• 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.

• 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.

• 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.

• Proceedings of the Korean Information Science Society Conference
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• 2003.10b
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• pp.160-162
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• 2003

공간데이터를 변형/왜곡하여 자세한 정도를 감소시킴으로서 공간데이터를 단순화하는 기법을 일반화라고 하는데, 이미 존재하는 데이터베이스로부터 새로운 축적의 데이터베이스를 유도할 때 이 기법을 활용할 수 있다. 본 연구에서는 다중축척 데이터베이스를 생성/관리하기 위한 일반화 시스템을 소개할 것이다. 이 시스템은 기존 연구들에 의해 제시된 일반화 연산자, 일관성 유지 방법들을 통합/개선하여 하나의 시스템으로 구현되었다 뿐만 아니라, 이 시스템에는 원시 데이터가 갱신되었을 때 이것을 유도된 다중축척 데이터베이스에 파급시킬 수 있는 방법과 사용자를 위한 모델 다이어그램 지원기능이 포함되어 있다. 본 연구에서 제시하는 다중축척 데이터베이스를 위한 도구는 다중축척 데이터를 유도(생성) 및 관리하기 위한 전체적인 틀을 제공하는 점에서 의의가 있다.