ALIASING AND TWO-DIMENSIONAL WELL-BALANCED FOR DRIFT-DIFFUSION EQUATIONS ON SQUARE GRIDS

A notion of "2D well-balanced" for drift-diffusion is proposed. Exactness at steady-state, typical in 1D, is weakened by aliasing errors when deriving "truly 2D" numerical fluxes from local Green's function. A main ingredient for proving that such a property holds is the optimality of the trapezoidal rule for periodic functions. In accordance with practical evidence, a "Bessel scheme" previously introduced in [SIAM J. Numer. Anal. 56 (2018), pp. 2845-2870] is shown to be "2D well-balanced" (along with former algorithms known as "discrete weighted means" or "tailored schemes".

Discrete Eulerian model for population genetics and dynamics under flow

Marine species reproduce and compete while being advected by turbulent flows. It is largely unknown, both theoretically and experimentally, how population dynamics and genetics are changed by the presence of fluid flows. Discrete agent-based simulations in continuous space allow for accurate treatment of advection and number fluctuations, but can be computationally expensive for even modest organism densities. In this report, we propose an algorithm to overcome some of these challenges. We first provide a thorough validation of the algorithm in one and two dimensions without flow.

Mathematical Modeling of Intracellular ATP Concentration in Vascular Endothelial Cells on Line Patterns

The migration of endothelial cells (ECs) is critical for various processes including vascular wound healing, tumor angiogenesis, and the development of viable endovascular implants. EC migration is regulated by intracellular ATP and recent observations in our laboratory on ECs cultured on line patterns - surfaces where cellular adhesion is limited to 15 m-wide lines that physically confine the cells - have demonstrated very different migration behavior from cells on control unpatterned surfaces.

A regularization model for stereo vision with controlled continuity

The problem of the computation of stereo disparity is approaehed as a mathematically ill-posed problem by using regularization theory. A controlled continuity constraint which provides a local spatial control over the smoothness of the solution enables the problem to be regularized while preserving the disparity discontinuities. The discontinuities are localized during the regularization process by examining the size of the disparity gradient at the gray value edges.

Computing the eigenvectors of nonsymmetric tridiagonal matrices

The computation of the eigenvalue decomposition of matrices is one of the most investigated problems in numerical linear algebra. In particular, real nonsymmetric tridiagonal eigenvalue problems arise in a variety of applications. In this paper the problem of computing an eigenvector corresponding to a known eigenvalue of a real nonsymmetric tridiagonal matrix is considered, developing an algorithm that combines part of a QR sweep and part of a QL sweep, both with the shift equal to the known eigenvalue. The numerical tests show the reliability of the proposed method.

Death is not for me. Funerary contexts of warrior-chiefs from preroman Apulia

The discoveries of the last thirty years in Apulia have highlighted the leading role of this region, and especially ancient Peucetia, in the evolution of Lucanian and Apulian red-figured pottery. In fact, from the last decades of the fifth century BC onwards the aristocratic classes of Apulia (in the fourth century also those of the Daunian district) were the main patrons and consumers of the products of Italic workshops. As the most complex elements of the funerary assemblage there was a specific demand for those objects.