Andrianov, Serge - In: Mathematics and Computers in Simulation (MATCOM) 57 (2001) 3, pp. 147-153
This report presents a method of constructing approximate symmetries and invariants in dynamical systems. At first, a similar approach was developed for linear systems (for example, the time-dependent invariants by Leach and Lewis). Beam line systems are considered as an example of such...