평활화 기법을 이용한 파랑 첨두주기 최적 추정
Optimal Estimation of the Peak Wave Period using Smoothing Method
1
조회
0
다운로드
1
인용
0
참고문헌
키워드
초록
본 연구에서는 한반도 서해안에 위치한 해상기상관측타워에서 관측된 수면변동자료를 이용하여 첨두주기산정의 정확도 향상을 위한 평활화 기법을 적용하였다. 평활화 기법 적용에 대한 검증은 파형의 분산값과 관측 자료의 에너지 총량을 통해 수행하였으며, 이후 평활화 적용에 대한 영향을 분석하였다. 분석결과, 파형의 분산값과 관측자료의 에너지 총량의 상관계수는 0.9994로 나타났으며, 해당 기법 적용에 문제가 없음을 확인하였다. 이후, 평활화영향 검토를 수행한 결과, 기존 추정 스펙트럼의 신뢰구간에 비해 최대 26% 감소하는 것으로 나타남으로서, 추정되는 첨두주기의 정확도가 향상됨을 확인하였다. 평활화 적용으로 인하여 4~6초 사이에서 확률밀도는 통계적으로 유의미한 차이가 발생하는 것으로 나타났다. 또한, 최적 평활화를 위해 통계적 기법을 이용하여 유의파고 범위에 따른적정 평활화 개수를 산정하였으며, 평활화 개수는 유의파고가 작아짐에 따라 불안정한 스펙트럼 형상에 의해 증가하는 것으로 나타났다.
Abstract
In this study, a smoothing method was applied to improve the accuracy of peak wave period estimation using the water surface elevation observed from the Oceanographic and Meteorological Observation Tower located on the west coast of the Korean Peninsula. Validation of the application of the smoothing method was performed using variance of the surface elevation and total amount wave energy, and then the effect on the application of smoothing was analyzed. As a result of the analysis, the correlation coefficient between variance of the surface elevation and total amount wave energy was 0.9994, confirming that there was no problem in applying the method. Thereafter, as a result of reviewing the effect of smoothing, it was found to be reduced by about 4 times compared to the confidence interval of the existing estimated spectrum, confirming that the accuracy of the estimated peak wave period was improved. It was found that there was a statistically significant difference in probability density between 4 and 6 seconds due to the smoothing application. In addition, for optimal smoothing, the appropriate number of smoothings according to the significant wave height range was calculated using a statistical technique, and the number of smoothings was found to increase due to the unstable spectral shape as the significant wave height decreased.
참고문헌 (23)
- Aranuvachapun, S., "Parameters of JONSWAP spectral model for surface gravity waves—II. Predictability from real data", Ocean engineering, 14(2), pp.101~115 (1987)
- Brigham, E.O., "The fast Fourier transform and its applications" (1988), Prentice-Hall, Inc
- Casas Prat, M., "Overview of ocean wave statistics", ~ (2008)
- Cho, H. Y., "Relationship between wave height and sampling interval : revisiting individual wave analysis method", Journal of Coastal Research, 85(10085), pp.1136~1140 (2018)
- 조홍연, "A study on the optimal equation of the continuous wave spectrum", International Journal of Naval Architecture and Ocean Engineering, 7(6), pp.1056~1063 (2015), 대한조선학회
- 최혁진, "MATLAB을 이용한 개별파 분석 프로그램 개발", 한국해안·해양공학회논문집, 29(5), pp.239~246 (2017), 한국해안,해양공학회
- Goda, Y., "Random seas and design of maritime structures (Vol. 33)" (2010), World Scientific Publishing Company
- Hoekstra, G. W., "Mathematical description of the standard wave analysis package", The Oceanographic Company of the Netherlands bv: Castricum, ~ (1994)
- Horikawa, K., "Coastal Engineering, An Introduction to Ocean Engineering" (1978), Univ. of Tokyo Press
- 이욱재, "HeMOSU-1&2의 파랑 관측 자료를 이용한 파랑 변수 간 상관관계 분석", 한국해안·해양공학회논문집, 33(4), pp.139~147 (2021), 한국해안,해양공학회[DOI]
- 이욱재, "HeMOSU-2 관측 자료를 이용한 파랑 스펙트럼 매개변수 추정 및 분석", 한국해안·해양공학회논문집, 33(6), pp.217~225 (2021), 한국해안,해양공학회[DOI]
- Liu, P. C., "Is the wind wave frequency spectrum outdated", Ocean Engineering, 27(5), pp.577~588 (2000)
- Liu, P. C., "Using wavelet spectrum analysis to resolve breaking events in the wind wave time series. In Annales Geophysicae", Copernicus GmbH, 22(10), pp.3335~3345 (2004)
- Mizuguchi, M., "Individual wave analysis of irregular wave deformation in the nearshore zone", Coastal Engineering Proceedings, 18, pp.32~32 (1982)
- Development of wave train analysis package: WAVETRAP, "Nishi, R.", The Research Report of the Faculty of Engineering, Kagoshima Univ, 179~198 (1997)
- Pierson, W. J., "The power spectrum analysis of ocean‐wave records", Eos, Transactions American Geophysical Union, 33(6), pp.834~844 (1952)
- Rodriguez, G. R., "The bivariate distribution of wave height and periods in mixed sea states", Journal of Offshore Mechanics and Arctic Engineering, 121(2), pp.102~108 (1999)
- Soares, C. G., "Probability distributions of wave heights and periods in combined sea-states measured offthe Spanish coast", Ocean engineering, 52, pp.13~21 (2012)
- Stansell, P., "Effect of sampling rate on wave height statistics", Ocean Engineering, 29(9), pp.1023~1047 (2002)
- Energy spectra in shallow US coastal waters, "Thompson, E.F.", US Army corps of engineers, Coastal engineering research center, ~, pp.Technical paper, 80-2 (1980)
- Thomson, R. E., "Data analysis methods in physical oceanography" (2014), Newnes
- Wand, M. P., "Kernel Smoothing" (1994), Chapman and Hall
- Zheng, G., "On the improvements to the wave statistics of narrowbanded waves when applied to broadbanded waves", Journal of Geophysical Research: Oceans, 111(C11) (2006)[DOI]