Brittleness Theory and its Application on the Analysis of SARS

Brittleness as a characteristic of complex system has been presented. Complex system is chosen as the research object, which is characterized not only by openness, complexity, giant, evolution and emergence, hierarchy but also by brittleness. Moreover, it is existent objectively as the basic characteristic of complex system. Based on the definition, peculiarities, and models of brittleness, theories about brittleness of complex system have been established. In this paper, analysis has been carried out on the SARS based on the theory of brittleness. The results of simulation show that brittle entropy increase and brittle entropy of subsystems tend to ascend at the beginning of SARS interference. After the subsystems obtain the negative entropy from the environment, the entropy will be decreased. Understanding its internal brittle mechanism and adopting effective methods are the key factors of controlling the spread of SARS