The goal of the proposed framework is to ensure that the refined labels of unlabeled nodes are consistent with their strongly connected nodes, as well as not too far away from their initial labels.
the above optimization problem can be solved directly since Q(Y) is convex (Zhu et al., 2003;Zhou et al., 2004  a closed form solution can be derived as Y * u = (D uu + µI uu − W uu ) −1 (W ul Y l + µY 0 u ).