We present a declarative language for the construction of hypertext views on databases. The language is based on an object-oriented data model and a simple hypertext model with reference and inclusion links. A hypertext view specification consists in a collection of parameterized node schemes which specify how to construct node and link instances from the database contents. We show how this language can express different issues in hypertext view design. These include: the direct mapping of objects to nodes; the construction of complex nodes based on sets of objects; the representation of polymorphic sets of objects; and the representation of tree and graph structures. We have defined sublanguages corresponding to particular database models (relational, semantic, object-oriented) and implemented tools to generate Web views for these database models.
This paper presents a language and a system to construct a hypertextual view (a hyperview) of the content of a database. We first study different approaches to map database objects to hypertext components: tuple level mapping, tuple sets mapping, and associated tuples mapping. Then we present a declarative hyperview definition language which integrates these approaches. With this language one can specify for each node type and each link type how to construct it from the database contents. We also show how the semantic relationship represented in the database schema can be used to design the hypertext structure. A prototype translator has been implemented to generate a Worldwide Web (W3) hyperview of a relational database, the main components of this generation system are presented. We also show how the translation process can overcome some shortcoming of the W3 hypertext model.
The paper develops two synthetic measures at the HS-10 level to depict effective market access for a country receiving preferential access and applies these to the market access ASEAN members would receive following the implementation of an FTA with the EU. First, the measures show that current effective market access for ASEAN EBA members is cut in half by the preferences granted by the EU to countries that compete with these countries in the EU markets. Second, the measures show that about one-quarter of the preferential margin under the proposed FTA for EBA members would be lost as a result of preferential access granted to ASEAN GSP members. Third, disaggregated estimates of the restrictiveness of rules of origin confirm that rules are more restrictive for products with higher preferential margins and that ASEAN countries usually face tougher rules of origin in the EU because of the composition of their exports.
Une ontologie multi-points de vue est une ontologie dans laquelle chaque concept peut avoir plusieurs définitions différentes, chacune d'entre elles représentant un point de vue différent (selon le point de vue un concept peut également être situé à plusieurs emplacements différents dans la hiérarchie). Si beaucoup de travaux ont porté sur l'utilisation d'ontologies dans diverses applications, relativement peu a été écrit sur la construction manuelle d'ontologies et sur leur utilisation comme outil de référence (à la manière d'un dictionnaire) par des utilisateurs humains. Dans cet article, nous étudierons la création d'interfaces hypertextes qui permettent de naviguer dans une ontologie. La navigation est un moyen intéressant pour se familiariser avec un domaine, à la fois pour les utilisateurs finaux et pour les personnes participant à la construction ou à la mise à jour de l'ontologie elle-même. Nous chercherons entre autres à créer de nouveaux types de liens entre les concepts (c'est-à-dire des liens autres que les liens générique/spécifique ou que les rôles de la logique descriptive utilisée pour spécifier l'ontologie), par exemple des liens "calculés". On peut par exemple calculer des distances entre concepts; distances qui seront ensuite utilisées pour créer des liens entre concepts proches.
Using the same data, which could come from local databases or external sources such as the Web, virtual museum designers can build different hyperspaces. It is possible that visitors would find some of them more useful than others. Therefore, virtual museums designers should be equipped with a tool by which various hyperspaces for virtual museums can be easily designed and examined. In this paper, we view a virtual museum as a hypertext that consists of nodes and links and show that a database publishing tool called Lazy, which generates a hypertext view (i.e., derived hypertext) of a given database, can be used for designing virtual museums. The Lazy system consists of a declarative hypertext view specification language, a node schema compiler, and a node server that processes node requests. Since the language is purely declarative, it is fairly easy to construct and revise hyperspaces for a virtual museum. With this tool it becomes possible to adopt an iterative design methodology. Given a database for a virtual museum, we first construct a hypertext using the procedure (Falquet & al., 1999) called an initial structure. We then proceed to analyze the initial structure and examine possible refinement operations that can enhance the usability of the created hypertext. For that purpose, we use a simple graph-based analysis and we show kinds of analysis that can be done using the graph-based approach. Once the structure is refined using the refinement operations, we apply grammar-based formalism (Park, 1998) to the refined structure to see whether we can obtain a simpler grammar that can generate the same hyperspace. Our goal is to explore various analysis techniques on the hypertext and give insights into designing a good hyperspace using the analysis results.
Designing a terminological knowledge base consists in collecting terms and associating them to their definition. Our objective is to define a process model to support this design task in a collaborative work environment. The proposed concept model is based on terminological logic and the issue-based model IBIS. The terminological logic part is intended to formally express definitions and associate them to terms and points of view. The process model we define is based on a cyclic conflict resolution process. It includes a formal concept comparison operation, to highlight definition conflicts and their nature, and other operations (derivation, intersection, union, etc.) to solve the detected conflicts. The IBIS part of the model enable users to express and record issues, positions, arguments and endorsements that occur during conflict resolution.
