In a recent paper [7] the author considered the family of parametrized Thue equations

Convection-diffusion problem are the base for continuum mechanics. The main features of these problems are associated with an indefinite operator the problem. In this work we construct unconditionally stable scheme for non-stationary convection-diffusion equations, which are based on use of new variables. Also, we consider these equations in the form of convection-diffusion-reaction and constru...

The external environment of an organization is characterized by significant changes that occur in the social, economical, political and technological fields. The organization should know this setting and act effectively. A major challenge is how to define significant information in its diverse contexts. In a business process scenario, context could be defined as the minimum set of variables con...

This paper analyzes a number of high-order and optimized finite-difference methods for numerically simulating the propagation and scattering of linear waves, such as electromagnetic, acoustic, and elastic waves. The spatial operators analyzed include compact schemes, noncompact schemes, schemes on staggered grids, and schemes which are optimized to produce specific characteristics. The time-mar...

The numerical solution for a class of sub-diffusion equations involving a parameter in the range −1 < α < 0 is studied. For the time discretization, we use an implicit finite-difference Crank–Nicolson method and show that the error is of order k2+α , where k denotes the maximum time step. A nonuniform time step is employed to compensate for the singular behaviour of the exact solution at t = 0....

In this paper we present a high-order accurate cell-centered finite volume method for the semi-implicit discretization of multidimensional hyperbolic systems in conservative form on unstructured grids. This method is based on a special splitting of the physical flux function into a convective and a non-convective part. The convective contribution to the global flux is treated implicitly by mimi...

Based on the concept of alternating group and domain decomposition, we present a class of alternating group explicit-implicit method and an alternating group Crank-Nicolson method for solving convection-diffusion equation. Both of the two methods are effective in convection dominant cases. The concept of the construction of the methods is also be applied to 2D convection-diffusion equations. Nu...

High-order accurate finite difference schemes are derived for a nonlinear soliton model of nerve signal propagation in axons. Two types of well-posed boundary conditions are analysed. The boundary closures are based on the summation-by-parts (SBP) framework and the boundary conditions are imposed using a penalty (SAT) technique, to guarantee linear stability. The resulting SBP-SAT approximation...