On the controllability of linear systems with constant coefficients

In the case where the constraint set $\Omega$; contains the point $0$, by using the methods of linear algebra the problem of $0$-controllability of a linear system with constant coefficients is reduced to the problem of $0$-controllability of a linear system with constant coefficients and with a matrix whose eigenvalues are all real and positive. An analogous fact is derived for the problem of $0$-accessibility.
Bibliography: 10 titles.