Ults entropy in the structure of natural and technical systems “natural environment–object of activity–population”Jelguja Khetsuriani, Yuriy Kokhanov, Irina Tkacheva, Dmitry Podoyniczyn and Alexandra KarasevaE3S Web of Conf., 413 (2023) 05004DOI: https://doi.org/10.1051/e3sconf/202341305004