• The KIPS Transactions:PartD
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• v.12D no.6 s.102
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• pp.837-848
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• 2005

A multi-scale database is a set of spatial database, covering same geographic area with different scales and it can be derived from pre-existing databases. In the derivation processes of a new multi-scale spatial database, the geometries and topological relations on the source database can be transformed and the transformation can be the cause of the lack of integrity Therefore, it is necessary to assess the transformation whether it is consistent or not after the derivation process of a new multi-scale database. Thus, we propose assessment methods for the topological consistency between a source database and a derived multi-scale database in this paper. In particular, we focus on the case that 2-dimensional objects are collapsed to 1-dimensional ones in the derivation process of a multi-scale database. We also describe implementation of the assessment methods and show the results of the implementation with experimental data.

• Proceedings of the Korean Association of Geographic Inforamtion Studies Conference
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• 2004.10a
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• pp.27-40
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• 2004

When we derive multi-scale databases from a source spatial database, thegeometries and topological relations in the source database are transformed according to a predefined set of constraints. This means that the derived databases should be checked to see if the constraints are respected during the construction or updates of databases and to maintain the consistency of multi-scale databases. In this paper, we focus on the topological consistency between the source and derived databases, which is one of the important constraints to respect. In particular, we deal with the method of assessment of topological consistency, when 2-dimensional objects are collapsed to 1-dimensional ones. We introduce eight types of topological relations between 2-dimensional objects and 19 topological ones between 1-dimensional objects and propose four different strategies to convert 2-dimensional topological relations in the source database to 1-dimensional ones objects in the target database. With these strategies, we guarantee the topological consistency between multi-scale databases.

• Spatial Information Research
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• v.12 no.3
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• pp.239-249
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• 2004

This paper discusses on the update problem of multi-scale databases when the multi-scale databases, which is several spatial databases covering the same geographic area with different scales, are derived from an original one. Although the integrity between original and derived multi-scale databases should be maintained, most of update mechanisms do not 6respect it since the update mechanisms have assumed that the update of source objects propagates to objects directly derived from the source. In order to maintain the integrity of multi-scale databases during updates, we must propagate updates of sources to objects derived from both the updated source objects and other related objects. It is an important functional requirement of multi-scale database systems, which has not been supported by existing spatial database systems. In this paper, we propose a set of rules and algorithms for the update propagation and show a prototype developed on ArcGIS of ESRI. Our update mechanism provides with not only the consistency between multi-scale databases but also incremental updates.