The regularity and exponential decay of solution for a linear wave   equation associated with two-point boundary conditions
  This paper is concerned with the existence and the regularity of global solutions to the linear wave equation associated with two-point type boundary conditions. We also investigate the decay properties of the global solutions to this problem by the construction of a suitable Lyapunov functional. 
Le Xuan Truong, Le Thi Phuong Ngoc, Alain Pham Ngoc Dinh (MAPMO),   Nguyen Thanh Long (UNS-HCMC)