Then an approach was put forward to evaluate the potential risk of thermal runaway in exothermic reaction system by use of system safety index, and the equilibrium region o.

Starting from the securement problems in human realistic decision making, the concepts of the safety matrix, the safety index and the risk matrix are put forward in this paper.

This paper introduces comprehensive index calculation method of accident index,safety management index and safety index from several item indexes which are used to judge the enterprises\' safety condition.

Based on the construction of vegetable variety pollution dynamic response coefficient and cumulative influence coefficient, the concept of vegetable variety security index is presented, which was used to establish the vegetable variety security control system.

Calculation methods of accident index,safety management index and security index,etc were created.

And then, from the viewpoint of online intrusion detection in security database systems, it presents the design of the Real-Time Audit Intrusion Detection System for our national security database management system SDM4, analyses the improvement policy for the system, and gives the main algorithm implementation.