Virtual Reality Tele-conferencing: Implementation and Experience

This paper describes the implementation of and early experiences with a virtual reality teleconferencing system called MASSIVE. This system includes a full realisation of the spatial model of interaction and its concepts of aura, awareness, focus, nimbus and adapters as was presented at ECSCW'93. This model supports users in interacting over ad-hoc combinations of audio, graphical and textual media through both 3-D and 2-D interfaces. Observations arising from the use of MASSIVE to support laboratory meetings are discussed; these include the need to support richer peripheral awareness, the need to improve the sensitivity of navigation, problems with lack of engagement between users, the need to support varying degrees of presence and problems arising from different perceptions of space between 2-D and 3-D users. Possible solutions to these problems are proposed. 1

A new sharpness measure based on Gaussian Lines And Edges

We measure the sharpness of natural (complex) images using Gaussian models. We first locate lines and edges in the image. We apply Gaussian derivatives at different scales to the lines and edges. This yields a response function, to which we can fit the response function of model lines and edges. We can thus estimate the width and amplitude of the line or edge. As measure of the sharpness we propose the 5 of the sigmas or the number of line/edge pixels with a sigma smaller than 1

Medium versus mechanism: Supporting collaboration through customisation

Abstract The study of cooperative work as a socially-situated activity has led to a focus on providing 'mechanisms ' that more closely resonate with existing work practice. In this paper we challenge this approach and suggest the flexibly organised nature of work is better supported when systems provide a 'medium ' which can be tailored to suit each participant's needs and organised around the detail of their work. This orientation towards 'medium ' rather than 'mechanism ' has consequences for cooperative system design, highlighting a need to allow participants to adapt details of policy currently embedded in the heart of the systems we build We describe an approach which allows users to perform such 'deep customisation ' through direct manipulation of user interface representation

Contact: Support for Distributed Cooperative Writing

Abstract: This paper presents a novel system to support the activities of distributed cooperative writing. The system builds upon the results from previous studies of cooperative work, and on a set of short focused studies of cooperative authoring to outline a framework and system to meet the requirements of cooperating authors. The system provides facilities to represent the decomposition of the writing task and assignment of responsibilities. In addition, a series of monitoring facilities is provided which allows authors to coordinate their activities in the construction of documents