Sum of positive Lyapunov exponents for Kuramoto–Sivashinsky equation

The sum of positive Lyapunov exponents expresses the entropy loss of the systems under study. The sum of positive Lyapunov exponents for Kuramoto–Sivashinsky equation is studied. Its time series behaves like the on–off intermittency. They have laminar and burst parts alternately. It is remarkable that the system in turbulent state loses its entropy intermittency-like.