1,784 research outputs found
Finding Scientific Gems with Google
We apply the Google PageRank algorithm to assess the relative importance of
all publications in the Physical Review family of journals from 1893--2003.
While the Google number and the number of citations for each publication are
positively correlated, outliers from this linear relation identify some
exceptional papers or "gems" that are universally familiar to physicists.Comment: 6 pages, 4 figures, 2 tables, 2-column revtex4 forma
Racism in Advanced Capitalist Society: Comments on William J. Wilson\u27s The Truly Disadvantaged
Let me begin with words of praise. Bill Wilson\u27s The Truly Disadvantaged is a serious and important work. In it he alerts the nation to the alarming rise of social dislocation in Black inner city communities. But rather than joining with the conservative chorus which dominates political debate about this issue, Wilson focuses on the social structure, especially joblessness, as the key to the whole network of pathologies. Black inner city joblessness is, in turn, explained by large-scale economic shifts, interacting with a legacy of past racial discrimination, as well as various demographic factors. The result is the construction of a liberal analysis that challenges the dominant conservative position, which places the blame on the welfare system and ghetto subculture. Instead, Wilson claims, the blame lies with larger, social structural forces
Characterizing the dynamical importance of network nodes and links
The largest eigenvalue of the adjacency matrix of the networks is a key
quantity determining several important dynamical processes on complex networks.
Based on this fact, we present a quantitative, objective characterization of
the dynamical importance of network nodes and links in terms of their effect on
the largest eigenvalue. We show how our characterization of the dynamical
importance of nodes can be affected by degree-degree correlations and network
community structure. We discuss how our characterization can be used to
optimize techniques for controlling certain network dynamical processes and
apply our results to real networks.Comment: 4 pages, 4 figure
Exposing Multi-Relational Networks to Single-Relational Network Analysis Algorithms
Many, if not most network analysis algorithms have been designed specifically
for single-relational networks; that is, networks in which all edges are of the
same type. For example, edges may either represent "friendship," "kinship," or
"collaboration," but not all of them together. In contrast, a multi-relational
network is a network with a heterogeneous set of edge labels which can
represent relationships of various types in a single data structure. While
multi-relational networks are more expressive in terms of the variety of
relationships they can capture, there is a need for a general framework for
transferring the many single-relational network analysis algorithms to the
multi-relational domain. It is not sufficient to execute a single-relational
network analysis algorithm on a multi-relational network by simply ignoring
edge labels. This article presents an algebra for mapping multi-relational
networks to single-relational networks, thereby exposing them to
single-relational network analysis algorithms.Comment: ISSN:1751-157
Graph-based Features for Automatic Online Abuse Detection
While online communities have become increasingly important over the years,
the moderation of user-generated content is still performed mostly manually.
Automating this task is an important step in reducing the financial cost
associated with moderation, but the majority of automated approaches strictly
based on message content are highly vulnerable to intentional obfuscation. In
this paper, we discuss methods for extracting conversational networks based on
raw multi-participant chat logs, and we study the contribution of graph
features to a classification system that aims to determine if a given message
is abusive. The conversational graph-based system yields unexpectedly high
performance , with results comparable to those previously obtained with a
content-based approach
Immunization of networks with community structure
In this study, an efficient method to immunize modular networks (i.e.,
networks with community structure) is proposed. The immunization of networks
aims at fragmenting networks into small parts with a small number of removed
nodes. Its applications include prevention of epidemic spreading, intentional
attacks on networks, and conservation of ecosystems. Although preferential
immunization of hubs is efficient, good immunization strategies for modular
networks have not been established. On the basis of an immunization strategy
based on the eigenvector centrality, we develop an analytical framework for
immunizing modular networks. To this end, we quantify the contribution of each
node to the connectivity in a coarse-grained network among modules. We verify
the effectiveness of the proposed method by applying it to model and real
networks with modular structure.Comment: 3 figures, 1 tabl
Analysis of weighted networks
The connections in many networks are not merely binary entities, either
present or not, but have associated weights that record their strengths
relative to one another. Recent studies of networks have, by and large, steered
clear of such weighted networks, which are often perceived as being harder to
analyze than their unweighted counterparts. Here we point out that weighted
networks can in many cases be analyzed using a simple mapping from a weighted
network to an unweighted multigraph, allowing us to apply standard techniques
for unweighted graphs to weighted ones as well. We give a number of examples of
the method, including an algorithm for detecting community structure in
weighted networks and a new and simple proof of the max-flow/min-cut theorem.Comment: 9 pages, 3 figure
Grammar-Based Random Walkers in Semantic Networks
Semantic networks qualify the meaning of an edge relating any two vertices.
Determining which vertices are most "central" in a semantic network is
difficult because one relationship type may be deemed subjectively more
important than another. For this reason, research into semantic network metrics
has focused primarily on context-based rankings (i.e. user prescribed
contexts). Moreover, many of the current semantic network metrics rank semantic
associations (i.e. directed paths between two vertices) and not the vertices
themselves. This article presents a framework for calculating semantically
meaningful primary eigenvector-based metrics such as eigenvector centrality and
PageRank in semantic networks using a modified version of the random walker
model of Markov chain analysis. Random walkers, in the context of this article,
are constrained by a grammar, where the grammar is a user defined data
structure that determines the meaning of the final vertex ranking. The ideas in
this article are presented within the context of the Resource Description
Framework (RDF) of the Semantic Web initiative.Comment: First draft of manuscript originally written in November 200
Large-scale structure of time evolving citation networks
In this paper we examine a number of methods for probing and understanding
the large-scale structure of networks that evolve over time. We focus in
particular on citation networks, networks of references between documents such
as papers, patents, or court cases. We describe three different methods of
analysis, one based on an expectation-maximization algorithm, one based on
modularity optimization, and one based on eigenvector centrality. Using the
network of citations between opinions of the United States Supreme Court as an
example, we demonstrate how each of these methods can reveal significant
structural divisions in the network, and how, ultimately, the combination of
all three can help us develop a coherent overall picture of the network's
shape.Comment: 10 pages, 6 figures; journal names for 4 references fixe
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