Periphery Theory and Its Application to Air Pollution Forecast

The periphery phenomena and periphery definition as well as periphery theory are introduced; The basic structure of a periphery （jieke） of system is composed of both a wall, which defends system itself, and a gate ( or passage), through which the exchange between the system and its environment is carried out. In order to describe the periphery mathematically, perimeter set are presented. On the basis two indicant functions: security degree and subsist ratio are suggested. By using air pollution and meteorological data, a case of air pollution forecast is exemplified in detail.