Welcome to my research webpage. Please feel free to distribute the material as widely as possible. I am reachable via the following email address : romain.nguyenvanyen@gmail.com

Romain Nguyen van yen

Publications

Pereira, R. M., RNVY, Farge, M., Schneider K. Wavelet methods to eliminate resonances in the Galerkin-truncated Burgers and Euler equations Physical Review E 2013, vol. 87, 033017
RNVY, Fedorczak, N., Brochard, F., Bonhomme, F., Farge, M., Schneider, K., Monier-Garbet, P. Tomographic reconstruction of tokamak plasma light emission from single image using wavelet-vaguelette decomposition Nuclear Fusion 2012, vol. 52, 013005
RNVY, Farge, M. & Schneider, K. Scale-wise coherent vorticity extraction for conditional statistical modeling of homogeneous isotropic two-dimensional turbulence Physica D, 2012, Vol. 241, pp. 186-201
Farge, M., Schneider, K., Pannekoucke, O. & RNVY Multiscale representations: fractals, self-similar random processes and wavelets Harindra, J. F. (ed.), Handbook of Environmental Fluid Dynamics, CRC Press, 2012
RNVY, Farge, M. & Schneider, K. Energy Dissipating Structures Produced by Walls in Two-Dimensional Flows at Vanishing Viscosity Phys. Rev. Lett., American Physical Society, 2011, Vol. 106(18), pp. 184502
RNVY, Kadoch, B., Kumar, V., Ménétrier, B., Farge, M. & others Influence of waves on Lagrangian acceleration in two-dimensional turbulent flows ESAIM: Proceedings, 2011, Vol. 32, pp. 231-241
RNVY, Sonnendrücker, É., Schneider, K. & Farge, M. Particle-in-wavelets scheme for the 1D Vlasov-Poisson equations ESAIM: Proceedings, 2011, Vol. 32, pp. 134-148
Khujadze, G., RNVY, Schneider, K., Oberlack, M. & Farge, M. Coherent vorticity extraction in turbulent boundary layers using orthogonal wavelets Proceedings of the CTR Summer Program 2010
RNVY, del Castillo-Negrete, D., Schneider, K., Farge, M. & Chen, G. Wavelet based density estimation for noise reduction in plasma simulation using particles J. Comp. Phys., 2010, Vol. 229(8), pp. 2821-2839
RNVY, Farge, M. & Schneider, K. Wavelet regularization of a Fourier-Galerkin method for solving the 2D incompressible Euler equations ESAIM: Proceedings, 2009, Vol. 29, pp. 89-107
RNVY, Farge, M., Kolomenskiy, D., Schneider, K. & Kingsbury, N. Wavelets meet Burgulence: CVS-filtered Burgers equation Physica D, 2008, Vol. 237(14-17), pp. 2151-2155
E. Fischer-Friedrich, RNVY and K. Kruse Surface waves of Min-proteins Phys. Biol., 2007, Vol. 4, pp. 38-41

Unpublished documents

Posters

IUTAM Symposium on vortex dynamics (Fukuoka, 2013) : Production of dissipative vortices by solid bodies in incompressible fluid flows
European turbulence conference 13 (Warsaw, Sept. 2011) :
- Dissipation by two-dimensional flows at vanishing viscosity
- Remarks on boundary layers and energy dissipation in high Reynolds number 2D flows
Analysis and Computation of Incompressible Fluid Flow (IMA, Minneapolis, Feb. 2010) :
- Energy dissipation in the inviscid limit of a 2D dipole-wall collision
- Dissipative structures in the inviscid limit of 2D wall-bounded turbulence
Wavelets in Burgers land
Extraction of coherent structures out of Tore Supra density signals using wavelets
Wavelet based density estimation for noise reduction in plasma simulation using particles
TSFP 7 (Ottawa, July 2011) : Coherent Vorticity Extraction in Turbulent Boundary Layers Using Orthogonal Wavelets

Talks

Mathematical Theory of Turbulence workshop (Nagoya, Dec. 2012): Dissipation at high Reynolds number: a mystery not yet solved!
Berlin Mathematical School "What is..." seminar (Berlin, Nov. 2012): What is... a dissipative weak solution?
CNMAC Annual Meeting (Aguas de Lindoia, Sept. 2012): Tomographic reconstruction of light emission from tokamak plasmas using wavelet-vaguelette decomposition
Seminar of UFRJ department of mathematics (Rio de Janeiro, Sept. 2012): Nonstationnary boundary layers and energy dissipation in incompressible flows
European turbulence conference 13 (Warsaw, Sept. 2011): Coexistence of two dissipative mechanisms in two-dimensional turbulent flows
Festival de théorie (Aix-en-provence, July 2011): Dissipation by flows
Mathematics for ITER Colloquium (CIRM, Marseille): Wavelet based density estimation for noise reduction in plasma simulation using particles
PhD defense (ENS, Paris, Dec. 2010): Wavelet-based study of dissipation in plasma and fluid flows
GDR turbulence (ESPCI, Paris, Nov. 2010): Volume penalization at vanishing viscosity
Workshop on Immersed Boundary Methods (CIRM, Marseille, Sept. 2010): Energy dissipating structures in the vanishing viscosity limit of 2D incompressible flows with solid boundaries
CEMRACS Summer school (CIRM, Marseille, August 2010): Particle-in-Wavelet scheme for the 1D Vlasov-Poisson equations
Workshop TURB 2010 (MPIPKS, Dresden, May 2010): Tomographic reconstruction of Tore Supra edge plasma radiation by wavelet-vaguelette decomposition
Workshop on Euler and Navier-Stokes equations with boundaries(WiKo, Berlin, April 2010): Energy dissipating structures in the vanishing viscosity limit of 2D incompressible flows with solid boundaries
APS DFD Meeting (Minneapolis, 2009): Coherent enstrophy dissipation in the inviscid limit of 2D turbulence
Workshop on multiscale analysis (CIRM, Marseille, 2008) : Wavelets meet Burgulence: CVS-filtered Burgers equation
Mathematical image processing meeting (CIRM, Marseille, 2007) : Extraction of coherent structures out of 2D turbulent flows : comparison between real-valued orthogonal wavelet bases and complex valued wavelet frames

Theses

PhD thesis (2010) : Wavelet-based study of dissipation by flows in turbulent fluids and plasmas
M2 Master thesis (2007) : Généralisation de l'algorithme itératif [...]
M1 Master thesis (2005) : Le système Min chez Escherichia coli

Codes

Kicksey-Winsey C++ toolbox

Kicksey-Winsey (KW) is a C++ multi-purpose toolbox which associates wavelet analysis and fluid flow computations. It is available in open source under the GPL license, for more information, visit the Kicksey-Winsey homepage.

Matlab wavelet transform and filtering toolbox

This toolbox was developed by Jori Rupert-Felsot and myself and allows computations of graphical representations of Morlet wavelet transforms in 1D under Matlab.
More information is available on the toolbox's homepage.

Tomography

This software was developed to analyze movie frames taken by a fast camera installed in a tokamak, in the way described in the Nuclear Fusion paper listed above.
More information is available on the toolbox's homepage.

Multimedia

Movies of Navier-Stokes flows with randomized wavelet coefficients (10/2009)
Wavelet coefficients of solutions to the 1D Burgers equation.
Perturbation of single wavelet coefficients in Navier-Stokes flows (10/2009), some movies there.
Some old work on active penalization (in french, 10/2009).
Movie presented at the Fukuoka IUTAM symposium (see also the corresponding poster above).
Some results presented at ETC 12 in Marburg (in french):
Volume rendering of the particle distribution function during a two-stream instability in an electrostatic plasma (collaboration with Éric Sonnendrücker).
Movie showing a typical time evolution of the vorticity field for decaying 2D homogeneous isotropic turbulence.
Movie showing the vorticity field during a dipole wall collision computed using volume penalization.
Movie showing the stable behavior of the code when viscosity is set to zero, thanks to positivity-preserving mask smoothing.
Vortex merger computations: comparison between inviscid, viscous, DWT-filtered, DTCWT-filtered solutions (see ESAIM paper above).

Some useful external links

Librairies

HDF5 pour la gestion des jeux de données
The "Fastest Fourier transform in the West" (FFTW)
Portable Expression Template Engine (PETE) extrait de FreePOOMA
OpenMPI
Matlab Central
Boost C++ libraries
VTK et Mesa3d pour le rendu graphique (2D pour le moment)
Pour le calcul en précision arbitraire : la GNU Multiprecision Library

Outils de développement

GCC bien sûr. Version 4.3 pour le support d'openmp.
Projet Trac hébergé à l'IPSL
Plate forme Eclipse
éditeur UML et générateur de code Papyrus
L'environnement Matlab

Romain Nguyen van yen, May 2013