• Journal of Ocean Engineering and Technology
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• v.27 no.4
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• pp.68-75
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• 2013

This paper investigates the characteristics of waves generated by a flap-type wave maker in a two-dimensional wave channel. Measurements are carried out for various water depths, wave heights, periods, and lengths capacitance-type wave height gages. The experimental results are shown to satisfy the dispersion relation of the linear wave theory. For waves with a small height and long period, the wave profiles agree well with those of the linear wave theory. However, as the wave height and period become higher and shorter, respectively, it is shown that the wave profiles measured in the present experiments are different from the linear wave profiles, and the measured wave heights are smaller than the target wave heights, which may be due to the non-linearity of the waves. As the wave progresses toward the channel end, the wave height gradually decreases. This reduction in the wave height along the wave channel is explained by the wave energy dissipation due to the friction of the side walls of the channel. The performance of the wave absorber in the channel is found to be acceptable from the results of the wave reflection tests.

• Water for future
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• v.17 no.2
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• pp.113-124
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• 1984

The equations for the wave orthogonals and wave heights are presented along the depth using time as the independent variable, The effect of wave refracion is included. In this paper, a numerical procedure is described for the calculation and two analytical solutions are presneted in case of straight and parallel bottom contours and horizontal bottom in order to check the computed results. The computer outputs are in the form of automatically plotted wave orthogonals and wave heights along the wave path. In practical calculation of wave heights, Samchuckk Pohang, and Hanlim are selected as plane sloping bottoms.

• Journal of Korea Water Resources Association
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• v.32 no.6
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• pp.649-655
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• 1999

The maximum run-up heights of periodic waves are numerically investigated in this study. Incident waves are sinusoidal and enoidal waves. The maximum run-up height of enoidal wave approaches that of sinusoidal wave as the wave length decreases, while it approaches that of solitary wave as the wave length increases. If wave height is fixed, the maximum run up heights of enoidal waves are always greater than those of sinusoidal waves but smaller than those of solitary waves.

• Journal of Ocean Engineering and Technology
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• v.17 no.5 s.54
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• pp.25-31
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• 2003

Numerical experiments have been conducted using the nonlinear combined refraction-diffraction model, in order to analyze the generation characteristics of stem wave, which is formed by the interaction between vertical structure and the oblique incident waves. The results of stem wave are discussed through the stem wave height distribution along/normal vertical structure, under the wide range of incident wave conditions-wave heights, periods, depths, and angles. Under the same wave height and period, the larger the incident wave angle, the higher the stem wave heights. According to the results of wave height distribution, in front of vertical structure, the maximum of stern wave heights occurs in the location bordering the vertical wall. Furthermore, the most significant result is that stem waves occur under the incident angles between $0^{\circ}\;and\;30^{\circ}$, and the stem wave height ratio has the maximum value, which is approximately 1.85 times the incident wave height when the incident wave angle becomes $23^{\circ}$.

• Journal of the Korean Society of Hazard Mitigation
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• v.9 no.3
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• pp.135-142
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• 2009

The initial free surface profile and energy of a tsunami are closely related to the wave heights of a tsunami in nearshore and can be determined by using the earthquake parameters. Along the Western coast of Japan, the possibility of a tsunami triggering by undersea earthquakes is very high. Many seismologists have attempted to predict the parameters of earthquakes that could occur in these regions, but it is difficult to accurately predict them. As such, several case studies have been conducted involving behaviors of an unexpected tsunami that occurred in this region. If a relationship between the earthquake parameters and the wave heights of a tsunami is found, it would be easier to examine the effects of the tsunami. In this study, several virtual tsunami events have been simulated, and the wave heights of the tsunami are computed by varying the earthquake parameters to examine the relationship between the earthquake parameters and the tsunami wave heights. Numerical simulations have been conducted in virtual topography.

• Journal of the Korean Society for Marine Environment & Energy
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• v.7 no.1
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• pp.47-55
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• 2004

In this paper, The statistical properties of ocean waves in the sea area of Hong-do, Korea are examined based on 1998-2002's wave data from a directional wave buoy. Wave data aquisition rate, 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. Large amplitude wave characteristics during the typhoon Prapiroon in 2000, Rusa in 2002 are also examined.

• Journal of Environmental Science International
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• v.24 no.3
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• pp.291-302
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• 2015

The seasonal variations of sea surface winds and significant wave heights were investigated using the data observed from the marine meteorological buoys (nine stations) and Automatic Weather Stations (AWSs) in lighthouse (nine stations) around the Korean Peninsula during 2010~2012. In summer, the prevailing sea surface winds over the East/West Sea and the South Sea were northerly/southerly and easterly/westerly winds due to both of southeast monsoon and the shape of Korean Peninsula. On the other hand, the strong northerly winds has been observed at most stations near Korean marginal seas under northwest monsoon in winter. However, the sea surface winds at some stations (e.g. Galmaeyeo, Haesuseo in the West Sea) have different characteristics due to topographic effects such as island or coastal line. The significant wave heights are the highest in winter and the lowest in summer at most stations. In case of some lighthouse AWSs surrounded by islands (e.g. Haesuseo, Seosudo) or close to coast (e.g. Gangan, Jigwido), very low significant wave heights (below 0.5 m) with low correlations between sea surface wind speeds and significant wave heights were observed.

• Proceedings of the Korea Committee for Ocean Resources and Engineering Conference
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• 2001.10a
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• pp.117-121
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• 2001

For the effective development or preservation of Tokdo, the natural environments in the ambient sea area should be well investigated. The wave deformations and wave breaking in the vicinity have much affected the bottom morphology of Tokdo as well as its ecological environment. The present study investigates the wave deformations and wave breaking through a numerical model. The final goal is to provide the fundamental wave data for the effective development or preservation of Tokdo in future. The extended mild slope equation was applied to Tokdo sea area for three different deep water wave conditions (S, SSE, NNE directions). The results showed that for the S and SSE directions the wave heights in the area between the east island and the west island were very low with the level of 1~2m, but for the NNE direction they appeared pretty high with 3~4m, In the sea area near the northwest of west island, the wave heights were low to be 1~3m for all three directions of deep water wave.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.16 no.3
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• pp.130-141
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• 2004

For a coastal or harbor structure design, one of the most important environmental factors is the appropriate design wave condition. Especially, the information of deepwater wave height distribution is essential for reliability design. In this paper, a set of deep water wave data obtained from KORDI(2003) were analyzed for extreme wave heights. These wave data at 67 stations off the Korean coast from 1979 to 1998 were arranged in the 16 directions. The probability distributions considered in this research were the Weibull, the Gumbel, the Log-pearson Type-III, and Lognormal distribution. For each of these distributions, three parameter estimation methods, i.e. the method of moments, maximum likelihood and probability weighted moments, were applied. Chi-square and Kolmogorov-Smirnov goodness-of-fit tests were performed, and the assumed distribution was accepted at the confidence level 95%. Gumbel distribution which best fits to the 67 station was selected as the most probable parent distribution, and optimally estimated parameters and 50 year design wave heights were presented.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.19 no.4
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• pp.329-335
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• 2007

The eye measurement to observe the sea surface condition and estimate the wave height has been used in the open sea or the ship. The experts in the eye estimation can measure the wave height very accurately. The Beaufort wind scale is most widely used as a standard index of the eye measurement. However, more definite reference data such as the representative images by each wave heights must be necessary because the appearances and explanations in the Beaufort wind scale are not enough to understand the sea surface condition far the researcher and the public. The modern field data acquisition technique has been developed to measure wave heights, ocean weather data and even images of the sea surface in real-time. In this study, the wireless field image transmitting system for wave heights and images is installed in the real-time ocean measurement system of Chodo light tower near Sokcho city in South Korea. The wave heights and surface images acquired from the real time system in the field are compared with explanations of the Beaufort wind scale. The wave heights and images measured with the precision ultrasonic wave sensor and the scientific sea surface image transmitting system should be helpful to obtain more precise and definite information than the data from the Beaufort wind scale.