Ongoing projects

DEEP-ER: Dynamic Exascale Entry Platform - Extended Reach
The DEEP-ER project aims at extending the Cluster-Booster Architecture that has been developed within the DEEP project with a highly scalable, efficient, easy-to-use parallel I/O system and resiliency mechanisms. A Prototype will be constructed leveraging advances in hardware components and integrate new storage technologies. They will be the basis to develop a highly scalable, efficient and user-friendly parallel I/O system tailored to HPC applications. Building on this I/O functionality a unified user-level checkpointing system with reduced overhead will be developed, exploiting multiple levels of storage. The DEEP programming model will be extended to introduce easy-to-use annotations to control checkpointing, and to combine automatic re-execution of failed tasks and recovery of long-running tasks from multi-level checkpoint. The requirements of HPC codes with regards to I/O and resiliency will guide the design of the DEEP-ER hardware and software components. Seven applications will be optimised for the DEEP-ER Prototype to demonstrate and validate the benefits of the DEEP-ER extensions to the Cluster-Booster Architecture.

DEEP-ER flyer at ISC'14
Contact: Stéphane Lanteri
TECSER: Novel high performance numerical solution techniques for RCS computations
Funding agency: Specific Support for Research Works and Innovation Defense (French National Research Agency ASTRID 20013 program)
Contact: Stéphane Lanteri

Past projects

KidPocket: Analysis of RF children exposure linked to the use of new networks or usages
The last 20 years have witnessed a growing role of wireless communications, taking now a central place in the human activity. Today the number of users of mobile phones is close to 4 billions worldwide. This tendency is strengthened by the growth of new wireless systems which also use electromagnetic waves. This progress comes along with questions about potential sanitary effects linked to EMF exposure. Laws have been established to limit the exposure, and recommendations for a safe usage have been provided. Nevertheless due to new usages the public concern is still important, in particular for children or pregnant women. It is therefore important to have studies and tools to answer these questions, to improve the public information and to take into account this concern during the design of new technologies or services. This need of tools to assess and manage the exposure is fundamental to develop an efficient radio link taking into account the efficiency, the environmental constraints, the prevention of the EMF risk as well as the acceptability. Large efforts have been performed during the last 10 years to assess the exposure. Several ANR projects have been dedicated to these questions, in particular to improve the SAR measurement and the methods to check the compliance of systems. Current usages are evolving and questions do not focus only on compliance but also on day to day level of body exposure (local, whole body) or exposure of specific organs. Today, taking advantage of improvements of computational capabilities, the SAR assessment can be carried out using simulations. Nevertheless such estimations are facing the limited number of existing 3D numerical human models (less than 15 for adults and less than 3 child body models) and the lack of tools allowing us to bend the models to create new realistic postures. Given the high variability of the morphology or of the location of the sources, the numerical calculation of SAR is facing also the lack of tools to manage the uncertainty. The objectives of the KidPocket project are to develop new child phantoms, to develop tools to deform phantoms in a consistent way with respect to the anatomy and create new posture in order to study the exposure linked to new usages. The objective is also to develop tools to manage the uncertainty attached to the exposure estimations.
Funding institution: ANR (programme VERSO 2009)
Project coordinator: Joe Wiart - Whist Laboratory (Wave Human Interactions and Telecommunications - Institut Télécom / Orange Labs)
Project-team contact: Stéphane Lanteri
Maxwell: Novel, ultra-wideband, bistatic, multipolarization, wide offset, microwave data acquisition, microwave imaging, and inversion for permittivity
This project aims at the development of a complete microwave imaging system, with a frequency bandwidth of 1.87 GHz, ranging from 130 MHz to 2 GHz, using unstructured mesh solvers of the time harmonic Maxwell equations which drive a generalized least-squares inversion engine, whose output is a subsurface map of the relative permittivity. Subsidiary goals of the project are: (a) the construction and calibration of two ultra-wideband antennas, (b) the construction of two types of carriages for performing data acquisition, (c) the acquisition of dense microwave data with very wide offset for the entire bandwidth from 130 MHz to 2 GHz and for 2 orthogonal co-polarizations and one cross-polarization, (d) the reprocessing of data, including gain and kinematic inversion using conventional seismic processing formulations and (e) the development of discontinuous Galerkin solvers on simplex meshes for the numerical resolution of the time harmonic Maxwell equations and their integration into an inversion system.
Funding institution: ANR (programme non-thématique, 2007)
Project coordinator: Christian Pichot - LEAT Laboratory (Electronics, Antennas and Telecommunications Laboratory)
Project-team contact: Stéphane Lanteri
DONUT: (Statistical numerical dosimetry)
In parallel to biological studies, it is required to assure that exposure of workers and general public to electromagnetic fields are below defined thresholds. Numerical computation allows to obtain accurate results, but it is dependent on the human morphology and the sharpness of the model. It appears judicious to obtain SAR values which are representative in terms of mean value and standard deviation for a given category of individuals. In this context, the objectives of the DONUT project are to develop and validate a new nuumerical dosimetry approach for dealing with the variability of the exposure, in order do directly deduce a statistical analysis of the effects of the exposure. The proposed numerical methodology which is based on a stochastic finite element method and can exploit in a non intrusive way existing Maxwell solvers for the calculation of the SAR in biological tissues. This feature is demonstrated in the project by considering both finite difference, finite element and discontinuous Galerkin Maxwell solvers.
Funding institution: Fondation Santé et Radiofréquences
Project coordinator: Damien Voyer - Ampère Laboratory
Project-team contact: Stéphane Lanteri
HOUPIC: High order finite element particle-in-cell solvers on unstructured grids
Particle-In-Cell (PIC) codes have become an essential tool for the numerical simulation of many physical phenomena involving charged particles, in particular beam physics, space and laboratory plasmas including fusion plasmas. Genuinely kinetic phenomena can be modeled by the Vlasov-Maxwell equations which are discretized by a PIC method coupled to a Maxwell field solver. Today’s and future massively parallel supercomputers allow to envision the simulation of realistic problems involving complex geometries and multiple scales. However, in order to achieve this efficiently new numerical methods need to be investigated. This includes the investigation of high order very accurate Maxwell solvers, the use of hybrid grids with several homogeneous zones having their own structured or unstructured mesh type and size, and a fine analysis of load balancing issues. To this aim this project proposes to develop and compare Finite Element Time Domain (FETD) solvers based on the one hand on high order Hcurl conforming elements and on the other hand on high order Discontinuous Galerkin (DG) finite elements and investigate their coupling to the particles.
Funding institution: ANR (programme CIS 2006 - Calcul Intensif et Simulation)
Project-team contact: Loula Fezoui
HeadExp: realistic numerical modeling of human head tissues exposure to electromagnetic waves emitted from mobile phones
The ever-rising diffusion of mobile phones has determined an increased concern for possible consequences of electromagnetic radiation on human health. In fact, when a cellular phone is in use, the transmitting antenna is placed very close to the user's head where a substantial part of the radiated power is absorbed. Biological effects of microwave radiation are investigated both from the experimental and numerical viewpoints. Concerning numerical modeling, the power absorption in a user head is computed using discretized models built from clinical MRI data. The great majority of such numerical studies are conducted using FDTD (Finite Difference Time Domain) methods where the cartesian computational mesh is directly deduced from the voxelized geometrical model. This project aimed at filling the gap between human head MRI images and accurate numerical modeling of electromagnetic waves propagation in the user's head tissues. This has been made possible by the development of appropriate image analysis tools and automated unstructured mesh generation tools for the construction of realistic discretized human head models. Then, numerical dosimetric studies are conducted using finite volume time-domain (FVTD) and discontinuous Galerkin time-domain (DGTD) methods designed on unstructured tetrahedral meshes.
Funding institution: INRIA (Cooperative Research Initiatives 2003-2004)
Project-team contact: Stéphane Lanteri
DiscoGrid: Distributed objects and components for high performance scientific computing on the Grid'5000 test-bed
This project aims at studying and promoting a new paradigm for programming non-embarrassingly parallel scientific computing applications on distributed, heterogeneous, computing platforms. The target applications require the numerical resolution of systems of partial differential equations modeling electromagnetic wave propagation and fluid flow problems. More importantly, the underlying numerical methods share the use of unstructured meshes and are based on well known finite element and finite volume formulations. The project concentrates its activities on numerical kernels and related issues that are indeed not specific to the particular applications considered but are instead of interest to a large variety of other application contexts. The emphasis is put on designing parallel numerical algorithms and programming simulation software that efficiently exploit a computational grid and more particularly, the Grid5000 test-bed. In particular, the project studies the applicability of modern distributed programming principles and methodologies for the development of high performance parallel simulation software.
Funding institution: ANR (programme CIGC 2005 - Calcul Intensif et Grille de Calcul)
Project-team contact: Stéphane Lanteri
QSHA: Quantitative Seismic Hazard Assessment
Scientific strategies for seismic hazard assessment are changing rapidly because more data are available for earthquakes of different sizes and for different seismic active zones and because computer power makes simulations for quantitative estimation or uncertainties analysis a relatively reasonable challenge. The activities of this project aim at (1) obtaining a more accurate description of crustal structures for extracting rheological parameters for wave propagation simulations, (2) improving the identification of earthquake sources and the quantification of their possible size, (3) improving the numerical simulation techniques for the modeling of waves emitted by earthquakes, (4) improving empirical and semi-empirical techniques based on observed data and, (5) deriving a quantitative estimation of ground motion. From the numerical modeling viewpoint, essentially all of the existing families of methods (boundary element method, finite difference method, finite volume method, spectral element method and discrete element method) will be extended for the purpose of the QSHA objectives.
Funding institution: ANR (programme CATTEL 2005 - Catastrophes Telluriques et Tsunami)
Project-team contact: Nathalie Glinsky