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13,292 results on '"Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut National des Sciences Appliquées (INSA)-Université Toulouse - Jean Jaurès (UT2J)"'

1. Efficient parallelization for 3D-3V sparse grid Particle-In-Cell: Single GPU architectures

Author: Fabrice Deluzet, Gwenael Fubiani, Laurent Garrigues, Clément Guillet, Jacek Narski, Institut de Mathématiques de Toulouse UMR5219 (IMT), Université Toulouse Capitole (UT Capitole), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut National des Sciences Appliquées (INSA)-Université Toulouse - Jean Jaurès (UT2J), Université de Toulouse (UT)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS), Groupe de Recherche Energétique, Plasmas et Hors Equilibre (LAPLACE-GREPHE), LAboratoire PLasma et Conversion d'Energie (LAPLACE), Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT), ANR-19-CE46-0004,MUFFIN,Multiéchelle et Trefftz pour le transport numérique(2019), ANR-11-LABX-0040,CIMI,Centre International de Mathématiques et d'Informatique (de Toulouse)(2011), and Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut National des Sciences Appliquées (INSA)-Université Toulouse - Jean Jaurès (UT2J)-Université Toulouse III - Paul Sabatier (UT3)
Subjects: OpenACC, Hardware and Architecture, sparse grid combination technique, [PHYS.PHYS.PHYS-PLASM-PH]Physics [physics]/Physics [physics]/Plasma Physics [physics.plasm-ph], sparse grids, parallelization, GPU, General Physics and Astronomy, Particle-In-Cell (PIC), [INFO.INFO-DC]Computer Science [cs]/Distributed, Parallel, and Cluster Computing [cs.DC], [MATH.MATH-NA]Mathematics [math]/Numerical Analysis [math.NA], Plasma physics
Abstract: International audience; A. In the present paper, an efficient General Purpose Graphical Processing Unit (GPGPU)-based implementation of sparse grid Particle-In-Cell (PIC) methods is proposed. The parallelization, implementing novel strategies specific to Sparse-PIC methods and tailored to GPU architectures, provides speed-ups* as large as 100 on a single Tesla V100 GPU, with respect to sequential Computing Processing unit (CPU) execution; and a four order of magnitude reduction of the computational time in comparison with a standard PIC sequential CPU simulation. In addition, the simple implementation of the parallelization with the OpenACC framework offers portability to a large class of accelerators.
Published: 2023

2. Hybrid Neural Network -Variational Data Assimilation algorithm to infer river discharges from SWOT-like data

Author: Larnier, Kévin, Monnier, Jerome, CS Group - SI Toulouse [France] (C-S Group), Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT), Institut de Mathématiques de Toulouse UMR5219 (IMT), Université Toulouse Capitole (UT Capitole), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut National des Sciences Appliquées (INSA)-Université Toulouse - Jean Jaurès (UT2J), Université de Toulouse (UT)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS), CNES (N. Picot's project)., and Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut National des Sciences Appliquées (INSA)-Université Toulouse - Jean Jaurès (UT2J)-Université Toulouse III - Paul Sabatier (UT3)
Subjects: inference, neural network, discharge, altimetry, datasets, bathymetry, SWOT mission, Variational data assimilation, [MATH.MATH-OC]Mathematics [math]/Optimization and Control [math.OC], [INFO.INFO-NE]Computer Science [cs]/Neural and Evolutionary Computing [cs.NE], [INFO.INFO-MO]Computer Science [cs]/Modeling and Simulation, [SDE.ES]Environmental Sciences/Environmental and Society, rivers
Abstract: Estimating discharges $Q(x,t)$ from altimetric measurements only, for ungauged rivers (in particular, those with unknown bathymetry b(x)), is an ill-posed inverse problem. We develop here an algorithm to estimate $Q(x,t)$ without prior flow information other than global open datasets. Additionally, the ill-posedness feature of this inverse problem is re-investigated. Inversions based on a Variational Data Assimilation (VDA) approach enable accurate estimation of spatio-temporal variations of the discharge, but with a bias scaling the overall estimate. This key issue, which was already highlighted in our previous studies, is partly solved by considering additional hydrological information (the drainage area, $A\ (km^2)$) combined with a Machine Learning (ML) technique. Purely data-driven estimations obtained from an Artificial Neural Network (ANN) provide a reasonably good estimation at a large scale ($\approx 10^3$ m). This first estimation is then employed to define the first guess of an iterative VDA algorithm. The latter relies on the Saint-Venant flow model and aims to compute the complete unknowns (discharge $Q(x,t)$, bathymetry $b(x)$, friction coefficient $K(x,t)$) at a fine scale (approximately $10^2$ m). The resulting complete inversion algorithm is called the H2iVDI algorithm for "Hybrid Hierarchical Variational Discharge Inference". Numerical experiments have been analyzed for 29 heterogeneous worldwide river portions.The obtained estimations present an overall bias (less than 30\% for rivers with similar characteristics than those used for calibration) smaller than previous results, with accurate spatio-temporal variations of the flow. After a learning period of the observed rivers (e.g. one year), the algorithm provides two complementary estimators: a dynamic flow model enabling estimations at a fine scale and spatio-temporal extrapolations, and a low complexity estimator (based on a dedicated algebraic low Froude flow model).This last estimator provides reasonably accurate estimations (less than 30\% for considered rivers) at a large scale from newly acquired WS measurements in real-time, therefore making it a potentially operational algorithm.
Published: 2023

3. A comparison between Bayesian and ordinary kriging based on validation criteria: application to radiological characterisation

Author: Wieskotten, Martin, Crozet, Marielle, Iooss, Bertrand, Lacaux, Céline, Marrel, Amandine, EA2151 Laboratoire de Mathématiques d'Avignon (LMA), Avignon Université (AU), Institut des Sciences et technologies pour une Economie Circulaire des énergies bas carbone (ISEC), CEA-Direction des Energies (ex-Direction de l'Energie Nucléaire) (CEA-DES (ex-DEN)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Commission des méthodes d'analyse du CEA (CETAMA), Département de recherche sur les procédés pour la mine et le recyclage du combustible (DMRC), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-CEA-Direction des Energies (ex-Direction de l'Energie Nucléaire) (CEA-DES (ex-DEN)), Performance, Risque Industriel, Surveillance pour la Maintenance et l’Exploitation (EDF R&D PRISME), EDF R&D (EDF R&D), EDF (EDF)-EDF (EDF), Méthodes d'Analyse Stochastique des Codes et Traitements Numériques (GdR MASCOT-NUM), Centre National de la Recherche Scientifique (CNRS), Institut de Mathématiques de Toulouse UMR5219 (IMT), Université Toulouse Capitole (UT Capitole), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut National des Sciences Appliquées (INSA)-Université Toulouse - Jean Jaurès (UT2J), Université de Toulouse (UT)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS), Institut de recherche sur les systèmes nucléaires pour la production d'énergie bas carbone (IRESNE), and Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut National des Sciences Appliquées (INSA)-Université Toulouse - Jean Jaurès (UT2J)-Université Toulouse III - Paul Sabatier (UT3)
Subjects: Methodology (stat.ME), FOS: Computer and information sciences, model validation, [MATH.MATH-ST]Mathematics [math]/Statistics [math.ST], FOS: Mathematics, Mathematics - Statistics Theory, kriging, geostatistics, Statistics Theory (math.ST), uncertainty, Statistics - Methodology
Abstract: In decommissioning projects of nuclear facilities, the radiological characterisation step aims to estimate the quantity and spatial distribution of different radionuclides. To carry out the estimation, measurements are performed on site to obtain preliminary information. The usual industrial practice consists in applying spatial interpolation tools (as the ordinary kriging method) on these data to predict the value of interest for the contamination (radionuclide concentration, radioactivity, etc.) at unobserved positions. This paper questions the ordinary kriging tool on the well-known problem of the overoptimistic prediction variances due to not taking into account uncertainties on the estimation of the kriging parameters (variance and range). To overcome this issue, the practical use of the Bayesian kriging method, where the model parameters are considered as random variables, is deepened. The usefulness of Bayesian kriging, whilst comparing its performance to that of ordinary kriging, is demonstrated in the small data context (which is often the case in decommissioning projects). This result is obtained via several numerical tests on different toy models, and using complementary validation criteria: the predictivity coefficient (Q${}^2$), the Predictive Variance Adequacy (PVA), the $\alpha$-Confidence Interval plot (and its associated Mean Squared Error alpha (MSEalpha)), and the Predictive Interval Adequacy (PIA). The latter is a new criterion adapted to the Bayesian kriging results. Finally, the same comparison is performed on a real dataset coming from the decommissioning project of the CEA Marcoule G3 reactor. It illustrates the practical interest of Bayesian kriging in industrial radiological characterisation.
Published: 2023

4. Development of a micro-tissue analysis microsystem by microwave dielectric spectroscopy for the real-time evaluation of biological effects of chemical agents

Author: Olivia Peytral-Rieu, Équipe Micro et nanosystèmes HyperFréquences Fluidiques (LAAS-MH2F), Laboratoire d'analyse et d'architecture des systèmes (LAAS), Université Toulouse Capitole (UT Capitole), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut National des Sciences Appliquées (INSA)-Université Toulouse - Jean Jaurès (UT2J)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Université Toulouse Capitole (UT Capitole), Université de Toulouse (UT), UPS Toulouse, Katia GRENIER, David DUBUC, Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut National des Sciences Appliquées (INSA)-Université Toulouse - Jean Jaurès (UT2J), Université de Toulouse (UT)-Université Toulouse III - Paul Sabatier (UT3), Université Paul Sabatier - Toulouse III, Katia Grenier, and David Dubuc
Subjects: pectroscopie diélectrique microondes, micro-tissues, micro-tissus, drug candidate, Micro-tissue, Microwave dielectric spectroscopy, microcapteur, analyses non invasive, [SPI.ELEC]Engineering Sciences [physics]/Electromagnetism, Drug screening, microsensor, Spectroscopie diélectrique micro-ondes, non-invasive analysis, candidat médicament, dielectric microwave spectroscopy, Drogues, [SPI.NANO]Engineering Sciences [physics]/Micro and nanotechnologies/Microelectronics
Abstract: National audience; Microwave dielectric spectroscopy is a promising analytical technique for many fields of application, especially cell biology. It allows to study cells in their culture medium in a non-invasive and non-destructive way thanks to their dielectric properties. This can be done at various scales, from organ or tissue, from cell suspensions to single cell analysis. In addition, there is an intermediate scale not yet approached with such an analysis technique, that of micro-tissues or spheroids, a highly prized in vitro biological model because it is close to the problems encountered in vivo. These are clusters of cells aggregated together, which present different gradients, both in composition and environment. The cells are in contact with each other and form a sphere, hence the term 3D model or spheroid. The aim of this thesis is to extend the capabilities of cellular analysis by dielectric microwave spectroscopy to this new scale, that of micro-tissues. This work follows a fi! rst demonstrator previously developed in the MH2F research team of LAAS. This first Radiofrequency (RF) microsensor adapted to the microwave measurement of spheroids of 300 µm diameter maintained in their culture medium by an open fluidic system of the reservoir type had been designed, manufactured and started to be evaluated beforehand. In addition to further characterization of this component using multiple models, polystyrene beads and spheroids, to define its measurement capabilities and limitations, an electrical model to obtain the dielectric parameters of the object under study was developed. Thus, after having introduced the spheroids as a biological model and the various existing characterization techniques of this type of model in a first chapter, the second chapter is dedicated to the introduction of this first demonstrator and its analysis capacities. Different solutions were then considered in order to overcome these limitations, including making the fluidic c! onfiguration closed in association with a blocking system of the spheroid to be studied for a precise positioning and thus increase the detection sensitivity. The third chapter of this manuscript presents the corresponding developments, namely the completely redesigned component and the optimization of its manufacturing process. A study of the detection sensitivity according to the dimensioning of the sensor has also been carried out numerically and verified experimentally. The characterization of living spheroids, fixed and also subjected to another chemical agent than paraformaldehyde (used for fixation), chloroquine, allowed to evaluate the potential of the device for a drug screening application. To carry out this study, a collaboration with the company Anti-Oxidant Power was conducted. The detection by RF technique of the impact of the cellular environmental change on spheroids for different concentrations of applied chemical agent thus gives an important proof of conc! ept at the scale of 3D model of the adequacy of this measurement techni! que to observe cellular and even tissue transformations, in complementarity with the traditional optical tools, and this in a non-invasive and non-destructive way and without need for preliminary marking. These results open new analytical perspectives to evaluate the biological response of such 3D models submitted to chemical agents.; La spectroscopie diélectrique micro-onde représente une technique analytique prometteuse pour de nombreux champs applicatifs, biologie cellulaire notamment. Elle permet en effet d'étudier de façon non invasive et non destructive des cellules dans leur milieu de culture grâce à leurs propriétés diélectriques. Ceci peut être réalisé à des échelles variées, que ce soit à l'échelle de l'organe ou du tissu, de suspensions de cellules jusqu'à l'analyse de cellules individuelles. En outre, il existe une échelle intermédiaire non encore abordée avec une telle technique d'analyse, celle des micro-tissus ou encore appelés sphéroïdes, modèle biologique in vitro fortement prisé car se rapprochant des problématiques rencontrées in vivo. Il s'agit d'amas de cellules agrégées entre elles, qui présentent différents gradients, tant en composition qu'environnemental. Les cellules sont en contact les unes aux autres et forment une sphère, d'où le terme de m! odèle 3D ou encore de sphéroïde. Les travaux de thèse visent donc à étendre les capacités d'analyse cellulaire par spectroscopie diélectrique micro-onde à cette nouvelle échelle, celle des micro-tissus.Les travaux réalisés font suite à un premier démonstrateur développé antérieurement dans l'équipe de recherche MH2F du LAAS. Ce premier micro-capteur RadioFréquence (RF) adapté à la mesure micro-onde de sphéroïdes de 300 µm de diamètre maintenu dans leur milieu de culture par un système fluidique ouvert de type réservoir avait été conçu, fabriqué et commencé à être évalué au préalable. Outre une caractérisation plus poussée de ce composant à l'aide de multiples modèles, billes de polystyrène et sphéroïdes, pour en définir les capacités et limitations de mesure, une modélisation électrique permettant d'obtenir les paramètres diélectriques de l'objet étudié a ainsi été développée. Ainsi, après avoir introduit les sphéroïdes comme modèle biologique et les différentes techniques de caractérisation existantes de ce type de modèle dans un premier chapitre, le second chapitre est dédié à l'introduction de ce premier démonstra! teur et de ses capacités d'analyse. Différentes solutions ont alors été envisagées afin de pallier ces limitations, dont le fait de rendre la configuration fluidique fermée en association à un système de blocage du sphéroïde à étudier pour un positionnement précis et donc augmenter la sensibilité de détection. Le troisième chapitre de ce manuscrit présente les développements correspondants, à savoir la conception totalement revue du composant et l'optimisation de son procédé de fabrication. Une étude de sensibilité de détection suivant le dimensionnement du capteur a également été menée numériquement et vérifiée expérimentalement. La caractérisation de sphéroïdes vivants, fixés et aussi soumis à un autre agent chimique que le paraformaldéhyde (utilisé pour la fixation), la chloroquine, a permis d'évaluer le potentiel du dispositif en vue d'une application de type criblage de médicaments. Pour réaliser cette étude, une collaboration! avec l'entreprise Anti-Oxydant Power a été menée. La détection par technique RF de l'impact du changement environnemental cellulaire sur sphéroïdes pour différentes concentrations d'agent chimique appliqué donne ainsi une preuve de concept importante à l'échelle de modèle 3D de l'adéquation de cette technique de mesure pour observer des transformations cellulaires et même tissulaires, en complémentarité aux outils optiques classiques, et ce de façon non invasive et non destructive et sans besoin de marquage préalable. Ces résultats ouvrent donc de nouvelles perspectives d'analyse pour évaluer la réponse biologique de tels modèles tridimensionnels soumis à des agents chimiques.
Published: 2022

5. Pervasive LPWAN connectivity through LEO Satellites: trading off reliability, throughput, latency, and energy efficiency

Author: Zhou, Zheng, Afhamisis, Mohammad, Palattella, Maria Rita, Accettura, Nicola, Berthou, Pascal, Équipe Services et Architectures pour Réseaux Avancés (LAAS-SARA), Laboratoire d'analyse et d'architecture des systèmes (LAAS), Université Toulouse Capitole (UT Capitole), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut National des Sciences Appliquées (INSA)-Université Toulouse - Jean Jaurès (UT2J)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Université Toulouse Capitole (UT Capitole), Université de Toulouse (UT), Luxembourg Institute of Science and Technology (LIST), Ismail Butun, Ian F. Akyildiz, Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut National des Sciences Appliquées (INSA)-Université Toulouse - Jean Jaurès (UT2J), Université de Toulouse (UT)-Université Toulouse III - Paul Sabatier (UT3), and Accettura, Nicola
Subjects: [INFO.INFO-PF]Computer Science [cs]/Performance [cs.PF], [INFO.INFO-NI]Computer Science [cs]/Networking and Internet Architecture [cs.NI], [INFO.INFO-NI] Computer Science [cs]/Networking and Internet Architecture [cs.NI], [INFO.INFO-PF] Computer Science [cs]/Performance [cs.PF], [INFO.INFO-ET] Computer Science [cs]/Emerging Technologies [cs.ET], [INFO.INFO-ET]Computer Science [cs]/Emerging Technologies [cs.ET]
Abstract: To be appear at Springer Book with ID 89136268_Butun and title "Low-Power Wide-Area Networks: Opportunities, Challenges, Risks and Threats" by Ismail Butun and Ian F. Akyildiz; International audience; With the increasing success of the Internet of Things (IoT) industry and the consequent conception of new IoT applications, a significant variety of network design challenges has been unfolded. As a consequence, different Low Power Wide Area Networks (LPWAN) technologies have been developed and marketed to address each specific application need. Among them, the Narrowband IoT (NB-IoT) was developed to target reliable communications over the licensed spectrum, while the Long Range (LoRa) was conceived as a loss-tolerant means over unlicensed frequencies. Recently, satellite LPWAN appeared as a new connectivity option and an affordable solution, particularly suitable for remote and not easily accessible areas. This book chapter timely addresses the opportunities and challenges of such satellite LPWAN architecture by providing a general framework for the evaluation of its performances. The chapter also describes a methodological approach for designing the network, selecting the configuration parameters and the traffic patterns, fitting the best trade-off among reliability, latency, throughput, and energy efficiency.
Published: 2022

6. Source and metric estimation in the eikonal equation using optimization on a manifold

Author: Fehrenbach, Jérôme, Weynans, Lisl, Institut de Mathématiques de Toulouse UMR5219 (IMT), Université Toulouse Capitole (UT Capitole), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut National des Sciences Appliquées (INSA)-Université Toulouse - Jean Jaurès (UT2J), Université de Toulouse (UT)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS), Modélisation et calculs pour l'électrophysiologie cardiaque (CARMEN), Institut de Mathématiques de Bordeaux (IMB), Université Bordeaux Segalen - Bordeaux 2-Université Sciences et Technologies - Bordeaux 1 (UB)-Université de Bordeaux (UB)-Institut Polytechnique de Bordeaux (Bordeaux INP)-Centre National de la Recherche Scientifique (CNRS)-Université Bordeaux Segalen - Bordeaux 2-Université Sciences et Technologies - Bordeaux 1 (UB)-Université de Bordeaux (UB)-Institut Polytechnique de Bordeaux (Bordeaux INP)-Centre National de la Recherche Scientifique (CNRS)-Inria Bordeaux - Sud-Ouest, Institut National de Recherche en Informatique et en Automatique (Inria)-Institut National de Recherche en Informatique et en Automatique (Inria)-IHU-LIRYC, Université Bordeaux Segalen - Bordeaux 2-CHU Bordeaux [Bordeaux]-CHU Bordeaux [Bordeaux], Université Bordeaux Segalen - Bordeaux 2-Université Sciences et Technologies - Bordeaux 1 (UB)-Université de Bordeaux (UB)-Institut Polytechnique de Bordeaux (Bordeaux INP)-Centre National de la Recherche Scientifique (CNRS), Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Université Toulouse 1 Capitole (UT1), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Université Toulouse - Jean Jaurès (UT2J)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS), Université Bordeaux Segalen - Bordeaux 2-Université Sciences et Technologies - Bordeaux 1-Université de Bordeaux (UB)-Institut Polytechnique de Bordeaux (Bordeaux INP)-Centre National de la Recherche Scientifique (CNRS), and Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut National des Sciences Appliquées (INSA)-Université Toulouse - Jean Jaurès (UT2J)-Université Toulouse III - Paul Sabatier (UT3)
Subjects: eikonal equation, Control and Optimization, Modeling and Simulation, Inverse problem, electrocardiographic imaging, Discrete Mathematics and Combinatorics, [MATH.MATH-AP]Mathematics [math]/Analysis of PDEs [math.AP], [MATH.MATH-NA]Mathematics [math]/Numerical Analysis [math.NA], Analysis
Abstract: We address the estimation of the source(s) location in the eikonal equation on a Riemann surface, as well as the determination of the metric when it depends on a few parameters. The available observations are the arrival times or are obtained indirectly from the arrival times by an observation operator, this frame is intended to describe electro-cardiographic imaging. The sensitivity of the arrival times is computed from \begin{document}$ {{{\rm{Log}}}}_x $\end{document} the log map wrt to the source \begin{document}$ x $\end{document} on the surface. The \begin{document}$ {{{\rm{Log}}}}_x $\end{document} map is approximated by solving an elliptic vectorial equation, using the Vector Heat Method. The \begin{document}$ L^2 $\end{document}-error function between the model predictions and the observations is minimized using Gauss-Newton optimization on the Riemann surface. This allows to obtain fast convergence. We present numerical results, where coefficients describing the metric are also recovered like anisotropy and global orientation.
Published: 2021

7. Properties, Extensions and Application of Piecewise Linearization for Euclidean Norm Optimization in R 2

Author: Aloïs Duguet, Christian Artigues, Laurent Houssin, Sandra Ulrich Ngueveu, Équipe Recherche Opérationnelle, Optimisation Combinatoire et Contraintes (LAAS-ROC), Laboratoire d'analyse et d'architecture des systèmes (LAAS), Université Toulouse - Jean Jaurès (UT2J)-Université Toulouse 1 Capitole (UT1), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Université Toulouse - Jean Jaurès (UT2J)-Université Toulouse 1 Capitole (UT1), Université Fédérale Toulouse Midi-Pyrénées, Université Toulouse Capitole (UT Capitole), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut National des Sciences Appliquées (INSA)-Université Toulouse - Jean Jaurès (UT2J)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Université Toulouse Capitole (UT Capitole), Université de Toulouse (UT), Institut Supérieur de l'Aéronautique et de l'Espace (ISAE-SUPAERO), Institut National Polytechnique (Toulouse) (Toulouse INP), Université Toulouse 1 Capitole (UT1), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Université Toulouse - Jean Jaurès (UT2J)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Université Toulouse 1 Capitole (UT1), Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut National des Sciences Appliquées (INSA)-Université Toulouse - Jean Jaurès (UT2J), Université de Toulouse (UT)-Université Toulouse III - Paul Sabatier (UT3), and Duguet, Aloïs
Subjects: Multibeam Satellites, Control and Optimization, [INFO.INFO-RO] Computer Science [cs]/Operations Research [cs.RO], Mixed Integer Linear Programming, Applied Mathematics, Euclidean Norm Linearization, Approximation Guarantee, MathematicsofComputing_NUMERICALANALYSIS, [INFO.INFO-RO]Computer Science [cs]/Operations Research [cs.RO], Management Science and Operations Research, Mixed Integer Nonlinear Programming
Abstract: International audience; This work considers non-convex mixed integer nonlinear programming where nonlinearity comes from the presence of the two-dimensional euclidean norm in the objective or the constraints. We build from the euclidean norm piecewise linearization proposed by Camino et al. [2019], that allows to solve such non-convex problems via mixed-integer linear programming with an arbitrary approximation guarantee. Theoretical results are established that prove that this linearization is able to satisfy any given approximation level with the minimum number of pieces. Anextension of the piecewise linearization approach is proposed. It shares the same theoretical properties for elliptic constraints and/or objective.An application shows the practical appeal of the elliptic linearization on a non-convex beam layout mixed optimization problem coming from an industrial application.
Published: 2021

8. Analytical Bounds for an Interval Kalman Filter

Author: Quoc-Hung Lu, Soheib Fergani, Carine Jauberthie, Équipe DIagnostic, Supervision et COnduite (LAAS-DISCO), Laboratoire d'analyse et d'architecture des systèmes (LAAS), Université Toulouse Capitole (UT Capitole), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut National des Sciences Appliquées (INSA)-Université Toulouse - Jean Jaurès (UT2J), Université de Toulouse (UT)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Université Toulouse Capitole (UT Capitole), and Université de Toulouse (UT)
Subjects: Control and Systems Engineering, Interval Analysis, Interval Kalman Filter, Electrical and Electronic Engineering, Computer Science Applications, [SPI.AUTO]Engineering Sciences [physics]/Automatic
Abstract: International audience; This paper is concerned with analytical developments of results firstly introduced by the authors in [1]. These developments are devoted to the optimization of upper bounds of the interval covariance matrices appearing in the Interval Kalman Filter [2]. The proposed study is mainly highlighted through two aspects. Firstly, the optimization is further performed by considering a class of upper bounds and minimizing the traces of these bounds in two stages (in terms of a gain matrix and then with respect to a scalar parameter). Secondly, the paper provides conditions under which the optimal trace value is controlled and hence the proposed Algorithm in [1], namely Optimal Upper Bound Interval Kalman Filter (OUBIKF), is ensured to perform with stability (i.e. without width explosion of the resulting interval estimators). Also under these conditions, the OUBIKF Algorithm, having a similar structure of the Standard Kalman Filter (SKF), is ensured to get a smaller trace upper bound of the covariance matrices in the correction step than the one in the prediction step. Numerical simulations based on anautomotive model is performed to illustrate the developed results.
Published: 2024

9. Image‐based isogeometric twins of lattices with virtual image correlation for varying cross‐section beams

Author: Jean‐Charles Passieux, Robin Bouclier, Oliver Weeger, Institut Clément Ader (ICA), Institut Supérieur de l'Aéronautique et de l'Espace (ISAE-SUPAERO)-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS)-IMT École nationale supérieure des Mines d'Albi-Carmaux (IMT Mines Albi), Institut Mines-Télécom [Paris] (IMT)-Institut Mines-Télécom [Paris] (IMT), Institut de Mathématiques de Toulouse UMR5219 (IMT), Université Toulouse Capitole (UT Capitole), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut National des Sciences Appliquées (INSA)-Université Toulouse - Jean Jaurès (UT2J), Université de Toulouse (UT)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS), and Technische Universität Darmstadt - Technical University of Darmstadt (TU Darmstadt)
Subjects: Numerical Analysis, isogeometric analysis, lattices, Applied Mathematics, digital twin, General Engineering, cellular materials, image-based models, [SPI.MECA.SOLID]Engineering Sciences [physics]/Mechanics [physics.med-ph]/Solid mechanics [physics.class-ph]
Abstract: International audience; Cellular materials, in particular metal or polymer foams and beam lattices, are characterized by a complex architecture where the material is concentrated in slender struts. This study is concerned with the construction of numerically efficient samplespecific digital twin for the analysis and characterization of the mechanical behavior of such meta-materials. A method to build an explicit, light, and analysis-suitable isogeometric beam model directly from digital images is proposed. More precisely, as a main contribution, the Virtual Image Correlation method is extended to the case of multiple interconnected beams with varying cross-sections. Special care is also given to the initialization for better efficiency and robustness. Synthetic and real examples of increasing complexity, i.e. curved beams, lattices, and foams, are presented to account for the performance of the developed workflow from digital images to an isogeometric twin for mechanical modelling and simulation.
Published: 2024
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10. Nanothermite based anti-tamping technology

Author: Sevely, Florent, Assié-Souleille, Sandrine, Salvagnac, Ludovic, Estève, Alain, Rossi, Carole, Équipe Nano-ingénierie et intégration des oxydes métalliques et de leurs interfaces (LAAS-NEO), Laboratoire d'analyse et d'architecture des systèmes (LAAS), Université Toulouse Capitole (UT Capitole), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut National des Sciences Appliquées (INSA)-Université Toulouse - Jean Jaurès (UT2J), Université de Toulouse (UT)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Université Toulouse Capitole (UT Capitole), Université de Toulouse (UT), Service Instrumentation Conception Caractérisation (LAAS-I2C), and Material Research Society
Subjects: [SPI]Engineering Sciences [physics], [SPI.MAT]Engineering Sciences [physics]/Materials
Abstract: International audience; We developed a triggerable ultimate security device capable of physically destroying a memory chip that contains classified data, within a few milliseconds, upon the detection of intrusion.
Published: 2023

11. A controversial study on Random Forest Accuracy for Attack Detection

Author: Vacher, Quentin, Owezarski, Philippe, Équipe Services et Architectures pour Réseaux Avancés (LAAS-SARA), Laboratoire d'analyse et d'architecture des systèmes (LAAS), Université Toulouse Capitole (UT Capitole), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut National des Sciences Appliquées (INSA)-Université Toulouse - Jean Jaurès (UT2J), Université de Toulouse (UT)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Université Toulouse Capitole (UT Capitole), Université de Toulouse (UT), Science and Information organization (SAI), and Springer
Subjects: Random Forest, training, Attack detection, Machine learning, [INFO]Computer Science [cs], controversial thoughts, adversarial learning, Attack detection Machine learning Random Forest adversarial learning training controversial thoughts
Abstract: International audience; Machine learning based anomaly and attack detection is a topic under the spotlights for more than one decade. It is raising a significant research effort worldwide. The reasons of this interest lie in the ability of machine learning to introduce a large part of autonomy in the attacks detection process compared to the classical signature based approach, and then reduces the management cost of networks for NetOps, provides rapid and efficient results, and is prone to detect 0d attacks. This paper confirms this efficiency showing that using the simple Random Forest (RF) algorithms together with features selection allows detection ratio greater than 99%. However, despite a large set of attempts on the training stage for improving this detection ratio, RF never detects 100% of attacks. It especially always misses some attacks in the traffic, especially under-represented ones in the training dataset. False Negatives are certainly the most dramatic events for network security. In addition, it makes adversarial learning very easy to perform. This paper then presents a controversial study on machine learning based attack detection (using the significantly illustrative RF example), and its trustworthiness limits. This paper is then trying to break the current dogma that machine learning is THE solution for future cyber-security systems.
Published: 2023

12. Minimizing bacterial adhesion on membrane: Multiscale characterization of surface modifications

Author: Abigail Burato Rosales, Nadège Durban-Benizio, Xuan Loc Nguyen, Vincent Bouvier, Clémentine Lamo, Irem Demir-Yilmaz, Christel Causserand, Cécile Formosa-Dague, Clémence Coetsier, Laboratoire de Génie Chimique (LGC), Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT), Toulouse Biotechnology Institute (TBI), Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE), Laboratoire d'analyse et d'architecture des systèmes (LAAS), Université Toulouse Capitole (UT Capitole), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut National des Sciences Appliquées (INSA)-Université Toulouse - Jean Jaurès (UT2J), Université de Toulouse (UT)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), ANR-17-CE04-0001,BIOCOM,Modification de Membranes pour le COntrôle du BIO-colmatage(2017), and ANR-18-CE43-0101,FLOTALG,Biophysique de la flottation des microalgues
Subjects: Anti-biofouling, Interfacial characterization, Atomic force microscopy, Surface modification, [CHIM.GENI]Chemical Sciences/Chemical engineering, [CHIM.POLY]Chemical Sciences/Polymers, Microfiltration
Abstract: International audience; The control of biofouling is required to improve membranes performances for water filtration. In this context, developing bioinspired approaches to modify membranes and give them antifouling properties is an interesting alternative. In this study, we elaborated new anti-biofouling membranes by coating them with vanillin, a natural bioactive molecule acting as a Quorum Sensing Inhibitor (QSI). First, the adsorption of vanillin by filtration was optimized to obtain homogeneous surface modifications. The modified membranes were then characterized in terms of physical-chemical properties: the results showed that they were more hydrophobic and exhibited a 14% decrease in pure water flux. Then, their anti-fouling properties were evaluated using complementary multiscale characterization methodologies; AFM single-cell experiments showed that vanillin adsorption had an effect on both the probability of bacterial cells to adhere to the surface, and on the force of adhesion. Direct EFM and SEM observation and adhesion assays further confirmed the effect of vanillin-modified membranes at the population-scale which showed a decrease in the bacterial coverage rate up to 50%. Altogether, it confirms the multifunctionality of vanillin-coated membranes against biofouling: reduction of bacterial initial adhesion by changing the membranes surface properties and reduction of biofilm formation by quorum sensing inhibition
Published: 2023

13. RF sensor dedicated to the dielectric characterization of spheroids between 500 MHz and 20 GHz

Author: Olivia Peytral-Rieu, David Dubuc, Katia Grenier, Équipe Micro et nanosystèmes HyperFréquences Fluidiques (LAAS-MH2F), Laboratoire d'analyse et d'architecture des systèmes (LAAS), Université Toulouse Capitole (UT Capitole), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut National des Sciences Appliquées (INSA)-Université Toulouse - Jean Jaurès (UT2J), Université de Toulouse (UT)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Université Toulouse Capitole (UT Capitole), and Université de Toulouse (UT)
Subjects: Coplanar waveguide (CPW), Label-free analysis, [PHYS]Physics [physics], Electromagnetic waves, Cells, [SDV]Life Sciences [q-bio], Dielectric characterization, Spheroids, Electrical and Electronic Engineering, Microwave, Biosensor, Biosensor Microwave Electromagnetic waves Dielectric characterization Coplanar waveguide (CPW) Label-free analysis Spheroids Cells
Abstract: To achieve better accuracy in their investigations, biologists have recently been using three-dimensional models as intermediates between two-dimensional cell culture and the in vivo study of tissues. Some of these models are based on spheroids, which are cellular aggregates retaining many characteristics of in vivo behaviors while being still easy to use and implement in labs. To study such objects, multiple observation techniques can be used according to the objective of the study, including those using electromagnetic waves as nondestructive, noninvasive, and label-free analysis. Low-frequency (
Published: 2023

14. Solving Nonlinear Algebraic Loops Arising in Input-Saturated Feedbacks

Author: Franco Blanchini, Giulia Giordano, Francesco Riz, Luca Zaccarian, Dipartimento di Ingegneria Industriale [Trento], University of Trento [Trento], Équipe Méthodes et Algorithmes en Commande (LAAS-MAC), Laboratoire d'analyse et d'architecture des systèmes (LAAS), Université Toulouse Capitole (UT Capitole), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut National des Sciences Appliquées (INSA)-Université Toulouse - Jean Jaurès (UT2J), Université de Toulouse (UT)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Université Toulouse Capitole (UT Capitole), Université de Toulouse (UT), and ANR-18-CE40-0010,HANDY,Systèmes Dynamiques Hybrides et en Réseau(2018)
Subjects: [SPI]Engineering Sciences [physics], Iterative methods, Control and Systems Engineering, Linear matrix inequalities, Heuristic algorithms, Software packages, Approximation algorithms, Simulation, Tuning, Electrical and Electronic Engineering, Computer Science Applications
Abstract: We propose a dynamic augmentation scheme for the asymptotic solution of the nonlinear algebraic loops arising in well-known input saturated feedbacks typically designed by solving linear matrix inequalities (LMIs). We prove that the existing approach based on dynamic augmentation, which replaces the static loop by a dynamic one through the introduction of a sufficiently small time constant, works under some restrictive sufficient well-posedness conditions, requiring the existence of a diagonal Lyapunov matrix. However it can fail in general, even when the algebraic loop is well-posed. Then, we propose a novel approach whose effectiveness is guaranteed whenever wellposedness holds. We also show how this augmentation allows preserving the guaranteed region of attraction with Lyapunovbased designs, as long as a gain parameter is sufficiently large. We finally propose an adaptive version of the scheme where this parameter is adjusted online. Simulation results show the effectiveness of the proposed solutions.
Published: 2023

15. Toward an Operations-Dedicated Model for Space Systems

Author: Nikolena Christofi, Xavier Pucel, Claude Baron, Marc Pantel, Sebastien Guilmeau, Christophe Ducamp, Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT), IRT Saint Exupéry - Institut de Recherche Technologique, Équipe Ingénierie Système et Intégration (LAAS-ISI), Laboratoire d'analyse et d'architecture des systèmes (LAAS), Université Toulouse Capitole (UT Capitole), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut National des Sciences Appliquées (INSA)-Université Toulouse - Jean Jaurès (UT2J), Université de Toulouse (UT)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Université Toulouse Capitole (UT Capitole), Université de Toulouse (UT), ONERA / DTIS, Université de Toulouse [Toulouse], ONERA-PRES Université de Toulouse, Assistance à la Certification d’Applications DIstribuées et Embarquées (IRIT-ACADIE), Institut de recherche en informatique de Toulouse (IRIT), Université de Toulouse (UT)-Université de Toulouse (UT)-Université Toulouse - Jean Jaurès (UT2J), Université de Toulouse (UT)-Toulouse Mind & Brain Institut (TMBI), Université Toulouse - Jean Jaurès (UT2J), Université de Toulouse (UT)-Université de Toulouse (UT)-Université Toulouse III - Paul Sabatier (UT3), and Airbus Defence and Space [Toulouse]
Subjects: Aerospace Engineering, [INFO.INFO-ES]Computer Science [cs]/Embedded Systems, Electrical and Electronic Engineering, Computer Science Applications
Abstract: International audience; Current trends in the aerospace industry for the digitization of data, tools, and services call for novel solutions that can keep track of the latest technological advancements. Moreover, the increasing drive toward model-based approaches imposes the use of models for the development of complex systems, such as satellites. New types of methods and tools are needed in order to manage the still-growing complexity of embedded systems and their corresponding models. This paper addresses issues related to space systems (in-service) operations and proposes a multimodel approach to address them. The multimodel approach aims at facilitating the task of operational diagnosis by creating a monitoring and diagnosis-dedicated system model derived from existing system design (architecture, functional behavior, and safety) models. The purpose of the diagnosis-dedicated model is to enable the codesign of the system and its diagnosis tools in order to improve the performance of diagnosis activities and the system’s availability. This paper demonstrates the interests of the suggested approach with regard to the limitations of current practices.
Published: 2023

16. The structure of pathogenic huntingtin exon 1 defines the bases of its aggregation propensity

Author: Carlos A. Elena-Real, Amin Sagar, Annika Urbanek, Matija Popovic, Anna Morató, Alejandro Estaña, Aurélie Fournet, Christine Doucet, Xamuel L. Lund, Zhen-Dan Shi, Luca Costa, Aurélien Thureau, Frédéric Allemand, Rolf E. Swenson, Pierre-Emmanuel Milhiet, Ramon Crehuet, Alessandro Barducci, Juan Cortés, Davy Sinnaeve, Nathalie Sibille, Pau Bernadó, Centre de Biologie Structurale [Montpellier] (CBS), Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Université de Montpellier (UM), Équipe Robotique et InteractionS (LAAS-RIS), Laboratoire d'analyse et d'architecture des systèmes (LAAS), Université Toulouse Capitole (UT Capitole), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut National des Sciences Appliquées (INSA)-Université Toulouse - Jean Jaurès (UT2J), Université de Toulouse (UT)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Université Toulouse Capitole (UT Capitole), Université de Toulouse (UT), Institut Laue-Langevin (ILL), National Institutes of Health [Bethesda] (NIH), Beamline SWING, Synchrotron SOLEIL, Synchrotron SOLEIL (SSOLEIL), Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), Institute for Advanced Chemistry of Catalonia (IQAC-CSIC), Institute for Advanced Chemistry of Catalonia, Biologie Structurale Intégrative (ERL 9002 - BSI ), Institut Pasteur de Lille, Réseau International des Instituts Pasteur (RIIP)-Réseau International des Instituts Pasteur (RIIP)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Université de Lille-Centre National de la Recherche Scientifique (CNRS), Facteurs de Risque et Déterminants Moléculaires des Maladies liées au Vieillissement - U 1167 (RID-AGE), Réseau International des Instituts Pasteur (RIIP)-Réseau International des Instituts Pasteur (RIIP)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Université de Lille-Centre Hospitalier Régional Universitaire [Lille] (CHRU Lille), ANR-10-LABX-0012,EpiGenMed,From Genome and Epigenome to Molecular Medicine: turning new paradigms in biology into the therapeutic strategies of tomorrow(2010), ANR-17-CE11-0022,GPCteR,Mécanismes moléculaires des régions C-terminales désordonnées et fonctionnelles des RCPG et impact sur les voies de la signalisation cellulaire dépendantes de l'arrestine(2017), ANR-19-P3IA-0004,ANITI,Artificial and Natural Intelligence Toulouse Institute(2019), European Project: 648030,H2020,ERC-2014-CoG,chemREPEAT(2015), and European Commission
Subjects: Huntington’s disease is a neurodegenerative disorder, poly-Q-related diseases, Pathogenic huntingtin, Structural Biology, [SDV]Life Sciences [q-bio], Proteins, Protein aggregation, [INFO.INFO-BI]Computer Science [cs]/Bioinformatics [q-bio.QM], HTT gene, Solution-state NMR, Molecular Biology
Abstract: Huntington's disease is a neurodegenerative disorder caused by a CAG expansion in the first exon of the HTT gene, resulting in an extended polyglutamine (poly-Q) tract in huntingtin (httex1). The structural changes occurring to the poly-Q when increasing its length remain poorly understood due to its intrinsic flexibility and the strong compositional bias. The systematic application of site-specific isotopic labeling has enabled residue-specific NMR investigations of the poly-Q tract of pathogenic httex1 variants with 46 and 66 consecutive glutamines. Integrative data analysis reveals that the poly-Q tract adopts long α-helical conformations propagated and stabilized by glutamine side chain to backbone hydrogen bonds. We show that α-helical stability is a stronger signature in defining aggregation kinetics and the structure of the resulting fibrils than the number of glutamines. Our observations provide a structural perspective of the pathogenicity of expanded httex1 and pave the way to a deeper understanding of poly-Q-related diseases., We thank G. Otting (Australian National University, Canberra, Australia) for providing the BL21 (DE3) Star::RF1-CBD3 strain. This work was supported by the European Research Council under the European Union’s H2020 Framework Programme (2014–2020)/ERC grant agreement no. 648030 and Labex EpiGenMed, an Investissements d’avenir program (grant no. ANR-10-LABX-12-01) awarded to P.B., grant no. ANR-17-CE11-0022-01 awarded to N.S. and grant no. ANR-19-PI3A-0004 awarded to J.C. The Centre for Structural Biology (CBS) is a member of France-BioImaging (FBI) and the French Infrastructure for Integrated Structural Biology, two national infrastructures supported by the French National Research Agency (grant nos. ANR-10-INBS-04-01 and ANR-10-INBS-05, respectively). A.U. is supported by a grant from the Fondation pour la Recherche Médicale (grant no. SPF20150934061). D.S. acknowledges a grant from the Métropole Européenne de Lille (PUSHUP). G. Levy (Université de Lille) is thanked for help with sample preparation and the 19F-NMR experiments. This work benefited from the high-performance computing resources of CSUC and the CALMIP supercomputing center under the allocations 2016-P16032 and 2021-P21043. The 600 MHz spectrometer for 19F-NMR measurements is funded by the Nord Region Council, CNRS, Institut Pasteur de Lille, the European Community (European Regional Development Fund, ERDF), the French Ministry of Research and the Université de Lille and by the CTRL CPER cofunded by the European Union with the ERDF, by the Hauts-de-France Regional Council (contract no. 17003781), Métropole Européenne de Lille (contract no. 2016_ESR_05) and the French State (contract no .2017-R3-CTRL-Phase1). We thank the SWING beamline at the SOLEIL synchrotron, Saint-Aubin, France (proposal 20181386), and P12 beamline at PETRAIII, Hamburg, Germany, for beamtime allocation to the project and assistance during data collection.
Published: 2023

17. Hybrid Control of Self-Oscillating Resonant Converters

Author: Nicola Zaupa, Luis Martínez-Salamero, Carlos Olalla, Luca Zaccarian, Équipe Méthodes et Algorithmes en Commande (LAAS-MAC), Laboratoire d'analyse et d'architecture des systèmes (LAAS), Université Toulouse Capitole (UT Capitole), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut National des Sciences Appliquées (INSA)-Université Toulouse - Jean Jaurès (UT2J), Université de Toulouse (UT)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Université Toulouse Capitole (UT Capitole), Université de Toulouse (UT), Université Toulouse III - Paul Sabatier (UT3), Universitat Rovira i Virgili, Dipartimento di Ingegneria Industriale [Trento], University of Trento [Trento], Spanish Ministry of Science and Innovation (Grant Number: PID2019-111443RB-100), International Exchange Program of the University of Trento, Italy, ANR-18-CE40-0010,HANDY,Systèmes Dynamiques Hybrides et en Réseau(2018), ZAUPA, Nicola, and Systèmes Dynamiques Hybrides et en Réseau - - HANDY2018 - ANR-18-CE40-0010 - AAPG2018 - VALID
Subjects: [SPI.AUTO] Engineering Sciences [physics]/Automatic, Control and Systems Engineering, Power electronics, [SPI.NRJ]Engineering Sciences [physics]/Electric power, Electrical and Electronic Engineering, Stability of hybrid systems, Resonant converters, Power conversion, Lyapunov methods, [SPI.AUTO]Engineering Sciences [physics]/Automatic
Abstract: International audience; We describe parallel and series resonant converters via a unified set of input-dependent coordinates whose dynamics is intrinsically hybrid. We then propose a hybrid feedback showing a self-oscillating behavior whose amplitude and frequency can be adjusted by a reference input ranging from zero to π. For any reference value in that range we give a Lyapunov function certifying the existence of a unique nontrivial hybrid limit cycle whose basin of attraction is global except for the origin. Our results are confirmed by experimental results on a series resonant converter prototype.
Published: 2023

18. Overworld: Assessing the Geometry of the World for Human-Robot Interaction

Author: Guillaume Sarthou, Équipe Robotique et InteractionS (LAAS-RIS), Laboratoire d'analyse et d'architecture des systèmes (LAAS), Université Toulouse Capitole (UT Capitole), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut National des Sciences Appliquées (INSA)-Université Toulouse - Jean Jaurès (UT2J), Université de Toulouse (UT)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Université Toulouse Capitole (UT Capitole), and Université de Toulouse (UT)
Subjects: Human-Computer Interaction, Human-Robot Collaboration, Control and Optimization, Multi-Modal Perception for HRI, Artificial Intelligence, Control and Systems Engineering, Mechanical Engineering, Biomedical Engineering, Software Architecture for Robotic and Automation, [INFO]Computer Science [cs], Computer Vision and Pattern Recognition, Computer Science Applications
Abstract: International audience; For a robot to interact with humans in a given environment, a key need is to understand its environment in terms of the objects composing it, the other agents acting in it, and the relations between all of them. This capability is often called the geometrical situation assessment and is mainly related to spatial reasoning in time. In this paper, we present Overworld, a novel lightweight and open-source framework, merging the key features of a decade of research in the domain. It permanently maintains a geometric state of the world from the point of view of the robot by aggregating perceptual information from several sources and reasoning on them to create a coherent world. Furthermore, Overworld implements perspective-taking by emulating the humans' ability to perceive to estimate the state of the world from their perspective. Finally, thanks to a strong link with an ontology framework, it ensures knowledge coherence in the whole robotic architecture. This work is part of a broader effort to develop a complete, stable, and shareable decisional robotic architecture for Human-Robot Interaction.
Published: 2023

19. SONC optimization and exact nonnegativity certificates via second-order cone programming

Author: Magron, Victor, Wang, Jie, Institut de Mathématiques de Toulouse UMR5219 (IMT), Université Toulouse Capitole (UT Capitole), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut National des Sciences Appliquées (INSA)-Université Toulouse - Jean Jaurès (UT2J), Université de Toulouse (UT)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS), Équipe Méthodes et Algorithmes en Commande (LAAS-MAC), Laboratoire d'analyse et d'architecture des systèmes (LAAS), Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Université Toulouse Capitole (UT Capitole), Université de Toulouse (UT), ANR-18-ERC2-0004,COPS,Optimisation garantie pour la vérification des systèmes cyber-physiques(2018), ANR-19-P3IA-0004,ANITI,Artificial and Natural Intelligence Toulouse Institute(2019), European Project: 813211,H2020-EU.1.3. - EXCELLENT SCIENCE - Marie Skłodowska-Curie Actions (Main Programme), H2020-EU.1.3.1. - Fostering new skills by means of excellent initial training of researchers ,10.3030/813211,POEMA(2019), Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Université Toulouse 1 Capitole (UT1), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Université Toulouse - Jean Jaurès (UT2J)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS), Université Toulouse - Jean Jaurès (UT2J)-Université Toulouse 1 Capitole (UT1), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Université Toulouse - Jean Jaurès (UT2J)-Université Toulouse 1 Capitole (UT1), Université Fédérale Toulouse Midi-Pyrénées, and European Project: 813211,H2020,POEMA(2019)
Subjects: FOS: Computer and information sciences, Computer Science - Symbolic Computation, Algebra and Number Theory, MathematicsofComputing_NUMERICALANALYSIS, Symbolic Computation (cs.SC), sum of binomial squares, exact nonnegativity certificate, Mathematics - Algebraic Geometry, Computational Mathematics, rounding-projection algorithm, Optimization and Control (math.OC), sum of nonnegative circuit polynomials, second-order cone programming, polynomial optimization, ComputingMethodologies_SYMBOLICANDALGEBRAICMANIPULATION, FOS: Mathematics, second-order conerepresentation, [MATH.MATH-OC]Mathematics [math]/Optimization and Control [math.OC], Algebraic Geometry (math.AG), Mathematics - Optimization and Control
Abstract: The second-order cone (SOC) is a class of simple convex cones and optimizing over them can be done more efficiently than with semidefinite programming. It is interesting both in theory and in practice to investigate which convex cones admit a representation using SOCs, given that they have a strong expressive ability. In this paper, we prove constructively that the cone of sums of nonnegative circuits (SONC) admits a SOC representation. Based on this, we give a new algorithm for unconstrained polynomial optimization via SOC programming. We also provide a hybrid numeric-symbolic scheme which combines the numerical procedure with a rounding-projection algorithm to obtain exact nonnegativity certificates. Numerical experiments demonstrate the efficiency of our algorithm for polynomials with fairly large degree and number of variables., 29 pages, 7 tables, 6 figures, extended version of the article published in the proceedings of ISSAC 2020. arXiv admin note: text overlap with arXiv:1906.06179
Published: 2023

20. Value-Added Trade, Trade Barriers, and International Technology Spillover—Evidence from China’s Manufacturing Industry

Author: Qiao, Xiaoyong, Li, Xingyao, Ling, Xin, Xue, Rui, Baron, Claude, Xin, Xiaoxuan, Beijing University of Technology, Équipe Ingénierie Système et Intégration (LAAS-ISI), Laboratoire d'analyse et d'architecture des systèmes (LAAS), Université Toulouse Capitole (UT Capitole), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut National des Sciences Appliquées (INSA)-Université Toulouse - Jean Jaurès (UT2J), Université de Toulouse (UT)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Université Toulouse Capitole (UT Capitole), Université de Toulouse (UT), and This work was financially supported by theNational Natural Science Foundation of China (71774008)
Subjects: Global value chains, International technology spillover, Value-added trade, [INFO]Computer Science [cs], Trade barriers, Manufacturing industry
Abstract: International audience; Abstract Whereas the technology spillover effect of international trade has been widely concerned by academic circles, the impact of trade barriers on technology spillover has received relatively less attention. This paper assesses the heterogeneity of international technology spillover effects in China’s manufacturing industry from traditional gross trade and value-added trade perspectives. Moreover, a deep insight into the effects of tariff and non-tariff barriers on international technology diffusion from traditional gross trade and value-added trade perspectives is also provided. Results show that the international trade indeed engenders technology diffusion, which is especially true in value-added trade characterized by intermediate goods trade compared with traditional gross trade. Additionally, tariff barriers severely disrupt technology diffusion in international trade, and traditional gross trade statistics underestimate the cumulative destructive effect of trade barriers on technology diffusion. Consequently, it can be concluded that reducing the abuse and misuse of non-tariff barriers can moderate the negative effect of trade barriers on international technology diffusion. JEL classification numbers: F14. Keywords: Global value chains; Value-added trade; Trade barriers; International technology spillover; Manufacturing industry.
Published: 2023

21. Force Sharing Problem During Gait Using Inverse Optimal Control

Author: Filip Becanovic, Vincent Bonnet, Raphael Dumas, Kosta Jovanovic, Samer Mohammed, School of Electrical Engineering (ETF), University of Belgrade [Belgrade], Laboratoire d'analyse et d'architecture des systèmes (LAAS), Université Toulouse Capitole (UT Capitole), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut National des Sciences Appliquées (INSA)-Université Toulouse - Jean Jaurès (UT2J), Université de Toulouse (UT)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT), Laboratoire de Biomécanique et Mécanique des Chocs (LBMC UMR T9406 ), Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Université Gustave Eiffel, Université Paris Est Créteil, parent, and Amirat, Yacine
Subjects: Control and Optimization, OPTIMISATION, Mechanical Engineering, [INFO.INFO-RB] Computer Science [cs]/Robotics [cs.RO], FACTEUR HUMAIN, HUMAN-IN-THE-LOOP, Biomedical Engineering, CONTROLE OPTIMAL, [SPI.MECA.BIOM]Engineering Sciences [physics]/Mechanics [physics.med-ph]/Biomechanics [physics.med-ph], Computer Science Applications, Human-Computer Interaction, Artificial Intelligence, Control and Systems Engineering, MODELING AND SIMULATING HUMANS, Computer Vision and Pattern Recognition
Abstract: International audience; Human gait patterns have been intensively studied, both from medical and engineering perspectives, to understand and compensate pathologies. However, the muscle-force sharing problem is still debated as acquiring individual muscle force measurements is challenging, requiring the use of invasive devices.Recent studies, using various objective functions, suggest muscleforce sharing may result from an optimization process. This study proposes using inverse optimal control to identify an objective function. Two popular methods of inverse optimal control, bilevel and inverse Karush-Kuhn-Tucker, were investigated. The identifiedobjective functions were then used to predict muscle forces during gait, and their performances were compared to an exhaustive list of biological cost functions from the literature. The best predictionwas achieved by the bilevel inverse optimal control method, with a root-mean-squared error of 176 N (162 N) and a correlationcoefficient of 0.76 (0.68) for the stance (swing) phase of the gait cycle.These muscle force predictions were thereafter used to compute joint stiffness, exhibiting an average root-mean-square error of 42 Nm.rad?1 and a correlation coefficient of 0.90 when comparedto the reference. The bilevel method's prevalence in terms of robustnessover inverse Karush-Kuhn-Tucker was demonstrated on human data and explained on a toy example.
Published: 2023

22. Data-driven stabilization of input-saturated systems

Author: Valentina Breschi, Luca Zaccarian, Simone Formentin, Control Systems, Eindhoven University of Technology [Eindhoven] (TU/e), Dipartimento di Ingegneria Industriale [Trento], University of Trento [Trento], Équipe Méthodes et Algorithmes en Commande (LAAS-MAC), Laboratoire d'analyse et d'architecture des systèmes (LAAS), Université Toulouse Capitole (UT Capitole), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut National des Sciences Appliquées (INSA)-Université Toulouse - Jean Jaurès (UT2J), Université de Toulouse (UT)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Université Toulouse Capitole (UT Capitole), Université de Toulouse (UT), Dipartimento di Electtronica, Informazione e Bioingegneria [Politecnico Milano] (POLIMI), Politecnico di Milano [Milan] (POLIMI), and ANR-18-CE40-0010,HANDY,Systèmes Dynamiques Hybrides et en Réseau(2018)
Subjects: [SPI]Engineering Sciences [physics], Control and Optimization, Data-driven control, Control and Systems Engineering, input saturation, Linear systems, State feedback, Lyapunov methods
Abstract: International audience; We provide a data-driven stabilization approach for input-saturated systems with formal Lyapunov guarantees. Through a generalized sector condition, we propose a convex design algorithm based on linear matrix inequalities for obtaining a regionally stabilizing datadriven static state-feedback gain. Regional, rather than global, properties allow us to address non-exponentially stable plants, thereby making our design broad in terms of applicability. Moreover, we discuss consistency issues and introduce practical tools to deal with measurement noise. Numerical simulations show the effectiveness of our approach and its sensitivity to the features of the dataset.
Published: 2023

23. Existence and Completeness of Solutions to Extended Projected Dynamical Systems and Sector-Bounded Projection-Based Controllers

Author: W. P. M. H. Heemels, Aneel Tanwani, Eindhoven University of Technology [Eindhoven] (TU/e), Équipe Méthodes et Algorithmes en Commande (LAAS-MAC), Laboratoire d'analyse et d'architecture des systèmes (LAAS), Université Toulouse Capitole (UT Capitole), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut National des Sciences Appliquées (INSA)-Université Toulouse - Jean Jaurès (UT2J), Université de Toulouse (UT)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Université Toulouse Capitole (UT Capitole), and Université de Toulouse (UT)
Subjects: Nonsmooth dynamics, Control and Optimization, Control and Systems Engineering, [INFO.INFO-SY]Computer Science [cs]/Systems and Control [cs.SY], [MATH.MATH-OC]Mathematics [math]/Optimization and Control [math.OC], Projection based control
Abstract: Projection-based control (PBC) systems have significant engineering impact and receive considerable scientific attention. To properly describe closed-loop PBC systems, extensions of classical projected dynamical systems are needed, because partial projection operators and irregular constraint sets (sectors) are crucial in PBC. These two features obstruct the application of existing results on existence and completeness of solutions. To establish a rigorous foundation for the analysis and design of PBC, we provide essential existence and completeness properties for this new class of discontinuous systems.
Published: 2023

24. Stabilization using shifted equilibria for saturated discrete-time linear systems⋆

Author: Braun, Philipp, Jungers, Marc, Zaccarian, Luca, Jungers, Marc, Australian National University (ANU), Centre de Recherche en Automatique de Nancy (CRAN), Université de Lorraine (UL)-Centre National de la Recherche Scientifique (CNRS), Équipe Méthodes et Algorithmes en Commande (LAAS-MAC), Laboratoire d'analyse et d'architecture des systèmes (LAAS), Université Toulouse Capitole (UT Capitole), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut National des Sciences Appliquées (INSA)-Université Toulouse - Jean Jaurès (UT2J), Université de Toulouse (UT)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Université Toulouse Capitole (UT Capitole), Université de Toulouse (UT), and ANR-18-CE40-0010,HANDY,Systèmes Dynamiques Hybrides et en Réseau(2018)
Subjects: [SPI.AUTO] Engineering Sciences [physics]/Automatic, Systems with saturation, Asymptotic stabilization, Control and Systems Engineering, discrete-time systems, semidefinite programming, [SPI.AUTO]Engineering Sciences [physics]/Automatic, Lyapunov methods
Abstract: International audience; We discuss controller designs for asymmetric saturated discrete-time linear systems. Under the assumption that a locally stabilizing controller of the origin is known, we augment the original controller with an additional term that vanishes in a neighborhood of the origin. The augmented controller outperforms the original controller in terms of the estimate of the region of attraction. The paper translates the results discussed in Braun et al. (2022a,b), from the continuous-time setting to the discrete-time setting, and numerically verifies that the results derived for continuous-time systems are recovered if the discrete-time system is obtained through an Euler discretization of a continuous-time system with a sufficiently small sampling rate.
Published: 2023

25. Analyticity of the semigroup corresponding to a strongly damped wave equation with a Ventcel boundary condition

Author: Badra, Mehdi, Takahashi, Takéo, Institut de Mathématiques de Toulouse UMR5219 (IMT), Université Toulouse Capitole (UT Capitole), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut National des Sciences Appliquées (INSA)-Université Toulouse - Jean Jaurès (UT2J), Université de Toulouse (UT)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS), Institut Élie Cartan de Lorraine (IECL), Université de Lorraine (UL)-Centre National de la Recherche Scientifique (CNRS), Systems with physical heterogeneities : inverse problems, numerical simulation, control and stabilization (SPHINX), Inria Nancy - Grand Est, Institut National de Recherche en Informatique et en Automatique (Inria)-Institut National de Recherche en Informatique et en Automatique (Inria), and ANR-20-CE40-0009,TRECOS,Nouvelles directions en contrôle et stabilisation: Contraintes et termes non-locaux(2020)
Subjects: Applied Mathematics, analytic semigroups, [MATH.MATH-AP]Mathematics [math]/Analysis of PDEs [math.AP], Ventcel boundary condition, structurally damped wave equation, Analysis, 2020 Mathematics Subject Classification. 35B65, 35L05, 35K90
Abstract: International audience; We consider a wave equation with a structural damping coupled with an undamped wave equation located at its boundary. We prove that, due to the coupling, the full system is parabolic. In order to show that the underlying operator generates an analytical semigroup, we study in particular the effect of the damping of the "interior" wave equation on the "boundary" wave equation and show that it generates a structural damping.
Published: 2023

26. Robust Global Asymptotic Stabilization of Linear Cascaded Systems With Hysteretic Interconnection

Author: Alessandro Bosso, Luca Zaccarian, Andrea Tilli, Matteo Barbieri, Department of electrical, electronic and information engineering 'GUGLIELMO MARCONI' [Bologna] (DEI), Alma Mater Studiorum Università di Bologna [Bologna] (UNIBO), Dipartimento di Ingegneria Industriale [Trento], University of Trento [Trento], Équipe Méthodes et Algorithmes en Commande (LAAS-MAC), Laboratoire d'analyse et d'architecture des systèmes (LAAS), Université Toulouse Capitole (UT Capitole), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut National des Sciences Appliquées (INSA)-Université Toulouse - Jean Jaurès (UT2J), Université de Toulouse (UT)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Université Toulouse Capitole (UT Capitole), Université de Toulouse (UT), Bosso A., Zaccarian L., Tilli A., and Barbieri M.
Subjects: Lyapunov method, Control and Optimization, Control and Systems Engineering, [INFO.INFO-AU]Computer Science [cs]/Automatic Control Engineering, Hysteresi, [INFO.INFO-SY]Computer Science [cs]/Systems and Control [cs.SY], switched systems, Prandtl-Ishlinskii operator
Abstract: International audience; We address the problem of setpoint regulation for cascaded minimum-phase linear systems interconnected through a scalar hysteresis, modeled as a Prandtl-Ishlinskii operator. Employing well-posed constrained differential inclusions to represent the hysteretic dynamics, we formulate the control problem in terms of stabilization of a compact set of equilibria depending on the hysteresis states. For our design, we firstly consider a proportional-integral controller for linear systems with hysteretic input, and provide model-free sufficient conditions based on high-gain arguments for closed-loop stability. Then, the controller is dynamically extended to obtain an inversion-free stabilizer of the overall cascade. For the presented schemes, we prove robust global asymptotic stability of a compact set that ensures setpoint regulation, regardless of the hysteresis states.
Published: 2023

27. Distributed Hybrid Observer With Prescribed Convergence Rate for a Linear Plant Using Multi-Hop Decomposition

Author: Riccardo Bertollo, Pablo Millan, Luis Orihuela, Alexandre Seuret, Luca Zaccarian, Università degli Studi di Trento (UNITN), Universidad Loyola Andalucía = Loyola University Andalucía, Universidad de Sevilla / University of Sevilla, Équipe Méthodes et Algorithmes en Commande (LAAS-MAC), Laboratoire d'analyse et d'architecture des systèmes (LAAS), Université Toulouse Capitole (UT Capitole), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut National des Sciences Appliquées (INSA)-Université Toulouse - Jean Jaurès (UT2J), Université de Toulouse (UT)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Université Toulouse Capitole (UT Capitole), Université de Toulouse (UT), and ANR-18-CE40-0010,HANDY,Systèmes Dynamiques Hybrides et en Réseau(2018)
Subjects: Hybrid observer, Control and Optimization, Input-to-State Stability, Sensor network, Control and Systems Engineering, [MATH.MATH-DS]Mathematics [math]/Dynamical Systems [math.DS], FOS: Mathematics, Distributed estimation, Linear systems, Dynamical Systems (math.DS), Mathematics - Dynamical Systems
Abstract: With a continuous-time formulation of the multihop decomposition, we propose a distributed hybrid observer for a sensor network where the plant and local observers run in continuous time and the information exchange among the sensing nodes is sampled-data. Process disturbances, measurement noise and communication noise are considered, and we prove that under some necessary detectability assumptions the observer gains can be tuned to guarantee exponential ISS with a prescribeda convergence rate. Simulations illustrate the performance of the proposed observer.
Published: 2023

28. A note on the wave equation controlled with a dynamic saturating boundary control

Author: Gauvrit, Mario, Prieur, Christophe, Tarbouriech, Sophie, Ecole Normale Supérieure Paris-Saclay (ENS Paris Saclay), GIPSA - Infinite Dimensional Dynamics (GIPSA-INFINITY), GIPSA Pôle Automatique et Diagnostic (GIPSA-PAD), Grenoble Images Parole Signal Automatique (GIPSA-lab), Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP ), Université Grenoble Alpes (UGA)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP ), Université Grenoble Alpes (UGA)-Grenoble Images Parole Signal Automatique (GIPSA-lab), Université Grenoble Alpes (UGA), Équipe Méthodes et Algorithmes en Commande (LAAS-MAC), Laboratoire d'analyse et d'architecture des systèmes (LAAS), Université Toulouse Capitole (UT Capitole), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut National des Sciences Appliquées (INSA)-Université Toulouse - Jean Jaurès (UT2J), Université de Toulouse (UT)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Université Toulouse Capitole (UT Capitole), Université de Toulouse (UT), Jochen Trumpf, Robert Mahony, and ANR-19-P3IA-0003,MIAI,MIAI @ Grenoble Alpes(2019)
Subjects: well-posedness, Control and Systems Engineering, saturation, Infinite-dimensional systems, stability, [SPI.AUTO]Engineering Sciences [physics]/Automatic
Abstract: International audience; This paper studies the nonlinear systems obtained by considering a wave equation in closed loop with a nonlinear dynamical boundary controller. The controller is subject to a magnitude limitation and modeled by a linear ordinary differential equation with a saturation map in the input. The well-posedness of the obtained infinite-dimensional system is first studied and then two stability results are given. These two stability results apply for two cascade cases and give sufficient conditions for the asymptotic stability of the equilibrium. The well-posedness is proven by using nonlinear semigroups techniques, whereas the global asymptotic stability results are obtained by Lyapunov-based arguments in infinite-dimensional state space.
Published: 2023

29. Hybrid Control of Self-Oscillating Resonant Converters With Three-Level Input

Author: Nicola Zaupa, Carlos Olalla, Isabelle Queinnec, Luis Martinez-Salamero, Luca Zaccarian, Équipe Méthodes et Algorithmes en Commande (LAAS-MAC), Laboratoire d'analyse et d'architecture des systèmes (LAAS), Université Toulouse Capitole (UT Capitole), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut National des Sciences Appliquées (INSA)-Université Toulouse - Jean Jaurès (UT2J), Université de Toulouse (UT)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Université Toulouse Capitole (UT Capitole), Université de Toulouse (UT), Université Toulouse III - Paul Sabatier (UT3), Universitat Rovira i Virgili, Dipartimento di Ingegneria Industriale [Trento], University of Trento [Trento], Spanish Ministry of Science and Innovation (Grant Number: PID2019-111443RB-100 and PID2020-120151RB-I00), MUR through PRIN Grant DOCEAT (Grant Number: 2020RTWES4), and ANR-18-CE40-0010,HANDY,Systèmes Dynamiques Hybrides et en Réseau(2018)
Subjects: Control and Optimization, Control and Systems Engineering, Power electronics, [SPI.NRJ]Engineering Sciences [physics]/Electric power, Stability of hybrid systems, Lyapunov methods, [SPI.AUTO]Engineering Sciences [physics]/Automatic
Abstract: International audience; We propose a hybrid feedback law inducing self-oscillating behavior in second-order resonant converters. With our controller, the converter switches at the resonant frequency of its tank, without the need of external oscillators. In addition, the output amplitude can be adjusted by a reference signal ranging from zero to π /2. The amplitude modulation is then performed while maintaining an approximately constant switching frequency. Theoretical results show uniqueness and almost global asymptotic stability of a nontrivial hybrid limit cycle. Experimental results show that a circuit implementing the new controller successfully matches the desirable simulated behavior.
Published: 2023

30. Non-identifiability visualisation algorithms

Author: Munier, Nathanaël, Soubies, Emmanuel, Weiss, Pierre, Institut de Mathématiques de Toulouse UMR5219 (IMT), Université Toulouse Capitole (UT Capitole), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut National des Sciences Appliquées (INSA)-Université Toulouse - Jean Jaurès (UT2J), Université de Toulouse (UT)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS), Centre de Biologie Intégrative (CBI), Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS), Signal et Communications (IRIT-SC), Institut de recherche en informatique de Toulouse (IRIT), Université de Toulouse (UT)-Université de Toulouse (UT)-Université Toulouse - Jean Jaurès (UT2J), Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Toulouse Mind & Brain Institut (TMBI), Université Toulouse - Jean Jaurès (UT2J), Université de Toulouse (UT)-Université de Toulouse (UT)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université Toulouse Capitole (UT Capitole), Université de Toulouse (UT), Groupe de Recherche et d'Etudes de Traitement du Signal et des Images, ANR-21-CE48-0008,MICROBLIND,Problèmes inverses aveugles et microscopie optique(2021), and ANR-11-LABX-0040,CIMI,Centre International de Mathématiques et d'Informatique (de Toulouse)(2011)
Subjects: Problème inverse, [INFO.INFO-TI]Computer Science [cs]/Image Processing [eess.IV], Identifiabilité, [INFO]Computer Science [cs], [INFO.INFO-CG]Computer Science [cs]/Computational Geometry [cs.CG], [SPI.SIGNAL]Engineering Sciences [physics]/Signal and Image processing
Abstract: International audience; The identification of a set of parameters x from observed data y is often reduced to the resolution of a problem of the type f(x) = y, where f is a continuous application. This equation appears in domains such as (blind) inverse problems, data assimilation, or optimal control. When the solution is not unique, it may be important to inform the user about the set of plausible solutions. We propose here an algorithm to locally describe a set of solutions of this equation. It is essentially based on automatic differentiation and on a local parameterization of the solution manifold. We illustrate the interest of this approach on two toy examples.; L'identification d'un ensemble de paramètres x à partir de données observées y est souvent réduite à la résolution d'un problème du type f(x) = y, où f est une application continue. Cette équation apparaît dans des domaines tels que les problèmes inverses (aveugles), l'assimilation de données ou encore le contrôle optimal. Lorsque la solution n'est pas unique, il peut être important d'en informer l'utilisateur et de le renseigner sur l'ensemble des solutions plausibles. Nous proposons ici un algorithme permettant de décrire localement un ensemble de solutions de cette équation. Il repose essentiellement sur la différentiation automatique et sur une paramétrisation locale de la variété des solutions. Nous illustrons l'intérêt de cette approche sur deux exemples jouets.
Published: 2023

31. Tests statistiques pour l'analyse d'acquisitions hyperspectrales codées

Author: Dinh, Trung-Tin, Carfantan, Hervé, Monmayrant, Antoine, Lacroix, Simon, Institut de recherche en astrophysique et planétologie (IRAP), Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Centre National de la Recherche Scientifique (CNRS), Laboratoire d'analyse et d'architecture des systèmes (LAAS), Université Toulouse Capitole (UT Capitole), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut National des Sciences Appliquées (INSA)-Université Toulouse - Jean Jaurès (UT2J), Université de Toulouse (UT)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT), and GRETSI
Subjects: [INFO.INFO-TS]Computer Science [cs]/Signal and Image Processing, [PHYS.PHYS.PHYS-DATA-AN]Physics [physics]/Physics [physics]/Data Analysis, Statistics and Probability [physics.data-an]
Abstract: Co-designed and programmable hyperspectral imagers, based on computational imaging, can greatly reduce theacquisition time of hyperspectral scenes. They rely on the measurement of one or a few coded images combined with a model (to compensate for the lack of data) and allow to estimate the hyperspectral scene while reducing the amount of data and the acquisition time by an order of magnitude or more. The adequacy of the model to the observed scene is the sine qua none condition for an accurate estimation. Here we study a separability assumption of the scene over homogeneous regions, which is similar to accounting for intraclass variability in supervised spectral classification, and use statistical tests to verify this model from the coded data.; -Des imageurs hyperspectraux co-conçus et programmables, relevant de l'imagerie computationnelle, permettent aujourd'hui de réduire fortement le temps d'acquisition de scènes hyperspectrales. Ils reposent sur la mesure d'une ou de quelques images codées, qui associées à un modèle palliant le manque de données, permettent d'estimer toute la scène hyperspectrale en réduisant la quantité de données et le temps d'acquisition d'un ordre de grandeur ou plus. L'adéquation du modèle à la scène observée est la condition sine qua none d'une estimation fidèle. Nous proposons ici d'étudier un modèle de séparabilité de la scène sur des régions homogènes, similaire à la prise en compte de la variabilité intraclasse en classification spectrale supervisée, et utilisons des tests statistiques pour vérifier ce modèle à partir des données codées.
Published: 2023

32. Blossom: an Anytime Algorithm for Computing Optimal Decision Trees

Author: Demirović, Emir, Hebrard, Emmanuel, Jean, Louis, Delft University of Technology (TU Delft), Équipe Recherche Opérationnelle, Optimisation Combinatoire et Contraintes (LAAS-ROC), Laboratoire d'analyse et d'architecture des systèmes (LAAS), Université Toulouse Capitole (UT Capitole), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut National des Sciences Appliquées (INSA)-Université Toulouse - Jean Jaurès (UT2J), Université de Toulouse (UT)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Université Toulouse Capitole (UT Capitole), Université de Toulouse (UT), Jolibrain, Barbara Engelhardt, Emma Brunskill, Kyunghyun Cho, and ANR-19-P3IA-0004,ANITI,Artificial and Natural Intelligence Toulouse Institute(2019)
Subjects: Decision Trees, Search, [INFO]Computer Science [cs]
Abstract: International audience; We propose a simple algorithm to learn optimal decision trees of bounded depth. This algorithm is essentially an anytime version of the state-ofthe-art dynamic programming approach. It has virtually no overhead compared to heuristic methods and is comparable to the best exact methods to prove optimality on most data sets. Experiments show that whereas existing exact methods hardly scale to deep trees, this algorithm learns trees comparable to standard heuristics without computational overhead, and can significantly improve their accuracy when given more computation time, even for deep trees.
Published: 2023

33. Fiber crosslinking drives the emergence of order in a 3D dynamical network model

Author: Chassonnery, Pauline, Paupert, Jenny, Lorsignol, Anne, Sévérac, Childérick, Ousset, Marielle, Degond, Pierre, Casteilla, Louis, Peurichard, Diane, Geroscience and rejuvenation research center (RESTORE), Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-EFS-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS), Inria de Paris, Institut National de Recherche en Informatique et en Automatique (Inria), Institut de Mathématiques de Toulouse UMR5219 (IMT), Université Toulouse Capitole (UT Capitole), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut National des Sciences Appliquées (INSA)-Université Toulouse - Jean Jaurès (UT2J), Université de Toulouse (UT)-Université Toulouse III - Paul Sabatier (UT3), and Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS)
Subjects: Self-organization, Architecture emergence, Biological Physics (physics.bio-ph), MSC: 92-10, 92C10, 82C22, 93A16, FOS: Physical sciences, Three dimensional mathematical modelling, Physics - Biological Physics, Extracellular matrix, Dynamical crosslinking, [PHYS.MECA.BIOM]Physics [physics]/Mechanics [physics]/Biomechanics [physics.med-ph], [MATH]Mathematics [math]
Abstract: The Extra-Cellular-Matrix (ECM) is a complex interconnected 3D network that provides structural support for the cells and tissues and defines organ architecture key for their healthy functioning. However, the intimate mechanisms by which ECM acquire their 3D architecture are still largely unknown. In this paper, we address this question by means of a 3D individual based model of interacting fibers able to spontaneously crosslink or unlink to each other and align at the crosslinks. We show that such systems are able to spontaneously generate different types of architectures. We provide a thorough analysis of the emerging structures by an exhaustive parametric analysis and the use of appropriate visualization tools and quantifiers in 3D. The most striking result is that the emergence of ordered structures can be fully explained by a single emerging variable : the proportion of crosslinks in the network. This simple variable becomes an important putative target to control and predict the structuring of biological tissues, to suggest possible new therapeutic strategies to restore tissue functions after disruption, and to help in the development of collagen-based scaffolds for tissue engineering. Moreover, the model reveals that the emergence of architecture is a spatially homogeneous process following a unique evolutionary path, and highlights the essential role of dynamical crosslinking in tissue structuring., Comment: 28 pages, 12 figures, 2 tables
Published: 2023

34. Development of VCSELs for cyogenic (4.2 K) optical interfaces

Author: Almuneau, Guilhem, Équipe Photonique (LAAS-PHOTO), Laboratoire d'analyse et d'architecture des systèmes (LAAS), Université Toulouse Capitole (UT Capitole), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut National des Sciences Appliquées (INSA)-Université Toulouse - Jean Jaurès (UT2J), Université de Toulouse (UT)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Université Toulouse Capitole (UT Capitole), and Université de Toulouse (UT)
Subjects: [PHYS]Physics [physics], VCSEL LD Laser cryogenic, LD, Laser, cryogenic, VCSEL
Abstract: International audience; Vertical cavity surface emitting lasers operating at 4.2K are developed for energy efficient optical links between cryogenic systems and room-temperature data storage systems. Design considerations, material models, and validation of required electro-optical-thermal models are presented. Successful operation at mA-level injection is demonstrated.
Published: 2023

35. Co-designing versatile quadruped robots for dynamic and energy-efficient motions

Author: Fadini, Gabriele, Kumar, Shivesh, Kumar, Rohit, Flayols, Thomas, Prete, Andrea, Carpentier, Justin, Souères, Philippe, Équipe Mouvement des Systèmes Anthropomorphes (LAAS-GEPETTO), Laboratoire d'analyse et d'architecture des systèmes (LAAS), Université Toulouse Capitole (UT Capitole), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut National des Sciences Appliquées (INSA)-Université Toulouse - Jean Jaurès (UT2J), Université de Toulouse (UT)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Université Toulouse Capitole (UT Capitole), Université de Toulouse (UT), Université Toulouse III - Paul Sabatier (UT3), Deutsches Forschungszentrum für Künstliche Intelligenz GmbH = German Research Center for Artificial Intelligence (DFKI), University of Trento [Trento], Inria de Paris, Institut National de Recherche en Informatique et en Automatique (Inria), Département d'informatique - ENS Paris (DI-ENS), École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Institut National de Recherche en Informatique et en Automatique (Inria)-Centre National de la Recherche Scientifique (CNRS), M-RoCK (FKZ 01IW21002) project funded by the German Aerospace Center (DLR) with federal funds from the Federal Ministry of Education and Research, ANR-10-EQPX-4401,ROBOTEX 2.0,ANR-10-EQPX-44-01, ANR-21-ESRE-0015,TIRREX,Infrastructure technologique pour la recherche d'excellence en robotique(2021), ANR-19-P3IA-0001,PRAIRIE,PaRis Artificial Intelligence Research InstitutE(2019), and European Project: 101070165,AGIMUS
Subjects: Methods and Tools for Robot System Design Optimization and Optimal Control Simulation and Animation Mechanism Design, Mechanism Design, Methods and Tools for Robot System Design, Simulation and Animation, Optimization and Optimal Control, [INFO.INFO-RB]Computer Science [cs]/Robotics [cs.RO], [PHYS.MECA.GEME]Physics [physics]/Mechanics [physics]/Mechanical engineering [physics.class-ph], [MATH.MATH-OC]Mathematics [math]/Optimization and Control [math.OC]
Abstract: This paper presents a bi-level optimization framework to concurrently optimize a quadruped hardware and control policies for achieving dynamic cyclic behaviors. The longterm vision to drive the design of dynamic and efficient robots by means of computational techniques is applied to improve the development of a new quadruped prototype. The scale of the robot and its actuators are optimized for energy efficiency considering a complete model of the motor, that includes friction, torque, and bandwidth limitations. This model is used to optimize the power consumption during bounding and backflip tasks and is validated by tracking the output trajectories on the first prototype iteration. The co-design results show an improvement of up to 87% for a single task optimization. It appears that, for jumping forward, robots with longer thighs perform better, while for backflips, longer shanks are better suited. To understand the trade-off between these different choices, a Pareto set is constructed to guide the design of the next prototype.
Published: 2023

36. Asymptotic study of an anisotropic Fokker-Planck collision operator in a strong magnetic field

Author: Lehman, Étienne, Negulescu, Claudia, Possanner, Stefan, Institut de Mathématiques de Toulouse UMR5219 (IMT), Université Toulouse Capitole (UT Capitole), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut National des Sciences Appliquées (INSA)-Université Toulouse - Jean Jaurès (UT2J), Université de Toulouse (UT)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS), and Max-Planck-Institut für Plasmaphysik [Garching] (IPP)
Subjects: hybrid kinetic/fluid model, truncation, [MATH.MATH-MP]Mathematics [math]/Mathematical Physics [math-ph], [PHYS.PHYS.PHYS-PLASM-PH]Physics [physics]/Physics [physics]/Plasma Physics [physics.plasm-ph], Anisotropic fusion plasma, strong magnetic fields, Hilbert expansion, strong perpendicular collisionality, asymptotic limits
Abstract: The present paper is concerned with the derivation, via asymptotic studies, of a reduced hybrid model describing the anisotropic fusion plasma dynamics in tokamaks. The parallel dynamics is governed by a kinetic equation, whereas the perpendicular dynamics is described by a Maxwellian distribution function, whose temperature T ⊥ satisfies an evolution equation, exchanging information with the parallel direction via some coupling terms. The reduced model is obtained from the underlying fully kinetic model, under the assumption of a strong magnetic field and strong collisionality in the perpendicular direction. From a numerical point of view, reduced models are very advantageous, permitting significant savings in computational times and memory. To improve the precision of the reduced description, we propose in this paper also first order correction terms with respect to the parameter describing the anisotropy, and discuss these terms from a physical point of view. This first order truncated model is new to our knowledge, meets the desired requirements of precision and efficiency, and its derivation is clearly exposed in this work, based on formal asymptotic studies.
Published: 2023

37. The Coble Quadric

Author: Benedetti, Vladimiro, Faenzi, Daniele, Bolognesi, Michele, Manivel, L, Institut de Mathématiques de Bourgogne [Dijon] (IMB), Université de Bourgogne (UB)-Université Bourgogne Franche-Comté [COMUE] (UBFC)-Centre National de la Recherche Scientifique (CNRS), Institut Montpelliérain Alexander Grothendieck (IMAG), Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS), Institut de Mathématiques de Toulouse UMR5219 (IMT), Université Toulouse Capitole (UT Capitole), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut National des Sciences Appliquées (INSA)-Université Toulouse - Jean Jaurès (UT2J), Université de Toulouse (UT)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS), Feder Bourgogne, Région Bourgogne-Franche-Comté, ANR-20-CE40-0023,FanoHK,Des variétés de Fano aux hyperkählériennes : géométrie et catégories dérivées(2020), ANR-21-CE40-0017,BRIDGES,Interactions Brésil-France en théorie de jauge, structures extrémales et stabilité(2021), ANR-17-EURE-0002,EIPHI,Ingénierie et Innovation par les sciences physiques, les savoir-faire technologiques et l'interdisciplinarité(2017), Benedetti, Vladimiro, Des variétés de Fano aux hyperkählériennes : géométrie et catégories dérivées - - FanoHK2020 - ANR-20-CE40-0023 - AAPG2020 - VALID, Interactions Brésil-France en théorie de jauge, structures extrémales et stabilité - - BRIDGES2021 - ANR-21-CE40-0017 - AAPG2021 - VALID, and Ingénierie et Innovation par les sciences physiques, les savoir-faire technologiques et l'interdisciplinarité - - EIPHI2017 - ANR-17-EURE-0002 - EURE - VALID
Subjects: Coble hypersurfaces, Mathematics - Algebraic Geometry, degeneracy loci, [MATH.MATH-AG] Mathematics [math]/Algebraic Geometry [math.AG], FOS: Mathematics, 14h60, 22E46, Moduli spaces of stable bundles, subvarieties of Grassmannians, [MATH.MATH-AG]Mathematics [math]/Algebraic Geometry [math.AG], Hecke lines, self-dual hypersurfaces, Algebraic Geometry (math.AG)
Abstract: Given a smooth genus three curve $C$, the moduli space of rank two stable vector bundles on C with trivial determinant embeds in $\mathbb{P}^8$ as a hypersurface whose singular locus is the Kummer threefold of $C$; this hypersurface is the Coble quartic. Gruson, Sam and Weyman realized that this quartic could be constructed from a general skew-symmetric fourform in eight variables. Using the lines contained in the quartic, we prove that a similar construction allows to recover SU$_C(2, L)$, the moduli space of rank two stable vector bundles on C with fixed determinant of odd degree L, as a subvariety of $G(2, 8)$. In fact, each point $p \in C$ defines a natural embedding of SU$_C(2, \mathcal{O}(p))$ in $G(2, 8)$. We show that, for the generic such embedding, there exists a unique quadratic section of the Grassmannian which is singular exactly along the image of SU$_C(2, \mathcal{O}(p))$, and thus deserves to be coined the Coble quadric of the pointed curve $(C, p)$.
Published: 2023

38. A Closed-Loop Framework-Independent Bridge from AIPlan4EU's Unified Planning Platform to Embedded Systems

Author: Hastham Sathiya Satchi Sadanandam, Selvakumar, Stock, Sebastian, Sung, Alexander, Ingrand, Félix, Lima, Oscar, Vinci, Marc, Hertzberg, Joachim, Équipe Robotique et InteractionS (LAAS-RIS), Laboratoire d'analyse et d'architecture des systèmes (LAAS), Université Toulouse Capitole (UT Capitole), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut National des Sciences Appliquées (INSA)-Université Toulouse - Jean Jaurès (UT2J), Université de Toulouse (UT)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Université Toulouse Capitole (UT Capitole), Université de Toulouse (UT), Deutsches Forschungszentrum für Künstliche Intelligenz GmbH = German Research Center for Artificial Intelligence (DFKI), GMD - Forschungszentrum Informationstechnik GmbH (GMD), Federal Republic of Germany, ANR-19-P3IA-0004,ANITI,Artificial and Natural Intelligence Toulouse Institute(2019), and European Project: 101016442,AIPlan4EU
Subjects: [INFO.INFO-RB]Computer Science [cs]/Robotics [cs.RO]
Abstract: International audience; The main goal of the AIPlan4EU project is to give easy and unified access to a large and diversified number of planning technologies and approaches. Yet, to make beneficial use of the produced plans, the project also develops and deploys Technology Specific Bridges (TSB) to connect and close the loop with real-world applications. In this paper we present one of these bridges which specifically targets robotic applications and more generally embedded systems. In these systems, planning and plan execution lead to commands on effectors in the real world, while sensors, intrinsic and extrinsic, report on the state of the world, which is then fed back to monitor the plan execution, with replanning or plan repair when needed. To this effect, we have developed a Python library that simplifies the creation of planning domains for existing applications and allows to execute and monitor resulting plans. Despite being developed for robotic applications, the library is not dependent on a specific robot framework, nor any middleware, and can also be used for non-robotic domains. We demonstrate this TSB on two robotic experiments: a ROS (Quigley et al. 2009) based service robot and a GenoM (Dal Zilio et al. 2023) based multi drones application.
Published: 2023

39. Diagnosabilization of Time Petri net for timed fault

Author: Coquand, Camille, Pencolé, Yannick, Subias, Audine, Équipe DIagnostic, Supervision et COnduite (LAAS-DISCO), Laboratoire d'analyse et d'architecture des systèmes (LAAS), Université Toulouse Capitole (UT Capitole), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut National des Sciences Appliquées (INSA)-Université Toulouse - Jean Jaurès (UT2J), Université de Toulouse (UT)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Université Toulouse Capitole (UT Capitole), Université de Toulouse (UT), and IFAC
Subjects: [INFO.INFO-AU]Computer Science [cs]/Automatic Control Engineering, Time Petri nets, diagnosabilization, Discrete event system, Discrete event system Time Petri nets diagnosabilization critical pair, critical pair
Abstract: International audience; Diagnosability is the property of a system to have sufficient observable information to guarantee the diagnosis of a fault. Here, the considered fault is a timed fault, i.e. an unobservable event that occurs in bounded time since the start of the system. Starting with a system modeled as a Time Petri net that is not diagnosable, this work proposes a method that provides adjustments by restriction of static time intervals to ensure the system becomes ∆-diagnosable for that fault. These adjustments are characterized by a set of constraints over interval bounds and then provide a set of solutions, if any, to ensure the diagnosability of the system.
Published: 2023

40. Fault detection combining adaptive degrees of freedom χ2-statistics and interval approach for nonlinear systems

Author: Lu, Quoc Hung, Fergani, Soheib, Jauberthie, Carine, Équipe DIagnostic, Supervision et COnduite (LAAS-DISCO), Laboratoire d'analyse et d'architecture des systèmes (LAAS), Université Toulouse Capitole (UT Capitole), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut National des Sciences Appliquées (INSA)-Université Toulouse - Jean Jaurès (UT2J), Université de Toulouse (UT)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Université Toulouse Capitole (UT Capitole), and Université de Toulouse (UT)
Subjects: Automotive quarter model, Adaptive Innovation-based method, Adaptive amplifier coefficient, Fault diagnosis, [SPI.AUTO]Engineering Sciences [physics]/Automatic
Abstract: International audience; An enlargement of the Adaptive degrees of freedom χ2-statistics (ADFC) method to fault detection for nonlinear systems with mixed uncertainties (stochastic and bounded uncertainties) is presented in this paper. The ADFC approach, primarily developped for fault detection in case of linear systems, is then combined with the Reinforced likelihood box particle filter (RLBPF). A residual generator is used, followed by the adaptive amplifier coefficient(a.a.c.) concept in the decision making stage. Then, the proposed approach is applied to a nonlinear Magneto-Rheological damper model to illustrate the efficiency of the met.
Published: 2023

41. Fault detection using Enhanced Adaptive degrees of freedom χ2-statistics method for Linear systems with mixed uncertainties

Author: Lu, Quoc Hung, Fergani, Soheib, Jauberthie, Carine, Équipe DIagnostic, Supervision et COnduite (LAAS-DISCO), Laboratoire d'analyse et d'architecture des systèmes (LAAS), Université Toulouse Capitole (UT Capitole), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut National des Sciences Appliquées (INSA)-Université Toulouse - Jean Jaurès (UT2J), Université de Toulouse (UT)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Université Toulouse Capitole (UT Capitole), and Université de Toulouse (UT)
Subjects: Automotive bicycle mode, Adaptive Innovation-based method, Adaptive amplifier coefficient, Fault diagnosis, [SPI.AUTO]Engineering Sciences [physics]/Automatic
Abstract: International audience; This article is concerned with a fault detection enhancement method using adaptive amplifier coefficients (a.a.c.) concept. It is developed for linear systems with mixed uncertainties (stochastic and bounded uncertainties framework). The study provides, also, analysis and discussions about the applicability and the efficiency of the enhanced method to several sensors fault error types. Simulations on a vehicle bicycle model (validated by experimental tests on the Renault Megane) are presented to emphasize on the performances of the developed method.
Published: 2023

42. Fast and Robust Resource-Constrained Scheduling with Graph Neural Networks

Author: Teichteil-Königsbuch, Florent, Povéda, Guillaume, González de Garibay Barba, Guillermo, Luchterhand, Tim, Thiébaux, Sylvie, Airbus central R&T, AI research, Airbus Group [Madrid], Université de Toulouse (UT), Institut National des Sciences Appliquées (INSA), Équipe Recherche Opérationnelle, Optimisation Combinatoire et Contraintes (LAAS-ROC), Laboratoire d'analyse et d'architecture des systèmes (LAAS), Université Toulouse Capitole (UT Capitole), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut National des Sciences Appliquées (INSA)-Université Toulouse - Jean Jaurès (UT2J), Université de Toulouse (UT)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Université Toulouse Capitole (UT Capitole), Équipe Robotique et InteractionS (LAAS-RIS), Australian National University (ANU), Airbus R&T, ARC grant DP220103815, and European Project: 101070149,TUPLES
Subjects: Machine Learning, Optimisation in Hindsight, Scheduling, Stochastic Durations, Graph Neural Networks, Resource Constrained Project Scheduling, Constraint Programming, [INFO.INFO-AI]Computer Science [cs]/Artificial Intelligence [cs.AI]
Abstract: International audience; Resource-Constrained Project Scheduling Problems (RCPSPs) are NP-complete, which makes it challenging to efficiently solve large instances and robustify solutions in the presence of uncertainty. To remedy this, we learn to efficiently mimic the solutions produced by Constraint Programming (CP) solver, using a Graph Neural Network (GNN) architecture designed to capture the structure of RCPSPs. Since the GNN solution may violate constraints, we ensure schedule feasibility at inference time by extracting the task ordering from the GNN schedule and post-processing it with the well-known Schedule Generation Scheme (SGS). We find that SIREN, the resulting algorithm, produces schedules that are of higher quality than those produced by the CP solver within the same computation time budget. The speed and solution quality of SIREN make it suitable as a component of an on-line scenario-based optimisation procedure for RCPSPs with stochastic durations. This leads to the SERENE system, which robustly selects, in real-time, the best next tasks to start in order to minimise the average makespan over the scenarios. Empirically, SERENE achieves better average makespan over different realisations of uncertainty than deterministic algorithms that continuously reschedule on the basis of either the worst, best or average task durations.
Published: 2023

43. Enhancing Operational Deliberation in a Refinement Acting Engine with Continuous Planning

Author: Turi, Jérémy, Bit-Monnot, Arthur, Ingrand, Félix, Équipe Robotique et InteractionS (LAAS-RIS), Laboratoire d'analyse et d'architecture des systèmes (LAAS), Université Toulouse Capitole (UT Capitole), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut National des Sciences Appliquées (INSA)-Université Toulouse - Jean Jaurès (UT2J), Université de Toulouse (UT)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Université Toulouse Capitole (UT Capitole), Université de Toulouse (UT), Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT), ANR-19-P3IA-0004,ANITI,Artificial and Natural Intelligence Toulouse Institute(2019), and European Project: 101016442,AIPlan4EU
Subjects: [INFO.INFO-CL]Computer Science [cs]/Computation and Language [cs.CL], [INFO.INFO-AI]Computer Science [cs]/Artificial Intelligence [cs.AI]
Abstract: International audience; Recent technological developments in robotics and artificial intelligence may enable the deployment of robots in many aspects of our lives. As the complexity of robotic platforms increases, deliberation algorithms need to be improved, in particular to handle an increasing number of agents, to manage complex goals and tasks, and to evolve in more open environments in which unforeseen events should be dealt with autonomously. Among the deliberation functionalities deployed to provide the best level of autonomy: planning, monitoring, learning, observing, we focus here on acting. We present OMPAS, a refinement-based acting engine that executes high-level tasks by refining them into a set of lowerlevel tasks and commands. OMPAS uses a custom Lisp dialect (SOMPAS) to define the behavior of the robotic agent. SOMPAS provides primitives to handle concurrency and resources, and allows the synthesis of planning models, thanks to the restricted core language, and the explicit identification of acting decisions. The engine has been extended to deploy a continuous planning module, using the synthesized models, to look ahead and guide the decisions of the acting system in order to e.g., avoid deadlock, or optimize the completion of several parallel tasks. We provide an evaluation of the overall approach on the control of a fleet of robots in a simulated logistic platform.
Published: 2023

44. Anticipating False Beliefs and Planning Pertinent Reactions in Human-Aware Task Planning with Models of Theory of Mind

Author: Favier, Anthony, Shekhar, Shashank, Alami, Rachid, Équipe Robotique et InteractionS (LAAS-RIS), Laboratoire d'analyse et d'architecture des systèmes (LAAS), Université Toulouse Capitole (UT Capitole), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut National des Sciences Appliquées (INSA)-Université Toulouse - Jean Jaurès (UT2J), Université de Toulouse (UT)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Université Toulouse Capitole (UT Capitole), Université de Toulouse (UT), and ANR-19-P3IA-0004,ANITI,Artificial and Natural Intelligence Toulouse Institute(2019)
Subjects: [INFO.INFO-RB]Computer Science [cs]/Robotics [cs.RO], [INFO.INFO-HC]Computer Science [cs]/Human-Computer Interaction [cs.HC]
Abstract: International audience; It is essential for a collaborative robot to consider Theory of Mind (ToM) when interacting with humans. Indeed, performing an action in the absence of another agent may create false beliefs like in the well-known Sally & Anne Task (Wimmer and Perner 1983). The robot should be able to detect, react to, and even anticipate false beliefs of other agents with a detrimental impact on the task to achieve. Currently, ToM is mainly used to control the task execution and resolve in a reactive way the detrimental false beliefs. Some works introduce ToM at the planning level by considering distinct beliefs, and we are in this context. This work proposes an extension of an existing human-aware task planner and effectively allows the robot to anticipate a false human belief ensuring a smooth collaboration through an implicitly coordinated plan. First, we propose to capture the observability properties of the environment in the state description using two observability types and the notion of co-presence. They allow us to maintain distinct agent beliefs by reasoning directly on what agents can observe through specifically modeled Situation Assessment processes, instead of reasoning of action effects. Then, thanks to the better estimated human beliefs, we can predict if a false belief with adverse impact will occur. If that is the case then, first, the robot's plan can be to communicate minimally and proactively. Second, if this false belief is due to a non-observed robot action, the robot's plan can be to postpone this action until it can be observed by the human, avoiding the creation of the false belief. We implemented our new conceptual approach, prove its soundness and completeness, discuss its effectiveness qualitatively, and show experimental results on three novel domains.
Published: 2023

45. Invertibility of functionals of the Poisson process and applications

Author: Coutin, Laure, Decreusefond, Laurent, Institut de Mathématiques de Toulouse UMR5219 (IMT), Université Toulouse Capitole (UT Capitole), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut National des Sciences Appliquées (INSA)-Université Toulouse - Jean Jaurès (UT2J), Université de Toulouse (UT)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS), Département Informatique et Réseaux (INFRES), Télécom ParisTech, Réseaux, Mobilité et Services (RMS), Laboratoire Traitement et Communication de l'Information (LTCI), Institut Mines-Télécom [Paris] (IMT)-Télécom Paris-Institut Mines-Télécom [Paris] (IMT)-Télécom Paris, and Institut Mines-Télécom [Paris] (IMT)-Télécom Paris
Subjects: [MATH.MATH-PR]Mathematics [math]/Probability [math.PR], Girsanov Theorem, Probability (math.PR), FOS: Mathematics, Invertibility, Random Time Change, 60G55, Hawkes processes, Mathematics - Probability
Abstract: Following previous investigations by {\"U}st{\"u}nel [22] about the invertibility of some transformations on the Wiener space, we find some entropic conditions under which a random change of time is invertible on the Poisson space. As a consequence, we provide a new construction of Hawkes processes. We also establish a new variational representation of the entropy.
Published: 2023

46. Local exact controllability to the steady states of a parabolic system with coupled nonlinear boundary conditions

Author: Bhandari, Kuntal, Boyer, Franck, Institute of Mathematics of the Czech Academy of Science (IM / CAS), Czech Academy of Sciences [Prague] (CAS), Institut de Mathématiques de Toulouse UMR5219 (IMT), Université Toulouse Capitole (UT Capitole), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut National des Sciences Appliquées (INSA)-Université Toulouse - Jean Jaurès (UT2J), Université de Toulouse (UT)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS), Institut Universitaire de France (IUF), and Ministère de l'Education nationale, de l’Enseignement supérieur et de la Recherche (M.E.N.E.S.R.)
Subjects: method of moments, Parabolic systems, fixed-point argument, boundary controllability, [MATH.MATH-AP]Mathematics [math]/Analysis of PDEs [math.AP], [MATH.MATH-OC]Mathematics [math]/Optimization and Control [math.OC], source term method
Abstract: In this article, we study the boundary local exact controllability to any steady state of a one-dimensional parabolic system with coupled nonlinear boundary conditions by means of only one control. The significant point is that the state components are interacting only at the boundary points in terms of some nonlinear terms. We consider two cases : either the control function is acting through a mixed nonlinear boundary condition on the first component or through a Neumann condition on the second component. The results are slightly different in the two cases. To study this problem, we first consider the associated linearized systems around the given steady state. The method of moments let us to prove its controllability and to obtain a suitable estimate of the control cost of the form $Me^{M/T}$. To this end, we need to develop a precise spectral analysis of a non self-adjoint operator. Thanks to those preliminary results, we can use the source term method developed in [Liu-Takahashi-Tucsnak 2013], followed by the Banach fixed point argument, to obtain the small-time local boundary exact controllability to the steady state for the original system.
Published: 2023

47. On Markov intertwining relations and primal conditioning

Author: Arnaudon, Marc, Coulibaly-Pasquier, Koléhè, Miclo, Laurent, Institut de Mathématiques de Bordeaux (IMB), Université Bordeaux Segalen - Bordeaux 2-Université Sciences et Technologies - Bordeaux 1 (UB)-Université de Bordeaux (UB)-Institut Polytechnique de Bordeaux (Bordeaux INP)-Centre National de la Recherche Scientifique (CNRS), Institut Élie Cartan de Lorraine (IECL), Université de Lorraine (UL)-Centre National de la Recherche Scientifique (CNRS), Institut de Mathématiques de Toulouse UMR5219 (IMT), Université Toulouse Capitole (UT Capitole), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut National des Sciences Appliquées (INSA)-Université Toulouse - Jean Jaurès (UT2J), Université de Toulouse (UT)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS), and AFOSR-22IOE016
Subjects: Algebraic and probabilistic Markov intertwining relations, MSC2020: primary: 60J10, secondary: 15B51, Doob transform, discrete Pitman intertwining, top-to-random shuffle, subset conditioning, [MATH]Mathematics [math], birth-and-death Markov chains, strong stationary times
Abstract: Given an intertwining relation between two finite Markov chains, we investigate how it can be transformed by conditioning the primal Markov chain to stay in a proper subset. A natural assumption on the underlying link kernel is put forward. The three classical examples of discrete Pitman, top-torandom shuffle and absorbed birth-and-death chain intertwinings serve as illustrations.
Published: 2023

48. Epitaxie localisée de P-GaN par EJM pour la fabrication de HEMTs AlGaN/GaN normally-off

Author: Rouly, Daniel, Tasselli, Josiane, Austin, Patrick, Cordier, Yvon, Courville, Aimeric, Vaurette, Francois, Lecestre, Aurélie, Reig, Benjamin, Isoird, Karine, Morancho, Frédéric, Équipe Intégration de Systèmes de Gestion de l'Énergie (LAAS-ISGE), Laboratoire d'analyse et d'architecture des systèmes (LAAS), Université Toulouse Capitole (UT Capitole), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut National des Sciences Appliquées (INSA)-Université Toulouse - Jean Jaurès (UT2J), Université de Toulouse (UT)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Université Toulouse Capitole (UT Capitole), Université de Toulouse (UT), Centre de recherche sur l'hétéroepitaxie et ses applications (CRHEA), Université Nice Sophia Antipolis (1965 - 2019) (UNS), COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Centre National de la Recherche Scientifique (CNRS)-Université Côte d'Azur (UCA), Institut d’Électronique, de Microélectronique et de Nanotechnologie - UMR 8520 (IEMN), Centrale Lille-Université de Lille-Centre National de la Recherche Scientifique (CNRS)-Université Polytechnique Hauts-de-France (UPHF)-JUNIA (JUNIA), Université catholique de Lille (UCL)-Université catholique de Lille (UCL), Centrale de Micro Nano Fabrication - IEMN (CMNF - IEMN), Université catholique de Lille (UCL)-Université catholique de Lille (UCL)-Centrale Lille-Université de Lille-Centre National de la Recherche Scientifique (CNRS)-Université Polytechnique Hauts-de-France (UPHF)-JUNIA (JUNIA), Service Techniques et Équipements Appliqués à la Microélectronique (LAAS-TEAM), IPCEI on Microelectronics - Projet Nano2022, Ce travail a été soutenu par le programme IPCEI on Microelectronics, projet Nano2022, et par la plateforme de micro et nanotechnologies du LAAS-CNRS, membre du réseau français RENATECH. Nous remercions la plateforme RENATECH de l’IEMN pour la lithographie électronique de la HSQ et le CRHEA-CNRS pour les épitaxies localisées., Université de Lille, and Renatech Network
Subjects: simulation numérique TCAD, [SPI]Engineering Sciences [physics], P-GaN, normally-off, AlGaN/GaN HEMT, EJM, épitaxie localisée
Abstract: National audience; The technology of GaN HEMT structures is the subject of major developments for large-gap power components. However, it is necessary to develop innovative technological solutions to obtain high-performance normally-off devices. We present a new normally-off structure based on a nanostructured P-GaN multi-well gate. The design of this structure, based on numerical simulations, and the technological advances for its manufacture by localised epitaxy of P-GaN wells along the grid will be presented.; RESUME-La technologie des structures HEMT GaN fait l'objet d'importants développements pour les composants de puissance grand gap. Cependant, il est nécessaire de développer des solutions technologiques innovantes pour obtenir des composants normally-off performants. Nous présentons une nouvelle structure normally-off basée sur une grille nanostructurée à multi-puits P-GaN. La conception de cette structure issue de simulations numériques ainsi que les avancées technologiques pour sa fabrication par épitaxie localisée des caissons P-GaN le long de la grille seront exposées.
Published: 2023

49. Thermoelectricity to power wireless sensors: an industrial application

Author: BOITIER, Vincent, SEGUIER, Lionel, ESTIBALS, Bruno, POTART, Patricia, MAURIN, Cédric, Laboratoire d'analyse et d'architecture des systèmes (LAAS), Université Toulouse Capitole (UT Capitole), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut National des Sciences Appliquées (INSA)-Université Toulouse - Jean Jaurès (UT2J), Université de Toulouse (UT)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT), ArcelorMittal, prestation de service, and Laboratoire d’Electrotechnique et d’Electronique de Puissance de Lille (L2EP)
Subjects: [SPI]Engineering Sciences [physics], Thermogénérateur, MPPT, Energy Harvesting, capteur sans fils, TEG, WSN, supercapacités
Abstract: National audience; With permanently high temperature gradients, a steelworks is the ideal place to install thermogenerators. The electricity recovered is stored in supercapacitors and then conditioned to power a wireless communicating sensor (a very energy-intensive lambda probe and its auxiliaries). The particularity of the project is linked to the unfavourable industrial environment (high ambient temperature > 60°C, dust deposits, slag falls, etc.), which complicates implementation and requires innovative solutions to be found.; Avec des gradients de températures élevés et permanents, une aciérie est le lieu idéal pour installer des thermogénérateurs. L'électricité récupérée est stockée dans des supercapacités puis conditionnée pour alimenter un capteur sans fil communicant (une sonde lambda très énergivore et ses auxiliaires). La particularité du projet est liée à l'environnement industriel défavorable (température ambiante élevée > 60°C, dépôt de poussières, chutes de scories, …) qui complique la mise en oeuvre et oblige à trouver des solutions adaptées innovantes.
Published: 2023

50. Méthode de préconditionnement du HEMT GaN pour une mesure reproductible de Vth

Author: Ghizzo, Lucien, Trémouilles, David, Richardeau, Frédéric, Convertisseurs Statiques (LAPLACE-CS), LAboratoire PLasma et Conversion d'Energie (LAPLACE), Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT), Équipe Intégration de Systèmes de Gestion de l'Énergie (LAAS-ISGE), Laboratoire d'analyse et d'architecture des systèmes (LAAS), Université Toulouse Capitole (UT Capitole), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut National des Sciences Appliquées (INSA)-Université Toulouse - Jean Jaurès (UT2J), Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Université Toulouse Capitole (UT Capitole), and Thales SIX GTS France
Subjects: [SPI.NRJ]Engineering Sciences [physics]/Electric power, fiabilité, [SPI.NANO]Engineering Sciences [physics]/Micro and nanotechnologies/Microelectronics, protocole de préconditionnement, variation de la tension de seuil, transistor p-GaN Schottky, piégeage
Abstract: National audience; RESUME - Dans les études de fiabilité, l'instabilité de la tension de seuil (Vth) est problématique lorsque V th est utilisé comme indicateur car elle masque une éventuelle dérive due au vieillissement réel du composant. Cette instabilité est observée lors des mesures de caractérisation électrique. Elle est liée à "l'historique de polarisation" du transistor qui peut introduire un phénomène de piégeage/dépiégeage de porteurs dans différentes couches de la structure. De nouvelles méthodes sont donc nécessaires pour surmonter ces problèmes d'instabilité liés au piégeage afin de surveiller avec précision le vieillissement des transistors en GaN. Pour résoudre le problème de répétabilité de la mesure de la tension de seuil, nous avons étudié son instabilité sur les transistors GaN. Une étape de préconditionnement appliquée juste avant la mesure réelle de Vth a été étudiée. La méthode de préconditionnement proposée est basée sur l'application d'une polarisation VGS(t) dédiée sur l'électrode de grille qui conduit à une valeur stable et répétable de Vth. Les mécanismes permettant la stabilité observée de Vth sont identifiés grâce à l'analyse de la mesure de fuite de drain après la mesure préconditionnée de Vth. La modification de la courbe de fuite démontre le rôle de l'injection de trous dans la structure. La méthode de mesure préconditionnée de Vth est proposée comme mesure complémentaire pour suivre correctement le vieillissement du p-GaN HEMT dans les futures études de fiabilité.
Published: 2023

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