The research of the formation of phase portraits of linear second-order systems taking into account the dynamic characteristics of the modelIgor Kovalev, Nafisa Kulmurodova, Mikhail Saramud, Andrey Kalinin and Dmitry BorovinskyEPJ Web Conf., 318 (2025) 04007DOI: https://doi.org/10.1051/epjconf/202531804007