“…For a survey of some techniques see, for example [Chen & Dong, 1993a, 1993b. The use of conventional, linear control actions to stabilize asymptotically a trajectory of a system in a chaotic regime has been analyzed for different types of nonlinear systems [Chen, 1993;Chen & Dong, 1992, 1993a, 1993b, 1993cChen et al, 1993;Hartley & Mossayebi, 1992;Ogorzalek, 1993;Vincent & Yu, 1991]. Some other nonconventional approaches for stabilizing equilibria or periodic orbits present in chaotic attractors have been developed [Alvarez, 1994a;Genesio et al, 1993;Hubinger et al, 1994;Vincent & Yu, 1991].…”