Aibns System Based On Bayesian Network Modeling And Its Applications

The focus of intelligent tutoring system (ITS) is to increase the adaptiveness and intelligentness of the long-range network education system. The student model is the foundation and core of ITS, the prerequisite of performance of other models. The article demonstrates that, in view of present student modeling of ITS in China, which is to simple and lack of intelligentness, Combined with some mature technology of artificial intelligence (AI), an ITS of AIBNS based on bayesian network (BN) has been developed.This thesis first analyses the advantages and disadvantages of the two kinds of modeling based on preparation relationship and inheritance relationship . After dividing knowledge item (KI) and learning network structure and parameter, the thesis puts forward a approach to form an overlay student model based on BN, and after modeling on domain related knowledge and independent information, it shows the student's knowledge structure in a specific field, which enables the model to have more strong calculation ability. In view of the existing uncertainty of the evaluation of cognition of students and the disturbance of abnormal reaction in calculation, it also gives out an adaptive item selection algorithm, which precisely evaluates cognition of students by using as few questions as possible, and reduces noise in the test of evaluation. And then it devices an evaluation model of cognition of students, based on fuzzy transformation principle, the model wihich can not only evaluate KI cognitionally, but carry out comprehensive evaluation of multiple grades, which has raised the precision of evaluation of cognition of stuents. The last part of this paper employs the way of expression of knowledge of object-oriented Bayesian networks (OOBN), and realizes a prototype system of AIBNS, which is helpful in the application of the theory of BN to the domain of ITS.AIBNS distinguishes from the traditional teaching model of "teaching as a leading role", and combines individual self-study with mutual and coordinative study, which can not only provide teaching resources adaptively according to the student's individuality, but give suggestion in view of study opjective, and show the user the procedure sequence of knowledge learning. It tests and verifies the intelligentness of ITS based on BN, and has sound mutuality and adaptiveness.