A rough set-based incremental approach for learning knowledge in dynamic incomplete information systems

• A matrix based incremental approach in dynamic incomplete information systems is presented.
• A rough set-based incremental model for learning knowledge under four binary relations is outlined.
• Two incremental learning algorithms under the variation of objects in dynamic incomplete information systems are developed.

With the rapid growth of data sets nowadays, the object sets in an information system may evolve in time when new information arrives. In order to deal with the missing data and incomplete information in real decision problems, this paper presents a matrix based incremental approach in dynamic incomplete information systems. Three matrices (support matrix, accuracy matrix and coverage matrix) under four different extended relations (tolerance relation, similarity relation, limited tolerance relation and characteristic relation), are introduced to incomplete information systems for inducing knowledge dynamically. An illustration shows the procedure of the proposed method for knowledge updating. Extensive experimental evaluations on nine UCI datasets and a big dataset with millions of records validate the feasibility of our proposed approach.