According to the arrangement of the State Flood Control and Drought Relief Headquarters, mountain flood prevention system was preliminarily built before the flood season of 2006 with the joint efforts of departments concerned, by applying the result of Studies on Mountain Flood Warning and Forecasting System Based on Distributed Hydrological Model that jointly comple.

The defensive system of fortress is a typical defensive system of "living with defending"of our country in ancient times.

This paper aims at comparing the above two cities from the geographical position,layout,structure and defensive system to have a deep understanding of the capitals during the Warring States Period.

Accordingly, measures on how to build a solid defense system are present.

As a major developing country China need to establish a defense system of cyber security in .

To set up an all-round defence system and ensure safety in network information has become an important problem demanding prompt solution and having a great influence upon the state s overall situation and long-term interests.

Then,the formula about detection probability of stealth craft is deduced and the shooting effectiveness model of air-defense system to stealth craft under radar net- works is given.