Аннотация:In the case the front propagates in a medium with continuous
sources described by cubic nonlinearity, the occurrence of stationary
distributions is associated with inhomogeneities of the medium.
However, there are processes in which the unperturbed medium is homogeneous,
and the stationary distribution occurs at the boundary of
the unperturbed medium and the one perturbed by the front passage
through it. Such a situation can arise, for example, in models of combustion
or tumor growth. For such problems, the use of models with
modular nonlinearities turns out to be very successful. This study is
devoted to the development of such models.