• Proceedings of the KSRS Conference
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• 2002.10a
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• pp.117-122
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• 2002

In this paper, we propose Media GIS web service architecture using 3D geographical database and GPS-related data resulted from 4S-Van. We introduce a novel interoperable geographical data service concept; so-called, Virtual World Mapping (VWM) that can map 3D graphic world with real-world video. Our proposed method can easily retrieve geographical in-formation and attributes to reconstruct 3D virtual space according to certain frame in video sequences. Our proposed system architecture also has an advantage that can provide geographical information service with video stream without any image processing procedures. In addition to, describing the details of our components, we present a Media GIS web service system by using GeoVideo Server, which performs VWM technique.

• Journal of KIISE
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• v.42 no.5
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• pp.652-663
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• 2015

Due to the popularity of location-based services, the amount of generated spatial data in daily life has been dramatically increasing. Therefore, spatial database outsourcing has become popular for data owners to reduce the spatial database management cost. The most important consideration in database outsourcing is meeting the privacy requirements and guarantying the integrity of the query result. However, most of existing database transformation techniques do not support both of the data privacy and integrity of the query result. To solve this problem, we propose a spatial data transformation scheme that utilizes the shearing transformation with rotation shifting. In addition, we described the attack models to measure the data privacy of database transformation schemes. Finally, we demonstrated through the experimental evaluations that our scheme provides high level of data protection against different kinds of attack models, compared to the existing schemes, while guaranteeing the integrity of the query result sets.

• Spatial Information Research
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• v.9 no.2
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• pp.353-368
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• 2001

Recently central and local governments developed a huge spatial database and system using full-scale Geographic Information System (GIS). But Inconsistent spatial data through duplicated database management drops off in efficiency and confidence of administration. It is difficult to share data because of their unique system and data type. Under these circumstances Ministry of Construction and Transportation (MOCT) has been carrying out Land Management Information System (LMIS) to computerize land administration and policy affairs and to implement land database such as law, spatial, attribute data. A prerequisite mission of LMIS is to develop open system for solving the problem of duplicated data management and data sharing and for supporting various computer environments such as hardware, software, network etc. The purpose of LMIS is to reuse the existing investment resources and to expand the existing system resources. Therefore the purpose of this study is to investigate a method of LMIS operation under the existing circumstances and expansion of the system in the future. To do this, Supporting various DBMS, GIS server, Distributing Computing Platform(Unix, NT Server) is needed. Especially LMIS need to be developed as open system with interoperability to get independence of application from various GIS servers.

• Journal of KIISE:Databases
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• v.29 no.5
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• pp.393-403
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• 2002

One of the major issues of DBMS is the buffer management. Because fetching data from the database disk is costly, the number of disk I/O's must be minimized in order to improve the DBMS performance. Although there have been many buffer management strategies to minimize the disk I/O, those strategies usually focused on just the temporal locality. Since there are the spatial locality as well as the temporal locality in the spatial database, strategies using only the temporal locality cannot achieve the optimal performance in the spatial database. In this paper, we propose a new buffer management strategy, the Spatial Locality Area Measure(SLAM) strategy, that considers not only the temporal locality but also the spatial locality. The SLAM buffer management strategy consists of two core structures, the SLM-tree and the M-LRU. We show the efficiency of the proposed strategy through experiments over various buffer sizes and reference frequencies.

• Proceedings of the KSRS Conference
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• 2003.11a
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• pp.138-140
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• 2003

The aim of this study is to evaluate the effect of spatial resolutions on the accuracy to landslide susceptibility mapping. For this, landslide locations were identified in the Boun, Korea from interpretation of aerial photographs and field surveys. The topographic, soil, forest, geologic, linearment and land use data were collected, processed and constructed into a spatial database using GIS and remote sensing data. The 15 factors that influence landslide occurrence were extracted and calculated from the spatial database with 5m, 10m, 30m, 100m and 200m spatial resolutions. Landslide hazardous area were analysed and mapped using the landslide-occurrence factors by probability model, likelihood ratio, for the five cases spatial resolutions. The results of the analysis were verified using the landslide location data. In the cases of spatial resolution 5m, 10m and 30m, the verification results was similar, but in the cases of 100m and 200m the results worse than the others. Because the scale of input data was 1:5,000 ? 1:50,000, so the cases of 5m, 10m and 30m have similar accuracy but the cases of 100m and 200m have the lower accuracy. From this, there is an effect of spatial resolutions on accuracy and landslide susceptibility mapping the result is dependent on input map.

• Proceedings of the KSRS Conference
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• 2005.10a
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• pp.753-758
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• 2005

This study attempts at building an integrated GIS computing framework for evaluating space-time accessibility of an individual with the approach of time geography model. The proposed method is based on the integration of mobile GIS and object-relational spatio-temporal database. Three components are central to our system: ( i ) mobile GIS application that transmits spatio-temporal trajectory data of an individual; ( ii ) spatio-temporal database server that incorporates the time geography model; and (iii) geovisualization client that provides time geographic queries to the spatio-temporal database. As for the mobile GIS application, spatio-temporal trajectory data collected by GPS-PDA client is automatically transmitted to the database server through mobile data management middleware. The spatio-temporal database server implemented by extending a generic DBMS provides spatio-temporal objects, functions and query languages. The geovisualization client illustrates 3D visual results of the queries about space-time path. space-time prism and space-time accessibility. This study shows a method of integrating mobile GIS and DBMS for time geography application, and presents an appropriate spatio-temporal data model for evaluating space-time accessibility of an individual.

• The Transactions of the Korea Information Processing Society
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• v.6 no.1
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• pp.11-20
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• 1999

Because conventional spatial databases process the spatial information that is valid at current time, it is difficult to manage historical information efficiently which has been changed from the past to current. Recently, there are rapid increasing of interest to solve this problem so that makes databases to support historical information as well as spatial management at the same time. It can be eventually used in a various application areas. The formal semantics in a database is used to represent database structures and operations in order to prove the correctiveness of them in terms or mathematics. It also plays an important role in database to design a database and database management system. So in this paper, we suggest spatiotemporal domain, object, data, and spatiotemporal geometric/topological operations. And we not only formalize relational algebra/calculus using formal semantics for a spatiotemporal data model, but also show the example of real orld with them.

• Journal of the Korean Association of Geographic Information Studies
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• v.13 no.4
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• pp.1-11
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• 2010

This study proposed the method for the SWMM data generation connected with the spatial database and designed the data model in order to display flooding information such as the runoff sewer system, flooding areas and depth. A variety of data, including UIS, documents related to the disasters, and rainfall data are used to generate the attributes for flooding analysis areas. The spatial data is constructed by the ArcSDE and Oracle DB. The prototype system is also developed to display the runoff areas based on the GIS using the ArcGIS ArcObjects and spatial DB. The results will be applied to the flooding analysis based on the SWMM.

• Journal of Korea Spatial Information System Society
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• v.5 no.2 s.10
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• pp.5-21
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• 2003

Sptaio-temporal databases are important to store the real-time location information of large spatio-temporal objects efficiently and retrieve them rapidly. Accordingly necessity for spatio-temporal database system that can manage spatial information, aspatial information and temporal information of spatio-temporal objects is increasing. Sptaio-temporal databases are important to store the real-time location information of large spatio-temporal objects efficiently and retrieve them rapidly. Accordingly necessity for spatio-temporal database system that can manage spatial information, aspatial information and temporal information of spatio-temporal objects is increasing. Therefore, in this paper, we propose a spatio-temporal data model that is able to efficiently manage historical spatio-temporal objects that change dynamically their states as time. Also, various spatio-temporal operations and constraint conditions are defined to keep integrity of spatio-temporal data and spatio-temporal operations.

• Journal of KIISE:Databases
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• v.31 no.4
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• pp.362-372
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• 2004

One of the most difficult problems in building a distributed GIS lies in the heterogeneity of spatial databases. In particular, positional mismatches between spatial databases, which arise due to several reasons, may incur incorrect query results. They result in unreliable outputs of query processing. One simple solution is to correct positional data in spatial databases at each site, according to the most accurate one. This solution is however not practical in cases where the autonomy of each database should be respected. In this paper, we propose a spatial query processing method without correcting positional data in each spatial database. Instead of correcting positional data, we dynamically transform a given query region or position onto each space where spatial objects of each site are located. Our proposed method is based on an elastic transformation method by using delaunay triangulation. Accuracy of this method is proved mathematically, and is confirmed by an experiment. Moreover, we implemented using common use database system for usefulness verification of this method.