34,620 research outputs found

    Interest communities and flow roles in directed networks: the Twitter network of the UK riots

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    Directionality is a crucial ingredient in many complex networks in which information, energy or influence are transmitted. In such directed networks, analysing flows (and not only the strength of connections) is crucial to reveal important features of the network that might go undetected if the orientation of connections is ignored. We showcase here a flow-based approach for community detection in networks through the study of the network of the most influential Twitter users during the 2011 riots in England. Firstly, we use directed Markov Stability to extract descriptions of the network at different levels of coarseness in terms of interest communities, i.e., groups of nodes within which flows of information are contained and reinforced. Such interest communities reveal user groupings according to location, profession, employer, and topic. The study of flows also allows us to generate an interest distance, which affords a personalised view of the attention in the network as viewed from the vantage point of any given user. Secondly, we analyse the profiles of incoming and outgoing long-range flows with a combined approach of role-based similarity and the novel relaxed minimum spanning tree algorithm to reveal that the users in the network can be classified into five roles. These flow roles go beyond the standard leader/follower dichotomy and differ from classifications based on regular/structural equivalence. We then show that the interest communities fall into distinct informational organigrams characterised by a different mix of user roles reflecting the quality of dialogue within them. Our generic framework can be used to provide insight into how flows are generated, distributed, preserved and consumed in directed networks.Comment: 32 pages, 14 figures. Supplementary Spreadsheet available from: http://www2.imperial.ac.uk/~mbegueri/Docs/riotsCommunities.zip or http://rsif.royalsocietypublishing.org/content/11/101/20140940/suppl/DC

    Managing ubiquitous eco cities: the role of urban telecommunication infrastructure networks and convergence technologies

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    A successful urban management system for a Ubiquitous Eco City requires an integrated approach. This integration includes bringing together economic, socio-cultural and urban development with a well orchestrated, transparent and open decision making mechanism and necessary infrastructure and technologies. Rapidly developing information and telecommunication technologies and their platforms in the late 20th Century improves urban management and enhances the quality of life and place. Telecommunication technologies provide an important base for monitoring and managing activities over wired, wireless or fibre-optic networks. Particularly technology convergence creates new ways in which the information and telecommunication technologies are used. The 21st Century is an era where information has converged, in which people are able to access a variety of services, including internet and location based services, through multi-functional devices such as mobile phones and provides opportunities in the management of Ubiquitous Eco Cities. This paper discusses the recent developments in telecommunication networks and trends in convergence technologies and their implications on the management of Ubiquitous Eco Cities and how this technological shift is likely to be beneficial in improving the quality of life and place. The paper also introduces recent approaches on urban management systems, such as intelligent urban management systems, that are suitable for Ubiquitous Eco Cities

    Big Data Privacy Context: Literature Effects On Secure Informational Assets

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    This article's objective is the identification of research opportunities in the current big data privacy domain, evaluating literature effects on secure informational assets. Until now, no study has analyzed such relation. Its results can foster science, technologies and businesses. To achieve these objectives, a big data privacy Systematic Literature Review (SLR) is performed on the main scientific peer reviewed journals in Scopus database. Bibliometrics and text mining analysis complement the SLR. This study provides support to big data privacy researchers on: most and least researched themes, research novelty, most cited works and authors, themes evolution through time and many others. In addition, TOPSIS and VIKOR ranks were developed to evaluate literature effects versus informational assets indicators. Secure Internet Servers (SIS) was chosen as decision criteria. Results show that big data privacy literature is strongly focused on computational aspects. However, individuals, societies, organizations and governments face a technological change that has just started to be investigated, with growing concerns on law and regulation aspects. TOPSIS and VIKOR Ranks differed in several positions and the only consistent country between literature and SIS adoption is the United States. Countries in the lowest ranking positions represent future research opportunities.Comment: 21 pages, 9 figure

    Networks Within Cities and Among Cities: A Paradigm for Urban Development and Governance

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    Networks and networking have become fashionable concepts and terms in regional science, and in particular in regional and urban geography in the last decade: we speak about network firms, network society, network economy but also network cities, city-networks, reti urbane, reseaux de villes. Only catch-words for somebody; a true new scientific paradigm according to others. Our opinion is that in fact we are confronted with a new paradigm in spatial sciences, under some precise conditions: - that its exact meaning is thoroughly defined, - that its theoretical economic rationale is justified, - that the novelty of its empirical content is clearly pointed out, with respect to more traditional spatial facts and processes that can easily be interpreted through existing spatial paradigms. The relevant theoretical building block on which the network concept or paradigm may be constructed are: - a new view of the economy as a system or web of links between individuals, firms and institutions, where links depend on experience and evolve through learning processes; the existing endowment of knowledge and other production factors is put into value through a relational capability addressed towards the exchange and collection of information, building reputation and trust, creating synergies, cutting down uncertainty, boosting learning processes; - the acknowledgement of cooperation as a new organisational and behavioural form, intermediate between hierarchy (internal development and merging of external activities through direct control) and market resort; cooperation networks among firms collaborating with each other on technological advances and innovation projects were the earlier phenomena that were abundantly explored in the past. In a spatial perspective, two phenomena in particular are worth exploring today through the network concept: - networking as cooperation among individuals, firms and institutions taking place inside the cities concerning collective action, public/private partnerships on large urban projects and the supply of public goods, and giving rise to new forms of urban governance; - networking as inter-urban cooperation, assuming the cities as economic actors, competing but also cooperating in the global arena where locations of internationally mobile factors (professionals, corporations, institutions) are decided and negotiated. The paper is organised in the following way: - a major section is devoted to the interpretation of the micro-economic efficiency of local networking (local urban networks), in terms of the usual criteria of optimal allocation of resources and collective welfare, viewing the network as an organisational alternative between market failure and state failure; - a transition section deals with the interpretation of cities, a collective actor at best, as individual/unitary economic actors, given the case for collective action among interest groups, the possibility of defining in broad terms a function of collective preference referring to non-mobile local actors, the engagement of public and private actors in processes of strategic planning and definition of shared visions for the future of the city vis-a-vis mobile actors; - another main section interprets competition and cooperation among cities (inter-city-networks) underlining advantages, risks and conditions for maximising overall comprehensive well-being. JEL classification: D70, H77, R58
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