Numerical investigation of limit cycles to a non-Hamiltonian perturbed integrable system

According to the detection functions and qualitative analysis, we investigated the limit cycle bifurcations in a non-Hamiltonian perturbed integrable system. By numerical simulations, the distributed orderliness of the 4 limit cycles is observed, and their exact places are determined. The investigation also indicates that each of the 4 limit cycles passes the corresponding exact point.