156,704 research outputs found
How people make friends in social networking sites - A microscopic perspective
We study the detailed growth of a social networking site with full temporal
information by examining the creation process of each friendship relation that
can collectively lead to the macroscopic properties of the network. We first
study the reciprocal behavior of users, and find that link requests are quickly
responded to and that the distribution of reciprocation intervals decays in an
exponential form. The degrees of inviters/accepters are slightly negatively
correlative with reciprocation time. In addition, the temporal feature of the
online community shows that the distributions of intervals of user behaviors,
such as sending or accepting link requests, follow a power law with a universal
exponent, and peaks emerge for intervals of an integral day. We finally study
the preferential selection and linking phenomena of the social networking site
and find that, for the former, a linear preference holds for preferential
sending and reception, and for the latter, a linear preference also holds for
preferential acceptance, creation, and attachment. Based on the linearly
preferential linking, we put forward an analyzable network model which can
reproduce the degree distribution of the network. The research framework
presented in the paper could provide a potential insight into how the
micro-motives of users lead to the global structure of online social networks.Comment: 10 pages, 12 figures, 2 table
Modeling Relational Data via Latent Factor Blockmodel
In this paper we address the problem of modeling relational data, which
appear in many applications such as social network analysis, recommender
systems and bioinformatics. Previous studies either consider latent feature
based models but disregarding local structure in the network, or focus
exclusively on capturing local structure of objects based on latent blockmodels
without coupling with latent characteristics of objects. To combine the
benefits of the previous work, we propose a novel model that can simultaneously
incorporate the effect of latent features and covariates if any, as well as the
effect of latent structure that may exist in the data. To achieve this, we
model the relation graph as a function of both latent feature factors and
latent cluster memberships of objects to collectively discover globally
predictive intrinsic properties of objects and capture latent block structure
in the network to improve prediction performance. We also develop an
optimization transfer algorithm based on the generalized EM-style strategy to
learn the latent factors. We prove the efficacy of our proposed model through
the link prediction task and cluster analysis task, and extensive experiments
on the synthetic data and several real world datasets suggest that our proposed
LFBM model outperforms the other state of the art approaches in the evaluated
tasks.Comment: 10 pages, 12 figure
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Co-authorship in the age of cyberculture: Open Educational Resources at the Open University of the United Kingdom
Locating Open Educational Resources (OER) as a phenomenon of cyberculture, this paper presents a reflection on the possibilities of co-authorship that are entailed in OER initiatives of different natures and settings within a large organisation. A selection of OER-related projects and activities carried out at the Open University of United Kingdom (UKOU) are examined from the perspective of a comparative framework proposed by Okada (2010). The framework identifies key features and differences between ‘Closed’ and ‘Open’ Education, that is, respectively, formal education, which takes place within the constraints of institutional Virtual Learning Environments, and informal education, which is gradually taking place more widely in cyberspace. The paper is introduced with a succinct discussion of the connection between cyberculture and the emergence of OER, followed by a presentation of the comparative framework adopted. The UKOU´s structure and methods are then presented, and various projects are discussed. The article concludes by proposing a brief commentary on the creative potential that is being unleashed at the very boundaries between formal and informal educational spaces that cyberculture is challenging
Collective awareness platforms and digital social innovation mediating consensus seeking in problem situations
In this paper we show the results of our studies carried out in the framework of the European Project SciCafe2.0 in the area of Participatory Engagement models. We present a methodological approach built on participative engagements models and holistic framework for problem situation clarification and solution impacts assessment. Several online platforms for social engagement have been analysed to extract the main patterns of participative engagement. We present our own experiments through the SciCafe2.0 Platform and our insights from requirements elicitation
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