a mathematical model is presented in the present study to control‎ ‎the light propagation in an inhomogeneous media‎. ‎the method is ‎based on the identification of the optimal materials distribution‎ ‎in the media such that the trajectories of light rays follow the‎ ‎desired path‎. ‎the problem is formulated as a distributed parameter ‎identification problem and it is solved by a numerical met...

The usual geometrical-optics expansion of the solution for the Helmholtz equation of a point source in an inhomogeneous medium yields two equations: an eikonal equation for the traveltime function, and a transport equation for the amplitude function. However, two difficulties arise immediately: one is how to initialize the amplitude at the point source as the wavefield is singular there; the ot...

The paper is devoted to the modelling of the propagation of acoustic waves at high frequency in anisotropic media. In this case, the WKB approximation results in eikonal equations whose Hamiltonians are neither convex nor concave in the impulse variable so that the Fermat principle fails. In this paper, methods of differential games are adopted for the analysis of wave propagation. If the Hamil...

We establish a definition of arrival time of a wavefront for a propagating wave in anisotropic media that is initially at rest and where the governing partial differential equation is the anisotropic wave equation. This definition of arrival time is not the same as the one in [8, 12]; it eliminates pathological discontinuities that can occur with the older definition and is still consistent wit...

An important question about a ne skeletons is the existence of di erential equations that are related to the A ne Distance and the Area Distance (hence to a ne skeletons) in the same way the Eikonal equation is related to the Euclidean Distance (and the medial axis). We show a surprisingly simple nonlinear second order PDE of Monge-Ampère type that relates to the a ne skeletons (and extends the...

In this paper, we present efficient and simple image segmentations based on the solution of two separate Eikonal equations, each originating from a different region. Distance functions from the interior and exterior regions are computed, and final segmentation labels are determined by a competition criterion between the distance functions. We also consider applying a diffusion partial different...

The geometric optics approximation to high frequency anisotropic wave propagation reduces the anisotropic wave equation to a static Hamilton–Jacobi equation. This equation is known as the anisotropic eikonal equation and has three different coupled wave modes as solutions. We introduce here a level set-based Eulerian approach that captures all three of these wave propagations. In particular, ou...

A novel spectral-element approach for the eikonal equation is presented based on the work of Tucker et al. This approach is readily implemented in standard finiteelement flow solvers developed for the Navier-Stokes equations. Results are presented for distance function (level set) for three planar configurations: circular cylinder, NACA 0012 airfoil, and T106 airfoil. Results demonstrate that t...

A new class of non-linear O(3) models is introduced. It is shown that these systems lead to integrable submodels if an additional integrability condition (so called the generalized eikonal equation) is imposed. In the case of particular members of the family of the models the exact solutions describing toroidal solitons with a non-trivial value of the Hopf index are obtained. Moreover, the gene...

In this paper we propose an adaptation of the static eikonal equation over weighted graphs of arbitrary structure using a framework of discrete operators. Based on this formulation, we provide explicit solutions for the L1,L2 and L∞ norms. Efficient algorithms to compute the explicit solution of the eikonal equation on graphs are also described. We then present several applications of our metho...