Halas, Z.; Tvrdy, M.
(Нелінійні коливання, 2008)
We obtain an existence principle for the impulsive periodic boundary-value problem u’’ + cu’ = g(x) + e(t), u(ti+) = u(ti) + Ji(u, u’ ), u’(ti+) = u’(ti) + Mi(u, u’), i = 1, . . ., m, u(0) = u(T), u’(0) = u’(T), where g ∈ ...