Multilevel refinement based on neighborhood similarity

The multilevel graph partitioning strategy aims to reduce the computational cost of the partitioning algorithm by applying it on a coarsened version of the original graph. This strategy is very useful when large-scale networks are analyzed. To improve the multilevel solution, refinement algorithms have been used in the uncorsening phase. Typical refinement algorithms exploit network properties, for example minimum cut or modularity, but they do not exploit features from domain specific networks. For instance, in social networks partitions with high clustering coefficient or similarity between vertices indicate a better solution. In this paper, we propose a refinement algorithm (RSim) which is based on neighborhood similarity. We compare RSim with: 1. two algorithms from the literature and 2. one baseline strategy, on twelve real networks. Results indicate that RSim is competitive with methods evaluated for general domains, but for social networks it surpasses the competing refinement algorithms.CNPq (grant 151836-/2013-2)FAPESP (grants 2011/22749-8, 11/20451-1 and 2013/12191-5)CAPE

Coarsening effects on k-partite network classification

Abstract The growing data size poses challenges for storage and computational processing time in semi-supervised models, making their practical application difficult; researchers have explored the use of reduced network versions as a potential solution. Real-world networks contain diverse types of vertices and edges, leading to using k-partite network representation. However, the existing methods primarily reduce uni-partite networks with a single type of vertex and edge. We develop a new coarsening method applicable to the k-partite networks that maintain classification performance. The empirical analysis of hundreds of thousands of synthetically generated networks demonstrates the promise of coarsening techniques in solving large networks’ storage and processing problems. The findings indicate that the proposed coarsening algorithm achieved significant improvements in storage efficiency and classification runtime, even with modest reductions in the number of vertices, leading to over one-third savings in storage and twice faster classifications; furthermore, the classification performance metrics exhibited low variation on average

A review and comparative analysis of coarsening algorithms on bipartite networks

Coarsening algorithms have been successfully used as a powerful strategy to deal with data-intensive machine learning problems defined in bipartite networks, such as clustering, dimensionality reduction, and visualization. Their main goal is to build informative simplifications of the original network at different levels of details. Despite its widespread relevance, a comparative analysis of these algorithms and performance evaluation is needed. Additionally, some aspects of these algorithms’ current versions have not been explored in their original or complementary studies. In that regard, we strive to fill this gap, presenting a formal and illustrative description of coarsening algorithms developed for bipartite networks. Afterward, we illustrate the usage of these algorithms in a set of emblematic problems. Finally, we evaluate and quantify their accuracy using quality and runtime measures in a set of thousands of synthetic and real-world networks with various properties and structures. The presented empirical analysis provides evidence to assess the strengths and shortcomings of such algorithms. Our study is a unified and useful resource that provides guidelines to researchers interested in learning about and applying these algorithms