Comments on "Perturbation bounds for root-clustering of linear systems in a specified second order subregion"

This paper comments on the results of the above mentioned paper by Bakker-Luo-Johnson (ibid. vol.40 (1995)). We note that Theorems 3.1 and 4.1 are incorrectly stated, i.e., they are not valid for the non-/spl Omega/-transformable regions. The results cannot cover the ride quality region listed in Table 1 since it is a non-/spl Omega/-transformable region.