Supporting Change-Aware Semantic Web Services

The Semantic Web is not only evolving into a provider of structured meaningful content and knowledge representation, but also into a provider of services. While most of these services support external users of the SW, we focus on a vital service within the SW – change management and adaptation. Change is a ubiquitous feature of the SW. In this paper, we propose a service architecture that embraces and utilises change to provide higher quality services. We introduce pilot implementations of two supporting services within this architecture

Issues in usability studies for alerting in digital libraries

Alerting Services inform users of Digital Libraries about new or changed content of their favorite Digital Library collection, or about new documents discussing a topic they are interested in. The users define their interest in form of subscriptions; the alerting service filters new or changed documents against all user subscriptions and notifies the users about matches found. To define their subscriptions, users may, e.g., select a journal from a list, or a topic from a classification. Few services support the definition of IR type queries, or advanced combinations of queries and metadata selections

Event notification services: analysis and transformation of profile definition languages

The integration of event information from diverse event notification sources is, as with meta-searching over heterogeneous search engines, a challenging task. Due to the complexity of profile definition languages, known solutions for heterogeneous searching cannot be applied for event notification. In this technical report, we propose transformation rules for profile rewriting. We transform each profile defined at a meta-service into a profile expressed in the language of each event notification source. Due to unavoidable asymmetry in the semantics of different languages, some superfluous information may be delivered to the meta-service. These notifications are then post-processed to reduce the number of spurious messages. We present a survey and classification of profile definition languages for event notification, which serves as basis for the transformation rules. The proposed rules are implemented in a prototype transformation module for a Meta-Service for event notification

TIP spatial index: efficient access to digital libraries in a context-aware mobile system

We present a framework for efficient, uniform, location-based access to digital library collections that are external to a context-aware mobile information system. Using a tourist Information system, we utilize a spatial index to manage the context of location. We show how access to resources from within and outside of the tourist information system can be carried out in a seamless manner. We show how the spatial index can be navigated to continually provide information to the user. An empirical evaluation of the navigation strategy versus traditional spatial searching shows that navigation is efficient and outperforms traditional spatial search. In conclusion, our work provides a strategy for context-aware mobile systems to co-operate with digital libraries in a seamless and efficient manner