“…The problems of restoration of a system input and coefficients arise in various applications such as metrology [1][2][3][4], image processing [5,6], spectroscopy [7], geophysics [8,9], process control [10], engineering [11,12], medicine [13,14], and many others. The identification of the virus spread models, i.e., the restoration of the coefficients of the corresponding differential equations, became crucial in the period of coronavirus pandemic (see, e.g., [15,16]) for constructing reliable forecasts of the pandemic evolution. These problems belong to a wide class of ill-posed (inverse) problems [17][18][19].…”