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        검색결과 49

        21.
        1993.12 구독 인증기관·개인회원 무료
        22.
        1992.12 구독 인증기관·개인회원 무료
        31.
        2016.02 KCI 등재 서비스 종료(열람 제한)
        To predict annual energy production (AEP) accurately in the wind farm where located in Seongsan, Jeju Island, Equivalent wind speed (EQ) which can consider vertical wind shear well than Hub height wind speed (HB) is calculated. AEP is produced by CFD model WindSim from National wind resource map. EQ shows a tendency to be underestimated about 2.7% (0.21 m/s) than HB. The difference becomes to be large at nighttime when wind shear is large. EQ can be also affected by atmospheric stability so that is classified by wind shear exponent (). AEP is increased by 11% when atmosphere becomes to be stabilized ( > 0.2) than it is convective ( < 0.1). However, it is found that extreme wind shear ( > 0.3) is hazardous for power generation. This results represent that AEP calculated by EQ can provide improved accuracy to short-term wind power forecast and wind resource assessment.
        32.
        2015.08 KCI 등재 서비스 종료(열람 제한)
        The Ministry of Trade, Industry and Energy is now placing emphasis on the importance of a new and renewable energy resource map service as an essential means of promoting the dissemination and adoption of renewable energy and other related industrial activities. To raise satisfaction with the new and renewable energy resource map service and promote its utilization, a survey was conducted on a sample group with an academic research background, i.e. employees of the Korea Institute of Energy Research (KIER) who have a thorough understanding of the technological concepts behind the new and renewable energy resource map. Statistical analysis of the survey results showed a high level of overall satisfaction with the web service for the new and renewable energy resource map. Therefore, it was concluded that the development of practical contents rather than the enhancement of web service convenience is required. A statistically significant trend was also observed whereby, the longer the professional career of the survey respondents, the greater their perception and utilization of, and satisfaction with, the enhanced service, which indicates that their level of understanding and utilization of technological concepts corresponds to their research experience record. In addition, the results obtained from the questionnaires regarding the evaluation of the utilization value of the resource map service indicated that use of the service was equally high in terms of political, business and academic applications. The results confirmed the need to develop multidimensional resource map contents that can be applied to as many fields as possible, rather than focusing on a specific terrain.
        33.
        2014.11 KCI 등재 서비스 종료(열람 제한)
        In order to decide the location of appropriate onshore wind farm with higher potential wind energy, several decision processes using Geographic Information System (GIS) including Digital Elevation Map (DEM) were proposed and we also estimated the wind resources through the proposed decision process. Decision process consists with three steps. First step is excluding inappropriate location geographically using DEM data including SRTM (Shuttle Radar Topography Mission) terrain data, landslide, land-use, roadway, and forest road data. And the second step of decision process is consideration of the difficulty caused by the natural environmental problem. This step is carried out using ECVAM (Environmental Conservation Value Assessment Map) data. And final step is determination of the most suitable location through the Moving Suitability Identification Method (MSIM) based on the moving potentially estimated wind resources area. Proposed decision process was applied over the Korean Peninsula. Wind resource potential estimated by the first and the second step is cases shows 35.09 GW and 7.17 GW, respectively, and the total evaluated energy from the all proposed step were 0.43 GW and 1.87 GW for the 3 ㎞and 1.5 ㎞geographical grid size, respectively.
        34.
        2014.02 KCI 등재 서비스 종료(열람 제한)
        This paper investigates the characteristics of high PM2.5 episodes occurred at Anmyeondo area in spring time, 2009. The monthly mean PM2.5 concentration during April was the highest in the year and especially, high levels of PM2.5 exceeding standard regulation level were sustained consecutively during 5 to 13 April. To analyze more detailed PM2.5 characteristics, numerical simulations were carried out using CMAQ(Community Multi-scale Air Quality) with IPR(Integrated Process Rate) and DDM-3D(Decoupled Direct Method). PM2.5 level was lower in daytime than that in nighttime due to vigorous vertical mixing during daytime. The chemical composition was showed that ratio of primary ion components such as sulfate(SO4 2-), nitrate(NO3 -) and ammonium(NH4 +) were nearly half of total amount of PM2.5. Aerosol and transport process dominantly contributed to PM2.5 concentration in Anmyeondo area and contribution rate of local emissions was nearly zero since Anmyeondo area has rare anthropogenic PM emission sources. DDM-3D analysis result showed that PM2.5 in Anmyeondo area was influenced by emissions from Shanghai and Shandong region of China.
        35.
        2013.10 KCI 등재 서비스 종료(열람 제한)
        A long-term wind resource map was made to provide the key design data for the 2.5 GW Korean West-South Offshore Wind Project, and its reliability was validated. A one-way dynamic downscaling of the MERRA reanalysis meteorological data of the Yeongwang-Gochang offshore was carried out using WindSim, a Computational Fluid Dynamics based wind resource mapping software, to establish a 33-year time series wind resource map of 100 m x 100 m spatial resolution and 1-hour interval temporal resolution from 1979 to 2012. The simulated wind resource map was validated by comparison with wind measurement data from the HeMOSU offshore meteorological tower, the Wangdeungdo Island meteorological tower, and the Gochang transmission tower on the nearby coastline, and the uncertainty due to long-term variability was analyzed. The long-term variability of the wind power was investigated in inter-annual, monthly, and daily units while the short-term variability was examined as the pattern of the coefficient of variation in hourly units. The results showed that the inter-annual variability had a maximum wind index variance of 22.3% while the short-term variability, i.e., the annual standard deviation of the hourly average wind power, was 0.041±0.001, indicating steady variability.
        36.
        2013.06 KCI 등재 서비스 종료(열람 제한)
        In order to analyze the effect of environmental protection on wind energy dissemination quantitatively, the onshore wind resource potential is estimated using Environmental Conservation Value Assessment Map and Korea Wind Resource Map. The onshore wind resource potential of 11 GW is calculated if wind farm development is prohibited within Class 1 area of Environmental Conservation Value Assessment plus 500 m buffer area. Therefore it is worried that environmental protection would be a practical barrier of accomplishing 4,155 thousand TOE target of wind energy dissemination until 2030.
        37.
        2012.02 KCI 등재 서비스 종료(열람 제한)
        The mean wind speed and turbulence intensity profiles in the atmospheric boundary layer were extracted from a LIDAR remote sensing campaign in order to apply for CFD validation. After considering the semi-steady state field data requirements to be used for CFD validation, a neutral atmosphere campaign period, in which the main wind direction and the power-law exponent of the wind profile were constantly maintained, was chosen. The campaign site at the Pohang Accelerator Laboratory, surrounded by 40~50m high hills, with an apartment district spread beyond the hills, is to be classified as a semi-complex terrain. Nevertheless, wind speed profiles measured up to 100m above the ground fitted well into a theoretical-experimental logarithmic-law equation. The LIDAR remote-sensing data of the sub-layer of the atmospheric boundary layer has been proven to be superior to the data obtained by conventional extrapolation of the wind profile with 2 or 3 anemometer measurements.
        38.
        2011.07 KCI 등재 서비스 종료(열람 제한)
        We have established a wind map of Singapore, a city-state characterized its land cover by urban buildings to confirm a possibility of wind farm development. As a simple but useful approximation of urban canopy, a zero-plane displacement concept was employed. The territory is divided into 15 sectors having similar urban building layouts, and zero-plane displacement, equivalent roughness height at each sector was calculated to setup a terrain boundary condition. Annual mean wind speed and mean wind power density map were drawn by a CFD micrositing model, WindSim where Changi International Airport wind data was used as an in-situ measurement. Unfortunately, predicted wind power density does not exceed 80 W/m2 at 50 m above ground level which would not sufficient for wind power generation. However, the established Singapore wind map is expected to be applied for wind environment assessment and urban planning purpose.
        39.
        2010.10 KCI 등재 서비스 종료(열람 제한)
        Three meteor-statistical forecasting models - the transfer function model, the time-series autoregressive model and the neural networks model - were tested to develop a daily forecasting model for Jejudo, where the need and demand for wind power forecasting has increased. All the meteorological observation sites in Jejudo have been classified into 6 groups using a cluster analysis. Four pairs of observation sites among them, all having strong wind speed correlation within the same meteorological group, were chosen for a model test. In the development of the wind speed forecasting model for Jejudo, it was confirmed that not only the use a wind dataset at the objective site itself, but the introduction of another wind dataset at the nearest site having a strong wind speed correlation within the same group, would enhance the goodness to fit of the forecasting. A transfer function model and a neural network model were also confirmed to offer reliable predictions, with the similar goodness to fit level.
        40.
        2010.09 KCI 등재 서비스 종료(열람 제한)
        A case study for the design of a wind farm in complex terrain was carried out using the wind farm site analysis software OpenWind, which has an open-source platform and is free to use. The Youngdeok Wind Farm, constructed on mountainous terrain in Korea, was chosen as a model site; the design process reproduced using OpenWind. A comparison of the positions of the wind turbine derived from the OpenWind optimization process and the current positions were in good agreement. The annual energy production predicted by OpenWind compared with the prediction by the micrositing software, WindSim, were also validated to within 1%. Therefore, it was confirmed that OpenWind can be used for a practical wind farm design project. It is also anticipating that this paper will provide a prototype process for the design of a wind farm site and offer a database for the post-evaluation of a constructed wind farm in Korea.
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