Xj. Li et Ks. Liu, THE EFFECT OF SMALL TIME DELAYS IN THE FEEDBACKS ON BOUNDARY STABILIZATION, Science in China. Series A, Mathematics, Physics, Astronomy & Technological Sciences, 36(12), 1993, pp. 1435-1443
In this paper we discuss the effect of small time delays in the feedba
cks on stabilization. It is proved that with respect to small time del
ays in the feedbacks, (boundary) stabilizations of parabolic systems a
re robust, but symmetric stabilization of infinitely-dimensional conse
rvative systems is not robust. For example, the current boundary stabi
lization of the wave equation is not robust with respect to small time
delays in its feedback. This is an answer to a problem posed in [1].