In order to study the property of random dynamic systems excited by narrow-band noiset,he complex normal form method was applied to narrow-band random dynamic systems.

Then,the normal form of the Hopf bifurcation was deduced by applying the Maple procedure of a normal form direct method.

From historian Kraph\'s point of view, Wu\'s case shows that the restoration of norms themselves gives foundation to explain the history, diachronically perspective getting started as a methodology to provide its historical objectivity, and the goal of the scientific study of the history should be to point to the present and the future.

Simplest normal form of non-resonance double Hopf bifurcation system with the complex normal form method;

Analysis of static bifurcation in electric power system based on normal form;

Homoclinic bifurcation of the strongly nonlinear oscillation system by the normal form method;

By analyzing the essence of iteration on the dual simplex algorithm and based on Linear Programming with normal form,this paper gains another improved dual simplex algorithm without bringing in surplus variables,which results in the same number of variables and reduced operational size.

We proved that a cost allocation function can be expressed by normal form if and only if it has anonymity, additionality and equivalency.