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Alfredo Buttari

CNRS Research Director at IRIT
71
Documents

Présentation

I am currently a CNRS (Centre National de la Recherche Scientifique) research director at the IRIT (Institut de Recherche en Informatique de Toulouse) laboratory in Toulouse (France) where I am a member of the APO (Algorithmes Parallèles et Optimisation). My interest are in High Performance Computing, parallel computing, computational linear algebra (numerical software in general). Here is my CV and a short bio: - 2021-present: CNRS research director @ IRIT - 2008-2021: CNRS researcher @ IRIT - 2018: Habilitation à Diriger des Recherches (manuscript, presentation). - 2008: post-doc at INRIA Rhone-Alpes in Lyon (France) where I was a member of the Laboratoire de l'Informatique du Parallelisme (LIP). - 2006-2007: post-doc in the Innovative Computing Laboratory (ICL) lead by Prof. Jack Dongarra at the University of Tennessee Knoxville. - 2003-2006 Ph.D. at Dipartimento Informatica Sistemi e Produzione of University of Rome "Tor Vergata". More info on my web page: https://abuttari.gitlab.io

Publications

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Communication Avoiding Block Low-Rank Parallel Multifrontal Triangular Solve with Many Right-Hand Sides

Patrick Amestoy , Olivier Boiteau , Alfredo Buttari , Matthieu Gerest , Fabienne Jézéquel
SIAM Journal on Matrix Analysis and Applications, 2024, 45 (1), pp.148-166. ⟨10.1137/23M1568600⟩
Article dans une revue hal-04082415v1
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Combining sparse approximate factorizations with mixed precision iterative refinement

Patrick Amestoy , Alfredo Buttari , Nicholas J Higham , Jean-Yves L’excellent , Théo Mary
ACM Transactions on Mathematical Software, inPress, 49 (1), pp.1-29. ⟨10.1145/3582493⟩
Article dans une revue hal-03536031v1
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Is 3D frequency-domain FWI of full-azimuth/long-offset OBN data feasible? The Gorgon case study

Stéphane Operto , Patrick Amestoy , Stephen Beller , Alfredo Buttari , L. Combe
Leading Edge, 2023, 42 (3), pp.173-183. ⟨10.1190/tle42030173.1⟩
Article dans une revue hal-03922986v1
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Task-based parallel programming for scalable matrix product algorithms

Emmanuel Agullo , Alfredo Buttari , Abdou Guermouche , Julien Herrmann , Antoine Jego
ACM Transactions on Mathematical Software, 2023, ⟨10.1145/3583560⟩
Article dans une revue hal-03936659v2
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Five-Precision GMRES-based iterative refinement

Patrick Amestoy , Alfredo Buttari , Nicholas Higham , Jean-Yves L'Excellent , Théo Mary
SIAM Journal on Matrix Analysis and Applications, In press
Article dans une revue hal-03190686v1
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Mixed Precision Low Rank Approximations and their Application to Block Low Rank LU Factorization

Patrick Amestoy , Olivier Boiteau , Alfredo Buttari , Matthieu Gerest , Fabienne Jézéquel
IMA Journal of Numerical Analysis, 2022, ⟨10.1093/imanum/drac037⟩
Article dans une revue hal-03251738v3
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Block Low-rank Single Precision Coarse Grid Solvers for Extreme Scale Multigrid Methods

Alfredo Buttari , Markus Huber , Philippe Leleux , Théo Mary , Ulrich Ruede
Numerical Linear Algebra with Applications, 2021, 29 (1), ⟨10.1002/nla.2407⟩
Article dans une revue hal-02528532v1
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Block Low-Rank Matrices with Shared Bases: Potential and Limitations of the BLR2S Format

Cleve Ashcraft , Alfredo Buttari , Théo Mary
SIAM Journal on Matrix Analysis and Applications, 2021, 42 (2), ⟨10.1137/20M1386451⟩
Article dans une revue hal-03070416v2
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Parallel QR factorization of block-tridiagonal matrices

Alfredo Buttari , Søren Hauberg , Costy Kodsi
SIAM Journal on Scientific Computing, 2020, 42 (6), pp.C313-C334. ⟨10.1137/19M1306166⟩
Article dans une revue hal-02370953v2
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A Tridiagonalization Method for Symmetric Saddle-Point Systems

Alfredo Buttari , Dominique Orban , Daniel Ruiz , David Titley-Peloquin
SIAM Journal on Scientific Computing, 2019, 41 (5), pp.S409-S432. ⟨10.1137/18M1194900⟩
Article dans une revue hal-02343661v1
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Performance and Scalability of the Block Low-Rank Multifrontal Factorization on Multicore Architectures

Patrick Amestoy , Alfredo Buttari , Jean-Yves L'Excellent , Théo Mary
ACM Transactions on Mathematical Software, 2019, 45 (1), pp.1-23. ⟨10.1145/3242094⟩
Article dans une revue hal-01955766v2
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Bridging the gap between flat and hierarchical low-rank matrix formats: the multilevel BLR format

Patrick Amestoy , Alfredo Buttari , Jean-Yves L'Excellent , Théo Mary
SIAM Journal on Scientific Computing, 2019, 41 (3), pp.A1414-A1442. ⟨10.1137/18M1182760⟩
Article dans une revue hal-01774642v3
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On the Complexity of the Block Low-Rank Multifrontal Factorization

Patrick Amestoy , Alfredo Buttari , Jean-Yves L'Excellent , Théo Mary
SIAM Journal on Scientific Computing, 2017, 39 (4), pp.34. ⟨10.1137/16M1077192⟩
Article dans une revue hal-01322230v3
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Large-scale 3D EM modeling with a Block Low-Rank multifrontal direct solver

Daniil Shantsev , Piyoosh Jaysaval , Sébastien de La Kethulle de Ryhove , Patrick Amestoy , Alfredo Buttari
Geophysical Journal International, 2017, 209 (3), pp.1558-1571. ⟨10.1093/gji/ggx106⟩
Article dans une revue hal-01672952v1

Fast 3D frequency-domain full waveform inversion with a parallel Block Low-Rank multifrontal direct solver: application to OBC data from the North Sea

Patrick Amestoy , Romain Brossier , Alfredo Buttari , Jean-Yves L'Excellent , Théo Mary
Geophysics, 2016, 81 (6), pp.R363-R383. ⟨10.1190/geo2016-0052.1⟩
Article dans une revue hal-01349119v1
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Implementing multifrontal sparse solvers for multicore architectures with Sequential Task Flow runtime systems

Emmanuel Agullo , Alfredo Buttari , Abdou Guermouche , Florent Lopez
ACM Transactions on Mathematical Software, 2016, ⟨10.1145/2898348⟩
Article dans une revue hal-01333645v1
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Robust memory-aware mappings for parallel multifrontal factorizations

Emmanuel Agullo , Patrick Amestoy , Alfredo Buttari , Abdou Guermouche , Jean-Yves L'Excellent
SIAM Journal on Scientific Computing, 2016, 38 (3), pp.C256 - C279. ⟨10.1137/130938505⟩
Article dans une revue hal-01334113v2

Mixed Precision Iterative Refinement Techniques for the Solution of Dense Linear Systems

Alfredo Buttari , Jack J. Dongarra , Julie Langou , Julien Langou , Piotr Luszczek
International Journal of High Performance Computing Applications, 2016, 21 (4), pp.457-466. ⟨10.1177/1094342007084026⟩
Article dans une revue hal-02421121v1

Performance Optimization and Modeling of Blocked Sparse Kernels

Alfredo Buttari , Victor Eijkhout , Julien Langou , Salvatore Filippone
International Journal of High Performance Computing Applications, 2016, 21 (4), pp.467-484. ⟨10.1177/1094342007083801⟩
Article dans une revue hal-02421133v1

Improving Multifrontal Methods by Means of Block Low-Rank Representations

Patrick Amestoy , Cleve Ashcraft , Olivier Boiteau , Alfredo Buttari , Jean-Yves L'Excellent
SIAM Journal on Scientific Computing, 2015, 37 (3), pp.A1451-A1474. ⟨10.1137/120903476⟩
Article dans une revue hal-01237169v1
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Shared memory parallelism and low-rank approximation techniques applied to direct solvers in FEM simulation

Patrick Amestoy , Alfredo Buttari , Guillaume Joslin , Jean-Yves L'Excellent , Mohamed Sid-Lakhdar
IEEE Transactions on Magnetics, 2014, vol. 50 (n° 2), pp. 1-4. ⟨10.1109/TMAG.2013.2284024⟩
Article dans une revue hal-01123557v1
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INTEGRAL/SPI data segmentation to retrieve sources intensity variations

Laurent Bouchet , Patrick Amestoy , Alfredo Buttari , François-Henry Rouet , Maxime Chauvin
Astronomy and Astrophysics - A&A, 2013, vol. 555 (n° A55), pp. 1-22. ⟨10.1051/0004-6361/201219605⟩
Article dans une revue hal-01124774v1
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Fine-Grained Multithreading for the Multifrontal QR Factorization of Sparse Matrices

Alfredo Buttari
SIAM Journal on Scientific Computing, 2013, vol. 35 (n° 4), pp. 323-345. ⟨10.1137/110846427⟩
Article dans une revue hal-01122471v1
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Simultaneous analysis of large INTEGRAL/SPI datasets: optimizing the computation of the solution and its variance using sparse matrix algorithms

Laurent Bouchet , Patrick Amestoy , Alfredo Buttari , François-Henry Rouet , Maxime Chauvin
Astronomy and Computing, 2013, vol. 1, pp. 59-69. ⟨10.1016/j.ascom.2013.03.002⟩
Article dans une revue hal-01125193v1
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Object-Oriented Techniques for Sparse Matrix Computations in Fortran 2003

Salvatore Filippone , Alfredo Buttari
ACM Transactions on Mathematical Software, 2012, 38 (4), pp.1-20. ⟨10.1145/2331130.2331131⟩
Article dans une revue hal-02419121v1

A class of parallel tiled linear algebra algorithms for multicore architectures

Alfredo Buttari , Julien Langou , Jakub Kurzak , Jack J. Dongarra
Parallel Computing, 2009, 35 (1), pp.38-53. ⟨10.1016/j.parco.2008.10.002⟩
Article dans une revue hal-02420965v1

Accelerating scientific computations with mixed precision algorithms

Marc Baboulin , Alfredo Buttari , Jack J. Dongarra , Jakub Kurzak , Julie Langou
Computer Physics Communications, 2009, 180 (12), pp.2526-2533. ⟨10.1016/j.cpc.2008.11.005⟩
Article dans une revue hal-02420940v1

Solving Systems of Linear Equations on the CELL Processor Using Cholesky Factorization

Jakub Kurzak , Alfredo Buttari , Jack Dongarra
IEEE Transactions on Parallel and Distributed Systems, 2008, 19 (9), pp.1175-1186. ⟨10.1109/TPDS.2007.70813⟩
Article dans une revue hal-02421046v1

Parallel tiled QR factorization for multicore architectures

Alfredo Buttari , Julien Langou , Jakub Kurzak , Jack Dongarra
Concurrency and Computation: Practice and Experience, 2008, 20 (13), ⟨10.1002/cpe.v20:13⟩
Article dans une revue hal-02421078v1

The PlayStation 3 for High-Performance Scientific Computing

Jakub Kurzak , Alfredo Buttari , Piotr Luszczek , Jack J. Dongarra
Computing in Science and Engineering, 2008, 10 (3), pp.84-87. ⟨10.1109/MCSE.2008.85⟩
Article dans une revue hal-02421063v1

Using Mixed Precision for Sparse Matrix Computations to Enhance the Performance while Achieving 64-bit Accuracy

Alfredo Buttari , Jack J. Dongarra , Jakub Kurzak , Piotr Luszczek , Stanimir Tomov
ACM Transactions on Mathematical Software, 2008, 34 (4), pp.1-22. ⟨10.1145/1377596.1377597⟩
Article dans une revue hal-02421028v1

2LEV-D2P4: a package of high-performance preconditioners for scientific and engineering applications

Alfredo Buttari , Pasqua D’ambra , Daniela Di Serafino , Salvatore Filippone
Applicable Algebra in Engineering, Communication and Computing, 2007, 18 (3), pp.223-239. ⟨10.1007/s00200-007-0035-z⟩
Article dans une revue hal-02421066v1
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On the Arithmetic Intensity of Distributed-Memory Dense Matrix Multiplication Involving a Symmetric Input Matrix (SYMM)

Emmanuel Agullo , Alfredo Buttari , Olivier Coulaud , Lionel Eyraud-Dubois , Mathieu Faverge
IPDPS 2023 - 37th International Parallel and Distributed Processing Symposium, IEEE, May 2023, St. Petersburg, FL, United States. pp.357-367
Communication dans un congrès hal-04093162v1

Vers un solveur direct à base de tâches pour des systèmes linéaires FEM/BEM creux/denses

Emmanuel Agullo , Alfredo Buttari , Marek Felšöci , Guillaume Sylvand
ComPAS 2023 - Conférence francophone d'informatique en Parallélisme, Architecture et Système, LISTIC : Laboratoire d’Informatique, Systèmes, Traitement de l’Information et de la Connaissance, de l’Université Savoie Mont Blanc., Jul 2023, Annecy, France
Communication dans un congrès hal-04178064v1

Reducing communications and memory costs of parallel Block Low-Rank solvers

Patrick Amestoy , Olivier Boiteau , Alfredo Buttari , Matthieu Gerest , Fabienne Jézéquel
SIAM Conference on Computational Science and Engineering (CSE 2023), Feb 2023, Amsterdam, Netherlands
Communication dans un congrès hal-03922334v1

Solving linear systems efficiently using block low-rank compression in mixed precision

Patrick Amestoy , Olivier Boiteau , Alfredo Buttari , Matthieu Gerest , Fabienne Jézéquel
45ème Congrès National d'Analyse Numérique (CANUM 2022), Jun 2022, Évian-les-Bains, France
Communication dans un congrès hal-03922287v1

Mixed precision sparse direct solver applied to 3D wave propagation

Patrick Amestoy , Alfredo Buttari , Florian Faucher , Jean-Yves L'Excellent , Matthieu Gerest
8th European Congress on Computational Methods in Applied Sciences and Engineering (ECCOMAS 2022), Jun 2022, Oslo, Norway
Communication dans un congrès hal-03887660v1

Solving linear systems efficiently using mixed-precision Block Low-Rank compression

Patrick Amestoy , Olivier Boiteau , Alfredo Buttari , Matthieu Gerest , Fabienne Jézéquel
Rencontres Arithmétique de l'informatique Mathématique (RAIM 2021), GdR GdR IM : Informatique Mathématique, May 2021, Paris, France
Communication dans un congrès hal-03783037v1

Simulation of a Sparse Direct Solver on Heterogeneous Systems using Starpu and Simgrid

Emmanuel Agullo , Alfredo Buttari , Abdou Guermouche , Arnaud Legrand , Ian Masliah
SIAM Conference on Computational Science and Engineering (CSE 2019), Feb 2019, Spokane, United States
Communication dans un congrès hal-02073725v1

A Tridiagonalization Method for Symmetric and Quasi-Definite Saddle-Point Systems (CM 2018, Colorado, USA)

Alfredo Buttari , Dominique Orban , Daniel Ruiz , David Titley-Peloquin
15th Copper Mountain Conference On Iterative Methods (CM 2018), Front Range Scientific Computations, Inc, Boulder, Colorado; University of Colorado, Sandia National Labs; Emory University; Society for Industrial and Applied Mathematics: SIAM Activity Group on Linear Algebra, Mar 2018, Copper Mountain, Colorado, United States
Communication dans un congrès hal-03023422v1
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Pre-exascale Architectures: OpenPOWER Performance and Usability Assessment for French Scientific Community

Gabriel Hautreux , Alfredo Buttari , Arnaud Beck , Victor Cameo , Dimitri Lecas
ISC High Performance 2017: High Performance Computing, 2017, Frankfurt, Germany. pp.309-324, ⟨10.1007/978-3-319-67630-2_23⟩
Communication dans un congrès hal-02129651v1
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Exploiting a Parametrized Task Graph model for the parallelization of a sparse direct multifrontal solver

Emmanuel Agullo , George Bosilca , Alfredo Buttari , Abdou Guermouche , Florent Lopez
Euro-Par 2016: Parallel Processing Workshops, Aug 2016, Grenoble, France. ⟨10.1007/978-3-319-58943-5_14⟩
Communication dans un congrès hal-01337748v1

3D frequency-domain seismic modeling with a Parallel BLR multifrontal direct solver

Patrick Amestoy , Romain Brossier , Alfredo Buttari , Jean-Yves L'Excellent , Théo Mary
SEG Annual meeting, Oct 2015, New Orleans, United States. pp.3606-3611
Communication dans un congrès hal-01237869v1

Efficient 3D frequency-domain full-waveform inversion of ocean-bottom cable data with sparse block low-rank direct solver: a real data case study from the North Sea

Patrick Amestoy , Romain Brossier , Alfredo Buttari , Jean-Yves L'Excellent , Théo Mary
SEG Annual meeting, Oct 2015, New Orleans, United States. pp.1303-1308, ⟨10.1190/segam2015-5713962.1⟩
Communication dans un congrès hal-01239896v1
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Fast and Accurate Simulation of Multithreaded Sparse Linear Algebra Solvers

Luka Stanisic , Emmanuel Agullo , Alfredo Buttari , Abdou Guermouche , Arnaud Legrand
The 21st IEEE International Conference on Parallel and Distributed Systems, Dec 2015, Melbourne, Australia
Communication dans un congrès hal-01180272v2

Task-based multifrontal QR solver for GPU-accelerated multicore architectures

Emmanuel Agullo , Alfredo Buttari , Abdou Guermouche , Florent Lopez
22rd IEEE International Conference on High Performance Computing (HiPC 2015), Dec 2015, Bangalore, India. ⟨10.1109/HiPC.2015.27⟩
Communication dans un congrès hal-01270145v1

Shared memory parallelism and low-rank approximation techniques applied to direct solvers in FEM simulation (regular paper)

Patrick Amestoy , Olivier Boiteau , Alfredo Buttari , Guillaume Joslin , Jean-Yves L'Excellent
19th IEEE International Conference on the Computation of Electromagnetic Fields (COMPUMAG 2013), International Compumag Society (ICS) Technical Co-Sponsorship - IEEE Magnetics Society, Jun 2013, Budapest, Hungary
Communication dans un congrès hal-00924660v1
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Multifrontal QR Factorization for Multicore Architectures over Runtime Systems

Emmanuel Agullo , Alfredo Buttari , Abdou Guermouche , Florent Lopez
19th International Conference on Parallel Processing (EuroPar 2013), Aug 2013, Aachen, Germany. pp.521-532, ⟨10.1007/978-3-642-40047-6_53⟩
Communication dans un congrès hal-01220611v1

3D frequency-domain seismic modeling with a Block Low-Rank algebraic multifrontal direct solver

Clément Weisbecker , Patrick Amestoy , Olivier Boiteau , Romain Brossier , Alfredo Buttari
Society of Exploration Geophysicists annual meeting (SEG 2013), Society of Exploration Geophysicists, 2013, Houston, Texas, United States. ⟨10.1190/segam2013-0603.1⟩
Communication dans un congrès hal-00924638v1
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Recent advances in sparse direct solvers

Emmanuel Agullo , Patrick Amestoy , Alfredo Buttari , Abdou Guermouche , Guillaume Joslin
22nd International Conference on Structural Mechanics in Reactor Technology (SMiRT 2013), Aug 2013, San Francisco, United States. pp.1-10
Communication dans un congrès hal-01060301v1

Improving Multifrontal methods by means of Low-Rank Approximations techniques

Patrick Amestoy , Cleve Ashcraft , Olivier Boiteau , Alfredo Buttari , Jean-Yves L'Excellent
SIAM Conference on Applied Linear Algebra 2012, Jun 2012, Valencia, Spain. pp.A1451-A1474
Communication dans un congrès hal-00789684v1

Robust Memory-Aware Mappings for Parallel Multifrontal Factorizations

Emmanuel Agullo , Patrick Amestoy , Alfredo Buttari , Abdou Guermouche , Jean-Yves L'Excellent
SIAM Conference on Parallel Processing for Scientific Computing (SIAM PP 2012), SIAM Activity Group on Supercomputing, Feb 2012, Savannah, Georgia, United States
Communication dans un congrès hal-00726644v1

Exploiting Multithreaded Tree Parallelism for Multicore Systems in a Parallel Multifrontal Solver

Patrick Amestoy , Alfredo Buttari , Abdou Guermouche , Jean-Yves L'Excellent , Mohamed W. Sid-Lakhdar
SIAM Conference on Parallel Processing for Scientific Computing (SIAM PP12 2012), Feb 2012, Savannah, GA, United States
Communication dans un congrès hal-00789698v1
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A Novel Aggregation Method based on Graph Matching for Algebraic MultiGrid Preconditioning of Sparse Linear Systems

Pasqua d'Ambra , Alfredo Buttari , Daniela Di Serafino , Salvatore Filippone , Simone Gentile
International Conference On Preconditioning Techniques For Scientific And Industrial Applications (PRECONDITIONING 2011), INRIA Bordeaux Sud-Ouest; ENSEIRB; University of Bordeaux 1, May 2011, Bordeaux, France
Communication dans un congrès inria-00580434v1
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Grouping variables in Frontal Matrices to improve Low-Rank Approximations in a Multifrontal Solver

Clément Weisbecker , Patrick Amestoy , Cleve Ashcraft , Olivier Boiteau , Alfredo Buttari
International Conference On Preconditioning Techniques For Scientific And Industrial Applications (PRECONDITIONING 2011), INRIA Bordeaux Sud-Ouest; ENSEIRB; University of Bordeaux 1, May 2011, Bordeaux, France
Communication dans un congrès inria-00581561v1

Towards a parallel analysis phase for a multifrontal sparse solver

Patrick Amestoy , Alfredo Buttari , Jean-Yves L'Excellent
5th International Workshop on Parallel Matrix Algorithms and Applications (PMAA 2008), Jun 2008, Neuchâtel, Switzerland
Communication dans un congrès hal-00803488v1

The minimum degree ordering with dynamical constraints

Patrick Amestoy , Alfredo Buttari , Abdou Guermouche , Jean-Yves L'Excellent , Bora Uçar
Markus Beckers; Johannes Lotz; Viktor Mosenkis; Uwe Naumann. Abstracts of the 5th SIAM Workshop on Combinatorial Scientific Computing, SIAM, pp.36-38, 2011, Technical Report
Chapitre d'ouvrage hal-00945083v1

MUMPS

Patrick Amestoy , Alfredo Buttari , Iain S. Duff , Abdou Guermouche , Jean-Yves L'Excellent
David Padua. Encyclopedia of Parallel Computing, Springer, pp.1232-1238, 2011, 978-0-387-09766-4. ⟨10.1007/978-0-387-09766-4_204⟩
Chapitre d'ouvrage hal-00787042v1

The Multifrontal Method

Patrick Amestoy , Alfredo Buttari , Iain S. Duff , Abdou Guermouche , Jean-Yves L'Excellent
David Padua. Encyclopedia of Parallel Computing, Springer, pp.1209-1216, 2011, 978-0-387-09765-7. ⟨10.1007/978-0-387-09766-4_86⟩
Chapitre d'ouvrage hal-00787015v1
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Scalability of parallel sparse direct solvers: methods, memory and performance

Alfredo Buttari
Distributed, Parallel, and Cluster Computing [cs.DC]. Toulouse INP, 2018
HDR tel-01913033v1