Current PhD students

    Francesco Tucciarone is doing a PhD thesis under the co-supervision of Long Li and me. This PhD takes place within the ERC STUOD and focuses on the numerical simulation of stochastic realistic ocean models. These models are implemented within the NEMO code. The PhD defense is scheduled for march 2024.

    Benjamin Dufée did a PhD under the co-supervision of Dan Crisan (Imperial College) and myself within the ERC STUOD. His PhD proposed several efficient adaptations of ensemble Kalman filters to stochastic dynamics. The PhD will be defended the 29/09/2023. Benjamin will be contractual assistant professor (ATER) at the University of Southern Britany (Vannes).

    Berenger Hug is completing a PhD under the cosupervision of Arnaud Debussche and me on the mathematical analysis of stochastic Navier-Stokes equation. We have shown that the modelling under location uncertainty led to consistant large-scale representation of the Navier-Stokes equations in the sense that we demonstrated the existence of weak probabilistic solution in 3D (uniqueness of strong solution in 2D) and convergence toward the deterministic weak solutions in the limit of vanishing noise. We also shown recently that diffusion limits of the Navier-Stokes equation tends to the stochastic representation of Navier-Stokes equations under location uncertainty. Berenger is doing his PhD in parrallel of a full-time teaching in high school. The defense is planned for june 2024.

    Antoine Moneyron started his PhD in june 2023. He is cosupervised by Arnaud Debussche and me. His PhD focuses on the mathematical analysis of stochastic realistic ocean models in the following of both Berenger's PhD and Francesco's PhD.

Former students

    Elise Arnaud “Filtering methods from image sequences””

    In Elise’s thesis we have defined stochastic filters for the tracking of points from image sequences. We have in particular explored a family of systems called partial linear Gaussian models. These models rely on informative dynamics estimated from the image sequences and likelihood defined as a Gaussian mixture. The thesis has been defended in November 2004. Elise is now assistant professor (Maitre de Conférences) in Grenoble at the University Joseph Fourier. She is a member of the Inria group headed by Emmanuel Prados”

    Christophe Avenel "Stochastic level-sets for the tracking of closed curve".

    In this thesis we have proposed a stochastic level-set dynamics for the tracking of closed curves. Associated to a particle filter this approach has been applied for the tracking of convective cells, the detection and tracking of precipitation areas in weather watch radar, and the tracking of ice iso-density curves. This thesis has been defended in december 2011. Christophe at the moment on a post-doc position at University of Uppsala (Sweden).

    Ioana Barbu "3D motion estimation of turbulent fluids".

    This thesis funded through a DGA/INRIA grant focused on the estimation of 3D motion of particles transported by a turbulent fluid flow. In this work we considered a unified framework, in which a sparse constraint and a non negativity condition related to the particle density function have been considered. This study, associated to approached minimization procedures allows us to achieve a good balance between the affordable computation load and efficiency. The defense of this PhD, co-supervised with Cédric Herzet, has been defended the 15 of december 2014.

    Yacine Ben Ali, did a CIFRE PhD (2017-2020) within a collaboration with CSTB Nantes on the setting of a variational technique for wind engineering for high rise buildings. Yacine PhD, ``Investigating data-model coupling using adjoint techniques for wind engineering'', was cosupervised by Gilles Tissot, Dominic Heitz and myself. Yacine developed an original assimilation technique based on surface pressure measurement for the reconstruction of the 3D time-average flow.

    Sébastien Beyou "Estimation of sea surface currents from image sequences".

    In this thesis we studied the setting of efficient stochastic filtering techniques for image assimilation. The proposed particle filter relies on a proposal density built from Kalman filter mechanisms. This thesis has been defended in july 2013.

    Pranav Chandramouli , "Coarse eddies simulation and data assimilation for recontruction of wake flows".

    The thesis of Pranav takes place within a collaboration with Sylvain Laizet (Imperial College). In his thesis, we proposed coarse eddies simulations formulated though the location uncertainty principle. Such stochastic representation leads to large-scale flow representations amenable to efficient simulations. Data assimilation schemes to couple 2D plans of 3 components velocity fields are also investigated in this PhD thesis. This thesis is co-supervised with Dominique Heitz and Sylvain Laizet

    Thomas Corpetti “ Fluid motion analysis from image sequences”

    In this thesis we have studied motion estimators dedicated to image sequences of fluid flows. The motion estimator relies on a data model built from the integration along time of the continuity equation and on a second order div-curl regularization term. A method for characterizing motion fields in term of sink/ sources and vortices is also described. The thesis has been defended on July 2002. The thesis have been published as a book in hermes collection (in French). Thomas is senior researcher (DR) at the CNRS

    Anne Cuzol “Tracking and estimation of fluid motion velocity fields”

    During Anne’s thesis we have worked on the definition of low dimensional motion estimators for fluid motions. The motion is represented as a linear combination of adapted basis functions derived from so called vortex particles. The tracking of such representation is formulated through a stochastic filter. The thesis has been defended in December 2006. Anne holds now an assistant professor position (Maitre de Conférences) at the University of Bretagne Sud.

    Pierre Dérian "Wavelets and Fluid motion estimation".

    In the PhD thesis of Pierre Derian, we have proposed several computationally efficient motion estimator based on wavelet bases. High order and power law regularization were implemented on such bases. This thesis, has been defended in November 2012. Pierre is now on a Post-doctoral position at Chico University.

    Alejandro Gronskis.

    During Alejandro’s Post-doc (2009-2010), we proposed together with Dominique Heitz an optimal control technique for inlet boundary conditions in experimental fluid mechanics. The objective was to reproduce numerically a real world experimental flow behind an unknown obstacle. Alejandro Gronskis has been hired as a CONICET researcher after his post-doc at the University of Buenos Aires.

    Patrick Heas

    Patrick was on a research engineer position within the FET FLUID project from 2005 to 2007 and on a post-doc position at Cemagref Rennes from 2007b to 2008. We worked on the estimation of stratified atmospheric motions and on power law regularization functionals for motion estimation. Patrick is an Inria researcher since 2008. He is a member of the Aspi group.

    Pierre Hellier “Non linear registration of MRI acquisition of different subjects”

    In Pierre’s thesis, cosupervised with Christian Barillot, we have proposed an efficient and robust method for medical image registration. The method extends in 3D hierarchical motion estimators. The thesis has been defended in 2000. Pierre was Inria researcher from 2002 to 2011. He is now a researcher at technicolor.

    Souleyman Kadri

    During Souleyman’s Post-doc (2010-2012), we explored wavelets based motion estimator and large scales optimal control techniques. Souleyman is now assistant professor in Mathematics at the University of La Rochelle. We still work together on the mathematical analysis of uncertainty formulation of fluid flow dynamics.

    Mussaab Khalid

    completed his PhD with an Irstea grant from 2014 to 2017, in collaboration with the hydrology team at Inrae Lyon. The PhD, entitled (Analysis of water flows videos for surface velocity estimation) was co-supervised by Lionel Pi\'enard (INRAe) and me. It was centred both on the definition of an optical-flow estimator dedicated to river flow and the 3D reconstruction of the river surface. Mussaab is currently software Engineer in a private company.

    Long Li

    completed his PhD under my supervision between 2019 and 2021. His PhD entitled ``Stochastic modeling and numerical simulation of ocean dynamics '' focused on the derivation of stochastic ocean dynamics models in the framework of the modelling under location uncertainty. Since 2021, Long holds a Starting Research Position (SRP) at Inria within the ERC project STUOD.

    Lionel Oisel “3D dense reconstruction of complex scenes”

    In Lionel’s thesis, co-supervised with Luce Morin, we have proposed a matching technique for the estimation of dense disparity maps. This thesis has been defended in November 1998. Lionel is now research manager at technicolor, where he leads a group of 30 peoples on multimedia analysis for the improvement of the content production workflow.

    Benoît Pinier, "Similarity models and uncertainty models for ocean atmosphere coupled models".

    In this thesis, granted by the IRMAR laboratory and co-supervised with R. Lewandovsky (IRMAR), we studied new formulations of ocean atmosphere coupled models. The idea is here to assess the use of turbulence models based on similarity models and to derive new representations under uncertainty models for such coupled models.

    Nicolas Papadakis “Variational techniques for the racking of curves and motion fields”

    The aim of Nicolas’s thesis consisted in studying variational techniques defined from data assimilation principles for the tracking of curves and motion fields. The technique has been also extended to the estimation of low order dynamical systems. The thesis has been defended in November of 2007. Nicolas is a CNRS Researcher at the Institut de Mathématiques de Bordeaux.

    Christoph Papin “Tracking and characterization of convective cells”

    In the thesis of Christophe, we investigated the tracking of convective clouds systems through level-sets. This thesis co-supervised with Patrick Bouthemy has been defended in December 1999. Christophe is researcher at Kodak

    Valentin Resseguier , " Oceanic models under uncertainty and image assimilation".

    Valentin defended is PhD in January 2017. I was granted through an Ifremer/Inria grant and was co-supervised by B. Chapron and myself. His subject of study concerns the definition of stochastic dynamics models for the upper oceanic streams. We intend to use high resolution satellite images to calibrate the parameters of the corresponding dynamics under uncertainty.

    Cordelia Robinson , "Image assimilation for the numerical recontruction of wake flows".

    In the thesis of Cordelia, we proposed a variational assimilation technique allowing the reconstruct the complete 3d flow behind an unknown obstacle. To that purpose we relied on 3D velocity measurements captured within several 2D sheets. These observation are coupled within a data assimilation framework with an accurate Navier Stokes solver. This thesis was co-supervised with Dominique Heitz

    Romain Schuster, Romain did a PhD on CIFRE Grant with the company ITGA. His PhD, ``Development of an image-based measurement method to characterize large scale indoor airflows'', was cosupervised by me and Dominique Heitz. He worked on the setting of an optical flow estimator for flow analysis in hood extractor. Romain is Research Engineer in the ITGA company.

    Yin Yang "Variational ensemble methods for image assimilation".

    Yin thesis is centered on the study of new optimal control strategies formulated through an ensemble of forecast trajectories. This technique is computationally efficient and avoids the computation of the adjoint dynamics required in the traditional variational techniques. The problem is defined in a reduced subspace spanned by the different samples and introduces a time varying covariance error model. The defense has been defended the 16 of december 2014.