63,632 research outputs found
Growing networks of overlapping communities with internal structure
We introduce an intuitive model that describes both the emergence of
community structure and the evolution of the internal structure of communities
in growing social networks. The model comprises two complementary mechanisms:
One mechanism accounts for the evolution of the internal link structure of a
single community, and the second mechanism coordinates the growth of multiple
overlapping communities. The first mechanism is based on the assumption that
each node establishes links with its neighbors and introduces new nodes to the
community at different rates. We demonstrate that this simple mechanism gives
rise to an effective maximal degree within communities. This observation is
related to the anthropological theory known as Dunbar's number, i.e., the
empirical observation of a maximal number of ties which an average individual
can sustain within its social groups. The second mechanism is based on a
recently proposed generalization of preferential attachment to community
structure, appropriately called structural preferential attachment (SPA). The
combination of these two mechanisms into a single model (SPA+) allows us to
reproduce a number of the global statistics of real networks: The distribution
of community sizes, of node memberships and of degrees. The SPA+ model also
predicts (a) three qualitative regimes for the degree distribution within
overlapping communities and (b) strong correlations between the number of
communities to which a node belongs and its number of connections within each
community. We present empirical evidence that support our findings in real
complex networks.Comment: 14 pages, 8 figures, 2 table
A global approach to digital library evaluation towards quality interoperability
This paper describes some of the key research works related to my PhD thesis. The goal is the development of a global approach to digital library (DL) evaluation towards quality interoperability. DL evaluation has a vital role to play in building DLs, and in understanding and enhancing their role in society. Responding to two parallel research needs, the project is grouped around two tracks. Track one covers the theoretical approach, and provides an integrated evaluation model which overcomes the fragmentation of quality assessments; track two covers the experimental side, which has been undertaken through a comparative analysis of different DL evaluation methodologies, relating them to the conceptual framework. After presenting the problem dentition, current background and related work, this paper enumerates a set of research questions and hypotheses that I would like to address, and outlines the research methodology, focusing on a proposed evaluation framework and on the lessons learned from the case studies
Ongoing Pristina – Belgrade Talks: from Decentralization to Regional Cooperation and Future Perspectives. EDAP 4/2012
On 17 February 2008, Kosovo declared independence, ending its nine years unresolved status. The principal goal was, and remains, the need to involve different communities in the state structures. The new state, which aims to fulfil all the obligations set by the Ahtisaari plan, is trying to complete the decentralization process the implementation of which continuous to face obstacles in the two main communities: the Serbs and the Albanians. This article discusses matters related to community acceptance of the decentralization process, the functioning of the parallel structures, the situation in North Kosovo and the on - going talks between Pristina and Belgrade. The article provides evidences that while the implementation of the decentralization process is the best possibility for Kosovo, it must not follow only an ethnic line
Introduction : user studies for digital library development
Introductory chapter to the edited collection on user studies in digital library development. Contains a general introduction to the topic and biographical sketches of the contributors.peer-reviewe
Building communities for the exchange of learning objects: theoretical foundations and requirements
In order to reduce overall costs of developing high-quality digital courses (including both the content, and the learning and teaching activities), the exchange of learning objects has been recognized as a promising solution. This article makes an inventory of the issues involved in the exchange of learning objects within a community. It explores some basic theories, models and specifications and provides a theoretical framework containing the functional and non-functional requirements to establish an exchange system in the educational field. Three levels of requirements are discussed. First, the non-functional requirements that deal with the technical conditions to make learning objects interoperable. Second, some basic use cases (activities) are identified that must be facilitated to enable the technical exchange of learning objects, e.g. searching and adapting the objects. Third, some basic use cases are identified that are required to establish the exchange of learning objects in a community, e.g. policy management, information and training. The implications of this framework are then discussed, including recommendations concerning the identification of reward systems, role changes and evaluation instruments
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