201 research outputs found
On the discovery of social roles in large scale social systems
The social role of a participant in a social system is a label
conceptualizing the circumstances under which she interacts within it. They may
be used as a theoretical tool that explains why and how users participate in an
online social system. Social role analysis also serves practical purposes, such
as reducing the structure of complex systems to rela- tionships among roles
rather than alters, and enabling a comparison of social systems that emerge in
similar contexts. This article presents a data-driven approach for the
discovery of social roles in large scale social systems. Motivated by an
analysis of the present art, the method discovers roles by the conditional
triad censuses of user ego-networks, which is a promising tool because they
capture the degree to which basic social forces push upon a user to interact
with others. Clusters of censuses, inferred from samples of large scale network
carefully chosen to preserve local structural prop- erties, define the social
roles. The promise of the method is demonstrated by discussing and discovering
the roles that emerge in both Facebook and Wikipedia. The article con- cludes
with a discussion of the challenges and future opportunities in the discovery
of social roles in large social systems
Generating global network structures by triad types
This paper addresses the question of whether it is possible to generate
networks with a given global structure (defined by selected blockmodels, i.e.,
cohesive, core-periphery, hierarchical and transitivity), considering only
different types of triads. Two methods are used to generate networks: (i) the
method of relocating links; and (ii) the Monte Carlo Multi Chain algorithm
implemented in the "ergm" package implemented in R. Although all types of
triads can generate networks with the selected blockmodel types, the selection
of only a subset of triads improves the generated networks' blockmodel
structure. However, in the case of a hierarchical blockmodel without complete
blocks on the diagonal, additional local structures are needed to achieve the
desired global structure of generated networks. This shows that blockmodels can
emerge based on only local processes that do not take attributes into account
Friends don't lie: inferring personality traits from social network structure
In this work, we investigate the relationships between social network structure and personality; we assess the performances of different subsets of structural network features, and in particular those concerned with ego-networks, in predicting the Big-5 personality traits. In addition to traditional survey-based data, this work focuses on social networks derived from real-life data gathered through smartphones. Besides showing that the latter are superior to the former for the task at hand, our results provide a fine-grained analysis of the contribution the various feature sets are able to provide to personality classification, along with an assessment of the relative merits of the various networks exploited.European Commission (PERSI Project within the Marie Curie COFUND-FP7)Italy. Ministero dell'istruzione, dell'università e della ricerca (FIRB S-PATTERNS project
The Lifecycle and Cascade of WeChat Social Messaging Groups
Social instant messaging services are emerging as a transformative form with
which people connect, communicate with friends in their daily life - they
catalyze the formation of social groups, and they bring people stronger sense
of community and connection. However, research community still knows little
about the formation and evolution of groups in the context of social messaging
- their lifecycles, the change in their underlying structures over time, and
the diffusion processes by which they develop new members. In this paper, we
analyze the daily usage logs from WeChat group messaging platform - the largest
standalone messaging communication service in China - with the goal of
understanding the processes by which social messaging groups come together,
grow new members, and evolve over time. Specifically, we discover a strong
dichotomy among groups in terms of their lifecycle, and develop a separability
model by taking into account a broad range of group-level features, showing
that long-term and short-term groups are inherently distinct. We also found
that the lifecycle of messaging groups is largely dependent on their social
roles and functions in users' daily social experiences and specific purposes.
Given the strong separability between the long-term and short-term groups, we
further address the problem concerning the early prediction of successful
communities. In addition to modeling the growth and evolution from group-level
perspective, we investigate the individual-level attributes of group members
and study the diffusion process by which groups gain new members. By
considering members' historical engagement behavior as well as the local social
network structure that they embedded in, we develop a membership cascade model
and demonstrate the effectiveness by achieving AUC of 95.31% in predicting
inviter, and an AUC of 98.66% in predicting invitee.Comment: 10 pages, 8 figures, to appear in proceedings of the 25th
International World Wide Web Conference (WWW 2016
Online Social Networks: Measurements, Analysis and Solutions for Mining Challenges
In the last decade, online social networks showed enormous growth. With the rise
of these networks and the consequent availability of wealth social network data, Social
Network Analysis (SNA) led researchers to get the opportunity to access, analyse and
mine the social behaviour of millions of people, explore the way they communicate and
exchange information.
Despite the growing interest in analysing social networks, there are some challenges
and implications accompanying the analysis and mining of these networks. For example,
dealing with large-scale and evolving networks is not yet an easy task and still requires
a new mining solution. In addition, finding communities within these networks is a
challenging task and could open opportunities to see how people behave in groups on a
large scale. Also, the challenge of validating and optimizing communities without knowing
in advance the structure of the network due to the lack of ground truth is yet another
challenging barrier for validating the meaningfulness of the resulting communities.
In this thesis, we started by providing an overview of the necessary background and key
concepts required in the area of social networks analysis. Our main focus is to provide
solutions to tackle the key challenges in this area. For doing so, first, we introduce a predictive
technique to help in the prediction of the execution time of the analysis tasks for
evolving networks through employing predictive modeling techniques to the problem of
evolving and large-scale networks. Second, we study the performance of existing community
detection approaches to derive high quality community structure using a real email
network through analysing the exchange of emails and exploring community dynamics.
The aim is to study the community behavioral patterns and evaluate their quality within
an actual network. Finally, we propose an ensemble technique for deriving communities
using a rich internal enterprise real network in IBM that reflects real collaborations
and communications between employees. The technique aims to improve the community
detection process through the fusion of different algorithms
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