WAVELETS IN OPTIMIZATION AND APPROXIMATIONS

We give the explicit time description of the following problems: dynam ics of storage rings, optimal dynamics for some important electromecha nical system, Galerkin approximation for beam oscillations in liquid, computations of Melnikov functions for perturbed Hamiltonian systems. All these problems are reduced to the problem of the solving of the sy stems of differential equations with polynomial nonlinearities with or without some constraints. The first main part of our construction is some variational approach to this problem, which reduces initial probl em to the problem of the solution of functional equations at the first stage and some algebraical problems at the second stage. We consider also two private cases of our general construction. In the first case (particular), we have the solution as a series on shifted Legendre pol ynomials, which is parameterized by the solution of reduced algebraica l system of equations. In the second case (general), we have the solut ion in a compactly supported wavelet basis. Multiresolution expansion is the second main part of our construction. The solution is parameter ized by solutions of two reduced algebraical problems, the first one i s the same as in the first case and the second one is some linear prob lem, which is obtained from one of the next wavelet constructions. (C) 1998 IMACS/Elsevier Science B.V.