very few demonstrations of simulated robotic motions, and at a very reasonable computational cost. Building on this, the present study integrates ten biomechanically informed cost functions into a direct optimal control formulation to predict human motion during heavy-load manual box-lifting tasks. Contrary to previous literature, thanks to the computational efficiency of MO-IRL, we allow time-varying optimal weights and include a collision-avoidance constraint within the set of cost functions. This constraint represents the subject's apprehension of hitting the target table, As MO-IRL requires careful tuning of multiple hyperparameters, we employ a grid search to identify the optimal set. With this configuration, the predicted motion achieves an average accuracy of 11.5 ± 6.2deg across all joint angles, outperforming comparable methods. The inferred cost weights reveal a time-varying control strategy: initially minimizing lower-limb torques, then smoothing the motion through reduced joint accelerations and load velocity, and finally adjusting to avoid table collision. These findings show that biomechanically guided MO-IRL, coupled with direct optimal control, can accurately recover complex, constrained lifting motions while providing interpretable insights into human motor objectives, paving the way for adaptive and userspecific robotic assistance
Steady State Analysis for Kalman Filters with Poisson-Sampled Observations
No full textWe study optimal filtering for continuous-time linear stochastic systems with Poisson-sampled observation processes. For each realization of the sampled observation process, the posterior distribution is a Gaussian process whose mean and covariance are described by continuous-discrete process. We are particularly interested in analyzing the expectation of the first and second moment of the estimation error with respect to the sampling process. Using the system-theoretic properties like observability and controllability, our results provide tractable conditions on the mean sampling rate for convergence of the expected error covariance, its boundedness and convergence of expected estimation error to zero. Some comparisons are also drawn with the solution of Riccati differential equation associated with the continuous-observation process
Etude de bruit de phase des oscillateurs optoélectroniques à base de mini-résonateurs fibrés
No full textNational audienc
Integration of the evaporable spin-crossover complex [Fe(HB(1,2,4-triazol-1-yl) 3 ) 2 ] into organic field-effect transistors: towards multifunctional OFET devices
No full textInternational audienceIntegrating stimuli-responsive molecular switches into organic electronic devices opens interesting perspectives to achieve unprecedented functionalities. However, significant challenges arise in maintaining device functionalities and ensuring synergy with the molecular properties. Here, we described three different ways of incorporating thin films of the molecular spin crossover (SCO) complex [Fe(HB(1,2,4-triazol-1-yl)3)2] into an organic field-effect transistor (OFET) device. The fabrication of high-quality films was enabled by the use of vacuum thermal evaporation, which permitted the deposition of the SCO compound either on the surface of the organic semiconductor or at the semiconductor/dielectric interface. In device configurations where the SCO layer was not in contact with the conduction channel, changes in the drain-source current were observed near the spin crossover temperature, suggesting a potential synergistic effect. These results provide valuable guidance for the design and integration of bistable-material-based functional devices
Génération de soliton de cavité par self-injection locking sur un résonateur Fabry-Perot fibré avec puissance de pompe sub-100 mW
No full textNational audienceGénération de solitons par self-injection locking d'un DFB sur un résonateur Fabry-Perot fibré. Le processus de verrouillage est étudié analytiquement, incluant l'automodulation de phase. La théorie comme l'expérience révèlent un large intervalle de verrouillage assurant un accès stable à divers peignes de fréquences et un faible bruit de phase
LANGAGE DE SPÉCIFICATION PARALLEL-DEVS POUR LA MODÉLISATION : APPROCHE MATHÉMATIQUE ET GRAMMAIRE
No full textInternational audienceIn this article, we propose a new formal language called the Formal Parallel-DEVS Modeling Language (FPDEVSML) as a platform-independent specification of the Parallel-DEVS (PDEVS) formalism. The DEVS (Discrete Event Systems Specification) formalism enables the specification of discrete event models in a hierarchical and modular manner, providing a solid foundation for the modeling, simulation, and analysis of discrete systems. FPDEVSML is based on a grammar with a rigorous mathematical structure that formalizes the sets and mathematical objects used in PDEVS modeling. The main objective of the proposed approach is to provide a formal framework for specifying and analyzing a system and to improve interoperability between PDEVS simulators. FPDEVSML can be used as an intermediate target language for DSLs. The specified models can then be translated into different forms of code using code generators and then executed with various tools for model verification and execution.Dans cet article, nous proposons un nouveau langage formel, le Formal Parallel-DEVS Modeling Language (FPDEVSML), comme langage de spécification indépendante de la plateforme du formalisme Parallel-DEVS (PDEVS). Le formalisme DEVS (Discrete Event Systems Specification) permet de spécifier des modèles à événements discrets de manière hiérarchique et modulaire, offrant ainsi une base solide pour la modélisation, la simulation et l'analyse de systèmes discrets. FPDEVSML repose sur une grammaire dotée d'une structure mathématique rigoureuse qui formalise les ensembles et objets mathématiques utilisés dans la modélisation PDEVS. L'objectif principal de l'approche proposée est de fournir un cadre formel pour la spécification et l'analyse d'un système et d'améliorer l'interopérabilité entre les simulateurs PDEVS. FPDEVSML peut être utilisé comme langage cible intermédiaire pour les DSL. Les modèles spécifiés peuvent ensuite être traduits en différentes code des langages de programmation à l'aide de générateurs de code, puis exécutés avec divers outils de vérification et d'exécution de modèles