So if the power system cannot grasp the rule of power demand cycle fluctuation, it is unable to deal with the market change and satisfy the power demand of the entire society.

This paper analyses the random process of traffic flow fluctuation of the traffic control system and presents the subsystem quasi -junction method for the determination of signal cycle of the system.

Both domestic business cycle and economic fluctuation of the world have led to the insufficiency of aggregate DE - mand in China's present economy.