Naming in OHP

Naming is a key issue in any distributed system. In particular, with the Open Hypermedia Systems Working Group's efforts towards openness and interoperability in Open Hypermedia Systems (OHS) resulting in the need for (globally) valid names for all types of resources the issue of naming has become increasingly important. In this position paper we examine the issues involved in naming and a naming proposal to be used within the Open Hypermedia Protocol (OHP)

Solent --- a Platform for Distributed Open Hypermedia Applications

Today's open hypermedia systems (OHS) provide middleware services for a range of hypertext applications. However, configuration and adaptation to specific applications' requirements is a tedious task. Research has been conducted into further splitting hypermedia middleware systems up into sets of interacting components that can be combined, extended and configured dynamically. These component-based open hypermedia systems (CB-OHS) allow for better adaptability, configurability and also interoperability amongst hypermedia middleware systems themselves. Described is the Solent component-based open hypermedia system. In particular, we focus on architecture, dynamic service discovery and invocation as well as the storage interface, which allows for storage and retrieval of arbitrary hierarchical structures encoded in XML

Abstract

Naming is a key issue in any distributed system. In particular, with the Open Hypermedia Systems Working Group's efforts towards openness and interoperability in Open Hypermedia Systems (OHS) resulting in the need for (globally) valid names for all types of resources the issue of naming has become increasingly important. In this position paper we examine the issues involved in naming and a present a proposal for naming to be used within th

A Generic Coordination Architecture as an Enabler for Mobile Collaborative Applications

Recent technological advances in hardware manufacturing and wireless communication systems result in a tremendous increase of heterogeneous computing elements involved in mobile and pervasive environments. Therefore, the complexity of systems supporting mobile collaboration is steadily increasing. To guarantee a certain level of service quality, coordination of this manifold of entities is required. Current approaches in pervasive computing usually address this demand inappropriately and consequently, inhere significant drawbacks when it comes to modularity, reusability, exchangeability, and extensibility of the implicit coordination mechanisms. This work proposes an explicit, generic two-layered coordination architecture which particularly aims at the specific characteristics of mobile and pervasive computing environments necessary for collaborative applications. This architecture comprises (i) the coordination media layer adhering to the decentralised space-based computing paradigm, and (ii) the coordination patterns layer proposing several problem-specific patterns. The idea is to provide a catalogue of reusable coordination patterns similar to the concept of software design patterns. 1

FOHM: A Fundamental Open Hypertext Model for Investigating Interoperability between Hypertext Domains

The Open Hypermedia Systems community has been largely concerned with interoperability between hypertext systems which share the same paradigm. It has evolved a component based framework for this purpose, in which specific but incompatible middleware components are designed for each hypertext domain, such as navigational hypertext, spatial hypertext or taxonomic hypertext. This paper investigates the common features of these domains and introduces FOHM, a Fundamental Open Hypertext Model, which defines a common data model and set of related operations that are applicable for all three domains. Using this layer the paper explores the possible semantics of linking between different hypertext domains, and shows that each can introduce features which benefit the other domains

OHP - Communicating between Hypermedia Aware Applications

A number of systems support hypertext functionality by storing links in link services; these links may then be superimposed on, or included into the document by the client browser. However, there is no standard protocol that allows client side tools to interoperate with link servers. The Open Hypermedia Systems (OHS) Community is therefore proposing a standard protocol called the Open Hypermedia Protocol (OHP) for client side applications to communicate with link servers for the purpose of storing, retrieving and navigating hypermedia objects. Adoption of this protocol would enable developers and researchers to re-use standard viewers including Web browsers and link servers within their systems

The ContentSpec Protocol: Providing Document Management Services for OHP

Users often face difficulties in accessing documents referenced by open hypermedia systems due to the different protocols employed. This is particularly a problem for OHP as it will often need to access documents in many varied hyperbase systems stores or other third party information repositories when navigating links. This position paper proposes a document management protocol, called the ContentSpec Protocol (CSP), for use in combination with the OHP, and with open hypermedia systems in general. This protocol would enable standardised access to documents in third party data stores, creating a wider information space for open hypermedia users to explore

A Market-Based Recommender System

We have designed, implemented, deployed and evaluated a large-scale agent-oriented information system that recommends relevant documents to users. Our recommender system is now being used across several European institutions. Its two key features are a modular design capable of accomodating multiple recommendation methods, and the use of a marketplace to select and rank the best recommendations for the user. As part of our evaluation, we have extensively simulated this marketplace in order to understand its dynamics and validate its suitability for a recommender system