• International Journal of Naval Architecture and Ocean Engineering
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• v.2 no.1
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• pp.34-38
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• 2010

Field investigations have been carried out in two 60-day stages on the surf beat low frequency waves in Anzali port, one of the main commercial ports in Iran, located in southwest coast of the Caspian Sea. The characteristics of significant water waves were measured at three metering stations in the sea, one at the entrance of the port and three in the basin. The measured data were inspected to investigate the surf beat negative effects on the tranquility of the port. Using field measurements and complementary numerical modeling, the response of the basin to the infra-gravity long waves was inspected for a range of wave frequencies. It was concluded that the water surface fluctuations in the port is strongly related to the incident wave period. The long waves with periods of about 45s were recognized as the worst cases for water surfaceperturbation in the port. For wave periods higher than the mentioned range, the order of fluctuation was generally low.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.3 no.2
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• pp.100-107
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• 1991

The purposes of this study are 1) to observe the wave-induced liquefaction in the oceanic seabed. 2) to verify the liquefaction theory proposed by the Authors. The study consists of the field observation and theoretical analysis on the wave-induced liquefaction. In the field observation. The sea bottom pressures. the fluctuating pore pressures and stresses in the seabed and the changes of the water depth were observed for two years. The liquefaction theory proposed by the Authors is verified by the comparing the calculated fluctuating pore pressures with those observed in the field.

• Journal of the Korean Society of Hazard Mitigation
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• v.7 no.4
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• pp.97-105
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• 2007

This study has been focus to certify the run-up heights, losses of human lives and property damages due to the 1983 Central East Sea tsunami. We have conducted the interview with indigenous inhabitant and field surveying at the Imwon port, East sea in Korea in order to inquire into the state of things occurred during that period. It is also investigated how much well they are aware of the emergency action plan including the evacuation system. Base on the reliable interviews, we selected and surveyed 10 places at the Imwon port, where the historical maximum overflowing occurred due to the 1983 Central East Sea tsunami. The measured run-up heights are approximately $3.3m{\sim}4.0m$ at the selected 10 places and it is found that the sea water ran over the banks in Imwon stream about 700m upstream from the Imwon port. From this study we can suggest supplementing the present emergency action plan and supply the state-of-the-art inundation map.

• Journal of Environmental Science International
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• v.15 no.10
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• pp.919-928
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• 2006

The present study applied an atmospheric flow field model in Gwangyang-Bay which can predict local sea/land breezes formed in a complex terrain lot the development of a model that can predict short term concentration of air pollution. Estimated values from the conduct of the atmospheric flow field were used to evaluate and compare with observation data of the meteorological stations in Yeosu and the Yeosu airport, and the effect of micrometeorology of surround region by the coastal area reclamation was predicted by using the estimated values, Simulation results, a nighttime is appeared plainly land breezes of the Gwangyang-bay direction according to a mountain wind that formed in the Mt. of Baekwooun, Mt. of Youngchui. Land winds is formed clockwise circulation in the north, clockwise reverse direction in the south with Gangyang-bay as the center. Compared with model and observation value, Temperature is tend to appeared some highly simulation value in the night, observation value in the daytime in two sites all, but it is veil accorded generally, the pattern of one period can know very the similarity. And also, wind speed and wind direction is some appeared the error of observation value and calculation results in crossing time of the land wind and sea land, it can see that reproducibility is generally good, is very appeared the change land wind in the nighttime, the change of sea wind in the daytime. And also, according to change of the utilization coefficient of soil before and after development with Gwangyang-Bay area as the center. Temperature after development was high $0.55\sim0.67^{\circ}C$ in the 14 hoots, also was tend to appear lowly $0.10\sim0.22^{\circ}C$ in the 02 hours, the change of u, v component is comparatively tend to reduced sea wind and land wind, it is affected ascending air current and frictional power of the earth surface according to inequality heating of the generation of earth surface.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.17 no.4
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• pp.225-242
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• 2012

This is the first attempt to produce simultaneous surface current field from satellite altimeter data for the entire East Sea and to provide surface current information to users with formal description. It is possible to estimate surface geostrophic current field in near real-time because satellite altimeters and coastal tide gauges supply sea level data for the whole East Sea. Strength and location of the major currents and meso-scale eddies can be identified from the estimated surface geostrophic current field. The mean locations of major surface currents were explicated relative to topographic, ocean-surface and undersea features with schematic representation of surface circulation. In order to demonstrate the practical use of this surface current information, exemplary descriptions of annual, seasonal and monthly mean surface geostrophic current distributions were presented. In order to objectively classify surface circulation patterns in the East Sea, empirical orthogonal function (EOF) analysis was performed on the estimated 16-year (1993-2008) surface current data. The first mode was associated with intensification or weakening of the East Korea Warm Current (EKWC) flowing northward along the east coast of Korea and of the anti-cyclonic circulation southwest of Yamato Basin. The second mode was associated with meandering paths of the EKWC in the southern East Sea with wavelength of 300 km. The first and second modes had inter-annual variations. The East Sea surface circulation was classified as inertial boundary current pattern, Tsushima Warm Current pattern, meandering pattern, and Offshore Branch pattern by the time coefficient of the first two EOF modes.

• Journal of the Korean Society of Earth Science Education
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• v.13 no.1
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• pp.110-120
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• 2020

It is generally reported that field learning and a class using regional materials motivate learning and give a positive effect on learning of geology unit, science subject. The purpose of this study is to develop and to suggest regional materials for learning of geology unit, science subject at Jaeundo. The results of this study are as follows. Regional materials were developed at three locations (namjin dockyard area, yangsan beach area and dunjang beach area) of the study area. Namjin dockyard area (A site) is composed of terrain of sea cliff, sand beach and mud flat. Sedimentary rocks, weathering phenomenon of rocks and strata of various shape are distributed in sea cliff of A site. Yangsan beach area (B site) is composed of coastal terrain as sea cliff and sand beach about 1.5km long. Sedimentary rocks and rhyolite are distributed in sea cliff of B site. Tafoni formed by weathering process of rocks are developed on sedimentary rock outcrop of B site. Dunjang beach area (C site) is composed of coastal terrain of sea cliff, sand beach about 2km long and sea stack. Stratified sedimentary rocks are distributed in sea cliff of C site. Sea stack located in near halmi island on the west side of dunjang beach area is a good sample showing erosion process of sea cave for a long time. Unique geomorphology and geology phenomena distributed in 3 sites at Jaeundo can be used as regional materials for learning of geology unit, science subject. And, Regional materials shall be used in conjunction with the text book data of geology units. These 3 sites of the study area are worth using as field learning course for elementary and middle school students.

• Resources Recycling
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• v.26 no.2
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• pp.66-70
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• 2017

The purpose of this research was to estimate density changes of sea sand by washing. To examine water content test, field density test, particle density test and measuring of dump regarding extracted sea sand and selling one. Measured result of mean particle density of barge and dump were $2.666g/cm^3$, $2.651g/cm^3$, respectively. Also, measured result of field density for each sea sand was $1.716g/cm^3$, $1.331g/cm^3$ on average. Converted to the volume of 1ton of each sea sand, $0.583m^3$, $0.751m^3$, respectively. Occurring to volume change approximately 28.8% on average. The mean field densities of measuring of sea sand that dump and barge were $1.398g/cm^3$ and $1.716g/cm^3$ respectively. This values indicated $0.715m^3$ and $0.583m^3$ each, when converted to the volume of sea sand 1ton. It was found that the average of 22.6% volume change occurred between the amount of sea sand and the sales volume.

• Ocean and Polar Research
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• v.25 no.4
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• pp.437-446
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• 2003

Field measurements of directional waves were carried out during the summer of 2002 at two coastal sites in water of finite depth. A couple of general purpose instruments were used employing acoustic Doppler technology. The aim of the study was to investigate the spatial behavior of the directional movement of waves as they come ashore. In total,74 tests were carried out during which sea states of low to moderate intensity were recorded. A great number of these runs displayed bimodal characteristics of the spreading function at high frequencies. It was found that in general, the frequency-integrated directional width tends to broaden as the water shoals and when refraction effects are negligible. This is attributed to wave-wave interactions that become pronounced in shallow water. The same directional width showed, also, a tendency to increase with increasing peak frequency of the sea state spectrum. The behavior of the kurtosis of the spreading function was also examined. It was found that for higher frequencies this index tends to increase in wave spectra above a certain sea severity threshold.

• Water for future
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• v.16 no.4
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• pp.221-236
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• 1983

In semi-enclosed shallow sea areas typified by the Yellow sea and the East China Sea, currents and sea surface variations are predominantly tidal. During the recent years two-dimensional numerical hydrodynamic model of the Yellow Sea and the East China Sea has been developed, based on the vertically-integrated equations of motion and continuity, capable of reproducing amplitudes and phases of the principal components of tides to satisfiable accuracy. As a subsequent development a three-dimensional hydrodynamical nymerical model covering the Yellow Sea and the East China Sea has been formulated to investigate the vertical distribution of horizontal tidal current and the response of the continented to investigate the vertical distribution of horizontal tidal current and the response of the continental shelf sea to steady uniform wind stress field imposed over the surface. Features of the M2 tidal current and the wind-induced three-dimensional current structure determined from the computation have been examined and discussed.

• Ocean and Polar Research
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• v.25 no.3
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• pp.287-302
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• 2003

The seasonal variations in the circulation of the water mass in the East Sea/Japan Sea have been simulated using a free surface primitive ocean model, RIAMOM (RIAM Ocean Model), comparing the results from GFDL-MOM1 (Geophysical Fluid Dynamics Laboratory Modular Ocean Model, version 1.1, hereafter MOM) with the GDEM (Generalized Digital Environmental Model) data. Both models appear to successfully reproduce the distinct features of circulation in the East Sea/Japan Sea, such as the NB (Nearshore Branch) flowing along the Japanese coast, the EKWC (East Korean Warm Current) flowing northward along the Korean coast, and the NKCC/LCC (North Korean Cold Current/Liman Cold Current) flowing southwestward along Korean/Russian coast. RIAMOM has shown better performance, compared to MOM, in terms of the realistic simulation of the flow field in the East Sea/Japan Sea; RIAMOM has produced more rectified flows on the coastal region, for example, the narrower and stronger NKCC/LCC than MOM has. There is however obvious differences between the model results and the GDEM data in terms of the calculation of the water mass; both models have shown a tendency to overpredict temperature and underpredict salinity below 50m; more diffusive forms of thermocline and halocline have been simulated than noted in GDEM data.