K.F. Ng
Department of Mathematics
Chinese University of Hong Kong
Shatin, Hong Kong
E-mail:ngkf@cuhk.hk
Fax: (852)(2)603-5154
Tel: (852)(2)609-7968
N.C. Wong
Department of Applied Mathematics
Sun Yat-Sen University
Kaohsiung 80424, Taiwan, R.O.C.
E-mail:wong@math.nsysu.ed.tw
FAX: (886) (7) -551-2814
Tel: (886)(7)-531-9479