Proximal Stochastic Dual Coordinate Ascent
  We introduce a proximal version of dual coordinate ascent method. We demonstrate how the derived algorithmic framework can be used for numerous regularized loss minimization problems, including $\ell_1$ regularization and structured output SVM. The convergence rates we obtain match, and sometimes improve, state-of-the-art results. 
Shai Shalev-Shwartz and Tong Zhang
stat.ML cs.LG math.OC