Identification and Control of Symmetric Systems
  In a recent paper [Phys. Rev. E 57, p. 1550 (1998)] we demonstrated that the symmetries of the evolution equation and the target state have a profound effect on the selection of the admissible control parameters. In the present paper we extend these results to the case of time-periodic target states and inexact symmetries. We also argue that the problem of phase space reconstruction is affected by the presence of symmetries similarly to the control problem. 
R. O. Grigoriev