Y. Ishikawa and H. Kitagawa : "Source Description-Based Approach for the Modeling of Spatial Information Integration", Proc. 20th International Conference on Conceptual Modeling (ER 2001), Vol. 2224 of Lecture Notes in Computer Science, pp. 41-55, Yokohama, Japan, November 2001
Y. Ishikawa, G. Ryu, and H. Kitagawa : "Integration of Spatial Information Sources Based on Source Description Framework (poster)", Proc. 7th International Conference on Database Systems for Advanced Applications (DASFAA 2001), pp. 160-161, Hong Kong, April 2001
Y. Ishikawa, H. Kitagawa, and T. Kawashima : "Continual Neighborhood Tracking for Moving Objects Using Adaptive Distances", Proc. International Database Engineering and Application Symposium (IDEAS'02), pp. 54-63, Edmonton, Canada, July 2002
Y. Ishikawa, Y. Tsukamoto, and H. Kitagawa : "Implementation and Evaluation of an Adaptive Neighborhood Information Retrieval System for Mobile Users", Proc. 3rd International Workshop on Web and Wireless Geographic Information Systems (W2GIS), pp. 25-33 , Roma, Italy, December 2003
Y. Ishikawa, Y. Tsukamoto, and H. Kitagawa : "Exracting Mobility Statistics from Indexed Spatio-Temporal Databases", Proc. 2nd Workshop on Spatio-Temporal Database Management (STDBM'04), pp. 9-16, Toronto, Canada, August 2004