Fuzzy approximation operators based on internal/external factors analysis

Centered on the philosophic rule of the internal and external factors of the alteration and development of objects, the paper sets up a dynamic information system driven by the external factors. Accordingly, it proposes two pairs of fuzzy approximation operators based on internal/external factors analysis in dynamic information system. It applies the pairs into the study on the fuzzy actions of external factors and on the actions of fuzzy external factors on the alternation of information system.