We are pleased to bring you this special issue of Data and Knowledge Engineering based upon the 19th International Conference on Conceptual Modeling (ER2000), which was held on 9ยฑ12 October 2000 in Salt Lake City, Utah, USA. Continuing in its long tradition of attracting the leading researchers and practitioners in advanced information systems design and implementation, the conference provided a forum for presenting and discussing current research and applications in which the major emphasis was on conceptual modeling. Despite this emphasis on conceptual modeling, the conference also addressed other important, emerging topics resulting from recent technological advances. The conference itself consisted of both research and industrial paper sessions, invited talks and tutorials by leading specialists, as well as discussion panels.
This special issue includes four papers selected among the best ones by the Program Committee and that were considered representative to the types and diversity of research presented at the conference. Each one of these papers is an extended and revised version of the conference original paper and went through a rigorous reviewing process, before being accepted for inclusion in this special issue.
The ยฎrst paper, CPI: Constraint-preserving inlining algorithm for mapping XML DTD to relational schema by Dongwon Lee and Wesley W. Chu, captured the best paper award at the conference. It presents an algorithm to transform an XML Document Type Deยฎnition (DTD) into a relational schema. This algorithm is an improvement over existing ones in that it can capture semantic knowledge hidden in the DTD to ensure a correct relational schema. The semantic knowledge is captured during the transformation and is represented as semantic constraints in relational database terms.
The second paper, ROVER: ยฏexible yet consistent evolution of relationships by Kajal T. Claypool, Elke A. Rundensteiner, and George T. Heineman, views relationships as a very important concept in object-oriented modeling, but one that has not been dealt with suciently. The authors propose a ยฏexible schema evolution framework that allows a user to deยฎne and extend relationship transformations. This framework embeds a set of basic evolution primitives for relationships as well as a compound set of changes that can be applied to them. The result is a solution that provides for consistent evolution of relationships while supporting extensibility for user-deยฎned evolution operations.
In the third paper, Supporting ontological analysis of taxonomic relationships by Christopher Welty and Nicola Guarino, the authors examine taxonomies as an important part of conceptual Data & Knowledge Engineering 39 (2001) 1ยฑ2 www.elsevier.com/locate/datak