Kurata, Y. (2009). Description of Movement from a Topological Viewpoint. in Hois, J. and Kurata, Y. (eds.) ICSC 2009 Symposium on "Spatial Models Meet Spatial Language", Rome, Italy, September 2009, Cognitive Processing 10(2) Speccial Issue ICSC 2009, pp.S135.

Abstract. People often describe a spatial movement with such spatial predicates as go into, come out, and pass through, from a viewpoint of how the moving entity transfers its location with respect to the inside, outside, and border of the area of interest. Geometrically, such transition of a moving entity is represented by a topological relation between a directed line segment and a region. In this presentation, we introduce a formal model of topological relations, called the 9⁺-intersection, which distinguishes 26 relations between a directed line and a region in a 2D space and 19 more relations in a 3D space. These relations are expected to have a strong correspondence with spatial predicates describing spatial movements. This correspondence is figured out on the analogy of the mapping between line-region relations and spatial predicates in the previous studies, since they this mapping reveals that even line-region configurations are often characterized by spatial predicates used for describing movements. Consideration of line's direction makes the mapping between line-region relations and spatial predicates more specific and useful for, for instance, automated generation of qualitative descriptions of spatial movements. We then discuss a practical issue of such description-generating process: how we should segment the trajectory of a moving entity in a meaningful way, if it is complicated, such that its movement is described as a sequence of spatial predicates. Five solutions are proposed and compared in an exploratory way.