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[JOB] Postdoc at CEA Cadarache 👩‍💻🧑‍💻- Autotuning for ultra-high performance computing with partitioned coupling




Taking into account multiple and coupled physics is at the heart of many application needs in fields as varied as, but not limited to, aeronautics, defense and biology. This is also strong area of expertise for CEA’s Energy Division, with multiple domains including fluid-structure interaction, neutronics coupled with thermal-hydraulics a/o thermal-mechanics or severe accident modeling. The emergence of exascale architectures opens the way to promising new levels of high-fidelity simulations, but is also significantly increasing the complexity of many software applications in terms of total or partial rewriting. It therefore specifically encourages coupling to limit development work. The idea is to search for each physics of interest in a necessarily reduced number of highly optimized software components, rather than making specific, possibly redundant developments in standalone applications.
Once the coupled multiphysics problem has been written with the expected levels of accurracy and stability, the proposed work concentrates on the resolution algorithms to enable the coupling between applications asssumed to be themselves exascale-compatible, to be solved efficiently at exascale. It is also worth noting that, in general, the couplings under consideration can present a high level of complexity, involving numerous physics with different level of feedback between them and various communications from border exchanges to overlaping domains. The current post-doctoral internship to be carried out in the framework of the ExaMA collaborative project, is in particular dedicated to the identification and dynamic tuning of the relevant numerical parameters arising from the coupling algorithms and impacting the computational efficiency of the global simulation. Considered problems are in the general case time-evolving problems, with a significant number of time iterations allowing using the first iterations to gather data and conduct the tuning.

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[JOB] PostDoc at LIP6 👩‍💻🧑‍💻- Precision auto-tuning and numerical validation of high performance simulations


This PostDoc will be carried out in the framework of the PEPR (Programme et Equipement Prioritaire de Recherche) NumPEx project devoted to High Performance Numerics for the Exascale and financed by the France2030 investment program.

Research directions

During this PostDoc several directions will be explored to improve algorithms for precision auto-tuning and numerical validation.

We plan to design a novel autotuning algorithm that will automatically provide arbitrary precision codes, from a required accuracy on the computed results. Because of the number of possible type configurations, particular attention will be paid to the algorithm performance. The type configuration produced will then enable one to improve storage cost, and also execution time taking into account the numerical formats available on the target architectures.

We plan to combine mixed precision algorithms and precision autotuning tools. Such automatic tools may be useful in the design of mixed precision linear algebra algorithms. Conversely the performance of precision autotuning tools may be improved thanks to mixed precision algorithms. Linear algebra kernels could be automatically identified in simulation codes, and replaced by their mixed precision version, in order to reduce the exploration space for precision tuning.

The precision auto-tuning algorithms designed during this PostDoc will be validated on large scale programs developed by partners of the NumPEx project. Furthermore new methodologies will be proposed to perform autotuning of both numerical formats and performance parameters in collaboration with experts in coupled physics simulations.


Sorbonne Université and its Computer Science lab LIP6 are settled on the Pierre & Marie Curie Campus in the Latin Quarter of Paris, France.


The gross salary per month (including national health insurance and employment insurance) varies from 2682 to 3701 euros depending on the experience.


1 year, renewable 1 year

Qualifications and skills

Candidates must have a PhD in Computer Science, Applied Mathematics or other relevant fields, with good programming skills. Developments will be carried out in C++ and Python, so programming expertise in at least one of these languages is required. Good knowledge in numerical algorithms and floating-point computation is also required.

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[JOB] Two postdoctoral positions for the modeling of alkaline electrolysis

Join the CEA/TotalEnergies collaboration DAWN, and contribute to the development of a digital twin for the production of green dihydrogen with alkaline electrolysers. We are recruiting two postdoctoral researchers to develop the numerical tools Flower and canoP for a period of 2 years to work at our CEA Saclay site near Paris.

To apply, please send your application (resume and cover letter) to Pascal Tremblin and Taraneh Sayadi. You can use the same addresses for any questions concerning the offer. Applications will be evaluated until the positions are filled.