• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.18 no.1
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• pp.51-57
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• 2000

With the emergence of laser mapping systems, higher resolution DTM of urban area can be acquired and can be used to generate precise orthoimage. But, when the conventional orthoimage generation methods are applied to the area containing features with height difference such as cliffs, bridges, banks. elevated highways and buildings, they cause problems such as occlusion and double mapping. Therefore, this study proposes a new algorithm by modifying and refining conventional orthoimage generation methods. With this algorithm, areas which have occlusion are detected from the base image using camera orientation parameters and DTM. Also, detected areas are restored using alternative images which does not have occlusion in that area. This study can be distinguished from the other studies in the aspects that the proposed algorithm in this paper doesn't need information on building and that uses DTM data and orientation parameters.

• Journal of Korean Society for Geospatial Information Science
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• v.2 no.1 s.3
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• pp.73-80
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• 1994

Most terrain information have been generally acquired by map. Because the map presents the real terrain, not by real figure but by contours, geometric figures, symbols, texts, and colors, it is not easy to interpret the real terrain by map. For this reason, aerial photos or terrestrial photos also have been used sometimes in the terrain analysis. But photos have geometrical displacement caused by the position of camera at the exposition time and the relief of the object. So, for accurate posional analysis, orthophoto maps produced by optical rectifier have been used. But, it is hard to produce orthophoto map by optical rectifier and the process is so slow. This study aims to present an accurate and rapid method to produce orthophoto map by generating digital elevation model from stereo aerial photos on common computer using the digital photogrammetric technique and producing orthophoto map digitally using the digital elevation model.

• Journal of Korean Society for Geospatial Information Science
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• v.24 no.3
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• pp.3-9
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• 2016

UAV(unmanned aerial vehicle) can quickly produce orthoimage with high-spatial resolution and DSM(digital surface model) at low cost. However, vertical and horizontal positioning accuracy of orthoimage and DSM, which are obtained by UAV, are influenced by image processing techniques, quality of aerial photo, the number and position of GCPs(ground control points) and overlap in flight plan. In this study, effects of overlap and the number of GCPs are analyzed in orthoimage and DSM. Positioning accuracy are estimated based on RMSE(root mean square error) by using dataset of nine pairs. In the experiments, Overlaps and the number of GCPs have influence on horizontal and vertical accuracy of orthoimage and DSM.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.38 no.6
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• pp.645-653
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• 2020

Recently studies on how to use the UAV (Unmanned Aerial Vehicle) are actively being conducted, and the National Geographic Information Institute published the 『Work Guidelines for Public Surveying of Unmanned Aerial Vehicles』. However, the guidelines do not provide the optimum shooting conditions required for each application. In this study, we tried to find the suitable shooting conditions for the production of 3D (Three-dimensional) spatial information and orthophoto. To this end, 45 experiments were conducted by various altitudes, overlaps, and camera angles within an above ground level of 150m. For evaluating the 3D modeling by shooting conditions, point densities of 9 verification areas were analyzed, and to evaluate the orthophotos, 1/1,000 digital maps were compared. Considering the quality of the output and the processing time for precise 3D construction, an altitude of 50m, an overlap of 70~80%, and a camera angle of 80~90° are suitable as shooting conditions, and an altitude of 100m and camera angle of 80~90° are suitable for orthophoto generation.

• Journal of the Korean Institute of Traditional Landscape Architecture
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• v.31 no.1
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• pp.59-70
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• 2013

This study was to suggest cultural landscape preservation, value creation, as well as utilization plan to help landscape development of Hahoe village by identify the existence of Okyeonsipyeong(玉淵十詠) natural features, which were set around Buyongdae(芙蓉臺) in Hahoe Village by Seoae(西崖) Ryu, Seongryong(柳成龍), and understanding their characteristics and meanings of natural features and meanings. Based on the writings of "Okyeonseodanggi" and "Okyeonsipyeong", the major results of this study are as belows. 'Okyeon(玉淵)' letters carved on the rocks, also known as the name of pavilion in Okyeonjeongsa(玉淵精舍), is the center of Okyeonsipyeong that symbolizes the enlightenment of clean noble man, as well as the symbolic locational expression of studying room. One of Okyeonsipyeong, 'Wansimjae', is assumed to be the name from the combination of two Buddhist names, 'Wanjeok(玩寂)' and 'Seshim(洗心)', 'Dangho(堂號)', lined on both sides with Wonlakjae, the residence of Seoae, as the center. Wansimjae is after all the natural feature indicating the overall Okyeonjeongsa as the core of Okyeonsipyeong with west edge Gyeomamjeongsa(謙巖精舍). Among ten Okyeonsipyeong natural features, Wansimjae(玩心齋), Ganjukmun(看竹門), Gyeomamsa(謙菴舍), Dalgwandae(達觀臺), Ssangsongae(雙松厓), and Dohwacheon (桃花遷) are on the right side of the stairway from Okyeonjeongsa to Gyeomamjeongsa, while Chuwoldam(秋月潭), Neungpadae(凌波臺), Gyeseonam(繫船巖), and Jijuam(砥柱巖) are on the road to the cliff under river cliff in Buyongdae as well as to the dock, and all are located within 500m radius close and diameter area. As the results of lexeme and context analyses of Okyeonsipyeong poet, they are mainly about Confucian teachings symbolizing the constancy of the classical scholar including ego becoming one with the nature and back to the nature, unworldliness and farsighted view, transcendence and seclusion, as well as integrity spirit. In Dohwacheon and Gyeomamsa poets, there is Tao characteristics and brotherhood that pursue fairylands such as Mooreungdowon(武陵桃源). To create tourism brand and landscape of Okyeonsipyeong, it is necessary to prepare storytelling plans including the letters carved on the rocks introduction in Buyongdae area, and also synopsis of the Silgyeongsusang musical, 'Buyongjiae(芙蓉之愛)' that is related to 10 natural features. In addition, the related plans of the experience road from Gyeseonam, which is the boat stop in Buyongdae, to Ganjukmun of Okyeonjeongsa, and again to viewing routes on the stairways to Gyeomamjeongsa using boats are necessary. For preliminary preservation and maintenance plans, the safety of the stairway from Okyeonjeongsa to Gyeomamjeongsa should be secured, the rock inscription should be preserved, landscape interpretation plates should be installed, trees and shrubs around Dohwacheon rock inscription should be removed, Dalgwandae letters carved on the rocks should be restored, and the bamboo forest outside Ganjukmun as well as Prunus persica plantation around Dohwacheon should be pointed out.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.38 no.4
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• pp.363-373
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• 2020

During last decades numerous studies generating orthoimage have been carried out. Traditional methods require exterior orientation parameters of aerial images and precise 3D object modeling data and DTM (Digital Terrain Model) to detect and recover occlusion areas. Furthermore, it is challenging task to automate the complicated process. In this paper, we proposed a new concept of true orthoimage generation using DL (Deep Learning). DL is rapidly used in wide range of fields. In particular, GAN (Generative Adversarial Network) is one of the DL models for various tasks in imaging processing and computer vision. The generator tries to produce results similar to the real images, while discriminator judges fake and real images until the results are satisfied. Such mutually adversarial mechanism improves quality of the results. Experiments were performed using GAN-based Pix2Pix model by utilizing IR (Infrared) orthoimages, intensity from LiDAR data provided by the German Society for Photogrammetry, Remote Sensing and Geoinformation (DGPF) through the ISPRS (International Society for Photogrammetry and Remote Sensing). Two approaches were implemented: (1) One-step training with intensity data and high resolution orthoimages, (2) Recursive training with intensity data and color-coded low resolution intensity images for progressive enhancement of the results. Two methods provided similar quality based on FID (Fréchet Inception Distance) measures. However, if quality of the input data is close to the target image, better results could be obtained by increasing epoch. This paper is an early experimental study for feasibility of DL-based true orthoimage generation and further improvement would be necessary.

• Journal of the Korean Institute of Traditional Landscape Architecture
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• v.31 no.4
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• pp.70-83
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• 2013

To widen prospect of villa as Korea traditional garden, the result of the research about constructional characteristics of Seogo-jeongsa and Sameun-jeong of Yeoju Lee family at Toero-ri, Miryang-si, Gyeongsangnam-do, Korea, is abstracted as below. Seogo-jeongsa(西皐精舍) and Sameun-jeong(三隱亭) was intended to practise retirement with sense of unity with the head residence, since Seogo-jeongsa was 340m far and sameun-jeong was 630m far away from head residence, which set within 1km. Although Seogo-jeongsa's basic prop, Sameun-jeong's timber, which are both from designer's pen name and head residence name, "Hangjae(恒齋)" and "Yongjae(庸齋)," and Hanseoam have each different exposure, it is homogeneous as space configurational side in order to optimize the gaze leading effect and appreciated domestic trees from the pond, which is center of the garden and the significant facility. Method of direction of Seogo-jeongsa's Hwalsudang(活水塘) and Sameunjeong's pond of Sameun-ji(三隱 池) gets attention by distinction. Especially, directing of 3 step water flow from behind to front and traditional pond method, called Bangji-Bangdo(方池方島), were very unique that any other place can be found. Also, the middle islet on the pond at both villa, which isn't more supper, but more for the symbolic molding that seek a stone pagoda(石假山), is more interesting directing method as considering the relationship of the 3 stone pagoda imageries on the surface of Ghwayukchon(果肉泉) At the same time, Seogo-jeongsa and Sameun-jeong shows very different characteristics from traditional villa that adopted both domestic trees and foreign trees. Particularly, it is extremely exceptional case to plant vigorous needleleaf tree, such as Chamaecyparis pisifera, C. obtusa, Pinus bungeana, P. palustris, Sciadopitys verticillata, Metasequoia glyptostroboides and Cedrus deodara, on Sameun-jeong. Moreover, adopting foreign wild needleleaf trees for landscaping trees, such as a Torreya nucifera, Taxus cuspidata, P. parviflora, and foreign landsacping trees, such as P. bungeana, Cryptomeria japonica and C. obtusa tells planting trend of the late Joseon dysnasty era. Also, as we can know from 2 Jipgyeong(集景), which is 'Seogo-jabyoung 17 young(西皐雜詠十七詠)', and 'Sameun-jeong 12 Gyoung(三隱亭十二景)' which are set on both villa, the intend to expand the garden area is strongly shown by the natural forest directing. As a result, Seogo-jeongsa and Sameun-jeong, located at Toero-li Miryang, are sharing the traditional Joseon dynasty era's custom, such as space and visual composition; however, it is different and attractive garden remains as a point of view of water directing, stone pagodas, and adopting foreign landscaping trees.

• (The) Research of the performance art and culture
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• no.36
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• pp.751-781
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• 2018

Task of circling the pagoda of Waljeongsa(Woljeongsa Tabdori) is the major intangible cultural heritage with representativeness and historical meaning as a Buddhism culture, one of the Buddhism folk plays, which was firstly played after the liberation. Woljeongsa Tabdori holds significant designation importance in terms of Buddhism folklore heritage with Korean unique tradition and identity of Gangwon-do province. Temples are demonstrating Tabdori nationwide but Woljeongsa Tabdori is the unique case that systematically inherits the culture based on the designation of being intangible cultural heritage. That is why it is needed to focus on the cultural and internal value of Woljeongsa Tabdori. Tabdori is the integrated symbol of Buddhism respect and worship to the Buddha and pagoda. It is hard to presume the originality of Woljeongsa Tabdori: given the history of Woljeonsa temple, it lies into Goguryeo traditional play and Bokhui(Pagoda circling folk play) in Silla era. It fits into the courtesy of Circumambulating Stupa considering Moon in Goguryo mural, background of Odaesan Hwaeom thought/tripitaka and essence of Octagonal 9-story stone pagoda. At the first stage of Tabdori, Buddhist musical instruments such as Buddhism temple bell, singing bowl, cloud-shaped gong and wooden-fish. However, later, Samhyeon Yukgak has been added and then, Boyeom and Bakpaljeongjinga were singing: it could be interpreted that it was a pure Buddhist ceremony but it has become to have traditional aspect and been spread to the public. The origin of Woljeongsa Tabdori is related to the explanation of Circumambulating Stupa that experiences the glory of the ending ceremony. When a temple has a rite, the Buddhists make an offering to the Buddha. At that time, Buddhist prayer, sermon and chant are followed. After the rite, the Buddhists are circling the pagoda with the monks while praying for Buddhist charity and making their own wishes. It prays not only going after death to Nirvana of the one but also national prosperity and the welfare of the people for peaceful reign. As the temple holds bigger rites, many Buddhists gather and the Tabdori was a success. The scene of circling the pagoda and making own wishes in line with the Buddhist sermon was solemn. The idea on changes and convergence of Woljeongsa Tabdori requires strategic inheritance to promote the transmission while maintaining the paragon and purpose of designating the cultural heritage and reviving its identity. Korean Tabdori was held in Buddha's birthday in April and the mid-autumn day. Tabdori is a memorial service type Buddhist ceremony that once the monk holds the Buddhist rosary, circles the pagoda and sings the great mind and charity of the Buddha, Buddhists follow the step, lighting the lantern, circling the pagoda and praying for the gentle and easy death. Transmission education of the successor, diversified approach of the expert's advice and discourse on the revival of the origin should be reinforced in phases.

• Proceedings of the Korean Society of Surveying, Geodesy, Photogrammetry, and Cartography Conference
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• 2007.04a
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• pp.191-196
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• 2007

본 연구에서는 변화탐지 기법을 통한 도심지 건축물의 판독가능성을 검토하기 위하여 항공사진 단영상 및 정사영상을 이용하여 영상정규화와 기하보정을 통한 image subtraction기법을 적용하여 변화 탐지를 실시하였다. 변화 탐지를 위한 임계값 설정에서 단영상 변화탐지는 임계값 90% 이상에서는 일정면적 이상의 변화지역이 뚜렷이 나타났으며 정사영상 변화탐지는 임계값 $70{\sim}80%$ 이상의 결과영상이 변화탐지에 적절한 것으로 나타났다. 단영상과 정사영상 변화탐지 결과를 필터링을 통해 일정면적 이하를 제거한 후 2002년 영상과 중첩하여 변화지역을 확인 하였다. 변화탐지 기법을 판독 작업에 활용한다면 판독 우선순위 결정에 많은 도움이 될 뿐만 아니라 영상의 종류와 필요에 따른 다양한 변화탐지 기법을 적용한다면 판독 작업에 많은 활용성을 기대할 수 있다.

• Journal of the Korean Society of Hazard Mitigation
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• v.4 no.4 s.15
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• pp.55-61
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• 2004

Rapid developments in sensor technologies now allow the generation of multi-source topographical data. For many applications, however, the geospatial information provided by individual sensors is not complete, precise, and consistent. To solve these inherent problems, additional diverse sources of complementary data can be used and fused. In this paper, the experiment was done for generation of 3D orthoimage data using LIDAR data and digital camera image. And the results show that 3D orthoimage can be used for the flood monitoring.