• Korean Journal of Remote Sensing
• /
• v.39 no.6_3
• /
• pp.1679-1692
• /
• 2023

South Korea is a country that emits a large amount of pollutants as a result of population growth and industrial development and is also severely affected by transboundary air pollution due to its geographical location. As pollutants from both domestic and foreign sources contribute to air pollution in Korea, the location of air pollutant emission sources is crucial for understanding the movement and distribution of pollutants in the atmosphere and establishing national-level air pollution management and response strategies. Based on this background, this study aims to effectively acquire spatial information on domestic and international air pollutant emission sources, which is essential for analyzing air pollution status, by utilizing high-resolution optical satellite images and deep learning-based image segmentation models. In particular, industrial parks and quarries, which have been evaluated as contributing significantly to transboundary air pollution, were selected as the main research subjects, and images of these areas from multi-purpose satellites 3 and 3A were collected, preprocessed, and converted into input and label data for model training. As a result of training the U-Net model using this data, the overall accuracy of 0.8484 and mean Intersection over Union (mIoU) of 0.6490 were achieved, and the predicted maps showed significant results in extracting object boundaries more accurately than the label data created by course annotations.

• Journal of Climate Change Research
• /
• v.2 no.4
• /
• pp.253-267
• /
• 2011

This study summarizes some important results from the studies on clouds and aerosols, and their effects on climate in the northeast Asia that were made mainly by Korean scientists and some other scientists from around the world. Clouds and aerosols are recognized as one of the most important factors that contributes to uncertainties in climate predictions and therefore become the subject of active research in the western developed countries in recent years. However, the researches on clouds and aerosols are very weakly done in Korea except ground based measurements of aerosol physical, chemical and optical properties. These measurements indicate that aerosol loadings in the northeast Asia are generally much higher than other parts of the world. On the other hand, researches on clouds are few in Korea. Satellite and ground remote sensing, numerical modeling and aircraft in-situ measurements of clouds are highly needed for better assessment of the role of clouds on climate in the northeast Asia.

• The Bulletin of The Korean Astronomical Society
• /
• v.36 no.1
• /
• pp.73.1-73.1
• /
• 2011

세계전파통신회의 (WRC; World Radiocommunication Conference)회의는 국제전기통신연합(ITU)에서 발행하는 국제 전파법과 관련된 전파규약을 갱신하거나 새로운 법 제정을 위해, 3-4년 간격으로 개최되는 전파통신 관련 회의라고 할 수 있다. 차기 WRC회의는 2012년 1월23일 - 2월 17일에 개최되며, 따라서 동 회의에서 다룰 의제들의 사전 연구결과에 대한 보고서가 필요하다고 하겠다. 그러므로 WRC 본회의 개최 6개월 전에 상기 기술문서를 의제별로 종합 작성하기 위해 CPM (Conference Preperatory Meeting) 회의를 개최해야 하며, 본 CPM회의에서 작성된 기술보고서의 내용들은 WRC 본회의에서의 여러 가지 국제법의 결정사안에 대한 중요한 정보를 제공하게 된다고 할 수 있다. 2011년 2월 14일-2월 25일에 걸쳐 스위스에서 개최된 CPM-11 2차회의에서는 전파천문업무 보호 및 22 GHz 대역 달탐사, 38 GHz 대역 Space-VLBI운용대역과 관련된 WRC-11 의제 1.6, 1.11, 1.12 등에 대해 활발한 토론이 있었다. 따라서 국내의 달탐사계획과 관련되어, 신규주파수 분배를 다룬 WRC-12의제에 대해 동 회의의 최종결과 및 향후 WRC-12회의에 대한 대응책에 대해서도 알아보고자 한다.

• Transactions of the Korean Society of Mechanical Engineers B
• /
• v.32 no.11
• /
• pp.863-869
• /
• 2008

This paper investigated the new calibration algorithm of a straight-type five-hole pressure probe for measuring three-dimensional flow velocity components. This new calibration algorithm was used for velocity data reduction from the calibration map and based on the combination of a look-up, a binary search algorithm and a geometry transformation including the translation and reflection of nodes in a calibration map. The calibration map was expanded up to the application angle, ${\pm}55^{\circ}$ of a probe. This velocity data reduction method showed a perfect performance without any kind of interpolating errors in calculating yaw and pitch angles from the calibration map. Moreover, when it was applied to an actual flow field including a swirling flow, a good result came out on the whole.

• KSCE Journal of Civil and Environmental Engineering Research
• /
• v.40 no.3
• /
• pp.337-343
• /
• 2020

The third phase of NASA's 3D-Printed Habitat Challenge (part of a NASA's Centennial Challenges Program competition) required entrants to build a one-third-scale space exploration habitat (10 ㎡) using 3D-printing technology. This study addresses a proposed habitat (diameter: 3 m, height: 2 m) in accordance with the competition rules. The study focus is to find the most appropriate binder when KOHLS-1 was mixed for extruding and stacking as 3D printing feedstock using pellets, and to build a prototype structure as required by the competition. Unlike previous studies, this study was based around the binders and construction method, not around axis transfer velocity, flow rate, and heater temperature.

• Korean Journal of Remote Sensing
• /
• v.31 no.2
• /
• pp.193-203
• /
• 2015

In this study, effects of buildings and topography on observation environment of weather stations located on mountainous terrain in metropolitan areas are investigated using a computational fluid dynamics (CFD) model. In order to investigate the characteristics of flow pattern around the weather stations, geographic information system (GIS) data are used to construct surface boundary input data of the CFD model. In order to evaluate effects of buildings and topography on wind speed and direction at three weather stations located in Deajeon, Busan, and Gwangju., target areas around the weather stations are selected and 16 cases with different inflow directions for each target area are considered. The simulated wind speed and direction at the weather stations are compared with those of inflow. As a whole, wind speed at the weather stations decreases due to drag effects of the buildings and topography in the upwind regions. This study shows that GIS data and the CFD model are successfully applicable to evaluation of observation environment for weather stations.

• Korean Journal of Remote Sensing
• /
• v.36 no.6_2
• /
• pp.1567-1577
• /
• 2020

Urban land cover classification is role in urban planning and management. So, it's important to improve classification accuracy on urban location. In this paper, machine learning model, Support Vector Machine (SVM) and Artificial Neural Network (ANN) are proposed for urban land cover classification based on high resolution satellite imagery (KOMPSAT-3A). Satellite image was trained based on 25 m rectangle grid to create training data, and training models used for classifying test area. During the validation process, we presented confusion matrix for each result with 250 Ground Truth Points (GTP). Of the four SVM kernels and the two activation functions ANN, the SVM Polynomial kernel model had the highest accuracy of 86%. In the process of comparing the SVM and ANN using GTP, the SVM model was more effective than the ANN model for KOMPSAT-3A classification. Among the four classes (building, road, vegetation, and bare-soil), building class showed the lowest classification accuracy due to the shadow caused by the high rise building.

• Journal of the Korea Institute of Building Construction
• /
• v.1 no.2
• /
• pp.191-195
• /
• 2001

When top down method is used, it could be a construction method trouble in column joint, between the former concrete and the latter. It could bring a void and weak concrete in column. The purpose of this study is finding a way to prevent concrete void and concrete suitable for top down , through V-metering for top down column and concrete experiment. To minimize the void of reverse placement joint, It is more effect to use the sheath method then direct method in concrete placement.

• Journal of Environmental Impact Assessment
• /
• v.13 no.5
• /
• pp.223-230
• /
• 2004

The electrical resistivity prospecting method with dipole-dipole array were applied in order to survey 3-D structure characteristics of the Noen landfill site. For the electrical resistivity prospecting, 3 line of measurements were established parallel to the main boundary of the Noen landfill site and additional 2 lines were also established perpendicular to the existing 3 lines for the effective investigation of the landfill site. The results showed that the uppermost layer of the landfill site is believed to be stabilized generally based on the characteristics of electrical resistivity distribution. Lowest layer was partially polluted by the leachate.

• Proceedings of the Korean Society for Rock Mechanics Conference
• /
• 2003.03a
• /
• pp.121-134
• /
• 2003

본 연구대상은 $\bigcirc$$\bigcirc$우회도로 Sta.3＋300~600 구간에 형성된 높이 약 50m의 대절토 암반사면으로 대부분 절취가 완료된 상태에서, 1차로 사면 좌측부의 발파암과 풍화암의 경계부를 따라 인장균열이 소규모로 형성되면서 Slip 등 사면파괴활동이 시작되었으며, 2차로 활동높이 35m, 활동폭 40m, 활동깊이 약 l0m 규모로 붕괴되었고, 주변에도 인장균열의 발생이 확인되는 등 추가 붕괴의 징후가 있어 사면의 안정성을 검토하였다. Rock Cleavages가 발달한 천매암으로 구성된 파괴활동사면을 대상으로 지표지질조사, 추가시추조사, 전기비저항탐사, 시추공 영상촬영(BIPS)을 실시하여 사면붕괴의 원인과 추후에 예상되는 붕괴의 양상을 파악하고, 연구지역에 가장 적합한 보강대책을 수립하고자 하였다.