Simon Scerri

A systematic review of open government data initiatives

Abstract We conduct a systematic survey with the aim of assessing open government data initiatives, that is; any attempt, by a government or otherwise, to open data that is produced by a governmental entity. We describe the open government data life-cycle and we focus our discussion on publishing and consuming processes required within open government data initiatives. We cover current approaches undertaken for such initiatives, and classify them. A number of evaluations found within related literature are discussed, and from them we extract challenges and issues that hinder open government initiatives from reaching their full potential. In a bid to overcome these challenges, we also extract guidelines for publishing data and provide an integrated overview. This will enable stakeholders to start with a firm foot in a new open government data initiative. We also identify the impacts on the stakeholders involved in such initiatives.

Distributed Knowledge Representation on the Social Semantic Desktop: Named Graphs, Views and Roles in NRL

The vision of the Social Semantic Desktopdefines a users personal information environment as a source and end-point of the Semantic Web: Knowledge workers comprehensively express their information and data with respect to their own conceptualizations. Semantic Web languages and protocols are used to formalize these conceptualizations and for coordinating local and global information access. From the way this vision is being pursued in the NEPOMUK project, we identified several requirements and research questions with respect to knowledge representation. In addition to the general question of the expressivity needed in such a scenario, two main challenges come into focus: i) How can we cope with the heterogeneity of knowledge models and ontologies, esp. multiple knowledge modules with potentially different interpretations? ii) How can we support the tailoring of ontologies towards different needs in various exploiting applications? In this paper, we present NRL, an approach to these two question that is based on named graphs for the modularization aspect and a view concept for the tailoring of ontologies. This view concept turned out to be of additional value, as it also provides a mechanism to impose different semantics on the same syntactical structure. We think that the elements of our approach are not only adequate for the semantic desktop scenario, but are also of importance as building blocks for the general Semantic Web.

Semantic email as a communication medium for the social semantic desktop

In this paper, we introduce a formal email workflow model based on traditional email, which enables the user to define and execute ad-hoc workflows in an intuitive way. This model paves the way for semantic annotation of implicit, well-defined workflows, thus making them explicit and exposing the missing information in a machine processable way. Grounding this work within the Social Semantic Desktop [1] via appropriate ontologies means that this information can be exploited for the benefit of the user. This will have a direct impact on their personal information management - given email is not just a major channel of data exchange between desktops, but it also serves as a virtual working environment where people collaborate. Thus the presented workflow model will have a concrete manifestation in the creation, organization and exchange of semantic desktop data.

An Ontology-Based Technique for Online Profile Resolution

Instance matching targets the extraction, integration and matching of instances referring to the same real-world entity. In this paper we present a weighted ontology-based user profile resolution technique which targets the discovery of multiple online profiles that refer to the same person identity. The elaborate technique takes into account profile similarities at both the syntactic and semantic levels, employing text analytics on top of open data knowledge to improve its performance. A two-staged evaluation of the technique performs various experiments to determine the best out of alternative approaches. These results are then considered in an improved algorithm, which is evaluated by real users, based on their real social network data. Here, a profile matching precision rate of 0.816 is obtained. The presented Social Semantic Web technique has a number of useful applications, such as detection of untrusted known persons behind anonymous profiles, and information sharing management across multiple social networks.

Semanta --- Semantic Email Made Easy

In this paper we present Semanta --- a fully-implemented system supporting Semantic Email Processes, integrated into the existing technical landscape and using existing email transport technology. By applying Speech Act Theory, knowledge about these processes can be made explicit, enabling machines to support email users with correctly interpreting, handling and keeping track of email messages, visualizing email threads and workflows, and extracting tasks and appointments from email messages. Whereas complex theoretical models and semantics are hidden beneath a simple user interface, the enabled functionalities are clear for the users to see and take advantage of. The systems evaluation proved that our experiment with Semanta has indeed been successful and that semantic technology can be applied as an extra layer to existing technology, thus bringing its benefits into everyday computer usage.

Technologies for the Social Semantic Desktop

The vision of the Social Semantic Desktop defines a users personal information environment as a source and end-point of the Semantic Web: Knowledge workers comprehensively express their information and data with respect to their own conceptualizations. Semantic Web languages and protocols are used to formalize these conceptualizations and for coordinating local and global information access. A core challenge is to integrate existing legacy Desktop data into the Social Semantic Desktop. Semantic lifting is the process of capturing the semantics of various types of (semi-)structured data and/or non-semantic metadata and translating such data into Semantic Web conceptualizations. From the way the vision of the Social Semantic Desktop is being pursued in the NEPOMUK project, we identified several requirements and research questions with respect to knowledge representation. In addition to the general question of the expressivity needed in such a scenario, two main challenges come into focus: i) How can we cope with the heterogeneity of knowledge models and ontologies, esp. multiple knowledge modules with potentially different interpretations? ii) How can we support the tailoring of ontologies towards different needs in various exploiting applications? In this paper, we present semantic lifting as a means to create semantic metadata and the Nepomuk Representation Language (NRL) as a means to represent these metadata. NRL is an approach to these two aforementioned questions that is based on named graphs for the modularization aspect and a view concept for the tailoring of ontologies. This view concept turned out to be of additional value, as it also provides a mechanism to impose different semantics on the same syntactical structure. We furthermore present some of the ontologies that have been developed with the help of NRL in the NEPOMUK project to build the semantic foundations for the Social Semantic Desktop.

Context-Aware, Trust-Based Access Control for the di.me Userware

Trust calculation to inform privacy recommendations based on context information involvement (e.g. location information, nearby people) is an increasing need in pervasive environments. In this paper we present a multidimensional trust metric designed for access control decisions in scenarios of the EU funded digital.me project. Thereby each involved context information could represent a separate trust dimension. In the focus is the correctness of the suggested trust metric towards meaningful privacy recommendations and improvement of access control decisions for our scenarios. The suggested metric could help to avoid manipulations and attacks based on fundamental requirements for situational trust. Our proposed trust calculation considers a presence history of persons at locations, to increase the accuracy of our base trust value. We present our approach after explaining the fundamental requirements, the underlying ontology framework and architecture.

A Requirements-Driven Approach Towards Decentralized Social Networks

A new generation of distributed social networks is promising to give back users full control over their personal information as shared in private and business life. However, there are many aspects to this control, such as information ownership, access to third parties and limited persistence. This paper compares various existing solutions against an analytically elaborated list of user requirements. Based on this comparison, we also present a comprehensive and integrated approach to overcome the major issues outlined for the existing solutions, including first experiences of applying the reference implementation.

Improving Email Conversation Efficiency through Semantically Enhanced Email

Despite persisting in popularity email is still plagued with information overload, hindering the workflow of data the user has to handle. While the revolutionization of the Web by the semantic Web is underway, we aspire to use the same technology to enhance electronic mail with useful semantics. In so doing we will tackle one of the largest flaws of the email communication genre - the lack of shared expectations about the form and content of the interaction. This can be attributed to the lack of explicit semantics covering the context and content of exchanged email messages. Earlier research showed that email content can be captured by applying speech act theory. We will refine and extend this work to develop an ontology for email speech acts and outline non-deterministic models to support the user in deciding the best course of action upon sending or receiving an email.

Integrating Tagging into the Web of Data: Overview and Combination of Existing Tag Ontologies

As the number of social websites offering tagging facilities increases, tagging has become not only a common basis for user participation, but also an important aspect of social content. Tagging is primarily based on the users participation and interaction, including the sharing and the exchange of their interests. However, even though users can collect and share tagging data with conventional technologies, this data is fragmentary and remains disconnected. Therefore, discovering content across independent sites remains a challenge. On the other hand, technologies of the Web of Data, and especially ontologies, help towards this goal of integrating tagged data. In this paper, we investigate the core features of existing tag ontologies that attempt to represent a common conceptualization of tagging and that provide well-defined semantics for tagging data, allowing for the sharing and interlinking of tagging data across independent sites or communities.