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Book ChapterDOI

Greedy approximation algorithms for finding dense components in a graph

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TLDR
This paper gives simple greedy approximation algorithms for these optimization problems of finding subgraphs maximizing these notions of density for undirected and directed graphs and answers an open question about the complexity of the optimization problem for directed graphs.
Abstract
We study the problem of finding highly connected subgraphs of undirected and directed graphs. For undirected graphs, the notion of density of a subgraph we use is the average degree of the subgraph. For directed graphs, a corresponding notion of density was introduced recently by Kannan and Vinay. This is designed to quantify highly connectedness of substructures in a sparse directed graph such as the web graph. We study the optimization problems of finding subgraphs maximizing these notions of density for undirected and directed graphs. This paper gives simple greedy approximation algorithms for these optimization problems. We also answer an open question about the complexity of the optimization problem for directed graphs.

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Citations
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Proceedings ArticleDOI

Re-ranking of web image search results using a graph algorithm

TL;DR: The method re-ranks the results of text based systems by incorporating visual similarity of the resulting images by finding the densest component that corresponds to the largest set of most similar subset of images.
Proceedings ArticleDOI

Efficient Algorithms for Densest Subgraph Discovery on Large Directed Graphs

TL;DR: The notion of [ x, y]-core is introduced, which is a dense subgraph for G, and it is shown that the densest subgraph can be accurately located through the [x, y]core with theoretical guarantees.
Posted Content

Scalable Betweenness Centrality Maximization via Sampling

TL;DR: In this paper, the authors proposed a randomized algorithm for betweenness centrality maximization with high probability, where the cardinality constraint is a constant and the probability of finding the most central nodes is a function of the number of shortest paths passing through the top k nodes.
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Spectral Properties of Hypergraph Laplacian and Approximation Algorithms

TL;DR: In this paper, a non-linear hypergraph Laplacian operator based on a diffusion process on the hypergraph is introduced, such that within each hyperedge, measure flows from vertices having maximum weighted measure to those having minimum.
Journal ArticleDOI

Protein complex prediction for large protein protein interaction networks with the Core&Peel method

TL;DR: The algorithm Core&Peel pushes forward the state-of-the-art in PPIN clustering providing an algorithmic solution with polynomial running time that attains experimentally demonstrable good output quality and speed on challenging large real networks.
References
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Proceedings ArticleDOI

Authoritative sources in a hyperlinked environment

TL;DR: This work proposes and test an algorithmic formulation of the notion of authority, based on the relationship between a set of relevant authoritative pages and the set of \hub pages that join them together in the link structure, that has connections to the eigenvectors of certain matrices associated with the link graph.
Journal ArticleDOI

Trawling the Web for emerging cyber-communities

TL;DR: The subject of this paper is the systematic enumeration of over 100,000 emerging communities from a Web crawl, motivating a graph-theoretic approach to locating such communities, and describing the algorithms and algorithmic engineering necessary to find structures that subscribe to this notion.
Book ChapterDOI

The web as a graph: measurements, models, and methods

TL;DR: This paper describes two algorithms that operate on the Web graph, addressing problems from Web search and automatic community discovery, and proposes a new family of random graph models that point to a rich new sub-field of the study of random graphs, and raises questions about the analysis of graph algorithms on the Internet.
Proceedings ArticleDOI

Inferring Web communities from link topology

TL;DR: This investigation shows that although the process by which users of the Web create pages and links is very difficult to understand at a “local” level, it results in a much greater degree of orderly high-level structure than has typically been assumed.
Trending Questions (1)
Calculate the density of directed and undirected graph?

The density of a directed graph is defined as the maximum density of any subset of vertices, while the density of an undirected graph is defined as the maximum density of any subset of vertices.