1. College of Computer Science and Technology, Jilin University, Key Laboratory of Symbol Computation and Knowledge Engineering of Ministry of Education, Changchun 130012, P. R. China 2. Institute of High Performance Computing, Singapore 117528, Singapore 3. Department of Mechanical Engineering, National University of Singapore, Singapore 117576, Singapore 4. Institute of Electric and Information Engineering, Beihua University, Jilin 132021, P. R. China