• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.3
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• pp.587-593
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• 2019

The field of geospatial information is rapidly changing due to the development of sensor and data processing technology that can acquire location information. And demand is increasing in various related industries and social activities. The construction and utilization of three dimensional geospatial information that is easy to understand and easy to understand can be an essential element to improve the quality and reliability of related services. In recent years, 3D laser scanners are widely used as 3D geospatial information construction technology. However, 3D laser scanners may cause shadow areas where data acquisition is not possible when objects are large in size or complex in shape. In this study, 3D model of an object has been created by acquiring oblique images using an unmanned aerial vehicle and processing the data. The study area was selected, oblique images were acquired using an unmanned aerial vehicle, and point cloud type 3D model with 0.02 m spacing was created through data processing. The accuracy of the 3D model was 0.19m and the average was 0.11m. In the future, if accuracy is evaluated according to shooting and data processing methods, and 3D model construction and accuracy evaluation and analysis according to camera types are performed, the accuracy of the 3D model will be improved. In the point cloud type 3D model, Cross section generation, drawing of objects, and so on, it is possible to improve work efficiency of spatial information service and related work.

• Korean Journal of Heritage: History & Science
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• v.38
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• pp.223-284
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• 2005

Gwaebul, created during late Joseon dynasty, especially from 1885 to 1926, now exist 18 ones. And 12 of them are owned by Buddhist temples located in Seoul city and Gyeonggido province. Royal Tomb praised and Royal household praised Buddhist temples in early Joseon dynasty were supported by Royal Family. As a renovation of Buddhist temples by king Taejong's reign(1400-1418), they became impoverished with reduced Buddhist ceremony. But they maintained their lives in intimate connection with royal family, and went prosperous from late 18th century. At that times, a new trend in Gwaebul appeared, which have popular idea for wishing peace of the dead, the nation and the royal family. The new composition of painting expressed in Gwaebul starts in Amitabha-Triad paintings which carved in first volume of ${\ll}$Amita-yohaegyeong${\gg}$ made of wooden plate. And Gi-heoh(A.D. 1820-1872) carved it in 1853 at Naewonam Buddhist hermitage of Samgaksan mountain And a return of Suwolgwaneumdo which had been popularized in late Goryo dynasty is worth noticing as a new issue of late Joseon dynasty. It is related with a composition of Gwaebul that expressed 'a leading the dead to the good', a Buddhist consciousness of falsehood and fancy. The saturated and blurred style of painting, the fact that centralization-powered lineage of painter who used composition of multi-used basic pattern, are characteristics of this period.

• Journal of the Society of Disaster Information
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• v.15 no.1
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• pp.39-48
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• 2019

Purpose: This study aims at developing and implementing Smart Safety Management System based on IoT/ICT Convergence for safety of high-risk groups working at disaster or industrial field. Its functions are as follows. Method: We will develop three devices for keeping the safety of high-risk jobs: Sensor of inactivity, Lora based Refitting technology for communication between high-risk workers, and Lora Gateway for monitoring entire situations. Then we will test three devices in respect of their functions, and propose their applicabilities in the field. Results: The system can send and receive safety tags and danger signals by which sensor technology can detect dangerous state of workers. And its command terminal was developed by low-power wireless communication technology and LoRa Gateway, which can fulfill the lifting functions between safety tags. And, furthermore, the command terminal can monitor dangerous situations of disaster sites in real time and can perform the preemptive rescues. Conclusion: This study proves the functional efficacy of Smart Safety Management System for worker safety in various high-risk occupational groups, and also suggests ways to secure worker safety in disaster area and various high risk industrial sites.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.22 no.1
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• pp.621-626
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• 2021

In this study, data on the study site for apartment construction was acquired, and the quantity of construction waste was calculated using a drone and mobile 3D laser scanner. The accuracy of the drone was 0.034 to 0.064m in the horizontal and vertical directions, respectively, and the mobile 3D Laser Scanner showed an accuracy of 0.018 to 0.049m in the horizontal direction, respectively. These results suggest that it is possible to construct spatial information using a drone and mobile 3D laser scanner with a value within the allowable accuracy of 1:1,000 digital terrain. The volume of construction waste calculated using the mobile 3D laser scanner data was 70,797㎥. It was possible to calculate the volume on the side of the building or some facilities that appeared as shaded areas in the drone outcomes. In addition, modeling was performed for view analysis of the apartments scheduled to be constructed and the terrain-based modeling results of the surrounding buildings. In the future, data construction and accuracy evaluation using mobile 3D laser scanners will be conducted. In addition, additional research comparing existing methods and work processes will be carried out, and the efficiency of mobile 3D laser scanners in the field of spatial information construction can be presented.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.20 no.6
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• pp.117-132
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• 2021

Due to the terrain in Korea, there are many road sections passing through mountainous areas. During the winter, there is a higher risk of traffic accidents, due to black ice caused by the lack of sunlight. Despite domestic road freezing safety measures, accidents caused by road freezing results in severe traffic accidents. Under these considerations, this study analyzed whether traffic safety signs that change in response to the external temperature help drivers recognize frozen road segments. The study was conducted through analysis of the effect of the signs on a driver's perspective. For the signs under development, out of the signs designed by experts, the sign design which received the highest visibility and effectiveness evaluation ratings from the general public was selected. The sign was implemented through Virtual Reality (VR) and installed on the right side of the road to analyze the effect on gazing and driving behavior. As a result of analyzing the driver's driving behavior, a speed reduction of about 7km/h or more was found in the sign section. Therefore, It was found that the existence of the sign had a strong relationship with the rate of the drivers' speed reduction.

• Journal of the Korean Geotechnical Society
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• v.38 no.12
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• pp.125-134
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• 2022

The Global Expansion Roadmap published by the International Space Exploration Coordination Group, which is organized by space agencies around the world, presents future lunar exploration guidance and stresses a lunar habitat program to utilize lunar resources. The Moon attracts attention as an outpost for deep space exploration. Simulating lunar surface environments is required to evaluate the performances of various equipment for future lunar surface missions. In this paper, an experimental study was conducted to simulate high vacuum pressure and cryogenic temperature of the permanent shadow regions in the lunar south pole, which is a promising candidate for landing and outpost construction. The establishment of an efficient dirty thermal vacuum chamber (DTVC) operation process has never been presented. One-dimensional ground cooling tests were conducted with various vacuum pressures with the Korean Lunar Simulant type-1 (KLS-1) in DTVC. The most advantageous vacuum pressure was found to be 30-80 mbar, considering the cooling efficiency and equipment stability. However, peripheral cooling is also required to simulate a cryogenic for not sublimating ice in a high vacuum pressure. In this study, an efficient peripheral cooling operation process was proposed by applying the frost ratio concept.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.22 no.6
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• pp.114-123
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• 2023

With the development of computer vision technology, video sensors such as CCTV are detecting incident. However, most of the current incident have been detected based on existing fixed imaging equipment. Accordingly, there has been a limit to the detection of incident in shaded areas where the image range of fixed equipment is not reached. With the recent development of edge-computing technology, real-time analysis of mobile image information has become possible. The purpose of this study is to evaluate the possibility of detecting expressway emergencies by introducing computer vision technology to dash cam. To this end, annotation data was constructed based on 4,388 dash cam still frame data collected by the Korea Expressway Corporation and analyzed using the YOLO algorithm. As a result of the analysis, the prediction accuracy of all objects was over 70%, and the precision of traffic accidents was about 85%. In addition, in the case of mAP(mean Average Precision), it was 0.769, and when looking at AP(Average Precision) for each object, traffic accidents were the highest at 0.904, and debris were the lowest at 0.629.

• Journal of Advanced Navigation Technology
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• v.28 no.1
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• pp.102-108
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• 2024

In the initial stages of urban air mobility (UAM) operations, compliance with existing visual flight rules and instrument flight regulations for conventional human-crewed aircraft is crucial. Additionally, voice communication between the on board pilot and relevant UAM stakeholders, including vertiports, is essential. Consequently, very high frequency (VHF) aviation voice communication must be consistently provided throughout all phases of UAM operations. This paper presents the results of the VHF communication coverage analysis for the initial UAM demonstration areas, encompassing the Hangang River and Incheon Ara-Canal corridors, as well as potential vertiport candidate locations. By considering the influence of terrain and buildings through the utilization of a digital surface model (DSM), communication quality prediction results are obtained for the analysis areas. The three-dimensional coverage analysis results indicate that stable coverage can be achieved within altitude corridors ranging from 300 m to 600 m. However, there are shaded areas in the low-altitude vertiport regions due to the impact of high-rise buildings. Therefore, additional research to ensure stable coverage around vertiports in the lower altitude areas is required.

• Korean Journal of Remote Sensing
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• v.34 no.3
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• pp.439-450
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• 2018

The lineament is a linear or curved terrain element to discriminate adjacent geological structures in each other. It has been widely used for analysis of geology, mineral exploration, natural disasters, and earthquake, etc. In the past, the lineament has been extracted using cartographic map or field survey. However, it is possible to extract more efficiently the lineament for a very wide area thanks to development of remote sensing technique. Remotely sensed observation by aircraft, satellite, or digital elevation model (DEM) has been used for visual recognition for manual lineament extraction. Automatic approaches using computer science have been proposed to extract lineament more objectively. In this study, we evaluate the characteristics of lineament which is automatically extracted with respect to difference of spatial resolution of DEM. We utilized two types of DEM: one is Shuttle Radar Topography Mission (SRTM) with spatial resolution of about 90 m (3 arc sec), and the other is the latest world DEM of TerraSAR-X add-on for Global DEM with 12 m spatial resolution. In addition, a global DEM was resampled to produce a DEM with a spatial resolution of 30 m (1 arc sec). The shaded relief map was constructed considering various sun elevation and solar azimuth angle. In order to extract lineament automatically, we used the LINE module in PCI Geomatica software. We found that predominant direction of the extracted lineament is about $N15-25^{\circ}E$ (NNE), regardless of spatial resolution of DEM. However, more fine and detailed lineament were extracted using higher spatial resolution of DEM. The result shows that the lineament density is proportional to the spatial resolution of DEM. Thus, the DEM with appropriate spatial resolution should be selected according to the purpose of the study.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.35 no.6
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• pp.553-562
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• 2017

GPS (Global Positioning System) receiver among various sensors mounted on UAV (Unmanned Aerial Vehicle) helps to perform various functions such as hovering flight and waypoint flight based on GPS signals. GPS receiver can be used in an environment where GPS signals are smoothly received. However, recently, the use of UAV has been diversifying into various fields such as facility monitoring, delivery service and leisure as UAV's application field has been expended. For this reason, GPS signals may be interrupted by UAV's flight in a shadow area where the GPS signal is limited. Multipath can also include various noises in the signal, while flying in dense areas such as high-rise buildings. In this study, we used analytical photogrammetry and auto tracking total station technique for 3D positioning of UAV. The analytical photogrammetry is based on the bundle adjustment using the collinearity equations, which is the geometric principle of the center projection. The auto tracking total station technique is based on the principle of tracking the 360 degree prism target in units of seconds or less. In both techniques, the target used for positioning the UAV is mounted on top of the UAV and there is a geometric separation in the x, y and z directions between the targets. Data were acquired at different speeds of 0.86m/s, 1.5m/s and 2.4m/s to verify the flight speed of the UAV. Accuracy was evaluated by geometric separation of the target. As a result, there was an error from 1mm to 12.9cm in the x and y directions of the UAV flight. In the z direction with relatively small movement, approximately 7cm error occurred regardless of the flight speed.