• Korean Journal of Computational Design and Engineering
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• v.10 no.3
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• pp.162-167
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• 2005

A 3D solid element mesh generation algorithm was newly developed. 3D surface points of global rectangular coordinates were supplied by a 3D laser scanner. The algorithm is strait forward and simple but it generates hexahedral solid elements. Then, the surface rectangular elements were generated from the solid elements. The key of the algorithm is elimination of unnecessary elements and 3D boundary surface fitting using given 3D surface point data.

• Proceedings of the KSEEG Conference
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• 2007.04a
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• pp.434-435
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• 2007

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• Animal Systematics, Evolution and Diversity
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• v.12 no.4
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• pp.289-304
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• 1996

Notodelphyid copepods taken from Ascidians, Ascidia samea (Oka) and Ascidia sp. which had been collected in the East sea and the Korea Strait are reported. These copepods are Lonchidiopsis hartmeyeri Vanh ffen, 1917 and Pachypygus curvatus Ooishi 1961, and are redescribed as new records to the Korea fauna.

• Ocean Science Journal
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• v.40 no.3
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• pp.167-176
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• 2005

A time-series sediment trap was deployed at 1,034 m water depth in the eastern Bransfield Strait for a complete year from December 25, 1998 to December 24, 1999. About 99% of total mass flux was trapped during an austral summer, showing distinct seasonal variation. Biogenic particles (biogenic opal, particulate organic carbon, and calcium carbonate) account for about two thirds of annual total mass flux $(49.2\;g\;m^{-2})$, among which biogenic opal flux is the most dominant (42% of the total flux). A positive relationship (except January) between biogenic opal and total organic carbon fluxes suggests that these two variables were coupled, due to the surface-water production (mainly diatoms). The relatively low $\delta^{13}C$ values of settling particles result from effects on C-fixation processes at low temperature and the high $CO_2$ availability to phytoplankton. The correspondingly low $\delta^{l5}N$ values are due to intense and steady input of nitrates into surface waters, reflecting an unlikely nitrate isotope fractionation by degree of surface-water production. The $\delta^{l5}N$ and $\delta^{l3}C$ values of sinking particles increased from the beginning to the end of a presumed phytoplankton bloom, except for anomalous $\delta^{l5}N$ values. Krill and the zooplankton fecal pellets, the most important carriers of sinking particles, may have contributed gradually to the increasing $\delta^{l3}C$ values towards the unproductive period through the biomodification of the $\delta^{l3}C$ values in the food web, respiring preferentially and selectively $^{12}C$ atoms. Correspondingly, the increasing $\delta^{l5}N$ values in the intermediate-water trap are likely associated with a switch in source from diatom aggregates to some remains of zooplankton, because organic matter dominated by diatom may be more liable and prone to remineralization, leading to greater isotopic alteration. In particular, the tendency for abnormally high $\delta^{l5}N$ values in February seems to be enigmatic. A specific species dominancy during the production may be suggested as a possible and speculative reason.

• Korean Journal of Ichthyology
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• v.18 no.1
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• pp.36-44
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• 2006

The distribution patterns of anchovy eggs and larvae and environmental characteristics such as oceanographic conditions and meteorological factors in the eastern part of Jeju Strait, Korea from June to October 2003 were investigated. During the sampling periods, the anchovy spawned on the coastal area mainly and approximately 85% of total egg abundance occurred in only two months, from July to August, suggesting that the main spawning season of anchovies is considered in summer from July and August in the study area. Relatively high proportions of the anchovy larvae larger than 20 mm TL observed in the eastern part area. These facts suggest that anchovy larvae gradually moved out to the eastern part of study area. Most wind speeds were markedly reduced to below 10 m/s with the exception of a few days and the precipitation was concentrated (37%) from July to August when the anchovy eggs and larvae occurred abundantly. Results of correlation analysis showed that the anchovy egg abundance correlated with the increasing chlorophyll a and copepod biomass. It is considered that the plankton biomass in the sea area would have significant effects on the anchovy spawning. In addition, salinity variations also had significant effects on the abundance of anchovy larvae, with increasing water temperature.

• Ocean Science Journal
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• v.40 no.2
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• pp.67-78
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• 2005

Complex physical, chemical and biological interactions off the Korean coast created several striking patterns in the phytoplankton blooms, which became conspicuous during the measurements of ocean color from space. This study concentrated on analyzing the spatial and temporal aspects of phytoplankton chlorophyll variability in these areas using an integrated dataset from a Sea-viewing Wide Field-of-view Sensor (SeaWiFS), Advanced Very High Resolution (AVHRR) sensor, and Conductivity Temperature Depth (CTD) sensor. The results showed that chlorophyll concentrations were elevated in coastal and open ocean regions, with strong summer and fall blooms, which appeared to spread out in most of the enclosed bays and neighboring waters due to certain oceanographic processes. The chlorophyll concentration was observed to range between 3 and $54\;mg\;m^{-3}$ inside Jin-hae Bay and adjacent coastal bays and 0.5 and $8\;mg\;m^{-3}$ in the southeast sea offshore waters, this gradual decrease towards oceanic waters suggested physical transports of phytoplankton blooms from the shallow shelves to slope waters through the influence of the Tsushima Warm Current (TWC) along the Tsushima Strait. Horizontal distribution of potential temperature $(\theta)$ and salinity (S) of water off the southeastern coast exhibited cold and low saline surface water $(\theta and warm and high saline subsurface water $({\theta}>12^{\circ}C; S>34.4)$ at 75dBar, corroborating TWC intrusion along the Tsushima Strait. An eastward branch of this current was called the East Korean Warm Current (EKWC), tracked with the help of CTD data and satellite-derived sea surface temperature, which often influenced the dynamics of mesoscale anticyclonic eddy fields off the Korean east coast during the summer season. The process of such mesoscale anticyclonic eddy features might have produced interior upwelling that could have shoaled and steepened the nutricline, enhancing phytoplankton population by advection or diffusion of nutrients in the vicinity of Ulleungdo in the East Sea.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.49 no.2
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• pp.234-240
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• 2016

We examined the diffusion of contaminants released from the southern coast around Fukushima, Japan, during the passage of typhoons using a three-dimensional numerical model (POM) to track diffusing radioactivity (RA) released from the nuclear power plant at Fukushima following the accident caused by the giant tsunami event in March 2011. Radioactive contaminants released during the passage of typhoons may have significantly affected not only Japanese but also Korean coastal waters. The model domain covered most of the northwestern Pacific including marginal seas such as the East/Japan Sea and the Yellow Sea. Several numerical experiments were conducted case studies focusing on the westward diffusion from the southern coast of Japan of contaminants derived from the source site (Fukushima) according to various attributes of the typhoons, such as intensity, track, etc. The model produced the following results 1) significant amounts of contaminants were transported in a westward direction by easterly winds favorable for generating a coastal air stream along the southern Japanese coast, 2) the contaminants reached as far as Osaka Bay with the passage of typhoons, forced by a 5-day positive sinusoidal form with a (right-) northward track east of Fukushima, and 3) the range of contamination was significant, extending to the interior of the East/Japan Sea around the Tsugaru Strait. The model suggests that contaminants and/or radioactivity released from Fukushima with the passage of typhoons can affect Korean waters including the northeastern East/Japan Sea around the Tsugaru Strait, especially when the typhoon tracks are favorable for generating a westward coastal air stream along the southern Japanese coast.

• Journal of Korea Port Economic Association
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• v.27 no.1
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• pp.111-135
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• 2011

The purpose of this article is to understand the present situation of energy maritime logistics and to suggest a safe way for maritime transportation. In addition, this study is going to assess the risk of maritime transport of energy and propose alternatives in terms of strategy and policy. We examine the security of the Strait of Hormuz, near the east coast of Somalia, the Gulf of Aden and the Strait of Malacca where the Korean tankers pass through and discuss countermeasures responding to a variety of dangerous situations. This article also provides plans for stable supply of energy in case of Korea peninsula crisis and emphasizes the need of establishing cooperation with neighbor countries.

• Journal of the Korean earth science society
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• v.36 no.2
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• pp.190-197
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• 2015

This study investigated the paleoclimatic change using diatoms that were extracted from the high-resolution laminated layers of diatom ooze sediment cores GC08-EB01 in the eastern basin of the Bransfield Strait, Antarctica. The range of diatom valves per gram of dry sediment was from $0.4-4.2{\times}10^8g^{-1}$ in quantitative diatom assemblage analysis. Laminations are classified using visually dominant diatom species and terrigenous content. Biogenic diatom ooze laminae characterised by bloom of Corethron crilophilum, Eucampia antarctica, Fragilariopsis curta, F. kerguelensis, Odontella weissflogii, Proboscia inermis, R. styliformis, Thalassiosira antarctica, and Chaetoceros resting spores. Terrigenous laminae characterised by mixed diatom assemblage. The ratio of (Fragilariopsis curta+F. cylindrus)/Thalassiosira antarctica increase in horizons, suggesting increased sea-ice cover in the study area during the late Holocene (cold events). As a result, five cold events are identified on the basis of frequency of the critical taxa throughout the section.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.25 no.1
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• pp.1-14
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• 1992

With 16 years' oceanographic data(1973-1988) of the National Fisheries Research and Development Agency and the CTD data collected by a training ship of Korea Maritime University during Nov. 6-11, 1989, the inflow path of the bottom cold water in the western channel of the Korea Strait were investigated. Temperature of the bottom water in the western channel shows the lowest in summer and large annual variation. According to the temperature distributions in the years when the bottom cold water exists in the western channel in summer, the cold water in the southwestern region of the East Sea seems to intrude into the western channel through the sea southeast 10- 15 miles off Ulsan with its properties showing slight change during advection.