Sobchuk V. S.
Ukr. Mat. Zh. - 1999. - 51, № 6. - pp. 827–834
We study periodic solutions and the behavior of phase trajectories of the differential equation of a nonlinear oscillator with pulse influence at unfixed moments of time.
Ukr. Mat. Zh. - 1992. - 44, № 9. - pp. 1209–1220
The present paper investigates the problem of constructing a separately continuous function defined on the product of two topological spaces that possesses a specified set of points of discontinuity and the related special problem of constructing a pointwise convergent sequence of continuous functions that possesses a specified set of points of nonuniform convergence and set of points of discontinuity of a limit function. In the metrizable case the former problem is solved for separable $F_σ$-sets whose projections onto every cofactor is of the first category. The second problem is solved for a pair of embedded $F_σ$.
On the article «Similarity theorem for Rn surfaces in Riemann space $R_m$» (Ukr. Math. J., vol. XVI, No. 3)
Ukr. Mat. Zh. - 1964. - 16, № 5. - pp. 712
Ukr. Mat. Zh. - 1964. - 16, № 3. - pp. 413-417