• Spatial Information Research
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• v.5 no.1
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• pp.61-75
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• 1997

National Geographic Information System(NGIS) should be designed on the assumption that geographic data collected by each national organization should be integrated into geographic database systemically. To achieve this object, NGIS database would be better connected to National Very High-Speed Communication Network. In the process of research, some problems related to Korean NGIS are found. These are standardization, compatibility, extension, issue of making and opening digital map, and issue related to land information. So, it is required that pilot project apply National Geographic Information System in terms of National Very High-Speed computer network project. This project is to contain two main theme building of physical network and special management of network which is related with NGIS.

• Proceedings of the Korean Association of Geographic Inforamtion Studies Conference
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• 2003.04a
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• pp.77-82
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• 2003

The purpose of this study is to develop landslide susceptibility analysis techniques using artificial neural network and to apply the developed techniques to the study area of janghung in Korea. Landslide locations were identified in the study area from interpretation of satellite image and field survey data, and a spatial database of the topography, soil, forest and land use were consturced. The 13 landslide-related factors were extracted from the spatial database. Using those factors, landslide susceptibility was analyzed by artificial neural network methods, and the susceptibility map was made with a e15 program. For this, the weights of each factor were determinated in 5 cases by the backpropagation method, which is a type of artificial neural network method. Then the landslide susceptibility indexes were calculated using the weights and the susceptibility maps were made with a GIS to the 5 cases. A GIS was used to efficiently analyze the vast amount of data, and an artificial neural network was turned out be an effective tool to analyze the landslide susceptibility.

• Journal of Korea Multimedia Society
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• v.22 no.12
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• pp.1466-1480
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• 2019

This paper addresses the efficient processing of all-farthest-neighbors (AFN) queries in spatial network databases. Given a set of data points P={p₁,p₂,…,p_|p|} in a spatial network, where the distance between two data points p and s, denoted by dist (p,s), is the length of the shortest path between them, an AFN query is defined as follows: find the farthest neighbor ω(p)∈P of each data point p such that dist(p,ω(p)) ≥ dist(p,s) for all s∈P. In this paper, we propose a shared execution algorithm called FAST (for All-Farthest-neighbors Search in spatial neTworks). Extensive experiments on real-world roadmaps confirm the efficiency and scalability of the FAST algorithm, while demonstrating a speedup of up to two orders of magnitude over a conventional solution.

• 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.

• The KIPS Transactions:PartD
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• v.8D no.4
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• pp.377-386
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• 2001

In spatial database system, spatial view is supported for efficient access method to spatial database and is managed by materialization and non-materialization technique. In non-materialization technique, repeated execution on the same query makes problems such as the bottle-neck effect of server-side and overloads on a network. In materialization technique, view maintenance technique is very difficult and maintenance cost is too high when the base table has been changed. In this paper, the SVMT (Spatial View Materialization Technique) is proposed by using R-tree re-construction. The SVMT is a technique which constructs a spatial index according to the distribution ratio of objects in spatial view. This ratio is computed by using a SVHR (Spatial View Height in R-tree) and SVOC (Spatial View Object Count). If the ratio is higher than the average, a spatial view is materialized and the R-tree index is re-used. In this case, the root node of this index is exchanged a node which has a MBR (Minimum Boundary Rectangle) value that can contains the whole region of spatial view at a minimum size. Otherwise, a spatial view is materialized and the R-tree is re-constructed. In this technique, the information of spatial view is managed by using a SVIT (Spatial View Information Table) and is stored on the record of this table. The proposed technique increases the speed of response time through fast query processing on a materialized view and eliminates additional costs occurred from repeatable query modification on the same query. With these advantages, it can greatly minimize the network overloads and the bottle-neck effect on the server.

• Journal of Korean Society of Rural Planning
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• v.23 no.2
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• pp.43-54
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• 2017

When an age of low growth and population decline, population migration plays an important role in spatial structure of region. There have been many researches on migration and regional spatial structure. The purpose of this study is to examine the changes of Gwangju and Jeonnam region's spatial structure and central area using social network analysis methods. For analysis it was used that population and migration data and passenger OD(Origin and Destination) travel data released by Statistics Korea and Korea Transport Database(KTDB). Using Gephi 0.8.2, migration and passenger OD networks were visualized, and this describe network flow and density. The results of the network centrality analysis show that the most populated village is not always network center though population mass is an important factor of central places. The average eigenvector centrality of 2010 migration is the lowest during 2005-2015, and it means few regions have high centralities. When comparing migration and travel networks, travel data is more effective than migration data in determining the central location considering spatial functions.

• Proceedings of the Korea Committee for Ocean Resources and Engineering Conference
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• 2004.05a
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• pp.61-66
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• 2004

In this paper an effort is made to develop an innovative spatial arrangement concept pertaining to ship building industry. The spatial scheduling is the problem that concentrates on effective planning of available space and arrangements of blocks and in a priority manner. In order to create an effective spatial scheduling. a database providing the priority has to be available to make the erection sequence. Such a system works hand in hand with erection sequence generator program The erection sequence program works on the conventional network analysis method which uses a typical parent-children idea for the calculation of the ENT(possible earliest network start time) and LNT(possible latest network start time). This program works in a cyclic manner taking turns by calculating the ENT in upward trace and LNT on the return trace thereby generating the entire erection sequence diagram for the requisite problem The generated database serves as an input data for spatial scheduling problem. When the system works it takes into consideration the entire system based on heuristic concepts as mentioned. There system uses the spatial aspects such as the available area of the P. E area and plan area of the corresponding blocks and its priority of erection from the erection sequence generator program develops the spatial scheduling arrangement. In this paper using all these concepts an innovative spatial schedule development system developed.

• The KIPS Transactions:PartD
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• v.10D no.4
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• pp.591-602
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• 2003

Delay and discontinuance phenomenon of service are cause by sudden increase of the network communication amount and the quantity consumed of resources when Internet users are driven excessively to a conventional single large database sewer. To solve these problems, spatial database cluster consisted of several single nodes on high-speed network to offer high-performance is risen. But, research about spatial join operation that can reduce the performance of whole system in case process at single node is not achieved. So, in this paper, we propose efficient parallel spatial join processing method in a spatial database cluster system that uses data partitions and replications method that considers the characteristics of space data. Since proposed method does not need the creation step and the assignment step of tasks, and does not occur additional message transmission between cluster nodes that appear in existent parallel spatial join method, it shows performance improvement of 23% than the conventional parallel R-tree spatial join for a shared-nothing architecture about expensive spatial join queries. Also, It can minimize the response time to user because it removes redundant refinement operation at each cluster node.

• Journal of Communications and Networks
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• v.16 no.2
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• pp.202-208
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• 2014

Wireless network information services allow end systems to discover heterogeneous networks and spectrum available for secondary use at or near their current location, helping them to cope with increasing traffic and finite spectrum resources. We propose a unified architecture that allows end systems to find nearby base stations that are using either licensed, shared or unlicensed spectrum across multiple network operators. Our study evaluates the performance and scalability of spatial databases storing base station coverage area geometries. The measurement results indicate that the current spatial databases perform well even when the number of coverage areas is very large. A single logical spatial database would likely be able to satisfy the query load for a large national cellular network. We also observe that coarse geographic divisions can significantly improve query performance.

• Health Policy and Management
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• v.27 no.3
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• pp.229-240
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• 2017

Background: This study purposed to analyze the spatial accessibility of women in childbearing age to the healthcare organizations (HCOs) providing delivery services in Gangwon-do. Methods: Network analysis was applied to assess the spatial accessibility based on the travel time and road travel distance. Travel time and travel distance were measured between the location of HCOs and the centroid of the smallest administrative areas, eup, myeon, and dong in Gangwon-do. Korean Transport Database Center provided road network GIS (Geographic Information System) Database in 2015 and it was used to build the network dataset. Two types of network analysis, service area analysis and origin-destination (OD)-cost matrix analysis, applied to the created network dataset. Service area analysis defined all-accessible areas that are within a specified time, and OD-cost matrix analysis measured the least-cost paths from the HCOs to the centroids. The visualization of the number of the HCOs and the number of women in childbearing age on the Ganwon-do map and network analysis were performed with ArcGIS ver. 10.0 (ESRI, Redlands, CA, USA). Results: Twenty HCOs were providing delivery services in Gangwon-do in 2016. Over 50% of the women in childbearing age were aged more than 35 years. Service area analysis found that 89.56% of Gangwon-do area took less than 60 minutes to reach any types of HCOs. For tertiary hospitals, about 74.37% of Gangwon-do area took more than 60 minutes. Except Wonju-si and Hoengseong-gun, other regions took more than 60 minutes to reach the tertiary hospital. Especially, Goseong-gun, Donghae-si, Samcheok-si, Sokcho-si, Yanggu-gun, Cheorwon-gun, and Taebaek-si took more than 100 minutes to the tertiary hospital. Conclusion: This study provided that the accessibility toward the tertiary hospital was limited and it may cause problems in high-risk delivery patients such as over 35 years. Health policy makers will need to handle the obstetric accessibility issues in Gangwon-do.