Along the bottom of Figure 1 are the three types of submission methods, with the vertical dashed lines indicating the point in the lifecycle at which that particular method will return.
沿着图1的底部，有三种提交方法，从上到下的点线表示具体的方法返回的生命周期中的时间点。
2
A method of keeping neutral point potential balanced based on three-level SPWM had been brought forward, which can improve output waveform and decrease the possibility of IGCT's over-voltage.
This paper construct measure system of road safety properties evaluation and corresponding method through three levels that are respectively point, line and area.