• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.22 no.4
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• pp.151-171
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• 2017

Most of oceanic current maps in the secondary school science and earth science textbooks have been made on the base of extensive in-situ measurements conducted by Japanese oceanographers during 1930s. According to up-to-date scientific knowledge on the currents in the Yellow Sea and the East China Sea (YES), such maps have significant errors and are likely to cause misconceptions to students, thus new schematic map of ocean currents is needed. The currents in the YES change seasonally due to relatively shallow water depths, complex terrain, winds, and tides. These factors make it difficult to construct a unified ocean current map of the YES. Sixteen major items, such as the flow of the Kuroshio Current into the East China Sea and its northward path, the origin of the Tsushima Warm Current and its path into the Korea Strait, the path of Taiwan Warm Current, the Jeju Warm Current, the runoff pattern of the Yangtze River flow, the routes of the northward Yellow Sea Warm Current, the Chinese Coastal Current, and the West Korea Coastal Current off the west coast of the Korean Peninsula, were selected to produce the schematic current map. Review of previous scientific researches, in-depth discussions through academic conferences, expert discussions, and consultations for three years since 2014 enabled us to produce the final ocean current maps for the YES after many revisions. Considering the complexity of the ocean currents, we made seven ocean current maps: two representative current patterns in summer and winter, seasonal current maps for upper layer and lower layer in summer and winter, and one representative surface current map. It is expected that the representative maps of the YES, connected to the current maps of the East Sea and the Northwest Pacific Ocean, would be widely utilized for diverse purposes in the secondary-school textbooks as well as high-level educational purposes and even for scientific scholarly experts.

• Korean Journal of Environmental Biology
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• v.31 no.1
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• pp.19-36
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• 2013

Physiochemical characters of sea waters during summer flood- and winter dry-seasons and their spatial variations were investigated along the coastal area off the eastern South Sea, Korea. Using the hierarchical clustering method, in this study, we present comprehensive analyses of coastal waters masses and their seasonal variations. The results revealed that the coastal water of the study area was classified into six water masses (A to F). During summer season, the surface water was mainly occupied by the coastal pseudo-estuarine water (water mass B) with low salinity and high nutrients and the river-dominated coastal water (water mass C) with low nutrients, respectively. The bottom water was dominated by cold water (water mass D) with very low temperature, high salinity and high nutrients, compared to masses of surface water. Notably, the water mass B, with high concentrations of nutrients (silicate and nitrogen) and low salinity, which is strongly controlled by the water quality of river freshwater, seems to play an important role in controlling the water quality and further regulating physical processes on ecosystem in the eastern coastal area of South Sea. The water mass D (bottom cold water) coupled with a strong thermocline, which exists in near-bottom layer along the western margin of Korea Strait, has a low temperature, pH and DO, but abundant nutrients. This water mass disappears in winter owing to strong vertical mixing, and subsequently may act as a pool for nutrients during winter dry-season. On the other hand, vertically well-mixed water column during the winter season was typically occupied by the Tsushima (water mass E) and the coastal water (water mass F) with a development of coastal front formed in a transition zone between them. These winter water masses were characterized by low nutrient concentration and balance in N/P ratio, compared with summer season with high nutrient concentrations and strong N-limitation. Accordingly, the analysis of water masses will help one to better chemical and biological processes in coastal area. In most of the study area, characteristically, the growth of phytoplankton community is limited by nitrogen, which is clearly different with coastal environment of West Sea of Korea, with a relative lack of phosphorus. It showed the western and the southern coasts in Korea are substantially different from each other in environmental and ecological characteristics.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.18 no.4
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• pp.234-265
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• 2013

Oceanic current maps in the secondary school science and earth science textbooks have played an important role in piquing students's inquisitiveness and interests in the ocean. Such maps can provide students with important opportunities to learn about oceanic currents relevant to abrupt climate change and global energy balance issues. Nevertheless, serious and diverse errors in these secondary school oceanic current maps have been discovered upon comparison with up-to-date scientific knowledge concerning oceanic currents. This study presents the fundamental methods and strategies for constructing such maps error-free, through the unification of the diverse current maps currently in the textbooks. In order to do so, we analyzed the maps found in 27 different textbooks and compared them with other up-to-date maps found in scientific journals, and developed a mapping technique for extracting digitalized quantitative information on warm and cold currents in the East Sea. We devised analysis items for the current visualization in relation to the branching features of the Tsushima Warm Current (TWC) in the Korea Strait. These analysis items include: its nearshore and offshore branches, the northern limit and distance from the coast of the East Korea Warm Current, outflow features of the TWC near the Tsugaru and Soya Straits and their returning currents, and flow patterns of the Liman Cold Current and the North Korea Cold Current. The first draft of the current map was constructed based upon the scientific knowledge and input of oceanographers based on oceanic in-situ measurements, and was corrected with the help of a questionnaire survey to the members of an oceanographic society. In addition, diverse comments have been collected from a special session of the 2013 spring meeting of the Korean Oceanographic Society to assist in the construction of an accurate current map of the East Sea which has been corrected repeatedly through in-depth discussions with oceanographers. Finally, we have obtained constructive comments and evaluations of the interim version of the current map from several well-known ocean current experts and incorporated their input to complete the map's final version. To avoid errors in the production of oceanic current maps in future textbooks, we provide the geolocation information (latitude and longitude) of the currents by digitalizing the map. This study is expected to be the first step towards the completion of an oceanographic current map suitable for secondary school textbooks, and to encourage oceanographers to take more interest in oceanic education.

• Journal of the Mineralogical Society of Korea
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• v.28 no.1
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• pp.71-81
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• 2015

This study was carried out in order to investigate the mineralogical characteristics of the core sediments (03GHP-02 and HB13-2), obtained from the Ulleung Basin and Hupo Basin, Korea. The results on mineral compositions, clay mineral compositions, and the total contents and sequential extraction of different fractions of the phosphorus in core samples showed that those values are different in two cores and also at different depths. In both samples, mineral compositions were the same, composed mainly of quartz, microcline, albite, calcite, opal A, pyrite, and clay minerals (illite, chlorite, kaolinite, and smectite). However, the sample from Hupo Basin contains more opal A. Both samples, especially the ones from Hupo Basin contains more smectite than those reported from East Sea, indicating the influence of paleo-Hwangwei River and the Tertiary Formation of Korea Peninsula. For the samples from Uleung Basin, at 0.7-3.5 m range in depth, the low content of opal A and the low illite crystallinity index can be inferred to indicate the relatively cool climate, corresponding to the ice age. Also, the content of total phosphorus was low in those samples. It was reported that East Sea at that time was isolated from the neighboring seas due to the decrease of the sea level, and as a result, the influx of sediments was supposed to be little through the strait and rivers. For the samples from Hupo Basin, there is no significant changes in clay mineral composition and the distribution of phosphorus with increasing depth. This little change can be interpreted to indicate that the sediments comprising the core might be deposited in a relatively short period of time or deposited in sedimentary environment in which there's no significant changes in sediment supplies. The values of crystallinity index of clay minerals are high in those samples, indicating that it was relatively warm during that time. Although the increase of fluctuation pattern can be observed, showing that the climate of this period often changed, it is supposed that it was generally warm.

• Ocean and Polar Research
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• v.32 no.3
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• pp.269-289
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• 2010

In Summer 2008, a multidisciplinary survey was conducted onboard R/V Haeyang 2000 to understand plankton response to the three distinct physico-chemical settings that developed in the Ulleung Basin of the East Sea. Baseline settings of hydrographic conditions included the presence of the thin (<20 m) Tsushima Surface Water (TSW) on top of the Tsushima Middle Water (TMW). It extends from the Korea Strait to $37^{\circ}N$ along the $130^{\circ}E$ and then turns offshore and encompasses the relatively saline (T>$26^{\circ}C$, S>33.7) Ulleung Warm Eddy surface water centered at $36.5^{\circ}N$ and $131^{\circ}E$. A relatively colder and saline water mass appeared off the southeastern coast of Korea. It was accompanied by higher nutrient and chlorophyll-a concentrations, suggesting a coastal upwelling. Most of the offshore surface waters support low phytoplankton biomass (0.3 mg chl-a $m^{-3}$). A much denser phytoplankton biomass (1-2.3 mg $m^{-3}$) accumulated at the subsurface layer between 20-50 m depth. The subsurface chlorophyll-a maximum (SCM) layer was closely related to the nutricline, suggesting an active growth of phytoplankton at depth. The SCM developed at shallow depth (20-30 m) near the coast and deepened offshore (50-60 m). A fucoxanthin/zeaxanthin ratio was high in coastal waters while it was low in offshore waters, which indicated that diatoms dominate coastal waters while cyanobacteria dominate offshore waters. The community structure and biomass of phytoplanktonare closely related to nitrogen availability. Zooplankton biomass was higher in the coastal region than in the offshore region while species richness showed an opposite trend. Zooplankton community structure retained a coastal/offshore contrast. These suggest that summer hydrography is a stable structure, lasting long enough to allow a hydrography-specific plankton community to evolve.

• Journal of Hospice and Palliative Care
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• v.10 no.3
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• pp.145-153
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• 2007

Purpose: This study was to analyze the research trend centering on the theses to hospice released in Korea. Methods: The researcher collected the academic degrees and theses published on the book of the academic society from 1991 to 2004, and examined 110 domestic papers of hospice. Results: 1) The number of articles increased 3 years after 1997, 52 (47%) theses were published in $2000{\sim}2002$. 97 (88%) articles were quantitative studies, and 13 (12%) were qualitative studies. 2) As for the subject, the results were: patients with end stage 44 (40%), nurse 18 (16%), hospice care system, facilities, and literature review 12 (10%). 3) As for main concepts of correlational studies 15 (13%), the results were: quality of life, activities of volunteers, suffering experience of nurse, and so on. 4) The subjects and contents of survey, the results were: pain control and need for nursing care in patients, need for spiritual and physical care in family, and so on. 5) The treatment of experimental research, the results were: hospice nursing, educational program, informational support, spiritual nursing, supportive nursing intervention, home hospice care, information services for control of cancer pain, and so on. 6) In the theme of the qualitative studies, the results were: experience of dying patients, perceive of hospice care and death, experience of family of terminal ill patients, meaning of dying in Korean. 7) In the instrument in studies, the results were: MQOL, EQOL, QOL, NIC, Need Scale, Spiritual Well-being Scale, Spiritual Perspective Scale, Coping for Grief Scale, K-CPAT, VAS, BPI, Depression Scale, Strait-anxiety Scale, Care-giver Burden Inventory, Burnout Inventory, Mental quality. Conclusion: More research needs to be encouraged in experimental and qualitative research fields. Researches should be conducted for the establishment of the basis of practical and theoretical framework and hospice polices.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.28 no.5
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• pp.677-697
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• 1995

The analysis of long- period sea level variations with tidal record data around Korea, Japan, and Russia shows that about half of the variations are due to atmospheric influences. The sea level variation by water movements is the largest in the coasts along the Tsushima Current, and becomes smaller in the distant areas. It suggests that the sea level varications are related with the Tsushima Current. The effect of sea level variations to ocean circulation has been studied with a numerical model allowing barotropic sea level fluctuations, like the result with GCM (Semtner) model by Pang et al.(1993), the present model also shows that waters basically flow along isobaths over the last China Sea after geostyophic adjustment around Taiwan. However, barotropic sea level fluctuation makes the basic circulation in the Yellow Sea, which waters flow into the central Yellow Sea and out along the west coast of the Korean Peninsula. Besides this, barotropic sea level fluctuation makes long period waves over the shelf area as the Kuroshio varies. By the waves, the basic circulation in the Yellow Sea is disturbed, so that the flow pattern of oppositely flowing into the Yellow Sea along the west roast of the Korean Peninsula appears. In the Yellow Sea circulation, it seems that northwest winds strengthen the basic circulat ion In winter, and southeast winds strengthen the disturbed circulation in summer. Another point appeared by the long period wave is that the Tsushima Current possibly originates in different areas. There have been two opposing argues on the area in which the Tsushima Current originates the southwest sea of Kyushu Island and the adjacent sea of Taiwan. Through this study, we found that both of them seem to be important areas for the origin of the Tsushima Current, and one of them is possibly strengthened by long period waves. The long period waves given by the variation of the Kuroshio Current in the adjacent sea of Taiwan propagate to the Korea Strait as forced waves. The wave continuously propagates to the last Sea through the eastern channel, but reflects in the western channel due to bottom topography. The reflected waves propagate southwestward along the last China Sea as free waves and determine the sea level variations with forced waves.

• 한국해양학회지
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• v.8 no.1
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• pp.33-45
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• 1973

Plankton samples used for the present study were collected by the NORPAC net during the CSK cruises in the Korean waters in March and August, 1967. Regional and seasonal variations in the zooplankton biomass (wet weight, mg/㎥) were noticed in the Korean waters. In March the highest biomass, 130mg/㎥ on the average, occurred in the southern part of Japan Sea, but the lowest biomass of less than 50mg/㎥ occurred in the Yellow Sea and the western sea of Cheju Island Contrally, in August, the average biomass of 120mg/㎥ was measured in the Yellow Sea, the western sea of Cheju Island and the coastal waters of southern Korea, while the biomass of Japan Sea was the lowest of the regions surveyed. In comparison with the zooplankton biomass, total number of zooplankton per cubic meter of water strained also showed regional and seasonal fluctuations. In general, variations in the number of zooplankton specimens follows the same trend as in the biomass. The largest number, up to 800mg/㎥ on the average, occurred in the southern part of Japan Sea in March and the lowest number, less than 200mg/㎥ occurred in the Yellow Sea and the western sea of Cheju Island. In August, as shown by the biomass fluctuations, the largest number of zooplankton 850mg/㎥ on the average occurred in the Yellow Sea, the western sea of Cheju Island and the coastal region of southern Korea. But the lowest number of less than 500mg/㎥ was found in the Japan Sea. Among the various groups of zooplankton examined, the following were dominant components of the zooplankton population: Copepoda, Chaetognatha, Siphonophora, Euphausiacea, Cladocera, Appendicularia, and Amphipoda. The zooplankton conposition was significantly differed between the Japan Sea and Yellow Sea. Copepods which usually occupied over 66% in the Japan Sea and thd Korean Strait samples occupied only 42% of the catches in August, while cladocerans and chaetognaths were relatively abundant, i. e., 15 and 18% of the total organisms. The most dominant species of copepods and chaetognaths were Paracalanus parvus, Oithona similis, Acartia clausi, Calanus helgolandicus, Sagitta enflata, S. bedoti, S. elegans and S. crassa.

• Strategy21
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• s.46
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• pp.239-276
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• 2020

The failure of early economic sanctions aimed at hurting the overall economies of targeted states called for a more sophisticated design of economic sanctions. This paved way for the advent of 'smart sanctions,' which target the supporters of the regime instead of the public mass. Despite controversies over the effectiveness of economic sanctions as a coercive tool to change the behavior of a targeted state, the transformation from 'comprehensive sanctions' to 'smart sanctions' is gaining the status of a legitimate method to impose punishment on states that do not conform to international norms, the nonproliferation of weapons of mass destruction in this particular context of the paper. The five permanent members of the United Nations Security Council proved that it can come to an accord on imposing economic sanctions over adopting resolutions on waging military war with targeted states. The North Korean nuclear issue has been the biggest security threat to countries in the region, even for China out of fear that further developments of nuclear weapons in North Korea might lead to a 'domino-effect,' leading to nuclear proliferation in the Northeast Asia region. Economic sanctions had been adopted by the UNSC as early as 2006 after the first North Korean nuclear test and has continually strengthened sanctions measures at each stage of North Korean weapons development. While dubious of the effectiveness of early sanctions on North Korea, recent sanctions that limit North Korea's exports of coal and imports of oil seem to have an impact on the regime, inducing Kim Jong-un to commit to peaceful talks since 2018. The purpose of this paper is to add a variable to the factors determining the success of economic sanctions on North Korea: preventing North Korea's evasion efforts by conducting illegal transshipments at sea. I first analyze the cause of recent success in the economic sanctions that led Kim Jong-un to engage in talks and add the maritime element to the argument. There are three conditions for the success of the sanctions regime, and they are: (1) smart sanctions, targeting commodities and support groups (elites) vital to regime survival., (2) China's faithful participation in the sanctions regime, and finally, (3) preventing North Korea's maritime evasion efforts.

• Analyses & Alternatives
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• v.7 no.1
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• pp.229-258
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• 2023

For the main countries of the Asia-Pacific region, the United States, China and Russia, a situation of "new normality" is emerging. Moreover, for each of the countries, this "new normality" has its own meaning. For the United States, this is an aggravation of the military confrontation with China in the Taiwan Strait. For China, this is an increase in the degree of rivalry with the United States and a slowdown in the pace of economic development with a very high probability of their decline in the future. For Russia, this is an almost complete curtailment of relations with the United States against the background of a special military operation and imposed sanctions. These nuances, in addition to the results of the 20th CPC Congress, will determine the main trends in Sino-American and Sino-Russian relations. It seems that China's attitude towards Russia will not change against the background of the Ukrainian crisis. Beijing will maintain a position of "benevolent neutrality" towards Moscow. At the same time, the balance between "goodwill" and "neutrality" may vary depending on the scope of Sino-Russian cooperation. For example, in the economic sphere, Chinese companies will be afraid to cooperate with Russian partners for fear of secondary sanctions. However, in general, Russia will retain its importance for China as the strongest anti-American pole. In relations with the United States, China will continue to firmly defend its interests, while at the same time not excluding the normalization of relations with Washington in certain areas of cooperation: strategic stability, non-traditional threats, ecology, etc. In general, the decisions of the 20th CPC Congress do not allow us to say either in favor or against the idea of China's readiness to resume dialogue with the United States in the post-congress period. Sino-American relations, as noted above, have their own logic and will probably continue to develop within its framework. However, so are Sino-Russian relations. Within the framework of these logics, Beijing seems to continue to balance between the two vectors of its foreign policy. On the one hand, this is the development of bilateral cooperation with Russia in order to strengthen its own negotiating positions in the confrontation with the United States: military cooperation with an emphasis on joint exercises, political cooperation based on anti-Americanism, economic cooperation with an eye to the risks of secondary sanctions. On the other hand, it is unacceptable for China to recognize the collapse of Ukraine, the inadmissibility of a direct military clash with the United States and the extreme undesirability of further aggravation of relations with the United States on the factor of Chinese friendship with Russia.