• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.13 no.2
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• pp.141-151
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• 1995

In generating DTM as basic data to GIS, the use of existing map is difficult to aquire current data and the method using airphotos needs cost for stereoplotting and ground control surveying. So, the method of DTM generation by satellite imagery is promising because satellite is able to observe wide area at once. In this study the program for SPOT bundle adjustment and image matching based on Coarse to Fine method is developed and various image enhancement algorithm is used for more accurate DTM generation and also evaluation of accuracy was carried out. Further more, orthophoto, a bird's eye-view, contour map producing, net-work analysis and terrain analysis were performed for GIS applications using generated DTM in this study. Generated DTM using SPOT stereo imagery is useful for GIS applications such as automated mapping, facility management, national geographic information system. Moreover developed automatic DTM generation pro-gram is studied, tested and verified more to be applicable to all the area.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.28 no.3
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• pp.299-304
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• 2010

Depending on the progress of the surveying and information processing technology, the rapidly developing field of spatial information and the 3D real world spatial information for a variety of content on the computer was able to easily access. In this research, to study on the spot or to use aerial photographs to measure trees of the acquired data, calculate the trees height, forest area and capacity, determine the distribution of the density of acquired points in the forest and analyze accurate and objective information was acquired. The United States, Canada and so on through the capacity of trees biomass, forest resource analysis, time series monitoring, wildfire behavior modeling and applied research and has been declared. During worldwide is increasing interest in forest resources. In nationally, extensive research and analysis of the forest consists of the correct management and protection of forest resources to be effective.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.17 no.4
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• pp.421-429
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• 1999

It is estimated that, in the twenty-first century, 70％ of global citizens will live in urban areas. This accelerated urbanization will require a greater need for the building DEM and orthoimagery along with Geographic Information System for urban management. The building DEM requires the detection of outlines showing building shapes. To do this, automatic and semiautomatic building extractions are usually used. However, in cases where automatic extraction is performed directly from the aerial images, accurate building outline extraction is very difficult because of shadow, roof color, and neighboring trees making it hard to discern building roofs. To overcome this problem semiautomatic building extraction was suggested in this paper. When a roof texture was homogeneous, building outline detection was performed by mouse-clicking on a part of the roof. To construct the building outlines when the texture was not homogeneous, a computer program was developed to search out corner points by clicking spots near corner points. The building DEM was generated by taking into account building outlines and heights calculated by image matching.

• Journal of Korean Society for Geospatial Information Science
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• v.17 no.4
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• pp.45-51
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• 2009

Different countries around the world, using their traditional culture as a background, are promoting new changes and reformation in development and publicity method of cultural contents to promote national interests and to increase their competitiveness. Also, as the citizen's standard of living and quality of living goes up, various demands for the enjoyment of traditional culture goes up accordingly as well. As the cultural assets environment become more complicated and diverse, there is a need for systematic management and preservation plan. Keeping these viewpoints in mind, the geo-spatial information provision service using the web provides various forms of services such as satellite imagery, terrain, and 3D viewing, enabling the user to gain concrete spatial information on specific areas. The geo-spatial information using 3D modeling is done only in limited spaces because of construction expenses or difficulties in management and maintenance. In this thesis, I would like to propose Effective method for the GoogleEarth Uploading through simplification of 3D object for the publicity of traditional buildings and Cultural Resources and Tourist Attractions.

• Ecology and Resilient Infrastructure
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• v.6 no.4
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• pp.287-294
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• 2019

This study investigated longitudinal changes in riverbed materials properties and temporal alteration of river channel geomorphology in the Geum River basin, where two multipurpose dams(Yongdam Dam and Daecheong Dam) were built in upstream area. We carried out grain size distribution analyses and measured soil organic matter contents of riverbed materials taken at the upper and lower sites of the two large dams. We also estimated the channel width, bar area and vegetation encroachment using the oldest map and aerial photographs taken before and after the construction of the dams. The results can contribute to increasing understandings of dam induced habitat alteration in river ecosystem.

• Proceedings of the KSR Conference
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• 2009.05a
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• pp.1003-1009
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• 2009

The Spatial Image contents of Geomorphology 3-D environment is focused by the requirement and importance in the fields such as, national land development plan, telecommunication facility management, railway construction, general construction engineering, Ubiquitous city development, safety and disaster prevention engineering. The currently used DEM system using contour lines, which embodies geographic information based on the 2-D digital maps and facility information has limitation in implementation in reproducing the 3-D spatial city. Moreover, this method often neglects the altitude of the rail way infrastructure which has narrow width and long length. This As the results, We confirmed the solutions of varieties application for railway facilities management using 3-D spatial image contents and database design. Also, I suggested that U-city using railway modeling about matching methods of high density elevation value using 3-D aerial photo with laser data are best approach for detail stereo modeling and simulation.

• Journal of the Korean Association of Geographic Information Studies
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• v.6 no.3
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• pp.83-94
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• 2003

All the urban planning process require land use informations, which should be obtained after through intensive investigation and accurate analysis about the past and current situations and conditions of a city. Until now, the generation of land use informations from remotely sensed imagery has had many limitation because of its spatial resolution. It is now expected that the availability of high resolution satellite imagery whose spatial resolution less than 10m will reduce these limitations. For the purpose of urban growth monitoring we must first establish a urban land use classification nomenclature. In this study, we would like to establish a land use nomenclature for land use classification using remotely sensed data, especially using KOMPSAT EOC imagery.

• Proceedings of the Korea Water Resources Association Conference
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• 2012.05a
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• pp.612-612
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• 2012

최근 GIS를 이용하여 수리 수문학적인 지형인자를 생성할 수 있는 Arc Hydro 등의 다양한 GIS 기반 툴들이 개발되어 왔다. 예를 들어 Arc Hydro는 격자형 고도자료인 수치표고모델(Digital Elevation Model)을 통해 수자원에서 필요로 하는 유로연장, 유역경사 등의 지형인자를 산정할 수 있는 기능을 제공해 주고 있다. 하지만 기존의 GIS 기반 툴에서는 Manning의 평균유속 공식 등 하천수리학에서 매우 중요한 인자인 하천경사를 하천망을 따라 산정하고 표출하는 기능이 부족하였다. 또한 하천경사 산정에 사용되는 여러 GIS 툴을 통해서 제공되는 셀 경사 등 지형인자들의 기계적인 적용으로 정확한 하천경사의 산정에 문제가 있어왔다. 본 논문은 이러한 지형인자들의 적용성을 평가하고 다양한 이론적 하천경사 산정법을 GIS 상에 적용하여 상호 비교하여 최적화된 하천경사 산정방법을 제시하고자 한다. 연구 대상유역으로는 제주도를 선정하였으며, 대상 하천은 Arc Hydro를 이용하여 산정된 하천망의 형태를 수자원관리정보시스템(WAMIS), 위성사진 등과 비교한 후 시범 하천(한천)을 선택하여 여러 하천경사 산정법을 적용해 보았다. 적용된 산정법은 총 4가지로 첫 번째 방법은 수치표고모델의 주변 표고를 고려하여 산정된 기울기를 Arc Hydro를 이용하여 산정된 하천을 따라 산술평균하는 방법이며, 나머지 3가지 방법은 하천망을 따라 흐름방향의 거리와 수치표고모델의 표고를 수집한 후에 단순경사방법, 등면적경사방법, 등가경사방법에 적용하는 방법이다. 산정된 하천경사를 상대비교를 하여 대상유역에 대한 비교검토를 실시하였다. 모든 과정은 프로그램 개발을 통해 자동화 시켜 향후 다른 유역의 적용과 변화 가능한 지형정보를 신속하고 효율적인 예측을 가능할 수 있도록 하였다. 또한 주어진 하천망의 두 지점 사이의 종방향 경사를 산정하여 표출하는 기능을 추가하여 하천 경사의 표출방식을 향상시켰다. GIS를 이용하여 산정되어진 하천경사의 적용성이 충분하다면 Manning의 평균유속 공식에 적용할 수 있을 뿐만 아니라 다양한 하천분석이 용이해 질 것으로 예상된다.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.35 no.3
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• pp.195-202
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• 2017

Ortho images created by aerial photogrammetry have been used in large areas but they are uneconomical for small areas and continuous change observation. The drones have been developed for military purposes, and recently they are being used crop management and analysis, broadcast relay, meteorological observation and disaster investigation and so on. Also there were a lot of studies of expensive commercial drone. In this paper, lower price self-assembly drone usable for in small areas, Obtained images and produced Orthomosaic and DSM using mission planner which is a normal digital camera and open source program, and postprocessing was used Pix4d software. GCP errors are X-coordinate 3.4cm, Y-coordinate 2.4cm, Z-coordinate 4.2cm. It seems like the self-assembly drone can be used for various fields.

• Proceedings of the Korea Water Resources Association Conference
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• 2011.05a
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• pp.325-325
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• 2011

자연과 함께하는 하천복원 기술개발(Ecoriver21) 연구단에서 진행 중인 홍수터 수목관리 기술 개발 과제에서는 국내하천 흐름저항 산정기법을 개발하기 위해 2006년부터 2009년까지 총 27개 시험하천의 실측자료를 이용한 조도계수를 산정하였다. 2010년에는 18개 시험하천을 추가로 운영하여 최종적으로 총 45개 하천의 조도계수를 산정하고자 한다. 조도계수 계산에 필요한 자료는 모두 현장에서 직접 측정하였으며 이를 위해 넓은 범위의 수위자료를 획득할 수 있는 홍수기 이전에 수위계를 설치하였고, 유량 측정, 하천 단면 측량, 하상재료 입경분석 등을 통하여 유량 변화에 따른 조도계수 분석, 하상재료 크기별 조도계수 변화 분석, 조도계수 경년변화 분석 등의 연구를 진행하였다. 분석 결과 대부분의 하천은 유량이 증가함에 따라 조도계수가 감소하는 경향을 보였고 특정한 유량 범위에서 수렴하였다. 유량에 따른 조도계수 변화 폭은 하상재료의 입경 크기가 클수록 심하였다. 산지 거석하천인 내린천 왕성동 지점의 경우 0이 287.8 mm로 조사 지점 중 하상재료의 크기와 유량에 따른 조도계수 변화 폭, 수렴되는 조도계수 값이 가장 컸다. 하상재료 입경 크기 $D_{50}$을 기준으로 2 mm이하인 모래하천의 경우에는 유량이 증가함에 따라 조도계수가 감소하다가 고유량에서 다시 증가하는 경향을 보였다. 조도계수 경년변화를 분석한 평창강 방림 지점과 만경강 고산 지점의 결과는 비교적 큰 차이를 나타내지 않았고, 한강 본류의 배수영향을 받는 옥동천 옥동, 법천천 법천 지점의 경우 배수 상황 발생 시 다른 지점과 달리 상당히 복잡한 양상을 나타내었다. 본 연구에서는 지금까지 진행된 국내하천의 조도계수 분석 자료를 종합하여 조도계수 자료집을 발간할 계획이며, 조도계수 자료집에는 각 지점의 수위 및 유량 실측자료, 하상재료 입경 크기, 지점 특성, 사진 자료 등이 포함될 예정이다.