1. Coordinated Science Laboratory and the Department of Mechanical Science and Engineering, University of Illinois Urbana-Champaign, Champaign, IL, USA
2. Department of Mechanical Engineering, University of Nevada, Reno, NV, USA
3. Coordinated Science Laboratory and the Department of Industrial and Enterprise Systems Engineering, University of Illinois Urbana-Champaign, Champaign, IL, USA
4. School of Computer Science, University of Science and Technology of China, Hefei, China