• 한국대기환경학회지
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• 제18권2호
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• pp.67-83
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• 2002

The coupled model (SMART) of dynamic meteorology model and particle dispersion model was developed. The numerical experiment on the relationship between change of land use and diffusion behavior in complex terrain was carried out using this model. It tried to investigate the change of particle diffusion behavior and local weather under the condition in which land-land breeze and sea breeze and mountain breeze intermingled. The numerical experiment results are as follows; 1) The more complicated local circulation field of the interaction of sea breeze, mountain breeze and Land -land breeze is formed. Then, the region circulation in which the urbanization is specific by location of the region is strengthened and is weakened. 2) Though in the region with dominant sea breeze, Land-land breeze does not appear directly, the progress of the sea wind to the inland is affected. 3) In the prediction of the air diffusion, emission high quality and accurate information of the emission site are important. That is to say, the dispersion predicting result which emission high quality and small error of the site perfectly vary for Land - land breeze in the effect may be brought about.

• Wind and Structures
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• 제20권1호
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• pp.59-74
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• 2015

A coupled model system for Wind Resource Assessment (WRA) was studied. Using a mesoscale meteorological model, the Weather Research and Forecasting (WRF) model, global-scale data were downscaled to the inner nested grid scale (typically a few kilometers), and then through the coupling Computational Fluid Dynamics (CFD) mode, FLUENT. High-resolution results (50 m in the horizontal direction; 10 m in the vertical direction below 150 m) of the wind speed distribution data and ultimately refined wind farm information, were obtained. The refined WRF/FLUENT system was then applied to assess the wind resource over complex terrain in the northern Poyang Lake region. The results showed that the approach is viable for the assessment of wind energy.

• 한국태양에너지학회 논문집
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• 제33권6호
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• pp.1-11
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• 2013

The investigation on wind farm design using CFD technique was carried out to reduce turbulence intensity in a wind farm. A potential wind farm in Gasiri of Jeju Island was selected for the design and the commercial S/W of Meteodyn WT was used for applying CFD technique. The initial layout of wind turbines was derived using WindPRO which is mainly used for wind farm design in Korea. Then, the distribution of turbulence intensity on complex terrain was calculated and visible by Meteodyn WT. Based on the distribution, wind turbines were positioned properly. As a result, wind turbines could be deployed at positions with minimum turbulence intensity as well as maximum Annual Energy Production, AEP, using Meteodyn WT. It is necessary to take into account turbulence intensity in wind farm design to avoid wind turbine failure.

• 한국환경과학회지
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• 제16권8호
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• pp.921-928
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• 2007

The objective of this work is the air quality modeling according to the scenarios of emission on complex terrain. The prognostic meteorological fields and air quality field over complex areas of Seoul, Korea are generated by the PSU/NCAR mesoscale model (MM5) and the Third Generation Community Multi-scale Air Quality Modeling System (Models - 3/CMAQ), respectively. The emission source was driven from the Clean Air Policy Support System of the Korea National institute of Environmental Research (CAPSS), which is a 1 km x 1 km grid in South Korea during 2003. In comparison of air quality fields, the simulated averaged $PM_{10},\;NO_2,\;and\;O_3$ concentration on complex terrain in control case were decreased as compared with base case. Particularly $PM_{10}$ revealed most substantial localized differences by $(18{\sim}24{\mu}g/m^3)$. The reduction rate of $PM_{10},\;NO_2,\;and\;O_3$ is respectively 18.88, 13.34 and 4.17%.

• 한국환경과학회지
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• 제19권1호
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• pp.27-37
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• 2010

A system coupled the prognostic WRF mesoscale model and CALMET diagnostic model has been employed for predicting high-resolution wind field over complex coastal area. WRF has three nested grids down to from during two days from 24 August 2007 to 26 August 2007. CALMET simulation is performed using both initial meteorological field from WRF coarsest results and surface boundary condition that is Shuttle Radar Topography Mission (SRTM) 90m topography and Environmental Geographic Information System (EGIS) 30m landuse during same periods above. Four Automatic Weather System (AWS) and a Sonic Detection And Ranging (SODAR) are used to verify modeled wind fields. Horizontal wind fields in CM_100m is not only more complex but better simulated than WRF_1km results at Backwoon and Geumho in which there are shown stagnation, blocking effects and orographically driven winds. Being increased in horizontal grid spacing, CM_100m is well matched with vertically wind profile compared SODAR. This also mentions the importance of high-resolution surface boundary conditions when horizontal grid spacing is increased to produce detailed wind fields over complex terrain features.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2001년도 제14회 신호처리 합동 학술대회 논문집
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• pp.117-120
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• 2001

Synthetic aperture radar (SAR) is a promising active remote sensing technique to obtain large terrain information of the earth in all-weather conditions. SAR is useful in many applications, including terrain mapping and geographic information system (GIS), which use SAR display images. Usually, these applications need the enormous data storage because they deal with wide terrain images with high resolution. So, compression technique is a useful approach to deal with SAR display images with limited storage. Because there is some indispensable data loss through the conversion of a complex SAR image to a display image, some applications, which need high-resolution images, cannot tolerate more data loss during compression. Therefore, lossless compression is appropriate to these applications. In this paper, we propose a novel lossless compression technique for a SAR display image using one-step predictor and block arithmetic coding.

• 한국측량학회:학술대회논문집
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• 한국측량학회 2004년도 추계학술발표회 논문집
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• pp.275-279
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• 2004

This study was done to detect the topographic and terrain change of the vicinity of the west coast. To make the basic map of the change in topology and terrain, the mosaic images were made using the images from the satellite, which were given the geometric correction based on the GCP (Ground Control Point) and DEM (Digital Elenation Model) data. The accuracy of the images was examined by .empaling them with CCP through 1:25,000's digital map. After that, among the resultant images of the 1970s and 2000s, those of Sihwa, Hwaong and Ansan, the lands reclaimed by drainage were compared to observe the change in the area. From this study, the accuracy of the images of the west coast from satellite could be acquired and the change of the topology and terrain was detected effectively. From the results, it was known that, in case of the land the topological change was not so big due to the development in the reclaimed land or the bare land. In Sihwa, the size of the land was increased 180 $\textrm{km}^2$ and that of the seashore was decreased 110 km. in Hwaong the size was increased 50 $\textrm{km}^2$ and in Ansan the city space was increased 71 $\textrm{km}^2$ due to the formation of the industrial complex.

• 한국항공운항학회지
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• 제31권3호
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• pp.50-58
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• 2023

Sudden wind changes at low altitudes pose a significant threat to aircraft operations. In particular, airports located in regions with complex terrain are susceptible to frequent abrupt wind variations, affecting aircraft takeoff and landing. To mitigate these risks, Low Level Wind shear Alert System (LLWAS) have been implemented at airports. This study focuses on understanding the characteristics of wind shear and developing a prediction model for Jeju International Airport, which experiences frequent wind shear due to the influence of Halla Mountain and its surrounding terrain. Using two years of LLWAS data, the study examines the occurrence patterns of wind shear at Jeju International Airport. Additionally, high-resolution numerical model is utilized to produce forecasted information on wind shear. Furthermore, a comparison is made between the predicted wind shear and LLWAS observation data to assess the prediction performance. The results demonstrate that the prediction model shows high accuracy in predicting wind shear caused by southerly winds.

• 한국농림기상학회지
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• 제15권1호
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• pp.17-25
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• 2013

본 연구는 복잡한 산악지형에서 바람장 변화를 해석하고, 산불발생시 확산방향을 예측하여 산불방지 전략에 활용하기 위해서 수행되었다. 연구 대상지는 2000년 4월 7일 산불이 발생하여 10일간 진행되었던 삼척지역을 대상으로 하였다. 삼척 산불피해지는 복잡한 산악구조를 가지고 있는데 먼저 중규모 기상 모델인 WRF를 사용하여 대상지에 설치한 AWS(4 지점)의 관측결과와 비교하였다. WRF 모의 결과, 4개 지점의 풍속은 AWS 관측지점의 풍속에 비해 5~8m/s(200% 과대평가) 강하였으며, 관측된 풍향은 지점마다 다양하게 나타난 것에 비해 모의된 풍향은 모든 지점에서 서풍계열로 나타났다. 결과적으로 WRF와 같은 중규모 기상모델은 복잡한 산악지형에서의 바람장 변화를 잘 모의하지 못하였다. 이러한 문제점을 해결하기 위해 미기상 대기유동장 수치모형인 ENVI-met 프로그램을 이용하여 지표면 높이에서 삼척 LTER 지역의 국지규모 바람장을 모의하였다. 지형효과에 의한 모델의 민감도를 위해 다양한 초기 조건(기류, 온 습도, 대기난류, 토양 및 식생 모형)들을 고려하여 분석하였다. ENVI-met 모의결과, 풍속은 실측과 비교할 때 약 70%의 정확도를 보였으며, 풍향은 계곡부와 능선부에서 지형효과로 인한 변화를 잘 반영하였다. 향후 ENVI-met은 산불확산예측 및 산불방지전략 수립을 위해 미기상 대기유동장 수치모형을 이용하여 산악지역의 미기상 해석에 관한 연구가 필요할 것으로 판단된다.

• 한국농림기상학회지
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• 제21권4호
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• pp.221-228
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• 2019

일출 이후부터 일몰 전까지 매시 간격으로 태양 일사로 인한 지표부근 기온상승 효과와 풍속이 미치는 영향을 추정하고자, 동향사면과 서향사면 간 대표 기상관측지점에 대하여 매시 일사량 편차에 따른 관측기온의 편차(기온변화량)을 풍속별로 구분하여 도출하였다. 일사편차 1 MJ/㎡ 당 기온변화량으로 일사효과를 표현하여 풍속과의 경험식을 구하고, 이것을 토대로 2018년 1월부터 2018년 12월까지 농산촌의 복잡지형에 위치한 기상관측지점 25곳에 대해 주간(06:00~19:00) 매시 기온을 추정한 후 검증하였다. 그 결과 추정값과 관측값의 평균 ME는 -0.98~0.67℃, 평균 RMSE는 0.95~2.04℃ 나타났다. 오후 3시 기준의 한낮기온은 선행연구에서 제시한 기존 모형과 추정신뢰도를 대조하였는데, 기존 모형의 추정오차(ME -0.91℃, RMSE 1.47℃)를 ME -0.45℃, RMSE 1.22℃까지 개선시킬 수 있었다.