An Open Framework for Integrating Widely Distributed Hypermedia Resources

The success of the WWW has served as an illustration of how hypermedia functionality can enhance access to large amounts of distributed information. However, the WWW and many other distributed hypermedia systems offer very simple forms of hypermedia functionality which are not easily applied to existing applications and data formats, and cannot easily incorporate alternative functions which would aid hypermedia navigation to and from existing documents that have not been developed with hypermedia access in mind. This paper describes the extension to a distributed environment of the open hypermedia functionality of the Microcosm system, which is designed to support the provision of hypermedia access to a wide range of source material and application, and to offer straightforward extension of the system to incorporate new forms of information access

COSMOS-7: Video-oriented MPEG-7 scheme for modelling and filtering of semantic content

MPEG-7 prescribes a format for semantic content models for multimedia to ensure interoperability across a multitude of platforms and application domains. However, the standard leaves it open as to how the models should be used and how their content should be filtered. Filtering is a technique used to retrieve only content relevant to user requirements, thereby reducing the necessary content-sifting effort of the user. This paper proposes an MPEG-7 scheme that can be deployed for semantic content modelling and filtering of digital video. The proposed scheme, COSMOS-7, produces rich and multi-faceted semantic content models and supports a content-based filtering approach that only analyses content relating directly to the preferred content requirements of the user

A VISUAL DESIGN METHOD AND ITS APPLICATION TO HIGH RELIABILITY HYPERMEDIA SYSTEMS

This work addresses the problem of the production of hypermedia documentation for applications that require high reliability, particularly technical documentation in safety critical industries. One requirement of this application area is for the availability of a task-based organisation, which can guide and monitor such activities as maintenance and repair. In safety critical applications there must be some guarantee that such sequences are correctly presented. Conventional structuring and design methods for hypermedia systems do not allow such guarantees to be made. A formal design method that is based on a process algebra is proposed as a solution to this problem. Design methods of this kind need to be accessible to information designers. This is achieved by use of a technique already familiar to them: the storyboard. By development of a storyboard notation that is syntactically equivalent to a process algebra a bridge is made between information design and computer science, allowing formal analysis and refinement of the specification drafted by information designers. Process algebras produce imperative structures that do not map easily into the declarative formats used for some hypermedia systems, but can be translated into concurrent programs. This translation process, into a language developed by the author, called ClassiC, is illustrated and the properties that make ClassiC a suitable implementation target discussed. Other possible implementation targets are evaluated, and a comparative illustration given of translation into another likely target, Java

London SynEx Demonstrator Site: Impact Assessment Report

The key ingredients of the SynEx-UCL software components are: 1. A comprehensive and federated electronic healthcare record that can be used to reference or to store all of the necessary healthcare information acquired from a diverse range of clinical databases and patient-held devices. 2. A directory service component to provide a core persons demographic database to search for and authenticate staff users of the system and to anchor patient identification and connection to their federated healthcare record. 3. A clinical record schema management tool (Object Dictionary Client) that enables clinicians or engineers to define and export the data sets mapping to individual feeder systems. 4. An expansible set of clinical management algorithms that provide prompts to the patient or clinician to assist in the management of patient care. CHIME has built up over a decade of experience within Europe on the requirements and information models that are needed to underpin comprehensive multiprofessional electronic healthcare records. The resulting architecture models have influenced new European standards in this area, and CHIME has designed and built prototype EHCR components based on these models. The demonstrator systems described here utilise a directory service and object-oriented engineering approach, and support the secure, mobile and distributed access to federated healthcare records via web-based services. The design and implementation of these software components has been founded on a thorough analysis of the clinical, technical and ethico-legal requirements for comprehensive EHCR systems, published through previous project deliverables and in future planned papers. The clinical demonstrator site described in this report has provided the solid basis from which to establish "proof of concept" verification of the design approach, and a valuable opportunity to install, test and evaluate the results of the component engineering undertaken during the EC funded project. Inevitably, a number of practical implementation and deployment obstacles have been overcome through this journey, each of those having contributed to the time taken to deliver the components but also to the richness of the end products. UCL is fortunate that the Whittington Hospital, and the department of cardiovascular medicine in particular, is committed to a long-term vision built around this work. That vision, outlined within this report, is shared by the Camden and Islington Health Authority and by many other purchaser and provider organisations in the area, and by a number of industrial parties. They are collectively determined to support the Demonstrator Site as an ongoing project well beyond the life of the EC SynEx Project. This report, although a final report as far as the EC project is concerned, is really a description of the first phase in establishing a centre of healthcare excellence. New EC Fifth Framework project funding has already been approved to enable new and innovative technology solutions to be added to the work already established in north London

Design of Participatory Virtual Reality System for visualizing an intelligent adaptive cyberspace

The concept of 'Virtual Intelligence' is proposed as an intelligent adaptive interaction between the simulated 3-D dynamic environment and the 3-D dynamic virtual image of the participant in the cyberspace created by a virtual reality system. A system design for such interaction is realised utilising only a stereoscopic optical head-mounted LCD display with an ultrasonic head tracker, a pair of gesture-controlled fibre optic gloves and, a speech recogni(ion and synthesiser device, which are all connected to a Pentium computer. A 3-D dynamic environment is created by physically-based modelling and rendering in real-time and modification of existing object description files by afractals-based Morph software. It is supported by an extensive library of audio and video functions, and functions characterising the dynamics of various objects. The multimedia database files so created are retrieved or manipulated by intelligent hypermedia navigation and intelligent integration with existing information. Speech commands control the dynamics of the environment and the corresponding multimedia databases. The concept of a virtual camera developed by ZeIter as well as Thalmann and Thalmann, as automated by Noma and Okada, can be applied for dynamically relating the orientation and actions of the virtual image of the participant with respect to the simulated environment. Utilising the fibre optic gloves, gesture-based commands are given by the participant for controlling his 3-D virtual image using a gesture language. Optimal estimation methods and dataflow techniques enable synchronisation between the commands of the participant expressed through the gesture language and his 3-D dynamic virtual image. Utilising a framework, developed earlier by the author, for adaptive computational control of distribute multimedia systems, the data access required for the environment as well as the virtual image of the participant can be endowed with adaptive capability

Bounding inconsistency using a novel threshold metric for dead reckoning update packet generation

Human-to-human interaction across distributed applications requires that sufficient consistency be maintained among participants in the face of network characteristics such as latency and limited bandwidth. The level of inconsistency arising from the network is proportional to the network delay, and thus a function of bandwidth consumption. Distributed simulation has often used a bandwidth reduction technique known as dead reckoning that combines approximation and estimation in the communication of entity movement to reduce network traffic, and thus improve consistency. However, unless carefully tuned to application and network characteristics, such an approach can introduce more inconsistency than it avoids. The key tuning metric is the distance threshold. This paper questions the suitability of the standard distance threshold as a metric for use in the dead reckoning scheme. Using a model relating entity path curvature and inconsistency, a major performance related limitation of the distance threshold technique is highlighted. We then propose an alternative time—space threshold criterion. The time—space threshold is demonstrated, through simulation, to perform better for low curvature movement. However, it too has a limitation. Based on this, we further propose a novel hybrid scheme. Through simulation and live trials, this scheme is shown to perform well across a range of curvature values, and places bounds on both the spatial and absolute inconsistency arising from dead reckoning

A Survey of Quality of Service in Mobile Computing Environments

Accepted versio