• Journal of The Geomorphological Association of Korea
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• v.19 no.4
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• pp.139-155
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• 2012

Most of previous landform classification methods using DEM compares the values between the center of the cell and the surrounding cells, which in turn, greatly depends on analysis scale. To overcome the problem of scale-dependency, a new classification scheme is developed, which is called "Geomorphons". Unlike the traditional approaches using DEM, Geomorphons is the way which compares the level with other cells against the criteria cell. As a pilot study, we classify the landforms of Pyeongchang-Gun in Korea. Then, we compare the result with the other methods such as Topographic Position Index. Through the systematic analysis, we obtain the following findings. First, Geomorphons can reduce the time for the classification of landforms because of using unsupervised classification. Second, Geomorphons is little dependent on change in the scale, which can provide a pilot tool for reconnaissance study for covering large area.

• Spatial Information Research
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• v.18 no.5
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• pp.13-26
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• 2010

In this paper, a dynamic variable window-based topographical classification method is proposed which has the changeable classification units depending on topographical properties. In the proposed scheme, to im prove the classification efficiency, the unit of topographical classification can be changeable dynamically according to the topographical properties and repeated patterns. Also, in this paper, the classification efficiency and accuracy of the proposed method are analyzed in order to find an optimal maximum decision window-size through the experiment. According to the experiment results, the proposed dynamic variable window-based topographical classification method maintains similar accuracy but remarkably reduce computing time than that of a fixed window-size based one, respectively.

• Journal of the Korean Geographical Society
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• v.36 no.2
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• pp.81-92
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• 2001

본 연구의 목적은 지형요소의 GIS Database 구축을 위한 전산화된 지형분류도 제작방안을 제시하는 것이다. 지형요소 전산화는 지형요소의 분류, 지형요소의 코드화, 범례화, 심볼의 제작, 마지막으로 지도화의 과정을 통하여 완성된다. 지형분류는 지형요소의 공간적 분포와 형태, 지형형성과 발달에 영향을 미치는 자연환경체계와 지형형성기구의 역할을 고려하며, 동적인 지형형성과정과 이 과정을 통해 물질관계를 파악할 수 있도록 하였다. 지형분류도는 1: 25,000 축적에 표현 가능한 지형요소를 나타낼 수 있도록 고려하였다. 지형요소들의 지도화 되었을 때는 시.공간적인 관계를 통해 지형환경체계가 인식되도록 하였다. 지형요소들은 GIS에서 Layer단위로 입력되어야 하기 때문에 Data Feature의 성격을 점.선.면으로 분류하여 지형요소의 형상을 범례로 만들었다. 지형요소 범례는 지형의 형태, 물질 그리고 성인을 고려하여 지형요소를 상징화할 수 있도록 설계하였다.

• Journal of Korean Society for Geospatial Information Science
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• v.19 no.2
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• pp.9-17
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• 2011

For the exact status of the land such as land cover classification and land use classification, feature classification system has been utilized in several organizations and agencies. However, those classification systems are limited to detection of land change and it's also not suited for the extraction of land changed. In this study, we would proposed a standard feature classification system which presents both in natural and artificial change of land effectively. Based on comparison and analysis of domestic and foreign relevant feature classification system, we proposed a standard feature classification system. In order to validate the applicability of the proposed feature classification system, we evaluated the accuracy with using automatic feature classification based on supervised classification and pre-knowledge hierarchical classification.

• Proceedings of the Korea Information Processing Society Conference
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• 2010.11a
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• pp.79-82
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• 2010

본 논문에서는 항공 라이다 데이터로부터 지형의 유형을 분류하는 과정에서 지형적 특성에 따라 분류에 사용하는 판정 윈도우의 크기를 가변적으로 조정하여 적용시키는 가변형 판정 윈도우를 이용한 지형 분류 기법을 제안하였다. 또한 실험을 통하여 가변형 판정 윈도우를 이용한 지형 분류 기법의 시간효율과 정확도를 분석하였다. 실험 결과에 따르면 제안된 가변형 판정 윈도우를 이용한 지형 분류 기법은 지형 분류에 사용되는 판정 윈도우의 개수를 줄여 지형 분류의 속도를 향상시켰기 때문에 빠른 분류 속도가 필요한 재해 피해 현황을 파악하기 위한 시스템에 적용 할 수 있을 것으로 기대된다.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.28 no.1
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• pp.133-142
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• 2010

To monitor composition and change of the national land, intelligent topographical classifier which enables accurate classification of land-cover types from airborne LiDAR data is highly required. We developed a topographical classifier development support system cooperating with da1a mining tool WEKA to help users to construct accurate topographical classification systems. The topographical classifier development support system has the following functions; superposing LiDAR data upon corresponding aerial images, dividing LiDAR data into tiles for efficient processing, 3D visualization of partial LiDAR data, feature from tiles, automatic WEKA input generation, and automatic C++ program generation from the classification rule set. In addition, with dam mining tool WEKA, we can choose highly distinguishable features by attribute selection function and choose the best classification model as the result topographical classifier. Therefore, users can easily develop intelligent topographical classifier which is well fitted to the developing objectives by using the topographical classifier development support system.

• Proceedings of the KGS Conference
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• 2004.05a
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• pp.38-38
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• 2004

효율적 인 국토환경 관리와 지속 가능한 생태자원의 보존을 위해서는 지형 및 토양의 공간적인 분포특성과 그것이 각종 자연 및 인문현상들과 가지는 상관성에 대한 파악이 선행되어야 한다 기존의 지형분류법은 대부분 지형형성과정 혹은 지형의 형태의 분류에 치중하여, 그 결과가 지표면에서 나타나는 생태학적 현상들과의 관련성을 파악하기 어려운 단점이 있다. (중략)

• Proceedings of the Korean Association of Geographic Inforamtion Studies Conference
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• 2010.09a
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• pp.119-125
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• 2010

본 연구에서는 항공 라이다 데이터로부터 지표의 유형을 분류하는 과정에서 필요한 처리시간을 감소시켜 보다 효율적인 지형 분류가 가능하도록 타일 단위의 샘플링을 이용한 지형 분류 기법을 제안하였다. 또한 실험을 통하여 샘플링 정도에 따라 정확도와 시간효율을 비교분석하여 최적의 샘플링 정도를 제시하였다. 본 연구에서 제안한 타일 단위의 샘플링을 이용한 지형 분류기법을 이용해 자연재해내 도시 구조 변화 등의 지형정보의 변화를 탐지하기 위한 모니터링 목적으로 활용할 경우에 지형분류의 정확도 손실을 최소화하면서 빠른 처리가 가능하기 때문에 실시간 서비스가 가능해 질 수 있다.

• Journal of Korean Society for Geospatial Information Science
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• v.18 no.2
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• pp.29-33
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• 2010

The purpose of LiDAR ground classification is to archive both goals which are acquiring confident ground points with high precision and describing ground shape in detail. In spite of many studies about developing optimized algorithms to kick out this, it is very difficult to classify ground points and describing ground shape by airborne LiDAR data. Especially it is more difficult in a dense forested area like Korea. Principle misclassification was mainly caused by complex forest canopy hierarchy in Korea and relatively coarse LiDAR points density for ground classification. Unfortunately, a lot of LiDAR surveying performed in summer in South Korea. And by that reason, schematic LiDAR points distribution is very different from those of Europe. So, this study propose enhanced ground classification method considering Korean land cover characteristics. Firstly, this study designate highly confident candidated LiDAR points as a first ground points which is acquired by using big roller classification algorithm. Secondly, this study applied weighted gradient kernel(WGK) algorithm to find and include highly expected ground points from the remained candidate points. This study methods is very useful for reconstruct deformed terrain due to misclassification results by detecting and include important terrain model key points for describing ground shape at site. Especially in the case of deformed bank side of river area, this study showed highly enhanced classification and reconstruction results by using WGK algorithm.

• Journal of Korea Water Resources Association
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• v.37 no.1
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• pp.1-11
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• 2004

The purpose of this study consists in introducing and examining the previous river classification systems applicable to the river improvement technique including geomorphological considerations, and developing a new system using the geomorphological criteria which represent the morphology of rivers. A newly developed system uses the channel reach as a classifying unit which is delineated by upstream and downstream tributaries. It adopts three basic geomorphological criteria for classification: 1) valley-floor width index(VI) reflecting the confinement of the channel in the valley, 2) sinuosity(P) which expresses the channel planform, and 3) bed material($d_{50}$). The system is composed of 24 stream types. Concerning every stream type, valley forms, principal bed forms and fluvial processes with disturbance elements are briefly presented. Finally, the applicability of this system to the Chungmi Stream and the Imjin River data in comparison with that of Rosgen system is examined.