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SCALING RELATIONS FOR THE CLG'S CRITICAL EXPONENTS
No full textWe consider, in any dimension, the constrained lattice gas introduced by Rossi et al., which is an exclusion process on a d-dimensional lattice following the additional constraint that only particles with at least one occupied neighbour can jump. In dimension d=2, this model features self-organized criticality at some critical density of particles. Numerical simulations predict the existence of scaling exponents close to criticality, and several relations can be derived between these exponents. The goal of this article is to give a mathematical framework for these relations, which have been numerically established in a companion article
On the Latency Trade-off Between Space and Terrestrial Clouds in Non-Terrestrial Networks
No full textInternational audienceNon-Terrestrial Networks (NTN) are poised to revolutionize 5G and 6G networks by integrating terrestrial and space-based cloud systems, enabling dynamic task allocation for optimal performance. Despite their promise, understanding the trade-offs between terrestrial and non-terrestrial edge computing architectures remains an area for improvement. This paper presents a comprehensive latency-focused trade-off analysis using a novel real-time emulation platform that accurately models terrestrial and space cloud environments. By evaluating network latency across geodesic distances from a fixed ground gateway, we delineate scenarios where terrestrial clouds excel and identify conditions under which Space Cloud architectures surpass their terrestrial counterparts. Additionally, we analyze how server placement strategies in satellite constellations impact performance, revealing the critical interplay between server distribution and latency outcomes. These findings offer actionable insights for designing and operating hybrid cloud systems, emphasizing the need for tailored architectures to maximize the potential of NTNbased edge computing.</div
Dual Embedding: A Fine-Tuned Language Model Approach for Accurate Polymer Glass Transition Temperature Prediction
No full textInternational audienc
Assessment of the Mechanical Properties of Soft Tissue Phantoms Using Impact Analysis
No full textInternational audienceSkin physiopathological conditions have a strong influence on its biomechanical properties. However, it remains difficult to accurately assess the surface stiffness of soft tissues. The aim of this study was to evaluate the performances of an impact-based analysis method (IBAM) and to compare them with those of an existing digital palpation device, MyotonPro®. The IBAM is based on the impact of an instrumented hammer equipped with a force sensor on a cylindrical punch in contact with agar-based phantoms mimicking soft tissues. The indicator Δt is estimated by analyzing the force signal obtained from the instrumented hammer. Various phantom geometries, stiffnesses and structures (homogeneous and bilayer) were used to estimate the performances of both methods. Measurements show that the IBAM is sensitive to a volume of interest equivalent to a sphere approximately twice the punch diameter. The sensitivity of the IBAM to changes in Young’s modulus is similar to that of dynamic mechanical analysis (DMA) and significantly better compared to MyotonPro. The axial (respectively, lateral) resolution is two (respectively, five) times lower with the IBAM than with MyotonPro. The present study paves the way for the development of a simple, quantitative and non-invasive method to measure skin biomechanical properties
Texturing injection molds using microelectronics techniques
No full textInternational audienceIn recent years, there has been growing interest in imparting specific properties to the surfaces of polymers. This functionalization can be achieved through microinjection molding. For the first time, this study introduces the use of {Cl2/Ar} plasma etching on an injection mold made of X38CrMoV5. However, scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDX) analyses revealed the presence of nonvolatile chlorine residues on the mold surface, which were oxidized upon exiting the reactor. Therefore, {H2}, {N2}, and {O2} plasma post-treatments were performed to reduce chlorine formation. Among these, the {H2} posttreatment was the most effective, delaying the onset of corrosion by 90 days. To further enhance this protection, a Cr/CrN bilayer was deposited on the mold surface. However, this coating was required to meet specific criteria to ensure its durability and accurate replication of the molded parts. Characterization analysis revealed that the coating uniformly covered the mold textures, demonstrated good mechanical properties, adhered well to the mold, and showed no degradation after 1000 injection cycles. Furthermore, injection tests demonstrated excellent replication of micrometric patterns on polypropylene (PP) parts
Double yielding in PA11: discriminating the mechanical contributions of the amorphous and crystalline fractions
No full textInternational audienceThe stress-strain curve of PA11 exhibits two well-distinct successive yield points during tensile deformation below Tg . This phenomenon, denoted double yielding (DY), has been observed as well in other semicrystalline polymers such as PA6 or PE. An investigation of the origin of such phenomenon and its relationship to the deformation mechanisms occurring in the amorphous and crystalline phases of PA11 has been conducted. PA11 samples were purposely modified prior to or during tensile testing and the resulting effects on the two yield points were systematically monitored. A strong link between ageing-, temperature/rate-or plasticity-induced molecular mobility in the amorphous phase and the first yield point has been established. On the other hand, the second yield point is clearly sensitive to crystalline restructuring due to annealing or slow cooling from the melt. However, it is also sensitive to changes in mobility in the amorphous phase. A thermomechanical activation model describing the DY phenomenon that predicts the non-trivial evolution of σ y2 and suggests that plastic flow in the amorphous phase must first be activated to initiate crystalline mechanisms has been proposed. More generally new insights into the complex microscopic deformation mechanisms in semicrystalline thermoplastics have been provided
Effects on LuxR‐Regulated Bioluminescence of Cyclodextrin‐Acyl‐L‐Homoserine Lactone Hybrids
No full textInternational audienceIn this work, acyl homoserine lactones (AHLs) are grafted, the most studied signaling molecules in many Gram‐negative bacteria, onto cyclodextrins (CDs) by copper‐catalyzed azide–alkyne cycloaddition “click” coupling between alkynyl‐AHLs and 6‐azido‐CDs derived from α ‐ and β‐CD, native or methylated. Attaching biomolecules onto a CD scaffold is a known strategy to enhance their properties, but designing CD‐AHL conjugates has never been reported. These molecules were fully characterized by NMR and high‐resolution mass spectrometry, and the study of their solubility and conformation reveals significant conformational changes due to the presence of the AHL appendage on the CD structure. One of the hybrids (per‐AHL‐ β‐CD, 9B) exhibits higher solubility in water than AHL and β ‐CD alone. The new CD‐AHLs conjugates are found to modulate bioluminescence in a quorum Sensing LuxR‐regulated light‐producing bacterial model, with significant variations depending on the structure. The per‐AHL‐ β ‐CD, 9B, is found to be the most active compound in the series
Modelling of anti-inflammatory treatment in the Alzheimer disease: optimal regimen and outcome
No full textInternational audienceThe application of non-steroidal anti-inflammatory drugs (NSAIDs) for Alzheimer’s disease is considered to be a promising therapeutic approach. Epidemiological studies suggest potential benefits of NSAIDs; however, these findings are not consistently supported by clinical trials. This long-standing discrepancy has persisted for decades and remains a significant barrier to developing effective treatment strategies. To assess the efficacy of NSAIDs in Alzheimer’s disease, we have developed a mathematical model based on a system of ordinary differential equations. The model captures the dynamicsof key players in disease progression, including Aβ-monomers, oligomers, proinflammatory mediators (M1 microglial cells and pro-inflammatory cytokines), and anti-inflammatory mediators (M2 microglial cells and anti-inflammatory cytokines). The effects of NSAIDs are modeled through a reduction in the production rate of inflammatory cytokines (IC). While a single NSAID administration temporarily reduces IC levels, their concentration eventually returns to baseline due to drug elimination. The return time depends on the drug dose, resulting in a patient-specific return time function. By analyzing this function, we propose an optimal treatment regimen and identify conditions under which NSAID treatment is most effective in reducing IC levels. Our results suggest that NSAID efficacy in Alzheimer’s disease is influenced by the stage of the disease (with earlier intervention being more effective), patient-specific parameters, and the treatment regimen. The approach developed here can also be generalized to evaluate the efficacy of anti-inflammatory treatments for other diseases
Faust Autodiff: Towards Audio Domain-Specific Machine Learning
No full textInternational audienceDifferentiable programming via automatic differentiation (AD) is the foundation for gradient-based optimisation techniques, and forms the basis for many current approaches to machine learning. Though well catered-for in general-purpose programming languages, the availability of AD in a domain-specific language (DSL) could offer novel perspectives on optimisation problems in the field of audio. We present a general scheme for differentiable programming in the Faust programming language, a high-performance DSL tailored to audio synthesis and signal processing. Faust's rich ecosystem, coupled with a comprehensive AD implementation, can provide support for audio optimisation and machine learning applications on a multitude of platforms, from FPGAs to the web
