QML-Morven : a framework for learning qualitative models

• Main Author: Pang, Wei
• Published: University of Aberdeen 2009
• Subjects: 006.3; Qualitative reasoning : Artificial intelligence
• Online Access: http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.499701

<p class="Abstract">The work proposed in this thesis continues the research into qualitative model learning (QML), a branch of qualitative reasoning.&nbsp; After the investigation of all existing qualitative model learning systems, especially the state-of-the-art system ILP-QSI, a novel system named QML-Morven is presented. <p class="Abstract">QML-Morven inherits many essential features of the existing QML systems: it can learn models from positive only data, make use of the well-posed model constraints, process hidden variables, learn models from incomplete data, and perform systematic experiments to verify the hypotheses being made by researchers. <p class="Abstract">The development of QML-Morven allows us to further investigate some interesting yet unsolved questions in the QML research.&nbsp; As a result, four significant hypotheses are tested and validated by performing a series of systematic experiments with QML-Morven:&nbsp; 1. The information of state variables and the number of hidden variables are two important actors that can influence the learning, and the different combination of these two factors may give a different learning result in terms of the kernel subset (minimal data for a successful learning) and learning precision; 2. The scalability of QML may be improved by the use of an evolutionary algorithm; 3. For some models, the kernel subsets can be constructed by combining several sets of qualitative states, and the states in a kernel subset tend to scatter over the solution space; 4. The integration of domain-specific knowledge makes QML more applicable for learning the qualitative models of the real-world dynamic systems of high complexity. <p class="Abstract">The results and analysis of these experiments with respect to QML-Morven also raise many questions and indicates several new research directions.&nbsp; In the final part of this thesis, several possible future directions are explored.