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RISCLESS: A Reinforcement Learning Strategy to Guarantee SLA on Cloud Ephemeral and Stable Resources
No full textInternational audienceIn this paper, we propose RISCLESS, a Reinforcement Learning strategy to exploit unused Cloud resources. Our approach consists in using a small proportion of stable on-demand resources alongside the ephemeral ones in order to guarantee customers SLA and reduce the overall costs. The approach decides when and how much stable resources to allocate in order to fulfill customers’ demands. RISCLESS improved the Cloud Providers (CPs)’ profits by an average of 15.9% compared to past strategies. It also reduced the SLA violation time by 36.7% while increasing the amount of used ephemeral resources by 19.5%
A two-way split-step wavelet method for the 2D tropospheric propagation
No full textInternational audienceModeling the long-range propagation of electromagnetic waves in the troposphere is a topic of interest for many applications in surveillance, communication, and remote-sensing. The split-step Fourier method is widely used in this context, allowing wide steps along the propagation direction. Recently, a wavelet-based method with lower complexity and efficient in terms of memory storage has been proposed. Both methods are one way and compute the forward propagation in the troposphere. Based on the Fourier two-way method, which computes the backward propagation when reaching an obstacle, we propose here a two-way split-step wavelet method. Besides, we show that the stopping criterion is intrinsic using compression in the wavelet domain. Numerical experiments have been performed (in S band) to validate the method and highlight its advantages
What about Sustainability? Investigating Engineering Students' Sustainability Awareness and Attitude
No full textInternational audienceEngineers have a growing contribution towards attaining the Sustainable Development Goals (SDGs). Thus, graduate engineering students' awareness and attitude will be crucial for dealing with these complex societal challenges. The purpose of this study is to investigate the sustainability awareness (SA) of engineering students from a developing country in comparison to that of those published from developed European countries. It also aims to explore engineering students' attitudes and willingness to consider sustainability challenges as an important part of their future professional role. We have conducted a quantitativ
Students' perceptions of applied educational and pedagogical approaches at stem universities: a european overview
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AdaSplats: Adaptive Splatting of Point Clouds for Accurate 3D Modeling and Real-Time High-Fidelity LiDAR Simulation
No full textInternational audienceLiDAR sensors provide rich 3D information about their surroundings and are becoming increasingly important for autonomous vehicles tasks such as localization, semantic segmentation, object detection, and tracking. Simulation accelerates the testing, validation, and deployment of autonomous vehicles while also reducing cost and eliminating the risks of testing in real-world scenarios. We address the problem of high-fidelity LiDAR simulation and present a pipeline that leverages real-world point clouds acquired by mobile mapping systems. Point-based geometry representations, more specifically splats (2D oriented disks with normals), have proven their ability to accurately model the underlying surface in large point clouds, mainly with uniform density. We introduce an adaptive splat generation method that accurately models the underlying 3D geometry to handle real-world point clouds with variable densities, especially for thin structures. Moreover, we introduce a fast LiDAR sensor simulator, working in the splatted model, that leverages the GPU parallel architecture with an acceleration structure while focusing on efficiently handling large point clouds. We test our LiDAR simulation in real-world conditions, showing qualitative and quantitative results compared to basic splatting and meshing techniques, demonstrating the interest of our modeling technique
Tracking baleen whales with a single Ocean bottom seismometer
No full textInternational audienceBaleen whales produce strong and stereotyped songs which are often recorded by Ocean Bottom Seismometers (OBS). As they combine hydroacoustic and seismic sensors, these instruments provide a good opportunity to track the whales from their songs. This study aims at developing a long-range tracking method of baleen whales, based on methods previously developed for ship tracking (Trabattoni 2020). The main goals are:- to accurately estimate the distance of the source using the multipath propagation, and improve the usual detection range;- to estimate the source azimuth using the 3-components seismometer;- to combine the distance and azimuth information to rebuild the whale trajectory
Canonical correlation analysis as a statistical method to relate underwater acoustic propagation and ocean fluctuations
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Modeling Autler-Townes splitting and acoustically induced transparency in a waveguide loaded with resonant channels
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Modélisation semi-analytique du bruit large bande produit par l’interaction entre un écoulement turbulent et un obstacle rigide de forme complexe
No full textInternational audienceL’interaction entre un écoulement turbulent et un obstacle rigide produit un rayonnement acoustique large bande qui peut avoir un impact significatif dans de nombreuses problématiques industrielles. Les méthodes de prédiction existantes ne sont pour la plupart pas adaptées au contexte des applications navales qui impose trois contraintes : les systèmes considérés sont de formes complexes et les écoulements sont généralement à très bas nombre de Mach et à haut Reynolds. Dans ces conditions, les méthodes de calcul directs du bruit qui reposent sur l’utilisation d’une simulation compressible de l’écoulement sont trop coûteuses. D’autres approches doivent être utilisées. Basées sur les analogies acoustiques, elles reposent sur l’idée de séparer les mécanismes de production et les mécanismes de propagation du bruit. Dans cette étude, l’équation d’onde de Lighthill est résolue grâce à une fonction de Green adaptée qui peut être analytique, pour des géométries canoniques, ou déterminée numériquement grâce à la méthode des éléments de frontière. De plus, un modèle pour l’interspectre des fluctuations turbulentes de vitesse, exprimé en espace-fréquence est introduit. Il peut être construit soit à partir d’une estimation des paramètres de couche limite, soit à partir d’une simulation de l’écoulement moyen. Les prédictions obtenues pour le bruit de bord d’attaque et le bruit de bord de fuite sont validées grâce à des mesures effectuées sur un profil NACA 0012, en air