• 한국해양환경ㆍ에너지학회지
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• 제15권4호
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• pp.357-362
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• 2012

파랑 관측 자료는 인간이 바다에서 활동을 하는데 있어 아주 중요한 정보임에도 불구하고, 국내에서는 파랑 관측 장비에 대한 기술 개발이나 연구가 부족한 형편이다. 본 연구는 Single GPS를 이용한 파고 관측 자료의 정확한 품질을 평가하기 위해 장기간 비교 관측을 실시하였다. 가속도센서(Hippy-40)와 GPS센서(Mose-1000)의 비교 관측 결과, 유의파고의 상관계수는 0.997이며, 유의파 주기의 상관계수도 0.990으로 거의 일치하고 있다. 또한 BIAS에서도 유의파고는 0.014 m, 유의파주기는 -0.212초로 거의 차이가 없는 것으로 평가되었다. 이러한 결과는 GPS를 이용한 파고 관측 자료의 품질이 아주 우수한 것으로 평가되는 것이다.

• 동력기계공학회지
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• 제13권2호
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• pp.63-70
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• 2009

This paper discusses the influence on long-tenn predictions of the ship response in ocean by using the Global Wave Statistics data, GWS, and wave information from the remote sensing satellites. GWS's standard scatter diagrams of significant wave height and zero-crossing wave period are suggested to be corrected to a round number of 0.01/1000 fitted with a statistical analytic model of the conditional lognormal distribution for zero-crossing wave period. The GEOSAT satellite data are utilized which presented by I. R. Young and G. J. Holland (1996, named as GEOSAT data). At first, qualities of this data are investigated, and statistical characteristic trends are studied by means of applying known probability distribution functions. The wave height data of GEOSAT are compared to the data observed onboard merchant ships, the data observed by measure instrument installed on the ocean-going container ship and so on. To execute a long-tenn prediction of ship response, joint probability functions between wave height and wave period are introduced, therefore long-term statistical predictions are executed by using the functions.

• 한국지진공학회논문집
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• 제18권2호
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• pp.89-94
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• 2014

Spatial variations of a seismic wave are mainly wave passage and wave scattering. Wave passage effect is produced by changed characteristics of exciting seismic input motions applied to the bedrock. Modified input motions travel horizontally with time differences determined by apparent shear wave velocity of the bedrock. In this study, wave passage effect on the seismic response of a structure-soil system is investigated by modifying the finite element software of P3DASS (Pseudo 3-Dimensional Dynamic Analysis of a Structure-soil System) to apply inconsistent (time-delayed) seismic input motions along the soft soil-bedrock interface. Study results show that foundation size affected on the seismic response of a structure excited with inconsistent input motions in the lower period range below 0.5 seconds, and seismic responses of a structure were decreased considerably in the lower period range around 0.05 seconds due to the wave passage. Also, shear wave velocity of the bedrock affected on the seismic response of a structure in the lower period range below 0.3 seconds, with significant reduction of the seismic response for smaller shear wave velocity of the bedrock reaching approximately 20% for an apparent shear wave velocity of 1000m/s at a period of 0.05 seconds. Finally, it is concluded that wave passage effect reduces the seismic response of a structure in the lower period range when the bedrock under a soft soil is soft or the bedrock is located very deeply, and wave passage is beneficial for the seismic design of a short period structure like a nuclear container building or a stiff low-rise building.

• 센서학회지
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• 제17권6호
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• pp.454-461
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• 2008

This embedded module measures significant wave height and zero crossing periods through spectral energy from a record of time series heave motion. An ARM7TDMI core microcontroller serves as the main control unit which performs the appropriate control and signal conditioning. Monitored wave characteristic is transmitted with satellite modem. Mathematical equations on signal conditioning and experiments procedures are documented in this paper.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2011년도 춘계학술대회 초록집
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• pp.164.1-164.1
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• 2011

Previously, many researchers assessed nearshore wave energy in two ways. The first is a simulation with respect to the offshore wave time series to validate the wave buoy data and the wave model results, and the other is to simulate the representative waves of typical seasonal wave conditions. The former requires enormous computational time and effort. The latter yields inspection on the patterns for the spatial and temporal distribution of nearshore wave energy but tends to underestimates the amount of wave energy in the nearshore region owing to the correlation between the significant wave height and wave period. $\ddot{O}$zger et al. (2004) derived the stochastic wave energy formulation by introducing a correction factor explicitly in terms of the covariance of the wave energy and significant wave height. In this study, a correction factor was applied for the assessment of nearshore wave energy obtained by numerical simulation of wave transformation with respect to representative waves.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2009년도 춘계학술대회 논문집
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• pp.615-619
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• 2009

This paper is investigated to variation of wave power generation operation rate, operating capacity and output with the wave conditions represented by wave height-period window. By the use of the long-term wave data from 1979 to 2002 which is provided by Korea Ocean Research & Development Institute(KORDI), we calculated the monthly variation of significant wave height(Hs), zero-up crossing period(Tz) and distribution of wave appearance rate. And using the same wave data, it was charted the Hs-Tz and wave-energy scatter diagrams.

• 대한원격탐사학회지
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• 제39권4호
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• pp.441-458
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• 2023

Tropical cyclones frequently occur in the Southwest Pacific Ocean and are considered one of the driving forces for coastal alterations. Therefore, this study investigates the frequency and intensity of tropical cyclonesfrom 2000 to 2021 and their influence on the surface winds and wave conditions around the atoll nation Tuvalu. Cyclone best-track and ERA5 single-level reanalysis data are utilized to analyze the condition of the surface winds, significant wave heights, mean wave direction, and mean wave period. Additionally, the scatterometer-derived wind information was employed to compare wind conditions with the ERA5 data. On average, nine cyclones per year originated here, and the frequency increased to 11 cyclones during the last three years while the intensity decreased by 25 m/s (maximum sustained wind speed). Besides, a total of 14 cyclones were observed around Tuvalu during the period from 2015 to 2021, which showed an increase of 3 cyclones compared to the preceding period of 2001 to 2007. During cyclones, the significant wave height reached the highest 4.8 m near Tuvalu, and the waves propagated in the east-southeast direction during most of the cyclone events (52%). In addition, prolonged swells with a mean wave period of 7 to 11 seconds were generated in the vicinity of Tuvalu, for which coastal alteration can occur. After this preliminary analysis, it was found that the waves generated by cyclones have a crucial impact in altering the coastal area of Tuvalu. In the future, remotely sensed high-resolution satellite data with this wave information will be used to find out the degree of alterations that happened in the coastal area of Tuvalu before and after the cyclone events.

• Geomechanics and Engineering
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• 제12권6호
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• pp.949-963
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• 2017

The main purpose of the current study is to develop the new coefficients for consideration of soil-structure interaction effects to find the elevated tank natural period. Most of the recommended relations to find the natural period just assumed the fixed base condition of elevated tank systems and the soil effects on the natural period are neglected. Two different analytical systems considering soil-structure- fluid interaction effects are recommended in the current study. Achieved results of natural impulsive and convective period, concluded from mentioned models are compared with the results of a numerical model. Two different sets of new coefficients for impulsive and convective periods are developed. The values of the developed coefficients directly depend to soil stiffness values. Additional results show that the soil stiffness not only has significant effects on natural period but also it is effective on liquid sloshing wave height. Both frequency content and soil stiffness have significant effects on the values of liquid wave height.

• 한국해안·해양공학회논문집
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• 제35권4호
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• pp.84-94
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• 2023

재현기간에 따른 설계주기 추정에는 일반적으로 파고-주기 관계곡선을 이용한다. 본 연구에서는 설계주기 추정을 위한 파고-주기 관계곡선의 매개변수를 선형, 로버스트 선형, 비선형 함수를 이용하여 추정하고 그 계수를 비교-평가하였다. 매개변수 추정에 사용한 자료는 해양수산부(2019) 설계파고 추정에 사용한 연 최대 파고-주기 자료이며, 태풍, 비태풍 조건으로 구분하여 매개변수 추정에 이용하였다. 추정 매개변수는 해역의 지점에 따라 뚜렷한 차이를 보였으며, 추정기법의 경우에는 태풍 조건의 자료의 경우 비선형과 선형 기법이 큰 차이를 보이고 있는 것으로 파악되었다. 또한 SPM 공식과 GODA 공식을 평균하여 추정하는 Suh et al.(2008, 2010) 제안 방법은 절편 매개변수는 과소추정, 경사 매개변수는 과대 추정하는 것으로 파악되었으며, 해역의 국지적인 특성 반영에는 한계가 있는 것으로 판단된다.

• Journal of the Korean Data Analysis Society
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• 제20권6호
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• pp.2941-2951
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• 2018

본 연구는 해양기상관측자료인 평균 풍속, 평균 기압, 평균 상대습도, 평균 기온, 평균 수온, 평균 최대파고, 평균 유의파고, 최고 유의파고, 최고 최대파고, 평균 파주기, 최고 파주기 등의 요인들이 꽃게의 출하건수에 미치는 영향을 음이항 회귀모형을 통해 확인하고 모형적합을 시도하였다. 염분과 수온이 갑각류의 성숙 및 산란에 영향을 미치며, 특히 수온은 성장에 관여하는 대사 작용에 영향을 끼친다고 알려져 있고 최근 지구온난화로 인해, 얼음이 녹으면서 바다의 유의, 최대, 평균파고와 파주기, 그리고 수온까지 영향을 미치고 있어 꽃게 출하건수를 예측하는데 있어 중요한 변수라고 생각할 수 있다. 분석결과 꽃게의 출하건수에 영향을 주는 요인은 평균 풍속, 평균 기압, 평균 상대습도, 평균 해수온도, 최대 파고, 평균 파주기, 최대 파주기로 결정되었다. 꽃게의 출하건수는 평균 풍속, 평균 기압, 평균 상대습도, 평균 해수온도, 평균 파주기가 높을수록 증가하는 경향을 보이고 있고, 최대 파고, 최대 파주기가 낮을수록 꽃게의 출하건수는 증가하는 경향을 보이고 있었다.