Lee, U.-J.; Cho, H.-Y.; B.W., and Ko, D.-H., 2023. Joint probability distribution of significant wave height peak period using Gaussian copula method. In: J.L.; H.; Min, B.I.; Chang, J.-I.; G.T.; Yoon, J.S., J. (eds.), Multidisciplinary Approaches to Coastal Marine Management. Journal Research, Special Issue No. 116, pp. 96-100. Charlotte (North Carolina), ISSN 0749-0208. In this study, the joint was estimated height-peak data observed for 3 years stations along coast Korea, an environmental...

Various mathematical models have been proposed to estimate the vertical tidal current profile. However, because parameters of these depend on specific site conditions such as seabed and viscosity, it is recommended them using field-measured data. In particular, energy sites with fast velocities exhibit different profile characteristics from general sea areas, making essential profiles data for practical purposes. this study, layered currents were measured over two months an acoustic Doppler...

As global energy consumption continues to increase, the negative impact of warming also grows. Therefore, eco-friendly policy is being established all over world. Korea’s problems are further complicated by country’s high dependence on sourced overseas. Korean evolving rapidly address these problems. Korea has begun phase out nuclear power and focusing developing new sources renewable energy. So there been substantial interest in development ocean Of technologies, tidal current closest...

When the steam is used as working fluid in machinery, different from other gases air, phase transition (steam condensation) can occur and it affects not only flow fields, but also machine performance & efficiency. Therefore, considering phenomena CFD calculation required to achieve accurate prediction of non-equilibrium wet-steam model needed simulate realistic condensing flow. In this research, implemented on in-house code(T-Flow), fields including convergent-divergent nozzle are studied...

우리나라 연안 조위자료의 결측양상을 분석 제시하였다. 결측구간은 결측정보지시행렬을 이용하여 전체적인 파악할 수 있도록 도시하였으며, 시간적 공간적인 결측비율도 분석하여 전반적으로 조위의 결측비율은 낮은 수준이나, 결측이 특정 조위관측소에 집중되는 경향을 보이고 있다. 또한 연속적인 결측자료 발생간격에 대한 자기상관함수를 분석한 결과, 결측은 무작위적으로 발생하고 있는 것으로는 파악되었다. The missing data patterns of tidal elevation in Korean coasts are analysed and provided. interval the is displayed for all stations using indicator matrix order to identify overall pattern. spatial temporal rates also estimated. total rate low. However, most mainly derived...

In this study, waves were defined using the water surface elevation data observed from HeMOSU-1 and 2 marine meteorological observation towers installed on west coast of Korea, correlation analysis was performed between wave parameters. The height period determined wave-train method spectrum method, relationship parameters calculated compared with previous study. relation representative heights, most coefficients showed a difference less than 0.1% in error rate to maximum up 29%. addition,...

Ko, D.-H. and Lee, U.-J., 2023. Reliability analysis of offshore wind structures considering the Korean met-ocean conditions. In: J.L.; H.; Min, B.I.; Chang, J.-I.; Cho, G.T.; Yoon, J.-S., J. (eds.), Multidisciplinary Approaches to Coastal Marine Management. Journal Research, Special Issue No. 116, pp. 603-607. Charlotte (North Carolina), ISSN 0749-0208. IEC DNV documents, which are developed for design turbines, have been based on experiences industry. Moreover, documents adopt reliability...

Tidal power is a technology that generates electricity by utilizing tidal current energy, and in recent years, with the advancement of technology, it has reached stage real sea performance test. However, case Korea, there lack construction experience equipment, work fast flows such as Uldolmok region involves various risk factors. In order to establish measures reduce these factors, Korea’s Occupational Safety Health Act recommends performing assessment identify manage factors may occur...

Many mathematical models have been proposed to estimate vertical tidal current profiles. However, as previous studies shown that energy sites different characteristics in their profiles, it is necessary the profiles from field-measured data for practical purposes. In this study, we measured layered currents over two months using an acoustic Doppler profiler (ADCP) analyze of at Jangjuk Strait, a candidate site energy. As result, power law parameter α and bed roughness β were estimated...

Along with the growing interest in renewable energy development, Korea’s west coast is one of favorable regions for tidal power. Tidal power using barrages that work like hydroelectric dams a representative method through long-term operation, but promotion projects being delayed or stopped due to impacts on ecological changes, reproduction, water column processes and hydrology. In order reduce high construction cost environmental problems caused by barrages, this study, field experiments...

Cho, H.-Y.; Choi, H.-J.; Jeong, S.-T., and Ko, D.-H., 2018. Relationship between wave height sampling interval: revisiting individual analysis method. In: Shim, J.-S.; Chun, I., Lim, H.S. (eds.), Proceedings from the International Coastal Symposium (ICS) 2018 (Busan, Republic of Korea). Journal Research, Special Issue No. 85, pp. 1136–1140. Coconut Creek (Florida), ISSN 0749-0208.Wave is one most important physical factors in coastal environment. In general, it estimated using water surface...

본 연구에서는 조류발전시스템의 설계근거(design basis) 작성을 위해 2003년부터 2019년까지 장죽수도 인근해역의 장기 파랑 후측 자료를 이용하여 극치파랑조건을 분석하였다. 장기파랑자료의 극치모델로는 Weibull-3 분포형을 사용하였으며, 매개변수 추정법으로는 확률가중모멘트법과 최소자승법을 사용하였다. 또한 극치분포함수의 적합도 검정을 95%의 신뢰수준으로 K-S 검정법(Kolmogorov-Smirnov test)을 POT(Peaks-Over-Threshold) 기법을 재현기간별 설계파고를 산정하였다. 그 결과, 자료는 분포형에 잘 접합하는 것으로 나타났으며, 확률가중모멘트법을 추정한 극치파고가 최소자승법으로 극치파고보다 높게 산정되었다. 재현주기별 극치파고에 상응하는 파주기를 산정하기 파고와 파주기에 대한 관계식을 추정하였다.

In this study, a smoothing method was applied to improve the accuracy of peak wave period estimation using water surface elevation observed from Oceanographic and Meteorological Observation Tower located on west coast Korean Peninsula. Validation application performed variance total amount energy, then effect analyzed. As result analysis, correlation coefficient between energy 0.9994, confirming that there no problem in applying method. Thereafter, as reviewing smoothing, it found be reduced...

다양한 목표 ê³ ë„ì—ì„œì˜ 풍속 ì¶”ì •ì€ í•´ìƒí’ë ¥ 구조물 설계 및 풍파 • 등의 분야에서 매우 중요한 요소이다. 그러나 관측 자료가 특ì 도에 í•œì •ë˜ì–´ 있기 때문에 다른 ì¼ë°˜ì ìœ¼ë¡œ 사용되는 연직 분포함수와 í‰ê· ì ì¸ 매개변수를 이용하여 •í•œë‹¤. 본 연구에서는 HeMOSU-1 관측타워의 도에서 ì¸¡ì •í•œ 자료를 Power 함수, 대수함수의 •í•˜ê³ ê·¸ 변동 양상을 분석하였다. 매개변수 ê²°ê³¼,...

In this study, wave spectrum data were calculated using the water surface elevation observed at 5Hz intervals from HeMOSU-2 meteorological tower installed on west coast of Korea, and parameters estimated data. For all significant height ranges, peak enhancement parameter (γopt) JONSWAP scale (α) shape (β) modify BM based spectrum, distribution each was confirmed. As a result analysis, to be 1.27, which is very low compared previously proposed 3.3. And in range heights, shown as combined...

As problems such as difficulties in securing stable energy resources and global warming due to the emission of greenhouse gases use fossil fuels have emerged, interest development renewable is increasing. Since tidal phenomenon has a regularity that occurs regularly with certain period, it possible predict accurately advance, which advantage terms recovery. Therefore, various methods been devised utilize tide an source. Tidal power using barrages representative method widely operated, but...

In this study, a smoothing method was applied to improve the accuracy of peak wave period estimation using water surface elevation data collected from two oceanographic and meteorological observation towers situated on western coast Korean Peninsula. The effectiveness validated by assessing variance total energy. Subsequently, we examined impact application. results our analysis revealed reduction approximately 27% in comparison confidence interval initially estimated spectrum upon applying...