Teruhiko Teraoka

A Spatial Data Structure for the 3D Graphical Facility Management System

Abstract Geographical information systems (GISs) are now used extensively in the analysis of environmental data due to their capability to manage, manipulate, and display spatial data. However, most of the GIS applications (such as facility management system) possess data management structures that deal with only 2 dimentional space. The 3D system that enables users to explore the 3D space interactively and examine 3D spatial views of the environments would be very useful. In this paper, we propose a spatial data management method for a 3D graphical facility management system. Using this method, we have developed prototype 3D graphical management system that offers interacive operations with the 3D virtual city environments.

Recognition of 3D flexible objects by GRBF

Recently Poggio and Edelman have shown that for each object there exists a smooth mapping from an arbitrary view to its standard view and that the mapping can be learned from a sparse data set. In this paper, we extend their scheme further to deal with 3D flexible objects. We show the mappings from an arbitrary view to the standard view, and its rotated view can be synthesized even for a flexible object by learning from examples. To classify 3D flexible objects, we propose two methods, which do not require any special knowledge on the target flexible objects. They are: (1) learning the characteristic function of the object and (2) learning the view-change transformation. We show their performance by computer simulations.

The multidimensional persistent tree: A spatiotemporal data management structure suitable for spatial search

Multidimensional data structures have been proposed for management of spatial data including points, lines, and regions. Concomitantly, more research on temporal databases as a way to handle temporal information is needed. Although the management of spatiotemporal data becomes increasingly important in geographic information systems and computer-aided design, these data structures cannot manage spatiotemporal data efficiently. In this paper, the MP-tree (multidimensional persistent tree) is proposed for handling multidimensional data with insertion/deletion version without the loss of efficiency of a spatial search. The MP-tree is developed by extending conventional spatial data structure using techniques of Persistent Search Tree. The advantages and disadvantages of conventional methods with respect to both search and memory efficiency are discussed. Finally, using computer simulations, the MP-tree is shown to have better performances for both range search and spatiotemporal search.

Spatio-Temporal Data Management for a 3D Graphical Information System

In this paper, we propose a spatio-temporal data management method for a 3D graphical facility management system. To provide highly interactive environment, we propose a 3D spatial data management method based on multiple 2D-trees. With the method, interactive operations such as smooth walkthrough and interactive information retrieval in 3D space are made possible. Then, we augment the data structure to deal with the temporal information as well as the spatial information. MP-tree is proposed for spatio-temporal data management. With the use of the data structure, efficient temporal search is made possible keeping the performance of spatial search. We also present a 3D electric facility management system using our data management method.