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NESAP Postdocs

Since introducing the NERSC Exascale Scientific Applications Program (NESAP) in 2015, NERSC has hired six postdoctoral fellows and placed them with NESAP code optimization teams. The postdocs are working in multidisciplinary teams composed of computer scientists, applied mathematicians, domain scientists and performance optimization experts that are helping NERSC users transition codes to the Cori system.

NESAP Postdocs

From left: Taylor Barnes, Mathieu Lobet, Tuomas Koskela. Not pictured: Brian Friesen, Tareq Malas, Andrey Ovsyannikov


The first six NESAP postdocs are Taylor Barnes, Brian Friesen, Tuomas Koskela, Mathieu Lobet, Tareq Malas and Andrey Ovsyannikov.

  • Taylor Barnes is NERSC’s Rear Admiral Grace Murray Hopper Postdoctoral Fellow. As part of the NESAP program, he is working with Jack Deslippe, acting group lead for the Applications Performance Group at NERSC, and David Prendergast of the Molecular Foundry to prepare Quantum Espresso, an electronic-structure code for materials modeling at the nanoscale, for application on manycore architectures. Barnes received his Ph.D. in chemistry from The California Institute of Technology in 2015, where his research focused on the development of embedding methods for the efficient and accurate simulation of molecular systems.
  • Brian Friesen, who is now a staff member in NERSC’s Application Performance Group, received his Ph.D. in physics from the University of Oklahoma in 2015, where his research focused on radiative transfer calculations in supernovae. He joined NERSC as the first NESAP postdoc in May 2015, working with Ann Almgren’s group in Berkeley Lab’s Center for Computational Sciences and Engineering to make improvements to BoxLib, an adaptive mesh refinement framework used in a variety of scientific codes.
  • Tuomas Koskela joined NERSC in January 2016 and is working with Choong-Seock Chang’s group (Princeton Plasma Physics Laboratory) on their NESAP project, “Understanding Fusion Edge Physics Using the Global Gyrokinetic XGC1 Code.” Koskela got his PhD degree in applied physics from Aalto University in 2015; his thesis work was on Monte Carlo modelling of fast ion confinement in Tokamak fusion reactors under 3D magnetic perturbations. Koskela spent the last two years of his Ph.D. at the JET experiment at CCFE and stayed there as a postdoc for another year after completing his Ph.D. At CCFE, he worked on integrated whole-device modelling with a combination of reduced models and first-principles codes.
  • Mathieu Lobet joined NERSC as a NESAP postdoc in January 2016. He is now working on performance optimization of the particle-in-cell code WARP in collaboration with Jean-Luc Vay and Berkeley Lab’s BELLA program. Lobet graduated in 2012 in mathematical and mechanics modeling from the ENSEIRB-MATMECA engineering school in Bordeaux, with specializations in fluid dynamics, plasma physics, numerical analysis and high performance computing. He obtained his Ph.D. in 2015 focused on physics of laser-matter interaction and numerical simulation. He did his Ph.D. studies at the CEA near Paris in collaboration with the CELIA laboratory. His Ph.D. work was about the theoretical and the numerical study of the radiative and quantum electrodynamics effects in extremely intense laser-matter interaction.
  • Tareq Malas joined the NESAP postdoc group in January 2016, where he is working with Greg Newman and Petr Petrov from Berkeley Lab’s Earth & Environmental Sciences to port Geophysical Inverse Modeling applications for Cori. He obtained his MS and Ph.D. degrees from King Abdullah University of Science and Technology in Saudi Arabia. His interests include developing efficient high performance computing algorithms on contemporary and future architectures for the most demanding applications.
  • Andrey Ovysannikov joined NERSC as a NESAP postdoc in July 2015 and is working with David Trebotich at Berkeley Lab on performance optimization of Chombo-Crunch, a subsurface flow with reactive transport code used for modeling carbon sequestration and other science applications. Ovsyannikov graduated in Applied Math in 2009 from Novosibirsk State University and obtained his Ph.D. in fluid mechanics in 2013 from Ecole Centrale de Lyon. His Ph.D. work focused on development of numerical algorythms for simulations of two-phase liquid-gas flows. After completing his Ph.D. Andrey moved to the U.S. where he started his postdoc in the Center for Turbulence Research at Stanford University. That work involved numerical study of turbulent bubbly flows which occur near ship walls.