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Red blood cells rheology measured using AFM. A comparison with other studies
No full textInternational audienc
Capacity in high dimensional percolation
No full text42p.We introduce a notion of capacity for high dimensional critical percolation by showing that for any finite set A, the suitably rescaled probability that the cluster of z intersects A converges as ∥z∥ → ∞. This can be viewed as a generalisation of the asymptotic of the two point function and we call the limit the p-capacity of A. We next show that the probability that the Incipient Infinite Cluster of z intersects the set A appropriately normalised is also of order the p-capacity of A as ∥z∥ → ∞. We conjecture that the p-capacity is of the same order as the (d -4)-Bessel-Riesz capacity and in support of this we estimate the p-capacity of balls. As a byproduct of our techniques we give a simpler proof of the one-arm exponent of Kozma and Nachmias for dimensions 8 and higher and as long as the two point function asymptotic holds. Our proofs make use of a new large deviations bound on the pioneers, that is the number of points on the boundary of a box which are part of the cluster of the origin restricted to this box
Contribution à la définition des enjeux et verrous de la soutenabilité en électronique de puissance
No full textInternational audienceThe GT-CEPPS (Working Group on More Sustainable Electronic Power Converters) of the GDR SEEDS (Electrical Energy Systems in their Societal Dimensions) presents here the results of its work on the challenges and obstacles to sustainability in power electronics. The work focuses on two aspects of the topic: tools, methods and indicators on the one hand, and circular design on the other. The analysis is structured into four levels corresponding to degrees of difficulty, transformation and societal acceptability. At each level, the challenges and obstacles are described and then translated into avenues for research activities. The whole is contextualised and illustrated through ongoing activities at national and European level.Le GT-CEPPS (Groupe de travail -Convertisseurs Electroniques de Puissance Plus Soutenables) du GDR SEEDS (Systèmes d'Energie Electrique dans leur Dimensions Sociétales) présente ici le fruit de son travail de réflexion autour des enjeux et verrous de la soutenabilité en électronique de puissance. Le travail porte sur deux facettes de la thématique, les outils, méthodes, indicateurs d'une part, et la conception en vue de la circularité d'autre part. L'analyse est structurée en quatre niveaux qui correspondent à des échelons de difficulté, de transformation et d'acceptabilité sociétale. Dans chaque niveau, des enjeux et des verrous sont décrits et ensuite traduits en pistes d'activités de recherche. L'ensemble est contextualisé et illustré via les activités en cours aux échelles nationale et européenne
Real-time analysis of cell secretions through plasmonic nanohole array immunosensor integrated in a microfluidic platform
No full textInternational audienc
Dual-time stepping technique for ALE-SPH scheme
No full textThe Arbitrary Lagrangian Eulerian Smoothed-Particle Hydrodynamics (ALE-SPH) method presents a formalism that is particularly well suited in simulating free surface flows. However, to be accurate and stable, the simulation time steps should be small because the time integration is usually performed explicitly. The challenge is to improve its stability even for complex simulations such as the operation of Pelton turbines.A new method called ALE-DTS-SPH that has a temporal multi-resolution formalism is proposed in this work. The ALE-SPH formalism has been revised according to the Dual-Time Stepping (DTS) technique in order to ensure its unconditional temporal stability. The simulations can thus be conducted with larger time steps. Furthermore, by taking advantage of the pseudo-timescale introduced, a particle shifting strategy has been implemented to improve the consistency of the numerical scheme without changing the physical properties of the flow.The relevance of the ALE-DTS-SPH method is deemed robust on a set of complementary academic test cases. At first, the Taylor-Green vortices case is performed with satisfactory results in comparison with analytical solution. Then, the results obtained for the simulation of an impinging jet on a flat plate are satisfactory. All in all, by comparison with the standard ALE-SPH approach, the proposed method improves the results accuracy and robustness.</div
Recommendation and explanation in road safety: a holistic exploration of multifaceted road risk
No full textInternational audienceTackling the global challenge of road safety, which tragically continues to take a significant toll on lives, requires innovative strategies based on new technologies such as Artificial Intelligence and the Internet of Things, among others. This paper introduces a comprehensive approach that blends subjective citizen perceptions with objective data for thorough road risk analysis. Providing a multifaceted perspective on road safety aims to enhance risk management effectively. The approach focuses on understanding current risks through risk assessment and anticipating future risks via predictive analysis, both crucial for proactive risk mitigation. Additionally, it offers nuanced insights into road risk dynamics, helping recommend safer routes and refine urban planning strategies. Employing explainable machine and deep learning techniques ensures transparency in risk factors, thereby transforming road safety policies and practices. This integrated approach shows potential for yielding positive outcomes in both communities and urban environments
Modeling Energy Consumption in Deep Learning Architectures Using Power Laws
No full textInternational audienceModern Deep Learning architectures such as LSTM, GRU, and Transformers achieve remarkable performance in various sequence processing tasks. Yet, their high computational cost and energy consumption have raised concerns about their environmental impact and the sustainability of Deep Learning. In this paper, we present an empirical study assessing the efficiency of training LSTM, GRU, and Transformer models on a GPU. By evaluating these models under various configurations, we characterize the relationship between energy consumption and pre-defined quantities such as hardware efficiency and the number of floating point operations (FLOPs) required for inference. We show that it is possible to derive scaling laws that make energy consumption predictable, given an architecture and a GPU model.</div
Interlaboratory validation of an optimized protocol for measuring α-amylase activity by the INFOGEST international research network
No full textInternational audienceThe activity of α-amylases is frequently determined using a single-point assay at 20 °C. Previous work within INFOGEST "Working Group 5 -Starch digestion and amylases" identified significant interlaboratory variation with this protocol. The current study aimed to evaluate the repeatability (intralaboratory precision) and reproducibility (interlaboratory precision), measured as coefficients of variation (CVs), of a newly optimized protocol version based on four time-point measurements at 37 °C. Human saliva (a pool from ten healthy adults) and three porcine enzyme preparations (two pancreatic α-amylases and pancreatin) were tested in 13 laboratories across 12 countries and 3 continents. Assay repeatability for each lab remained below 20% for all test products and the overall repeatability was below 15%, ranging between 8 and 13% for all products. Reproducibility was greatly improved with interlaboratory CVs ranging from 16 to 21%, i.e. up to four times lower than with the original method. Five laboratories repeated the same assay at 20 °C, and the amylolytic activity of each product increased by 3.3-fold (± 0.3) from 20 to 37 °C. The newly optimized protocol is henceforth recommended to ensure precise determinations of α-amylase activity levels and to facilitate comparisons across different studies
Hardware implementation of tunable fractional-order capacitors by morphogenesis of conducting polymer dendrites
No full textInternational audienceConventional electronics is founded on a paradigm where shaping perfect electrical elements is done at the fabrication plant, so as to make devices and systems identical, “eternally immutable.” In nature, morphogenic evolutions are observed in most living organisms and exploit topological plasticity as a low-resource mechanism for in operando manufacturing and computation. Often fractal, the resulting topologies feature an inherent disorder: a property that is never exploited in conventional electronics manufacturing, while necessary for data generation and security in software. In this study, we present how such properties can be exploited to implement long-term and evolvable synaptic plasticity in an electronic hardware. The rich topology of conducting polymer dendrites (CPDs) is exploited to program the non-ideality of their electrochemical capacitances containing constant-phase-elements. Their evolution through structural changes alters the characteristic time constants for them to charge and discharge with the applied voltage stimuli. Under a train of voltage spikes, the evolvable current relaxation of the electrochemical systems promotes short-term plasticity, with timescales ranging from milliseconds to seconds. This large window depends not only on the temporality of the voltage pulses used for reading but also on the structure of a pair of CPDs on two electrodes, grown by voltage pulses. This study demonstrates how relevant physically transient and non-ideal electrochemical components can be exploited for unconventional electronics, with the aim to mimic a universal property of living organisms, which could barely be replicated in a silicon monocrystal