Problems of mathematical modelling of nonlinear processes

We give two examples of successful investigations of real complex nonlinear problems by using the computer simulation. In the both cases we solved the process optimization problem by using the input control. The first example: simulation of processes in targets for laser thermonuclear fusion (a spherical denterium-tritium target is radiated by a laser. The other example is optimization of technology of laser-plasma metal treatment. An advantage of this technology is that metal in the nitrogen atmosphere is exposed to the reradiation of a plasma cloud formed near the metal surface rather than to the radiation of the laser itself. Plasma ions intensively infiltrate the surface layer of metal due to which it appreciably hardens. It is required to choose the treatment regime that would guard the metal against destruction by the laser radiation (as it occurs with metals directly exposed to the laser radiation).