Current projects

FASTLA - Fast and Scalable Hierarchical Algorithms for Computational Linear Algebra

Title: Fast and Scalable Hierarchical Algorithms for Computational Linear Algebra

Grant: Inria Associated Team

Inria principal investigator: Olivier Coulaud

Partners: Stanford University (United States) - Institute for Computational and Mathematical Engineering - Eric Darve Lawrence Berkeley National Laboratory (United States) - Scientific Computing Group - Esmond Ng

Duration: 2012 - 2014

Web Site: Web site

Overview: In this project, we propose to study fast and scalable hierarchical numerical kernels and their implementations on heterogeneous manycore platforms for two major computational kernels in intensive challenging applications. Namely, fast multipole methods (FMM) and sparse hybrid linear solvers, that appear in many intensive numerical simulations in computational sciences. Regarding the FMM we plan to study novel generic formulations based on H-matrices techniques, that will be eventually validated in the field of material physics: the dislocation dynamics. For the hybrid solvers, new parallel preconditioning approaches will be designed and the use of H-matrices techniques will be first investigated in the framework of fast and monitored approximations on central components. Finally, the innovative algorithmic design will be essentially focused on heterogeneous manycore platforms. The partners, Inria HiePACS, Lawrence Berkeley Nat. Lab and Stanford University, have strong, complementary and recognized experiences and backgrounds in these fields.

Title: OPTImisation d'un code de dynamique des DISlocations

Grant: ANR-COSINUS

Partners: CEA/DEN/DMN/SRMA (leader), SIMaP Grenoble INP and ICMPE / Paris-Est.

Duration: 2010 – 2014

Overview: Plastic deformation is mainly accommodated by dislocations glide in the case of crystalline materials. The behavior of a single dislocation segment is perfectly understood since 1960 and analytical formulations are available in the literature. However, to understand the behavior of a large population of dislocations (inducing complex dislocations interactions) and its effect on plastic deformation, massive numerical computation is necessary. Since 1990, simulation codes have been developed by French researchers. Among these codes, the code TRIDIS developed by the SIMAP laboratory in Grenoble is the pioneer dynamic dislocation code. In 2007, the project called NUMODIS had been set up as team collaboration between the SIMAP and the SRMA CEA Saclay in order to develop a new dynamics dislocation code using modern computer architecture and advanced numerical methods. The objective was to overcome the numerical and physical limits of the previous code TRIDIS. The version NUMODIS 1.0 came out in December 2009, which confirms the feasibility of the project. The project OPTIDIS is initiated when the code NUMODIS is mature enough to consider parallel computation. The objective of the project in to develop and validate the algorithms in order to optimize the numerical and performance efficiency of the NUMODIS code. We are aiming at developing a code able to tackle realistic material problems such as the interaction between dislocations and irradiation defects in a grain plastic deformation after irradiation. These kinds of studies where local mechanisms are correlated with macroscopic behavior is a key issue for nuclear industry in order to understand material aging under irradiation, and hence predict power plant secured service life. To carry out such studies, massive numerical optimizations of NUMODIS are required. They involve complex algorithms lying on advanced computational science methods. The project OPTIDIS will develop through joint collaborative studies involving researchers specialized in dynamics dislocations and in numerical methods. This project is divided in 8 tasks over 4 years. Two PhD thesis will be directly funded by the project. One will be dedicated to numerical development, validation of complex algorithms and comparison with the performance of existing dynamics dislocation codes. The objective of the second is to carry out large scale simulations to validate the performance of the numerical developments made in OPTIDIS . In both cases, these simulations will be compared with experimental data obtained by experimentalists.

Web Site : OptiDis

Title: New platform for parallel, hybrid quantum/classical simulations

Grant: ANR 2007 – CIS

Partners:CPMOH (Bordeaux, UMR 5098), DRIMM, IMPREM (leader of the project, Pau, UMR 5254), Institut Néel ( Grenoble, UPR2940)

Duration: 2008 – 2010

Overview: Physicists, chemists and computer scientists join forces in this project to further design high performance numerical simulation of materials, by developing and deploying a new platform for parallel, hybrid quantum/classical simulations. The platform synthesizes established functions and performances of two major European codes, SIESTA and DL-POLY, with new techniques for the calculation of the excited states of materials, and a graphical user interface allowing steering, visualization and analysis of running, complex, parallel computer simulations. The platform couples a novel, fast TDDFT (Time dependent density functional theory) route for calculating electronic spectra with electronic structure and molecular dynamics methods particularly well suited to simulation of the solid state and interfaces. The software will be capable of calculating the electronic spectra of localized excited states in solids and at interfaces. Applications of the platform include hybrid organic-inorganic materials for sustainable development, such as photovoltaic materials, bio- and environmental sensors, photocatalytic decontamination of indoor air and stable, non-toxic pigments.

Web Site: Nossi

Title: New platform for parallel, hybrid quantum/classical simulations

Grant: ANR MMSA - ARA MAsses de données

Partners: IRMA (Strasbourg, UMR 7001)), LSIIT (leader of the project, Strasbourg, UMR 7005)

Duration: 2005 – 2008

Overview: Numerical simulation is a continuously growing area, especially with the increasing computational power of current computer technology, thus covering larger and larger scientific application fields. But at these days, monitoring tools are still seriously lacking, since developers and users desire more and more to get faster and faster feedbacks of the simulation results. In this project, we are interested in large scale simulations dealing with complex data (multivariate and multidimensional). Our aim is to realize a plate-form / framework to couple parallel and distributed simulations, like in GRID'5000, with an interactive monitoring and visualization system. This plate-form will be validated on two types of large scale applications: plasma and crack propagation simulation using multiscale approaches. For these applications, the simulation codes are definitely very complex and need some highly efficient tools to represent the large amount of data, to redistribute the data using visualization and to control and validate the corresponding computation algorithms. Since results may be multivariate and multidimensional, they need also specific data exploration and visualization tools.

Web Site: MASSIM

HALOBAR - Dark matter and the dynamical evolution of barred galaxies

Title: Dark matter and the dynamical evolution of barred galaxies

Grant: ANR - Programme blanc

Partners: Laboratoire d'Astrophysique de Marseille (leader of the project) , Astroparticules et Cosmologie

Duration: 2007 – 2010

Overview: We want to study the secular evolution of barred galaxies in the presence of both a gaseous component and a live and responsive halo. Although considerable steps have been made in understanding the two influences independently, little, if anything, has been done about understanding their coupled effect and the outcome of the internal competition between angular momentum emitters and absorbers when all partners are active. This is partly due to the fact that, so far, understanding one of the two influences was already a sufficient challenge. It is also partly due to the fact that an all-round approach is necessary at this stage. Simulations should be more performing, necessitating deep knowledge of N-body and hydrodynamic codes, as well as of the ways to link them. The effects of the resonances need to be fully understood, necessitating expertise in analytical work on resonances, but also in orbital structure theory including periodic orbits as well as chaotic ones. Software for the analysis of the resonances and the study of the orbital structure in the simulations is necessary. Finally, links with observations need to be very tight, since they will be the only way to ensure that the solutions found are realistic and relevant to real galaxies, rather than abstract mathematical models.

Web Site: