• Journal of Information Technology Services
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• v.12 no.3
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• pp.389-404
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• 2013

Geospatial information, which is one of social overhead capital, is predicted as a core growing industry for the future. The production of geospatial information requires a huge budget, so it is very important objective of the policy for geospatial information to prevent the duplication of geospatial projects. In this paper, we proposed a semantic search system which extracts possible duplication of geospatial projects by using ontology for geospatial project administration. In order to achieve our goal, we suggested how to construct and utilize geospatial project ontology, and designed the architecture and process of the semantic search. Moreover, we showed how the suggested semantic search works with a duplicated projects search scenario. The suggested system enables a nonprofessional can easily search for duplicated projects, therefore we expect that our research contributes to effective and efficient duplication review process for geospatial projects.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.29 no.5
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• pp.449-457
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• 2011

As automated image processing techniques have been required in multi-temporal/multi-sensor geospatial image applications, use of automated but highly invariant image matching technique has been a critical ingredient. Note that there is high possibility of geometric and spectral differences between multi-temporal/multi-sensor geospatial images due to differences in sensor, acquisition geometry, season, and weather, etc. Among many image matching techniques, the SIFT (Scale Invariant Feature Transform) is a popular method since it has been recognized to be very robust to diverse imaging conditions. Therefore, the SIFT has high potential for the geospatial image processing. This paper presents a performance test results of the SIFT on geospatial imagery by simulating various image differences such as shear, scale, rotation, intensity, noise, and spectral differences. Since a geospatial image application often requires a number of good matching points over the images, the number of matching points was analyzed with its matching positional accuracy. The test results show that the SIFT is highly invariant but could not overcome significant image differences. In addition, it guarantees no outlier-free matching such that it is highly recommended to use outlier removal techniques such as RANSAC (RANdom SAmple Consensus).

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.26 no.1
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• pp.1-7
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• 2008

The government is spending a large amount of budget to establish NGIS due to the importance of geospatial information. This paper deals with the study of schema mapping technique which can efficiently establish military topographic DB forest layer using digital forest map and other existing geospatial DB. In order to accomplish this each schema of these types of DB was analyzed then, mapping table which connects related attributes was created and finally, military topographical DB forest layer of the area of interest was efficiently established. This research was able to display solutions that resolved compatibility issues between existing geospatial DB of these types, established by the schema mapping techniques described in this research.

• Korean Journal of Remote Sensing
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• v.36 no.5_2
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• pp.917-927
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• 2020

The Ministry of Land, Infrastructure and Transport of Korea is developing a CAS 500-1/2 satellite capable of photographing a GSD 0.5 m level image, and is developing a technology to utilize this. Therefore, this study attempted to develop a geospatial feature extraction technique aimed at automation as a technique for utilizing CAS 500-1/2 satellite images. KOMPSAT-3A satellite images that are expected to be most similar to CAS 500-1/2 were used for research and the possibility of automation of geospatial feature extraction was analyzed through relative radiometric normalization. For this purpose, the parameters and thresholds were applied equally to the reference images and relative radiometric normalized images, and the geospatial feature were extracted. The qualitative analysis was conducted on whether the extracted geospatial feature is extracted in a similar form from the reference image and relative radiometric normalized image. It was also intended to analyze the possibility of automation of geospatial feature extraction by quantitative analysis of whether the classification accuracy satisfies the target accuracy of 90% or more set in this study. As a result, it was confirmed that shape of geospatial feature extracted from reference image and relative radiometric normalized image were similar, and the classification accuracy analysis results showed that both satisfies the target accuracy of 90% or more. Therefore, it is believed that automation will be possible when extracting spatial objects through relative radiometric normalization.

• Proceedings of the Korean Society of Surveying, Geodesy, Photogrammetry, and Cartography Conference
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• 2007.04a
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• pp.257-260
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• 2007

The government is spending a large amount of budget to establish NGIS due to the importance of geospatial information. This paper deals with the study of schema mapping technique which can efficiently establish military topographic DB forest layer using digital forest map and other existing geospatial DB. In order to accomplish this 1) each schema of these types of DB was analyzed then, 2) mapping table which connects related attributes was created and finally, 3) military topographical DB forest layer of the area of interest was efficiently established. This research was able to display solutions that resolved compatibility issues between existing geospatial DB of these types, established by the schema mapping techniques described in this research.

• Journal of Korean Society for Geospatial Information Science
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• v.16 no.4
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• pp.73-78
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• 2008

The present study was aimed to estimate the urban sprawl in a historical city of India using series of satellite data between 1968 and 2005(37 years) and GIS. The total area of the Tiruchirappalli city was 1991.96 ha during 1968 and it was expanded into 4335.98 ha(117.67%) during 2005. The average growth rate per year was 63.35 ha. This 117.67% growth was at the cost of agriculture land(97.81%) and water body(2.19%). The satellite data used in this study were found to be good source of information for this kind of analysis and further studies are need to estimate the impact of this city expansion on agriculture yield and ground water.

• Proceedings of the Korea Water Resources Association Conference
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• 2020.06a
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• pp.85-85
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• 2020

South Korea experiences few large scale erosion and sedimentation problems, however, there are numerous local sedimentation problems. A reliable and consistent approach to modelling and management for sediment processes are desirable in the country. In this study, field measurements of sediment concentration from 34 alluvial river basins in South Korea were used with the Modified Einstein Procedure (MEP) to determine the total sediment load at the sampling locations. And then the Flow Duration-Sediment Rating Curve (FD-SRC) method was used to estimate the specific degradation for all gauging stations. The specific degradation of most rivers were found to be typically 50-300 tons/㎢·yr. A model tree data mining technique was applied to develop a model for the specific degradation based on various watershed characteristics of each watershed from GIS analysis. The meaningful parameters are: 1) elevation at the middle relative area of the hypsometric curve [m], 2) percentage of wetland and water [%], 3) percentage of urbanized area [%], and 4) Main stream length [km]. The Root Mean Square Error (RMSE) of existing models is in excess of 1,250 tons/㎢·yr and the RMSE of the proposed model with 6 additional validations decreased to 65 tons/㎢·yr. Erosion loss maps from the Revised Universal Soil Loss Equation (RUSLE), satellite images, and aerial photographs were used to delineate the geospatial features affecting erosion and sedimentation. The results of the geospatial analysis clearly shows that the high risk erosion area (hill slopes and construction sites at urbanized area) and sedimentation features (wetlands and agricultural reservoirs). The result of physiographical analysis also indicates that the watershed morphometric characteristic well explain the sediment transport. Sustainable management with the data mining methodologies and geospatial analysis could be helpful to solve various erosion and sedimentation problems under different conditions.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.23 no.6
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• pp.637-644
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• 2019

In recent years, many public safety systems in the smart city are developed. These systems are taking responsibility to make a safe and comfortable city. In this paper, we propose vehicle tracking systems include a public safety system that enables the policeman to track the stolen vehicles more efficiently by providing the vehicle information in real time. When a vehicle is stolen, the vehicle owner can send a user emergency request. Then, the public safety server which supported by a geospatial query technique will give information such as time, distance, and routes to a policeman who is closest to the location of the vehicle to catch the thief. 300 simulations were performed to evaluate the performance of the system. We found that the average of times required when vehicle owner send a user emergency message on user application until policeman obtain a vehicle tracking request on police application below 1.2 seconds.

• Journal of Korean Society for Geospatial Information Science
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• v.4 no.1 s.6
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• pp.17-21
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• 1996

To realize GIS on internet two methods are possible. One is using java language and the other is using window API that interface with internet WWW HTTP protocol. GIS program needs to extract, classify, store in various geospatial data. But WWW HTML are statical and Impossible to input multi points and area selectioning. This study applied JAVA in Web GIS so that may handle various geographic data on internet, communicate interactively GUI interface and present, modify and powered with various means of cartographic visualization

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.1
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• pp.768-773
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• 2020

In large-scale land development for the rational use and management of national land resources, the use of geospatial information is essential for the efficient management of projects. Recently, drone LiDAR (Light Detection And Ranging) has attracted attention as an effective geospatial information construction technique for large-scale development areas, such as housing site construction and open-pit mines. Drone LiDAR can be classified into a method using SLAM (Simultaneous Localization And Mapping) technology and a GNSS (Global Navigation Satellite System)/IMU (Inertial Measurement Unit) method. On the other hand, there is a lack of analytical research on the application of drone LiDAR or the characteristics of each method. Therefore, in this study, data acquisition, processing, and analysis using SLAM and GNSS/IMU type drone LiDAR were performed, and the characteristics and utilization of each were evaluated. As a result, the height direction accuracy of drone LiDAR was -0.052~0.044m, which satisfies the allowable accuracy of geospatial information for mapping. In addition, the characteristics of each method were presented through a comparison of data acquisition and processing. Geospatial information constructed through drone LiDAR can be used in several ways, such as measuring the distance, area, and inclination. Based on such information, it is possible to evaluate the safety of large-scale development areas, and this method is expected to be utilized in the future.