The bar derived category of a curved dg algebra

Curved A-infinity algebras appear in nature as deformations of dg algebras. We develop the basic theory of curved A-infinity algebras and, in particular, curved dg algebras. We investigate their link with a suitable class of dg coalgebras via the bar construction and produce Quillen model structures on their module categories. We define the analogue of the relative derived category for a curved dg algebra.Comment: 38 pages, with figures, corrected typos. To appear in the Journal of Pure and Applied Algebr

from e-Heritage systems to Interpretive Archaeology Systems.

The principal purpose of this paper is to examine which research approaches are best suited for determining the requirements of the next generation of interactive interpretation support systems for cultural heritage site. We are optimistic that such systems if properly designed to exploit the potential of advanced information and communication technologies (ICTs), can not only meet, but even exceed visitor-user expectations. The research framework proposed to achieve this ideal integrates insights from both Interpretive Archaeology and interpretive IS research. We call the application of ICT’s in systems for communicating cultural heritage information “e-Heritage Systems or e-HS. We define “Interpretive Archaeology Systems”(IAS) as a subclass of e-HS, the design of which is informed by hermeneutics and phenomenology, Therefore, the principal purpose of the paper is to promote a shift from e-HS to IAS. To illustrate the fruitfulness of our preferred approach for IAS requirements identification, we derive a set of criteria from our research philosophy and apply them to the evaluation of an existing e-HS: the ARCHEOGUIDE in Olympia.Information systems; Cultural heritage; Phenomenology; Interpretive Information Systems Research; Interpretive Archaeology; Hermeneutics; Interpretive Archaeology Systems;

Augmented reality meeting table: a novel multi-user interface for architectural design

Immersive virtual environments have received widespread attention as providing possible replacements for the media and systems that designers traditionally use, as well as, more generally, in providing support for collaborative work. Relatively little attention has been given to date however to the problem of how to merge immersive virtual environments into real world work settings, and so to add to the media at the disposal of the designer and the design team, rather than to replace it. In this paper we report on a research project in which optical see-through augmented reality displays have been developed together with prototype decision support software for architectural and urban design. We suggest that a critical characteristic of multi user augmented reality is its ability to generate visualisations from a first person perspective in which the scale of rendition of the design model follows many of the conventions that designers are used to. Different scales of model appear to allow designers to focus on different aspects of the design under consideration. Augmenting the scene with simulations of pedestrian movement appears to assist both in scale recognition, and in moving from a first person to a third person understanding of the design. This research project is funded by the European Commission IST program (IST-2000-28559)