Zobrazeno 1 - 10
of 132
pro vyhledávání: '"Serge Gratton"'
Publikováno v:
Journal of Advances in Modeling Earth Systems, Vol 15, Iss 4, Pp n/a-n/a (2023)
Abstract Data Assimilation aims at estimating the posterior conditional probability density functions based on error statistics of the noisy observations and the dynamical system. State of the art methods are sub‐optimal due to the common use of Ga
Externí odkaz:
https://doaj.org/article/64eb4547fc1a478da12b73d5e70cf5cf
Publikováno v:
Flow, Vol 3 (2023)
Predicting the laminar to turbulent transition is an important aspect of computational fluid dynamics because of its impact on skin friction. Traditional transition prediction methods such as local stability theory or the parabolized stability equati
Externí odkaz:
https://doaj.org/article/06f94a12a57f4f9182cf097c17932a29
Publikováno v:
EURO Journal on Computational Optimization, Vol 3, Iss 1, Pp 31-51 (2015)
We propose to use an observation-thinning method for the efficient numerical solution of large-scale incremental four- dimensional (4D-Var) data assimilation problems. This decomposition is based on exploiting an adaptive hierarchy of the observation
Externí odkaz:
https://doaj.org/article/62a298c003384283901627d22f1dae46
Publikováno v:
Journal of Algorithms & Computational Technology, Vol 3 (2009)
We present a parallel distributed solver that enables us to solve incremental dense least squares arising in some parameter estimation problems. This solver is based on ScaLAPACK [8] and PBLAS [9] kernel routines. In the incremental process, the obse
Externí odkaz:
https://doaj.org/article/9764b03f87814916baa47500fb4870e3
Publikováno v:
Mathematical Geosciences.
Autor:
Mayeul Destouches, Paul Mycek, Jérémy Briant, Selime Gürol, Anthony Weaver, Serge Gratton, Ehouarn Simon
In ensemble variational (EnVar) data assimilation systems, background error covariances are sampled from an ensemble of forecasts evolving with time. One possible way of generating this ensemble is by running an Ensemble of Data Assimilations (EDA) t
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_________::cc4052d448e034424b3fddbce56e9a3c
https://doi.org/10.5194/egusphere-egu22-336
https://doi.org/10.5194/egusphere-egu22-336
Publikováno v:
AIAA SCITECH 2022 Forum.
Publikováno v:
AIAA SCITECH 2022 Forum
AIAA SCITECH 2022 Forum, Jan 2022, San Diego, CA (virtual), United States. ⟨10.2514/6.2022-1073⟩
56th 3AF International Conference on Applied Aerodynamics (AERO 2022)
56th 3AF International Conference on Applied Aerodynamics (AERO 2022), Association Aéronautique et Astronautique de France (3AF), Mar 2022, Toulouse, France. pp.1073, ⟨10.2514/6.2022-1073⟩
AIAA SCITECH 2022 Forum, Jan 2022, San Diego, CA (virtual), United States. ⟨10.2514/6.2022-1073⟩
56th 3AF International Conference on Applied Aerodynamics (AERO 2022)
56th 3AF International Conference on Applied Aerodynamics (AERO 2022), Association Aéronautique et Astronautique de France (3AF), Mar 2022, Toulouse, France. pp.1073, ⟨10.2514/6.2022-1073⟩
International audience; View Video Presentation: https://doi.org/10.2514/6.2022-1073.vid Predicting the laminar to turbulent transition is an important aspect of computational fluid dynamics because of its impact on skin friction. The traditional met
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::fdb51dd80ebf68e5813faa2198d2bdea
https://hal.science/hal-03774047
https://hal.science/hal-03774047
We show to what extent the accuracy of the inner products computed in the GMRES iterative solver can be reduced as the iterations proceed without affecting the convergence rate or final accuracy achieved by the iterates. We bound the loss of orthogon
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::5f3cf4d7bc5f288015ef8857eaa2a298
https://ut3-toulouseinp.hal.science/hal-03637231
https://ut3-toulouseinp.hal.science/hal-03637231
Autor:
Ph. L. Toint, Serge Gratton
Publikováno v:
Computational Optimization and Applications
Computational Optimization and Applications, Springer Verlag, 2020, pp.1-15
Gratton, S & Toint, P L 2020, ' A note on solving nonlinear optimization problems in variable precision ', Computational Optimization and Applications, vol. 76, no. 3, pp. 917-933 . https://doi.org/10.1007/s10589-020-00190-2
Computational Optimization and Applications, Springer Verlag, 2020, pp.1-15
Gratton, S & Toint, P L 2020, ' A note on solving nonlinear optimization problems in variable precision ', Computational Optimization and Applications, vol. 76, no. 3, pp. 917-933 . https://doi.org/10.1007/s10589-020-00190-2
This short note considers an efficient variant of the trust-region algorithm with dynamic accuracy proposed Carter (1993) and Conn, Gould and Toint (2000) as a tool for very high-performance computing, an area where it is critical to allow multi-prec