@inproceedings{Yangcolt12,
  author    ={Chao-Kai Chiang and Tianbao Yang and Chia-Jung Lee and Mehrdad Mahdavi  and Chi-Jen Lu and   Rong Jin and Shenghuo Zhu},
  title     = {Online Optimization with Gradual Variations},
  booktitle = {COLT},
  year      = {2012},
  pages     = {-}
  }