• Proceedings of the Korea Committee for Ocean Resources and Engineering Conference
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• 2004.11a
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• pp.96-101
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• 2004

When the wind blows hard, most waves are breaking in sea. Breaking waves occur, exceeding limitation of wave steepness(wave height/wave length=l/7). Because a wave of single angular frequency couldn't generate the breaking phenomena at two dimensional ocean engineering basin, the breaking wave can be generated by the superposition of waves with various angular frequencies. We research how are the particle kinematics in the breaking wave and the magnitude of the breaking wave exciting force. We compare the force in a regular wave which has same specifications(wave height, period and length) as the breaking wave. Also the experimental results of wave exciting force and particle velocity are investigated by comparison on the analytic results using the potential theory.

• Structural Engineering and Mechanics
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• v.60 no.2
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• pp.193-209
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• 2016

In this study, wave force tests were carried out for the four types of offshore support structures with scale factor 1:25 and wave forces to the support structure shapes were investigated. As the results of this study, it was found that, as the wave period increased at the normal wave condition, wave force decreased for the most cases. Extreme wave force was affected by the impact wave force. Impact wave force of this study significantly effect on Monopile and slightly on GBS and Hybrid type. Accordingly, Hybrid type indicated even lower wave force at the extreme and irregular wave conditions than the Monopile although Hybrid type indicated higher wave force at the normal wave condition of the regular wave because of the larger wave area of wave body. In respects of the structural design, since critical loading is extreme wave force, it should be contributed to improve structural safety of offshore support structure. However, since the impact wave force has nonlinearity and complication dependent on the support structure shape, wave height, wave period, and etc., more research is needed to access the impact wave force for other support structure shapes and wave conditions.

• Proceedings of the Korea Committee for Ocean Resources and Engineering Conference
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• 2001.05a
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• pp.216-221
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• 2001

In this paper, statistical properties of waves in the sea area of Pohang, Korea are examined absed on 1998-1999's wave data from directional wave buoy which is located Pohang(Janggigog). Wave data aquisition rate, monthly maximium, minimum and mean wave heights, frequency of wave direction are summarized. Wave height and period scatter diagrams and n-year return period wave heights are estimated. Wave periods of maximum wave heights are also estimated.

• Journal of Fisheries and Marine Sciences Education
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• v.27 no.5
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• pp.1303-1309
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• 2015

The behavior and flow characteristics of the floating wave energy converter were analyzed by using CFD in this study. The average significant wave height was confirmed as 0.5~2.0m from the Korean coastal sea area. This study was carried out by selecting a range of 1.0~1.6m in the wave height to simulate the operations of realistic wave energy converter system. The principle of a piston wave maker was applied in order to produce periodic wave. The behavior of the wave energy converter and the state of the wave overtopping according to the generated periodic wave were confirmed through the unsteady three-dimensional flow analysis. It was found that the wave overtopping rate according to the generated periodic wave was in range of the 11.6~30.0 kg/s.

• 한국신재생에너지학회:학술대회논문집
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• 2010.06a
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• pp.235.2-235.2
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• 2010

In this study, the wave power resources at the southern sea of Korea were estimated by using the hindcasted wave data of previous researches. The used data were wave heights, periods and directions which were hindcasted around the Korea peninsular from 1979 to 2003. The spatial resolution of the hindcasted data is $1/6^{\circ}$(about 18 km). In winter, the northwest monsoon increase the wave power, while the wave power around Korea peninsular is very small in spring. The maximum value of the annual mean wave power is about 13 kW/m at Gageo-do, Heuksan-do and western region of Jeju-do, while those at the southern sea of Korea is only 4 kW/m, which is relatively small. The wave power at Korean east sea is lower than that of Korean southern sea. We obtained the wave resources information, in a fine grid, at Gageo-do, Heuksan-do, and western sea of Jeju-do, by solving SWAN model with the boundary conditions of hindcasted wave data.

• Journal of the Society of Naval Architects of Korea
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• v.58 no.6
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• pp.339-347
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• 2021

Piston type wave makers or flap type wave makers are usually adopted as a wave maker which disturbing the fluid domain with sinusoidal motion. Recently hybrid wave maker which could be operated as not only piston type and/or flap type but also swing type wave maker have been devised by utilizing the link mechanism. The wave board of hybrid wave maker has been devised to be independently controlled by the horizontal actuators on upper and lower end of the wave board. The wave board could operate as a flap type wave board when the lower hinge is in a stationary condition and the upper hinge is operated with sinusoidal motion. On the contrary, the swing type wave board could be obtained by the lower hinge is activated and the upper hinge is in a stationary condition. When both end of the wave board is activated in a synchronized condition, the wave board motion become piston motion. In addition the hybrid wave maker could enhance the piston motion with flap motion or swing motion by selecting control parameters. Various wave board motion of hybrid wave maker and relevant wave form have measured on the wave board and departed location. It is appeared that the novel hybrid wave maker could be utilized for the improvement of wave qualities in experiments.

• Journal of Navigation and Port Research
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• v.31 no.7
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• pp.579-587
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• 2007

Samchunpo(Sin Hyang) Harbor is located in the bay of Sa Chun, the central south coast of Korean peninsula. The harbor and coastal boundaries have been protecting by natural coastal islands and shoals. Currently, The Sin Hyang harbor needs maintenance and renovation of the sheltered structures against the weather deterioration and typhoon damages. Consequently to support this, the calculation of accurate design wave through the typhoon wave attack is necessary. In this study, calculation of incident wave condition is simulated using steady state spectrum energy wave model(wide area wave model) from 50 years return wave condition. And this simulation results in wide offshore area were used for the input of the extended mild slope wave model at the narrow coastal area. Finally, the calculation of design wave at Sin Hyang harbor entrance was induced by Boussinesq wave model(detail area wave model) simulation. The numerical model system was able to simulate wave transformations from generation scale to shoreline or harbor impact. We hope these results will be helpful to the engineers doing placement, design, orientation, and evaluation of a wide range of potential solutions in this area.

• Journal of Coastal Disaster Prevention
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• v.4 no.4
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• pp.189-196
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• 2017

Ocean Research Stations (ORSs) is the ocean platform type observation towers and measured oceanic, atmospheric and environmental data. These station located on the offshore area far from the coast, so they can produce the data without land effect. This study focused to improve the wave data quality of ORS station. The wave observations at ORSs are used by the C-band (5.8 GHz, 5.17 cm) MIROS Wave and Current Radar (MWR). MWR is convenient to maintenance and produce reliability wave data under bad weather conditions. MWR measured significant wave height, peak wave period, peak wave direction and 2D wave spectrum, so it's can provide wave information for researchers and engineers. In order to improve the reliability of MWR wave data, Datawell Waverider Buoy was installed near the one ORS (Socheoncho station) during 7 months and validate the wave data of MWR. This study found that the wave radar tend to be overestimate the low wave height under wind condition. Firstly, this study carried out the wave Quality Control (QC) using wind data, however the quality of wave data was limited. So, this study applied the four filters (Correlation Check, Direction Filter, Reduce White Noise and Phillips Check) of MWR operating software and find that the filters effectively improve the wave data quality. After applying 3 effective filters in combination, the RMSE of significant wave height decreased from 0.81m to 0.23m, by 0.58m and Correlation increased from 0.66 to 0.96, by 0.32, so the reliability of MWR significant wave height was significantly improved.

• Journal of Koreanology Reviews
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• v.1 no.1
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• pp.31-36
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• 2022

Recently, as the status of South Korean popular culture has risen, the Korean Wave is gaining popularity not only in Asia but also in Europe, America, and South America, and is currently at the center of the global cultural phenomena. Among them, in particular, the cultural content industry has been developing rapidly thanks to the Korean Wave. Currently, the Korean Wave is spreading all over the world while bringing about positive effects to South Korea. In fact, until 2017, political and social issues such as 'North Korea/North Korean nuclear weapons' and 'Korean War' were considered as the images associated with South Korea, but from 2018, it has been shown that all images associated with South Korea are cultural content except for 'IT industry'. Given the economic effects that can be obtained not only from the positive associated images of South Korea per se but also from the complex action with various industries in South Korea, the craze for the Korean Wave can be viewed as affecting the overall national prestige of South Korea. For the steady vogue of the Korean Wave, thorough investigation of the Korean Wave and understanding of the expectations of consumers of the Korean Wave seem to be necessary

• Journal of Ocean Engineering and Technology
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• v.38 no.3
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• pp.103-114
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• 2024

Remote sensing wave observation data are crucial when analyzing ocean waves, the main external force of coastal disasters. Nevertheless, it has limitations in accuracy when used in low-wind environments. Therefore, this study collected the raw data from MIROS Wave and Current Radar (MWR) and wave radar at the Ieodo Ocean Research Station (IORS) and applied the optimal filter by combining filters provided by MIROS software. The data were validated by a comparison with South Jeju ocean buoy data. The results showed it maintained accuracy for significant wave height, but errors were observed in significant wave periods and extreme waves. Hence, this study used an artificial neural network (ANN) to improve these errors. The ANN was generalized by separating the data into training and test datasets through stratified sampling, and the optimal model structure was derived by adjusting the hyperparameters. The application of ANN effectively improved the accuracy in significant wave periods and high wave conditions. Consequently, this study reproduced past wave data by enhancing the reliability of the MWR, contributing to understanding wave generation and propagation in storm conditions, and improving the accuracy of wave prediction. On the other hand, errors persisted under high wave conditions because of wave shadow effects, necessitating more data collection and future research.