“…We consider the NHBI process N(t), with t 0 = 0, characterized by λ n (t) = λ n + ν(t), with λ > 0, subject to periodic immigration phenomena that occur with intensity function (25). In Figure 7, the transition probabilities p j,n (t|0), given in (42) and in (43), for the NHBI process with constant birth rate and periodic immigration intensity function (25) are plotted as function of t for j = 0 and n = 0, 1, 2 for some choices of parameters.…”