Reachability of nonnegative equilibrium states for the semilinear vibrating string by varying its axial load and the gain of damping

Khapalov, Alexander Y.

ESAIM: Control, Optimisation and Calculus of Variations, Volume 12 (2006) p. 231-252

Global non-negative controllability of the semilinear parabolic equation governed by bilinear control

Khapalov, Alexander Y.

ESAIM: Control, Optimisation and Calculus of Variations, Volume 7 (2002) p. 269-283