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Améliorer l'acquisition de connaissances techniques avec les systèmes RAG : le cas de la TEI
No full textInternational audienceIn an era dominated by an explosion of technical documentation across diverse domains, the need for effective knowledge acquisition mechanisms has become paramount. The assimilation of the "Text Encoding Initiative" (TEI) guidelines, for instance, presents challenges for organizations and individuals seeking to effectively adopt its encoding principles. Retrieval-Augmented Generation (RAG) systems emerge as a promising paradigm to address this challenge, seamlessly integrating information retrieval with natural language generation to facilitate the acquisition of technical knowledge from large documentation material. In this publication, we explore how RAG systems can mitigate these challenges while maximizing the benefits of TEI adoption, particularly in the context of learning and implementation.Challenges in learning and adopting TEI guidelines [1] revolve around the complexity of the markup language and the diverse skill levels of users. Mastering TEI requires familiarity with its intricate syntax, encoding conventions, and domain-specific applications, posing a steep learning curve for novices. Furthermore, the extensive volume of its published guidelines poses another challenge, even for experienced users, in efficiently retrieving relevant information.</div
Impact of a two-dimensional steep hill on wind turbine noise propagation
No full textInternational audienceAbstract. Wind turbine noise propagation in a hilly terrain is studied through numerical simulation in different scenarios. Linearized Euler equations are solved in a moving frame that follows the wavefront, and wind turbine noise is modeled with an extended moving source. We employ large-eddy simulations to simulate the flow around the hill and the wind turbine. The sound pressure levels (SPLs) obtained for a wind turbine in front of a 2D hill and a wind turbine on a hilltop are compared to a baseline flat case. First, the source height and wind speed strongly affect sound propagation downwind. We find that topography influences the wake shape, inducing changes in the sound propagation that drastically modify the SPL downwind. Placing the turbine on the hilltop increases the average sound pressure level and amplitude modulation downwind. For the wind turbine placed upstream of a hill, a strong shielding effect is observed. But, because of the refraction by the wind gradient, levels are comparable with the baseline flat case just after the hill. Thus, considering how terrain topography alters the flow and wind turbine wake is essential to accurately predict wind turbine noise propagation
Quadcopters in Smart Agriculture: Applications and Modelling
No full textInternational audienceDespite technological growth and worldwide advancements in various fields, the agriculture sector continues to face numerous challenges such as desertification, environmental pollution, resource scarcity, and the excessive use of pesticides and inorganic fertilizers. These unsustainable problems in agricultural field can lead to land degradation, threaten food security, affect the economy, and put human health at risk. To mitigate these global issues, it is essential for researchers and agricultural professionals to promote advancements in smart agriculture by integrating modern technologies such as Internet of Things (IoT), Unmanned Aerial Vehicles (UAVs), Wireless Sensor Networks (WSNs), and more. Among these technologies, this paper focuses on UAVs, particularly quadcopters, which can assist in each phase of the agricultural cycle and improve productivity, quality, and sustainability. With their diverse capabilities, quadcopters have become the most widely used UAVs in smart agriculture and are frequently utilized by researchers in various projects. To explore the different aspects of quadcopters’ use in smart agriculture, this paper focuses on the following: (a) the unique advantages of quadcopters over other UAVs, including an examination of the quadcopter types particularly used in smart agriculture; (b) various agricultural missions where quadcopters are deployed, with examples highlighting their indispensable role; (c) the modelling of quadcopters, from configurations to the derivation of mathematical equations, to create a well-modelled system that closely represents real-world conditions; and (d) the challenges that must be addressed, along with suggestions for future research to ensure sustainable development. Although the use of UAVs in smart agriculture has been discussed in other papers, to the best of our knowledge, none have specifically examined the most popular among them, “quadcopters”, and their particular use in smart agriculture in terms of types, applications, and modelling techniques. Therefore, this paper provides a comprehensive survey of quadcopters’ use in smart agriculture and offers researchers and engineers valuable insights into this evolving field, presenting a roadmap for future enhancements and developments
About mechanically induced crystallization kinetics in filled natural rubber
No full textInternational audienceIn this work, we provide information about mechanically induced crystallization (MIC) kinetics. First, we show that the usual definition of threshold elongations for crystallization and melting does not always make sense. We then show the effect of the loading path on the crystallization levels reached. Finally, we define a quantity representative of the crystallization kinetics and try to describe it using quantities as elongation or stress. At the same time, we illustrate that crystallization is a self-regulating phenomenon: a saturation of crystallization kinetics can be reached
A posteriori error estimates for the DD+ jumps method on the Neutron Diffusion equations
No full textWe analyse a posteriori error estimates for the discretization of the neutron diffusion equations with a Domain Decomposition Method, the so-called DD+ jumps method. We provide guaranteed and locally efficient estimators on a base block equation, the one-group neutron diffusion equation. Classically, one introduces a Lagrange multiplier to account for the jumps on the interface. This Lagrange multiplier is used for the reconstruction of the physical variables. Remarkably, no reconstruction of the Lagrange multiplier is needed to achieve the optimal a posteriori estimates
Forward-Backward Turbo Equalization for Underwater Communication Systems
No full textInternational audienceThis paper proposes a novel equalization algorithm for underwater communication. It performs iteratively adaptive equalization and channel decoding in order to reduce intersymbol interference (ISI). In particular, our proposed forward-backward turbo equalizer uses two sparse feedforward-feedbackward equalizers operating in opposite time directions, each sparse equalizer performing jointly phase synchronization to enhance the overall performance. Our simulations, both on synthetic and real underwater channels validate the effectiveness of the proposed scheme as they show a considerable gain compared to the conventional adaptive turbo equalization algorithm.</div
Ultrafast nonthermal transient reduction in conductivity
No full textInternational audienceThis work presents findings from femtosecond time-resolved spectroscopy on LaVS3, revealing interactions between carriers and phonon modes. It elucidates the effects on thermal conductivity and the emergence of metastable states due to carrier trapping within vanadium clusters
Capacité portante des fondations superficielles sur sol renforcé par inclusions rigides
No full textInternational audienceThis study concerns the determination of the bearing capacity of shallow foundations on reinforced soil with rigid inclusions using the kinematic exterior approach of the yield design. A comparison between the estimated bearing capacity and the sum of the individual bearing capacities of the inclusions and the footing reveals that the latter results in a significant overestimation. Reduction factors arising from the load's inclination and eccentricity are also studied.Cette étude porte sur la détermination de la capacité portante des fondations superficielles sur sol renforcé par inclusions rigides via l'approche cinématique du calcul à la rupture. Une comparaison entre la capacité portante estimée et la somme des capacités portantes individuelles des inclusions et de la semelle révèle que cette dernière donne une surestimation significative. Des facteurs correcteurs liés à l'inclinaison et à l'excentrement de la charge sont également étudiés
Cyclogenesis in the Tropical Atlantic: First Scientific Highlights from the Clouds–Atmospheric Dynamics–Dust Interactions in West Africa (CADDIWA) Field Campaign
No full textInternational audienceDuring the boreal summer, mesoscale convective systems generated over West Africa propagate westward and interact with African easterly waves, and dust plumes transported from the Sahel and Sahara by the African easterly jet. Once off West Africa, the vortices in the wake of these mesoscale convective systems evolve in a complex environment sometimes leading to the development of tropical storms and hurricanes, especially in September when sea surface temperatures are high. Numerical weather predictions of cyclogenesis downstream of West Africa remains a key challenge due to the incomplete understanding of the clouds–atmospheric dynamics–dust interactions that limit predictability. The primary objective of the Clouds–Atmospheric Dynamics–Dust Interactions in West Africa (CADDIWA) project is to improve our understanding of the relative contributions of the direct, semidirect, and indirect radiative effects of dust on the dynamics of tropical waves as well as the intensification of vortices in the wake of offshore mesoscale convective systems and their evolution into tropical storms over the North Atlantic. Airborne observations relevant to the assessment of such interactions (active remote sensing, in situ microphysics probes, among others) were made from 8 to 21 September 2021 in the tropical environment of Sal Island, Cape Verde. The environments of several tropical cyclones, including Tropical Storm Rose, were monitored and probed. The airborne measurements also serve the purpose of regional model evaluation and the validation of spaceborne wind, aerosol and cloud products pertaining to satellite missions of the European Space Agency and EUMETSAT (including the Aeolus, EarthCARE, and IASI missions)
Estimating Fatigue Life of Carbon-Epoxy Composites: A Rapid Method coupling Thermo-Mechanical Analysis and Residual Strength
No full textInternational audienceThe investigation of fatigue behavior typically in time-consuming tests, leading some re to explore ologies based on self-heating tests to reduce the process. For composite materials, the conventional ap in piecewise linear approximations of the self-heating curve and the stress transition between the first and second is arbitrarily associated with a fatigue lifetime equal to 106 cycles. This paper proposes a novel ology to address these sim- plifications. First, a non-linear vis tic is used to de the self-heating on the mechanisms estab in the literature, a link is proposed between the dissipation and the fatigue limit. The load leading to a significant con- tribution of non-linear mecha is associated with an infinite life time. It allows the identification of an S-N curve and prediction of fatigue behavior a min- imal number of tests. The comparison with fatigue results is satisfactory