30,411 research outputs found
Foundations and modelling of dynamic networks using Dynamic Graph Neural Networks: A survey
Dynamic networks are used in a wide range of fields, including social network
analysis, recommender systems, and epidemiology. Representing complex networks
as structures changing over time allow network models to leverage not only
structural but also temporal patterns. However, as dynamic network literature
stems from diverse fields and makes use of inconsistent terminology, it is
challenging to navigate. Meanwhile, graph neural networks (GNNs) have gained a
lot of attention in recent years for their ability to perform well on a range
of network science tasks, such as link prediction and node classification.
Despite the popularity of graph neural networks and the proven benefits of
dynamic network models, there has been little focus on graph neural networks
for dynamic networks. To address the challenges resulting from the fact that
this research crosses diverse fields as well as to survey dynamic graph neural
networks, this work is split into two main parts. First, to address the
ambiguity of the dynamic network terminology we establish a foundation of
dynamic networks with consistent, detailed terminology and notation. Second, we
present a comprehensive survey of dynamic graph neural network models using the
proposed terminologyComment: 28 pages, 9 figures, 8 table
Understanding and Predicting Delay in Reciprocal Relations
Reciprocity in directed networks points to user's willingness to return
favors in building mutual interactions. High reciprocity has been widely
observed in many directed social media networks such as following relations in
Twitter and Tumblr. Therefore, reciprocal relations between users are often
regarded as a basic mechanism to create stable social ties and play a crucial
role in the formation and evolution of networks. Each reciprocity relation is
formed by two parasocial links in a back-and-forth manner with a time delay.
Hence, understanding the delay can help us gain better insights into the
underlying mechanisms of network dynamics. Meanwhile, the accurate prediction
of delay has practical implications in advancing a variety of real-world
applications such as friend recommendation and marketing campaign. For example,
by knowing when will users follow back, service providers can focus on the
users with a potential long reciprocal delay for effective targeted marketing.
This paper presents the initial investigation of the time delay in reciprocal
relations. Our study is based on a large-scale directed network from Tumblr
that consists of 62.8 million users and 3.1 billion user following relations
with a timespan of multiple years (from 31 Oct 2007 to 24 Jul 2013). We reveal
a number of interesting patterns about the delay that motivate the development
of a principled learning model to predict the delay in reciprocal relations.
Experimental results on the above mentioned dynamic networks corroborate the
effectiveness of the proposed delay prediction model.Comment: 10 page
Predicting Scientific Success Based on Coauthorship Networks
We address the question to what extent the success of scientific articles is
due to social influence. Analyzing a data set of over 100000 publications from
the field of Computer Science, we study how centrality in the coauthorship
network differs between authors who have highly cited papers and those who do
not. We further show that a machine learning classifier, based only on
coauthorship network centrality measures at time of publication, is able to
predict with high precision whether an article will be highly cited five years
after publication. By this we provide quantitative insight into the social
dimension of scientific publishing - challenging the perception of citations as
an objective, socially unbiased measure of scientific success.Comment: 21 pages, 2 figures, incl. Supplementary Materia
Structured Review of the Evidence for Effects of Code Duplication on Software Quality
This report presents the detailed steps and results of a structured review of code clone literature. The aim of the review is to investigate the evidence for the claim that code duplication has a negative effect on code changeability. This report contains only the details of the review for which there is not enough place to include them in the companion paper published at a conference (Hordijk, Ponisio et al. 2009 - Harmfulness of Code Duplication - A Structured Review of the Evidence)
Transforming Graph Representations for Statistical Relational Learning
Relational data representations have become an increasingly important topic
due to the recent proliferation of network datasets (e.g., social, biological,
information networks) and a corresponding increase in the application of
statistical relational learning (SRL) algorithms to these domains. In this
article, we examine a range of representation issues for graph-based relational
data. Since the choice of relational data representation for the nodes, links,
and features can dramatically affect the capabilities of SRL algorithms, we
survey approaches and opportunities for relational representation
transformation designed to improve the performance of these algorithms. This
leads us to introduce an intuitive taxonomy for data representation
transformations in relational domains that incorporates link transformation and
node transformation as symmetric representation tasks. In particular, the
transformation tasks for both nodes and links include (i) predicting their
existence, (ii) predicting their label or type, (iii) estimating their weight
or importance, and (iv) systematically constructing their relevant features. We
motivate our taxonomy through detailed examples and use it to survey and
compare competing approaches for each of these tasks. We also discuss general
conditions for transforming links, nodes, and features. Finally, we highlight
challenges that remain to be addressed
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