Soliton Perturbations for a Combined KdV-MKdV Equation

The soliton perturbations for the combined Korteweg de Vries and modified Korteweg de Vries (KdV-MKdV) equation are studied. The first-order effects of perturbation on a soliton, namely both the slow time-dependence of the soliton parameters and the first-order correction are derived through constructing the appropriate Green's function.