Fig 5 - uploaded by Hyun-Goo Kim
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에 보정하지 않은 라이다 풍속과 RSCT로 보정한 풍속 의 차이를 바람장미 형태로 도시하였다. NW-N 구간과 그 대칭 인 SE-S 구간은 음의 풍속차를 보이는데, 이는 지형에 의한 풍 속의 감속으로 라이다 측정풍속이 과소예측 되었음을 의미한 다. 반대로 SW-W 구간은 양의 풍속차, 즉 라이다 측정풍속이 과대예측 되었음을 의미한다. 라이다를 현재의 평탄지형(IC 복잡지수 경사도 0.67) 지점이 아니라 봉대산 북측 사면의 복잡지형(IC 복잡지수 경사도 1.58) 내 대조지점에 설치하였을 경우, RSCT에 의한 풍속오차의 MAE(Mean Absolute Error)는 평탄지형에서는 0.03m/s이었으 나 대저지점에서는 0.08m/s로 3배가 증가함을 확인하였다.
Source publication
In order to develop an offshore wind farm by reusing the surplus grid connection capacity after the closure of the Gori Nuclear Power Plant, this paper proposes a method of assessing offshore wind resources with the short-term lidar measurement data obtained from the nearby onshore area. For this purpose, the correction of the lidar measurement err...
Citations
... PCA로 분석한 DTM의 주성분 PC1, PC2, PC3는 각각 진동제 어(vibration control), 공기역학/교량(aerodynamics/bridge), 고 층건물(high-rise building)로 나타났으며, 이들의 설명력은 5.2% 6.8%이다. (22) Topic 7은 풍력자원평가(wind resource assessment)와 (23,24) 바 람지도(wind map)가 (25,26) 핵심 키워드이며, Topic 8은 건물진 동의 능동제어가 (27,28) 핵심 키워드이다. ...
This study aimed to compare and evaluate the suitability of topic modeling techniques such as Latent Semantic Analysis (LSA) and Latent Dirichlet Allocation (LDA) by applying to the research subject extraction of the Journal of the Wind Engineering Institute of Korea. In order to evaluate the similarity between classified topics, a method of correlation analysis using a document-topic-matrix was proposed. LDA, which uses the probability of combinations of specific words, employed more than twice as many words to compose a topic than LSA, which extracts topics from the feature vectors of the document-word-matrix. As a result, the topics extracted by LDA were more independent than those extracted by LSA. In summarizing the research subjects of the journal, 'building' and 'bridge' were taken as the 'research objective' and investigated to determine 'wind speed', 'wind load', and 'vibration control', which constitute the 'research purpose', while 'wind tunnel test' or 'numerical method' were used as the 'research method'. It is concluded that topic modeling should be improved in a way that reflects the use of words by defining the research subject as a structural combination of 'research subject', 'research purpose' and 'research method'.
To determine the wind turbine class in the offshore of the Korean Peninsula, the reference wind speed for a 50-y return period at the hub height of a wind turbine was estimated using the reanalysis data sets. The most recent reanalysis data, ERA5, showed the highest correlation coefficient (R) of 0.82 with the wind speed measured by the Southwest offshore meteorological tower. However, most of the reanaysis data sets except CFSR underestimated the annual maximum wind speed. The gust factor of converting the 1 h-average into the 10 min-average wind speed was 1.03, which is the same as the WMO reference, using several meteorological towers and lidar measurements. Because the period, frequency, and path of typhoons invading the Korean Peninsula has been changing owing to the climate effect, significant differences occurred in the estimation of the extreme wind speed. Depending on the past data period and length, the extreme wind speed differed by more than 30% and the extreme wind speed decreased as the data period became longer. Finally, a reference wind speed map around the Korean Peninsula was drawn using the data of the last 10 years at the general hub-height of 100 m above the sea level.
