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Publication Constructing programs or processes(Working Paper, Department of Computer Science, University of Waikato, 2005-12) Reeves, Steve; Streader, DavidWe define interacting sequential programs, motivated originally by constructivist considerations. We use them to investigate notions of implementation and determinism. Process algebras do not define what can be implemented and what cannot. As we demonstrate it is problematic to do so on the set of all processes. Guided by constructivist notions we have constructed interacting sequential programs which we claim can be readily implemented and are a subset of processes.Publication StoneD: A bridge between Greenstone and DSpace(Working Paper, University of Waikato, Department of Computer Science, 2005-04) Witten, Ian H.; Bainbridge, David; Tansley, Robert; Huang, Chi-Yu; Don, Katherine J.Greenstone and DSpace are widely-used software systems for digital libraries, and prospective users sometimes wonder which one to adopt. In fact, the aims of the two are very different, although their domains of application do overlap. This paper describes the systems and identifies their similarities and differences. We also present StoneD, a stone bridge between the production versions of Greenstone and DSpace that allows users of either system to easily migrate to the other, or continue with a combination of both. This bridge eliminates the risk of finding oneself locked in to an inappropriate choice of system. We also discuss other possible opportunities for combining the advantages of the two, to the benefit of the user communities of both systems.Publication ApproXFILTER - an approximative XML filter(Working Paper, Department of Computer Science, University of Waikato, 2005-01-01) Michel, Yann-Rudolf; Hinze, AnnikaPublish/subscribe systems filter published documents and inform their subscribers about documents matching their interests. Recent systems have focussed on documents or messages sent in XML format. Subscribers have to be familiar with the underlying XML format to create meaningful subscriptions. A service might support several providers with slightly differing formats, e.g., several publishers of books. This makes the definition of a successful subscription almost impossible. We propose the use of an approximative language for subscriptions.We introduce the design our ApproXFILTER algorithm for approximative filtering in a pub/sub system. We present the results of our analysis of a prototypical implementation.Publication Design and implementation of a filter engine for semantic web documents(Working Paper, Department of Computer Science, University of Waikato, 2005-01-01) Kozuka, Takanori; Hinze, AnnikaThis report describes our project that addresses the challenge of changes in the semantic web. Some studies have already been done for the so-called adaptive semantic web, such as applying inferring rules. In this study, we apply the technology of Event Notification System (ENS). Treating changes as events, we developed a notification system for such events.Publication Investigating the memory requirements for publish/subscribe filtering algorithms(Working Paper, Department of Computer Science, 2005-01-01) Bittner, Sven; Hinze, AnnikaVarious filtering algorithms for publish/subscribe systems have been proposed. One distinguishing characteristic is their internal representation of Boolean subscriptions: They either require conversions to disjunctive normal forms (canonical approaches) or are directly exploited in event filtering (non-canonical approaches). In this paper, we present a detailed analysis and comparison of the memory requirements of canonical and non-canonical filtering algorithms. This includes a theoretical analysis of space usages as well as a verification of our theoretical results by an evaluation of a practical implementation. This practical analysis also considers time (filter) efficiency, which is the other important quality measure of filtering algorithms. By correlating the results of space and time efficiency, we conclude when to use non-canonical and canonical approaches.Publication A distributed directory service for Greenstone(Working Paper, Department of Computer Science, University of Waikato, 2005-01-01) Buchanan, George; Hinze, AnnikaGreenstone is a software for creating and maintaining distributed digital library collections. It provides a sophisticated federation mechanism for the collections. In order to support alerting notification about changes in the distributed collections, we propose a distributed directory service for the management of the distributed Greenstone installations. The Greenstone directory service (GDS) acts on top of the distributed Greenstone structure for the management of collections. This paper describes both, the initial distributed Greenstone structure and the distributed directory service.Publication Advanced recommendations in a mobile tourist information system(Working Paper, Department of Computer Science, University of Waikato, 2005-01-01) Junmanee, Saijai; Hinze, AnnikaAn advanced tourist information provider system delivers information regarding sights and events on their users' travel route. In order to give sophisticated personalized information about tourist attractions to their users, the system is required to consider base data which are user preferences defined in their user profiles, user context, sights context, user travel history as well as their feedback given to the sighs they have visited. In addition to sights information, recommendation on sights to the user could also be provided. This project concentrates on combinations of knowledge on recommendation systems and base information given by the users to build a recommendation component in the Tourist Information Provider or TIP system. To accomplish our goal, we not only examine several tourist information systems but also conduct the investigation on recommendation systems. We propose a number of approaches for advanced recommendation models in a tourist information system and select a subset of these for implementation to prove the concept.Publication Stepwise refinement of processes(Working Paper, 2005-01-01) Reeves, Steve; Streader, DavidIndustry is looking to create a market in reliable "plug-and-play" components. To model components in a modular style it would be useful to combine event-based and state-based reasoning. One of the first steps in building an event-based model is to decide upon a set of atomic actions. This choice will depend on the formalism used, and may restrict in quite unexpected ways what we are able to formalise. In this paper we illustrate some limits to developing real world processes using existing formalisms, and we define a new notion of refinement, vertical refinement, which addresses some of these limitations. We show that using vertical refinement we can rewrite specification into a different formalism, allowing us to move between handshake processes, broadcast processes and abstract data types.Publication Towards a TIP 3.0 service-oriented architecture: Interaction design.(Working Paper, University of Waikato, 2005-01-01) Hinze, Annika; Malik, Petra; Malik, RobiThis paper describes our experience when applying formal methods in the design of the tourist information system TIP, which presents context-sensitive information to mobile users with small screen devices. The dynamics of this system are very complex and pose several challenges, firstly because of the sophisticated interaction of several applications on a small screen device and the user, and secondly because of the need for communication with highly asynchronous event-based information systems. UML sequence diagrams have been used to capture the requirements and possible interactions of the system. In a second step, a formal model has been created using discrete event systems, in order to thoroughly understand and analyse the dynamics of the system. By verifying general properties of the formal model, several conceptual difficulties have been revealed in very early stages of the design process, considerably speeding up the development. This work shows the limitations of typical methods for interaction design when applied to mobile systems using small screen devices and proposes an alternative approach using discrete event systems.