College of Computer Science and Technology Jilin University Changchun 130012 China;
MOE Key Laboratory of Symbolic Computation and Knowledge Engineering Jilin University Changchun 130012 China;
College of Computer Science and Technology Jilin University Changchun 130012 China;
MOE Key Laboratory of Symbolic Computation and Knowledge Engineering Jilin University Changchun 130012 China;
College of Instrumentation & Electrical Engineering Jilin University Changchun 130012 China;
College of Computer Science and Technology Jilin University Changchun 130012 China;
MOE Key Laboratory of Symbolic Computation and Knowledge Engineering Jilin University Changchun 130012 China;