A schema-based P2P network to enable publish-subscribe for multimedia content in open hypermedia systems

Open Hypermedia Systems (OHS) aim to provide efficient dissemination, adaptation and integration of hyperlinked multimedia resources. Content available in Peer-to-Peer (P2P) networks could add significant value to OHS provided that challenges for efficient discovery and prompt delivery of rich and up-to-date content are successfully addressed. This paper proposes an architecture that enables the operation of OHS over a P2P overlay network of OHS servers based on semantic annotation of (a) peer OHS servers and of (b) multimedia resources that can be obtained through the link services of the OHS. The architecture provides efficient resource discovery. Semantic query-based subscriptions over this P2P network can enable access to up-to-date content, while caching at certain peers enables prompt delivery of multimedia content. Advanced query resolution techniques are employed to match different parts of subscription queries (subqueries). These subscriptions can be shared among different interested peers, thus increasing the efficiency of multimedia content dissemination

Hypermedia and the semantic web: a research agenda

Until recently, the Semantic Web was little more than a name for the next generation Web infrastructure as envisioned by its inventor, Tim Berners-Lee. Now, with the introduction of XML and RDF, and new developments such as RDF Schema and DAML+OIL, the Semantic Web is rapidly taking shape. In this paper, we first give an overview of the state-of-the-art in Semantic Web technology, the key relationships with traditional hypermedia research, and a comprehensive reference list to various sets of literature (Hypertext, Web and Semantic Web). The core of the paper presents a research agenda b

A Study of Information Fragment Association in Information Management and Retrieval Applications

As we strive to identify useful information sifting through the vast number of resources available to us, we often find that the desired information is residing in a small section within a larger body of content which does not necessarily contain similar information. This can make this Information Fragment difficult to find. A Web search engine may not provide a good ranking to a page of unrelated content if it contains only a very small yet invaluable piece of relevant information. This means that our processes often fail to bring together related Information Fragments. We can easily conceive of two Information Fragments which according to a scholar bear a strong association with each other, yet contain no common keywords enabling them to be collocated by a keyword search.This dissertation attempts to address this issue by determining the benefits of enhancing information management and retrieval applications by providing users with the capability of establishing and storing associations between Information Fragments. It estimates the extent to which the efficiency and quality of information retrieval can be improved if users are allowed to capture mental associations they form while reading Information Fragments and share these associations with others using a functional registry-based design. In order to test these benefits three subject groups were recruited and assigned tasks involving Information Fragments. The first two tasks compared the performance and usability of a mainstream social bookmarking tool with a tool enhanced with Information Fragment Association capabilities. The tests demonstrated that the use of Information Fragment Association offers significant advantages both in the efficiency of retrieval and user satisfaction. Analysis of the results of the third task demonstrated that a mainstream Web search engine performed poorly in collocating interrelated fragments when a query designed to retrieve the one of these fragments was submitted. The fourth task demonstrated that Information Fragment Association improves the precision and recall of searches performed on Information Fragment datasets.The results of this study indicate that mainstream information management and retrieval applications provide inadequate support for Information Fragment retrieval and that their enhancement with Information Fragment Association capabilities would be beneficial

Processing Structured Hypermedia - A Matter of Style

Vliet, J.C. van [Promotor]Eliens, A. [Copromotor

An agenda for open hypermedia research

The historical development of hypermedia systems can be characterized as a series of successive abstractions of functionality away from the "core " hypermedia server, often resulting in a new open layer in the hypermedia environment architecture. Recently, this trend of abstraction has been applied to the hypermedia server itself, replacing the notion of a single, closed hypermedia server with an open layer of structure servers. This newest development brings with it a new set of challenges and research issues for open hypermedia researchers. In this paper, we discuss these issues, review some of our collective applicable experience with contemporary open hypermedia systems and other work, and point out some of the more pressing and intriguing open questions that we feel are facing open hypermedia researchers today. We also examine the "split" in the current hypermedia research community between "system " and "domain " researchers and the still-present need for interoperability among systems, and discuss why any attempt to address the issues we discuss in this paper must account for these observations