Wing Kam Liu, Professor, Department of Mechanical Engineering, Northwestern University, 2145 Sheridan Road, Evanston, IL 60208-3111, USA Wing Kam Liu has been Professor at the Department of Mechanical Engineering at Northwestern University since 1988. He is also Director of the NSF Summer Institute on Nano Mechanics and Materials. His research interests here include concurrent and hierarchical bridging scale methods for computational mechanics, in particular nano-mechanics and materials, and multi-scale analysis. He is an experienced author, having authored/co-authored over 100 published articles and the book Meshfree Particle Methods (Springer-Verlag, 2004) with Shaofan Li. He is the US Editor of the International Journal of Applied Mathematics and Mechanics (Springer) and has also worked as a consultant to a number of international companies and organizations. Eduard G. Karpov, Department of Mechanical Engineering, Northwestern University, 2145 Sheridan Road, Evanston, IL 60208-3111, USA Harold S. Park, Department of Mechanical Engineering, Northwestern University, 2145 Sheridan Road, Evanston, IL 60208-3111, USA