While browsing the Web, providing profile information in social networking services, or tagging pictures, users leave a plethora of traces. In this paper, we analyze the nature of these traces. We investigate how user data is distributed across different Web systems, and examine ways to aggregate user profile information. Our analyses focus on both explicitly provided profile information (name,...

In this paper, we argue that realizing the vision of the Semantic Web as an open and global decentralized knowledge space would greatly benefit from the availability of a large-scale service which may enable the systematic reuse of URIs across independently produced Semantic Web contents. Such a service, which we call an Entity Name System (ENS), might play for the Semantic Web the role that th...

Insider attack has become a major threat in financial sector and is a very serious and pervasive security problem. Currently, there is no insider threat ontology in this domain and such an ontology is critical to developing countermeasures against insider attacks. In this paper, we create an ontology focusing on insider attacks in the banking domain targeting database systems. We define the tax...

We argue that for a personal agent working within a Semantic Web framework, machine learning is essential. We identify two topologies in the Semantic Web, and refer to these as: (1) semantic forests (disjoint trees) and (2) true semantic webs (complex interconnected graphs). An example of (1) is Citeseer BibTeX mapped to RDF; an example of (2) is FOAF, an RDF representation of people and their ...

This paper presents our work and experience interlinking educational information across universities through the use of Linked Data principles and technologies. More specifically this paper is focused on selecting, extracting, structuring and interlinking information of video lectures produced by 27 different educational institutions. For this purpose, selected information from several websites...

Social networks are important for the Semantic Web. Several means can be used to obtain social networks: using social networking services, aggregating Friendof-a-Friend (FOAF) documents, mining text information on the Web or in e-mail messages, and observing face-to-face communication using sensors. Integrating multiple social networks is a key issue for further utilization of social networks i...

Web-based social networks (WBSNs) are online communities where participants can establish relationships and share resources across the Web with other users. In recent years, several WBSNs have been adopting Semantic Web technologies, such as FOAF, for representing users’ data and relationships, making it possible to enforce information interchange across multiple WBSNs. Despite its advantages i...

In this paper, we describe a Bio-SAmI system, which is a Biomedical learning system that is context-aware and responsive to mobile learners sharing information on a social network. Bio-SAmI is a Web 2.0 enabled system which employees Social Ambient Intelligence techniques. The Bio-SAmI infrastructure is based on the Actor model that treats mobile users or “actors" as the universal primitives of...

We describe an approach to partitioning a large OWL ABox with respect to a TBox so that specific kinds of reasoning can be performed separately on each partition and the results trivially combined in order to achieve complete answers. The main features of our approach include: a reasonable tradeoff between the complexity of the task and the granularity of partitioning; worst-case polynomial tim...

This article investigates several well-known social network applications such as Facebook, LinkedIn, Last.fm, Flickr and identifies semantics and social data portability as the main technical issues that need to be addressed in the future. We argue that these issues can be addressed by building social networks like Semantic Web applications with FOAF, SIOC, and Linked Data technologies, and sho...