• Spatial Information Research
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• v.11 no.4
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• pp.493-508
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• 2003

This study proposes a framework of a GIS service network to connect local governments'Land Management Information Systems(LMIS) together. Databases constructed far LMIS's are very crucial information on both administrative business and civil affairs administration. However, they did not give full play to their values because they could not be shared sufficiently. Local governments build their databases individually using diverse GIS solutions. It causes some problems on sharing them. To demonstrate their geniuses, they should be connected to each other within a network for the whole country, and are served whenever and wherever to people who require them. for this, there are two main problems to be solved. Firstly, a GIS service network that handles heterogeneous and distributed computing environments is organized to link every LMIS each other by the GIS service network vertically and horizontally. Secondly, a mechanism should be developed to access the GIS service network readily and to search GIS data efficiently. The needs from every types of user should be satisfied by the mechanism. As the result of investigation of the issues, one of the most possible solution was suggested in this study, which is a Web based approach. To take into account the advance of information technology in the future and the requirements of e-government, stepwise strategies that integrate the LMIS's into a Web based system was recommended.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.32 no.2
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• pp.95-107
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• 2014

In general, topographical phenomena are represented graphically by data in the spatial domain, while attributes of the non-spatial domain are expressed by alpha-numeric texts. GIS functions for analysis of attributes in the non-spatial domain remain quite simple, such as search methods and simple statistical analysis. Recently, graph modeling and network analysis of social phenomena are commonly used for understanding various social events and phenomena. In this study, we applied the network analysis functions to the non-spatial domain data of GIS to enhance the overall spatial analysis. For this purpose, a novel design was presented to integrate the spatial database and the graph database, and this design was then implemented into a WebGIS system for better decision makings. The developed WebGIS with underlying synchronized databases, was tested in a simulated application about the selection of water supply households during an epidemic of the foot-and-mouse disease. The results of this test indicate that the developed WebGIS can contribute to improved decisions by taking into account the social proximity factors as well as geospatial factors.

• Journal of KIISE:Computing Practices and Letters
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• v.14 no.2
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• pp.196-200
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• 2008

Recently, the query processing algorithm in spatial network database (SNDB) has attracted many interests. However, there is little research on route-based query processing algorithm in SNDB. Since the moving objects moves only in spatial networks, the route-based algorithm is very useful for LBS and Telematics applications. In this paper, we analyze In-Route Nearest Neighbor (IRNN) query, which is an typical one of route-based queries, and propose a new IRNN query processing algorithm with time constraint. In addition, we show from our performance analysis that our IRNN query processing algorithm with time constraint is better on retrieval performance than the existing IRNN query processing one.

• Proceedings of the Korean Information Science Society Conference
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• 2004.10b
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• pp.133-135
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• 2004

이동 객체를 위한 기존 연구는, 제한조건이 없는 이상적인 공간을 가정하고 설계되었으나, 이는 실제 응용에 직접 적용하는데 문제를 지니고 있다. 따라서 본 논문에서는 LBS (location-based service) 의 효과적인 지원을 위해, 이상적인 공간대신, 실제 도로나 철도와 같은 공간 네트워크(network)를 고려하며, 아울러, 이러한 공간네트워크 데이터베이스를 위한 효율적인 저장 및 색인 구조를 설계한다.

• Journal of Korea Spatial Information System Society
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• v.9 no.2
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• pp.35-53
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• 2007

GML is a mark-up language which is suggested by OGC(Open GIS Consortium) for use of encoding standard concerning with storing and transferring Geographic information. For general spatial network database, researches supporting GML documents can be classified into three categories : parsing, storing, and retrieval of GML documents. Among them, the 'Storing of GML document' is essential for efficient GML document retrieval. However, There is little research on schema for storing GML documents. In addition, the existing schema for storing XML documents can't be used for GML documents due to geographic information. Therefore, In this paper, we propose efficient schema for storing GML documents In addition, we do performance evaluation of the GML schema.

• Journal of KIISE:Databases
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• v.35 no.2
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• pp.169-181
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• 2008

Because moving objects usually move on spatial networks, efficient trajectory index structures are required to achieve good retrieval performance on their trajectories. However, there has been little research on trajectory index structures for spatial networks such as FNR-tree and MON-tree. But, because FNR-tree and MON-tree are stored by the unit of the moving object's segment, they can't support the whole moving objects' trajectory. In this paper, we propose an efficient trajectory index structure, named Trajectory of Moving objects on Network Tree(TMN Tree), for moving objects. For this, we divide moving object data into spatial and temporal attribute, and preserve moving objects' trajectory. Then, we design index structure which supports not only range query but trajectory query. In addition, we divide user queries into spatio-temporal area based trajectory query, similar-trajectory query, and k-nearest neighbor query. We propose query processing algorithms to support them. Finally, we show that our trajectory index structure outperforms existing tree structures like FNR-Tree and MON-Tree.

• Journal of the Economic Geographical Society of Korea
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• v.18 no.4
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• pp.539-555
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• 2015

This study proposes the methodology for measuring the time-distance accessibility on the Seoul bus system based on the T-card transaction databases and analyzes the results. T-card transaction databases contain the time/space information of each passenger's locations and times of the departure, transfers, and destination. We introduce the bus network graph and develop the algorithms for time-distance accessibility measurement. We account the average speed based on each passenger's get-in and getoff information in the T-card data as well as the average transfer time from the trip chain transactions. Employing the modified Floyd APSP algorithm, the shortest time distance between each pair of bus stops has been accounted. The graph-theoretic nodal accessibility has been given by the sum of the inverse time distance to all other nodes on the network. The results and spatial patterns are analyzed. This study is the first attempt to measure the time-distance accessibility for such a large transport network as the Seoul bus system consists of 34,934 bus stops on the 600 bus routes, and each bus route can have different properties in terms of speed limit, number of lanes, and traffic signal systems, and thus has great significance in the accessibility measurement studies.

• Journal of Korea Spatial Information System Society
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• v.9 no.3
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• pp.67-80
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• 2007

Recently, many studies on query processing algorithms has been done for spatial networks, such as roads and railways, instead of Euclidean spaces, in order to efficiently support LBS(location-based service) and Telematics applications. However, both a closest pairs query and an e-distance join query require a very high cost in query processing because they can be answered by processing a set of POIs, instead of a single POI. Nevertheless, the query processing cost for closest pairs and e-distance join queries is rapidly increased as the number of k (or the length of radius) is increased. Therefore, we propose both a closest pairs query processing algorithm and an e-distance join query processing algorithm using a POI-based materialization technique so that we can process closest pairs and e-distance join queries in an efficient way. In addition, we show the retrieval efficiency of the proposed algorithms by making a performance comparison of the conventional algorithms.

• Proceedings of the Korean Society of Computer Information Conference
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• 2021.07a
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• pp.223-224
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• 2021

Recently, k-farthest neighbor (kFN) queries have not as much attention as k-nearest neighbor (kNN) queries. Therefore, this study considers moving k-farthest neighbor (MkFN) queries for spatial network databases. Given a positive integer k, a moving query point q, and a set of data points P, MkFN queries can constantly retrieve k data points that are farthest from the query point q. The challenge with processing MkFN queries in spatial networks is to avoid unnecessary or superfluous distance calculations between the query and associated data points. This study proposes a batch processing algorithm, called MOFA, to enable efficient processing of MkFN queries in spatial networks. MOFA aims to avoid dispensable distance computations based on the clustering of both query and data points. Moreover, a time complexity analysis is presented to clarify the effect of the clustering method on the query processing time. Extensive experiments using real-world roadmaps demonstrated the efficiency and scalability of the MOFA when compared with a conventional solution.

• Proceedings of the Korean Society of Surveying, Geodesy, Photogrammetry, and Cartography Conference
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• 2002.04a
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• pp.17-24
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• 2002

Mechanization is the characteristic of the industrial era and computerization is the characteristic of the Information Era. Now we are facing on the transition from Industrial Era to information Era. Established the National Geo-spatial Data Infrastructures is the fundamental base for information society and is one part of the national basic economic development plan. From 1980's China started his successful transition from traditional methods to high-tech based mapping. China has laid out a high accuracy national GPS (global Positioning System) network, and completed the geographic information databases for scale of 1:1million and 1:250,000. Now it is working on the databases for scales of 1:50,000 and 1:10,000, the world highest level. The massive national programmed has been dubbed "Digital China," since it involves massive quantities of digitized geographical information. Simultaneity, GIS technology and the geo-spatial data have been used widely in electronic government affair, environmental protection, disaster control, ITS and etc. The users have realized the benefits more and more widely. Internet is an efficient way to distribute the geo-information, the State Bureau of Surveying and Mapping has give great effort to settle down the rules and standards to establish the clearing house. Some National Geo-standards have issued, and some of them are on the way. The GIS software is another important factor in the GIS industry. Chinese government working-out some good policy to supports the GIS software developer to have their own copyright. This paper is based on the above to introduce the status and development of Geomatics in China. in China.