1. Macquarie University,School of Computing,Sydney,Australia
2. University of Wollongong,School of Computing and Information Technology,Wollongong,Australia
3. Academy of Mathematics and Systems Science, Chinese Academy of Sciences,Beijing,China
4. Beihang University,Beijing Advanced Innovation Center for Big Data and Brain Computing,Beijing,China
5. IBM T. J. Watson Research Center,Yorktown,NY,USA