RDF Graph Summarization Based on Node Characteristic and Centrality

The explosive growth of RDF data makes it difficult to be efficiently queried, understood and used. RDF graph (RDFG) summarization aims to extract the most relevant and crucial data as summaries according to different criteria. Current summarization approaches mainly apply single strategies such as graph structure, pattern mining or relevance metrics to calculate RDFG summaries. Different to the existing approaches, this paper proposes a summarization approach to automatically generating RDFG summary, which can capture both structure and centrality information. Specifically, we present three algorithms, SumW (merging nodes based on node characteristics or similar types), SumS (merging nodes based on typed node characteristics) and SummaryFL (retrieving central nodes by combining node frequency and bridging coefficient). The three algorithms can be used by two summarization strategies: SumS or SumW only, and SumS+SummaryFL or SumW+SummaryFL. We conducted experiments over large and real-world RDF datasets to verify the effectiveness of our method with respect to time complexity, compression capability and coverage of the summary. The experiment results demonstrate that our approach outperformed the comparative algorithms.