A Robust Criterion for the Modified Gram-Schmidt Algorithm with Selective Reorthogonalization. - Luc Giraud; Julien Langou (SIAM J. Sci. Comput., 2003)

A Rank-k Update Procedure for Reorthogonalizing the Orthogonal Factor from Modified Gram-Schmidt. - Luc Giraud; Serge Gratton; Julien Langou (SIAM J. Matrix Anal. Appl., 2004)

Comparison of Nonlinear Conjugate-Gradient Methods for Computing the Electronic Properties of Nanostructure Architectures. - Stanimire Tomov; Julien Langou; Andrew Canning; Lin-Wang Wang; Jack J. Dongarra (International Conference on Computational Science (3), 2005)

Fault tolerant high performance computing by a coding approach. - Zizhong Chen; Graham E. Fagg; Edgar Gabriel; Julien Langou; Thara Angskun; George Bosilca; Jack J. Dongarra (PPoPP, 2005)

Hash Functions for Datatype Signatures in MPI. - Julien Langou; George Bosilca; Graham E. Fagg; Jack J. Dongarra (PVM/MPI, 2005)

Rounding error analysis of the classical Gram-Schmidt orthogonalization process. - Luc Giraud; Julien Langou; Miroslav Rozlozník; Jasper van den Eshof (Numerische Mathematik, 2005)

Algorithm 842: A set of GMRES routines for real and complex arithmetics on high performance computers. - Valérie Frayssé; Luc Giraud; Serge Gratton; Julien Langou (ACM Trans. Math. Softw., 2005)

Parallel Linear Algebra Software. - Victor Eijkhout; Julien Langou; Jack J. Dongarra (Parallel Processing for Scientific Computing, 2006)

Exploiting Mixed Precision Floating Point Hardware in Scientific Computations. - Alfredo Buttari; Jack J. Dongarra; Jakub Kurzak; Julie Langou; Julien Langou; Piotr Luszczek; Stanimire Tomov (High Performance Computing Workshop, 2006)

The Impact of Multicore on Math Software. - Alfredo Buttari; Jack J. Dongarra; Jakub Kurzak; Julien Langou; Piotr Luszczek; Stanimire Tomov (PARA, 2006)

Prospectus for the Next LAPACK and ScaLAPACK Libraries. - James Demmel; Jack J. Dongarra; Beresford N. Parlett; William Kahan; Ming Gu 002; David Bindel; Yozo Hida; Xiaoye S. Li; Osni Marques; E. Jason Riedy; Christof Vömel; Julien Langou; et al. (PARA, 2006)

Recent Advances in Dense Linear Algebra: Minisymposium Abstract. - Daniel Kressner; Julien Langou (PARA, 2006)

Tools and techniques for performance - Exploiting the performance of 32 bit floating point arithmetic in obtaining 64 bit accuracy (revisiting iterative refinement for linear systems). - Julie Langou; Julien Langou; Piotr Luszczek; Jakub Kurzak; Alfredo Buttari; Jack J. Dongarra (SC, 2006)

Self-adapting numerical software (SANS) effort. - Jack J. Dongarra; George Bosilca; Zizhong Chen; Victor Eijkhout; Graham E. Fagg; Erika Fuentes; Julien Langou; Piotr Luszczek; Jelena Pjesivac-Grbovic; Keith Seymour; Haihang You; Sathish S. Vadhiyar (IBM J. Res. Dev., 2006)

Conjugate-gradient eigenvalue solvers in computing electronic properties of nanostructure architectures. - Stanimire Tomov; Julien Langou; Jack J. Dongarra; Andrew Canning; Lin-Wang Wang (Int. J. Comput. Sci. Eng., 2006)

A note on the error analysis of classical Gram-Schmidt. - Alicja Smoktunowicz; Jesse L. Barlow; Julien Langou (Numerische Mathematik, 2006)

Advanced MPI Programming. - Julien Langou; George Bosilca (PVM/MPI, 2007)

A distributed packed storage for large dense parallel in-core calculations. - Marc Baboulin; Luc Giraud; Serge Gratton; Julien Langou (Concurr. Comput. Pract. Exp., 2007)

Mixed Precision Iterative Refinement Techniques for the Solution of Dense Linear Systems. - Alfredo Buttari; Jack J. Dongarra; Julie Langou; Julien Langou; Piotr Luszczek; Jakub Kurzak (Int. J. High Perform. Comput. Appl., 2007)

Performance Optimization and Modeling of Blocked Sparse Kernels. - Alfredo Buttari; Victor Eijkhout; Julien Langou; Salvatore Filippone (Int. J. High Perform. Comput. Appl., 2007)

Convergence in Backward Error of Relaxed GMRES. - Luc Giraud; Serge Gratton; Julien Langou (SIAM J. Sci. Comput., 2007)

Recovery Patterns for Iterative Methods in a Parallel Unstable Environment. - Julien Langou; Zizhong Chen; George Bosilca; Jack J. Dongarra (SIAM J. Sci. Comput., 2007)

Prospectus for a Dense Linear Algebra Software Library. - Yozo Hida; James Demmel; Julien Langou; Jakub Kurzak; Ming Gu 002; Alfredo Buttari; Stanimire Tomov; Piotr Luszczek; Julie Langou; Osni Marques; Christof Vömel; Xiaoye S. Li; et al. (Handbook of Parallel Computing, 2007)

Parallel tiled QR factorization for multicore architectures. - Alfredo Buttari; Julien Langou; Jakub Kurzak; Jack J. Dongarra (Concurr. Comput. Pract. Exp., 2008)

Communication-avoiding parallel and sequential QR factorizations - James Demmel; Laura Grigori; Mark Hoemmen; Julien Langou (CoRR, 2008)

Algorithmic Based Fault Tolerance Applied to High Performance Computing - George Bosilca; Remi Delmas; Jack J. Dongarra; Julien Langou (CoRR, 2008)

Accelerating scientific computations with mixed precision algorithms. - Marc Baboulin; Alfredo Buttari; Jack J. Dongarra; Jakub Kurzak; Julie Langou; Julien Langou; Piotr Luszczek; Stanimire Tomov (Comput. Phys. Commun., 2009)

The Problem With the Linpack Benchmark 1.0 Matrix Generator. - Jack J. Dongarra; Julien Langou (Int. J. High Perform. Comput. Appl., 2009)

Algorithm-based fault tolerance applied to high performance computing. - George Bosilca; Remi Delmas; Jack J. Dongarra; Julien Langou (J. Parallel Distributed Comput., 2009)

Computing the conditioning of the components of a linear least-squares solution. - Marc Baboulin; Jack J. Dongarra; Serge Gratton; Julien Langou (Numer. Linear Algebra Appl., 2009)

A class of parallel tiled linear algebra algorithms for multicore architectures. - Alfredo Buttari; Julien Langou; Jakub Kurzak; Jack J. Dongarra (Parallel Comput., 2009)

QR factorization of tall and skinny matrices in a grid computing environment. - Emmanuel Agullo; Camille Coti; Jack J. Dongarra; Thomas Hérault; Julien Langou (IPDPS, 2010)

Towards an Efficient Tile Matrix Inversion of Symmetric Positive Definite Matrices on Multicore Architectures. - Emmanuel Agullo; Henricus Bouwmeester; Jack J. Dongarra; Jakub Kurzak; Julien Langou; Lee Rosenberg (VECPAR, 2010)

A Critical Path Approach to Analyzing Parallelism of Algorithmic Variants. Application to Cholesky Inversion - Henricus Bouwmeester; Julien Langou (CoRR, 2010)

The Cycle-Convergence of Restarted GMRES for Normal Matrices Is Sublinear. - Eugene Vecharynski; Julien Langou (SIAM J. Sci. Comput., 2010)

Rectangular full packed format for cholesky's algorithm: factorization, solution, and inversion. - Fred G. Gustavson; Jerzy Wasniewski; Jack J. Dongarra; Julien Langou (ACM Trans. Math. Softw., 2010)

LU factorization for accelerator-based systems. - Emmanuel Agullo; Cédric Augonnet; Jack J. Dongarra; Mathieu Faverge; Julien Langou; Hatem Ltaief; Stanimire Tomov (AICCSA, 2011)

Flexible Development of Dense Linear Algebra Algorithms on Massively Parallel Architectures with DPLASMA. - George Bosilca; Aurélien Bouteiller; Anthony Danalis; Mathieu Faverge; Azzam Haidar; Thomas Hérault; Jakub Kurzak; Julien Langou; Pierre Lemarinier; Hatem Ltaief; Piotr Luszczek; Asim YarKhan; et al. (IPDPS Workshops, 2011)

Tiled QR factorization algorithms. - Henricus Bouwmeester; Mathias Jacquelin; Julien Langou; Yves Robert (SC, 2011)

QCG-OMPI: MPI applications on grids. - Emmanuel Agullo; Camille Coti; Thomas Hérault; Julien Langou; Sylvain Peyronnet; Ala Rezmerita; Franck Cappello; Jack J. Dongarra (Future Gener. Comput. Syst., 2011)

Any admissible cycle-convergence behavior is possible for restarted GMRES at its initial cycles. - Eugene Vecharynski; Julien Langou (Numer. Linear Algebra Appl., 2011)

Hierarchical QR Factorization Algorithms for Multi-core Cluster Systems. - Jack J. Dongarra; Mathieu Faverge; Thomas Hérault; Julien Langou; Yves Robert (IPDPS, 2012)

Abstract: Matrices Over Runtime Systems at Exascale. - Emmanuel Agullo; George Bosilca; Bérenger Bramas; Cedric Castagnede; Olivier Coulaud; Eric Darve; Jack J. Dongarra; Mathieu Faverge; Nathalie Furmento; Luc Giraud; Xavier Lacoste; Julien Langou; et al. (SC Companion, 2012)

Poster: Matrices over Runtime Systems at Exascale. - Emmanuel Agullo; George Bosilca; Bérenger Bramas; Cedric Castagnede; Olivier Coulaud; Eric Darve; Jack J. Dongarra; Mathieu Faverge; Nathalie Furmento; Luc Giraud; Xavier Lacoste; Julien Langou; et al. (SC Companion, 2012)

Flexible Variants of Block Restarted GMRES Methods with Application to Geophysics. - Henri Calandra; Serge Gratton; Julien Langou; Xavier Pinel; Xavier Vasseur (SIAM J. Sci. Comput., 2012)

Communication-optimal Parallel and Sequential QR and LU Factorizations. - James Demmel; Laura Grigori; Mark Hoemmen; Julien Langou (SIAM J. Sci. Comput., 2012)

Topic 10: Parallel Numerical Algorithms - (Introduction). - Julien Langou; Matthias Bolten; Laura Grigori; Marián Vajtersic (Euro-Par, 2013)

A Greedy Algorithm for Optimally Pipelining a Reduction. - Bradley R. Lowery; Julien Langou (CoRR, 2013)

Hierarchical QR factorization algorithms for multi-core clusters. - Jack J. Dongarra; Mathieu Faverge; Thomas Hérault; Mathias Jacquelin; Julien Langou; Yves Robert (Parallel Comput., 2013)

Level-3 Cholesky Factorization Routines Improve Performance of Many Cholesky Algorithms. - Fred G. Gustavson; Jerzy Wasniewski; Jack J. Dongarra; José R. Herrero 001; Julien Langou (ACM Trans. Math. Softw., 2013)

Designing LU-QR Hybrid Solvers for Performance and Stability. - Mathieu Faverge; Julien Herrmann; Julien Langou; Bradley R. Lowery; Yves Robert; Jack J. Dongarra (IPDPS, 2014)

A Makespan Lower Bound for the Scheduling of the Tiled Cholesky Factorization based on ALAP scheduling. - Willy Quach; Julien Langou (CoRR, 2015)

Mixing LU and QR factorization algorithms to design high-performance dense linear algebra solvers. - Mathieu Faverge; Julien Herrmann; Julien Langou; Bradley R. Lowery; Yves Robert; Jack J. Dongarra (J. Parallel Distributed Comput., 2015)

Bidiagonalization with Parallel Tiled Algorithms. - Mathieu Faverge; Julien Langou; Yves Robert; Jack J. Dongarra (CoRR, 2016)

A backward/forward recovery approach for the preconditioned conjugate gradient method. - Massimiliano Fasi; Julien Langou; Yves Robert; Bora Uçar (J. Comput. Sci., 2016)

Fast Parallel Randomized QR with Column Pivoting Algorithms for Reliable Low-Rank Matrix Approximations. - Jianwei Xiao; Ming Gu 002; Julien Langou (HiPC, 2017)

Bidiagonalization and R-Bidiagonalization: Parallel Tiled Algorithms, Critical Paths and Distributed-Memory Implementation. - Mathieu Faverge; Julien Langou; Yves Robert; Jack J. Dongarra (IPDPS, 2017)

Low synchronization GMRES algorithms. - Kasia Swirydowicz; Julien Langou; Shreyas Ananthan; Ulrike Meier Yang; Stephen J. Thomas (CoRR, 2018)

A Makespan Lower Bound for the Tiled Cholesky Factorization Based on ALAP Schedule. - Olivier Beaumont; Julien Langou; Willy Quach; Alena Shilova (Euro-Par, 2020)

A Comparison of Several Fault-Tolerance Methods for the Detection and Correction of Floating-Point Errors in Matrix-Matrix Multiplication. - Valentin Le Fèvre; Thomas Hérault; Julien Langou; Yves Robert (Euro-Par Workshops, 2020)

Automated derivation of parametric data movement lower bounds for affine programs. - Auguste Olivry; Julien Langou; Louis-Noël Pouchet; P. Sadayappan; Fabrice Rastello (PLDI, 2020)

Low synchronization Gram-Schmidt and generalized minimal residual algorithms. - Katarzyna Swirydowicz; Julien Langou; Shreyas Ananthan; Ulrike Meier Yang; Stephen J. Thomas (Numer. Linear Algebra Appl., 2021)

Proposed Consistent Exception Handling for the BLAS and LAPACK. - James Demmel; Jack J. Dongarra; Mark Gates; Greg Henry; Julien Langou; Xiaoye S. Li; Piotr Luszczek; Weslley S. Pereira; E. Jason Riedy; Cindy Rubio-González (Correctness@SC, 2022)

Symmetric Block-Cyclic Distribution: Fewer Communications Leads to Faster Dense Cholesky Factorization. - Olivier Beaumont; Philippe Duchon; Lionel Eyraud-Dubois; Julien Langou; Mathieu Vérité (SC, 2022)

I/O-Optimal Algorithms for Symmetric Linear Algebra Kernels. - Olivier Beaumont; Lionel Eyraud-Dubois; Julien Langou; Mathieu Vérité (SPAA, 2022)

Numerical analysis of Givens rotation. - Weslley da Silva Pereira; Ali Lotfi; Julien Langou (CoRR, 2022)

Low-synch Gram-Schmidt with delayed reorthogonalization for Krylov solvers. - Daniel Bielich; Julien Langou; Stephen J. Thomas; Kasia Swirydowicz; Ichitaro Yamazaki; Erik G. Boman (Parallel Comput., 2022)

Tightening I/O Lower Bounds through the Hourglass Dependency Pattern. - Lionel Eyraud-Dubois; Guillaume Iooss; Julien Langou; Fabrice Rastello (SPAA, 2024)

Probabilistic Analysis of Least Squares, Orthogonal Projection, and QR Factorization Algorithms Subject to Gaussian Noise. - Ali Lotfi; Julien Langou; Mohammad Meysami (CoRR, 2024)

Communication efficient application of sequences of planar rotations to a matrix. - Thijs Steel; Julien Langou (CoRR, 2024)

A new deflation criterion for the QZ algorithm. - Thijs Steel; Raf Vandebril; Julien Langou (Numer. Linear Algebra Appl., 2024)

2024 NSF CSSI-Cybertraining-SCIPE PI Meeting August 12 to 13, 2024, Charlotte, NC. - Abani K. Patra; Mary P. Thomas; Elias Bou-Harb; Jeffrey C. Carver; Yuebin Guo; Ratnesh Kumar; Julien Langou; Guoyu Lu; Vivak Patel; Marianna Safronova; Isla Simpson; Dhruva Chakravorty; et al. (CoRR, 2025)