A note on the generalized min-sum set cover problem
  In this paper, we consider the generalized min-sum set cover problem, introduced by Azar, Gamzu, and Yin. Bansal, Gupta, and Krishnaswamy give a 485-approximation algorithm for the problem. We are able to alter their algorithm and analysis to obtain a 28-approximation algorithm, improving the performance guarantee by an order of magnitude. We use concepts from $\alpha$-point scheduling to obtain our improvements. 
Martin Skutella and David P. Williamson
cs.DS