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1. Establishing a national research software award [version 1; peer review: 2 approved]

Author

Roberto Di Cosmo, Isabelle Blanc Catala, Daniel Le Berre, Mathieu Giraud, Sophie Renaudin, and Violaine Louvet

Subjects
open science, research software, open-source software, software engineering, research policy, institutional support, eng, Science, Social Sciences
Abstract

Software development has become an integral part of the scholarly ecosystem, spanning all fields and disciplines. To support the sharing and creation of knowledge in line with open science principles, and particularly to enable the reproducibility of research results, it is crucial to make the source code of research software available, allowing for modification, reuse, and distribution. Recognizing the significance of open-source software contributions in academia, the second French Plan for Open Science, announced by the Minister of Higher Education and Research in 2021, introduced a National Award to promote open-source research software. This award serves multiple objectives: firstly, to highlight the software projects and teams that have devoted time and effort to develop outstanding research software, sometimes for decades, and often with little recognition; secondly, to draw attention to the importance of software as a valuable research output and to inspire new generations of researchers to follow and learn from these examples. We present here an in-depth analysis of the design and implementation of this unique initiative. As a national award established explicitly to foster Open Science practices by the French Minister of Research, it faced the intricate challenge of fairly evaluating open research software across all fields, striving for inclusivity across domains, applications, and participants. We provide a comprehensive report on the results of the first edition, which received 129 high-quality submissions. Additionally, we emphasize the impact of this initiative on the open science landscape, promoting software as a valuable research outcome, on par with publications.

Published
2023
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2. New Resolution Strategies for Multi-scale Reaction Waves: Optimal Time Operator Splitting and Space Adaptive Multiresolution

Author

Max Duarte, Marc Massot, Frédérique Laurent, Stéphane Descombes, Christian Tenaud, Thierry Dumont, and Violaine Louvet

Subjects
Electronic computers. Computer science, QA75.5-76.95
Abstract

We tackle the numerical simulation of reaction-diffusion equations modeling multi-scale reac- tion waves. This type of problems induces peculiar difficulties and potentially large stiffness which stem from the broad spectrum of temporal scales in the nonlinear chemical source term as well as from the presence of large spatial gradients in the reaction fronts, spatially very lo- calized. In this paper, we introduce a new resolution strategy based on time operator splitting and space adaptive multiresolution in the context of very localized and stiff reaction fronts. Based on recent theoretical studies of numerical analysis, such a strategy leads to a splitting time step which is not restricted neither by the fastest scales in the source term nor by restric- tive diffusive step stability limits, but only by the physics of the phenomenon. We thus aim at solving accurately complete models including all time and space scales of the phenomenon, considering large simulation domains with conventional computing resources. The efficiency is evaluated through the numerical simulation of configurations which were so far out of reach of standard methods in the field of nonlinear chemical dynamics for 2D spiral waves and 3D scroll waves as an illustration. Future extensions of the proposed strategy are finally discussed.

Published
2011
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3. Les Troubles et le conflit au Moyen-Orient : alliances coloniales et solidarité transnationale

Author

Marie-Violaine Louvet

Subjects
unionism, republicanism, nationalism, loyalism, Palestine, Israel, History of Great Britain, DA1-995, English literature, PR1-9680
Abstract

During the Troubles in Northern Ireland, particularly between the end of the 1970s and the beginning of the 1980s, the urban landscape of certain Catholic districts took on the colours of the Palestinian flag. Whether painted on murals, hung on buildings or waved at demonstrations, the flags reflected an identification with the Palestinian cause that, like the Northern Ireland conflict, was read through the prism of the colonial question and partition. In addition, the experiences of incarceration, administrative detention and hunger strike provided fertile ground for transnational solidarity links to flourish between certain armed groups such as the Irish Republican Army or the Irish National Liberation Army and the Palestine Liberation Organisation. These links of solidarity between certain Northern Irish republican factions and certain Palestinian organisations took the form of exchanges of weapons, ammunition and knowledge of explosives. Much later, in the early 2000s, after the signing of the Good Friday Agreement and the start of the second Intifada, Palestinian flags once again made a very visible appearance at republican demonstrations, such as the annual Bloody Sunday commemorations. Israeli flags also appeared in some Protestant neighbourhoods in Northern Ireland, notably on the initiative of the Ulster Defence Association, highlighting a discourse based on the obsidional mentality of the Unionist community, and often nourished by religious beliefs. While peace was signed in Northern Ireland, and the violence gradually subsided, the conflict shifted to the symbolic level, suggesting that the reconciliation process was not entirely successful. Through a study of primary sources (interviews, activist press, grey literature, general press) this essay sheds light on the origins of the republican identification with the Palestinian cause, its implications and its use by the Sinn Féin republican party for pragmatic purposes. It also looks at unionist demonstrations in support of Israel, trying to identify political and religious affinities. This support for the belligerents in the Middle East conflict allows us to question the unfinished nature of the peace process in Northern Ireland, and the divisions that persist « in hearts and minds », in the words of John Hume.

Published
2024

4. Obligations postcoloniales et Guerre du Vietnam en République d’Irlande (1965-1975)

Author

Marie-Violaine Louvet

Subjects
guerre du Vietnam, identité postcoloniale, activisme anti-guerre, Irlande, History (General), D1-2009, Social Sciences
Abstract

L’histoire coloniale de la république d’Irlande, sous le joug de son puissant voisin britannique entre le xiie et le début du xxe, a une influence indéniable sur sa place au sein des nations et sur son positionnement par rapport aux pays du tiers-monde. En tant que seul pays européen avec une identité postcoloniale, des liens de solidarité particuliers se tissent avec certains peuples en proie à ce qui est identifié comme des conflits néocoloniaux par certains activistes, principalement républicains et de gauche, mais pas uniquement. C’est le cas pendant la guerre du Vietnam, en particulier à partir des bombardements américains sur le Nord-Vietnam au milieu des années 1960, avec la création de l’association Irish Voice on Vietnam (IVOV). Cet article s’attache à expliquer l’action d’une section de la société civile en Irlande contre la guerre du Vietnam et à en démontrer l’originalité, par rapport aux mouvements présents dans d’autres pays qui ne partagent pas la même identité postcoloniale.

Published
2023
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5. Interculturalism in Sam Najjair’s account of the battle for Tripoli: Soldier for a Summer

Author

Marie-Violaine Louvet

Subjects
Ireland, Libya, Interculturalism, Autobiography, Tripoli Brigade, Sam Najjair., History of Great Britain, DA1-995, Language and Literature
Abstract

Interculturalism is the result of an interaction between different cultures and the possibility of the emergence of a new form of cultural expression and identity. This article studies the process of conciliation or re-conciliation of two cultures in Sam Najjair’s book Soldier for a Summer. This is the diary of an Irish Libyan citizen who participated in the liberation of Tripoli from Gaddafi’s rule in the Summer of 2011, during the Libyan civil war. The reader follows the main character from Dublin to Tripoli and then back to Dublin at the end of the war. In the book, which is first and foremost targeted at the Irish public to try to gather support for the revolution, Sam Najjair outlines an intercultural space between Ireland and Libya, opening ‘an Irish angle’ on the Libyan conflict, directly connected to his dual identity of a Libyan second generation immigrant living in Ireland.

Published
2016

7. The Irish Against the War : Postcolonial Identity & Political Activism in Contemporary Ireland

Author

Marie-Violaine Louvet and Marie-Violaine Louvet

Subjects
Ireland-Politics and government-1949-
Abstract

The purpose of the book is to explore and explicate the origins, evolution and mobilisation of anti-war activism in Ireland from the 1950s. The author applies postcolonial critical perspectives alongside social movement theory to define the multifaceted Irish approach to different international conflicts from the creation of the Irish Campaign for Nuclear Disarmament (1958) to the current war in Ukraine. Meticulously researched, the chapters develop an analysis of the anti-war activism in Ireland, be it at a local, national or supranational level, from political parties, trade unions and civil associations. The book casts light on the factors that structure the Irish domestication of the conflicts under study, be they historical and connected to senses of national identity in the Irish Republic and Northern Ireland, or strategic, diplomatic and religious.

Published
2024

8. Population parametrization of costly black box models using iterations between SAEM algorithm and kriging

Author

Emmanuel Grenier, Paul Vigneaux, Céline Helbert, Adeline Samson, Violaine Louvet, Unité de Mathématiques Pures et Appliquées (UMPA-ENSL), École normale supérieure de Lyon (ENS de Lyon)-Centre National de la Recherche Scientifique (CNRS), Numerical Medicine (NUMED), École normale supérieure de Lyon (ENS de Lyon)-Centre National de la Recherche Scientifique (CNRS)-École normale supérieure de Lyon (ENS de Lyon)-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), Institut Camille Jordan (ICJ), École Centrale de Lyon (ECL), Université de Lyon-Université de Lyon-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Institut National des Sciences Appliquées de Lyon (INSA Lyon), Université de Lyon-Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Université Jean Monnet - Saint-Étienne (UJM)-Centre National de la Recherche Scientifique (CNRS), Probabilités, statistique, physique mathématique (PSPM), Université de Lyon-Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Université Jean Monnet - Saint-Étienne (UJM)-Centre National de la Recherche Scientifique (CNRS)-École Centrale de Lyon (ECL), Modélisation mathématique, calcul scientifique (MMCS), Statistique pour le Vivant et l’Homme (SVH), 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])-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]), PEPS Egalité Integer Project, Fédération de Recherche en Mathématiques Rhône-Alpes-Auvergne (FR 3490 CNRS), CNRS FR 3490, Project D04, 2015, ANR-11-LABX-0025,PERSYVAL-lab,Systemes et Algorithmes Pervasifs au confluent des mondes physique et numérique(2011), Centre National de la Recherche Scientifique (CNRS)-École normale supérieure - Lyon (ENS Lyon), Centre National de la Recherche Scientifique (CNRS)-École normale supérieure - Lyon (ENS Lyon)-Centre National de la Recherche Scientifique (CNRS)-École normale supérieure - Lyon (ENS Lyon)-Inria Grenoble - Rhône-Alpes, Institut Camille Jordan [Villeurbanne] (ICJ), Université de Lyon-Université Jean Monnet [Saint-Étienne] (UJM)-Institut National des Sciences Appliquées de Lyon (INSA Lyon), Université de Lyon-Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS), and Université de Lyon-Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS)-École Centrale de Lyon (ECL)

Subjects
0209 industrial biotechnology, Mathematical optimization, Population, SAEM algorithm, KPP equation, 02 engineering and technology, 01 natural sciences, Non-linear Mixed Effect Models, 010104 statistics & probability, 020901 industrial engineering & automation, Kriging, Black box, MSC: 65C60 65C40 62M05 60G15 65M32 65N21 35K57, Parameters estimation, 0101 mathematics, education, Mathematics, education.field_of_study, Partial differential equation, Basis (linear algebra), Applied Mathematics, Partial Differential Equations, Metamodeling, Computational Mathematics, Focus (optics), Algorithm, Parametrization, [MATH.MATH-NA]Mathematics [math]/Numerical Analysis [math.NA]
Abstract

Accepted March, 24, 2016. Published online April, 16, 2016. Journal issue available Feb 23, 2018.; International audience; In this article we focus on parametrization of black box models from repeated measurements among several individuals (population parametrization). We introduce a variant of the SAEM algorithm, called KSAEM algorithm, which couples the standard SAEM algorithm with the dynamic construction of an approximate meta model. The costly evaluation of the genuine black box is replaced by a kriging step, using a basis of precomputed values, basis which is enlarged during SAEM algorithm to improve the accuracy of the meta model in regions of interest.

Published
2018
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9. Simulation of human ischemic stroke in realistic 3D geometry

Author

Violaine Louvet, Stéphane Descombes, Max Duarte, Marie-Aimée Dronne, Thierry Dumont, Marc Massot, Institut Camille Jordan [Villeurbanne] (ICJ), École Centrale de Lyon (ECL), Université de Lyon-Université de Lyon-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université Jean Monnet [Saint-Étienne] (UJM)-Institut National des Sciences Appliquées de Lyon (INSA Lyon), Université de Lyon-Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS), Laboratoire d'Énergétique Moléculaire et Macroscopique, Combustion (EM2C), Université Paris Saclay (COmUE)-Centre National de la Recherche Scientifique (CNRS)-CentraleSupélec, Laboratoire Jean Alexandre Dieudonné (JAD), Université Nice Sophia Antipolis (... - 2019) (UNS), COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Centre National de la Recherche Scientifique (CNRS), Numerical modeling and high performance computing for evolution problems in complex domains and heterogeneous media (NACHOS), 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)-Laboratoire Jean Alexandre Dieudonné (JAD), Université Côte d'Azur (UCA)-Université Nice Sophia Antipolis (... - 2019) (UNS), COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Centre National de la Recherche Scientifique (CNRS)-Université Côte d'Azur (UCA)-Université Nice Sophia Antipolis (... - 2019) (UNS), Evaluation et modélisation des effets thérapeutiques, Département biostatistiques et modélisation pour la santé et l'environnement [LBBE], Laboratoire de Biométrie et Biologie Evolutive - UMR 5558 (LBBE), Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut National de Recherche en Informatique et en Automatique (Inria)-VetAgro Sup - Institut national d'enseignement supérieur et de recherche en alimentation, santé animale, sciences agronomiques et de l'environnement (VAS)-Centre National de la Recherche Scientifique (CNRS)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut National de Recherche en Informatique et en Automatique (Inria)-VetAgro Sup - Institut national d'enseignement supérieur et de recherche en alimentation, santé animale, sciences agronomiques et de l'environnement (VAS)-Centre National de la Recherche Scientifique (CNRS)-Laboratoire de Biométrie et Biologie Evolutive - UMR 5558 (LBBE), Université de Lyon-Université de Lyon-Institut National de Recherche en Informatique et en Automatique (Inria)-VetAgro Sup - Institut national d'enseignement supérieur et de recherche en alimentation, santé animale, sciences agronomiques et de l'environnement (VAS)-Centre National de la Recherche Scientifique (CNRS), Numerical Medicine (NUMED), Unité de Mathématiques Pures et Appliquées (UMPA-ENSL), Centre National de la Recherche Scientifique (CNRS)-École normale supérieure - Lyon (ENS Lyon)-Centre National de la Recherche Scientifique (CNRS)-École normale supérieure - Lyon (ENS Lyon)-Inria Grenoble - Rhône-Alpes, Institut National de Recherche en Informatique et en Automatique (Inria)-Institut National de Recherche en Informatique et en Automatique (Inria), Project NUMED, INRIA ENS Lyon - Project NACHOS, INRIA, Institut Camille Jordan (ICJ), Université de Lyon-Institut National des Sciences Appliquées de Lyon (INSA Lyon), Université de Lyon-Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Université Jean Monnet - Saint-Étienne (UJM)-Centre National de la Recherche Scientifique (CNRS), CentraleSupélec-Centre National de la Recherche Scientifique (CNRS)-Université Paris Saclay (COmUE), Université Nice Sophia Antipolis (1965 - 2019) (UNS), Institut National de Recherche en Informatique et en Automatique (Inria)-Institut National de Recherche en Informatique et en Automatique (Inria)-Laboratoire Jean Alexandre Dieudonné (LJAD), COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Centre National de la Recherche Scientifique (CNRS)-Université Côte d'Azur (UCA)-Université Nice Sophia Antipolis (1965 - 2019) (UNS), COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Centre National de la Recherche Scientifique (CNRS)-Université Côte d'Azur (UCA), and École normale supérieure de Lyon (ENS de Lyon)-Centre National de la Recherche Scientifique (CNRS)-École normale supérieure de Lyon (ENS de Lyon)-Centre National de la Recherche Scientifique (CNRS)-Inria Grenoble - Rhône-Alpes

Subjects
Theoretical computer science, Computer science, 010103 numerical & computational mathematics, 01 natural sciences, 03 medical and health sciences, 0302 clinical medicine, Complex geometry, Reaction–diffusion system, [MATH.MATH-AP]Mathematics [math]/Analysis of PDEs [math.AP], 0101 mathematics, 35A35, 35K57, 65L06, 65M08, 65M50, 65Y05, 92B05, Numerical Analysis, Ischemic stroke, Mathematical model, Computer simulation, parallel computing, Applied Mathematics, Numerical analysis, [INFO.INFO-MO]Computer Science [cs]/Modeling and Simulation, Term (time), Nonlinear system, reaction-diffusion equations, Shared memory, Modeling and Simulation, [INFO.INFO-DC]Computer Science [cs]/Distributed, Parallel, and Cluster Computing [cs.DC], Algorithm, 030217 neurology & neurosurgery, operator splitting
Abstract

The authors would like to thank Christian Tenaud (LIMSI - CNRS) for providing the basis of the multi-resolution kernel of MR CHORUS, code that he developed at LIMSI for compressible Navier-Stokes equations.; International audience; In silico research in medicine is thought to reduce the need for expensive clinical trials under the condition of reliable mathematical models and accurate and efficient numerical methods. In the present work, we tackle the numerical simulation of reaction-diffusion equations modeling human ischemic stroke. This problem induces peculiar difficulties like potentially large stiffness which stems from the broad spectrum of temporal scales in the nonlinear chemical source term as well as from the presence of steep spatial gradients in the reaction fronts, spatially very localized. Furthermore, simulations on realistic 3D geometries are mandatory in order to describe correctly this type of phenomenon. The main goal of this article is to obtain, for the first time, 3D simulations on realistic geometries and to show that the simulation results are consistent with those obtain in experimental studies or observed on MRI images in stroke patients. For this purpose, we introduce a new resolution strategy based mainly on time operator splitting that takes into account complex geometry coupled with a well-conceived parallelization strategy for shared memory architectures. We consider then a high order implicit time integration for the reaction and an explicit one for the diffusion term in order to build a time operator splitting scheme that exploits efficiently the special features of each problem. Thus, we aim at solving complete and realistic models including all time and space scales with conventional computing resources, that is on a reasonably powerful workstation. Consequently and as expected, 2D and also fully 3D numerical simulations of ischemic strokes for a realistic brain geometry, are conducted for the first time and shown to reproduce the dynamics observed on MRI images in stroke patients. Beyond this major step, in order to improve accuracy and computational efficiency of the simulations, we indicate how the present numerical strategy can be coupled with spatial adaptive multiresolution schemes. Preliminary results in the framework of simple geometries allow to assess the proposed strategy for further developments.

Published
2013
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10. Statistical Inference for Partial Differential Equations

Author

Tony Lelièvre, Marc Hoffmann, Paul Vigneaux, Clémentine Prieur, Violaine Louvet, Emmanuel Grenier, Nabil Rachdi, Numerical Medicine (NUMED), Unité de Mathématiques Pures et Appliquées (UMPA-ENSL), Centre National de la Recherche Scientifique (CNRS)-École normale supérieure - Lyon (ENS Lyon)-Centre National de la Recherche Scientifique (CNRS)-École normale supérieure - Lyon (ENS Lyon)-Inria Grenoble - Rhône-Alpes, Institut National de Recherche en Informatique et en Automatique (Inria)-Institut National de Recherche en Informatique et en Automatique (Inria), Centre National de la Recherche Scientifique (CNRS)-École normale supérieure - Lyon (ENS Lyon), CEntre de REcherches en MAthématiques de la DEcision (CEREMADE), Centre National de la Recherche Scientifique (CNRS)-Université Paris Dauphine-PSL, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL), Centre d'Enseignement et de Recherche en Mathématiques, Informatique et Calcul Scientifique (CERMICS), Institut National de Recherche en Informatique et en Automatique (Inria)-École des Ponts ParisTech (ENPC), Institut Camille Jordan [Villeurbanne] (ICJ), École Centrale de Lyon (ECL), Université de Lyon-Université de Lyon-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université Jean Monnet [Saint-Étienne] (UJM)-Institut National des Sciences Appliquées de Lyon (INSA Lyon), Institut National des Sciences Appliquées (INSA)-Université de Lyon-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS), Modélisation mathématique, calcul scientifique (MMCS), Institut National des Sciences Appliquées (INSA)-Université de Lyon-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS)-École Centrale de Lyon (ECL), Modelling, Observations, Identification for Environmental Sciences (MOISE), 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), Centre National de la Recherche Scientifique (CNRS)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Université Joseph Fourier - Grenoble 1 (UJF)-Université Pierre Mendès France - Grenoble 2 (UPMF)-Centre National de la Recherche Scientifique (CNRS)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Université Joseph Fourier - Grenoble 1 (UJF)-Université Pierre Mendès France - Grenoble 2 (UPMF), ASTRIUM, EADS - European Aeronautic Defense and Space, École normale supérieure de Lyon (ENS de Lyon)-Centre National de la Recherche Scientifique (CNRS)-École normale supérieure de Lyon (ENS de Lyon)-Centre National de la Recherche Scientifique (CNRS)-Inria Grenoble - Rhône-Alpes, École normale supérieure de Lyon (ENS de Lyon)-Centre National de la Recherche Scientifique (CNRS), Université Paris Dauphine-PSL, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS), Institut Camille Jordan (ICJ), Université de Lyon-Institut National des Sciences Appliquées de Lyon (INSA Lyon), Université de Lyon-Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Université Jean Monnet - Saint-Étienne (UJM)-Centre National de la Recherche Scientifique (CNRS), Université de Lyon-Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Université Jean Monnet - Saint-Étienne (UJM)-Centre National de la Recherche Scientifique (CNRS)-École Centrale de Lyon (ECL), and Université Pierre Mendès France - Grenoble 2 (UPMF)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS)-Université Pierre Mendès France - Grenoble 2 (UPMF)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS)

Subjects
T57-57.97, Mathematical optimization, Applied mathematics. Quantitative methods, Partial differential equation, Computer science, 010103 numerical & computational mathematics, computer.software_genre, 01 natural sciences, Reduction (complexity), 010104 statistics & probability, [MATH.MATH-ST]Mathematics [math]/Statistics [math.ST], Physical phenomena, QA1-939, Statistical inference, Data mining, 0101 mathematics, Greedy algorithm, Real world data, computer, Mathematics, Interpolation, Parametric statistics
Abstract

Many physical phenomena are modeled by parametrized PDEs. The poor knowledge on the involved parameters is often one of the numerous sources of uncertainties on these models. Some of these parameters can be estimated, with the use of real world data. The aim of this mini-symposium is to introduce some of the various tools from both statistical and numerical communities to deal with this issue. Parametric and non-parametric approaches are developed in this paper. Some of the estimation procedures require many evaluations of the initial model. Some interpolation tools and some greedy algorithms for model reduction are therefore also presented, in order to reduce time needed for running the model.

Published
2013
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11. New resolution strategy for multi-scale reaction waves using time operator splitting, space adaptive multiresolution and dedicated high order implicit/explicit time integrators

Author

Christian Tenaud, Thierry Dumont, Frédérique Laurent, Max Duarte, Stéphane Descombes, Violaine Louvet, Marc Massot, Laboratoire d'Énergétique Moléculaire et Macroscopique, Combustion (EM2C), CentraleSupélec-Centre National de la Recherche Scientifique (CNRS)-Université Paris Saclay (COmUE), Laboratoire Jean Alexandre Dieudonné (JAD), Université Nice Sophia Antipolis (1965 - 2019) (UNS), COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Centre National de la Recherche Scientifique (CNRS), Laboratoire d'Informatique pour la Mécanique et les Sciences de l'Ingénieur (LIMSI), Université Paris-Sud - Paris 11 (UP11)-Sorbonne Université - UFR d'Ingénierie (UFR 919), Sorbonne Université (SU)-Sorbonne Université (SU)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Université Paris Saclay (COmUE), Institut Camille Jordan (ICJ), École Centrale de Lyon (ECL), Université de Lyon-Université de Lyon-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Institut National des Sciences Appliquées de Lyon (INSA Lyon), Université de Lyon-Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Université Jean Monnet - Saint-Étienne (UJM)-Centre National de la Recherche Scientifique (CNRS), Numerical Medicine (NUMED), Unité de Mathématiques Pures et Appliquées (UMPA-ENSL), École normale supérieure de Lyon (ENS de Lyon)-Centre National de la Recherche Scientifique (CNRS)-École normale supérieure de Lyon (ENS de Lyon)-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), This research was supported by a fundamental projects grant from ANR (French National Research Agency - ANR Blancs) 'Séchelles', Project leader S. Descombes, by a CNRS Ph.D. grant for M. Duarte from the Institute of Mathematics (INSMI) and Engineering Institute (INSIS) of CNRS, and through a PEPS Maths-ST2I CNRS project (V. Louvet)., ANR-09-BLAN-0075,Séchelles,Simulation et comparaison avec l'expérience pour la validation de modèles de problèmes multi-échelles.(2009), Université Paris Saclay (COmUE)-Centre National de la Recherche Scientifique (CNRS)-CentraleSupélec, Université Nice Sophia Antipolis (... - 2019) (UNS), Université Paris Saclay (COmUE)-Centre National de la Recherche Scientifique (CNRS)-Sorbonne Université - UFR d'Ingénierie (UFR 919), Sorbonne Université (SU)-Sorbonne Université (SU)-Université Paris-Saclay-Université Paris-Sud - Paris 11 (UP11), Institut Camille Jordan [Villeurbanne] (ICJ), Université de Lyon-Université Jean Monnet [Saint-Étienne] (UJM)-Institut National des Sciences Appliquées de Lyon (INSA Lyon), Institut National des Sciences Appliquées (INSA)-Université de Lyon-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS), and Centre National de la Recherche Scientifique (CNRS)-École normale supérieure - Lyon (ENS Lyon)-Centre National de la Recherche Scientifique (CNRS)-École normale supérieure - Lyon (ENS Lyon)-Inria Grenoble - Rhône-Alpes

Subjects
Spacetime, Computer simulation, Applied Mathematics, Numerical analysis, [SPI.FLUID]Engineering Sciences [physics]/Reactive fluid environment, Mathematical analysis, Context (language use), 010103 numerical & computational mathematics, 01 natural sciences, Term (time), 010101 applied mathematics, Adaptive multiresolution, Computational Mathematics, Nonlinear system, Multi-scale waves, Integrator, Reaction–diffusion system, Applied mathematics, [MATH.MATH-AP]Mathematics [math]/Analysis of PDEs [math.AP], Operator splitting, 0101 mathematics, Reaction-diffusion, MCS : 65M50, 35K57, 65M08, [MATH.MATH-NA]Mathematics [math]/Numerical Analysis [math.NA], Mathematics
Abstract

We tackle the numerical simulation of reaction-diffusion equations modeling multi-scale reaction waves. This type of problem induces peculiar difficulties and potentially large stiffness which stem from the broad spectrum of temporal scales in the nonlinear chemical source term as well as from the presence of steep spatial gradients in the reaction fronts, spatially very localized. In this paper, we introduce a new resolution strategy based on time operator splitting and space adaptive multiresolution in the context of very localized and stiff reaction fronts. The paper considers a high order implicit time integration of the reaction and an explicit one for the diffusion term in order to build a time operator splitting scheme that exploits efficiently the special features of each problem. Based on recent theoretical studies of numerical analysis such a strategy leads to a splitting time step which is restricted by neither the fastest scales in the source term nor by stability constraints of the diffusive steps but only by the physics of the phenomenon. We aim thus at solving complete models including all time and space scales within a prescribed accuracy, considering large simulation domains with conventional computing resources. The efficiency is evaluated through the numerical simulation of configurations which were so far out of reach of standard methods in the field of nonlinear chemical dynamics for two-dimensional spiral waves and three-dimensional scroll waves, as an illustration. Future extensions of the proposed strategy to more complex configurations involving other physical phenomena as well as optimization capability on new computer architectures are discussed.

Published
2012
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12. On the local and global errors of splitting approximations of reaction-diffusion equations with high spatial gradients

Author

Stéphane Descombes, Marc Massot, Violaine Louvet, Thierry Dumont, Unité de Mathématiques Pures et Appliquées (UMPA-ENSL), École normale supérieure de Lyon (ENS de Lyon)-Centre National de la Recherche Scientifique (CNRS), Laboratoire d'Énergétique Moléculaire et Macroscopique, Combustion (EM2C), CentraleSupélec-Centre National de la Recherche Scientifique (CNRS)-Université Paris Saclay (COmUE), Institut Camille Jordan (ICJ), École Centrale de Lyon (ECL), Université de Lyon-Université de Lyon-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Institut National des Sciences Appliquées de Lyon (INSA Lyon), Université de Lyon-Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Université Jean Monnet - Saint-Étienne (UJM)-Centre National de la Recherche Scientifique (CNRS), ACI Nouvelles Interfaces des Mathématiques 2003-2006 (S. Descombes, M. Massot), École normale supérieure - Lyon (ENS Lyon)-Centre National de la Recherche Scientifique (CNRS), Université Paris Saclay (COmUE)-Centre National de la Recherche Scientifique (CNRS)-CentraleSupélec, Institut Camille Jordan [Villeurbanne] (ICJ), Université de Lyon-Université Jean Monnet [Saint-Étienne] (UJM)-Institut National des Sciences Appliquées de Lyon (INSA Lyon), and Université de Lyon-Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Partial differential equation, Discretization, Differential equation, Applied Mathematics, 010102 general mathematics, Mathematical analysis, First-order partial differential equation, Commutator (electric), 010103 numerical & computational mathematics, Function (mathematics), 01 natural sciences, Computer Science Applications, law.invention, Splitting approximation errors, High spatial gradients, Computational Theory and Mathematics, Reaction-diffusion equations, law, Ordinary differential equation, Reaction–diffusion system, 0101 mathematics, MSC 65M15, MSC 65M05, MSC 65N15, [MATH.MATH-NA]Mathematics [math]/Numerical Analysis [math.NA], Mathematics
Abstract

Special Issue on Splitting Methods for Differential Equations; International audience; In this paper we study the approximation by splitting techniques of the ordinary differential equation Udot+A U+B U=0, U(0)=U0 with A and B two matrices. We assume that we have a stiff problem in the sense that A is ill-conditionned and U0 is a vector which is the discretization of a function with a very high derivative. This situation may appear for example when we study the discretization of a partial differential equation. We prove some error estimates for two general matrices and in the stiff case, where the estimates are independent of U0 and the commutator between A and B. This paper is dedicated to Michel Crouzeix.

Published
2007
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13. Introduction

Author

Marie-Violaine Louvet and Sylvie Mikowski

Subjects
Language and Literature, History (General) and history of Europe
Abstract

Introduction

Published
2020
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14. Opening Materials

Author

Marie-Violaine Louvet and Sylvie Mikowski

Subjects
Language and Literature, History (General) and history of Europe
Abstract

Review of Irish Studies in Europe Volume 3 Issue 2 The Home Rule Crisis

Published
2020
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