  Recently, Bai and Benzi proposed a class of regularized Hermitian and
skew-Hermitian splitting methods (RHSS) iteration methods for solving the
nonsingular saddle point problem. In this paper, we apply this method to solve
the singular saddle point problem from the Stokes equations. In the process of
the semi-convergence analysis, we get that the RHSS method and the HSS method
are unconditionally semi-convergent, which weaken the previous results. Then
some spectral properties of the corresponding preconditioned matrix and a class
of improved preconditioned matrix are analyzed. Finally, some numerical
experiments on linear systems arising from the discretization of the Stokes
equations are presented to illustrate the feasibility and effectiveness of this
method and preconditioners.
