In the above-mentioned paper,(1) linear time-invariant descriptor-vari
able systems were considered, and the problem of regularization as wel
l as elimination of impulsive modes by output feedback was investigate
d. Here it will be shown that if a certain portion of the descriptor v
ector is directly measurable, regularization and elimination of impuls
ive modes may be simplified. Furthermore, results of the article are e
xtended to systems containing the first derivative of the input.