Reasoning & Querying – State of the Art

Various query languages for Web and Semantic Web data, both for practical use and as an area of research in the scientific community, have emerged in recent years. At the same time, the broad adoption of the internet where keyword search is used in many applications, e.g. search engines, has familiarized casual users with using keyword queries to retrieve information on the internet. Unlike this easy-to-use querying, traditional query languages require knowledge of the language itself as well as of the data to be queried. Keyword-based query languages for XML and RDF bridge the gap between the two, aiming at enabling simple querying of semi-structured data, which is relevant e.g. in the context of the emerging Semantic Web. This article presents an overview of the field of keyword querying for XML and RDF

Optimized trusted information sharing

As the digital world expands the building of trust and the retention of privacy in information sharing becomes paramount. A major impediment to information sharing is a lack of trust between the parties, based on security and privacy concerns, as well as information asymmetry. Several technological solutions have been proposed to solve this problem, including our\u27s: a trusted enclave with a Continuous Compliance Assurance (CCA) mechanism. Of the work surrounding these proposed solutions, no attention has been directed toward studying the issues of performance surrounding processing of this nature. Studies have shown that ignoring the performance of a system can lead to ineffectiveness (i.e. disabling certain features), and can be severely detrimental to system adoption.;To ensure that our trusted enclave and CCA mechanism are viable solutions to the trusted information sharing problem, we have built a prototype CCA mechanism and a test bed. The test bed has allowed us to identify problem areas within our prototype. One such area is compliance verification, which utilizes the XPath language in order to test XML encoded information for compliance to regulatory and corporate policies. The compliance verification problem can be described as the answering of multiple queries over a single XML document. We proposed and tested multiple state-of-the-art algorithmic as well as system-based improvements to XPath evaluation, in order to better the overall performance of this aspect of our system. We integrated each of the improvements into our prototype mechanism and have observed the results. Our experiments have taught us much about the problem of compliance verification, and has led us in new directions as we continue to search for a solution

Web-oriented Event Processing

How can the Web be made situation-aware? Event processing is a suitable technology for gaining the necessary real-time results. The Web, however, has many users and many application domains. Thus, we developed multi-schema friendly data models allowing the re-use and mix from diverse users and application domains. Furthermore, our methods describe protocols to exchange events on the Web, algorithms to execute the language and to calculate access rights