UNIFORMLY HIGHER ORDER ACCURATE EXTRAPOLATIONS TO SOLUTIONS OF UNIFORMLY CONVERGENT DISCRETIZATION METHODS FOR SINGULARLY PERTURBED PROBLEMS

We discuss the uniformly higher order accurate extrapolations,which are based on theuniform expansion for global error,to solutions of uniformly convergent discretizationmethods for singularly perturbed problems.By applying the approach to the Il’in-Allen-Southwell scheme for a non-self-adjoint problem,we obtain an extrapolation solution whichis uniformly convergent with order two.We confirm the result by numerical calculations.     

A class of incompletely exponentially fitted difference schemes for a singular perturbation problem

Some sufficient conditions are considered, under which the solutions of a class of incompletely exponentially fitted difference schemes converge uniformly in e, with orders one and two, to the solution of the singular perturbation problem: eu"+a(x)u’-b(x)u=f(x), for 0a>0, b(x)≥0. From these conditions.an incompletely exponentially fitted second-order scheme is derived. Finally, the results of some numerical experiments are given.     

奇异摄动问题的一类非完全指数拟合差分格式

本文分析奇异摄动问题εu"+a(x)u'-b(x)u=f(x),0a>0,b(x)≥0的一类非完全指数拟合差分格式一致收敛阶的充分条件,由此构造出二阶一致收敛的非完全指数拟合差分格式,最后给出数值结果.     

奇异摄动问题的一致收敛离散方法解的一致高阶精度外推

本文讨论基于整体误差一致展开式的一致收敛离散方法解的一致高阶精度外推.将该方法应用于非自共轭问题的Il'in-Allen-Southwell格式,我们得到了二阶一致收敛的外推解,并用数值计算说明该结论.     

Uniformly higher order accurate extrapolations to solutions of uniformly convergent discretization methods for singularly perturbed problems

We discuss the uniformly higher order accurate extrapolations, which are based on the uniform expansion for global error, to solutions of uniformly convergent discretization methods for singularly perturbed problems. By applying the approach to the Il'in-Allen-Southwell scheme for a non-self-adjoint problem, we obtain an extrapolation solution which is uniformly convergent with order two. We confirm the result by numerical calculations.Supported by the National Natural Science Foundation of China.