• Korean Journal of Agricultural and Forest Meteorology
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• v.16 no.4
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• pp.297-303
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• 2014

The effect of solar irradiance has been used to estimate daily maximum temperature, which make it possible to reduce the error inherent to lapse-rate based elevation difference correction in mountainous terrain. Still, recent observations indicated that the effect of solar radiation would need correction for estimation of daily maximum temperature. It was attempted to examine what would cause the variability of solar irradiance effect in determination of daily maximum temperature under natural field conditions and to suggest improved methods for estimation of the temperature distribution over mountainous regions. Temperature at 1500 and the wind speed for 1100 to 1500 were obtained at 10 validation sites with various topographical features including slope and aspect within a mountainous $50km^2$ catchment for 2012-2013. Lapse-rate corrected temperature estimates on clear days were compared with these observations, which would represent the differential irradiance effect among sloped surfaces. Results indicated a negative correlation between the mean wind speed and the estimation error. A simple scheme was derived from relationship between wind speed and estimation error for daily temperature to correct the effect of solar radiation. This scheme was incorporated into an existing model to estimate daily maximum temperature based on the effect of solar radiation. At 10 validation sites on clear days, estimates of 1500 LST temperature with and without the correction scheme were compared. It was found that a substantial improvement was achieved when the correction scheme was applied in terms of bias correction as well as error size reduction at all sites.

• Computational Structural Engineering
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• v.3 no.2
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• pp.109-115
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• 1990

The probabilistic characteristics of wind loads have been analyzed using statistical data on wind speeds, pressure coefficient, exposure coefficient, and gust factor. The wind speed data collected at 25 nationwide weather stations have been modified to be consistent in measuring height, exposure condition as well as averaging time. Having performed Monte Carlo simulation for various heights and site conditions, the statistical models of wind loads were determined, in which Type-I extreme value distribution has been applied. The models also incorporate a reduction factor of 0.85 to account for the reduced probability that the maximum wind speed will occur in a direction most unfavorable to the response of structure.

• Proceedings of the Korea Water Resources Association Conference
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• 2012.05a
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• pp.868-872
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• 2012

유역의 유입 및 유출은 강수에 의해 발생하며 여러 가지 기후 조건과 토지 상태의 영향을 받는다. SWAT(Soil and Water Assessment Tool) 모형은 이러한 여러 가지 복잡한 기후 조건과 토지 상태를 반영하며, 장기간 입력 자료에 따른 유출량을 산출할 수 있다. 본 연구에서는 시험유역을 안동댐 유역으로 선정하였으며, SWAT 모형을 이용하여 10년(2000년 ~ 2010년) 동안의 유출량을 산정하였고 이를 안동댐의 실측 유입량과 비교 분석하였다. ArcSWAT을 이용하여 분석하였고 입력 자료는 SWAT의 분석단위인 HRU(Hydrologic Response Unit)를 산정하기 위한 정밀 토양도 및 토지피복도와 기상입력 자료인 강우 및 최고기온, 최저기온, 습도, 풍속, 일사량 등을 사용하였다. 강우관측소는 안동댐 유역의 고선, 남회룡, 도천, 미질, 석동, 석포, 석현, 의촌, 재산, 황지를 선정하였고, 일사량관측소는 안동, 대관령, 포항을 선정하였으며, 기온, 습도, 풍속관측소는 안동, 봉화, 태백, 영주를 선정하였다. 또한 기상입력자료 중 결측값은 역거리 자승법을 이용하여 보완하였다. SWAT 모형은 유출량 계산 시 여러 가지 다양한 매개변수가 사용되며, 이러한 매개변수들의 검 보정을 통하여 실제 유역의 특성과 하천 흐름특성을 반영할 수 있다. 본 연구의 시험유역인 안동댐유역은 산림과 초지가 많은 지역이기 때문에 식물에 의해 차단되는 강우에 관한 매개변수와 지하로 침투되는 강우량에 관한 매개변수 등을 보정하여 실제 유역특성을 반영하였다. 본 연구에서는 이러한 과정을 통해 안동댐 유역의 10년 동안의 일 유출량을 산정한 결과, 홍수기의 첨두유량 및 첨두시간에는 실측자료와 약간의 차이가 있었지만 전체적으로 실측자료와 매우 유사한 유출량을 산정하였다.

• Journal of the Korea institute for structural maintenance and inspection
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• v.15 no.2
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• pp.153-160
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• 2011

Recently there are many long span cable supported bridges like Cable Stayed Bridge and Suspension Bridge already constructed or planned. Reconsidering of proper design wind load of long span bridge is required since the meteorological value based on the data only from 1960s to 1995 has been used when we estimate the wind load for designing long span bridges. In this paper, the research area was confined to western and southern coasts where many long span bridges have constructed. The method of moment and the least-squares method were used to estimate the expected wind speeds of 100 year's return period for girder bridges and for 200 year's return period for long span bridges based on the Gumbel's distribution. As the return-period wind speed on the land face was revised because of recent high speed velocity, the revised return-period wind speed is increased by 17%. Compatibility of return-period wind speed was also evaluated using RMS (Root Mean Square) error method. Aa a result of this paper, the least-squares method is more compatible than the method of moment in the case of western and southern coasts in Korea.

• 한국신재생에너지학회:학술대회논문집
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• 2011.05a
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• pp.63.1-63.1
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• 2011

본 연구에서는 제주 삼달 지역의 Hub 높이에서 측정된 실측 자료와 기상청에서 측정된 AWS 자료 1년(2010년)치를 토대로 Wind-Pro에 적용하여 풍황자원 분석을 하였다. 허브의 실측높이인 삼달지역 관측자료(100m)와 허브 보정값인 기상청 AWS 자료(15m)를 통해 각각의 연간발전량과 단지 효율을 측정하여 비교 분석하였고 실측높이와 보정치를 이용한 값을 적용하여 발전량 및 효율을 산출 비교하고 이를 통해 그 차이점을 분석하고자 한다. 이는 단지분석 시에 발생될 보정값의 불확도를 판단하는데 그 의의가 있다.

• Proceedings of the Korea Contents Association Conference
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• 2017.05a
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• pp.379-380
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• 2017

가상현실 기술의 발전과 환경 정보 수집을 위한 센서 기술의 발전에 따라 실감형 시뮬레이터에 실제 환경과 동일한 실감효과를 재현하기 위한 연구들이 많이 진행되고 있다. 컴퓨터를 이용한 가상환경에서 실감형 시뮬레이션을 위한 MPEG-V 표준에서는 바람, 진동, 속도, 풍향, 풍속, 온도, 안개 등의 효과들을 제공하기 위한 명세를 제공하고 있다. 본 연구에서는 사용된 이동형 환경데이터 수집 장치를 통해 수집된 데이터는 실감 재현 장치에 적용하기 위해서는 재현 장치의 구동 지연 및 성능에 따른 데이터의 보정이 필요하게 된다. 본 연구에서는 이동형 환경데이터 수집 장치를 통해 수집된 환경 데이터의 패턴 분석을 통해 실감 재현 장치에 적합한 실감 환경 데이터를 제공하기 위한 손실 데이터의 보정방법을 제안하고자 한다.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.30 no.6B
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• pp.617-625
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• 2010

The selection of a site where strong wind blows is important to increase effectively the electricity of wind power in proportion to the cube of the wind speed. It is advisable to establish the wind turbine in the coastal area with strong wind speed rather than in the inland. And the development of offshore wind energy is expected to solve the noise problem that is one of the important weaknesses in the wind turbine. In the process of the development business of wind energy, knowing forehead the wind power possibility in any area is one of the essential factors to choose the most optimum site of wind power. In this paper, the potential of wind power around JeJu coastal area is examined by using the wind data that Korea Meteorological Administration has surveyed for 10 years in 14 observation points. Wind speed data is revised to wind speed in 80 meters assuming installation height of the wind turbine, and wind power density and annual wind energy are also calculated. And annual electricity generation and percent of energy efficiency in all the observation points are estimated by using the information about 3,000 KW wind turbine.

• Proceedings of the KIEE Conference
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• 2009.07a
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• pp.553_554
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• 2009

풍력발전은 현재까지 가장 경제성이 있는 신재생에너지 기술이지만, 전적으로 바람에 의존함으로서, 발전전력의 양과 시스템의 효용성이 절대적으로 풍력자원의 특성에 지배된다. 본 논문은 제주한경풍력단지의 풍력발전량을 추정하기위하여, 인근에 위치한 고산기상대의 풍속측정 자료와 한경풍력의 풍력발전량을 분석하였다. 분석된 결과를 이용하여 예측된 풍속의 높이를 보정하여 미래 풍력발전량을 추정하였다.

• 한국신재생에너지학회:학술대회논문집
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• 2008.10a
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• pp.268-273
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• 2008

A linear wind prediction program, WAsP, was employed to predict wind speed at two different sites located in complex terrain in South Korea. The reference data obtained at locations more than 7 kilometers away from the prediction sites were used for prediction. The predictions from the linear model were compared with the measured data at the two prediction sites. Two compensation methods such as a self-prediction error method and a delta ruggedness index (RIX) method were used to improve the wind speed prediction from WAsP and showed a good possibility. The wind speed prediction errors reached within 3.5 % with the self prediction error method, and within 10% with the delta RIX method. The self prediction error method can be used as a compensation method to reduce the wind speed prediction error in WAsP.

• Journal of Korea Water Resources Association
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• v.36 no.2
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• pp.237-249
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• 2003

Wind effects on a rain gauge can cause a significant underestimation of rainfall depths and contribute to the inconsistency in rainfall data. To revise the rainfall data requires the study about calculation of deficiency percentages of rain catch. There are few studies which reflect the variation of wind speed. in this study, the raindrop terminal velocity is quantified according to the particle size of rainfall. The model for calculating deficiency percentages of rain catch according to the particle size of rainfall is examined by experimentation. Experimentation shows that deficiency percentages of rain catch have no relationship with rainfall intensity and affected by raindrop diameter. In conclusion, the estimated deficiency percentages of rain catch coincided with the experimental results and can be used as recommended adjustment factors.