In this paper, a coupled radiative transfer equation and diffusion approximation model is extended for light propagation in turbid medium with low-scattering and non-scattering regions. The light propagation is modelled with the radiative transfer equation in sub-domains in which the assumptions of the diffusion approximation are not valid. The diffusion approximation is used elsewhere in the d...

The aim of this article is to shows that hierarchical matrices (H-matrices) provide a means to efficiently precondition linear systems arising from the streamline diffusion finite-element method applied to convection-dominated problems. Approximate inverses and approximate LU decompositions can be computed with logarithmic-linear complexity in the standard Hmatrix format. Neither the complexity...

Diffusion magnetic resonance imaging (dMRI) and tractography provide means to study the anatomical structures within the white matter of the brain. When studying tractography data across subjects, it is usually necessary to align, i.e. to register, tractographies together. This registration step is most often performed by applying the transformation resulting from the registration of other volu...

We evaluate a parallel Schur preconditioner for large systems of equations arising from a finite element discretization of the Navier-Stokes equations with streamline diffusion. The performance of the method is assessed on a biomedical problem involving oscillatory flow in a human abdominal bifurcation. Fast access to flow conditions in this location might support physicians in quicker decision...

introduction : due to the importance of laser light penetration and propagation in biological tissues, many researchers have proposed several numerical methods such as monte carlo, finite element and green function methods. among them, the monte carlo method is an accurate method which can be applied for different tissues. however, because of its statistical nature, monte carlo simulation requi...

— We prove error estimâtes for the streamline diffusion and the discontinuous Galerkin finite element methods for discretization of the Vlasov-Poisson équation. Résumé. — Nous démontrons des estimations d'erreur pour la méthode de Galerkin discontinue pour la discrétisation de l'équation de Vlasov-Poisson.

For the visualization of diffusion tensor imaging data, different approaches have been presented such as scalar metrics, glyphs or streamlines. Thereby, streamline techniques commonly referred to as fiber tracking provide a comprehensive and intuitive representation. For this reason, they are preferably applied for preoperative planning. The visualization of streamlines is solved by rendering l...

The dependence of the computation of advective-diffusive transport phenomena on the orientation of the mesh with respect to the flow direction is analyzed. Poor performance of the classical Galerkin finite element method in the convectiondominated regime is alleviated by stabilization. We propose definitions of the stability parameter that rationally incorporate the flow direction. Numerical te...