An update algorithm of decision rules in expert systems based on rough sets theory
Yehong Han1, Lin Du1
COMPUTER MODELLING & NEW TECHNOLOGIES 2014 18(1) 156-163
1 Department of Computer, Qilu Normal University, Jinan, CHINA
The decision table in rough sets theory is a kind of prescription, which specifies what actions should be undertaken when some of conditions are satisfied. Therefore, this tool can be used as knowledge representation system in expert systems. Decision rules, which are obtained by simplification of decision tables, can be used as rationale of decision reasoning. In order to compute new decision rules on the decision table in which a new instance is added, new instances are classified three cases according to the relation between the new instance and the original set of decision rules in the paper, and the category is proved that it is a partition of new instances. According to the category, an update algorithm of decision rules based on rough sets theory in expert systems is presented, and the complexity of the algorithm is obtained.