Improved Algorithm and Further Research of β -reduct for variable precision rough set

In variable precision rough set, by introducing inclusion degree β, attribute reduction has been diversified. For example, in variable precision rough set, many researchers have studied β-reduct, β lower distribution reduct and β upper distribution reduct and so on. In this paper, we further research on β-reduct. We first discuss the monotonic characteristics of β lower and β upper approximation with the changes of the parameter β . Then we cite an example to illustrate the fact that with the change of the inclusion degree β, there is no monotonic characteristic in β-reduct. Finally, we develop an improved algorithm of finding β-reduct by considering the combinations among the condition equivalence classes.