关键词: 粗糙集模型, 变精度粗糙集, 程度粗糙集, 近似算子, 逻辑运算

Abstract: Based on logical AND requirement of precision and grade, a logical AND operation model of variable precision lower approximation operator and grade upper approximation operator was proposed. In the new model, precise description and basic properties were obtained. Macroscopic algorithm and microscopic algorithm were proposed and analyzed, and a conclusion was made that microscopic algorithm had advantages in space complexity. Finally the new model and the algorithms were illustrated by a medical example. The new model has extended variable precision rough set model, graded rough set model and classical rough set model partially, and corresponding properties of approximation operators are obtained in these models.

Key words: rough set model, variable precision rough set, graded rough set, approximation operator, logical operation