By training and by conviction I am an applied mathematician-computer scientist in the proper sense of the terms: I study the theory, the mathematical modeling and the optimization algorithms with the constant concern of their applications to complex industrial systems. This approach favors my collaborations with different areas of applied sciences. Being at the heart of my innovative research activities, DC programming and DCA, the sole efficient theoretical and algorithmic tools in nonconvex smooth/nonsmooth optimization and global optimization from the French school, intensively developed by Pham Dinh Tao and myself since 1994, are now become classic and increasingly popularized by researchers and practitioners worldwide.