• 대한원격탐사학회:학술대회논문집
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• 대한원격탐사학회 2006년도 Proceedings of ISRS 2006 PORSEC Volume I
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• pp.394-397
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• 2006

Gridded products of surface wind/wind-stress over the world ocean have been constructed by using satellite scatterometer as the Japanese Ocean Flux data sets with Use of Remote-sensing Observation (J-OFURO) data. Our previous validation study in the tropical Pacific using TAO/Triton and NDBC buoys revealed high reliability of our products. In this study, the Kuroshio Extension Observatory (KEO) buoy data are used for validation of other gridded wind-stress products including the NCEP-1 and 2 in the western North Pacific region where there have been few in-situ data. Results reveal that our J-OFURO product has almost zero mean difference and smallest root-mean-square (RMS) difference, while the NCEP-1 and 2 ones significantly positive biases and relatively high RMS difference. Intercomparison between the J-OFURO and NCEP products in a wide region of the North Pacific covered by the westerly winds exhibits that the NCEPs have larger magnitudes in the wind stress than the J-OFURO's, suggesting overestimation of the NCEPs.

• 한국해양학회지
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• 제27권1호
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• pp.1-10
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• 1992

10년간(1978~1987) 매일 2회 발행된 전기도를 근거로 Cardone Model을 이용한 한 국근해에서의 해상풍을 구하고 이를 근거로 월평균 wind-stress와 wind-stress curl의 분포를 계산하였다. 계산된 해상풍과 실측자료와의 비교를 위해 일본기상청 관측부 표 (Buoy 6) 자료와 비교한 결과 풍향 및 풍속이 매우 일치함을 보였다. 특히 계산된 wind-stress의 평균값은 기존의 값들에 비해서 동해의 경우 약 2배 정도로 나타나고 있다. Wind-stress의 분포특성은 서행의 경우는 $120^{\circ}{\;}~{\;}125^{\circ}{\;}E$를 중심으로 동.서로 부호가 서로 반대인 값을 가지며 특히 중국연안은 여름철을 제외한 전월에 음의 값을 나타낸다. 한편 동해(일본해)는 북부해역의 양의 값과 남부해역의 음의 값으로 그 특 징을 보이나 북부해역의 경우 동해의 최북단 및 원산만 부근에서 최대의 양의 값이 나 타나고 있다.

• 한국수산과학회지
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• 제21권6호
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• pp.341-350
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• 1988

The wind stress distribution over the East Sea of Korea was obtained from the shipboard observations of the Fisheries Research and Development Agency along the serial observation lines. These monthly and annual mean wind stress distributions were put into the simplified interface model which describes the latitudinal variations of the upper-layer thickness as function of the curl of the wind stress. The observed variations of the surface, zonally averaged winds indeed caused the upper-layer flow convergent and divergent at the latitudes that produced a tone of thick upper-layer or a deep permanent thermocline and the shallower depth with divergence. Thus, the wind field contributes positively to maintain the almost time-independent distribution of the interface of 'saddle like' feature in north-south direction over the study area.

• 한국해양학회지
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• 제19권1호
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• pp.36-43
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• 1984

複雜한 沿岸地形 및 水深變化를 考慮한 黃海 및 東支那海의 三次元 水動力學的 羞恥모델을 開發하여 定常均一風의 應力에 의한 海流의 手織分布를 算定하였다. 北西風 및 南西風의 秒速 약 10m에 該當하는 海面應力 1.6dyne/$\textrm{cm}^2$에 의한 陸棚體系의 反應을 調査하기 위한 手織實驗에서 動的 循環形態를 提示하고 檢討하였다.

• 한국수산과학회지
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• 제26권6호
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• pp.538-548
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• 1993

한국 동해 연안역 해수순환 및 수온분포에 대한 바람응력의 효과에 관하여 검토하였다. 동해상의 바람응력은 국립수산진흥원 정선관측 바람자료 및 일본기상청 Buoy No. 6에서의 10년간($1978{\sim}1987$)의 약 5,100개의 바람 관측자료를 사용하여 계산하였다. 여름과 겨울의 계절풍의 전환에 따른 에크만 수송의 변화가 대한해협에서의 대마난류 수송량에 미치는 영향을 정량적으로 평가하였다. 특히 동해에서의 평균적인 바람응력의 회전성(wind stress curl) 값이 음이 되는 사실에서 울릉도 근해의 난수층의 형성에 부분적으로 도움이 됨을 알았다. 한편, 동해 난수층의 분포를 단순화된 3층 경계면모델을 적용하여 설명하였다.

• Wind and Structures
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• 제9권4호
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• pp.255-270
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• 2006

Several analytical procedures available in literature, for the evaluation of wind induced fatigue damage of structures, either assume the wide band random stress variations as narrow band random process or use correction factors along with narrow band assumption. This paper compares the correction factors obtained using the Rainflow Cycle (RFC) counting of the measured stress time histories on a lamp mast and a lattice tower, with those evaluated using different frequency domain methods available in literature. A Bi-modal spectral method has been formulated by idealising the single spectral moment method into two modes of background and resonant components, as considered in the gust response factor, for the evaluation of fatigue of slender structures subjected to "along-wind vibrations". A closed form approximation for the effective frequency of the background component has been developed. The simplicity and the accuracy of the new method have been illustrated through a case study by simulating stress time histories at the base of an urban light pole for different mean wind speeds. The correction factors obtained by the Bi-modal spectral method have been compared with those obtained from the simulated stress time histories using RFC counting method. The developed Bi-modal method is observed to be a simple and easy to use alternative to detailed time and frequency domain fatigue analyses without considerable computational and experimental efforts.

• 한국복합재료학회:학술대회논문집
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• 한국복합재료학회 2002년도 추계학술발표대회 논문집
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• pp.5-9
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• 2002

This paper presents a method and procedure for stress analysis and sizing in development of structures of a large composite wind turbine blade. Structural requirement of IEC standard was reviewed to set up appropriate analysis method and procedure. Several structural layouts were examined in a viewpoint of a large scale wind turbine blade. For the critical load cases, stress analysis were performed using finite element method. Stacking sequence and thickness of a laminate for each part and location were determined considering stress levels and producibility. Nonlinear geometric analysis was performed to check stability problem due to local buckling of a skin structures.

• 한국산업정보학회논문지
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• 제18권2호
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• pp.13-18
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• 2013

The authors designed a high temperature superconductor (HTS) racetrack coil for a 10 MW class superconducting synchronous wind turbine generator. The designed HTS racetrack coil was analyzed by an electromagnetic finite element method (FEM) to determine the magnetic field distribution, inductance, stress, etc. This paper describes the stress analysis and structure design result of the HTS racetrack coil for 10 MW class superconducting synchronous wind turbine generators, considering orthotropic material properties, a large magnetic field, and the resulting Lorentz force effect. Insulated HTS racetrack coils and no-insulation HTS racetrack coils were also considered. According to the results of the stress analysis, the no-insulation HTS racetrack coil results were better than the insulated HTS racetrack coil results.

• 한국해양환경ㆍ에너지학회지
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• 제4권2호
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• pp.35-42
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• 2001

한국 남동해역 취송순환에서의 부정확한 외력의 바람응력 문제에 대한 최적화 방법의 유용성에 관하여 검토하였다. 바람응력은 모델 및 수치적 정식화 과정에서 상층 경계조건 및 외력항으로 고려되었다. 그리고 바람응력 평가에 대한 최적화 방법의 적용성 및 모델변수의 초기값 추정치의 중요성을 검토하였다. 최적화 연구로부터 동해 남부해역의 취송순환에 관한 동한난류의 수송량 변화 및 통해 난수층의 형성과 분포특성을 바람응력, 바람응력 회전성 및 상층두께의 변동으로부터 파악할 수 있음을 확인하였다.

• Ocean Science Journal
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• 제42권2호
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• pp.89-102
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• 2007

The surface circulation of northern South China Sea (hereafter SCS) for the period 1987-2005 was studied using the data of more than 500 satellite-tracked drifters and wind data from QuikSCAT. The mean flow directions in the northern SCS except the Luzon Strait (here after LS) during the periods October_March was southwestward, and $April{\sim}September$ northeastward. A strong northwestward intrusion of the Kuroshio through the LS appears during the $October{\sim}March$ period of northeasterly wind, but the intrusion became weak between April and September. When the strong intrusion occurred, the eddy kinetic energy (EKE) in the LS was $388cm^2/s^2$ which was almost 2 times higher than that during the weak-intrusion season. The volume transport of the Kuroshio in the east of the Philippines shows an inverse relationship to that of the LS. There is a six-month phase shift between the two seasonal phenomena. The volume transport in the east of the Philippines shows its peak sis-month earlier faster than that of the LS. The strong Kuroshio intrusion is found to be also related to the seasonal variation of the wind stress curl generated by the north easterly wind. The negative wind stress curl in the northern part of LS induces an anticyclonic flow, while the positive wind stress curl in the southern part of LS induces a cyclonic flow. The northwestward Kuroshio intrusion in the northern part of LS happened with larger negative wind stress curl, while the westward intrusion along $20.5^{\circ}N$ in the center of the LS occurred with weaker negative wind stress curl.