Abstract.A sizable amount of data on the Web is currently available via Web APIs that expose data in formats such as JSON or XML. Combining data from different APIs and data sources requires glue code which is typically not shared and hence not reused. We propose Linked Data Services (LIDS), a general, formalised approach for integrating dataproviding services with Linked Data, a popular mechanism for data publishing which facilitates data integration and allows for decentralised publishing. We present conventions for service access interfaces that conform to Linked Data principles, and an abstract lightweight service description formalism. We develop algorithms that use LIDS descriptions to automatically create links between services and existing data sets. To evaluate our approach, we realise LIDS wrappers and LIDS descriptions for existing services and measure performance and effectiveness of an automatic interlinking algorithm over multiple billions of triples.

Abstract. Numerous forms of policies, licensing terms, and related conditions are associated with Web data and services. A natural goal for facilitating the reuse and re-combination of such content is to model usage policies as part of the data so as to enable their exchange and automated processing. This paper thus proposes a concrete policy modelling language. A particular diAEculty are self-referential policies such as Creative Commons ShareAlike, that mandate that derived content is published under some license with the same permissions and requirements. We present a general semantic framework for evaluating such recursive statements, show that it has desirable formal properties, and explain how it can be evaluated using existing tools. We then show that our approach is compatible with both OWL DL and Datalog, and illustrate how one can concretely model self-referential policies in these languages to obtain desired conclusions.

WS-Policy is a standard to express requirements and capabilities in Web service systems. Policies are based on domain-specific assertions. In this paper we present a lightweight approach to semantic annotations of policy assertions. The approach allows matching of requirements and capabilities based not only on the syntactical representation of their corresponding assertions but also on their semantic meaning. Besides vocabulary mismatches our approach can also handle granularity mismatches, e.g. if two capabilities in combination satisfy a single requirement. We present a validation of our approach consisting of a performance evaluation and the realization of a use case, both based on our implementation of the semantic policy matching algorithm. We furthermore show the advantages of our approach compared to existing related work.

No abstract

No abstract