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2,016 results on '"PRES Université de Toulouse"'

51. POTOMAC: towards a realistic secondary and backscattered emission model for the multipactor

Author

Plaçais, Adrien, Belhaj, Mohamed, Hillairet, Julien, Puech, Jérôme, ONERA / DPHY, Université de Toulouse [Toulouse], PRES Université de Toulouse-ONERA, Institut de Recherche sur la Fusion par confinement Magnétique (IRFM), Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Centre National d'Études Spatiales [Toulouse] (CNES), and ONERA-PRES Université de Toulouse

Subjects
SECONDARY ELECTRONS, [PHYS]Physics [physics], MULTIPACTOR, ÉLECTRONS SECONDAIRES, [SPI]Engineering Sciences [physics], ÉMISSION ÉLECTRONQIUE, MODELE PHYSIQUE, PHYSICAL MODEL, ÉLECTRONS RÉTRODIFFUSÉS, ELECTRON EMISSION, BACKSCATTERED ELECTRONS
Abstract

International audience; Characterized by a very fast growth of the electron population in vacuum of Radio-Frequency (RF) devices, the multipactor effect has been widely studied during the past decades. As it limits the transmitted RF power and may degrade RF devices, its understanding is primordial. Multipactor simulation tools give accurate results in the simplest cases, but are less accurate for advanced configurations: complex geometries, dielectric materials, presence of magnetic fields, etc. In such cases, an accurate modelling of the electron emission phenomena becomes essential. We extended a one-dimension electron emission (EE) model to three dimensions. The obtained model is compared to measured electron emission yields. The impact of this new model on the simulated multipactor threshold of parallel plane wave-guide is also investigated.

Published
2019

52. Randomised trial on clinical performances and biocompatibility of four high-flux hemodialyzers in two mode treatments: hemodialysis vs post dilution hemodiafiltration

Author

Annie Rodriguez, Anne-Marie Dupuy, Anne-Sophie Bargnoux, Marion Morena, Mouloud Bouzernidj, Jean-Paul Cristol, Lotfi Chalabi, Céline Lauret, Caroline Creput, Bruno Seigneuric, Physiologie & médecine expérimentale du Cœur et des Muscles [U 1046] (PhyMedExp), Institut National de la Santé et de la Recherche Médicale (INSERM)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS), Centre Hospitalier Régional Universitaire [Montpellier] (CHRU Montpellier), Service de Néphrologie - Immunologie Clinique [Toulouse], CHU Toulouse [Toulouse]-Hôpital de Rangueil, CHU Toulouse [Toulouse]-PRES Université de Toulouse, Centre Hospitalier Universitaire de Toulouse (CHU Toulouse)-PRES Université de Toulouse, and MORNET, Dominique

Subjects
Adult, Male, medicine.medical_specialty, Biocompatibility, medicine.medical_treatment, 030232 urology & nephrology, Urology, Ultrafiltration, lcsh:Medicine, Orosomucoid, 030204 cardiovascular system & hematology, [SDV.MHEP.UN]Life Sciences [q-bio]/Human health and pathology/Urology and Nephrology, Biochemistry, Post-dilution, Article, 03 medical and health sciences, 0302 clinical medicine, Renal Dialysis, Dialysis Solutions, medicine, Humans, Prospective Studies, lcsh:Science, Dialysis, Aged, Aged, 80 and over, Multidisciplinary, Cross-Over Studies, biology, business.industry, lcsh:R, Albumin, Middle Aged, [SDV.MHEP.UN] Life Sciences [q-bio]/Human health and pathology/Urology and Nephrology, 3. Good health, High flux, Haemodialysis, biology.protein, Kidney Failure, Chronic, lcsh:Q, Female, Hemodialysis, business, Biomarkers
Abstract

This prospective multicenter randomized comparative cross-over trial aimed at evaluating the influence of hemodialysis vs post-dilution hemodiafiltration with high-flux dialyzers in solute clearance and biocompatibility profile. 32 patients were sequentially dialyzed with Leoceed-21HX, Polypure-22S+, Rexsys-27H and VIE-21A. Primary outcome was β2-microglobulin removal. Secondary outcomes were (i) extraction of other uremic solutes (ii) parameters of inflammation and nutrition and (iii) comparative quantification of perdialytic albumin losses (using total ‘TDC’ vs partial ‘PDC’ collection of dialysate). Significant increases in removal rates of β2-microglobulin (84.7 ± 0.8 vs 71.6 ± 0.8 mg/L), myoglobin (65.9 ± 1.3 vs 38.6 ± 1.3 µg/L), free immunoglobulin light chains Kappa (74.9 ± 0.8 vs 55.6 ± 0.8 mg/L), β-trace protein (54.8 ± 1.3 vs 26.8 ± 1.4 mg/L) and orosomucoid (11.0 ± 1.1 vs 6.0 ± 1.1 g/L) but not myostatin (14.8 ± 1.5 vs 13.0 ± 1.5 ng/mL) were observed in HDF compared to HD when pooling all dialyzers. Rexsys and VIE-A use in both HD and HDF subgroups was associated to a better removal of middle/large-size molecules compared to Leoceed and Polypure, except β2-microglobulin for Rexsys. Inflammatory parameters were unchanged between dialyzers without any interaction with dialysis modality. Mean dialysate albumin loss was comparable between TDC and PDC (1.855 vs 1.826 g/session for TDC and PDC respectively). In addition, a significant difference in albumin loss was observed between dialyzers with the highest value (4.5 g/session) observed using Rexsys. Use of all dialyzers was associated with good removals of the large spectrum of uremic toxins tested and good biocompatibility profiles, with an additional gain in removal performances with HDF. Larger surface area, thinner wall and resultant very high ultrafiltration coefficient of Rexsys should be taken into account in its clear performance advantages.

Published
2019
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53. The non-linear sewing lemma I : weak formulation

Author

Antoine Lejay, Antoine Brault, Institut de Mathématiques de Toulouse UMR5219 (IMT), 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), Mathématiques Appliquées Paris 5 (MAP5 - UMR 8145), Université Paris Descartes - Paris 5 (UPD5)-Institut National des Sciences Mathématiques et de leurs Interactions (INSMI)-Centre National de la Recherche Scientifique (CNRS), TO Simulate and CAlibrate stochastic models (TOSCA), Inria Sophia Antipolis - Méditerranée (CRISAM), Institut National de Recherche en Informatique et en Automatique (Inria)-Institut National de Recherche en Informatique et en Automatique (Inria)-Institut Élie Cartan de Lorraine (IECL), Université de Lorraine (UL)-Centre National de la Recherche Scientifique (CNRS)-Université de Lorraine (UL)-Centre National de la Recherche Scientifique (CNRS), Institut Élie Cartan de Lorraine (IECL), Université de Lorraine (UL)-Centre National de la Recherche Scientifique (CNRS), The authors are grateful to the CIRM (Marseille, France) for its kind hospitality with the Research-in-Pair program., 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 des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Université Toulouse 1 Capitole (UT1)-Université Toulouse - Jean Jaurès (UT2J)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS), Centre National de la Recherche Scientifique (CNRS)-Institut National des Sciences Mathématiques et de leurs Interactions (INSMI)-Université Paris Descartes - Paris 5 (UPD5), Institut de Mathématiques de Toulouse UMR5219 ( IMT ), Université Toulouse 1 Capitole ( UT1 ) -Université Toulouse - Jean Jaurès ( UT2J ) -Université Toulouse III - Paul Sabatier ( UPS ), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-PRES Université de Toulouse-Institut National des Sciences Appliquées - Toulouse ( INSA Toulouse ), Institut National des Sciences Appliquées ( INSA ) -Institut National des Sciences Appliquées ( INSA ) -Centre National de la Recherche Scientifique ( CNRS ), TO Simulate and CAlibrate stochastic models ( TOSCA ), Inria Sophia Antipolis - Méditerranée ( CRISAM ), Institut National de Recherche en Informatique et en Automatique ( Inria ) -Institut National de Recherche en Informatique et en Automatique ( Inria ) -Institut Élie Cartan de Lorraine ( IECL ), Université de Lorraine ( UL ) -Centre National de la Recherche Scientifique ( CNRS ) -Université de Lorraine ( UL ) -Centre National de la Recherche Scientifique ( CNRS ), Institut Élie Cartan de Lorraine ( IECL ), Université de Lorraine ( UL ) -Centre National de la Recherche Scientifique ( CNRS ), Université Toulouse 1 Capitole (UT1)-Université Toulouse - Jean Jaurès (UT2J)-Université Toulouse III - Paul Sabatier (UPS), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-PRES Université de Toulouse-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), and Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Statistics and Probability, MSC (2010) : 60H10, 54C65, sewing lemma, [ MATH.MATH-CA ] Mathematics [math]/Classical Analysis and ODEs [math.CA], Differential equation, Existential quantification, non uniqueness of solutions, Perturbation (astronomy), [MATH.MATH-CA]Mathematics [math]/Classical Analysis and ODEs [math.CA], Weak formulation, 01 natural sciences, 010104 statistics & probability, FOS: Mathematics, Applied mathematics, measurable flows, 0101 mathematics, rough differential equations, rough paths, Mathematics, flow approximations, Lemma (mathematics), Probability (math.PR), 010102 general mathematics, Multiplicative function, Lipschitz flows, 16. Peace & justice, Lipschitz continuity, [MATH.MATH-PR]Mathematics [math]/Probability [math.PR], Nonlinear system, 60H10, Statistics, Probability and Uncertainty, [ MATH.MATH-PR ] Mathematics [math]/Probability [math.PR], Mathematics - Probability
Abstract

We introduce a new framework to deal with rough differential equations based on flows and their approximations. Our main result is to prove that measurable flows exist under weak conditions, even solutions to the corresponding rough differential equations are not unique. We show that under additional conditions of the approximation, there exists a unique Lipschitz flow. Then, a perturbation formula is given. Finally, we link our approach to the additive, multiplicative sewing lemmas and the rough Euler scheme., Electronic Journal of Probability, Institute of Mathematical Statistics (IMS), In press

Published
2019
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54. Internal Charging Analysis of a Space Instrument in PEO With a Dedicated Modeling Chain

Author

B. Jeanty-Ruard, P. Sarrailh, D. Payan, A. Trouche, N. Chabalier, A. Champlain, G. Santin, J. Forest, Artenum, ONERA / DPHY, Université de Toulouse [Toulouse], ONERA-PRES Université de Toulouse, Centre National d'Études Spatiales [Toulouse] (CNES), European Space Research and Technology Centre (ESTEC), European Space Agency (ESA), Artenum, Paris, and PRES Université de Toulouse-ONERA

Subjects
Nuclear and High Energy Physics, Monte Carlo method, MULTISCALE, Solid modeling, 01 natural sciences, 010305 fluids & plasmas, Front and back ends, [SPI]Engineering Sciences [physics], Software, DOSE, Electric field, MONTE CARLO, GRAS, 0103 physical sciences, JASON-3, Aerospace engineering, MODELING CHAIN, EXTENDED GDML EDITOR (EDGE), GEANT4, Physics, ACTIVE MEASUREMENT BOX OF ELECTROSTATIC RISK (AMBER) INSTRUMENT, [PHYS]Physics [physics], Earth's orbit, Spacecraft, business.industry, Plasma, Condensed Matter Physics, [PHYS.PHYS.PHYS-SPACE-PH]Physics [physics]/Physics [physics]/Space Physics [physics.space-ph], INTERNAL CHARGING (IC), MODELLING OF RADIATION (MOORA), SIMULATION, SPACECRAFT PLASMA INTERACTION SOFTWARE (SPIS)-IC, COMPUTER-AIDED DESIGN (CAD), RADIATION, business, CHARGE
Abstract

International audience; An internal charging (IC) analysis of the active measurement box of electrostatic risk (AMBER) instrument onboard Jason-3 in polar earth orbit (PEO) has been performed with a new dedicated modeling chain. The ExtendeD Gdml Editor (EDGE) application is in charge of the definition of the computer-aided design (CAD) model. The Modelling Of Radiation (MoORa) front end helps to configure, control, and postprocess the ESA/GRAS Monte Carlo simulation based on Geant4 to model the transport of space radiation environment. Finally, using the radiation results, the IC analysis, including internal electric fields and risk of discharge, is performed with the Spacecraft Plasma Interaction Software (SPIS)-IC 3-D time-dependent simulation code.

Published
2019
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55. Existence of strong solutions to a fluid–structure system with a structure given by a finite number of parameters

Author

Guillaume Delay, Institut de Mathématiques de Toulouse UMR5219 (IMT), Université Toulouse 1 Capitole (UT1)-Université Toulouse - Jean Jaurès (UT2J)-Université Toulouse III - Paul Sabatier (UPS), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-PRES Université de Toulouse-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-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 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 National de la Recherche Scientifique (CNRS)-PRES Université de Toulouse-Université Toulouse III - Paul Sabatier (UPS), and Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Université Toulouse - Jean Jaurès (UT2J)-Université Toulouse 1 Capitole (UT1)

Subjects
Numerical Analysis, Applied Mathematics, 010102 general mathematics, Mathematical analysis, 01 natural sciences, 010101 applied mathematics, Physics::Fluid Dynamics, Computational Mathematics, MSC numbers: 74F10, 74H20, 74H25, 74H30, 76D03, Flow velocity, Modeling and Simulation, Fluid–structure interaction, Compressibility, [MATH.MATH-AP]Mathematics [math]/Analysis of PDEs [math.AP], Virtual work, Boundary value problem, 0101 mathematics, [MATH]Mathematics [math], Navier–Stokes equations, Finite set, Analysis, Mathematics, Wind tunnel
Abstract

We study the existence of strong solutions to a 2d fluid–structure system. The fluid is modelled by the incompressible Navier–Stokes equations. The structure represents a steering gear and is described by a finite number of parameters and its equations are derived from a virtual work principle. The global domain represents a wind tunnel and imposes mixed boundary conditions to the fluid velocity. Our method reposes on the analysis of the linearized system. Under compatibility conditions on the initial conditions, we can guarantee local existence in time of strong solutions to the fluid–structure problem. MSC numbers: 74F10, 74H20, 74H25, 74H30, 76D03.

Published
2019
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56. On the accuracy in high dimensional linear models under imperfect linkage disequilibrium

Author

Rabier , Charles-Elie, Grusea , Simona, Institut des Sciences de l'Evolution de Montpellier (UMR ISEM), Centre de Coopération Internationale en Recherche Agronomique pour le Développement (CIRAD)-École pratique des hautes études (EPHE)-Université de Montpellier (UM)-Institut de recherche pour le développement [IRD] : UR226-Centre National de la Recherche Scientifique (CNRS), Laboratoire d'Informatique de Robotique et de Microélectronique de Montpellier (LIRMM), Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS), Institut de Mathématiques de Toulouse UMR5219 (IMT), Centre National de la Recherche Scientifique (CNRS)-PRES Université de Toulouse-Université Toulouse III - Paul Sabatier (UPS), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Université Toulouse - Jean Jaurès (UT2J)-Université Toulouse 1 Capitole (UT1), Institut des Sciences de l'Evolution de Montpellier ( UMR ISEM ), Centre de Coopération Internationale en Recherche Agronomique pour le Développement ( CIRAD ) -Université de Montpellier ( UM ) -Institut de recherche pour le développement [IRD] : UR226-Centre National de la Recherche Scientifique ( CNRS ), Laboratoire d'Informatique de Robotique et de Microélectronique de Montpellier ( LIRMM ), Université de Montpellier ( UM ) -Centre National de la Recherche Scientifique ( CNRS ), Institut de Mathématiques de Toulouse UMR5219 ( IMT ), Université Toulouse 1 Capitole ( UT1 ) -Université Toulouse - Jean Jaurès ( UT2J ) -Université Toulouse III - Paul Sabatier ( UPS ), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-PRES Université de Toulouse-Institut National des Sciences Appliquées - Toulouse ( INSA Toulouse ), and Institut National des Sciences Appliquées ( INSA ) -Institut National des Sciences Appliquées ( INSA ) -Centre National de la Recherche Scientifique ( CNRS )

Subjects
Genomic Selection, Ridge Regression, [MATH.MATH-ST]Mathematics [math]/Statistics [math.ST], Linear Model, [ MATH.MATH-ST ] Mathematics [math]/Statistics [math.ST], Singular Value Decomposition, Prediction, Sparsity, Accuracy, High Dimension
Abstract

Genomic selection (GS) consists in predicting breeding values of selection candidates, using a large number of genetic markers. An important question in GS is the determination of the number of markers required for a good prediction. Many studies show that it becomes useless to consider too many markers. In contrast, for some species, the number of markers remains too small to cover the huge genome size. Under such sparse genetic map, it is likely to observe some imperfect linkage disequilibrium: the alleles at a gene location and at a marker located nearby vary. In this context, we tackle here the problem of imperfect linkage disequilibrium in the Ridge regression framework. We present theoretical results regarding the accuracy criteria, i.e., the correlation between predicted value and true value. We show the influence of the projection of the causal regression function (i.e. at genes) on the space spanned by the columns of the design matrix (i.e. at markers). Asymptotic results, in a high dimensional framework, are given, and we prove that the convergence to an optimal accuracy depends on a few limiting factors. This study generalizes our recent results (Rabier et al. (2018)) obtained under perfect linkage disequi-librium. Last, illustrations on simulated and real data are proposed.

Published
2019

57. Validation of Internal Charging Tools With Experiments in REEF

Author

Pierre Sarrailh, D. Rodgers, Thierry Paulmier, Keith Ryden, Denis Payan, Alex Hands, Remi Pacaud, Surrey Space Centre [Guildford], University of Surrey (UNIS), ONERA / DPHY, Université de Toulouse [Toulouse], ONERA-PRES Université de Toulouse, Centre National d'Études Spatiales [Toulouse] (CNES), European Space Research and Technology Centre (ESTEC), European Space Agency (ESA), and PRES Université de Toulouse-ONERA

Subjects
[PHYS]Physics [physics], Nuclear and High Energy Physics, geography, geography.geographical_feature_category, ESSAI RADIATION SOL, Computer science, media_common.quotation_subject, Fidelity, ELECTROSTATIC DISCHARGE (ESD), Condensed Matter Physics, 01 natural sciences, 010305 fluids & plasmas, [SPI]Engineering Sciences [physics], 13. Climate action, 0103 physical sciences, INTERNAL CHARGING, CHARGE INTERNE, DECHARGE ELECTROSTATIQUE, Reef, GROUND RADIATION TESTING, media_common, Space environment, Marine engineering
Abstract

International audience; The objective of the European Space Agency validation of internal charging tools using the realistic electron environmental facility (REEF) project is to assess the performance of internal charging tools against experimental measurements made at the REEF facility at the University of Surrey. REEF uses an intense strontium-90 beta-emitting radioactive source to simulate the space environment. This project is complemented by parallel experiments to derive material parameters, conducted by ONERA. We report results from REEF with four different types of dielectric material and compare these results to predictions from the DICTAT, MCICT, and NUMIT internal charging simulation tools. The materials under investigation are Cirlex, PEEK, FR4, and Neoflon (FEP). We find that in many cases, the computer codes struggle to recreate REEF results, which raises significant questions over the validity of internal charging mitigation analyses. We show the advantages and disadvantages of each model and suggest what features could be added in order to improve the fidelity of their predictions.

Published
2019
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58. Modeling of combined effects of surface roughness and blowing for Reynolds-averaged Navier–Stokes turbulence models

Author

M. Olazabal Loumé, Y. Marchenay, F. Chedevergne, ONERA / DMPE, Université de Toulouse [Toulouse], PRES Université de Toulouse-ONERA, CEA-CESTA (Le Barp, Gironde), and ONERA-PRES Université de Toulouse

Subjects
Computational Mechanics, 02 engineering and technology, Surface finish, Turbulence theory and modelling, 01 natural sciences, Law of the wall, 010305 fluids & plasmas, Physics::Fluid Dynamics, [SPI]Engineering Sciences [physics], Flow velocity, 0203 mechanical engineering, Parasitic drag, 0103 physical sciences, Fluid dynamics, Surface roughness, Fluid mechanics, Turbulent flows, Boundary value problem, [PHYS]Physics [physics], Fluid Flow and Transfer Processes, Physics, Boundary layer flow, Turbulence, Mechanical Engineering, Mechanics, Condensed Matter Physics, Fluid drag, Navier Stokes equations, 020303 mechanical engineering & transports, Mechanics of Materials, Reynolds-averaged Navier–Stokes equations
Abstract

International audience; A new modeling strategy adapted to Reynolds-Averaged Navier-Stokes (RANS) turbulence models is proposed to predict combined effects of roughness and blowing boundary conditions. First, an analysis of experimental data is presented, leading to a specific description of the velocity profile in the logarithmic region of transpired turbulent boundary layers over rough walls. This analysis points out the deficiencies of existing roughness corrections to predict the effect of blowing in the presence of surface roughness. Indeed, these corrections tend to underestimate skin friction coefficients and Stanton numbers with addition of blowing. The failure of existing models derives from an inaccurate estimation of the velocity shift of the logarithmic law given by roughness corrections. Concretely, roughness corrections underestimate the apparent velocity shift of the logarithmic law with blowing. To recover the expected law of the wall, an additional contribution on the velocity shift, characterizing blowing/roughness interactions, is integrated to standard roughness corrections. To that end, a modification of the equivalent sand grain height, adapted to k − ω based turbulence models, is proposed to take blowing effects into account. Furthermore, an extension of Aupoix's thermal correction [B. Aupoix, International Journal of Heat and Fluid Flow 56, 160 (2015)] to blowing is presented to predict combined thermal effects of roughness and blowing. The assessment of the proposed corrections is performed using k − ω Shear Stress Transport (SST) model on a large set of experimental data and proves the relevance of the strategy for incompressible and compressible turbulent boundary layers.

Published
2021
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59. Une approche opérationnelle pour la prédiction de la dynamique des ceintures de radiations terrestres

Author

Bernoux Guillerme, Brunet Antoine, Buchlin Éric, Janvier Miho, Sicard Angélica, ONERA / DPHY, Université de Toulouse [Toulouse], ONERA-PRES Université de Toulouse, Institut d'astrophysique spatiale (IAS), Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), Funding from Region Occitanie and ONERA, under Grant Agreements 587 19008721/ALDOCT and 30196, and PRES Université de Toulouse-ONERA

Subjects
Atmospheric Science, Space weather, Apprentissage statistique, 010504 meteorology & atmospheric sciences, Solar wind, Prévision, 01 natural sciences, Vent solaire, [SPI]Engineering Sciences [physics], symbols.namesake, Météorologie de l'espace, Meteorology. Climatology, Machine learning, 0103 physical sciences, Operational approach, 010303 astronomy & astrophysics, 0105 earth and related environmental sciences, [PHYS]Physics [physics], Ceinture de radiations, Geophysics, Radiation belts, Space and Planetary Science, Van Allen radiation belt, symbols, Earth (chemistry), QC851-999, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], Geology, Forecasting
Abstract

Accepted manuscript; International audience; The Ca index is a time-integrated geomagnetic index that correlates well with the dynamics of high-energy electron fluxes in the outer radiation belts. Therefore Ca can be used as an indicator for the state of filling of the radiation belts for those electrons. Ca also has the advantage of being a ground-based measurement with extensive historical records. In this work, we propose a data-driven model to forecast Ca up to 24 hours in advance from near-Earth solar wind parameters. Our model relies mainly on a recurrent neural network architecture called Long Short Term Memory that has shown good performances in forecasting other geomagnetic indices in previous papers. Most implementation choices in this study were arbitrated from the point of view of a space system operator, including the data selection and split, the definition of a binary classification threshold, and the evaluation methodology. We evaluate our model (against a linear baseline) using both classical and novel (in the space weather field) measures. In particular, we use the Temporal Distortion Mix (TDM) to assess the propensity of two time series to exhibit time lags. We also evaluate the ability of our model to detect storm onsets during quiet periods. It is shown that our model has high overall accuracy, with evaluation measures deteriorating in a smooth and slow trend over time. However, using the TDM and binary classification forecast evaluation metrics, we show that the forecasts lose some of their usefulness in an operational context even for time horizons shorter than 6 hours. This behaviour was not observable when evaluating the model only with metrics such as the root-mean-square error or the Pearson linear correlation. Considering the physics of the problem, this result is not surprising and suggests that the use of more spatially remote data (such as solar imaging) could improve space weather forecasts.; L'indice Ca est un indice géomagnétique intégré dans le temps qui présente une bonne corrélation avec la dynamique des flux d'électrons de haute énergie dans les ceintures de radiation extérieures. Par conséquent, Ca peut être utilisé comme un indicateur de l'état de remplissage des ceintures de radiation pour ces électrons. Ca a également l'avantage d'être une mesure faite au sol possédant un historique important. Dans cette étude, nous proposons un modèle dirigé par les données pour prévoir Ca jusqu'à 24 heures à l'avance à partir des paramètres du vent solaire mesurés proche de la Terre. Notre modèle s'appuie principalement sur un réseau de neurones récurrent appelé réseau de mémoire à long et à court terme (LSTM) qui a montré de bonnes performances dans la prévision d'autres indices géomagnétiques dans des articles précédents. La plupart des choix d'implémentation dans cette étude ont été arbitrés du point de vue d'un opérateur de systèmes spatiaux, y compris la sélection et la séparation des données, la définition d'un seuil de classification binaire et la méthodologie d'évaluation. Nous évaluons notre modèle (par rapport à un modèle de base linéaire) en utilisant des métriques classiques et des métriques nouvelles (dans le domaine de la météorologie spatiale). En particulier, nous utilisons le Temporal Distortion Mix (TDM) pour évaluer la propension de deux séries temporelles à présenter des décalages temporels. Nous évaluons également la capacité de notre modèle à détecter le début des tempêtes pendant les périodes calmes. Nous montrons que notre modèle a une précision globale élevée, avec des mesures d'évaluation qui se détériorent de manière régulière et lente dans le temps. Cependant, en utilisant le TDM et les mesures d'évaluation de la prévision par classification binaire, nous montrons que les prévisions perdent une partie de leur utilité dans un contexte opérationnel, même pour des horizons temporels inférieurs à 6 heures. Ce comportement n'était pas observable lorsque le modèle était évalué uniquement avec des mesures telles que l'erreur quadratique moyenne ou la corrélation linéaire de Pearson. Compte tenu de la physique du problème, ce résultat n'est pas surprenant et suggère que l'utilisation de données plus éloignées dans l'espace (comme l'imagerie solaire) pourrait améliorer les prévisions relevant de la météorologie de l'espace.

Published
2021
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60. Circuit design using Schmitt Trigger to reliability improvement

Author

Fernanda Lima Kastensmidt, Alexandra L. Zimpeck, Cristina Meinhardt, Laurent Artola, Ricardo Reis, Guillaume Hubert, Instituto de Informática, Programa de Pós-Graduação em Computação [Porto Alegre] (PPGC), Universidade Federal do Rio Grande do Sul [Porto Alegre] (UFRGS), Universidade Federal de Santa Catarina = Federal University of Santa Catarina [Florianópolis] (UFSC), ONERA / DPHY, Université de Toulouse [Toulouse], PRES Université de Toulouse-ONERA, and ONERA-PRES Université de Toulouse

Subjects
Computer science, Circuit design, Logic circuit, Hardware_PERFORMANCEANDRELIABILITY, 02 engineering and technology, Design strategy, 01 natural sciences, law.invention, [SPI]Engineering Sciences [physics], law, Schmitt trigger, Control theory, 0103 physical sciences, Hardware_INTEGRATEDCIRCUITS, 0202 electrical engineering, electronic engineering, information engineering, Electrical and Electronic Engineering, Schmitt Trigger, Safety, Risk, Reliability and Quality, Electronic circuit, [PHYS]Physics [physics], 010302 applied physics, FinFET technology, 020208 electrical & electronic engineering, Transistor, Condensed Matter Physics, Atomic and Molecular Physics, and Optics, Surfaces, Coatings and Films, Electronic, Optical and Magnetic Materials, Soft error, Logic gate, Decoupling (electronics), Hardware_LOGICDESIGN
Abstract

International audience; This paper presents a design strategy to reduce the impact of process variations and soft error susceptibility in FinFET circuits. The mitigation is provided by connecting a Schmitt Trigger at the logic gate output. The improvements in power and delay variability can reach up to 32.6% and 42.1%, respectively, with logic cells almost immune to soft error even at the near-threshold regime. When compared with other circuit-level methods such as sleep transistor, decoupling cells, and transistor reordering, on average, the Schmitt Trigger technique is at least 6%, 8%, and 10.5% more robust to process variability, respectively.

Published
2020
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61. Gaussian process metamodeling of functional-input code for coastal flood hazard assessment

Author

Jeremy Rohmer, José Betancourt, Thierry Klein, Déborah Idier, Rodrigo Pedreros, François Bachoc, Institut de Mathématiques de Toulouse UMR5219 (IMT), 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), Ecole Nationale de l'Aviation Civile (ENAC), Bureau de Recherches Géologiques et Minières (BRGM) (BRGM), Agence Nationale de la Recherche, ANR-16-CE04-0011,RISCOPE,Système d'alerte de submersion côtière centré sur le risque(2016), 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 National de la Recherche Scientifique (CNRS)-PRES Université de Toulouse-Université Toulouse III - Paul Sabatier (UPS), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Université Toulouse - Jean Jaurès (UT2J)-Université Toulouse 1 Capitole (UT1), Université Toulouse 1 Capitole (UT1)-Université Toulouse - Jean Jaurès (UT2J)-Université Toulouse III - Paul Sabatier (UPS), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-PRES Université de Toulouse-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), and Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Mathematical optimization, Computer science, Gaussian, Computer experiments, 0211 other engineering and technologies, Gaussian processes, [SDU.STU]Sciences of the Universe [physics]/Earth Sciences, 02 engineering and technology, Metamodeling, Industrial and Manufacturing Engineering, symbols.namesake, [STAT.ML]Statistics [stat]/Machine Learning [stat.ML], [MATH.MATH-ST]Mathematics [math]/Statistics [math.ST], Robustness (computer science), Gaussian process, Safety, Risk, Reliability and Quality, Projection (set theory), 021110 strategic, defence & security studies, 021103 operations research, [SDE.IE]Environmental Sciences/Environmental Engineering, Dimensionality reduction, Model selection, Computer experiment, Functional inputs, [MATH.MATH-PR]Mathematics [math]/Probability [math.PR], [SDE]Environmental Sciences, symbols, Computer code experiments
Abstract

International audience; This paper investigates the construction of a metamodel for coastal flooding early warning at the peninsula of Gâvres, France. The code under study is an hydrodynamic model which receives time-varying maritime conditions as inputs. We concentrate on Gaussian pocess metamodels to emulate the behavior of the code. To model the inputs we make a projection of them onto a space of lower dimension. This setting gives rise to a model selection methodology which we use to calibrate four characteristics of our functional-input metamodel: (i) the family of basis functions to project the inputs; (ii) the projection dimension; (iii) the distance to measure similarity between functional input points; and (iv) the set of functional predictors to keep active. The proposed methodology seeks to optimize these parameters for metamodel predictability, at an affordable computational cost. A comparison to a dimensionality reduction approach based on the projection error of the input functions only showed that the latter may lead to unnecessarily large projection dimensions. We also assessed the adaptability of our methodology to changes in the number of training and validation points. The methodology proved its robustness by finding the optimal solution for most of the instances, while being computationally efficient.

Published
2020
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62. Satellite Attitude Control with a six-Control Moment Gyro Cluster tested under Microgravity Conditions

Author

Evain, Hélène, Alazard, Daniel, Rognant, Mathieu, Solatges, Thomas, Brunet, Antoine, Mignot, Jean, Rodriguez, Nicolas, Dias-Ribeiro, Adrien, Centre National d'Études Spatiales [Toulouse] (CNES), Département Conception et conduite des véhicules Aéronautiques et Spatiaux (DCAS), Institut Supérieur de l'Aéronautique et de l'Espace (ISAE-SUPAERO), ONERA / DTIS, Université de Toulouse [Toulouse], ONERA-PRES Université de Toulouse, Société d'innovations technologiques et industrielles avancées - SITIA (FRANCE), ONERA / DPHY, Université de Toulouse [Toulouse], PRES Université de Toulouse-ONERA, Centre National d'Études Spatiales - CNES (FRANCE), Institut Supérieur de l'Aéronautique et de l'Espace - ISAE-SUPAERO (FRANCE), Office National d'Etudes et Recherches Aérospatiales - ONERA (FRANCE), and Département Conception et conduite des véhicules Aéronautiques et Spatiaux - DCAS (Toulouse, France)

Subjects
[SPI.OTHER]Engineering Sciences [physics]/Other, Autre, Attitude control, Microgravity, Singularit, Control moment gyros
Abstract

International audience; The attitude control of a satellite equipped with a six-Control Moment Gyro (CMG) cluster is studied, taking into account CMG failure cases and constraints like actuator saturation and real-time aspects. The design of the steering law that allocates the required torques among the actuators is made complex by singularities (gimbal angles of the CMGs where no torque can be created along an axis). This paper describes the problem of a constrained allocation applied to the CMG system, and explains the selected solution. An experimental setup with six CMGs has been designed. It calculates in real-time the attitude guidance laws and control loop. Agile manoeuvres simulating nanosatellite attitude reorientations have been successfully carried out during a European Space Agency (ESA) parabolic flight campaign. The results show that the steering law performs as expected even in case of CMG failures.

Published
2019

63. Evaluation of Electron-emitting Film for Spacecraft Charging Mitigation (ELFs Charm)

Author

Sarah Dadouch, Minoru Iwata, Kenji Sakamoto, Teppei Okumura, Kazuhiro Toyoda, Jean-Charles Mateo Velez, Atomu Tanaka, Mengu Cho, Graduate School of Life Science and Systems Engineering, ONERA / DPHY, Université de Toulouse [Toulouse], ONERA-PRES Université de Toulouse, Japan Aerospace Exploration Agency [Tsukuba] (JAXA), and PRES Université de Toulouse-ONERA

Subjects
Astrophysics::High Energy Astrophysical Phenomena, ESD, 02 engineering and technology, Electron, MITIGATION, PHÉNOMÈNE DE CHARGE, 01 natural sciences, 7. Clean energy, MITIGATION TECHNOLOGY, 010305 fluids & plasmas, Spacecraft charging, [SPI]Engineering Sciences [physics], 0203 mechanical engineering, 0103 physical sciences, Charm (quantum number), Aerospace engineering, [PHYS]Physics [physics], 020301 aerospace & aeronautics, Thesaurus (information retrieval), business.industry, ELF, Physics::Space Physics, Environmental science, SPACECRAFT CHARGING, business, DECHARGE ELECTROSTATIQUE
Abstract

To protect the satellite from the accidents due to spacecraft charging, Kyushu Institute of Technology (Kyutech) is developing a device called ELFs-Charm, which stands for ELectron-emitting Film for Spacecraft CHARging Mitigation. ELFs-Charm was mounted on HORYU-II, which was launched to a Polar Earth Orbit in May 2012. From the orbital data, the emitter’s soundness and working principles were confirmed. As a next step, we are considering the practical operation for mitigation of spacecraft charging. The present emission level was not enough to increase the satellite potential. Theoretically, if the emitter can emit more electrons than the incoming electrons, it can increase the satellite potential during the sub-storm. We focus our efforts on improving two parameters. One is the potential difference of the emitter surface. Another one is the threshold voltage of electron emission. A potential difference of the emitter surface depends on the insulator charging capacity due to the secondary electron emissions with each energy gap between the satellite potential and the primary electron energy. The threshold voltage depends on the shape of emitter. We can improve the ELFs-charm emission performance by measurement of these two parameters in ONERA Space Environment vacuum chamber and Kyutech Space Environment chamber. In this paper, we describe the two parameters of several samples and how the performance was improved., The 31st International Symposium on Space Technology and Science (31st ISTS), June 3-9, 2017, Matsuyama, Japan

Published
2019
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64. Co-design of aircraft vertical tail and control laws using distributed electric propulsion

Author

E. Nguyen Van, C. Döll, Philippe Pastor, Daniel Alazard, André, Cécile, Département Conception et conduite des véhicules Aéronautiques et Spatiaux (DCAS), Institut Supérieur de l'Aéronautique et de l'Espace (ISAE-SUPAERO), ONERA / DTIS, Université de Toulouse [Toulouse], PRES Université de Toulouse-ONERA, ONERA-PRES Université de Toulouse, Institut Supérieur de l'Aéronautique et de l'Espace - ISAE-SUPAERO (FRANCE), and Office National d'Etudes et Recherches Aérospatiales - ONERA (FRANCE)

Subjects
Co-design, 0209 industrial biotechnology, ACTIONNEUR, DIMENSIONNEMENT, Distributed Electric Propulsion, [SPI] Engineering Sciences [physics], 02 engineering and technology, [MATH] Mathematics [math], BANDE PASSANTE, [INFO] Computer Science [cs], actuator bandwidth, [SPI.AUTO]Engineering Sciences [physics]/Automatic, [PHYS] Physics [physics], COMMANDE STRUCTURE, [SPI]Engineering Sciences [physics], 020901 industrial engineering & automation, DIFFERENTIAL THRUST, 0202 electrical engineering, electronic engineering, information engineering, Hinfini CONTROL, CO-DESIGN, [INFO]Computer Science [cs], [MATH]Mathematics [math], EMPENNAGE VERTICAL, Automatique / Robotique, ACTUATOR BANDWIDTH, VERTICAL TAIL SIZING, PROPULSION ÉLECTRIQUE DISTRIBUÉE, Physics, [PHYS]Physics [physics], POUSSÉE DIFFÉRENTIELLE, $H_\infty$ control, 020208 electrical & electronic engineering, Bandwidth (signal processing), Differential Thrust, Sizing, Electrically powered spacecraft propulsion, Control and Systems Engineering, Law, vertical tail sizing, Actuator, Control methods, DISTRIBUTED ELECTRIC PROPULSION
Abstract

International audience; Distributed Electric Propulsion is investigated as a way to increase directional control of aircraft and reduce the vertical tail surface area. A co-design approach is presented where a $H_\infty$ control method is used to both synthesize longitudinal/lateral control law gains and allocation module while sizing the vertical tail surface area and the propeller actuator bandwidth. The variation of the vertical tail surface area is captured throughout a collection of linearised aircraft systems representing different sizes of the vertical tail reassembled in a Linear Fractional Representation. This approach allows a reduction of $60\%$ of the vertical tail surface area while maintaining desired dynamic behaviors with low actuator bandwidth.\end{abstract}

Published
2019

65. Concentration inequalities for Stochastic Differential Equations with additive fractional noise

Author

Maylis Varvenne, 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 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), Centre National de la Recherche Scientifique (CNRS)-PRES Université de Toulouse-Université Toulouse III - Paul Sabatier (UPS), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Université Toulouse - Jean Jaurès (UT2J)-Université Toulouse 1 Capitole (UT1), Institut de Mathématiques de Toulouse UMR5219 ( IMT ), Université Toulouse 1 Capitole ( UT1 ) -Université Toulouse - Jean Jaurès ( UT2J ) -Université Toulouse III - Paul Sabatier ( UPS ), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-PRES Université de Toulouse-Institut National des Sciences Appliquées - Toulouse ( INSA Toulouse ), and Institut National des Sciences Appliquées ( INSA ) -Institut National des Sciences Appliquées ( INSA ) -Centre National de la Recherche Scientifique ( CNRS )

Subjects
Statistics and Probability, fractional Brownian motion, Interval (mathematics), 01 natural sciences, Noise (electronics), 010104 statistics & probability, Stochastic differential equation, Mathematics::Probability, FOS: Mathematics, Applied mathematics, 60G22, 0101 mathematics, Mathematics, Hurst exponent, Fractional Brownian motion, 010102 general mathematics, Probability (math.PR), [MATH.MATH-PR]Mathematics [math]/Probability [math.PR], Stochastic Differential Equations, concentration inequalities, occupation measures, 60H10, Statistics, Probability and Uncertainty, 60E15, [ MATH.MATH-PR ] Mathematics [math]/Probability [math.PR], Mathematics - Probability
Abstract

In this paper, we establish concentration inequalities both for functionals of the whole solution on an interval [0, T ] of an additive SDE driven by a fractional Brownian motion with Hurst parameter H $\in$ (0, 1) and for functionals of discrete-time observations of this process. Then, we apply this general result to specific functionals related to discrete and continuous-time occupation measures of the process., Comment: Electronic Journal of Probability, Institute of Mathematical Statistics (IMS), In press

Published
2019

66. EQUILATERAL TRIANGLE SKEW CONDITION FOR QUASICONFORMALITY

Author

Peter Haïssinsky, Colleen Ackermann, Aimo Hinkkanen, Department of Mathematics [Urbana], University of Illinois at Urbana-Champaign [Urbana], University of Illinois System-University of Illinois System, Institut de Mathématiques de Marseille (I2M), Aix Marseille Université (AMU)-École Centrale de Marseille (ECM)-Centre National de la Recherche Scientifique (CNRS), Institut de Mathématiques de Toulouse UMR5219 (IMT), 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), ANR-12-BS01-0003,GDSous/GSG,Géométrie Des Sous-groupes(2012), ANR-13-BS01-0002,LAMBDA,Espaces de paramètres en dynamique holomorphe.(2013), Department of Mathematics [Urbana-Champaign], Institut de Mathématiques de Marseille ( I2M ), Aix Marseille Université ( AMU ) -Ecole Centrale de Marseille ( ECM ) -Centre National de la Recherche Scientifique ( CNRS ), Picard, Institut de Mathématiques de Toulouse UMR5219 ( IMT ), 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 ) -PRES Université de Toulouse-Université Paul Sabatier - Toulouse 3 ( UPS ) -Université Toulouse - Jean Jaurès ( UT2J ) -Université Toulouse 1 Capitole ( UT1 ) -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 ) -PRES Université de Toulouse-Université Paul Sabatier - Toulouse 3 ( UPS ) -Université Toulouse - Jean Jaurès ( UT2J ) -Université Toulouse 1 Capitole ( UT1 ), ANR-12-BS01-0003,GDSous/GSG,Géométrie Des Sous-groupes ( 2012 ), ANR-13-BS01-0002 ,LAMBDA, 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
[ MATH.MATH-CV ] Mathematics [math]/Complex Variables [math.CV], Mathematics::Dynamical Systems, Mathematics - Complex Variables, Mathematics::Complex Variables, General Mathematics, 010102 general mathematics, Skew, [MATH.MATH-CV]Mathematics [math]/Complex Variables [math.CV], Computer Science::Computational Geometry, 16. Peace & justice, Equilateral triangle, 01 natural sciences, Computer Science::Computers and Society, Combinatorics, Distortion (mathematics), Physics::Popular Physics, Computer Science::Graphics, 0103 physical sciences, FOS: Mathematics, Mathematics::Metric Geometry, 010307 mathematical physics, 0101 mathematics, Complex Variables (math.CV), Mathematics
Abstract

International audience; We characterize quasiconformal mappings in terms of the distortion of the vertices of equilateral triangles.

Published
2019

67. Analysis of 3D non-linear Stokes problem coupled to transport-diffusion for shear-thinning heterogeneous microscale flows, applications to digital rock physics and mucociliary clearance

Author

Robin Chatelin, David Sanchez, Philippe Poncet, Laurène Hume, Institut de Mathématiques de Toulouse UMR5219 (IMT), Université Toulouse 1 Capitole (UT1)-Université Toulouse - Jean Jaurès (UT2J)-Université Toulouse III - Paul Sabatier (UPS), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-PRES Université de Toulouse-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Mathématiques et de leurs Applications [Pau] (LMAP), Université de Pau et des Pays de l'Adour (UPPA)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Tribologie et Dynamique des Systèmes (LTDS), École Centrale de Lyon (ECL), Université de Lyon-Université de Lyon-École Nationale des Travaux Publics de l'État (ENTPE)-Ecole Nationale d'Ingénieurs de Saint Etienne-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 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), Université de Lyon-Université de Lyon-École Nationale des Travaux Publics de l'État (ENTPE)-Ecole Nationale d'Ingénieurs de Saint Etienne (ENISE)-Centre National de la Recherche Scientifique (CNRS), Institut de Mathématiques de Toulouse UMR5219 ( IMT ), Université Toulouse 1 Capitole ( UT1 ) -Université Toulouse - Jean Jaurès ( UT2J ) -Université Toulouse III - Paul Sabatier ( UPS ), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-PRES Université de Toulouse-Institut National des Sciences Appliquées - Toulouse ( INSA Toulouse ), Institut National des Sciences Appliquées ( INSA ) -Institut National des Sciences Appliquées ( INSA ) -Centre National de la Recherche Scientifique ( CNRS ), Laboratoire de Mathématiques et de leurs Applications [Pau] ( LMAP ), Université de Pau et des Pays de l'Adour ( UPPA ) -Centre National de la Recherche Scientifique ( CNRS ), Laboratoire de Tribologie et Dynamique des Systèmes ( LTDS ), École Centrale de Lyon ( ECL ), and Université de Lyon-Université de Lyon-École Nationale des Travaux Publics de l'État ( ENTPE ) -Ecole Nationale d'Ingénieurs de Saint Etienne-Centre National de la Recherche Scientifique ( CNRS )

Subjects
Generalized Stokes equations, 010103 numerical & computational mathematics, 01 natural sciences, 010305 fluids & plasmas, Physics::Fluid Dynamics, [ MATH.MATH-AP ] Mathematics [math]/Analysis of PDEs [math.AP], mucociliary clearance, 0103 physical sciences, [MATH.MATH-AP]Mathematics [math]/Analysis of PDEs [math.AP], [PHYS.MECA.MEFL]Physics [physics]/Mechanics [physics]/Fluid mechanics [physics.class-ph], 0101 mathematics, Diffusion (business), MSC: 35Q30, 76D03, 76D07, 65M25, 68U20, 76Z05, 92B05, Microscale chemistry, porous media flows, Physics, Numerical Analysis, Shear thinning, digital rock physics, Applied Mathematics, Numerical analysis, shear-thinning, variable viscosity, Mechanics, [ MATH.MATH-NA ] Mathematics [math]/Numerical Analysis [math.NA], bio-mathematics, Action (physics), Computational Mathematics, Nonlinear system, Flow (mathematics), Modeling and Simulation, Porous medium, Analysis, [MATH.MATH-NA]Mathematics [math]/Numerical Analysis [math.NA], 3D flows
Abstract

This study provides the analysis of the generalized 3D Stokes problem in a time dependent domain, modeling a solid in motion. The fluid viscosity is a non-linear function of the shear-rate and depends on a transported and diffused quantity. This is a natural model of flow at very low Reynolds numbers, typically at the microscale, involving a miscible, heterogeneous and shear-thinning incompressible fluid filling a complex geometry in motion. This one-way coupling is meaningful when the action produced by a solid in motion has a dominant effect on the fluid. Several mathematical aspects are developed. The penalized version of this problem is introduced, involving the penalization of the solid in a deformable motion but defined in a simple geometry (a periodic domain and/or between planes), which is of crucial interest for many numerical methods. All the equations of this partial differential system are analyzed separately, and then the coupled model is shown to be well-posed and to converge toward the solution of the initial problem. In order to illustrate the pertinence of such models, two meaningful micrometer scale real-life problems are presented: on the one hand, the dynamics of a polymer percolating the pores of a real rock and miscible in water; on the other hand, the dynamics of the strongly heterogeneous mucus bio-film, covering the human lungs surface, propelled by the vibrating ciliated cells. For both these examples the mathematical hypothesis are satisfied.

Published
2019
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68. Symbolic Computations of First Integrals for Polynomial Vector Fields

Author

Guillaume Chèze, Thierry Combot, Institut de Mathématiques de Toulouse UMR5219 (IMT), 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), Institut de Mathématiques de Bourgogne [Dijon] (IMB), Centre National de la Recherche Scientifique (CNRS)-Université de Franche-Comté (UFC), Université Bourgogne Franche-Comté [COMUE] (UBFC)-Université Bourgogne Franche-Comté [COMUE] (UBFC)-Université de Bourgogne (UB), Institut de Mathématiques de Toulouse UMR5219 ( IMT ), 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 ) -PRES Université de Toulouse-Université Paul Sabatier - Toulouse 3 ( UPS ) -Université Toulouse - Jean Jaurès ( UT2J ) -Université Toulouse 1 Capitole ( UT1 ), Institut de Mathématiques de Bourgogne [Dijon] ( IMB ), Université de Bourgogne ( UB ) -Centre National de la Recherche Scientifique ( CNRS ), Université Toulouse 1 Capitole ( UT1 ) -Université Toulouse - Jean Jaurès ( UT2J ) -Université Toulouse III - Paul Sabatier ( UPS ), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-PRES Université de Toulouse-Institut National des Sciences Appliquées - Toulouse ( INSA Toulouse ), Institut National des Sciences Appliquées ( INSA ) -Institut National des Sciences Appliquées ( INSA ) -Centre National de la Recherche Scientifique ( CNRS ), 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 Université de Bourgogne (UB)-Université Bourgogne Franche-Comté [COMUE] (UBFC)-Centre National de la Recherche Scientifique (CNRS)

Subjects
FOS: Computer and information sciences, Computer Science - Symbolic Computation, [INFO.INFO-CC]Computer Science [cs]/Computational Complexity [cs.CC], [ MATH.MATH-CA ] Mathematics [math]/Classical Analysis and ODEs [math.CA], [ MATH.MATH-DS ] Mathematics [math]/Dynamical Systems [math.DS], [MATH.MATH-DS]Mathematics [math]/Dynamical Systems [math.DS], FOS: Physical sciences, 010103 numerical & computational mathematics, Dynamical Systems (math.DS), [MATH.MATH-CA]Mathematics [math]/Classical Analysis and ODEs [math.CA], Symbolic Computation (cs.SC), Computational Complexity (cs.CC), 01 natural sciences, Section (fiber bundle), ComputingMethodologies_SYMBOLICANDALGEBRAICMANIPULATION, Classical Analysis and ODEs (math.CA), FOS: Mathematics, Degree of a polynomial, [NLIN.NLIN-SI]Nonlinear Sciences [physics]/Exactly Solvable and Integrable Systems [nlin.SI], 0101 mathematics, [MATH]Mathematics [math], Mathematics - Dynamical Systems, Mathematics, Discrete mathematics, [INFO.INFO-SC]Computer Science [cs]/Symbolic Computation [cs.SC], Degree (graph theory), Nonlinear Sciences - Exactly Solvable and Integrable Systems, Applied Mathematics, 010102 general mathematics, Symbolic computations, liouvillian functions, [ INFO.INFO-SC ] Computer Science [cs]/Symbolic Computation [cs.SC], Randomized algorithm, Computational Mathematics, Computer Science - Computational Complexity, First integrals, [ INFO.INFO-CC ] Computer Science [cs]/Computational Complexity [cs.CC], Computational Theory and Mathematics, Mathematics - Classical Analysis and ODEs, Ordinary differential equation, Bounded function, Linear algebra, Exponent, ordinary differential-equations, Exactly Solvable and Integrable Systems (nlin.SI), Analysis, Complexity analysis, [ NLIN.NLIN-SI ] Nonlinear Sciences [physics]/Exactly Solvable and Integrable Systems [nlin.SI]
Abstract

In this article, we show how to generalize to the Darbouxian, Liouvillian and Riccati case the extactic curve introduced by J. Pereira. With this approach, we get new algorithms for computing, if it exists, a rational, Darbouxian, Liouvillian or Riccati first integral with bounded degree of a polynomial planar vector field. We give probabilistic and deterministic algorithms. The arithmetic complexity of our probabilistic algorithm is in $$\tilde{\mathcal {O}}(N^{\omega +1})$$ , where N is the bound on the degree of a representation of the first integral and $$\omega \in [2;3]$$ is the exponent of linear algebra. This result improves previous algorithms. Our algorithms have been implemented in Maple and are available on the authors’ websites. In the last section, we give some examples showing the efficiency of these algorithms.

Published
2018
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69. Assessment of numerical methods for fully resolved simulations of particle-laden turbulent flows

Author

Pedro Costa, Jos Derksen, Stéphane Vincent, Wim-Paul Breugem, J.C. Brändle de Motta, Lian-Ping Wang, P. Barbaresco, Cheng Peng, Pascal Fede, Jean-Luc Estivalezes, Nicolas Renon, Eric Climent, Institut de mécanique des fluides de Toulouse (IMFT), Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées, Complexe de recherche interprofessionnel en aérothermochimie (CORIA), Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences appliquées Rouen Normandie (INSA Rouen Normandie), Normandie Université (NU)-Institut National des Sciences Appliquées (INSA)-Normandie Université (NU)-Institut National des Sciences Appliquées (INSA)-Université de Rouen Normandie (UNIROUEN), Normandie Université (NU), Delft University of Technology (TU Delft), Department of Mechanics (KTH), University of Aberdeen, University of Delaware [Newark], Southern University of Science and Technology of China (SUSTech), ONERA / DMPE, Université de Toulouse [Toulouse], ONERA-PRES Université de Toulouse, Calcul en Midi-Pyrénées (CALMIP), Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-PRES Université de Toulouse-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Laboratoire de Modélisation et Simulation Multi Echelle (MSME), Centre National de la Recherche Scientifique (CNRS)-Université Paris-Est Créteil Val-de-Marne - Paris 12 (UPEC UP12)-Université Paris-Est Marne-la-Vallée (UPEM), Institut National des Sciences Appliquées (INSA)-Normandie Université (NU)-Institut National des Sciences Appliquées (INSA)-Normandie Université (NU)-Université de Rouen Normandie (UNIROUEN), Centre National de la Recherche Scientifique - CNRS (FRANCE), Institut National Polytechnique de Toulouse - Toulouse INP (FRANCE), Institut National des Sciences Appliquées de Toulouse - INSA (FRANCE), Institut National des Sciences Appliquées de Rouen - INSA (FRANCE), Office National d'Etudes et Recherches Aérospatiales - ONERA (FRANCE), Royal Institute of Technology – KTH (SWEDEN), Université de Rouen - UR (FRANCE), Université Paris Est Créteil Val de Marne - UPEC (FRANCE), Université Toulouse III - Paul Sabatier - UT3 (FRANCE), University of Delaware Newark - UDEL (USA), Delft University of Technology - TU Delft (NETHERLANDS), Southern University of Science and Technology - SUSTech (CHINA), Université Paris-Est Marne-La-Vallée - UPEM (FRANCE), Department of Mechanics (Stockholm, Sweden), The French Aerospace Lab (Toulouse, France), Centre National de la Recherche Scientifique (CNRS)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Institut National Polytechnique (Toulouse) (Toulouse INP), Laboratoire Modélisation et Simulation Multi-Echelle (MSME), Université Paris-Est Créteil Val-de-Marne - Paris 12 (UPEC UP12)-Centre National de la Recherche Scientifique (CNRS)-Université Gustave Eiffel, Université de Rouen Normandie (UNIROUEN), Normandie Université (NU)-Normandie Université (NU)-Institut national des sciences appliquées Rouen Normandie (INSA Rouen Normandie), Institut National des Sciences Appliquées (INSA)-Normandie Université (NU)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS), Southern University of Science and Technology (SUSTech), Université Paris-Est Marne-la-Vallée (UPEM)-Université Paris-Est Créteil Val-de-Marne - Paris 12 (UPEC UP12)-Centre National de la Recherche Scientifique (CNRS), and Centre National de la Recherche Scientifique (CNRS)-PRES Université de Toulouse-Université Toulouse III - Paul Sabatier (UT3)

Subjects
Particle statistics, General Computer Science, Mécanique des fluides, Lattice Boltzmann methods, FINITE-SIZE PARTICLE, Direct numerical simulations, 01 natural sciences, 010305 fluids & plasmas, [SPI.MECA.MEFL]Engineering Sciences [physics]/Mechanics [physics.med-ph]/Fluids mechanics [physics.class-ph], Physics::Fluid Dynamics, 0103 physical sciences, Initial value problem, DIRECT NUMERICAL SIMULATION, Penalty method, 0101 mathematics, ComputingMilieux_MISCELLANEOUS, ECOULEMENT DE PARTICULE CHARGE, Physics, Turbulence, PARTICLE-LADEN FLOW, Numerical analysis, [SPI.FLUID]Engineering Sciences [physics]/Reactive fluid environment, General Engineering, Mechanics, Immersed boundary method, Particle-laden flows, 010101 applied mathematics, Turbulence kinetic energy, TURBULENCE, Finite-size particles, SIMULATION NUMERIQUE DIRECTE
Abstract

International audience; During the last decade, many approaches for resolved-particle simulation (RPS) have been developed for numerical studies of finite size particle-laden turbulent flows. In this paper, three RPS approaches are compared for a particle-laden decaying turbulence case. These methods are, the Volume-of-Fluid Lagrangian method, based on the viscosity penalty method (VoF-Lag); a direct forcing Immersed Boundary Method, based on a regularized delta-function approach for the fluid/solid coupling (IBM); and the Bounce Back scheme developed for Lattice Boltzmann method (LBM-BB). The physics and the numerical performances of the methods are analyzed. Modulation of turbulence is observed for all the methods, with a faster decay of turbulent kinetic energy compared to the single-phase case. Lagrangian particle statistics, such as the velocity probability density function and the velocity autocorrelation function, show minor differences among the three methods. However, major differences between the codes are observed in the evolution of the particle kinetic energy. These differences are related to the treatment of the initial condition when the particles are inserted in an initially single-phase turbulence. The averaged particle/fluid slip velocity is also analyzed, showing similar behavior as compared to the results referred in the literature. The computational performances of the different methods differ significantly. The VoF-Lag method appears to be computationally most expensive. Indeed, this method is not adapted to turbulent cases. The IBM and LBM-BB implementations show very good scaling.

Published
2018
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70. Accurate estimate of drag forces using particle-resolved direct numerical simulations

Author

Mohamed-Amine Chadil, Jean-Luc Estivalezes, Stéphane Vincent, Institut de mécanique des fluides de Toulouse (IMFT), Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées, Institut de Mécanique et d'Ingénierie de Bordeaux (I2M), Institut National de la Recherche Agronomique (INRA)-Université de Bordeaux (UB)-École Nationale Supérieure d'Arts et Métiers (ENSAM), Arts et Métiers Sciences et Technologies, HESAM Université (HESAM)-HESAM Université (HESAM)-Arts et Métiers Sciences et Technologies, HESAM Université (HESAM)-HESAM Université (HESAM)-Institut Polytechnique de Bordeaux-Centre National de la Recherche Scientifique (CNRS), Laboratoire MSNE, ONERA / DMPE, Université de Toulouse [Toulouse], ONERA-PRES Université de Toulouse, École Nationale Supérieure d'Arts et Métiers (ENSAM), HESAM Université (HESAM)-HESAM Université (HESAM)-Institut Polytechnique de Bordeaux-Institut National de la Recherche Agronomique (INRA)-Centre National de la Recherche Scientifique (CNRS)-Université de Bordeaux (UB), HESAM Université (HESAM)-HESAM Université (HESAM)-Institut Polytechnique de Bordeaux-Centre National de la Recherche Scientifique (CNRS)-Université de Bordeaux (UB)-Institut National de la Recherche Agronomique (INRA), Laboratoire Modélisation et Simulation Multi-Echelle (MSME), Université Paris-Est Créteil Val-de-Marne - Paris 12 (UPEC UP12)-Centre National de la Recherche Scientifique (CNRS)-Université Gustave Eiffel, PRES Université de Toulouse-ONERA, Centre National de la Recherche Scientifique - CNRS (FRANCE), Institut National Polytechnique de Toulouse - INPT (FRANCE), Office National d'Etudes et Recherches Aérospatiales - ONERA (FRANCE), Université Toulouse III - Paul Sabatier - UT3 (FRANCE), Université de Bordeaux (FRANCE), Université Paris-Est Marne-La-Vallée - UPEM (FRANCE), and Institut National Polytechnique de Toulouse - Toulouse INP (FRANCE)

Subjects
DNS, Mécanique des fluides, Computational Mechanics, Extrapolation, MATERIAL INTERFACE, 02 engineering and technology, 01 natural sciences, 010305 fluids & plasmas, [SPI.MECA.MEFL]Engineering Sciences [physics]/Mechanics [physics.med-ph]/Fluids mechanics [physics.class-ph], Physics::Fluid Dynamics, symbols.namesake, [SPI]Engineering Sciences [physics], 0203 mechanical engineering, NOMBRE DE REYNOLDS, 0103 physical sciences, Particle resolved simulation, ComputingMilieux_MISCELLANEOUS, Physics, [PHYS]Physics [physics], Turbulence, Mechanical Engineering, Reynolds number, Mechanics, INTERFACE MATERIEL, ECOULEMENT TURBULENT, 020303 mechanical engineering & transports, IMMERSED FINITE, Drag, TURBULENCE FLOW, Solid mechanics, Compressibility, symbols, Particle, REYNOLDS NUMBER, Drag force, Interpolation
Abstract

International audience; An accurate force estimate for finite-size particle simulations is proposed based on Lagrange extrapolation of third order, coupled with a Taylor interpolation of same order, to estimate pressure and viscous constraints on the surface of particles. The main point of our approach is to upwind the interpolation support in the normal direction to the fluid/solid interface so as to use only fluid values to estimate forces. Also, detailed validations of forces are considered for estimating accuracy and convergence order of the method on various incompressible motions such as the flow around an isolated particle at various Reynolds numbers and flows across packed spheres under Faced-Centered Cubic, random and bi-disperse arrangements.

Published
2018
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71. The Rings of Jupiter as Seen by the Electron and Proton Radiation Belt Model Salammbô

Author

Quentin Nénon, Angélica Sicard, P. Caron, ONERA / DPHY, Université de Toulouse [Toulouse], ONERA-PRES Université de Toulouse, and PRES Université de Toulouse-ONERA

Subjects
010504 meteorology & atmospheric sciences, Galileo Probe, Electron, 01 natural sciences, Jovian, Jupiter, symbols.namesake, RADIATION BELT, 0103 physical sciences, ANNEAUX DE JUPITER, CEINTURES DE RADIATIONS, 010303 astronomy & astrophysics, Optical depth, 0105 earth and related environmental sciences, Physics, JUPITER RING, MODELE SALAMMBO, Radius, [PHYS.PHYS.PHYS-SPACE-PH]Physics [physics]/Physics [physics]/Space Physics [physics.space-ph], Magnetic field, Geophysics, SALAMMBO MODEL, [SDU]Sciences of the Universe [physics], Van Allen radiation belt, Physics::Space Physics, symbols, General Earth and Planetary Sciences, Astrophysics::Earth and Planetary Astrophysics, Atomic physics
Abstract

International audience; A modeling of the effect of the rings of Jupiter on trapped >3‐MeV electrons and protons is proposed. The effect is then added to the physical model Salammbô and discussed against in situ measurements obtained by the Pioneer 11 and Galileo Probe missions. It is first shown that there is no evidence of an effect of the rings on the Jovian radiation belts, thanks to the new internal magnetic field model proposed by the Juno mission. Two grain populations are then studied: small grains, with a radius lower than 100 μm, are shown to not affect observable >3‐MeV trapped particles. The normal optical depth of grains with a radius larger than 2 cm, which may exist in the main ring, is constrained to be lower than 10−7 by the Salammbô model.

Published
2018
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72. Comparison of molecular contamination models based on TGA/MS experiments

Author

Vanhove, Emilie, Grosjean, Eudes, Rioland, Guillaume, Faye, Delphine, ONERA / DPHY, Université de Toulouse [Toulouse], PRES Université de Toulouse-ONERA, Centre National d'Études Spatiales [Toulouse] (CNES), André, Cécile, and ONERA-PRES Université de Toulouse

Subjects
TGA/MS EXPERIMENTS, EXPERIENCES TGA/MS, CONTAMINATION MOLECULAIRE, [PHYS.PHYS.PHYS-SPACE-PH] Physics [physics]/Physics [physics]/Space Physics [physics.space-ph], MOLECULAR CONTAMINATION, [PHYS.PHYS.PHYS-SPACE-PH]Physics [physics]/Physics [physics]/Space Physics [physics.space-ph]
Abstract

International audience; Several competing models of outgassing and reemission have been developed to describe molecular contamination. Similarly, European, American and Japanese space agencies advocate very different methods for estimating the properties of spatial contaminants. However, for flight predictions to be reliable, it is necessary to have both relevant models and good input parameters for these models (robust characterization methods).Thus, from one model to another and from one characterization method to another, the simulations very often vary by several orders of magnitude. It is therefore very important to be able to determine which methodologies provide reliable results. The coupling of the thermogravimetric and mass spectrometry analyzes makes it possible to establish the individual behavior of outgassing and of reemission of each chemical species of a spatial contaminant, separately. In this study, using these new experimental data, the most commonly used models are compared and discussed, as well as their impact on predictions of contamination levels. Alternative models are also proposed. This work may contribute to the evolution of characterization protocols and numerical models, with important consequences for simulation results.

Published
2018

73. Polymer radiation testing guidelines for space application

Author

Laurent, E., Jochem, H., Dagras, S., Lewandowski, Simon, Sukhaseum, N., Centre National d'Études Spatiales [Toulouse] (CNES), Thales Alenia Space (TAS), THALES, Airbus Defence and Space [Toulouse], ONERA / DPHY, Université de Toulouse [Toulouse], PRES Université de Toulouse-ONERA, TRAD [Labège], TRAD, and ONERA-PRES Université de Toulouse

Subjects
DEGRADATION DE MATERIAUX, IRRADIATION DE POLYMERES, POLYMER RADIATION, MATERIAL DEGRADATION, [PHYS.PHYS.PHYS-SPACE-PH]Physics [physics]/Physics [physics]/Space Physics [physics.space-ph], [SPI.MAT]Engineering Sciences [physics]/Materials
Abstract

International audience; Materials used to manufacture spacecraft may experience a significant radiation stress during their live flight. The absorbed dose profil into these materials depends on the material nature, its location on the spacecraft and the mission parameters (duration, type of orbit). In order to assess the material functionality degradation due to radiation and estimate the end of life (EOL) properties, a qualification phase is necessary involving on ground experimental tests. This paper provides a synthetic compilation about the main steps of a qualification and the test parameters to determine and fix for the irradiation experimental tests. The aim is to provide adequate guidelines for testing. Recommendations are made to optimize the pre-irradiation, experimental and post-irradiation phases of the material qualification. These recommendations are based on experimental tests especially performed for this work, as well as on European prime contractor internal qualification processes.Following these recommendations, warnings are presented, in order to raise awareness on the various points that may affect the definition of the test plan and the representativeness of the results obtained with this test.

Published
2018

74. Compact Modelling of Single Event Transient in Bulk MOSFET for SPICE: Application to Elementary Circuit

Author

Guillaume Hubert, Olivier Rozeau, Joris Lacord, Sebastien Martinie, O. Billoint, Jean-Charles Barbe, Thierry Poiroux, Neil Rostand, ONERA / DPHY, Université de Toulouse [Toulouse], PRES Université de Toulouse-ONERA, Commissariat à l'énergie atomique et aux énergies alternatives - Laboratoire d'Electronique et de Technologie de l'Information (CEA-LETI), Direction de Recherche Technologique (CEA) (DRT (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), ONERA-PRES Université de Toulouse, and André, Cécile

Subjects
Computer science, Spice, Integrated circuit, Hardware_PERFORMANCEANDRELIABILITY, 01 natural sciences, law.invention, Set (abstract data type), [SPI]Engineering Sciences [physics], law, 0103 physical sciences, Compact model, Electronic engineering, Static random-access memory, [SPI.NANO]Engineering Sciences [physics]/Micro and nanotechnologies/Microelectronics, [PHYS.PHYS.PHYS-SPACE-PH] Physics [physics]/Physics [physics]/Space Physics [physics.space-ph], RADIATIONS, Electronic circuit, Shift register, 010302 applied physics, SPICE, Radiation, 010308 nuclear & particles physics, MODELE COMPACT, [SPI.TRON] Engineering Sciences [physics]/Electronics, [PHYS.PHYS.PHYS-SPACE-PH]Physics [physics]/Physics [physics]/Space Physics [physics.space-ph], [SPI.TRON]Engineering Sciences [physics]/Electronics, IONS LOURDS, CMOS, Single event upset, Heavy ion, SET, Bulk transistor, SEU, Hardware_LOGICDESIGN
Abstract

International audience; Single Event Transients (SET) are important issues concerning reliability of CMOS circuits. They lead to occurrence of soft errors in integrated circuits, such as Single Event Upset (SEU) which consists in unexpected bit state switch in SRAM cells [1,2]. We can find models which describe SET in literature [1, 5] but they are not compact (i e. physical model implemented in Verilog-A). In previous work [6], we proposed a theoretical SET model but the implementation in Verilog-A was still challenging. Here, we describe the implementation in Verilog-A of this model and use it through standard SPICE simulations to study the effect of SET on SRAM cell and shift register.

Published
2018
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75. Compact Modeling of Single Event Latchup of integrated CMOS circuit

Author

Al Youssef, Ahmad, Artola, Laurent, Ducret, S., Hubert, Guillaume, ONERA / DPHY, Université de Toulouse [Toulouse], ONERA-PRES Université de Toulouse, SOFRADIR (Veurey-Voroize), André, Cécile, and PRES Université de Toulouse-ONERA

Subjects
SEE PREDICTION, COMPACT MODELING, CMOS, PRÉDICTION SEE, [PHYS.PHYS.PHYS-SPACE-PH]Physics [physics]/Physics [physics]/Space Physics [physics.space-ph], SINGLE EVENT LATCHUP, DESIGN, [PHYS.PHYS.PHYS-PLASM-PH]Physics [physics]/Physics [physics]/Plasma Physics [physics.plasm-ph], [PHYS.PHYS.PHYS-PLASM-PH] Physics [physics]/Physics [physics]/Plasma Physics [physics.plasm-ph], TECHNOLOGY COMPUTER-AIDED DESIGN (TCAD) SIMULATION, COMPLEMENTARY METAL-OXIDE SEMICONDUCTOR (CMOS), TCAD SIMULATION, SPICE SIMULATION, [PHYS.PHYS.PHYS-SPACE-PH] Physics [physics]/Physics [physics]/Space Physics [physics.space-ph], SINGLE-EVENT LATCHUP (SEL), MODÉLISATION COMPACTE, SIMULATION TCAD, CROSS SECTION, COMPLEMENTARY METAL– OXIDE–SEMICONDUCTOR
Abstract

International audience; This paper presents a compact model of latchup taking into account design and process dependence. This model was used to confirm the SEL robustness of DFFs used in Readout Circuit of Infrared-sensors developed by Sofradir.ouThis paper presents a compact model of latchup considering design and process dependence. The new approach is more realistic and inspirited from the classical model. This model was used to confirm the single-event latchup (SEL) robustness of D-flip-flops (DFFs) used in Readout Circuit of Infrared-sensors developed by Sofradir. SEL cross sections are presented by the mean of the Monte Carlo tool MUSCA SEP3 in order to validate the new latchup modeling approach.

Published
2018

76. The study of the anisotropy's influence on the response function of radiation monitors

Author

Ruffenach, Marine, Bourdarie, Sebastien, Sicard, Angélica, Falguere, Didier, ONERA / DPHY, Université de Toulouse [Toulouse], ONERA-PRES Université de Toulouse, André, Cécile, and PRES Université de Toulouse-ONERA

Subjects
ANISOTROPY, MONITEUR DE RADIATION, RADIATION MONITOR, ANISOTROPIE, Physics::Space Physics, Astrophysics::Earth and Planetary Astrophysics, [PHYS.PHYS.PHYS-SPACE-PH] Physics [physics]/Physics [physics]/Space Physics [physics.space-ph], [PHYS.PHYS.PHYS-SPACE-PH]Physics [physics]/Physics [physics]/Space Physics [physics.space-ph]
Abstract

International audience; Some satellites are equipped with radiation monitors used to scan different regions of the magnetosphere. Data processing of these monitors show that a lot of particles are detected during descending orbits (when latitude goes down) if we compare with ascending orbits (when latitude goes up) in the case of the Argentinian satellite SAC-D. Indeed, monitors do not always look in the same direction in respect to the local magnetic field for a same region of space depending on the type of orbit. These data reflect anisotropy in radiation belts and the objective is to study the anisotropy's influence on the response function of radiation monitors. Also, a comparison between two Monte-Carlo methods, GEANT4 and MCNPX, will be performed.

Published
2018

77. A new model for the plasma particles fluxes (part of GREEN model)

Author

Sicard, Angélica, Boscher, Daniel, Lazaro, Didier, Standarovski, Denis, Ecoffet, Robert, ONERA / DPHY, Université de Toulouse [Toulouse], PRES Université de Toulouse-ONERA, Centre National d'Études Spatiales [Toulouse] (CNES), ONERA-PRES Université de Toulouse, and André, Cécile

Subjects
MODEL, MODELE, PLASMA, [PHYS.PHYS.PHYS-PLASM-PH]Physics [physics]/Physics [physics]/Plasma Physics [physics.plasm-ph], [PHYS.PHYS.PHYS-PLASM-PH] Physics [physics]/Physics [physics]/Plasma Physics [physics.plasm-ph], Physics::Space Physics, [PHYS.PHYS.PHYS-SPACE-PH] Physics [physics]/Physics [physics]/Space Physics [physics.space-ph], [PHYS.PHYS.PHYS-SPACE-PH]Physics [physics]/Physics [physics]/Space Physics [physics.space-ph]
Abstract

International audience; A new specification model of low energy particles fluxes, included in GREEN model, has been developed at ONERA. This model is based on several data sets, from low altitudes with NOAA-POES measurements to higher altitudes with POLAR, THEMIS and LANL measurements. This model provides mean MLT dependent electron and proton fluxes between L=2 and L=10 for energies between 0.19 keV and few 10s of keV. In this paper, the model is compared to AE9/SPM model and Van Allen Probe measurements.

Published
2018

78. Impact of the Earth’s magnetic field secular drift on the low altitude proton radiation belt from years 1900 to 2050

Author

Denis Standarovski, S. Bourdarie, Robert Ecoffet, Julien Aubert, G. Hulot, Angélica Sicard, Alexandre Fournier, ONERA / DPHY, Université de Toulouse [Toulouse], ONERA-PRES Université de Toulouse, Institut de Physique du Globe de Paris (IPGP), Institut national des sciences de l'Univers (INSU - CNRS)-IPG PARIS-Université Paris Diderot - Paris 7 (UPD7)-Université de La Réunion (UR)-Centre National de la Recherche Scientifique (CNRS), Centre National d'Études Spatiales [Toulouse] (CNES), Centre National de la Recherche Scientifique (CNRS)-Université de La Réunion (UR)-Université Paris Diderot - Paris 7 (UPD7)-IPG PARIS-Institut national des sciences de l'Univers (INSU - CNRS), PRES Université de Toulouse-ONERA, and Institut de Physique du Globe de Paris

Subjects
[PHYS.ASTR.HE]Physics [physics]/Astrophysics [astro-ph]/High Energy Astrophysical Phenomena [astro-ph.HE], Nuclear and High Energy Physics, 010504 meteorology & atmospheric sciences, Proton, [SDU.STU.GP]Sciences of the Universe [physics]/Earth Sciences/Geophysics [physics.geo-ph], [PHYS.ASTR.EP]Physics [physics]/Astrophysics [astro-ph]/Earth and Planetary Astrophysics [astro-ph.EP], Radiation, 01 natural sciences, Space exploration, CHAMP MAGNETIQUE, Altitude, Proton radiation, 0103 physical sciences, [PHYS.PHYS.PHYS-INS-DET]Physics [physics]/Physics [physics]/Instrumentation and Detectors [physics.ins-det], Electrical and Electronic Engineering, Aerospace engineering, TRAPPED PROTONS, 0105 earth and related environmental sciences, Spacecraft, 010308 nuclear & particles physics, business.industry, Astrophysics::Instrumentation and Methods for Astrophysics, SOUTH ATLANTIC ANOMALY FORECAST, CEINTURES DE RADIATION, RADIATION BELTS, [PHYS.PHYS.PHYS-SPACE-PH]Physics [physics]/Physics [physics]/Space Physics [physics.space-ph], Magnetic field, [SPI.ELEC]Engineering Sciences [physics]/Electromagnetism, Earth's magnetic field, Nuclear Energy and Engineering, 13. Climate action, Physics::Space Physics, Environmental science, Index Terms-radiation belts, Astrophysics::Earth and Planetary Astrophysics, business
Abstract

International audience; The effects of the space radiation environment on spacecraft systems and instruments are significant design considerations for space missions. In order to meet these challenges and have reliable, cost-effective designs, the radiation environment must be understood and accurately modeled. The low altitude proton environment varies slowly in time due to the secular drift of the Earth’s main magnetic field and due to the evolution of the solar cycle. The purpose of this paper is to extend the OPAL model [1] capabilities by introducing a prediction of the Earth’s main magnetic field model up to year 2050. Impact on low altitude spacecraft radiation specification for next space missions is then assessed.

Published
2018
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79. Experimental Study of the NIEL Scaling for Silicon Devices

Author

Christophe Inguimbert, T. Nuns, B. Dryer, S. Soonckindt, Christian Poivey, T. Buggey, André, Cécile, ONERA / DPHY, Université de Toulouse [Toulouse], PRES Université de Toulouse-ONERA, The Open University [Milton Keynes] (OU), European Space Research and Technology Centre (ESTEC), European Space Agency (ESA), and ONERA-PRES Université de Toulouse

Subjects
Materials science, SPACE ENVIRONMENT, Proton, Silicon, chemistry.chemical_element, Damage factor, Electron, DOMMAGE DE DEPLACEMENT, PERTE D'ENERGIE NON IONISANTE, 01 natural sciences, law.invention, [PHYS.PHYS.PHYS-PLASM-PH]Physics [physics]/Physics [physics]/Plasma Physics [physics.plasm-ph], law, 0103 physical sciences, Damage effects, Scaling, [PHYS.PHYS.PHYS-SPACE-PH] Physics [physics]/Physics [physics]/Space Physics [physics.space-ph], 010308 nuclear & particles physics, ENVIRONNEMENT SPATIAL, [PHYS.PHYS.PHYS-SPACE-PH]Physics [physics]/Physics [physics]/Space Physics [physics.space-ph], Computational physics, Photodiode, DISPLACEMENT DAMAGE, chemistry, [PHYS.PHYS.PHYS-PLASM-PH] Physics [physics]/Physics [physics]/Plasma Physics [physics.plasm-ph], NON-IONIZING ENERGY LOSS
Abstract

International audience; This paper proposes some new experimental data comparing the damage factor of silicon devices with the NIEL after electron, proton and gamma irradiations. The results show that the measured damage factors fit better with the "effective" NIEL, an alternative model of displacement damage effects, than with the classical one.

Published
2018
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80. Some drawbacks of finite modified logarithmic Sobolev inequalilities

Author

Laurent Miclo, Institut de Mathématiques de Toulouse UMR5219 (IMT), 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), ANR-12-BS01-0019,STAB,Stabilité du comportement asymptotique d'EDP, de processus stochastiques et de leurs discrétisations.(2012), 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), Université Toulouse 1 Capitole (UT1)-Université Toulouse - Jean Jaurès (UT2J)-Université Toulouse III - Paul Sabatier (UPS), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-PRES Université de Toulouse-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS), Institut de Mathématiques de Toulouse UMR5219 ( IMT ), Université Toulouse 1 Capitole ( UT1 ) -Université Toulouse - Jean Jaurès ( UT2J ) -Université Toulouse III - Paul Sabatier ( UPS ), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-PRES Université de Toulouse-Institut National des Sciences Appliquées - Toulouse ( INSA Toulouse ), Institut National des Sciences Appliquées ( INSA ) -Institut National des Sciences Appliquées ( INSA ) -Centre National de la Recherche Scientifique ( CNRS ), and ANR-12-BS01-0019,STAB,Stabilité du comportement asymptotique d'EDP, de processus stochastiques et de leurs discrétisations. ( 2012 )

Subjects
Logarithm, intersection method, General Mathematics, [ MATH.MATH-FA ] Mathematics [math]/Functional Analysis [math.FA], [MATH.MATH-FA]Mathematics [math]/Functional Analysis [math.FA], 01 natural sciences, Poincaré's inequality, Sobolev inequality, 010104 statistics & probability, Intersection, 0101 mathematics, ComputingMilieux_MISCELLANEOUS, finite irreducible Markov generator, Mathematics, AMS MSC2010: primary: 46E39, secondary: 60J27, 94A17, 60E15, 15A18, symmetrization, Markov chain, 010102 general mathematics, Mathematical analysis, umbrella sampling, Sobolev space, [MATH.MATH-PR]Mathematics [math]/Probability [math.PR], Symmetrization, Spectral gap, Invariant measure, [ MATH.MATH-PR ] Mathematics [math]/Probability [math.PR], modified logarithmic Sobolev inequality
Abstract

Classically, finite modified logarithmic Sobolev inequalities are used to deduce a differential inequality for the evolution of the relative entropy with respect to the invariant measure. We will check that these inequalities are ill-behaved with respect, on one hand, to the symmetrization procedure, and on the other hand, to the umbrella sampling procedure for Poincaré inequalities. A short spectral proof of the latter method is given to estimate the spectral gap of a finite reversible Markov generator $L$ in terms of the spectral gap of the restrictions of $L$ on two subsets whose union is the whole state space and whose intersection is not empty.

Published
2018
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81. Analysis of Exposure to Solar and Galactic Cosmic Radiations of Flights Representative of the European International Air Traffic

Author

Guillaume Hubert, Sébastien Aubry, ONERA / DPHY, Université de Toulouse [Toulouse], PRES Université de Toulouse-ONERA, ONERA / DTIS, Université de Toulouse [Toulouse], and ONERA-PRES Université de Toulouse

Subjects
Meteorology, GROUND LEVEL ENHANCEMENT, ATMOSPHERIC IONIZING RADIATION, AMBIENT DOSE EQUIVALENTS, Biophysics, TRAFIC AÉRIEN EUROPÉEN, Cosmic ray, Space weather, Radiation Dosage, 01 natural sciences, 030218 nuclear medicine & medical imaging, Latitude, 03 medical and health sciences, 0302 clinical medicine, Radiation Protection, Radiation Monitoring, EUROPEAN INTERNATIONAL AIR TRAFFIC, Occupational Exposure, 0103 physical sciences, RADIATION EXPOSURE, Astrophysics::Solar and Stellar Astrophysics, Humans, Radiology, Nuclear Medicine and imaging, Solar Activity, 010303 astronomy & astrophysics, SOLAR FLARE, ANALYSES STATISTIQUES, Radiation, COSMIC cancer database, Solar flare, Equivalent dose, Altitude, ACCROISSEMENT TRANSITOIRE DU FLUX DE RAYONS COSMIQUES SOLAIRES DÉTECTÉS AU SOL DE LA TERRE, Air traffic control, ÉRUPTION SOLAIRE, Space Flight, STATISTICAL ANALYSES, RAYONNEMENT IONISANT ATMOSPHÉRIQUE, EXPOSITION AU RAYONNEMENT, [PHYS.PHYS.PHYS-SPACE-PH]Physics [physics]/Physics [physics]/Space Physics [physics.space-ph], 13. Climate action, Physics::Space Physics, Environmental science, DOSE AMBIANTE ÉQUIVALENTE, Longitude, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], Cosmic Radiation
Abstract

International audience; This study analyzed the impact of galactic and solar cosmic rays on ambient dose equivalent during airline travel. A high statistic of flights are considered, which is representative of European international air traffic. Flight paths are based on the Eurocontrol Demand Data Repository and consider realistic flight plans with and without regulations or updated with radar data from the Central Flow Management Unit. Ambient dose equivalent during flights was investigated during quiet solar periods and extreme solar flare events. Thus, the statistical analyses presented here take into account route characteristics (departure, arrival, continent, etc.) and space weather conditions. The findings of this work show the important influence of flight path, particularly the latitude, which drives the cutoff rigidity variations. Moreover, dose values vary drastically during ground level enhancement events, with the route path (latitude, longitude and altitude) and the phasing of the solar event. This study highlights the importance of monitoring these solar events and developing a physical approach to obtain reliable assessment of ambient dose equivalents.

Published
2018
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82. Semi-parametric estimation of the variogram of a Gaussian process with stationary increments

Author

Azaïs , Jean-Marc, Bachoc , François, Klein , Thierry, Lagnoux , Agnès, Nguyen , Thi Mong Ngoc, Institut de Mathématiques de Toulouse UMR5219 ( IMT ), 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 ) -PRES Université de Toulouse-Université Paul Sabatier - Toulouse 3 ( UPS ) -Université Toulouse - Jean Jaurès ( UT2J ) -Université Toulouse 1 Capitole ( UT1 ), Ecole Nationale de l'Aviation Civile ( ENAC ), Vietnam National University - Ho Chi Minh City ( VNU-HCM ), Institut de Mathématiques de Toulouse UMR5219 (IMT), 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), Vietnam National University - Ho Chi Minh City (VNU-HCM), Centre National de la Recherche Scientifique (CNRS)-PRES Université de Toulouse-Université Toulouse III - Paul Sabatier (UPS), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Université Toulouse - Jean Jaurès (UT2J)-Université Toulouse 1 Capitole (UT1), Ecole Nationale de l'Aviation Civile (ENAC), Université Toulouse 1 Capitole ( UT1 ) -Université Toulouse - Jean Jaurès ( UT2J ) -Université Toulouse III - Paul Sabatier ( UPS ), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-PRES Université de Toulouse-Institut National des Sciences Appliquées - Toulouse ( INSA Toulouse ), Institut National des Sciences Appliquées ( INSA ) -Institut National des Sciences Appliquées ( INSA ) -Centre National de la Recherche Scientifique ( CNRS ), 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
quadratic variations, aggregation of estimators, [MATH.MATH-ST]Mathematics [math]/Statistics [math.ST], asymptotic normality, FOS: Mathematics, Mathematics - Statistics Theory, Statistics Theory (math.ST), [ MATH.MATH-ST ] Mathematics [math]/Statistics [math.ST], moment method, scale covariance parameter
Abstract

International audience; We consider the semi-parametric estimation of a scale parameter of a one-dimensional Gaussian process with known smoothness. We suggest an estimator based on quadratic variations and on the moment method. We provide asymptotic approximations of the mean and variance of this estimator, together with asymptotic normality results, for a large class of Gaussian processes. We allow for general mean functions and study the aggregation of several estimators based on various variation sequences. In extensive simulation studies, we show that the asymptotic results accurately depict thefinite-sample situations already for small to moderate sample sizes. We also compare various variation sequences and highlight the efficiency of the aggregation procedure.

Published
2018

83. Sequential Test for the Lowest Mean: From Thompson to Murphy Sampling

Author

Kaufmann, Emilie, Koolen, Wouter, Garivier, Aurelien, Sequential Learning ( SEQUEL ), Inria Lille - Nord Europe, Institut National de Recherche en Informatique et en Automatique ( Inria ) -Institut National de Recherche en Informatique et en Automatique ( Inria ) -Centre de Recherche en Informatique, Signal et Automatique de Lille (CRIStAL) - UMR 9189 ( CRIStAL ), Ecole Centrale de Lille-Institut National de Recherche en Informatique et en Automatique ( Inria ) -Institut Mines-Télécom [Paris]-Université de Lille-Centre National de la Recherche Scientifique ( CNRS ) -Ecole Centrale de Lille-Institut Mines-Télécom [Paris]-Université de Lille-Centre National de la Recherche Scientifique ( CNRS ), Centre National de la Recherche Scientifique ( CNRS ), Centre de Recherche en Informatique, Signal et Automatique de Lille (CRIStAL) - UMR 9189 ( CRIStAL ), Ecole Centrale de Lille-Institut National de Recherche en Informatique et en Automatique ( Inria ) -Institut Mines-Télécom [Paris]-Université de Lille-Centre National de la Recherche Scientifique ( CNRS ), Centrum Wiskunde & Informatica ( CWI ), Institut de Mathématiques de Toulouse UMR5219 ( IMT ), 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 ) -PRES Université de Toulouse-Université Paul Sabatier - Toulouse 3 ( UPS ) -Université Toulouse - Jean Jaurès ( UT2J ) -Université Toulouse 1 Capitole ( UT1 ), ANR-16-CE40-0002,BADASS,Bandits Against Non-Stationarity and Structure ( 2016 ), Centrum Wiskunde & Informatica, Amsterdam (CWI), The Netherlands, Sequential Learning (SEQUEL), Institut National de Recherche en Informatique et en Automatique (Inria)-Institut National de Recherche en Informatique et en Automatique (Inria)-Centre de Recherche en Informatique, Signal et Automatique de Lille - UMR 9189 (CRIStAL), Centrale Lille-Université de Lille-Centre National de la Recherche Scientifique (CNRS)-Centrale Lille-Université de Lille-Centre National de la Recherche Scientifique (CNRS), Centre National de la Recherche Scientifique (CNRS), Centre de Recherche en Informatique, Signal et Automatique de Lille - UMR 9189 (CRIStAL), Centrale Lille-Université de Lille-Centre National de la Recherche Scientifique (CNRS), Centrum Wiskunde & Informatica (CWI), Unité de Mathématiques Pures et Appliquées (UMPA-ENSL), École normale supérieure de Lyon (ENS de Lyon)-Centre National de la Recherche Scientifique (CNRS), Modèles de calcul, Complexité, Combinatoire (MC2), Laboratoire de l'Informatique du Parallélisme (LIP), École normale supérieure de Lyon (ENS de Lyon)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut National de Recherche en Informatique et en Automatique (Inria)-Centre National de la Recherche Scientifique (CNRS)-École normale supérieure de Lyon (ENS de Lyon)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut National de Recherche en Informatique et en Automatique (Inria)-Centre National de la Recherche Scientifique (CNRS), ANR-16-CE40-0002,BADASS,BANDITS MANCHOTS POUR SIGNAUX NON-STATIONNAIRES ET STRUCTURES(2016), European Project, Centre National de la Recherche Scientifique (CNRS)-École normale supérieure - Lyon (ENS Lyon), École normale supérieure - Lyon (ENS Lyon)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut National de Recherche en Informatique et en Automatique (Inria)-Centre National de la Recherche Scientifique (CNRS)-École normale supérieure - Lyon (ENS Lyon)-Université Claude Bernard Lyon 1 (UCBL), Université Toulouse 1 Capitole ( UT1 ) -Université Toulouse - Jean Jaurès ( UT2J ) -Université Toulouse III - Paul Sabatier ( UPS ), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-PRES Université de Toulouse-Institut National des Sciences Appliquées - Toulouse ( INSA Toulouse ), and Institut National des Sciences Appliquées ( INSA ) -Institut National des Sciences Appliquées ( INSA ) -Centre National de la Recherche Scientifique ( CNRS )

Subjects
FOS: Computer and information sciences, Computer Science - Learning, [STAT.ML]Statistics [stat]/Machine Learning [stat.ML], Statistics - Machine Learning, multi-armed bandits, Machine Learning (stat.ML), [ STAT.ML ] Statistics [stat]/Machine Learning [stat.ML], Machine Learning (cs.LG), sequential adaptive hypothesis testing
Abstract

International audience; Learning the minimum/maximum mean among a finite set of distributions is a fundamental sub-task in planning, game tree search and reinforcement learning. We formalize this learning task as the problem of sequentially testing how the minimum mean among a finite set of distributions compares to a given threshold. We develop refined non-asymptotic lower bounds, which show that optimality mandates very different sampling behavior for a low vs high true minimum. We show that Thompson Sampling and the intuitive Lower Confidence Bounds policy each nail only one of these cases. We develop a novel approach that we call Murphy Sampling. Even though it entertains exclusively low true minima, we prove that MS is optimal for both possibilities. We then design advanced self-normalized deviation inequalities, fueling more aggressive stopping rules. We complement our theoretical guarantees by experiments showing that MS works best in practice.

Published
2018

84. Prognostic model for high-tumor-burden follicular lymphoma integrating baseline and end-induction PET: a LYSA/FIL study

Author

Corinne Haioun, Judith Trotman, Gilles Salles, Stefano Luminari, Loïc Chartier, Hervé Tilly, Michel Meignan, Rene-Olivier Casasnovas, Jehan Dupuis, Massimo Menga, Vittoria Tarantino, Annibale Versari, Massimo Federico, Alina Berriolo-Riedinger, Anne-Ségolène Cottereau, Hôpital Henri Mondor, Assistance publique - Hôpitaux de Paris (AP-HP)-Hôpital Henri Mondor-Université Paris-Est Créteil Val-de-Marne - Paris 12 ( UPEC UP12 ), Service de médecine nucléaire [AP-HP Hôpital Cochin], CHU Cochin [AP-HP], IRCCS-Arcispedale Santa Maria Nuova, Reggio Emilia, Institut de Mathématiques de Toulouse UMR5219 ( IMT ), 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 ) -PRES Université de Toulouse-Université Paul Sabatier - Toulouse 3 ( UPS ) -Université Toulouse - Jean Jaurès ( UT2J ) -Université Toulouse 1 Capitole ( UT1 ), Epidémiologie des Maladies Emergentes, Conservatoire National des Arts et Métiers [CNAM] ( CNAM ) -Institut Pasteur [Paris]-Pasteur-Cnam risques infectieux et émergents ( PACRI ), Institut Pasteur [Paris]-Conservatoire National des Arts et Métiers [CNAM] : EA4628-Conservatoire National des Arts et Métiers [CNAM] : EA4628, Centre Hospitalier Universitaire de Dijon - Hôpital François Mitterrand ( CHU Dijon ), Centre Régional de Lutte contre le cancer - Centre Georges-François Leclerc ( CRLCC - CGFL ), Service d'hématologie clinique, Groupe d'étude des proliférations lymphoïdes ( GPL ), Université de Rouen Normandie ( UNIROUEN ), Normandie Université ( NU ) -Normandie Université ( NU ) -Institut National de la Santé et de la Recherche Médicale ( INSERM ), Department of Oncology and Hematology, University of Modena and Reggio Emilia, Centre Hospitalier Lyon Sud [CHU - HCL] ( CHLS ), Hospices Civils de Lyon ( HCL ), Concord Repatriation General Hospital, Service de médecine nucléaire [Créteil], Assistance publique - Hôpitaux de Paris (AP-HP) (APHP)-Hôpital Henri Mondor-Université Paris-Est Créteil Val-de-Marne - Paris 12 (UPEC UP12), Institut de Mathématiques de Toulouse UMR5219 (IMT), Université Toulouse 1 Capitole (UT1)-Université Toulouse - Jean Jaurès (UT2J)-Université Toulouse III - Paul Sabatier (UPS), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-PRES Université de Toulouse-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS), Centre Hospitalier Lyon Sud [CHU - HCL] (CHLS), Hospices Civils de Lyon (HCL), Centre Hospitalier Universitaire de Dijon - Hôpital François Mitterrand (CHU Dijon), Centre Régional de Lutte contre le cancer - Centre Georges-François Leclerc (CRLCC - CGFL), Groupe d'étude des proliférations lymphoïdes (GPL), Université de Rouen Normandie (UNIROUEN), Normandie Université (NU)-Normandie Université (NU)-Institut National de la Santé et de la Recherche Médicale (INSERM), and Università degli Studi di Modena e Reggio Emilia (UNIMORE)

Subjects
Male, 0301 basic medicine, Oncology, medicine.medical_specialty, Biochemistry, Immunology, Hematology, Cell Biology, Population, Follicular lymphoma, [SDV.CAN]Life Sciences [q-bio]/Cancer, Models, Biological, Disease-Free Survival, [ SDV.CAN ] Life Sciences [q-bio]/Cancer, 03 medical and health sciences, 0302 clinical medicine, Median follow-up, Internal medicine, medicine, Humans, Prospective Studies, Risk factor, education, Prospective cohort study, Lymphoma, Follicular, Aged, education.field_of_study, business.industry, Hazard ratio, Middle Aged, Prognosis, medicine.disease, Confidence interval, Tumor Burden, Lymphoma, 030104 developmental biology, Positron-Emission Tomography, 030220 oncology & carcinogenesis, Multivariate Analysis, Disease Progression, Female, business
Abstract

International audience; Both total metabolic tumor volume (TMTV), computed on baseline positron emission tomography (PET), and end of induction (EOI) PET are imaging biomarkers showing promise for early risk stratification in patients with high-tumor-burden follicular lymphoma. A model was built incorporating these 2 factors in 159 patients from three prospective trials: 2 Lymphoma Study Association (LYSA) studies and 1 Fondazione Italiana Linfomi (FIL) trial. Median follow up was 64 months. High TMTV (>510 cm3) and positive EOI PET were independent, significant risk factors for progression. Their combination stratified the population into 3 risk groups: patients with no risk factors (n = 102; 64%) had a 5-year progression-free survival (PFS) of 67% vs 33% (hazard ratio [HR], 2.9; 95% confidence interval [CI], 1.8-4.9) for patients with 1 risk factor (n = 44; 27%) and only 23% (HR, 4.6; 95% CI, 2.3-9.2) for patients with both risk factors (n = 13; 8%). 2-year PFS was respectively 90% vs 61% (HR, 4.8; 95% CI, 2.2-10.4) and 46% (HR, 8.1; 95%CI, 3.1-21.3). This model enhances the prognostic value of PET staging and response assessment, identifying a subset of patients with a very high risk of progression and early treatment failure at 2 years.

Published
2018
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85. Shapley effects for sensitivity analysis with correlated inputs: comparisons with Sobol' indices, numerical estimation and applications

Author

Bertrand Iooss, Clémentine Prieur, 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 1 Capitole ( UT1 ) -Université Toulouse - Jean Jaurès ( UT2J ) -Université Toulouse III - Paul Sabatier ( UPS ), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-PRES Université de Toulouse-Institut National des Sciences Appliquées - Toulouse ( INSA Toulouse ), Institut National des Sciences Appliquées ( INSA ) -Institut National des Sciences Appliquées ( INSA ) -Centre National de la Recherche Scientifique ( CNRS ), EDF ( EDF ), Mathematics and computing applied to oceanic and atmospheric flows ( AIRSEA ), Inria Grenoble - Rhône-Alpes, Institut National de Recherche en Informatique et en Automatique ( Inria ) -Institut National de Recherche en Informatique et en Automatique ( Inria ) -Laboratoire Jean Kuntzmann ( LJK ), Université Pierre Mendès France - Grenoble 2 ( UPMF ) -Université Joseph Fourier - Grenoble 1 ( UJF ) -Institut Polytechnique de Grenoble - Grenoble Institute of Technology-Centre National de la Recherche Scientifique ( CNRS ) -Université Grenoble Alpes ( UGA ) -Université Pierre Mendès France - Grenoble 2 ( UPMF ) -Université Joseph Fourier - Grenoble 1 ( UJF ) -Institut Polytechnique de Grenoble - Grenoble Institute of Technology-Centre National de la Recherche Scientifique ( CNRS ) -Université Grenoble Alpes ( UGA ) -Institut National Polytechnique de Grenoble ( INPG ), Institut polytechnique de Grenoble - Grenoble Institute of Technology ( Grenoble INP ) -Université Grenoble Alpes ( UGA ) -Laboratoire Jean Kuntzmann ( LJK ), Université Pierre Mendès France - Grenoble 2 ( UPMF ) -Université Joseph Fourier - Grenoble 1 ( UJF ) -Institut Polytechnique de Grenoble - Grenoble Institute of Technology-Centre National de la Recherche Scientifique ( CNRS ) -Université Grenoble Alpes ( UGA ) -Université Pierre Mendès France - Grenoble 2 ( UPMF ) -Université Joseph Fourier - Grenoble 1 ( UJF ) -Institut Polytechnique de Grenoble - Grenoble Institute of Technology-Centre National de la Recherche Scientifique ( CNRS ) -Inria Grenoble - Rhône-Alpes, Institut National de Recherche en Informatique et en Automatique ( Inria ) -Institut National de Recherche en Informatique et en Automatique ( Inria ), Performance, Risque Industriel, Surveillance pour la Maintenance et l’Exploitation (EDF R&D PRISME), EDF R&D (EDF R&D), EDF (EDF)-EDF (EDF), Institut de Mathématiques de Toulouse UMR5219 (IMT), 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), Méthodes d'Analyse Stochastique des Codes et Traitements Numériques (GdR MASCOT-NUM), Centre National de la Recherche Scientifique (CNRS), Mathematics and computing applied to oceanic and atmospheric flows (AIRSEA), Institut National de Recherche en Informatique et en Automatique (Inria)-Institut National de Recherche en Informatique et en Automatique (Inria)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Laboratoire Jean Kuntzmann (LJK ), Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut National de Recherche en Informatique et en Automatique (Inria)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Centre National de la Recherche Scientifique (CNRS), 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 National de la Recherche Scientifique (CNRS)-PRES Université de Toulouse-Université Toulouse III - Paul Sabatier (UPS), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Université Toulouse - Jean Jaurès (UT2J)-Université Toulouse 1 Capitole (UT1), Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Université Grenoble Alpes (UGA)-Laboratoire Jean Kuntzmann (LJK), Université Pierre Mendès France - Grenoble 2 (UPMF)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut Polytechnique de Grenoble - Grenoble Institute of Technology-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Université Pierre Mendès France - Grenoble 2 (UPMF)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut Polytechnique de Grenoble - Grenoble Institute of Technology-Centre National de la Recherche Scientifique (CNRS)-Inria Grenoble - Rhône-Alpes, and Institut National de Recherche en Informatique et en Automatique (Inria)-Institut National de Recherche en Informatique et en Automatique (Inria)

Subjects
Statistics and Probability, Control and Optimization, Gaussian, Computer experiments, 0211 other engineering and technologies, Mathematics - Statistics Theory, 02 engineering and technology, 030226 pharmacology & pharmacy, Sobol' indices, Sobol', Interpretation (model theory), Variance contribution, 03 medical and health sciences, symbols.namesake, 0302 clinical medicine, [MATH.MATH-ST]Mathematics [math]/Statistics [math.ST], Kriging, Metamodel, Discrete Mathematics and Combinatorics, Applied mathematics, Sensitivity (control systems), [ MATH.MATH-ST ] Mathematics [math]/Statistics [math.ST], Uncertainty quantification, Shapley effects, Dependence, Mathematics, 021110 strategic, defence & security studies, Sobol sequence, Shapley, Computer experiment, Variable (computer science), Sensitivity Analysis, Modeling and Simulation, symbols, Uncertainty Quantification
Abstract

The global sensitivity analysis of a numerical model aims to quantify, by means of sensitivity indices estimate, the contributions of each uncertain input variable to the model output uncertainty. The so-called Sobol' indices, which are based on the functional variance analysis, present a difficult interpretation in the presence of statistical dependence between inputs. The Shapley effect was recently introduced to overcome this problem as they allocate the mutual contribution (due to correlation and interaction) of a group of inputs to each individual input within the group.In this paper, using several new analytical results, we study the effects of linear correlation between some Gaussian input variables on Shapley effects, and compare these effects to classical first-order and total Sobol' indices.This illustrates the interest, in terms of sensitivity analysis setting and interpretation, of the Shapley effects in the case of dependent inputs. We also investigate the numerical convergence of the estimated Shapley effects. For the practical issue of computationally demanding computer models, we show that the substitution of the original model by a metamodel (here, kriging) makes it possible to estimate these indices with precision at a reasonable computational cost.

Published
2018
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86. OPTIMAL CONVERGENCE RATES FOR NESTEROV ACCELERATION

Author

Jean-François Aujol, Charles Dossal, Aude Rondepierre, Institut de Mathématiques de Bordeaux ( IMB ), 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 ), Institut de Mathématiques de Toulouse UMR5219 ( IMT ), Université Toulouse 1 Capitole ( UT1 ) -Université Toulouse - Jean Jaurès ( UT2J ) -Université Toulouse III - Paul Sabatier ( UPS ), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-PRES Université de Toulouse-Institut National des Sciences Appliquées - Toulouse ( INSA Toulouse ), Institut National des Sciences Appliquées ( INSA ) -Institut National des Sciences Appliquées ( INSA ) -Centre National de la Recherche Scientifique ( CNRS ), Équipe Recherche Opérationnelle, Optimisation Combinatoire et Contraintes ( LAAS-ROC ), Laboratoire d'analyse et d'architecture des systèmes [Toulouse] ( LAAS ), Institut National Polytechnique [Toulouse] ( INP ) -Institut National des Sciences Appliquées - Toulouse ( INSA Toulouse ), Institut National des Sciences Appliquées ( INSA ) -Institut National des Sciences Appliquées ( INSA ) -Université Toulouse III - Paul Sabatier ( UPS ), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique ( CNRS ) -Institut National Polytechnique [Toulouse] ( INP ) -Institut National des Sciences Appliquées - Toulouse ( INSA Toulouse ), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique ( CNRS ), Institut de Mathématiques de Bordeaux (IMB), 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), Institut de Mathématiques de Toulouse UMR5219 (IMT), Université Toulouse 1 Capitole (UT1)-Université Toulouse - Jean Jaurès (UT2J)-Université Toulouse III - Paul Sabatier (UPS), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-PRES Université de Toulouse-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS), Équipe Recherche Opérationnelle, Optimisation Combinatoire et Contraintes (LAAS-ROC), Laboratoire d'analyse et d'architecture des systèmes [Toulouse] (LAAS), Centre National de la Recherche Scientifique (CNRS)-Université Toulouse III - Paul Sabatier (UPS), 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)-Institut National Polytechnique [Toulouse] (INP)-Centre National de la Recherche Scientifique (CNRS)-Université Toulouse III - Paul Sabatier (UPS), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Institut National Polytechnique [Toulouse] (INP), 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), 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 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 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), 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
Lyapunov function, [ MATH.MATH-OC ] Mathematics [math]/Optimization and Control [math.OC], Work (thermodynamics), 0211 other engineering and technologies, Acceleration (differential geometry), 010103 numerical & computational mathematics, 02 engineering and technology, 01 natural sciences, Theoretical Computer Science, symbols.namesake, Convergence (routing), FOS: Mathematics, Applied mathematics, ODEs, 0101 mathematics, Mathematics - Optimization and Control, Mathematics, Lyapunov functions, 021103 operations research, Lojasiewicz property, Ode, Function (mathematics), Computer Science::Numerical Analysis, Rate of convergence, Optimization and Control (math.OC), symbols, [MATH.MATH-OC]Mathematics [math]/Optimization and Control [math.OC], Convex function, optimization, Software, rate of convergence
Abstract

International audience; In this paper, we study the behavior of solutions of the ODE associated to Nesterov acceleration. It is well-known since the pioneering work of Nesterov that the rate of convergence $O(1/t^2)$ is optimal for the class of convex functions with Lipschitz gradient. In this work, we show that better convergence rates can be obtained with some additional geometrical conditions, such as \L ojasiewicz property. More precisely, we prove the optimal convergence rates that can be obtained depending on the geometry of the function $F$ to minimize. The convergence rates are new, and they shed new light on the behavior of Nesterov acceleration schemes. We prove in particular that the classical Nesterov scheme may provide convergence rates that are worse than the classical gradient descent scheme on sharp functions: for instance, the convergence rate for strongly convex functions is not geometric for the classical Nesterov scheme (while it is the case for the gradient descent algorithm). This shows that applying the classical Nesterov acceleration on convex functions without looking more at the geometrical properties of the objective functions may lead to sub-optimal algorithms.

Published
2018
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87. Global Model of Plasmaspheric Hiss from Multiple Satellite Observations

Author

Tobias Kersten, Jacob Bortnik, Nigel P. Meredith, Angélica Sicard, Richard B. Horne, Keith H. Yearby, Wen Li, British Antarctic Survey (BAS), Natural Environment Research Council (NERC), Center for Space Physics [Boston] (CSP), Boston University [Boston] (BU), Department of Atmospheric and Oceanic Sciences [Los Angeles] (AOS), University of California [Los Angeles] (UCLA), University of California-University of California, ONERA / DPHY, Université de Toulouse [Toulouse], PRES Université de Toulouse-ONERA, Department of Automatic Control and Systems Engineering [ Sheffield] (ACSE), University of Sheffield [Sheffield], and ONERA-PRES Université de Toulouse

Subjects
Hiss, 010504 meteorology & atmospheric sciences, Magnetosphere, Plasmasphere, 02 engineering and technology, 010502 geochemistry & geophysics, 01 natural sciences, Electronic mail, MODELE, symbols.namesake, 0202 electrical engineering, electronic engineering, information engineering, Van Allen Probes, Pitch angle, 0105 earth and related environmental sciences, Wave power, ONDES, [SPI.PLASMA]Engineering Sciences [physics]/Plasmas, 020206 networking & telecommunications, Geophysics, [PHYS.PHYS.PHYS-SPACE-PH]Physics [physics]/Physics [physics]/Space Physics [physics.space-ph], Earth's magnetic field, Space and Planetary Science, 13. Climate action, Van Allen radiation belt, Physics::Space Physics, symbols, Astrophysics::Earth and Planetary Astrophysics, Geology
Abstract

International audience; We present a global model of plasmaspheric hiss, using data from eight satellites, extending the coverage and improving the statistics of existing models. We use geomagnetic activity dependent templates to separate plasmaspheric hiss from chorus. In the region 22–14 magnetic local time (MLT) the boundary between plasmaspheric hiss and chorus moves to lower values with increasing geomagnetic activity. The average wave intensity of plasmaspheric hiss is largest on the dayside and increases with increasing geomagnetic activity from midnight through dawn to dusk. Plasmaspheric hiss is most intense and spatially extended in the 200 to 500 Hz frequency band during active conditions, 400

Published
2018
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88. A Physical Model of the Proton Radiation Belts of Jupiter inside Europa's Orbit

Author

Stephan P. A. Sauer, Henry B. Garrett, Angélica Sicard, Quentin Nénon, Peter Kollmann, Chris Paranicas, ONERA / DPHY, Université de Toulouse [Toulouse], ONERA-PRES Université de Toulouse, Johns Hopkins University Applied Physics Laboratory [Laurel, MD] (APL), Jet Propulsion Laboratory (JPL), NASA-California Institute of Technology (CALTECH), Department of Chemistry [Copenhagen], Faculty of Science [Copenhagen], University of Copenhagen = Københavns Universitet (KU)-University of Copenhagen = Københavns Universitet (KU), and PRES Université de Toulouse-ONERA

Subjects
Physics, 010504 meteorology & atmospheric sciences, Astronomy, EUROPA’S ORBIT, 7. Clean energy, 01 natural sciences, [PHYS.PHYS.PHYS-SPACE-PH]Physics [physics]/Physics [physics]/Space Physics [physics.space-ph], Proton (rocket family), Jupiter, PROTON RADIATION BELTS OF JUPITER, symbols.namesake, Geophysics, Proton radiation, SALAMMBO MODEL, Space and Planetary Science, [SDU]Sciences of the Universe [physics], Van Allen radiation belt, 0103 physical sciences, Physics::Space Physics, symbols, Astrophysics::Earth and Planetary Astrophysics, Orbit (control theory), Nuclear Experiment, 010303 astronomy & astrophysics, 0105 earth and related environmental sciences
Abstract

International audience; A physical model of the Jovian trapped protons with kinetic energies higher than 1 MeV inward of the orbit of the icy moon Europa is presented. The model, named Salammbô, takes into account the radial diffusion process, the absorption effect of the Jovian moons, and the Coulomb collisions and charge exchanges with the cold plasma and neutral populations of the inner Jovian magnetosphere. Preliminary modeling of the wave‐particle interaction with electromagnetic ion cyclotron waves near the moon Io is also performed. Salammbô is validated against in situ proton measurements of Pioneer 10, Pioneer 11, Voyager 1, Galileo Probe, and Galileo Orbiter. A prominent feature of the MeV proton intensity distribution in the modeled area is the 2 orders of magnitude flux depletion observed in MeV measurements near the orbit of Io. Our simulations reveal that this is not due to direct interactions with the moon or its neutral environment but results from scattering of the protons by electromagnetic ion cyclotron waves.

Published
2018
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89. High-Energy Electrons in the Inner Zone

Author

Daniel Boscher, S. Bourdarie, Vincent Maget, A. Sicard-Piet, Denis Standarovski, G. Rolland, ONERA / DPHY, Université de Toulouse [Toulouse], ONERA-PRES Université de Toulouse, ONERA - The French Aerospace Lab [Toulouse], ONERA, Centre National d'Études Spatiales [Toulouse] (CNES), and PRES Université de Toulouse-ONERA

Subjects
Physics, Proton channel, Nuclear and High Energy Physics, High energy, 010504 meteorology & atmospheric sciences, 020206 networking & telecommunications, 02 engineering and technology, Electron, 7. Clean energy, 01 natural sciences, RADIATION BELTS, Magnetic flux, [PHYS.PHYS.PHYS-SPACE-PH]Physics [physics]/Physics [physics]/Space Physics [physics.space-ph], Computational physics, [SPI.TRON]Engineering Sciences [physics]/Electronics, symbols.namesake, Nuclear Energy and Engineering, CEINTURE RADIATION, Van Allen radiation belt, 0202 electrical engineering, electronic engineering, information engineering, symbols, ELECTRON, Electrical and Electronic Engineering, 0105 earth and related environmental sciences
Abstract

International audience; The existence of high energy (E>1 MeV) electrons in the inner zone is always a debate issue. This study aims at answering this question using both simulation-based and data measurements evidences. First, using NOAA measurements and in particular a proton channel contaminated by E>1.2MeV electrons, the slot filling was studied over solar cycles. Then the found profiles were compared to the CRRES and SAMPEX measurements. Finally, using a simplistic physical model derived from Salammbô, the variations were estimated to understand the long term behavior of the electrons in the inner belt.; L'existence d'électrons de haute énergie (E> 1 MeV) dans la zone interne est toujours un sujet de débat. Cette étude vise à répondre à cette question en utilisant à la fois des preuves basées sur la simulation et des données de mesure. Tout d'abord, en utilisant des mesures NOAA et en particulier un canal proton contaminé par des électrons E> 1,2 MeV, le remplissage de la région du Slot a été étudié sur plusieurs cycles solaires. Ensuite, les profils trouvés ont été comparés aux mesures CRRES et SAMPEX. Enfin, en utilisant un modèle physique simpliste dérivé de Salammbô, les variations ont été estimées pour comprendre le comportement à long terme des électrons dans la ceinture intérieure.

Published
2018
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90. Well-suited and adaptive post-processing for the visualization of hp simulation results

Author

Christophe Besse, Vincent Mouysset, Matthieu Maunoury, Pol-André Haas, Sébastien Pernet, ONERA - The French Aerospace Lab ( Toulouse ), ONERA, Institut de Mathématiques de Toulouse UMR5219 ( IMT ), 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 ) -PRES Université de Toulouse-Université Paul Sabatier - Toulouse 3 ( UPS ) -Université Toulouse - Jean Jaurès ( UT2J ) -Université Toulouse 1 Capitole ( UT1 ), ONERA / DTIS, Université de Toulouse [Toulouse], ONERA-PRES Université de Toulouse, Institut de Mathématiques de Toulouse UMR5219 (IMT), 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 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
Physics and Astronomy (miscellaneous), Computer science, 010103 numerical & computational mathematics, 01 natural sciences, high-order finite element, Discontinuous Galerkin method, 0101 mathematics, Representation (mathematics), Visualization, Pointwise, Software visualization, Numerical Analysis, Applied Mathematics, Numerical analysis, post-processing, [ MATH.MATH-NA ] Mathematics [math]/Numerical Analysis [math.NA], Finite element method, Computer Science Applications, 010101 applied mathematics, Computational Mathematics, Modeling and Simulation, A priori and a posteriori, Algorithm, [MATH.MATH-NA]Mathematics [math]/Numerical Analysis [math.NA], discontinuous Galerkin
Abstract

International audience; While high order methods became very popular as they allow to perform very accurate solutions with low computational time and memory cost, there is a lack of tools to visualize and post-treat the solutions given by these methods. Originally, visualization softwares were developed to post-process results from methods such that finite differences or usual finite elements and therefore process linear primitives. In this paper, we present a methodology to visualize results of high order methods. Our approach is based on the construction of an optimized affine approximation of the high order solution which can therefore be handled by any visualization software. A representation mesh is constructed and the process is guided by an a posteriori estimate which control the error between the numerical solution and its representation pointwise. This point by point control is crucial as under their picture form, data correspond to values mapped on elements where anyone can pick up a pointwise information. A strategy is established to ensure that discontinuities are well represented. These discontinuities come either from the physical problem (material change) or the numerical method (discontinuous Galerkin method) and are pictured accurately. Several numerical examples are presented to demonstrate the potential of the method.

Published
2018
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91. Accurate, Automatic and Compressed Visualization of Radiated Helmholtz Fields from Boundary Element Solutions

Author

Maunoury , Matthieu, Besse , Christophe, Mouysset , Vincent, Pernet , Sébastien, ONERA - The French Aerospace Lab ( Toulouse ), ONERA, Institut de Mathématiques de Toulouse UMR5219 ( IMT ), 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 ) -PRES Université de Toulouse-Université Paul Sabatier - Toulouse 3 ( UPS ) -Université Toulouse - Jean Jaurès ( UT2J ) -Université Toulouse 1 Capitole ( UT1 ), ONERA / DTIS, Université de Toulouse [Toulouse], ONERA-PRES Université de Toulouse, 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 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), and Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)

Subjects
visualisation, integral representation formulas, high order reconstruction, méthode des éléments de frontière, reconstruction d'ordre élevé, directional interpolation, Boundary Equation Methods, [ MATH.MATH-NA ] Mathematics [math]/Numerical Analysis [math.NA], interpolation directionnelle, [MATH.MATH-NA]Mathematics [math]/Numerical Analysis [math.NA], visualization, formule de représentation intégrale
Abstract

International audience; We propose a methodology to generate an accurate and efficient reconstruction of radiated fields based on high order interpolation. As the solution is obtained with the convolution by a smooth but potentially high frequency oscillatory kernel, our basis functions therefore incorporate plane waves. Directional interpolation is shown to be efficient for smart directions. An adaptive subdivision of the domain is established to limit the oscillations of the kernel in each element. The new basis functions , combining high order polynomials and plane waves, provide much better accuracy than low order ones. Finally, as standard visualization softwares are generally unable to represent such fields, a method to have a well-suited visualization of high order functions is used. Several numerical results confirm the potential of the method.; Nous proposons une méthodologie pour générer la reconstruction précise et efficace des champs rayonnés à partir d'interpolations d'ordre élevé. Comme la solution est obtenue par convolution avec un noyau régulier mais potentiellement oscillant à hautes fréquences, nos fonctions de base incorporent donc des ondes planes. Nous montrons que l'interpolation directionnelle est efficace pour les bonnes directions. Une subdivision adaptative du domaine est créée afin de limiter les oscillations du noyau dans chaque élément. Les nouvelles fonctions de base, combinant des polynômes d'ordre élevé et des ondes planes, donnent une bien meilleure précision que celles de bas ordre. Enfin, les logiciels de visualisation étant généralement incapables de représenter de telles solutions, une méthode permettant une visualisation correcte des fonctions d'ordre élevé est utilisée. Plusieurs exemples numériques confirment le potentiel de cette méthode.

Published
2018
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92. Gamma non-ionizing energy loss: Comparison with the damage factor in silicon devices

Author

I. Zorkani, E. El Allam, A. Meulenberg, A. Jorio, Christophe Inguimbert, Université Sidi Mohamed Ben Abdellah (USMBA), ONERA / DPHY, Université de Toulouse [Toulouse], ONERA-PRES Université de Toulouse, The Science for Humanity Trust Inc., and PRES Université de Toulouse-ONERA

Subjects
Energy loss, Silicon, DISPLACEMENT DAMAGE DOSE, General Physics and Astronomy, chemistry.chemical_element, Damage factor, DOSE DE DOMMAGE DE DEPLACEMENT, 02 engineering and technology, 01 natural sciences, Fluence, EFFET DES RADIATIONS, 0103 physical sciences, Thermal, Scaling, NIEL, Physics, 010308 nuclear & particles physics, RADIATION EFFECT, [SPI.NRJ]Engineering Sciences [physics]/Electric power, Gamma ray, 021001 nanoscience & nanotechnology, Non-ionizing radiation, [PHYS.PHYS.PHYS-SPACE-PH]Physics [physics]/Physics [physics]/Space Physics [physics.space-ph], Computational physics, [SPI.TRON]Engineering Sciences [physics]/Electronics, chemistry, 0210 nano-technology
Abstract

International audience; The concept of non-ionizing energy loss (NIEL) has been demonstrated to be a successful approach to describe the displacement damage effects in silicon materials and devices. However, some discrepancies exist in the literature between experimental damage factors and theoretical NIELs. 60Co gamma rays having a low NIEL are an interesting particle source that can be used to validate the NIEL scaling approach. This paper presents different 60Co gamma ray NIEL values for silicon targets. They are compared with the radiation-induced increase in the thermal generation rate of carriers per unit fluence. The differences between the different models, including one using molecular dynamics, are discussed.

Published
2018
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93. 3D streamers simulation in a pin to plane configuration using massively parallel computing

Author

Carolyn Jacobs, Nicolas Renon, Mohammed Yousfi, O. Ducasse, Philippe Dessante, Olivier Eichwald, J.M. Plewa, Laboratoire Génie électrique et électronique de Paris ( GeePs ), Centre National de la Recherche Scientifique ( CNRS ) -CentraleSupélec-Université Pierre et Marie Curie - Paris 6 ( UPMC ) -Université Paris-Sud - Paris 11 ( UP11 ), LAboratoire PLasma et Conversion d'Energie ( LAPLACE ), Institut National Polytechnique [Toulouse] ( INP ) -Université Paul Sabatier - Toulouse 3 ( UPS ) -Centre National de la Recherche Scientifique ( CNRS ), Laboratoire Génie électrique et électronique de Paris (GeePs), Université Paris-Sud - Paris 11 (UP11)-Université Pierre et Marie Curie - Paris 6 (UPMC)-CentraleSupélec-Centre National de la Recherche Scientifique (CNRS), LAboratoire PLasma et Conversion d'Energie (LAPLACE), Centre National de la Recherche Scientifique (CNRS)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées, Plasmas Réactifs Hors Equilibre (LAPLACE-PRHE), Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Université Toulouse III - Paul Sabatier (UT3), Calcul en Midi-Pyrénées (CALMIP), 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 Fédérale Toulouse Midi-Pyrénées-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-PRES Université de Toulouse, Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-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 III - Paul Sabatier (UT3), and Centre National de la Recherche Scientifique (CNRS)-PRES Université de Toulouse-Université Toulouse III - Paul Sabatier (UT3)

Subjects
010302 applied physics, Finite volume method, Acoustics and Ultrasonics, Computer science, [SPI.PLASMA]Engineering Sciences [physics]/Plasmas, Message Passing Interface, Condensed Matter Physics, Supercomputer, 01 natural sciences, 010305 fluids & plasmas, Surfaces, Coatings and Films, Electronic, Optical and Magnetic Materials, Computational science, Biconjugate gradient stabilized method, 0103 physical sciences, Benchmark (computing), Poisson's equation, [ SPI.PLASMA ] Engineering Sciences [physics]/Plasmas, Massively parallel, Corona discharge, ComputingMilieux_MISCELLANEOUS
Abstract

International audience; This paper concerns the 3D simulation of corona discharge using high performance computing (HPC) managed with the message passing interface (MPI) library. In the field of finite volume methods applied on non-adaptive mesh grids and in the case of a specific 3D dynamic benchmark test devoted to streamer studies, the great efficiency of the iterative R&B SOR and BiCGSTAB methods versus the direct MUMPS method was clearly demonstrated in solving the Poisson equation using HPC resources. The optimization of the parallelization and the resulting scalability was undertaken as a function of the HPC architecture for a number of mesh cells ranging from 8 to 512 million and a number of cores ranging from 20 to 1600. The R&B SOR method remains at least about four times faster than the BiCGSTAB method and requires significantly less memory for all tested situations. The R&B SOR method was then implemented in a 3D MPI parallelized code that solves the classical first order model of an atmospheric pressure corona discharge in air. The 3D code capabilities were tested by following the development of one, two and four coplanar streamers generated by initial plasma spots for 6 ns. The preliminary results obtained allowed us to follow in detail the formation of the tree structure of a corona discharge and the effects of the mutual interactions between the streamers in terms of streamer velocity, trajectory and diameter. The computing time for 64 million of mesh cells distributed over 1000 cores using the MPI procedures is about 30 min ns−1, regardless of the number of streamers.

Published
2018
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94. NOIRE study report: Towards a low frequency radio interferometer in space

Author

Albert-Jan Boonstra, Mickael Bruno, Mark J. Bentum, Patrick Gélard, Alain Lamy, Julien N. Girard, Baptiste Cecconi, Quentin Nénon, Michel Delpech, Jean-Mathias Grießmeier, Moustapha Dekkali, Carine Briand, David Valat, Boris Segret, Martin Bucher, Andre Laurens, Laboratoire d'études spatiales et d'instrumentation en astrophysique (LESIA), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), CEA Sorbonne Paris Cité, Centre National d'Études Spatiales [Toulouse] (CNES), AstroParticule et Cosmologie (APC (UMR_7164)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Observatoire de Paris, ONERA / DPHY, Université de Toulouse [Toulouse], ONERA-PRES Université de Toulouse, Laboratoire de Physique et Chimie de l'Environnement et de l'Espace (LPC2E), Observatoire des Sciences de l'Univers en région Centre (OSUC), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Centre National d’Études Spatiales [Paris] (CNES), Unité Scientifique de la Station de Nançay (USN), Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS), Netherlands Institute for Radio Astronomy (ASTRON), Eindhoven Technical University, Université Paris Diderot, Sorbonne Paris Cité, Paris, France, Université Paris Diderot - Paris 7 (UPD7), PRES Université de Toulouse-ONERA, Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université d'Orléans (UO)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université d'Orléans (UO)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National d’Études Spatiales [Paris] (CNES), Centre National de la Recherche Scientifique (CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire des Sciences de l'Univers en région Centre (OSUC), Université Paris sciences et lettres (PSL)-Université d'Orléans (UO), Electromagnetics, Center for Wireless Technology Eindhoven, EM for Radio Science Lab, Laboratoire d'études spatiales et d'instrumentation en astrophysique = Laboratory of Space Studies and Instrumentation in Astrophysics (LESIA), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité), Astrophysique Interprétation Modélisation (AIM (UMR_7158 / UMR_E_9005 / UM_112)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité), and Technische Universiteit Eindhoven (TU/e)

Subjects
[PHYS.ASTR.IM]Physics [physics]/Astrophysics [astro-ph]/Instrumentation and Methods for Astrophysic [astro-ph.IM], Computer science, business.industry, Electrical engineering, Electromagnetic compatibility, FOS: Physical sciences, Magnetosphere, Lagrangian point, Ranging, Orbit of the Moon, 7. Clean energy, 01 natural sciences, Clock synchronization, Interferometry, Observatory, [SDU]Sciences of the Universe [physics], 0103 physical sciences, Astronomical interferometer, 010306 general physics, business, Astrophysics - Instrumentation and Methods for Astrophysics, Instrumentation and Methods for Astrophysics (astro-ph.IM), 010303 astronomy & astrophysics
Abstract

Ground based low frequency radio interferometers have been developed in the last decade and are providing the scientific community with high quality observations. Conversely, current radioastronomy instruments in space have a poor angular resolution with single point observation systems. Improving the observation capabilities of the low frequency range (a few kHz to 100 MHz) requires to go to space and to set up a space based network of antenna that can be used as an interferometer. We present the outcome of the NOIRE (Nanosatellites pour un Observatoire Interf\'erom\'etrique Radio dans l'Espace / Nanosatellites for a Radio Interferometer Observatory in Space) study which assessed, with help of CNES PASO (Architecture Platform for Orbital Systems is CNES' cross-disciplinary team in charge of early mission and concept studies), the feasibility of a swarm of nanosatellites dedicated to a low frequency radio observatory. With such a platform, space system engineering and instrument development must be studied as a whole: each node is a sensor and all sensors must be used together to obtain a measurement. The study was conducted on the following topics: system principle and concept (swarm, node homogeneity); Space and time management (ranging, clock synchronization); Orbitography (Moon orbit, Lagrange point options); Telecommunication (between nodes and with ground) and networking; Measurements and processing; Propulsion; Power; Electromagnetic compatibility. No strong show-stopper was identified during the preliminary study, although the concept is not yet ready. Several further studies and milestones are identified. The NOIRE team will collaborate with international teams to try and build this next generation of space systems., Comment: Submitted to IEEEAeroconf 2018 proceedings

Published
2018
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95. Cardiac Rhythm Disturbances in Hemodialysis Patients

Author

Sébastien Buffler, Yahsou Delmas, Michel Haïssaguerre, Christian Combe, Cécile Vigneau, Nicolas Klotz, Antoine Bénard, Valerie De Precigout, Jean-Baptiste Gourraud, Antoine Deplagne, Philippe Ritter, Philippe Mabo, Dorothée Bazin-kara, Atman Haddj-Elmrabet, Bruno Seigneuric, Sylvain Ploux, Adrien Keller, Jean-Philippe Bourdenx, Laurence Jesel, Helene Savel, Claire Borni-Duval, Claire A. Martin, Philippe Maury, Frederic Sacher, Thierry Hannedouche, Sylvain Reuter, Virginie Rondeau, Pierre Bordachar, Frédéric Lavainne, J. Ott, IHU-LIRYC, Université Bordeaux Segalen - Bordeaux 2-CHU Bordeaux [Bordeaux], CHU Strasbourg, Service de Néphrologie [Nantes], Centre hospitalier universitaire de Nantes (CHU Nantes), Service de Néphrologie - Immunologie Clinique [Toulouse], Centre Hospitalier Universitaire de Toulouse (CHU Toulouse)-PRES Université de Toulouse, Service de néphrologie [Centre hospitalier de Haguenau], Centre hospitalier de Haguenau, Unité de Soutien Méthodologique à la Recherche Clinique et Epidémiologique, CHU Bordeaux [Bordeaux], Service de Néphrologie-transplantation-dialyse [Bordeaux], Centre de recherche Cardio-Thoracique de Bordeaux [Bordeaux] (CRCTB), Université Bordeaux Segalen - Bordeaux 2-CHU Bordeaux [Bordeaux]-Institut National de la Santé et de la Recherche Médicale (INSERM), Hôpital Haut-Lévêque, Université Sciences et Technologies - Bordeaux 1 (UB)-CHU Bordeaux [Bordeaux], Epidémiologie et Biostatistique [Bordeaux], Université Bordeaux Segalen - Bordeaux 2-Institut de Santé Publique, d'Épidémiologie et de Développement (ISPED)-Institut National de la Santé et de la Recherche Médicale (INSERM), Department of Infectious and Parasitic diseases, Département de cardiologie, CHU Bordeaux [Bordeaux]-Hôpital Haut-Lévêque [CHU Bordeaux], Unité de recherche de l'institut du thorax (ITX-lab), Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Université de Nantes - UFR de Médecine et des Techniques Médicales (UFR MEDECINE), Université de Nantes (UN)-Université de Nantes (UN), CHU Pontchaillou [Rennes], Institut de recherche en santé, environnement et travail (Irset), Université d'Angers (UA)-Université de Rennes (UR)-École des Hautes Études en Santé Publique [EHESP] (EHESP)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Structure Fédérative de Recherche en Biologie et Santé de Rennes ( Biosit : Biologie - Santé - Innovation Technologique ), Service de cardiologie et maladies vasculaires [Rennes] = Cardiac, Thoracic, and Vascular Surgery [Rennes], Centre Hospitalier Universitaire de Toulouse (CHU Toulouse), Department of Nephrology, The First Affiliated Hospital of Sun Yat-sen University, Bordeaux population health (BPH), Université de Bordeaux (UB)-Institut de Santé Publique, d'Épidémiologie et de Développement (ISPED)-Institut National de la Santé et de la Recherche Médicale (INSERM), CHU Toulouse [Toulouse]-Hôpital de Rangueil, CHU Toulouse [Toulouse]-PRES Université de Toulouse, Université Sciences et Technologies - Bordeaux 1-CHU Bordeaux [Bordeaux], unité de recherche de l'institut du thorax UMR1087 UMR6291 (ITX), Université de Nantes - UFR de Médecine et des Techniques Médicales (UFR MEDECINE), Université de Nantes (UN)-Université de Nantes (UN)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS), Université d'Angers (UA)-Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-École des Hautes Études en Santé Publique [EHESP] (EHESP)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Structure Fédérative de Recherche en Biologie et Santé de Rennes ( Biosit : Biologie - Santé - Innovation Technologique ), and CHU Toulouse [Toulouse]

Subjects
medicine.medical_specialty, hemodialysis, implantable loop recorder, business.industry, medicine.medical_treatment, 030232 urology & nephrology, Early detection, sudden death, 030204 cardiovascular system & hematology, Sudden death, 3. Good health, 03 medical and health sciences, 0302 clinical medicine, Cardiac rhythm disturbances, Internal medicine, Implantable loop recorder, medicine, Cardiology, cardiovascular system, In patient, Hemodialysis, cardiovascular diseases, business, Dialysis, [SDV.MHEP]Life Sciences [q-bio]/Human health and pathology
Abstract

International audience; Objectives - The aim of this study was to identify using implantable loop recorder (ILR) monitoring the mechanisms leading to sudden death (SD) in patients undergoing hemodialysis (HD). Background - SD accounts for 11% to 25% of death in HD patients. Methods - Continuous rhythm monitoring was performed using the remote monitoring capability of the ILR device in patients undergoing HD at 8 centers. Clinical, biological, and technical HD parameters were recorded and analyzed. Results - Seventy-one patients (mean age 65 ± 9 years, 73% men) were included. Left ventricular ejection fraction was 5.0 mmol/l, bicarbonate 11.5 g/dl, pre-HD systolic blood pressure >140 mm Hg, the longer interdialytic period, history of coronary artery disease, previous other arrhythmias, and diabetes mellitus. A higher risk for ventricular arrhythmia was associated with potassium

Published
2018
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96. Influences of steps in hybrid rocket engines:Simulation and validation on simplified geometries

Author

C. Glaser, J. Hijlkema, J.-Y. Lestrade, J. Anthoine, ONERA / DMPE, Université de Toulouse [Mauzac], ONERA-PRES Université de Toulouse, ONERA / DMPE, Université de Toulouse [Toulouse], and European Project: 860956,ASCenSIon

Subjects
REGRESSION RATE, [PHYS]Physics [physics], FORWARD FACING STEP, [SPI]Engineering Sciences [physics], LOI D'ARRHENIUS, ARRHENIUS LAW, MARCHE AVANT, Aerospace Engineering, GEOMETRIES SIMPLIFIEES, SIMPLIFIED GEOMETRIES, BACKWARD FACING STEP, TAUX DE REGRESSION, MARCHE ARRIERE
Abstract

International audience; In this study, we investigate the effect of single steps inside the fuel grains of typical hybrid rocket motors numerically. Steps can be a promising candidate to increase the regression rate of hybrid engines. We show that simulations on simplified geometries yield surprisingly close numerical regression rate profiles when compared to experimental data. Moreover, there is no necessity to calculate the progression of the fuel port at different time steps, as a single simulation on the average diameter can match the experiments sufficiently well. This observation allows for larger parametric studies on optimal positioning of the steps while limiting computational resources. The potential to increase the average regression rate through steps can be predicted numerically, and the simulations are following the same trend as the experiments. The augmented mixing and heat transfer inside the turbulent boundary layer can be predicted. It is concluded that backward facing steps increase the regression rate proportional to the step height up to 10 mm, and are preferably utilized upstream. For forward facing steps, the regression rate augmentation is saturated starting with 5 mm step height, and the position should be further downstream.

Published
2023
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97. Residual error based adaptive mesh refinement with the non-intrusive patch algorithm

Author

Michel Salaün, Alexei Lozinski, Jean-Charles Passieux, Mickaël Duval, Calcul en Midi-Pyrénées ( CALMIP ), Institut National Polytechnique [Toulouse] ( INP ) -Institut National des Sciences Appliquées - Toulouse ( INSA Toulouse ), Institut National des Sciences Appliquées ( INSA ) -Institut National des Sciences Appliquées ( INSA ) -Université Paul Sabatier - Toulouse 3 ( UPS ) -PRES Université de Toulouse-Centre National de la Recherche Scientifique ( CNRS ), Laboratoire de Mathématiques de Besançon ( LMB ), Centre National de la Recherche Scientifique ( CNRS ) -Université de Franche-Comté ( UFC ), 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 ) -Institut National des Sciences Appliquées ( INSA ) -Université Paul Sabatier - Toulouse 3 ( UPS ) -Centre National de la Recherche Scientifique ( CNRS ) -IMT École nationale supérieure des Mines d'Albi-Carmaux ( IMT Mines Albi ), Centre National de la Recherche Scientifique - CNRS (FRANCE), Ecole nationale supérieure des Mines d'Albi-Carmaux - IMT Mines Albi (FRANCE), Institut National Polytechnique de Toulouse - Toulouse INP (FRANCE), Institut National des Sciences Appliquées de Toulouse - INSA (FRANCE), Institut Supérieur de l'Aéronautique et de l'Espace - ISAE-SUPAERO (FRANCE), Université Toulouse III - Paul Sabatier - UT3 (FRANCE), Université de Franche-Comté (FRANCE), Calcul en Midi-Pyrénées (CALMIP), Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-PRES Université de Toulouse-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées, Laboratoire de Mathématiques de Besançon (UMR 6623) (LMB), Université de Bourgogne (UB)-Université de Franche-Comté (UFC), Université Bourgogne Franche-Comté [COMUE] (UBFC)-Université Bourgogne Franche-Comté [COMUE] (UBFC)-Centre National de la Recherche Scientifique (CNRS), Institut Clément Ader (ICA), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-IMT École nationale supérieure des Mines d'Albi-Carmaux (IMT Mines Albi), Institut Mines-Télécom [Paris] (IMT)-Institut Mines-Télécom [Paris] (IMT)-Institut Supérieur de l'Aéronautique et de l'Espace (ISAE-SUPAERO), ANR-12-MONU-0002,ICARE,Interfaces Généralisées et Couplage non intrusif : application de codes de recherche au sein de codes industriels pour l'analyse de structures fortement non linéaires(2012), Calcul en Midi-Pyrénée (CALMIP), Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-PRES Université de Toulouse-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT), Centre National de la Recherche Scientifique (CNRS)-Université de Franche-Comté (UFC), Université Bourgogne Franche-Comté [COMUE] (UBFC)-Université Bourgogne Franche-Comté [COMUE] (UBFC), 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), and Institut National Polytechnique de Toulouse - INPT (FRANCE)

Subjects
Multiscale, Mathematical optimization, Computer science, Finite elements, Computational Mechanics, General Physics and Astronomy, [ SPI.MECA.STRU ] Engineering Sciences [physics]/Mechanics [physics.med-ph]/Mechanics of the structures [physics.class-ph], 010103 numerical & computational mathematics, Finite Elements, Mesh refinement, Residual, 01 natural sciences, Mathématiques générales, Error estimation, Convergence (routing), Non-intrusive coupling, 0101 mathematics, Adaptive mesh refinement, Mechanical Engineering, Process (computing), Estimator, Finite element method, Computer Science Applications, 010101 applied mathematics, Mechanics of Materials, [SPI.MECA.STRU]Engineering Sciences [physics]/Mechanics [physics.med-ph]/Structural mechanics [physics.class-ph], Algorithm
Abstract

International audience; This paper deals with the introduction of mesh refinement techniques within the non-intrusive patch process. For this, an ad hoc residual based explicit error estimator is built, which is adapted to a multi-scale solution, associated with those non-intrusive mesh refinement technique. Moreover, to reduce the global cost of the process, one introduces an estimate of the convergence error of the non-intrusive algorithm, which allows to reduce the number of iterations. This method is discussed and illustrated on various numerical examples.

Published
2018
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98. SEFI Modeling in Readout Integrated Circuit induced by Heavy Ions at Cryogenic Temperatures

Author

Julien Mekki, Guillaume Hubert, F. Advent, S. Ducret, Laurent Artola, André, Cécile, ONERA / DPHY, Université de Toulouse [Toulouse], ONERA-PRES Université de Toulouse, SOFRADIR (Veurey-Voroize), Centre National d'Études Spatiales [Toulouse] (CNES), and PRES Université de Toulouse-ONERA

Subjects
Nuclear and High Energy Physics, SINGLE EVENT FUNCTIONAL INTERRUPT, Semiconductor device modeling, 02 engineering and technology, Radiation, 01 natural sciences, Ion, law.invention, LOW TEMPERATURES, Readout integrated circuit, MODELING, HEAVY IONS, Robustness (computer science), law, [PHYS.PHYS.PHYS-PLASM-PH]Physics [physics]/Physics [physics]/Plasma Physics [physics.plasm-ph], DETECTEURS INFRAROUGES, 0103 physical sciences, 0202 electrical engineering, electronic engineering, information engineering, Electrical and Electronic Engineering, [PHYS.PHYS.PHYS-ATOM-PH] Physics [physics]/Physics [physics]/Atomic Physics [physics.atom-ph], [PHYS.PHYS.PHYS-SPACE-PH] Physics [physics]/Physics [physics]/Space Physics [physics.space-ph], Physics, [PHYS.PHYS.PHYS-ATOM-PH]Physics [physics]/Physics [physics]/Atomic Physics [physics.atom-ph], 010308 nuclear & particles physics, business.industry, BASSES TEMPERATURES, Transistor, CIRCUIT INTEGRE, MODELISATION, [PHYS.PHYS.PHYS-SPACE-PH]Physics [physics]/Physics [physics]/Space Physics [physics.space-ph], 020202 computer hardware & architecture, INFRARED DETECTORS, IONS LOURDS, READOUT INTEGRATED CIRCUIT, Nuclear Energy and Engineering, [PHYS.PHYS.PHYS-PLASM-PH] Physics [physics]/Physics [physics]/Plasma Physics [physics.plasm-ph], Optoelectronics, Infrared image sensors, Interrupt, business
Abstract

This paper presents a modeling approach of single-event functional interrupt (SEFI) which takes into account all the physical and electrical processes from the radiation particle down to the event at the system level. This paper is focused on the evaluation of SEFI sensitivity by experimental and simulation analyses of a readout integrated circuit (ROIC) designed by Sofradir for their infrared image sensors. Relevant correlations between simulation and experimental results of SEFI cross sections for heavy ions are presented and discussed. The simulation results confirm the strong SEFI robustness of the ROIC at 57 K.

Published
2018

99. Damage Factor for Radiation-Induced Dark Current in InGaAs Photodiodes

Author

Christophe Inguimbert, Juan Moreno, Audrey Delbergue, T. Nuns, Lip Sun How, Mathieu Boutillier, Stephane Mariojouls, Olivier Gilard, Louis Bouet, Juan Barbero, Centre National d'Études Spatiales [Toulouse] (CNES), AdvEOTec, ONERA / DPHY, Université de Toulouse [Toulouse], ONERA-PRES Université de Toulouse, ALTER Technology, Airbus Defence and Space [Toulouse], Centre National d’Études Spatiales [Paris] (CNES), and PRES Université de Toulouse-ONERA

Subjects
Nuclear and High Energy Physics, Materials science, Physics::Instrumentation and Detectors, Physics::Medical Physics, Electron, Radiation, DOMMAGE DE DEPLACEMENT, 01 natural sciences, COURANT D'OBSCURITE, law.invention, Ion, [SPI.MAT]Engineering Sciences [physics]/Materials, chemistry.chemical_compound, law, 0103 physical sciences, Irradiation, Electrical and Electronic Engineering, 010308 nuclear & particles physics, business.industry, INDIUM GALLIUM ARSENIDE (InGaAs) DEVICES, PHOTODIODES, Alpha particle, Condensed Matter::Mesoscopic Systems and Quantum Hall Effect, [PHYS.PHYS.PHYS-SPACE-PH]Physics [physics]/Physics [physics]/Space Physics [physics.space-ph], Photodiode, INGAAS, DISPLACEMENT DAMAGE, Nuclear Energy and Engineering, chemistry, Optoelectronics, DARK CURRENT, business, Indium gallium arsenide, Dark current
Abstract

International audience; In this paper, a compendium of InGaAs photodiode irradiation test results is presented. These photodiodes were irradiated either with γ-rays, protons, neutrons, electrons, pions, alpha particles, or carbon ions of various energies. The displacement damage dose formalism was found to be effective in describing the radiation-induced dark current increase of any of the studied InGaAs photodiodes. The exploitation of capacitancebias voltage and current-bias voltage measurements also allows us to deduce a damage factor that can be used to assess the radiation-induced dark current in a great number of radiation environments.

Published
2018
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100. Q-processes and asymptotic properties of Markov processes conditioned not to hit moving boundaries

Author

Oçafrain , William, Institut de Mathématiques de Toulouse UMR5219 (IMT), Université Toulouse 1 Capitole (UT1)-Université Toulouse - Jean Jaurès (UT2J)-Université Toulouse III - Paul Sabatier (UPS), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-PRES Université de Toulouse-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-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), Centre National de la Recherche Scientifique (CNRS)-PRES Université de Toulouse-Université Toulouse III - Paul Sabatier (UPS), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Université Toulouse - Jean Jaurès (UT2J)-Université Toulouse 1 Capitole (UT1), 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 des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Université Toulouse 1 Capitole (UT1)-Université Toulouse - Jean Jaurès (UT2J)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS), Institut de Mathématiques de Toulouse UMR5219 ( IMT ), Université Toulouse 1 Capitole ( UT1 ) -Université Toulouse - Jean Jaurès ( UT2J ) -Université Toulouse III - Paul Sabatier ( UPS ), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-PRES Université de Toulouse-Institut National des Sciences Appliquées - Toulouse ( INSA Toulouse ), and Institut National des Sciences Appliquées ( INSA ) -Institut National des Sciences Appliquées ( INSA ) -Centre National de la Recherche Scientifique ( CNRS )

Subjects
quasi-limit distribution, 60J50 Secondary : 60J60, quasi-limiting distribution, quasi-ergodic distri- bution, Probability (math.PR), quasi-ergodic distribution, mov- ing boundaries, one- dimensional diffusion processes, one-dimensional diffusion processes, time-inhomogeneous Markov processes, [MATH.MATH-PR]Mathematics [math]/Probability [math.PR], 60J05, 60J25, Q-process, FOS: Mathematics, moving boundaries, one-dimensional diffusion processes 2010 Mathematics Subject Classification Primary : 60B10, [ MATH.MATH-PR ] Mathematics [math]/Probability [math.PR], 60F99, Mathematics - Probability
Abstract

We investigate some asymptotic properties of general Markov processes conditioned not to be absorbed by moving boundaries. We first give general criteria involving an exponential convergence towards the Q-process, that is the law of the considered Markov process conditioned never to reach the moving boundaries. This exponential convergence allows us to state the existence and uniqueness of quasi-ergodic distribution considering either boundaries moving periodically or stabilizing boundaries. We also state the existence and uniqueness of quasi-limit distribution when absorbing boundaries stabilize. We finally deal with some examples such as diffusions which are coming down from infinity., Comment: Stochastic Processes and their Applications, Elsevier, In press

Published
2018
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