• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.37 no.1
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• pp.9-18
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• 2019

The intensity and the number of days of high temperature occurrence are also high and record heat occurred. In addition, the global warming phenomenon is intensifying globally, and especially in South Korea, the urban heat island phenomenon is also occurring due to rapid urbanization due to rapid industrial development. As the temperature of the city rises, it causes problems such as the comfort of the residential living and the cooling load. In this study, the cool roof performance is evaluated according to the roof color to reduce these problems. Unlike previous studies, UAV(Unmanned Aerial Vehicle) thermal infrared camera was used to obtain the surface temperature (white, grey, green, blue, brown, black) according to the rooftop color by remote sensing technique. As a result, the surface temperature of white color was $11{\sim}20^{\circ}C$ lower than other colors. Also air conditioning temperature of white color was $1.5{\sim}4.4^{\circ}C$ lower than other colors and the digital thermometer of white color was about $1.5{\sim}3.5^{\circ}C$ lower than other colors. It was confirmed that the white cool roof performance is the best, and the UAV and the thermal infrared camera can confirm the cool roof performa.

• Journal of Cadastre & Land InformatiX
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• v.49 no.1
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• pp.85-101
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• 2019

Recently, thank to the popularization of light-weight drone through the significant developments in computer technologies as well as the advanced automated procedures in photogrammetry, Unmanned Aircraft Systems have led to a growing interest in industry as a whole. Documentation, maintenance, and restoration projects of large scaled cultural property would required accurate 3D phenomenon modeling and efficient visual inspection methods. The object of this study verify on the accuracies achieved of 3D phenomenon reconstruction as well as on the validity of the preservation, maintenance and restoration of large scaled cultural property by UAS photogrammetry. The test object is cltural heritage(treasure 1324) that is the rock-carved standing Bodhisattva in Soraesan Mountain, Siheung, documented in Goryeo Period(918-1392). This standing Bodhisattva has of particular interests since it's size is largest stone Buddha carved in a rock wall and is wearing a lotus shaped crown that is decorated with arabesque patterns. The positioning accuracy of UAS photogrammetry were compared with non-target total station survey results on the check points after creating 3D phenomenal models in real world coordinates system from photos, and also the quantified informations documented by Culture Heritage Administration were compared with UAS on the bodhisattva image of thin lines. Especially, tests the validity of UAS photogrammetry as a alternative method of visual inspection methods. In particular, we examined the effectiveness of the two techniques as well as the relative fluctuation of rock surface for about 2 years through superposition analysis of 3D points cloud models produced by both UAS image analysis and ground laser scanning techniques. Comparison studies and experimental results prove the accuracy and efficient of UAS photogrammetry in 3D phenomenon modeling, maintenance and restoration for various large-sized Cultural Heritage.

• Journal of Cadastre & Land InformatiX
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• v.51 no.1
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• pp.111-124
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• 2021

Recently, Interest in the restoration and 3D reconstruction of cultural properties due to the fire of Notre Dame Cathedral on April 15, 2019 has been focused once again after the 2008 Sungnyemun fire incident in South Korea. In particular, research to restore and reconstruct the actual measurement of cultural properties using LiDAR(Light Detection and ranging) and conventional surveying, which were previously used, using various 3D reconstruction technologies, is being actively conducted. This study acquires data using unmanned aerial imagery of UAV(Unmanned Aerial Vehicle), which has recently established itself as a core technology in the era of the 4th industrial revolution, and the existing CRP(Closed Range Photogrammetry) and terrestrial LiDAR scanning for the Recumbent Buddha of Unju Temple. Then, the 3D reconstruction was performed with three fusion models based on SfM(Structure-from-Motion), and the reproducibility and accuracy of the models were compared and analyzed. In addition, using the best fusion model among the three models, the relationship with the Polar Star(Polaris) was confirmed based on the real world coordinates of the Recumbent Buddha, which contains the astronomical history of Buddhism in the early 11th century Goryeo Dynasty. Through this study, not only the simple external 3D reconstruction of cultural properties, but also the method of reconstructing the historical evidence according to the type and shape of the cultural properties was sought by confirming the historical evidence of the cultural properties in terms of spatial information.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.40 no.5
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• pp.421-428
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• 2022

The earthwork is a core process of all constructions, and compaction measurement of earthwork play an important role in improving productivity. The analog tests such as Plate Bearing Test and Sand-cone occupy current compaction measurement techniques. Due to advanced 4th Industrial Revolution, research on analog tests combined smart construction technology are actively conducted. DCPT (Dynamic Cone penetration Test), simpler and faster than conventional tests, has recently on rise. However, it is also an analog that measures data manually and has several disadvantages such as history management and data verification. The IoT-based DCPT system developed in this study combines digital wire sensors, mobile phones, and Bluetooth with conventional DCPT. Compare to conventional test methods, IoT-based DCPT has advantages such as performance time, single-person measurement, low cost, mobile-based management, and real-time data verification. In addition, a test bed was built to verify IoT-based DCPT. The test bed was built under similar conditions to the actual earthworks site through roller equipment. DCPT data obtained from 322 stations. As a result, IoT-based DCPT showed good performance, and the test bed was also showed stable results as the compaction was carried out.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.39 no.6
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• pp.609-618
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• 2021

The spread and damage of COVID-19 are putting significant pressure on the world, including Korea. Most countries place restrictions on movement and gathering to minimize contact between citizens and these policies have brought new changes to social patterns. This study generated traffic volume data on the scale of a road network using taxi movement data collected in the early stages of the COVID-19 third pandemic to analyze the impact of COVID-19 on movement patterns. After that, correlation analysis was performed with the data of confirmed cases in Daegu Metropolitan City and Local Moran's I was applied to analyze the effect of spatial characteristics. As a result, in terms of the overall road network, the number of confirmed cases showed a negative correlation with taxi driving and at least -0.615. It was confirmed that citizens' movement anxiety was reflected as the number of confirmed cases increased. The commercial and industrial areas in the center of the city confirmed the cold spot with a negative correlation and low-low local Mona's I. However, the road network around medical institutions such as hospitals and spaces with spatial characteristics such as residential complexes was high-high. In the future, this analysis could be used for preventive measures for policymakers due to COVID-19.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.37 no.1C
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• pp.1-7
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• 2012

At the industrial work site, the manufacturing process is being automated to improve work efficiency. However, it is often difficult to automate the entire manufacturing process, and there are spaces in which workers there are constantly exposed to danger. To protect such workers from the danger, this paper studied a worker safety management system for the industrial work site which uses a location recognition system and which is based on the Ubiquitous-Wireless Sensor Network (U-WSN). Using wireless signals, the distance between two devices can be measured and the location of a worker can be calculated using triangularization in 3-D. But at the industrial work sites where there are a lot of steel and structures, errors occur due to signal reflection and multi-path, etc., which makes it difficult to get the accurate location. To address this problem the following was done: first, a circular polarization patch antenna appropriate to the work site was used to reduce the degree of error that may occur from the antenna emission pattern and the particular Line of Sight (LOS); second, a 3-D localization technique and a filtering algorithm were used to improve the accuracy of location determination. The developed system was tested by using it on a wharf crane to validate its accuracy and effectiveness. The proposed location recognition system is expected to contribute greatly in ensuring the safety of workers at industrial work sites.

• The Journal of the Korea Contents Association
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• v.15 no.10
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• pp.587-596
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• 2015

3D scanners are applied to many industries, such as manufacturing, construction, and shipbuilding. Recently, 3D scanner is used in 3D imaging of worksite in order to control and guide earthmoving heavy equipments, which provides basic information for intelligent excavation. This study compares the accuracy and productivity between total stations and high-resolution 3D scanners. The analysis results show that 3D scanner has high accurate rate of greater than 99 percent and has low error rate of less than 2.0mm compared to total stations. In terms of productivity, 3D scanner saves 71 percent of measuring time compared to the total station. This study confirms that 3D scanner can measure the earthwork sites with high accuracy and better productivity.

• Journal of Cadastre & Land InformatiX
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• v.45 no.1
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• pp.1-15
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• 2015

Korea's Spatial Information Policy has been institutionalized based by "National Spatial Data Infrastructure Act", "Act on Land Survey, Waterway Survey and Cadastral Records", "Spatial Data Industry Promotion Act". In year 2015, These acts were modified with new names and contents. It is critical that the definition of spatial information ought to be generalized. In addition, it is of paramount importance to review factors those contribute to the systematic development on coherent relation between Spatial Information Act and other acts. Examples of improvement area may include: Categorization of Spatial Information Concept, Systematization of Spatial Data Related Legislation, and Enhancement of Organization Specializing in Spatial Information. Furthermore, Legislation & Policy case of Germany, France and the United States were used as a basis for improvement.

• Journal of the Korean Association of Geographic Information Studies
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• v.25 no.4
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• pp.200-209
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• 2022

Providing real-time location information is emerging as a major goal of the national industry. In order to provide such real-time location information (3D spatial information), it is essential to develop a technology for a satellite positioning method. Therefore, the country continues to make efforts to increase satisfaction with the needs of consumers by introducing the Network RTK GNSS method. In this study, among the Network RKT GNSS(Global Navigation Satellite System) methods provided by the National Geographic Information Service, continuous observation and single observation were measured at the integrated reference point using VRS(Virtual Reference Station) and FKP(Flӓachen-Korrektur Parameter) to evaluate accuracy. In addition, we aim to maximize efficiency by presenting accuracy on the rapidly increasing Network RTK GNSS method in the field.

• Proceedings of the Korea Water Resources Association Conference
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• 2022.05a
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• pp.6-6
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• 2022

최근 수재해에 대응하기 위한 물관리 환경은 기후변화에 따른 홍수 피해 심화와 댐과 하천 시설의 노후화 점증, 하천관리일원화 등 정책적 변화, 그리고 포스트코로나 디지털 혁신 등 복합적 대전환 시대 진입에 따라 복잡다단한 양상을 보이고 있다. 디지털 트윈은 디지털 대전환(digital transformation) 시대 다양한 산업 영역에서 지능화와 생산성 향상을 목적으로 도입되고 있다. 본 국가 시범사업에서는 170 km에 달하는 섬진강 유역 전체를 대상으로 홍수에 대응하기 위한 디지털 트윈 플랫폼(K-Twin SJ)을 구축하고 있다. 본 플랫폼은 국가 인프라 지능정보화 사업의 일환으로 시작되었으며, 공간정보와 시설물 모델링, 홍수 분석 등 수재해에 대응하기 위한 수자원 분야의 다학제적인 강소기업들과 K-water에서 컨소시엄을 구성하여 추진하고 있다. 본 사업의 내용은 섬진강 댐-하천 유역에 대하여 고정밀도 3D 공간정보화, 실시간 물관리 데이터 연계, 홍수 분석 시뮬레이션, AI 댐 운영 최적화, AI 사면 정보 생성, 하천 제방 안전성 평가, AI 지능형 CCTV 영상분석, 간이 침수피해 예측, 드론 제약사항 조사 체계 개발을 포함하고 있다. 물관리 데이터와 하천 시설정보를 트윈 플랫폼 상에서 위치기반으로 시각화 표출하기 위해서는 유역의 공간정보를 3차원으로 구축하는 과정이 필수적이다. 따라서 GIS 기반의 섬진강 하천 중심 공간정보 구축을 위해 유역의 국가 정사영상과 5m 수치표고모형(DEM)은 최신성과를 협조 받아 적용하였으며, 홍수 분석을 위한 하천 중심 공간정보는 신규 헬기에 LiDAR 매핑을 수행하여 0.5m 급 DEM을 신규 구축하였다. 또한 하천 시설물 중 섬진강댐과 79개 주요 하천 횡단 교량과 3개 보 시설을 지상기준점 측량과 드론 매핑, 패턴 방식의 경량화 작업을 통해 트윈에 탑재할 수 있는 시설물 3D 객체 모델을 제작하였다. 홍수 분석을 위해서는 섬진강 유역에 대해 K-Drum, K-River, K-Flood 모델을 구축하였으며, AI 하천 수위 예측 학습 모델을 개발하였다. 섬진강 디지털 트윈 유역 물관리 플랫폼을 통해 데이터 기반의 똑똑한 물관리를 구현하고자 한다.