wlrush@water.waterloo.edu (Wenchantress Wench Wendall) (10/27/89)
DEPARTMENT OF COMPUTER SCIENCE UNIVERSITY OF WATERLOO SCIENTIFIC COMPUTATIONS SEMINAR ACTIVITIES -Thursday, November 2, 1989 Professor John Carminati, Murdoch University, Australia, will speak on ``New Tools for Old Problems.'' TIME: 3:30 p.m. ROOM: DC 1304 ABSTRACT The application of the MAPLE system to some classical and fascinating problems in differential geometry and other important topics will be presented. October 26, 1989
wlrush@water.waterloo.edu (Wenchantress Wench Wendall) (11/09/89)
& Inst. for Adv. Comp. Studies will speak on... DEPARTMENT OF COMPUTER SCIENCE UNIVERSITY OF WATERLOO SEMINAR ACTIVITIES SCIENTIFIC COMPUTATIONS SEMINAR -Thursday, November 16, 1989 Professor Howard C. Elman, Dept. of Computer Science and Institute for Advanced Computer Studies, University of Maryland, will speak on ``Iterative Methods for Cyclically Reduced Non-Self-Adjoint Linear Systems.'' TIME: 3:30 p.m. ROOM: DC 1304 ABSTRACT We study iterative methods for solving linear systems of the type arising from two-cyclic discretizations of non-self-adjoint two-dimensional elliptic partial differential equations. A prototype is the convection-diffusion equation. The methods consist of applying one step of cyclic reduction, resulting in a ``reduced system'' of half the order of the original discrete problem, combined with a block iterative technique for solving the reduced system. For constant coefficient problems, we present analytic bounds on the spectral radii of the iteration matrices in terms of cell Reynolds numbers that show the methods to be rapidly convergent. In addition, we describe numerical experiments that supplement the analysis and that indicate that the methods compare favourably with methods for solving the ``unreduced'' system. This work is joint with Gene Golub of Stanford University. November 6, 1989