Foteini Alvanaki

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With the increasing popularity of Web 2.0 streams, people become overwhelmed by the available information. This is partly countered by tagging blog posts and tweets, so that users can filter messages according to their tags. However, this is insufficient for detecting newly emerging topics that are not reflected by a single tag but are rather expressed by(More)
Emergent topics are newly arising themes in news, blogs, or tweets, often implied by interesting and unexpected correlations of tags or entities. We present the enBlogue system for emergent topic detection. The name enBlogue reflects the analogy with emerging trends in fashion often referred to as en Vogue. EnBlogue continuously monitors Web 2.0 streams and(More)
In this work, we consider the continuous computation of correlations between co-occurring tags that appear in messages published in social media streams. The vast amount and pace these messages are created makes it necessary to parallelise the computation of correlations to various nodes in a computing cluster. The main challenge in this is to ensure that(More)
Everything is relative. Cars are compared by gas per mile, websites by page rank, students based on GPA, scientists by number of publications, and celebrities by beauty or wealth. In this paper, we study the characteristics of such entity rankings based on a set of rankings obtained from a popular Web portal. The obtained insights are integrated in our(More)
Halls of Fame are fascinating constructs. They represent the elite of an often very large amount of entities—persons, companies, products, countries etc. Beyond their practical use as static rankings, changes to them are particularly interesting—for decision making processes, as input to common media or novel narrative science applications, or simply(More)
Earth observation sciences, astronomy, and seismology have large data sets which have inherently rich spatial and geospatial information. In combination with large collections of semantically rich objects which have a large number of thematic properties, they form a new source of knowledge for urban planning, smart cities and natural resource management.(More)
The popularity, availability and sizes of point cloud data sets are increasing, thus raising interesting data management and processing challenges. Various software solutions are available for the management of point cloud data. A benchmark for point cloud data management systems was defined and it was executed for several solutions. In this paper we focus(More)
In this work we consider the continuous computation of set correlations over a stream of set-valued attributes, such as Tweets and their hashtags, social annotations of blog posts obtained through RSS, or updates to set-valued attributes of databases. In order to compute tag correlations in a distributed fashion, all necessary information has to be present(More)
3D digital city models, important for urban planning, are currently constructed from massive point clouds obtained through airborne LiDAR (Light Detection and Ranging). They are semantically enriched with information obtained from auxiliary GIS data like Cadastral data which contains information about the boundaries of properties, road networks, rivers,(More)