GIS'04 - Session 3 - Data Modeling and Security A new approach for a topographic feature-based characterization of digital elevation data Eric Saux Remy Thibaud Ki-Joune Li Minhwan Kim An Authorization Model for Geographical Maps Alberto Belussi Elisa Bertino Barbara Catania Maria Luisa Damiani Andrea Nucita Time-dependent affine triangulation of spatio-temporal data Sofie Haesevoets Bart Kuijpers An Abstract Model of Three-Dimensional Spatial Data Types Markus Schneider Brian E. Weinrich Return to GIS'04 Sessions ©2005 Association for Computing Machinery