  The technique of degree of randomness is used to model the correlations in
sequences containing various subsignals and noise. Kolmogorov stochasticity
parameter enables to quantify the randomness in number sequences and hence
appears as an efficient tool to distinguish the signals. Numerical experiments
for a broad class of composite signals of regular and random properties enable
to obtain the qualitative and quantitative criteria for the behavior of the
descriptor depending on the input parameters typical to astrophysical signals.
