The advantages of service-oriented architecture for information systems development have increased its popularity and improved service availability over the Internet. In order to maintain its sustainability and prevent users from exploiting free services, a service-oriented market mechanism should be introduced to regulate the market. However, this issue has not been well addressed in the community. In this work, we propose core-based agents that can collect information from service-oriented markets to convince service providers and consumers to form a coalition based on the core concept solution from game theory. With the introduction of the agent to the service-oriented market, a number of multiple core markets can be merged into a virtual market with a unique core which satisfies the requirements of stability and efficiency. An example of a travel agent web service, which is a composite web service, will be used to illustrate the roles of the agents in this paper.

We present two studies that have advanced the design of brain-body interfaces for use in the rehabilitation of individuals with severe neurological impairment due to traumatic brain injury. We first developed and evaluated an adaptive cursor acceleration algorithm based on screen areas. This improved the initial design, but was too inflexible to let users make the most of their highly varied abilities. Only some individuals were well served by this adaptive interface. We therefore developed and evaluated an approach based on personalized tile layouts. The rationales for both designs are presented, along with details of their implementation. Evaluation studies for each are reported, which show that we have extended the user population who can use our interfaces relative to previous studies. We have also extended the usable functionality for some of our user group. We thus claim that personalized tiling with discrete acceleration has allowed us to extend the usable functionality of brain-body interfaces to a wider population with traumatic brain injury, thus creating new options for neurorehabiliation.

Brain–body interfaces (BBIs) have been shown through a number of studies to be useful assistive technology devices for recreation and communication. However, severely motor impaired persons with no other means of interacting with their environment have had difficulties using the standard communication software for the Cyberlink, the commercially available BBI device which we used in our studies. We have therefore developed a simple Yes/No program, drawing on a range of design and evaluation approaches from Human–Computer Interaction research. This paper presents the first extensive evaluation of this program. Its evaluation combines formal assessments with observations from users, carers and technology and mental health professionals who are involved in the research. Our conclusions are that the performance of severely impaired individuals cannot be readily separated from that of novice unimpaired users, that worthwhile results can be achieved with the Yes/No program, but at the moment the cost of using a Cyberlink is too high for most assistive technology contexts. However, for severely impaired individuals, Cyberlink use may be the only form of recreation and communication available to them, and thus the current limitations of the technology are acceptable for this user population.

We summarise the results of the first studies to investigate the Cyberlink brain body interface as an assistive technology. Three phases of studies and a contextual inquiry were performed with a range of users. A focus group was formed from brain-injured users with locked-in syndrome who have no other method of communication or control of a computer than the Cyberlink. Versions of a Yes/No program were then created to allow communication and have achieved some success with the focus group. The purpose of this paper is to discuss how this program has been improved and what steps need to be taken to create communication programs for persons with severe motor impairment. As a result of our experiences, we have been able to develop a set of design guidelines for brain-body interface operated Yes/No programs. These are presented and justified on the basis of our experiences. We also raise some general issues for assistive technologies of this nature.

Abstract Nowadays, we are witnessing the development of new information-seeking environments and applications such as hypermedia digital libraries. Information Retrieval (IR) is increasingly embedded in these environments and plays a cornerstone role. However, in hypermedia digital libraries IR is a part of a large and complex user-centred information-seeking environment. In particular, information seeking is also possible using non-analytical, opportunistic and intuitive browsing strategies. This paper discusses the particular evaluation problems posed by these current developments. Current methods based on Recall (R) and Precision (P) for evaluating IR are discussed, and their suitability for evaluating the performance of hypermedia digital libraries is examined. We argue that these evaluation methods cannot be directly applied, mainly because they do not measure the effectiveness of browsing strategies; the underlying notion of relevance ignores the highly interconnected nature of hypermedia information and misses the reality of how information seekers work in these environments. Therefore, we propose a new quantitative evaluation methodology, based on the structural analysis of hypermedia networks and the navigational and search state patterns of information seekers. Although the proposed methodology retains some of the characteristics (and criticisms) of R and P evaluations, it could be more suitable than them for measuring the performance of information-seeking environments where information seekers can utilize arbitrary mixtures of browsing and query-based searching strategies.

The design and implementation of network management systems is one of the first application areas in which the use of object-orientation was applied on a wide scale. A major reason is that resources that need to be managed in computer networks seem to map naturally into objects. However, network management systems which can deal with heterogeneous networks are very complex systems, and it is easy to end up with a large number of poorly designed objects instead of an integrated and effective system. This paper evaluates the weaknesses of some of the common object-oriented analysis techniques, and provide the outline of a methodology which will avoid some of these pitfalls in the design and implementation of an X.25 network management system based on an object-oriented database management system (OODBMS).

The primary goal of this paper is to present a generic framework for complex medical expert system inference. The rapid prototype of an expert system can be achieved by to three system components. They are namely the object static component, presentation components and inference components. This idea is borrowed from the Model View and Control (MVC) approach. The inter-relationship between these system components are elaborated in this paper. We use PC-Kappa as our system development environment which supports an expert system development facility as well as object-oriented programming. An extension of full object-oriented techniques that is not supported by the Kappa-PC is also presented in this paper for object-oriented expert system construction.>