Tongxi Yu is Professor Emeritus in the Department of Mechanical and Aerospace Engineering and University Honorary Fellow at The Hong Kong University of Science and Technology, Hong Kong, China. He received his PhD from Cambridge University, UK. He was professor at Peking University and UMIST (now University of Manchester) before moved to Hong Kong. He is a Fellow of ASME, the IMechE and HKIE, as well as an honorary member of the International Association of Impact Engineering. He is an overseas fellow of Churchill College, Cambridge, and a recipient of a Doctor of Science (DSc) from Cambridge University as well as a recipient of a China Higher Education Science and Technology Award (1st Class). Pu Xue is Professor in the School of Aeronautics at Northwestern Polytechnical University, China. She received her PhD from the Department of Mechanical and Aerospace Engineering, at The Hong Kong University of Science and Technology. She was also a Postdoctoral Fellow at the Hong Kong Polytechnic University, as well as at Northwestern University, USA.