scispace - formally typeset
Book ChapterDOI

Greedy approximation algorithms for finding dense components in a graph

Reads0
Chats0
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.

read more

Citations
More filters
Patent

Method for enumerating cliques

TL;DR: In this article, the authors propose techniques for enumerating at least one maximal clique from a graph, where the data comprises a graph and a user-specified minimum size restriction on maximal cliques of interest is defined.
Journal ArticleDOI

A Contrast Metric for Fraud Detection in Rich Graphs

TL;DR: HoloScope introduces a novel metric “contrast suspiciousness” integrating information from graph topology and spikes to more accurately detect fraudulent users and objects, and provides theoretical bounds for how much this method increases the time cost needed for fraudsters to conduct adversarial attacks.
Journal ArticleDOI

Parallel algorithms for clustering biological graphs on distributed and shared memory architectures

TL;DR: This paper presents the design and evaluation of two different parallel implementations of a serial graph clustering heuristic called the Shingling heuristic, which was developed by Gibson et al.
Posted Content

EnsemFDet: An Ensemble Approach to Fraud Detection based on Bipartite Graph.

TL;DR: This paper proposes an Ensemble based Fraud DETection (ENSEMFDET) method to scale up fraud detection in bipartite graphs by oversampling the graph and solving the subproblems, the ensemble approach further votes suspicious nodes without sacrificing the prediction accuracy.
Journal ArticleDOI

Finding events in temporal networks: segmentation meets densest subgraph discovery

TL;DR: This paper model events as dense subgraphs that occur within intervals of network activity that capture the most interesting events during the network lifetime, and shows that on static graphs a simple greedy algorithm leads to approximate solution due to submodularity.
References
More filters
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.