17,294 research outputs found

    The role of earth observation in an integrated deprived area mapping “system” for low-to-middle income countries

    Get PDF
    Urbanization in the global South has been accompanied by the proliferation of vast informal and marginalized urban areas that lack access to essential services and infrastructure. UN-Habitat estimates that close to a billion people currently live in these deprived and informal urban settlements, generally grouped under the term of urban slums. Two major knowledge gaps undermine the efforts to monitor progress towards the corresponding sustainable development goal (i.e., SDG 11—Sustainable Cities and Communities). First, the data available for cities worldwide is patchy and insufficient to differentiate between the diversity of urban areas with respect to their access to essential services and their specific infrastructure needs. Second, existing approaches used to map deprived areas (i.e., aggregated household data, Earth observation (EO), and community-driven data collection) are mostly siloed, and, individually, they often lack transferability and scalability and fail to include the opinions of different interest groups. In particular, EO-based-deprived area mapping approaches are mostly top-down, with very little attention given to ground information and interaction with urban communities and stakeholders. Existing top-down methods should be complemented with bottom-up approaches to produce routinely updated, accurate, and timely deprived area maps. In this review, we first assess the strengths and limitations of existing deprived area mapping methods. We then propose an Integrated Deprived Area Mapping System (IDeAMapS) framework that leverages the strengths of EO- and community-based approaches. The proposed framework offers a way forward to map deprived areas globally, routinely, and with maximum accuracy to support SDG 11 monitoring and the needs of different interest groups

    A customisable pipeline for continuously harvesting socially-minded Twitter users

    Full text link
    On social media platforms and Twitter in particular, specific classes of users such as influencers have been given satisfactory operational definitions in terms of network and content metrics. Others, for instance online activists, are not less important but their characterisation still requires experimenting. We make the hypothesis that such interesting users can be found within temporally and spatially localised contexts, i.e., small but topical fragments of the network containing interactions about social events or campaigns with a significant footprint on Twitter. To explore this hypothesis, we have designed a continuous user profile discovery pipeline that produces an ever-growing dataset of user profiles by harvesting and analysing contexts from the Twitter stream. The profiles dataset includes key network and content-based users metrics, enabling experimentation with user-defined score functions that characterise specific classes of online users. The paper describes the design and implementation of the pipeline and its empirical evaluation on a case study consisting of healthcare-related campaigns in the UK, showing how it supports the operational definitions of online activism, by comparing three experimental ranking functions. The code is publicly available.Comment: Procs. ICWE 2019, June 2019, Kore

    Fake Profile Identification on Online Social Networks

    Get PDF
    Online social networks are web-based applications that allow user to communicate and share knowledge and information. The number of users who make use of these platforms are experiencing rapid growth both in profile creation and social interaction. However, intruders and malicious attackers have found their way into the networks, using fake profiles, thus exposing user to serious security and privacy problem.  Every user in the online social network should verify and authenticate their identities, with the other users as they interact. However, currently verification of user’s profiles and identities is faced with challenges, to the extent that a user may represent their identity with many profiles without any effective method of identity verification. As a result of this vulnerability, attackers create fake profiles which they use in attacking the online social system. In addition, online social networks use a logically centered architecture, where their control and management are under a service; provider, who must be entrusted with the security of data and communication traces; this further increases the vulnerability to attacks and online threats. In this paper, we demonstrate the causes and effects of fake profiles on online social networks, and then provide a review of the state-of-the-art mechanism for identifying and mitigating fake profiles on online social networks. Keywords: online social networks, fake profiles, sybil attack, fake account
    • …
    corecore