Despite the success of connectionist systems in prediction and classification problems, critics argue that the lack of symbol processing and explanation capability makes them less competitive than symbolic systems. Rule extraction from neural networks makes the interpretation of the behaviour of connectionist networks possible by relating sub-symbolic and symbolic processing. However, most rule extraction methods focus only on specific neural network architectures and present limited generalization performance. Support Vector Machine is an unsupervised learning method that has been recently applied successfully in many areas, and offers excellent generalization ability in comparison with other neural network, statistical, or symbolic machine learning models. In this thesis, an algorithm called Geometric and Oracle-Based Support Vector Machines Rule Extraction (GOSE) has been proposed to overcome the limitations of other rule-extraction methods by extracting comprehensible models from Support Vector Machines (SVM). This algorithm views the extraction as a geometric task. Given a trained SVM network, GOSE queries the synthetic instances and draws conjunction rules by approximating the optimization problem. The extracted rule set also represents the approximation of the SVM classification boundary. Unlike previous works in SVM rule-extraction, GOSE is broadly applicable to different networks and problems because it need not rely on training examples and network architectures. Theoretical proof guarantees that GOSE is capable of approximating the behavior of SVM networks. Empirical experiments are conducted on different SVM networks from binary classification networks to multi-class networks in various classification domains. The result of experiments demonstrates that GOSE can extract comprehensible rules with high levels of accuracy and fidelity for their corresponding networks. GOSE also exhibits superior consistency. After analyzing and applying several optimizing measures, the complexity of GOSE was improved. In brief, GOSE provides a novel way to explain how an SVM network functions.
| Identifer | oai:union.ndltd.org:bl.uk/oai:ethos.bl.uk:492352 |
| Date | January 2008 |
| Creators | Ren, Lu |
| Publisher | City University London |
| Source Sets | Ethos UK |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Source | http://openaccess.city.ac.uk/11917/ |
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