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A degree-corrected distribution-free model is proposed for weighted social networks with latent structural information. The model extends the previous distribution-free models by considering variation in node degree to fit real-world…

Social and Information Networks · Computer Science 2024-04-08 Huan Qing

Modularity is a very widely used measure of the level of clustering or community structure in networks. Here we consider a recent generalisation of the definition of modularity to temporal graphs, whose edge-sets change over discrete…

Combinatorics · Mathematics 2025-07-24 Vilhelm Agdur , Jessica Enright , Laura Larios-Jones , Kitty Meeks , Fiona Skerman , Ella Yates

Modularity is designed to measure the strength of division of a network into clusters (known also as communities). Networks with high modularity have dense connections between the vertices within clusters but sparse connections between…

Probability · Mathematics 2017-07-18 Liudmila Ostroumova Prokhorenkova , Pawel Pralat , Andrei Raigorodskii

Graph clustering plays a pivotal role in unsupervised learning methods like spectral clustering, yet traditional methods for graph clustering often perpetuate bias through unfair graph constructions that may underrepresent some groups. The…

Machine Learning · Computer Science 2025-12-11 Adithya K Moorthy , V Vijaya Saradhi , Bhanu Prasad

Communities of vertices within a giant network such as the World-Wide Web are likely to be vastly smaller than the network itself. However, Fortunato and Barth\'{e}lemy have proved that modularity maximization algorithms for community…

Physics and Society · Physics 2013-05-29 Jonathan W. Berry , Bruce Hendrickson , Randall A. LaViolette , Cynthia A. Phillips

We study a problem motivated by a question related to quantum-error-correcting codes. Combinatorially, it involves the following graph parameter: $$f(G)=\min\set{|A|+|\{x\in V\setminus A : d_A(x)\text{is odd}\}| : A\neq\emptyset},$$ where…

Combinatorics · Mathematics 2009-03-13 Tom Bohman , Andrzej Dudek , Alan Frieze , Oleg Pikhurko

When analyzing complex networks a key target is to uncover their modular structure, which means searching for a family of modules, namely node subsets spanning each a subnetwork more densely connected than the average. This work proposes a…

Discrete Mathematics · Computer Science 2018-09-10 Giovanni Rossi

We consider a large class of random geometric graphs constructed from samples $\mathcal{X}_n = \{X_1,X_2,\ldots,X_n\}$ of independent, identically distributed observations of an underlying probability measure $\nu$ on a bounded domain…

Probability · Mathematics 2016-04-15 Erik Davis , Sunder Sethuraman

Graph Neural Networks (GNNs) have improved unsupervised community detection of clustered nodes due to their ability to encode the dual dimensionality of the connectivity and feature information spaces of graphs. Identifying the latent…

Machine Learning · Computer Science 2023-11-28 William Leeney , Ryan McConville

A prominent parameter in the context of network analysis, originally proposed by Watts and Strogatz (Collective dynamics of `small-world' networks, Nature 393 (1998) 440-442), is the clustering coefficient of a graph $G$. It is defined as…

Combinatorics · Mathematics 2016-11-21 Michael Gentner , Irene Heinrich , Simon Jäger , Dieter Rautenbach

Many complex networks display a mesoscopic structure with groups of nodes sharing many links with the other nodes in their group and comparatively few with nodes of different groups. This feature is known as community structure and encodes…

Physics and Society · Physics 2009-07-31 Andrea Lancichinetti , Santo Fortunato

Measuring graph clustering quality remains an open problem. To address it, we introduce quality measures based on comparisons of intra- and inter-cluster densities, an accompanying statistical test of the significance of their differences…

Social and Information Networks · Computer Science 2020-03-20 Pierre Miasnikof , Alexander Y. Shestopaloff , Anthony J. Bonner , Yuri Lawryshyn , Panos M. Pardalos

Modularity introduced by Newman and Girvan [Phys. Rev. E 69, 026113 (2004)] is a quality function for community detection. Numerous methods for modularity maximization have been developed so far. In 2007, Barber [Phys. Rev. E 76, 066102…

Social and Information Networks · Computer Science 2015-06-05 Atsushi Miyauchi , Noriyoshi Sukegawa

We prove new lower bounds on the modularity of graphs. Specifically, the modularity of a graph $G$ with average degree $\bar d$ is $\Omega(\bar{d}^{-1/2})$, under some mild assumptions on the degree sequence of $G$. The lower bound…

Combinatorics · Mathematics 2023-07-17 Vilhelm Agdur , Nina Kamčev , Fiona Skerman

Spectral clustering methods which are frequently used in clustering and community detection applications are sensitive to the specific graph constructions particularly when imbalanced clusters are present. We show that ratio cut (RCut) or…

Machine Learning · Statistics 2016-11-18 Cem Aksoylar , Jing Qian , Venkatesh Saligrama

It has been hypothesized that some form of "modular" structure in artificial neural networks should be useful for learning, compositionality, and generalization. However, defining and quantifying modularity remains an open problem. We cast…

Machine Learning · Computer Science 2022-06-23 Richard D. Lange , David S. Rolnick , Konrad P. Kording

Modular Decomposition focuses on repeatedly identifying a module M (a collection of vertices that shares exactly the same neighbourhood outside of M) and collapsing it into a single vertex. This notion of exactitude of neighbourhood is very…

Discrete Mathematics · Computer Science 2021-01-25 Michel Habib , Lalla Mouatadid , Eric Sopena , Mengchuan Zou

A wide variety of complex networks (social, biological, information etc.) exhibit local clustering with substantial variation in the clustering coefficient (the probability of neighbors being connected). Existing models of large graphs…

Discrete Mathematics · Computer Science 2017-09-28 Samantha Petti , Santosh Vempala

We study community structure of networks. We have developed a scheme for maximizing the modularity Q based on mean field methods. Further, we have defined a simple family of random networks with community structure; we understand the…

Data Analysis, Statistics and Probability · Physics 2009-11-13 Sune Lehmann , Lars Kai Hansen

The graph of communities is a network emerging above the level of individual nodes in the hierarchical organisation of a complex system. In this graph the nodes correspond to communities (highly interconnected subgraphs, also called modules…

Statistical Mechanics · Physics 2007-05-23 Peter Pollner , Gergely Palla , Tamas Vicsek