• KCID journal
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• v.21 no.1
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• pp.45-54
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• 2014

In this study, Agricultural Infrastructures of Shincheon-gun in North Korea are investigated using Kompsat-2 and RapidEye satellite imagery. Target agricultural infrastructures are agricultural landuse, irrigation and drainage canals, dammed pools for irrigation and pumping stations. KOMPSAT-2 satellite imagery are use to investigate agricultural hydraulic structures and agricultural landuse are investigated by RapidEye Imagery. Geometric correction are performed using 28 GCP and QUAC method are used for atmospherical correction in all imagery. ISODATA clustering and naked-eye classification method are used for extracting agricultural hydraulic structures and Object-based analysis is applied to classifying the agricultural landuse. Extraction results of agricultural hydraulic structures and agricultural are presented and we suggest the applicability of satellite imagery to investigate agricultural infrastructures in North Korea.

• Korean Journal of Remote Sensing
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• v.24 no.6
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• pp.641-644
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• 2008

In order to improve a camera rotation calculation based on the bundle adjustment in Chon's camera motion (Chon and Shankar, 2007, 2008), this paper introduces a method calculating the camera rotation. It estimates a unit vector in the optical axis of a camera through the angles between the optical axis and vectors passing a camera position and ground control points (GCP). The camera position is estimated by using the inner product method proposed by Chon. The horizontal and vertical unit vectors of the camera are determined by using Yakimovsky and Cunningham's camera model (CAHV) (1978).

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.38 no.4
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• pp.327-343
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• 2020

This study proposes a method to improve the geometric quality of KOMPSAT (Korea Multi-Purpose Satellite)-3/3A Level 1R imagery, particularly for efficient disaster damage analysis. The proposed method applies a novel grid-based SIFT (Scale Invariant Feature Transform) method to the Planetscope ortho-imagery, which solves the inherent limitations in acquiring appropriate optical satellite imagery over disaster areas, and the KOMPSAT-3/3A imagery to extract GCPs (Ground Control Points) required for the RPC (Rational Polynomial Coefficient) bias compensation. In order to validate its effectiveness, the proposed method was applied to the KOMPSAT-3 multispectral image of Gangnueng which includes the April 2019 wildfire, and the KOMPSAT-3A image of Daejeon, which was additionally selected in consideration of the diverse land cover types. The proposed method improved the geometric quality of KOMPSAT-3/3A images by reducing the positioning errors(RMSE: Root Mean Square Error) of the two images from 6.62 pixels to 1.25 pixels for KOMPSAT-3, and from 7.03 pixels to 1.66 pixels for KOMPSAT-3A. Through a visual comparison of the post-disaster KOMPSAT-3 ortho-image of Gangneung and the pre-disaster Planetscope ortho-image, the result showed appropriate geometric quality for wildfire damage analysis. This paper demonstrated the possibility of using Planetscope ortho-images as an alternative to obtain the GCPs for geometric calibration. Furthermore, the proposed method can be applied to various KOMPSAT-3/3A research studies where Planetscope ortho-images can be provided.

• Journal of the Korean GEO-environmental Society
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• v.13 no.3
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• pp.53-58
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• 2012

In general, sand compaction pile(SCP) method and gravel compaction pile(GCP) method have been mainly used to reinforce soft soils such as soft clay or loose sandy ground. But the sand compaction pile method has problems such as lack of sand supply and destroying the nature while collecting sand, the gravel compaction pile method has a problem such as decreased permeability of the drainage material due to clogging. Recently, the study to replace sand with bottom ash which has similar engineering properties with sand is in active. As a fundamental research on bottom ash mixture compaction pile utilizing bottom ash, its behavioral characteristics depending on granular materials and replacement ratio has been simulated numerically. In particular, Settlement Reduction Ratio(SRR) according to the distance from the center of pile was calculated. The main findings were as follows. Change values of Mixture Compaction Pile's SRR according to granular materials showed similar patterns and stiffness of the composite soil is increased depending on the replacement ratio so SRR showed decreased patterns. Especially, when the replacement ratio is in 20~40%, it increase significantly. When the replacement ratio is over 40%, it increase slowly. When considering the economics, 30~40% replacement ratio is appropriate.

• Proceedings of the Korean Society of Surveying, Geodesy, Photogrammetry, and Cartography Conference
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• 2004.04a
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• pp.221-226
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• 2004

For comparing more than two images, the precise geometric corrections should be preceded because it necessary to eliminate systematic errors due to basic sensor information difference and non-systematic errors due to topographical undulations. In this study, we did sensor modeling using satellite sensor information to make a basic map of change detection for artificial topography. We eliminated the systematic errors which can be occurred in photographing conditions using GCP and DEM data. The Kompsat EOC images relief could be reduced by precise rectification method. Classifying images which was used for change detections by city and forest zone, the accuracy of the matching results are increased by 10% and the positioning accuracies also increased.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.11 no.4
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• pp.163-170
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• 1991

The 3 dimensional point positioning from SPOT imagery is performed by bundle adjustment methods of analytical and digital photogrammetry, and need the precise determination of image coordinates and accurate coordinates of ground control points. In this study, the authors analysed the digitized planimetric accuarcy and height accuracy of topographic maps in comparison with accurate coordinates by coordinates resulted by bundle adjustment in each cases between different acquisition method of ground control point coordinates and formats of SPOT imagery.

• Proceedings of the KSRS Conference
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• 2002.10a
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• pp.664-669
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• 2002

Intertidal zone (tidal flat) is a place which is sometimes dry and sometimes wet depending on the tidal rhythm. Direct measurement of topography in the intertidal zone is very difficult to be achieved. The interface between wet and dry parts in the tidal flat, which can be identified from near infrared band of satellite image, is a 'depth contour' which corresponds to the sea level at the time of satellite pass. Aquisition of topography data in tidal flat is possible by combining various techniques such as (1) identification of the interface between wet and dry parts, (2) GCP correction of satellite image, and (3) realtime prediction of sea level elevation at the time of satellite pass. The algorithm was successfully applied in obtaining topography (bathymetry) data in the intertidal zone of Asan Bay in the west coast of Korea from 26 satellite images. The method is expected to be very efficient in making bathymetry data base in the western and southern parts of Korea where tidal flats are well developed in wide regions.

• Proceedings of the KSRS Conference
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• 2008.10a
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• pp.11-13
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• 2008

This study proposes the method to use existing digital maps as one of the technologies to exclude individual differences that occur in the process of manually determining GCP for the geometric correction of KOMPSAT images and applying it to the images and to automate the generation of ortho-images. It is known that, in case high-resolution satellite images are corrected geometrically by using RPC, first order polynomials are generally applied as the correction formula in order to obtain good results. In this study, we matched the corresponding objects between 1:25,000 digital map and a KOMPSAT image to obtain the coefficients of the zero order polynomial and showed the differences in the pixel locations obtained through the matching. We performed proximity corrections using the Boolean operation between the point data of the surface linear objects and the point data of the edge objects of the image. The surface linear objects are road, water, building from topographic map.

• 제어로봇시스템학회:학술대회논문집
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• 2001.10a
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• pp.49.3-49
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• 2001

In 1994 Adelman´s pioneer work demonstrated that deoxyribonucleic acid (DNA) could be used as a medium for computation to solve mathematical problems. He described the use of DNA based computational approach to solve the Hamiltonian Path Problem (HPP). Since then a number of combinatorial problems have been analyzed by DNA computation approaches including, for example: Maximum Independent Set (MIS), Maximal Clique and Satisfaction (SAT) Problems. In the present paper we propose a method of solving another classic combinatorial optimization problem - the eraph Coloring Problem (GCP), using specifically designed circular DNA plasmids as a computation tool. The task of the analysis is to color the graph so that no two nodes ...

• Journal of the Korean Association of Geographic Information Studies
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• v.5 no.4
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• pp.86-92
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• 2002

The feasibility of counting number of small vessels and position in Korean waters using the panchromatic imageries derived from the IRS-1C was tested. The parameters for interpretation of satellite's imageries of small vessels were location(position), size, shape, shadow, tone, texture and pattern, height and depth, situation and association with other vessels. The position of small vessels in the sea without GCP(ground control point) was considered to be inclusive in the satellite imagery with 35 km semi-diameter, denoting rough geographical position of the vessel. The size of vessel was measured by length from stem to stern of the vessel, distinguished by following wave on the surface water. Offshore fishing vessels were separated from merchant ships by their length smaller than 100 m. The shape of vessels on panchromatic imagery of IRS-1C appeared just streamline. In case of clouds which were similar to the shape of small vessels, we were able to distinguish between vessel and cloud by shadow of cloud in the water surface. The tone of sea surface was dark black while small vessel appeared bright white. Small vessel was distinguished from the rough texture of the sea surface and the regular pattern of the waves with white capes when weather was not so good. The situation of the fishing activity was estimated by information of fishing method related to the fishing boat such as the pair trawl in the Yellow Sea.