Журнал прикладной и вычислительной математики

The main objective of this work is to evaluate the performance of RRE in reducing the discretization error when associated with ten types of CFD numerical schemes of first, second and third orders of accuracy. The onedimensional advection-diffusion equation is solved with the finite volume method, for five values of the Peclet number (Pe), with uniform grids of 5 to 23,914,845 volumes, allowing for up to 14 RRE. Results are obtained for temperature at the center of the domain, average of the temperature field, and heat transfer rate. It was found that: (1) RRE is extremely effective in reducing the discretization error for all the variables, numerical schemes and Pe, reaching an order of accuracy of up to 18.9; and (2) The second-order central difference scheme together with RRE is the one that presents the smallest error for the dependent variable.

The work addresses a stochastic Lotka-Volterra system with delays of neutral type for which global asymptotic stability criteria are established.

In this paper, we define a new unifom t-(v, k, λ)n design on n-dimension. We illustrate with examples this design for n=2 and n=3. For n=1, we show that this is a t-(v, k, λ) design. We consider the cases of symmetric and Steiner system of uniform t-(v, k, λ)n design.