Two approaches to the computation of electrothermal processes at induction heating of moving ingots – by field theory and thermal circuit theory - A. A. Shcherba; O. D. Podoltsev; I. M. Kucheriava; V. M. Zolotarov; R. V. Bilianin (Proceedings of the Institute of Electrodynamics of the National Academy of Sciences of Ukraine, 2021)