• 한국해양공학회:학술대회논문집
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• 한국해양공학회 2004년도 학술대회지
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• pp.111-116
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• 2004

We surveyed the coastal structure damages due to the typhoon 'Mae-mi' which heavily struck Korean peninsula in September 12, 2003. The survey revealed the typhoon induced high tides and strong winds were the main causes especially in Busan areas. Though some experimental real time coastal monitoring stations captured the typhoon movements at the critical time, more systematic and complete systems should be implemented to save human lives and properties from huge typhoon disasters.

• 한국해양공학회지
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• 제18권2호
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• pp.25-32
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• 2004

We surveyed the coastal structure damage created by typhoon ‘Maemi’, which heavily struck the Korean peninsula on September 12, 2003. The survey revealed that high tides and strong winds induced by the typhoon were the main causes of the coastal damage, especially in the Busan areas. Though some experimental real-time coastal monitoring stations captured the typhoon movements at the critical time, more systematic and complete system should be implemented to save human lives and property from huge typhoon disasters.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2006년도 제37회 하계학술대회 논문집 A
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• pp.165-166
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• 2006

Recently, after Wide Area Outage of the North-Eastern United States occurred, many countries started to be concerned about WAMS (Wide Area Monitoring System), and Korean power system also experienced Wide Area outage according to typhoon Mae-Mi, and Haenam-Jeju HVDC line fault. Since it is too difficult to detect a symptom based on SCADA or EMS, a defense system of electric power infrastructure has required. In this research, the designed and developed system processes the time synchronized real time power system information based on GPS and shows the 2D/3D monitoring viewer using the phasor data and the results of three algorithms.

• 한국물환경학회지
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• 제24권2호
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• pp.185-194
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• 2008

There is increased soil erosion potential at highland agricultural crop fields because of its topographic characteristics and site-specific agricultural management practices performed at these areas. The agricultural upland fields are usually located at the sloping areas, resulting in higher soil loss, pesticides, and nutrients in case of torrential rainfall events or typhoon, such as 2002 Rusa and 2003 MaeMi. At the highland agricultural fields, the soil reconditioning have been performed every year to decrease damage by continuous cropping and pests. Also it has been done to increase crop productivity and soil fertility. The increased amounts of soil used for soil reconditioning are increasing over the years, causing significant impacts on water quality at the receiving water bodies. In this study, the field investigation was done to check soil reconditioning status for potato, carrot, and cabbage at the Doam-dam watershed. With these data obtained from the field investigation, the Soil and Water Assesment Tool (SWAT) model was used to simulate the soil loss reduction with environment-friendly and agronomically enough soil reconditioning. The average soil reconditioning depth for potato was 34.3 cm, 48.3 cm for carrot, and 31.2 cm for cabbage at the Doam-dam watershed. These data were used for SWAT model runs. Before the SWAT simulation, the SWAT ArcView GIS Patch, developed by the Kangwon National University, was applied because of proper simulation of soil erosion and sediment yield at the sloping watershed, such as the Doam-dam watershed. With this patch applied, the Coefficient of Determination ($R^2$) value was 0.85 and the Nash-Sutcliffe Model Efficiency (EI) was 0.75 for flow calibration. The $R^2$ value was 0.87 and the EI was 0.85 for flow validation. For sediment simulation, the $R^2$ value was 0.91 and the EI was 0.70, indicating the SWAT model predicts the soil erosion processes and sediment yield at the Doam-dam watershed. With the calibrated and validated SWAT for the Doam-dam watershed, the soil erosion reduction was investigated for potato, carrot, and cabbage. For potato, around 19.3 cm of soil were over applied to the agricultural field, causing 146% of more soil erosion rate, approximately 33.3 cm, causing 146% of more soil erosion for carrot, and approximately 16.2 cm, causing 44% of more soil erosion. The results obtained in this study showed that excessive soil reconditioning are performed at the highland agricultural fields, causing severe muddy water issues and water quality degradation at the Doam-water watershed. The results can be used to develop soil reconditioning standard policy for various crops at the highland agricultural fields, without causing problems agronomically and environmentally.

• 한국농공학회논문집
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• 제62권1호
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• pp.83-93
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• 2020

East Asia, which includes China, Japan, Korea, and Mongolia, is highly impacted by hydroclimate extremes such drought, flood, and typhoon recent year. In 2017, more than 18.5 million hectares of crops have been damaged in China, and Korea has suffered economic losses as a result of severe drought. Satellite-derived rainfall products are becoming more accurate as space and time resolution become increasingly higher, and provide an alternative means of estimating ground-based rainfall. In this study, we verified the availability of rainfall products by comparing widely used satellite images such as Climate Hazards Groups InfraRed Precipitation with Station (CHIRPS), Global Precipitation Climatology Centre (GPCC), and Precipitation Estimation From Remotely Sensed Information Using Artificial Neural Networks-Climate Data Record (PERSIANN-CDR) with ground stations in East Asia. Also, the satellite-based rainfall products were used to calculate the Standardized Precipitation Index (SPI). The temporal resolution is based on monthly images and compared with the past 30 years data from 1989 to 2018. The comparison between rainfall data based on each satellite image products and the data from weather station-based weather data was shown by the coefficient of determination and showed more than 0.9. Each satellite-based rainfall data was used for each grid and applied to East Asia and South Korea. As a result of SPI analysis, the RMSE values of CHIRPS were 0.57, 0.53 and 0.47, and the MAE values of 0.46, 0.43 and 0.37 were better than other satellite products. This satellite-derived rainfall estimates offers important advantages in terms of spatial coverage, timeliness and cost efficiency compared to analysis for drought assessment with ground stations.

• 대한원격탐사학회지
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• 제36권5_3호
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• pp.1037-1051
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• 2020

최근 기후변화로 인해 강도가 높은 태풍의 빈도가 높아짐에 따라 태풍 예측의 중요성이 강조되고 있는 데, 태풍경로예측에 비해 태풍강도예측에 대한 연구는 미비한 상황이다. 이에 본 연구에서는 딥러닝 모델인 Multi-task learning (MTL) 기법을 활용하여 정지궤도기상위성을 활용한 관측자료와 수치예보모델을 융합한 실시간 추정 및 6시간, 12시간 후의 태풍강도예측 모델을 제안하고자 한다. 본 연구에서는 2011년에서 2016년까지 북서태평양에서 발생한 총 142개의 태풍을 대상으로 강도 예측 연구를 시행하였다. 한국 최초의 기상위성인 Communication, Ocean and Meteorological Satellite (COMS) Meteorological Imager (MI)를 활용하여 태풍의 관측영상을 추출하였고, National Center of Environmental Prediction (NCEP)에서 제공하는 Climate Forecast System version 2 (CFSv2)를 활용하여 6시간, 12시간 후의 태풍 주변 대기 및 해양 예측변수를 추출하였다. 본 연구에서는 각 입력자료의 활용성을 정량화 하기 위하여, 위성 기반 태풍관측영상만을 활용한 MTL 모델(Scheme 1)과 수치예보모델을 융합적으로 활용한 MTL 모델(Scheme 2)을 구축하고, 각 모델의 훈련 및 검증 성능을 정량적으로 비교하였다. 실시간 강도 추정의 결과 scheme 1과 scheme 2에서 비슷한 성능을 보이는 반면, 6시간, 12시간 후 태풍강도예측의 경우 scheme 2에서 각각 13%, 16% 개선된 결과를 보였다. 태풍 단계별 예측성능에 대한 분석을 시행한 결과, 저강도 태풍일수록 낮은 평균제곱근오차를 보인 반면, 대부분의 강도 단계에서 평균제곱근편차비는 30% 미만의 값을 보이며 유의미한 검증 결과를 보였다. 이에 본 연구에서 제시한 두가지 모델을 기반으로 2014년 발생한 태풍 HALONG의 시계열검증을 시행하였다. 그 결과, scheme 1의 경우 태풍 초기발달단계에서 태풍의 강도를 약 20 kts가량 과대 추정하는 경향을 보이는데, 환경예측자료를 융합한 scheme 2에서는 오차가 약 5 kts가량으로 과대 추정 경향이 줄어들었다. 본 연구에서 제시하는 현재, 6시간, 12시간 후 강도를 동시에 추출하는 MTL 모델은 Single-tasking model 대비 약 300%의 시간 효율을 보이며, 향후 신속한 태풍 예보 정보 추출에 큰 기여를 할 수 있을 것으로 기대된다.