Title
Hierarchical Core Decomposition in Parallel: From Construction to Subgraph Search
Abstract
The model of k-core discovers a novel hierarchical structure of a network, which has been widely applied in various areas, e.g., sociology, biology, and brain science. Based on the containment relations of k-cores with different <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$k$</tex> , the hierarchical core decomposition (HCD) of a graph formalizes the hierarchy of all k-cores for each possible <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$k$</tex> • HCD is effective in locating high-quality subgraphs (e.g., densest subgraph search) and exploring particular network phenomena (e.g., user engagement study). However, existing solutions of HCD are still not efficient enough, for both the hierarchy construction and the subgraph search on the hierarchy. In this paper, we propose the first parallel construction algorithm PHCD for HCD, using a new union-find-based paradigm, and the first parallel algorithm PBKS to search high-quality subgraphs from the hierarchy with respect to various community scoring metrics. We prove the problem of hierarchy construction is <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$\mathcal{P}$</tex> -complete (difficult to parallelize effectively). Despite the negative result, our PHCD has a near-linear time cost, and PBKS is time-optimal in score computation for most community metrics. Extensive experiments are conducted on 10 real-world networks, where our proposed parallel algorithms significantly outperform the existing solutions, for both the hierarchy construction and the subgraph search.
Year
DOI
Venue
2022
10.1109/ICDE53745.2022.00090
2022 IEEE 38th International Conference on Data Engineering (ICDE)
Keywords
DocType
ISSN
hierarchical decomposition,k core,parallel algorithm
Conference
1063-6382
ISBN
Citations 
PageRank 
978-1-6654-0884-4
0
0.34
References 
Authors
52
5
Name
Order
Citations
PageRank
Deming Chu100.34
Fan Zhang209.13
Wenjie Zhang31616105.67
Xuemin Lin45585307.32
Ying Zhang5128890.39