Information modelling and knowledge bases have become hot topics not only in academic communities related to information systems and computer science but also in the business area where information technology is applied.

The 21st European-Japanese Conference on Information Modelling and Knowledge Bases (EJC2011) continues the series of events that originally started as a cooperation initiative between Japan and Finland already in the last half of the 1980's. In 1991 the geographical scope of these conferences expanded to cover the whole Europe and other countries as well.

The EJC conferences constitute a world-wide research forum for the exchange of scientific results and experiences achieved in computer science and related disciplines using innovative methods and approaches. A platform has been established drawing together researches and practitioners dealing with information modelling and knowledge bases. The main topics of EJC conferences target the variety of themes in information modelling, conceptual analysis, design and specification of information systems, multimedia information modelling, multimedia systems, ontology, software engineering, knowledge and process management, knowledge bases, cross-cultural communication and context modelling. We also aim at applying new progressive theories. To this end much attention is paid also to theoretical disciplines including cognitive science, artificial intelligence, logic, linguistics and analytical philosophy.

In order to achieve EJC targets, an international program committee selected 16 full papers and 9 short papers in a rigorous reviewing process from 36 submissions; additional 2 papers are based on panel sessions in the conference and 2 on invited presentations. The selected papers cover many areas of information modelling, theory of concepts, database semantics, knowledge representation, software engineering, WWW information management, context-based information retrieval, ontology, image databases, temporal and spatial databases, document data management, process management, cultural modelling and many others.

The conference could not be a success without a lot of effort of many people and organizations.

In the Program Committee, 29 reputable researchers devoted a lot of effort to the review process selecting the best papers and creating the EJC2010 program. We are very grateful to them. Professor Yasushi Kiyoki and Professor Takehiro Tokuda were acting as co-chairs of the program committee. Dr. Naofumi Yoshida in Program Coordination Team was managing the review process and the conference program. Dr. Jaak Henno and his colleagues were managing the conference venue and the local arrangement. Professor Hannu Jaakkola took care of general organizational things necessary for annually running the conference series and, moreover, of arranging the conference proceedings in the form of a book to be printed by IOS Press Amsterdam. We gratefully appreciate the efforts of all the supporters.

We believe that the conference will be productive and fruitful in the advance of research and application of information modelling and knowledge bases.

The Editors

Jaak Henno

Yasushi Kiyoki

Takehiro Tokuda

Hannu Jaakkola

Naofumi Yoshida