This book constitutes the refereed proceedings of the 20th International Conference on Conceptual Modeling, ER 2001, held in Tokohama, Japan, in November 2001. The 45 revised full papers presented together with three keynote presentations were carefully reviewed and selected from a total of 197 submissions. The papers are organized in topical sections on spatial databases, spatio-temporal databases, XML, information modeling, database design, data integration, data warehouse, UML, conceptual models, systems design, method reengineering and video databases, workflows, web information systems, applications, and software engineering.

This book constitutes the refereed proceedings of the 20th International Conference on Conceptual Modeling, ER 2001, held in Tokohama, Japan, in November 2001. The 45 revised full papers presented together with three keynote presentations were carefully reviewed and selected from a total of 197 submissions. The papers are organized in topical sections on spatial databases, spatio-temporal databases, XML, information modeling, database design, data integration, data warehouse, UML, conceptual models, systems design, method reengineering and video databases, workflows, web information systems, applications, and software engineering.

The objective of the workshops associated with ER 2001, the 20th International Con- rence on Conceptual Modeling, was to give participants the opportunity to present and discuss emerging hot topics, thus adding new perspectives to conceptual modeling. This, the 20th ER conference, the ?rst of the 21st century, was also the ?rst one in Japan. The conference was held on November 27-30, 2001 at Yokohama National University with 192 participants from 31 countries. ER 2001 encompasses the entire spectrum of c- ceptual modeling, from theoretical aspects to implementations, including fundamentals, applications, and software engineering. In particular, ER 2001 emphasized e-business and reengineering. To meet this objective, we selected the following four topics and planned four international workshops: – International Workshop on Conceptual Modeling of Human/Organizational/Social Aspects of Manufacturing Activities (HUMACS 2001) Manufacturing enterprises have to confront a host of demands. The competitive climate, enhanced by communication and knowledge sharing, will require incr- singly rapid responses to market forces. Customer demands for higher quality, better services, and lower cost will force manufacturers to reach new levels of ?exibility and adaptability. Sophisticated customers will demand products customized to meet their needs. Industries have so far sought to cope with these challenges primarily through advances in traditional capital by installing more powerful hardware and software technology. Attention to the role of humans combined with organizational and social schemes in manufacturing has only been marginal. The workshop HUMACS 2001 aimed to challenge the relevance of this last point.

On behalf of the Organizing Committee, we would like to welcome you to the proccedings of the 23rd International Conference on Conceptual Modeling (ER 2004). This conference provided an international forum for technical discussion on conceptual modeling of information systems among researchers, developers and users. This was the third time that this conference was held in Asia; the?rst time was in Singapore in 1998 and the second time was in Yokohama, Japan in 2001. China is the third largest nation with the largest population in the world. Shanghai, the largest city in China and a great metropolis, famous in Asia and throughout the world, is therefore a most appropriate location to host this conference. This volume contains papers selected for presentation and includes the two keynote talks by Prof. Hector Garcia-Molina and Prof. Gerhard Weikum, and an invited talk by Dr. Xiao Ji. This volume also contains industrial papers and demo/poster papers. An additional volume contains papers from 6 workshops. The conference also featured three tutorials: (1) Web Change Management andDelta Mining: Opportunities andSolutions, by SanjayMadria, (2)A Survey of Data Quality Issues in Cooperative Information Systems, by Carlo Batini, and (3) Visual SQL - An ER-Based Introduction to Database Programming, by Bernhard Thalheim.