Continuum mechanical models have been used to regularize ill-posed problems in many applications in medical imaging analysis such as image registration and left ventricular motion estimation. In this work, we present a significant extension to the common elastic model which we call the active elastic model. The active elastic model is designed to reduce bias in deformation estimation and to all...

This article deals with the optimal transfer of a satellite between Keplerian orbits using low propulsion. It is based on preliminary results of Geffroy [Généralisation des techniques de moyennation en contrôle optimal, application aux problèmes de rendez-vous orbitaux à poussée faible, Ph.D. Thesis, Institut National Polytechnique de Toulouse, France, Octobre 1997] where the optimal trajectori...

Automatic and semi-automatic magnetic resonance angiography (MRA) segmentation techniques can potentially save radiologists large amounts of time required for manual segmentation and can facilitate further data analysis. Our proposed MRA segmentation method uses a mathematical modeling technique which is well-suited to the complicated curve-like structure of blood vessels. Specifically, we defi...

A unified approach based on convex optimization is proposed for finding equilibrium configurations of structures consisting of no-tension or no-compression isotropic material in small strain and deformation. The semidefinite programming (SDP) problem is formulated so as to give the same optimizer as that of the minimization problem of total potential energy. An equilibrium configuration is obta...

This paper presents an application of a flexible model-based template matching algorithm named "deformable template matching." The template which models the shape of objects consists of some nodal points and segments that connect the nodal points sequentially. The template holds information about the known deformation of the object's shape, and it makes the shape recognition flexible. The match...

The Topological Active Netmodel for image segmentation is a deformable model that integrates features of region–based and boundary– based segmentation techniques. The segmentation process turns into a minimization task of the energy functions which control the model deformation. We used Differential Evolution as an alternative evolutionary method that minimizes the decisions of the designer wit...

A geometric approach for 3D object segmentation and representation is presented. The segmentation is obtained by deformable surfaces moving towards the objects to be detected in the 3D image. The model is based on curvature motion and the computation of surfaces with minimal areas, better known as minimal surfaces. The space where the surfaces are computed is induced from the 3D image (volumetr...

In this article, we study minimization of the energy of a Landau-de Gennes liquid crystal elastomer. The total energy consists of the sum of the Lagrangian elastic stored energy function of the elastomer and the Eulerian Landau-de Gennes energy of the liquid crystal. There are two related sources of anisotropy in the model, that of the rigid units represented by the traceless nematic order tens...