TY JOUR TI MATHEMATICAL STATEMENT OF THE OPTIMAL CONTROL PROBLEM FOR THE FIRST STAGE OF STYRENE POLYMERIZATION PROCESS KW styrene polymerization KW optimal control KW Hamiltonian KW adjoint functions JO Modern Technologies and Scientific and Technological Progress AU Kobozev, V.. AU Istomin, A.L. PY 2026 IS 2026 PB Federal State Funded Educational Establishment of Higher Education «Angarsk State Technical University»