Topological Canonization of Planar Spatial Data and Its Incremental Maintenance
نویسندگان
چکیده
It is known that to a planar spatial database represented by a semi algebraic set in the plane one can associate a structure here called the topological canonization such that two databases are topologically equivalent if and only if their topological canonizations are isomorphic The advantage of a topological canonization is that it contains precisely the information one needs if one is only interested in topological properties of the spatial data In this paper we represent semi algebraic sets using plane graph structures Canonizations are represented by plane graph structures as well the so called canonical structures We discuss the basic properties of canonical structures and of canonization We then present a method for incremental maintenance of the canonization under elementary updates on the original spatial database Incremental maintenance takes less time than recomputing the canonization from scratch Post doctoral research fellow of the Fund for Scienti c Research of Flanders FWO
منابع مشابه
3-connected Planar Graph Isomorphism is in Log-space
We consider the isomorphism and canonization problem for 3-connected planar graphs. The problem was known to be L -hard and in UL ∩ coUL [TW08]. In this paper, we give a deterministic log-space algorithm for 3-connected planar graph isomorphism and canonization. This gives an L -completeness result, thereby settling its complexity. The algorithm uses the notion of universal exploration sequence...
متن کاملافزایش سرعت نگهداری افزایشی دید با استفاده از الگوریتم فاخته
Data warehouse is a repository of integrated data that is collected from various sources. Data warehouse has a capability of maintaining data from various sources in its view form. So, the view should be maintained and updated during changes of sources. Since the increase in updates may cause costly overhead, it is necessary to update views with high accuracy. Optimal Delta Evaluation method is...
متن کاملA Log-space Algorithm for Canonization of Planar Graphs
Planar graph canonization is known to be hard for L this directly follows from L-hardness of tree-canonization [Lin92]. We give a log-space algorithm for planar graph canonization. This gives completeness for log-space under AC many-one reductions and improves the previously known upper bound of AC [MR91]. A planar graph can be decomposed into biconnected components. We give a log-space procedu...
متن کاملمدلسازی روابط توپولوژیک سه بعدی فازی در محیط GIS
Nowadays, geospatial information systems (GIS) are widely used to solve different spatial problems based on various types of fundamental data: spatial, temporal, attribute and topological relations. Topological relations are the most important part of GIS which distinguish it from the other kinds of information technologies. One of the important mechanisms for representing topological relations...
متن کاملMethodical Spatial Database Design with Topological Polygon Structures
Spatial databases form the foundation for a Spatial Data Infrastructure (SDI). For this, a spatial database should be methodically developed to accommodate its role in SDI. It is desirable to have an approach to spatial database development that considers maintenance from the early stage of database design and in a flexible way. Moreover, there is a lack of a mechanism to capture topological re...
متن کامل