Iterative methods for linear systems;
Finite element methods for PDEs;
Domain decomposition; Multigrid methods.

An error estimate for two-dimensional Stokes driven cavity flow. by Z. Cai and Y. Wang, Math. Comp. 78 (771-787), 2009.
A multigrid method for the pseudostress formulation of Stokes problems by Z. Cai and Y. Wang, SIAM J. Sci. Comp, 29 (2078-2095), 2007.
A multigrid preconditioner for the mixed formulation of linear plane elasticity by J.E. Pasciak and Y. Wang, SIAM J. Numer. Anal., 44(478-493), 2006.
Overlapping Schwarz preconditioner for the mixed formulation of plane elascticity Appl. Numer. Math. 54(292-309), 2005.
Preconditioning for the mixed formulation of linear plane elasticity Dissertation, 2004.
Cascadic multigrid methods for motar Wilson finite element methods on planar linear elasticity. by W. Chen and Y.Wang, Numer. Math. J. Chinese Univ., 12(1-15), 2003.
Numerical Analysis of nonstationary convection-dominated convection-diffusion problems. by H. Cai, L. Wang and Y. Wang, J. Fudan Univ. Nat. Sci., 39(344-350), 2000.