Design of proportional integral observer‐based resilient control for periodic piecewise time‐varying systems: The finite‐time case

International audienceThe prime intent of this study is to scrutinize the state estimation and finite‐time (FT) stabilization problems for a class of periodic piecewise time‐varying systems (PPTVSs) in the presence of external disturbances, immeasurable states and gain fluctuations by dint of resilient control. Moreover, the proportional integral observer system is built in line with the output of the PPTVSs to reconstruct the states of the PPTVSs, since the state dynamics of the system are often not measurable. Meanwhile, the output signals are quantized with the use of a logarithmic quantizer prior to being fed into the constructed observer systems. Further, the fluctuations in the controller and observer gain matrices are considered to occur in a random manner and they pursue the pattern of a Bernoulli distributed white sequence. Subsequently, by means of Lyapunov stability theory and the matrix polynomial lemma, the adequate requirements for ascertaining the FT boundedness and IO‐FT stabilization of the addressed system are procured in the context of linear matrix inequalities. Thereupon, on the premise of the established criteria, the gain matrices of the controller and observer are obtained. Ultimately, the simulation results have been showcased including the mass spring damper system to exemplify the efficacy and usefulness of the theoretical conclusions drawn

CFD simulation of pollutant dispersion using anisotropic models: Application to an urban like environment under neutral and stable atmospheric conditions

International audienceModeling the atmospheric dispersion of pollutants emitted from different types of sources under various atmospheric conditions is an essential prerequisite for risk assessment studies and emergency preparedness. In this study, we evaluate the performance of different turbulence models and velocity-scalar correlation models implemented in the Code_Saturne. The evaluation is done with observations of four trial cases of the Mock Urban Setting Test (MUST) campaign in an urban type environment and in neutral and stable atmospheric conditions. For all of the trials studied, the CFD model with a first-order closure model (ɛ) predicts 61.1% of the concentrations within a factor of two of the observations, which is higher than the percentage of predicted points (58.8%) when a second-order closure model (ɛ) is used. Overall, the CFD model underestimates observed concentrations, regardless of the turbulence model used. For the trial with slightly stable conditions, the results show that the ɛ model combined with an algebraic SGDH model predicts 75% concentrations within a factor of two of the observations. The performance of the ɛ model is compared to that of the ɛ model when used with the algebraic SGDH, GGDH models and with the scalar flux transport equation (DFM model). Under slightly stable atmospheric conditions, the DFM model predicts 69% of concentrations within a factor of two of observations, showing promise for modeling under these conditions, despite its relatively high computational cost

Modeling compartmentalization within intracellular signaling pathway

We present a novel approach to modeling receptor-activated signaling pathways that take into account the compartmentalization of receptors and their effectors, both on the cell surface and in dynamic intracellular vesicles called endosomes. The first building block of the model concerns compartment dynamics. It takes into account creation of de novo endosomes, i.e. endocytosis, and further recycling of endosomes to the cell surface or degradation, as well as fusion of endosomes via coagulation dynamics. The second building block concerns biochemical reactions on the cell surface and within intra-cellular compartments. Both building blocks are coupled by the transfer of molecules that occurs at each event that modifies the compartments.The model is formulated as a integro-partial differential equation, with transport and coagulation operators, and source terms, coupled to an integro-differential equation. In this work, we prove sufficient conditions to obtain exponential ergodicity for the size distribution of intracellular compartments. We further design a finite volume scheme to simulate our model. Finally, we show two application cases that show qualitative agreement with recently published data, proving that our model can help capture the spatio-temporal complexity of receptor-activated signaling pathway.Nous présentons une nouvelle approche de modélisation des voies de signalisation activées par les récepteurs, qui prend en compte la compartimentation des récepteurs et de leurs effecteurs, à la fois à la surface cellulaire et dans des vésicules intracellulaires dynamiques appelées endosomes. Le premier élément constitutif du modèle concerne la dynamique des compartiments. Il prend en compte la création d'endosomes de novo, c'est-à-dire l'endocytose, puis le recyclage des endosomes à la surface cellulaire ou leur dégradation, ainsi que la fusion des endosomes via une dynamique de coagulation. Le deuxième élément constitutif concerne les réactions biochimiques à la surface des cellules et dans chaque compartiment intracellulair. Les deux parties du modèles sont couplées par le transfert de molécules qui se produit à chaque événement modifiant les compartiments.Le modèle est formulé comme une équation aux dérivées partielles avec terme intégrale, avec des opérateurs de transport, de coagulation et des termes sources, couplée à une équation intégro-différentielle. Dans ce travail, nous prouvons des conditions suffisantes pour obtenir une ergodicité exponentielle pour la distribution en taille des compartiments intracellulaires. Nous concevons en outre un schéma de volumes finis pour simuler notre modèle. Enfin, nous montrons deux cas d'application qui montrent un accord qualitatif avec des données publiées récemment, prouvant que notre modèle peut aider à capturer la complexité spatio-temporelle de l'activation des voies de signalisation

« Engagements au travail et capitalisme transnational »

International audienceAnalyses of global capitalism present at times transnational corporations as anonymous and invincible giants that have wiped out any kind of citizenship at work. The articles in this special issue of Cultures & Conflits, rather, present a variety of forms of (dis)engagement at work, from trade unionism to corporate volunteering, from whistle-blowing to disinvestment. By paying attention to the empirical thickness of social relations within the sphere of production, as well as to the normative infrastructures and political processes that condition them, the special issue argues for a political sociology perspective of engagement at work. It shows that the forms of engagement, as well as disengagement, are forged at the intersection of the labour process, localized legal and political orders, and the social property of workers, with the “local” and the “global” less as preexisting realities than as ways of articulating these three dimensions.L’analyse du capitalisme global tend parfois à présenter les grandes firmes transnationales comme des colosses anonymes et invincibles ayant anéanti toute forme de citoyenneté au travail. Les articles rassemblés dans ce numéro de Cultures & Conflits donnent plutôt à voir une pluralité de figures d’engagement, du syndicaliste au bénévole d’entreprise, du lanceur d’alerte au travailleur désinvesti. En prêtant attention à l’épaisseur empirique des rapports sociaux qui se nouent dans la sphère de la production, ainsi qu’aux infrastructures normatives et aux processus politiques qui les conditionnent, le dossier défend la perspective d’une sociologie politique des engagements au travail. Il montre que les formes de l’engagement – ou du désengagement – se configurent au croisement du procès de travail, des ordres politicojuridiques localisés et des propriétés sociales des salariés, le « local » et le « global » étant moins des données de départ que des modalités d’articulation de ces trois dimensions

Affine Volterra processes with jumps

International audienceThe theory of affine processes has been recently extended to continuous stochastic Volterra equations. These so-called affine Volterra processes overcome modeling shortcomings of affine processes by incorporating path-dependent features and trajectories with regularity different from the paths of Brownian motion. More specifically, singular kernels yield rough affine processes. This paper extends the theory by considering affine stochastic Volterra equations with jumps. This extension is not straightforward because the jump structure and possible singularities of the kernel may induce explosions of the trajectories. This study also provides exponential affine formulas for the conditional Fourier-Laplace transform of marked Hawkes processes

‘Structural arrangements for open innovation: a comparative analysis of Chinese and French multinational companies’

FNEGE 3, HCERES B, ABS 2International audienceThe ‘structural perspective' of OI, outlines the role of the structural arrangements of companies in supporting open practices. Paradoxically, the understanding of the arrangements of companies that are dedicated to openness remains under-investigated. In this perspective, this article focuses on specific arrangements that are related to the inside-out and outside-in processes. The analysis also emphasises the structural arrangements dedicated to Intellectual Property Rights (IPRs), in so far as IPRs are considered as key tools for openness. Based on four cases in Western (French) and emerging (Chinese) contexts we answer the following research question: what are the company’s structural arrangements dedicated to the inside-out and outside-in OI processes? The results outline the existence of common characteristics whatever the OI process regarding the links between top management and innovation entities, structural arrangements dedicated to evaluation, knowledge management and decision making may be. The results emphasize the existence of specific arrangements for each process related to IPR management. These findings contribute: to the structural theories of innovation by proposing the first comprehensive approach to the structural perspective for OI processes; to innovation ambidextry which has never been documented in OI; to the recent literature on the contextual dimension of OI deployment

Ce que les appels à projets du Plan d’investissement dans les compétences font à l’accompagnement vers l’emploi

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Prescribed-Time Adaptive Fuzzy Optimal Control for Nonlinear Systems

International audienceThe prescribed-time optimal control problem for nonlinear systems is investigated in this paper. First, a transformation function is constructed, which includes the system state and a strictly decreasing auxiliary function related to the prescribed time and accuracy. Second, the control input and the transformation function are incorporated into a new performance index function (PIF). This encodes the prescribed-time control into the optimal control problem. Subsequently, a new Hamilton-Jacobi-Bellman (HJB) equation related to the prescribed time and accuracy is derived. To find a solution to the HJB equation, a fuzzy reinforcement learning algorithm is proposed. This algorithm successfully approximates the optimal cost and control policy while ensuring the system stability. Additionally, the system state can converge to a pre-assigned residual set within a prescribed time. Finally, an example of an electromechanical system is used to illustrate the efficacy of the suggested algorithm

La délégation incertaine et l’inopposabilité des exceptions ?, note sous Cass. 3e civ., 23 nov. 2023, n° 22-17.027

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L’Oracle du Caire, vol. 3, L’émir des attentats (roman)

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