• Journal of Environmental Science International
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• v.15 no.8
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• pp.727-735
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• 2006

In this study, the PHYTO-PAM-fluorometric method was used to evaluate the ETR$_{max}$ in terms of sensitivity to DIN/DIP against 14 microalgae: Prorocentrum micans, Heterocapsa triquetra, Gymnodinium impudicum, Cymnodinium catenatum, Amphidinium caterae, Chlorella vulgaris, Chroococcus minutus, Microcystis aeruginosa, Chlorella ellipsoidea, Nannochloris oculata, Oocystis lacustris, Chroomonas salina, Gloeocystis gigas, and Prymnessium parvum. We found that P. micans, H. triquetra, and A. caterae exposed to the maximum level of DIN/DIP were significantly smaller in the ETR$_{max}$ than that of the minimum and moderate mixture. Unlikely the ETR$_{max}$, the initial slope alpha was not significantly different at the level of 60 DIN/DIP. In G. catenatum, the moderate levels of 15 and 20 in DIN/DIP were found to be significantly different from the ETR$_{max}$ at Chl-Ch4. Gymnodinium impudicum had a higher value than that of the ETR$_{max}$ than that of dinoflagellates used in this study, ranging from 306.1 (Ch4, DIN/DIP: 10) to 520.1 (Ch4, DIN/DIP: 30). The ETR$_{max}$ value obtained from other microalgae was similar to C. impudicum at any of the ratios of DIN/DIP and channels. Consequently, the influence of offshore water current assures us of the suppression of photosynthesis and electron transport rate in dinoflagellates. Gymnodinium impudicum has not been researched in the area of red tides in Korea, but it will be enough to creat the massive algal blooms in the future because of higher potential photochemical availability.

• Ocean and Polar Research
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• v.39 no.1
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• pp.23-34
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• 2017

This study was carried out to investigate the spatial distributions of the macrobenthic communities in the Seomjin River estuary from May, 2015 to May, 2016. The number of species was 163, the mean density was $1,865ind.m^{-2}$, biomass was $204g{\cdot}wet\;m^{-2}$ during this study period. The highest number of species and density appeared among polychaetes whereas the most biomass was contributed by mollusks due to the presence of Corbicula japonica in every season. The study area was divided into 3 regions with similar benthic fauna responding to the gradient of the salinity. Praxillella praetermissa was the dominant species in regions of over 30 psu during all seasons. C. japonica and Hediste diadroma were dominant in the upper regions of the Seomjin River where the salinity was less than 10 psu. Heteromastus filiformis showed the broadest distributional range and dominated in all seasons except for the most upper stream at st. 7. From the result of the Bio-Env analysis, salinity was the most important environmental factor affecting the formation of macrobenthic communities in the study area, and salinity and TOC were the highest contributors to the macrobenthic communities. From the correlation analysis between major dominant species and environmental factors, C. japonica, Prionospio japonica and H. diadroma showed a negative correlation with salinity, while P. praetermissa and Scolectoma longifolia showed a positive correlation. H. filiformis was little affected by salinity but showed a positive correlation with TOC or silt content of sediment.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.22 no.1
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• pp.36-41
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• 2012

We have been performed on $Co^{60}$ ${\gamma}$-ray irradiation of South Sea cultured pearls, with the absorbed dose of 0.1~100 kGy at room temperature. In addition, it was investigated electron paramagnetic resonance (EPR) and amino acid analysis (AAA) for detection of Gamma irradiated South Sea cultured pearls. It was observed that the irradiated South Sea cultured pearls revealed additional free radical peak such as $CO_2^-$, at a g-factor of $2.001{\pm}0.002$ in EPR spectra. From the amino acid analysis (AAA), it was shown that some of amino acid in the protein of the nacre destroyed after ${\gamma}$-ray; glutamic acid residue by 11.43 %, alanine by 3.11 %, and histidine by 43.75 %. It was useful to detect the irradiated South Sea cultured pearls by EPR measurement in our study.

• Strategy21
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• s.40
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• pp.131-143
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• 2016

On 12 July 2016, China's maritime claim to most of the South China Sea (SCS) based on the so-called nine-dash line was rejected by the Arbitral Tribunal, constituted under Annex VII to the UN Convention on the Law of the Sea (UNCLOS) concerning issues in the South China Sea including the legality of the so-called "nine-dashed line", the status of certain maritime features and their corresponding maritime entitlements, together with the lawfulness of certain actions by China which the Philppines, in a case brought in 2013, alleged were violations. As having the Tribunal determined that China's claim had no legal grounds in UNCLOS, thus undermining China's claims, and establishing that China has no exclusive legal rights to control the area roughly the size of India. There are some major implications from the Tribunal's ruling in the Arbitration award. These include implications on: how to delimit the maritime boundary in disputed waters, how to promote maritime confidence-building measures, how to safeguard maritime safety and security, and how to promote the rule of law in the SCS. Since its application of UNCLOS in East Asia, it has been obvious that the only way to resolve maritime disputes in the region is to build strong maritime cooperative partnerships under the auspices of the rule of law.

• Strategy21
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• s.31
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• pp.220-250
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• 2013

South Korean national security strategy should be developed to effectively handle and counter increasing maritime threats and challenges. There are three major maritime threats South Korea faces today; maritime disputes on the EEZ boundary and Dokdo islet issues, North Korean threats, and international maritime security. Maritime disputes in the region are getting intensified and turned into a military confrontation after 2010. Now regional countries confront each other with military and police forces and use economic leverage to coerce the others. They are very eager to create advantageous de facto situations to legitimize their territorial claims. North Korean threat is also increasing in the sea as we witnessed in the Cheonan incident and Yeonpyoung shelling in 2010. North Korea resorts to local provocations and nuclear threats to coerce South Korea in which it may enjoy asymmetric advantages. The NLL area of the west sea would be a main hot spot that North Korea may continue to make a local provocation. Also, South Korean national economy is heavily dependent upon foreign trade and national strategic resources such as oil are all imported. Without an assurance on the safety of sea routes, these economic activities cannot be maintained and expanded. This paper argues that South Korea should make national maritime strategy and enhance the strength of naval forces. As a middle power, its national security strategy needs to consider all the threats and challenges not only from North Korea but also to maritime security. This is not a matter of choice but a mandate for national survival and prosperity. This paper discusses the importance of maritime security, changing characteristics of maritime threats and challenges, regional maritime disputes and its threat to South Korea's security, and South Korea's future security strategy and ways to enhance the role of naval forces. Our national maritime strategy needs to show middle and long term policy directions on how we will protect our maritime interests. Especially, it is important to build proper naval might to carry out all the roles and missions required to the military.

• Environmental Analysis Health and Toxicology
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• v.12 no.3_4
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• pp.67-73
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• 1997

This study was carried out to investigate the contents of heavy metals such as iron, copper, lead, cadmium, magnesium, platium in connection with water pollution in sea weed (dried laver) collected from the west, south, south- west, and east coasts of Korea. The results of the study are as follows; Iron was shown the highest value (1.280ppm) in the wild laver from the south coast. Copper was detected in larger qauntities (0.169 ppm) in green laver than in any other kinds of laver observed in this study. Lead was detected in larger quantities (0.195ppm) in the usual laver and green laver from the south-west coast as compared with the other coasts. Although cadmium and platium was also detected from every kind of laver, the concentrations were not over the allowance of the residual.

• Animal cells and systems
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• v.1 no.4
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• pp.543-563
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• 1997

One new copepod species (Doropygus hoi n. sp.) is described based on specimens taken from solitary ascidians collected from the East Sea (Sea of Japan) and the South Sea. Doropygus pinguis Ooishi, 1962 taken from solitary ascidians, Styela plicata (Lesueur) and Boltenia echinata (Linnaeus), collected from 8 localities of the South Sea and the East Sea are redescribed.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.53 no.1
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• pp.98-102
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• 2020

We examined the comparative spawning ecology of daggertooth pike conger Mureanesox cinereus and common pike conger M. bagio in the South Sea of Korea from May 2018 to December 2019. In the South Sea of Korea, the mean total length (TL) of M. cinereus was significantly smaller than that of M. bagio. The sex ratios of both species were skewed toward females. The spawning period of M. cinereus was from June to October, while the spawning period of M. bagio was from August to October. The lengths at 50%, 75%, and 97.5% sexual maturity of M. cinereus females were estimated as 54.6 cm, 60.4 cm, and 74.1 cm TL, respectively. It was not possible to estimate lengths at sexual maturity for M. bagio in the South Sea of Korea due to the absence of immature stages.

• Atmosphere
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• v.19 no.1
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• pp.67-78
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• 2009

A strong negative correlation has been detected between the North Pacific Oscillation Index (NPI) and the Effective Drought Index (EDI) in May over Korea. In May of positive NPI year, anomalous patterns caused a drought in Korea as follows: the anomalous south-low, north-high low-level pressure patterns in the northeast and southeast of Korea have strengthened the anomalous northerlies to Korea. In addition, these anomalous northerlies have prevented western North Pacific (WNP) high from moving northward. As a result, anomalous descending flows have strengthened in the mid-latitude region in East Asia. In the WNP, the anomalous south-high, north-low sea surface temperature (SST) has been widely distributed, which has strengthened anomalous south-low, north-high low-level pressure patterns. These anomalous characteristics of pressure and SST patterns observed in May of positive NPI years have already been detected in previous winter (December-February) and early spring (March, April). In addition, the anomalous negative sea ice concentration in the North Pacific during two seasons has strengthened the anomalous anticyclonic circulation in the same region and in turn made a contribution to formation of anomalous south-low, north-high pressure patterns in May.

• Atmosphere
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• v.21 no.4
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• pp.439-446
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• 2011

NCEP reanalysis data were analyzed in order to provide distribution of global wind resource and wind speed in the surface layer for the years 2000-2009. Wind speed at 10 m above ground level (AGL) was converted to wind speed at 80 m above the ground level using the power law. The global average 80 m wind speed shows a maximum value of $13ms^{-1}$ at the storm track region. High wind speed over the land exists in Tibet, Mongolia, Central North America, South Africa, Australia, and Argentina. Wind speed over the ocean increased with a large value in the South China Sea, Southeast Asia, East Sea of the Korea. Sea surface wind in Western Europe and Scandinavia are suitable for wind farm with a value of $7-8ms^{-1}$. Areas with great potential for wind farm are also found in Eastern and Western coastal region of North America. Sea surface wind in Southern Hemisphere shows larger values in the high latitude of South America, South Africa and Australia. The distribution of low-resolution reanalysis data represents general potential areas for wind power and can be used to provide information for high-resolution wind resource mapping.