1. a Department of Mechanical Engineering, Virginia Polytechnic Institute and State University, IALR, 150 Slayton Avenue, Danville, VA 24543, USA
2. b Department of Mechanical Engineering, Virginia Polytechnic Institute and State University, IALR, 150 Slayton Avenue, Danville, VA 24543, USA;, Email: linchi@vt.edu
3. c National ICT Australia, Australian Technology Park, Level 5, 13 Garden Street, Eveleigh, NSW 2015, Australia
4. d Intelligent System Division, National Institute of Standards and Technology, Gaithersburg, MD 20899, USA