부산대학교 도서관

We consider a Urysohn integral operator K with the kernel of the type of Green's function. For r ≥ 1 , a space of piecewise polynomials of degree ≤ r − 1 with respect to a uniform partition is chosen to be the approximating space, and the projection is chosen to be the orthogonal projection. The iterated Galerkin method is applied to the integral equation x − K (x) = f. It is known that the order of convergence of the iterated Galerkin solution is r + 2 and is 2 r at the partition points. We obtain an asymptotic expansion of the iterated Galerkin solution at the partition points of the above Urysohn integral equation. Richardson extrapolation is used to improve the order of convergence. A numerical example is considered to illustrate our theoretical results. [ABSTRACT FROM AUTHOR]