To address societal issues such as sustainable development, geoscience knowledge must be transformed from its conventional packaging. A holistic approach to this transformation requires that (1) geo-information be used to develop indicators such as mineral potential, material availability, groundwater capacity, etc., and that (2) the indicators are combined with socio-economic factors to guide generation of future scenarios for land use, population, urban growth, etc. In this paper we discuss the architecture of a prototype system designed to support these two activities. The system consists of a geoscientific data and knowledge repository that is loosely linked with a future scenario modeling tool (QuestTM). The repository supplies transformed information to the tool, and also provides explanations for the input variables and output results. An example implementation, Georgia Basin Digital Library, is also presented.

In this paper we describe a web application, called Pathways-Phoenix (PX), that facilitates collaboration between scientists, planners, and the public. PX leverages open geospatial standards and technologies for information delivery, and enables users to deliberate about the informa- tion in custom designed projects. To demonstrate its re-us- ability and effectiveness, PX is being tested in Canada and South America by a variety of geoscience agencies.

Digital libraries extend traditional library tools, collections, and metaphors in new and sometimes radical directions. Geoscience information, traditionally found in libraries in the form of maps, reports, books, and journal articles, can potentially gain enormous benefits from digital interfaces that allow geospatial information to be effectively searched and displayed in context. However, to many users of such a collection, the concepts within geoscience represent a barrier to use and understanding. The Georgia Basin Digital Library (GBDL) Project examines community-based decision support for sustainable development, using digital geoscience information as a fundamental component. The context and relevance of geoscientific and other information in the GBDL is explained and represented through the use of semistructured representations based on architectural pattern languages, where a web of connected concepts are each contextualized using storytelling with supporting graphics. The GBDL allows multiple coexisting pattern networks, so that multiple perspectives on an idea, a situation, or a region are possible and in fact preferable. The GBDL interface makes use of geographic information systems (GIS) components to show maps, such that the point of engagement for a user might alternatively be a story, a map, a photo, or a text heading. Linking the mapping component directly to the pattern framework allows for community-level contextualization of ideas and stories. For geoscientists, the ideas in the GBDL are relevant both as novel approaches to sharing geoscience information with the public and as approaches that can be applied to specialized scientific discourse in the future. As the Web evolves, geoscience information systems and communication must evolve along with it; the GBDL shows one such evolutionary pathway.

The design of Web-based digital libraries for thematic education, concept exploration, and community decision support represents a fundamental challenge in cybercartography. The incorporation of ideas from knowledge representation, education theory and practice, geomatics, cartography, and hypermedia into a consistent and usable suite of tools represents a challenge to both the conceptual architect and the system engineer. The conceptual architecture is hampered by the radically different interface metaphors each of these component approaches embody. The technical architecture is hampered by contrasting and often incompatible system architecture requirements for operation in a Web browser, and by the emphasis on ephemeral trends and approaches in the Web design community. A workable compromise requires balancing the two sets of requirements in a flexible way that honors the audience's core needs. The Georgia Basin Digital Library (GBDL), which supports sustainable development education, community development, and a rich interaction between social and scientific modes of understanding, attempts to accomplish this balance by using interface techniques that directly expose concept semantics and interconcept relationships to users. In GBEx-plorer, the test implementation for GBDL, cartographic and hypermedia tools are driven by a concept-network interface element, although in principle any of the three interface elements can be used for direct engagement. Associated online community support tools provide the ability for users to directly add to the digital library knowledge base at both the information asset and community atlas site-of-interest level. Ongoing research examines two-dimensional versus three-dimensional modes of interaction, supporting technology from artificial intelligence and geomatics, and especially the social impact and role of the digital library.

A method to make a coronary artery segment of interest appear stationary when viewing a sequence of angiographic images is proposed. The purpose of this method is to facilitate the assessment of lesions caused by coronary artery disease by improving detectability. A description of the stabilization algorithm based on template matching is given. Stabilization was performed on 41 clinical coronary angiograms exhibiting various stenoses and was successful in 39/41 cases. A quantitative analysis of stabilization errors was performed by introducing simulated moving vessels of decreasing contrast into sequences of clinical images.

We consider a supply function equilibrium (SFE) model of interaction in an electricity market. We assume a linear demand function and consider a competitive fringe and several strategic players having capacity limits and affine marginal costs. The choice of SFE over Cournot equilibrium and other models and the choice of affine marginal costs is reviewed in the context of the existing literature. We assume that bid rules allow affine or piecewise affine non-decreasing supply functions by firms and extend results of Green and Rudkevitch concerning the linear SFE solution. An incentive compatibility result is proved. We also find that a piecewise affine SFE can be found easily for the case where there are non-negativity limits on generation. Upper capacity limits, however, pose problems and we propose an ad hoc approach. We apply the analysis to the England and Wales electricity market, considering the 1996 and 1999 divestitures. The piecewise affine SFE solutions generally provide better matches to the empirical data than previous analysis.

Le Projet de biibliotheque numerique du bassin de Georgie vise a fournir un milieu favorable a la sensibilisation et a la comprehension des enjeux de durabilite. Cet article resume l'approche conceptuelle que nous avons adoptee pour interconnecter les systemes d'information geographique sur le Web, la representation des connaissances, la cartographie par les communautes et la participation du public afin de mieux sensibiliser, pour cette region de la Colombie-Britannique, a la durabilite environnementale, economique et sociale. En outre, on decrit la fonctionnalite d'une application Web, le GBExplorer, qui a ete concue afin de demontrer la viabilite de la transmission de visions communes et de perspectives de durabilite regionale et locale et d'encourager les connaissances de la collectivite et des specialistes a contribuer a un dialogue sur l'etat actuel et futur de la region. Le travail futur portera sur l'enrichissement des representations entre le GBExplorer et le paysage au moyen de techniques supplementaires comme la visualisation et le developpement d'ontologies de domaines en vue de structurer et de representer de facon explicite les concepts qui permettront d'appuyer la sensibilisation et le renforcement des connaissances.

We consider a supply function equilibrium (SFE) model of interaction in an electricity market. We assume a linear demand function and consider a competitive fringe and several strategic players all having capacity limits and affine marginal costs. The choice of SFE over Cournot equilibrium and the choice of affine marginal costs is reviewed in the context of the existing literature. We assume that bid rules allow affine or piecewise affine non-decreasing supply functions and extend results of Green and Rudkevitch concerning the linear SFE solution. An incentive compatibility result is proved. We also find that a piecewise affine SFE can be found easily for the case where there are non-negativity limits on generation. Upper capacity limits, however, pose problems and we propose an ad hoc approach. We apply the analysis to the England and Wales electricity market, considering the 1996 and 1999 divestitures. The piecewise affine SFE solutions generally provide better matches to the empirical data than previous analysis.

We consider a supply function equilibrium (SFE) model of interaction in an electricitymarket. We assume a linear demand function and consider a competitive fringe andseveral strategic players all having capacity limits and affine marginal costs. The choiceof SFE over Cournot equilibrium and the choice of affine marginal costs is reviewed inthe context of the existing literature.We assume that bid rules allow affine or piecewise affine non-decreasing supplyfunctions and extend results of...