gain an insight into the calculus of variations and to apply the methods to complicated problems of concern.
Hence, the current book is not only an ideal textbook for graduate students and
undergraduate students of senior grade, but also a monograph for researchers in
various fields. I am sure that the book will expose the achievements of my two
colleagues to the international community of applied mathematics and promote the
academic exchanges.
March 2016
Dr. Haiyan Hu
President and Professor of Applied Mechanics
Beijing Institute of Technology
Beijing, China
vi
Foreword