[ont.events] SCIENTIFIC COMPUTATIONS SEMINAR

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