Copyright © 2008 The Institute of Electronics, Information and Communication Engineers
Regular Section -- Papers -- Artificial Intelligence and Cognitive Science |
Structure Learning of Bayesian Networks Using Dual Genetic Algorithm*
1 The authors are with the CILAB, School of Electrical and Electronic Engineering, Yonsei University, 134, Shinchon-Dong, Sudaemun-ku, Seoul 120–749, Korea. E-mail: etkim{at}yonsei.ac.kr, 2 The author is with the School of Electrical and Electronic Engineering, Yonsei University, 134, Shinchon-Dong, Sudaemun-ku, Seoul 120–749, Korea.
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Abstract |
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A new structure learning approach for Bayesian networks (BNs) based on dual genetic algorithm (DGA) is proposed in this paper. An individual of the population is represented as a dual chromosome composed of two chromosomes. The first chromosome represents the ordering among the BN nodes and the second represents the conditional dependencies among the ordered BN nodes. It is rigorously shown that there is no BN structure that cannot be encoded by the proposed dual genetic encoding and the proposed encoding explores the entire solution space of the BN structures. In contrast with existing GA-based structure learning methods, the proposed method learns not only the topology of the BN nodes, but also the ordering among the BN nodes, thereby, exploring the wider solution space of a given problem than the existing method. The dual genetic operators are closed in the set of the admissible individuals. The proposed method is applied to real-world and benchmark applications, while its effectiveness is demonstrated through computer simulation.
Key Words: Bayesian network, genetic algorithms, structure learning, dual chromosomes
Manuscript received July 27, 2006. Manuscript revised June 25, 2007.
* This work was supported by the Ministry of Commerce, Industry and Energy of Korea (HISP).