V. CONCLUSION
In this paper, FSPGA, which is an algorithm for discovering fuzzy structural patterns in the form of clusters in the attributed graph, is proposed. Compared with prevalent algorithms that take different properties of an attributed graph, including topology, attribute, and both of the aforementioned, FSPGA may find an optimal arrangement of clusters for vertices in an attributed graph by formulating the task as a fuzzy constrained optimization problem. As the adoption of fuzzy set theory when determining the cluster membership, FSPGA can detect overlapping clusters, while most of the prevalent algorithms cannot. The experimental results presented in this paper show that FSPGA may perform robustly and efficiently in different types graph data, compared with the classical, latest graph clustering algorithms, and fuzzy clustering algorithms. In future, we will intend to further improve the efficiency of FSPGA and develop a version of FSPGA that may discover hierarchical structural patterns in attributed graphs.