Addenda to "On regularizing descriptor systems by output feedback"

In the above-mentioned paper by the authors (ibid., vol.39 p.1507-9 (1994)), linear time-invariant descriptor-variable systems were considered, and the problem of regularization as well as elimination of impulsive modes by output feedback was investigated. In this paper it is shown that if a certain portion of the descriptor vector is directly measurable, regularization and elimination of impulsive modes may be simplified. Furthermore, results of the article are extended to systems containing the first derivative of the input.