• Journal of the Korean Society of Marine Environment & Safety
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• v.28 no.6
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• pp.882-889
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• 2022

In this study, to understand the factors influencing the flow change the Tsushima Warm Current (TWC), the correlation between the volume transport the TWC, El Niño Southern Oscillation (ENSO), and Pacific Decadal Oscillation (PDO) was analyzed. A calculation of the monthly volume transport of TWC for 25 years (1993-2018) revealed that the seasonal fluctuation cycle was the largest in summer and smallest in winter. Power spectrum analysis to determine the periodicity of the TWC volume transport, Oceanic Niño Undex (ONI), and PDO indicated that the TWC volume transport peaked at a one year cycle, but ONI and PDO showed no clear cycle. Further, to understand the correlation between the TWC transport volume and ONI and PDO, the coherence estimation method was used for analysis. The coherence of ONI and PDO had a high mutual contribution in long-period fluctuations of three years or more but had low mutual contribution in short-period fluctuations within one year. However, the coherence value between the two factors of the TWC volume transport and PDO was 0.7 in the 0.8-1.2 year cycle, which had a high mutual contribution. Meanwhile, the TWC volume transport and PDO have an inverse correlation between period I (1993-2002) and period III (2010-2018). When the TWC maximum transport volume (2.2 Sv or more) was high, the PDO index showed a negative value below -1.0, and the PDO index showed a positive value when the TWC maximum transport volume was (below 2.2 Sv). Therefore, using long-term PDO index data, changes in the TWC transport volume and water temperature in the East Sea coastal area could be predicted.

• Journal of the Korean Society of Marine Environment & Safety
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• v.27 no.7
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• pp.924-942
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• 2021

The expansion of the Changjiang Diluted Water (CDW) plume during summer is known to be a major factor influencing phytoplankton diversity, community structure, and the regional marine environment of the northern East China Sea (ECS). The discharge of the CDW plume was very high in the summer of 2020, and cruise surveys and stationary monitoring were conducted to understand the dynamics of changes in environmental characteristics and the impact on phytoplankton diversity and community structure. A cruise survey was conducted from August 16 to 17, 2020, using R/V Eardo, and a stay survey at the Ieodo Ocean Research Station (IORS) from August 15 to 21, 2020, to analyze phytoplankton diversity and community structure. The southwestern part of the survey area exhibited low salinity and high chlorophyll a fluorescence under the influence of the CDW plume, whereas the southeastern part of the survey area presented high salinity and low chlorophyll a fluorescence under the influence of the Tsushima Warm Current (TWC). The total chlorophyll a concentrations of surface water samples from 12 sampling stations indicated that nano-phytoplankton (20-3 ㎛) and micro-phytoplankton (> 20 ㎛) were the dominant groups during the survey period. Only stations strongly influenced by the TWC presented approximately 50% of the biomass contributed by pico-phytoplankton (< 3 ㎛). The size distribution of phytoplankton in the surface water samples is related to nutrient supplies, and areas where high nutrient (nitrate) supplies were provided by the CDW plume displayed higher biomass contribution by micro-phytoplankton groups. A total of 45 genera of nano- and micro-phytoplankton groups were classified using morphological analysis. Among them, the dominant taxa were the diatoms Guinardia flaccida and Nitzschia spp. and the dinoflagellates Gonyaulax monacantha, Noctiluca scintillans, Gymnodinium spirale, Heterocapsa spp., Prorocentrum micans, and Tripos furca. The sampling stations affected by the TWC and low in nitrate concentrations presented high concentrations of photosynthetic pico-eukaryotes (PPE) and photosynthetic pico-prokaryotes (PPP). Most sampling stations had phosphate-limited conditions. Higher Synechococcus concentrations were enumerated for the sampling stations influenced by low-nutrient water of the TWC using flow cytometry. The NGS analysis revealed 29 clades of Synechococcus among PPP, and 11 clades displayed a dominance rate of 1% or more at least once in one sample. Clade II was the dominant group in the surface water, whereas various clades (Clades I, IV, etc.) were found to be the next dominant groups in the SCM layers. The Prochlorococcus group, belonging to the PPP, observed in the warm water region, presented a high-light-adapted ecotype and did not appear in the northern part of the survey region. PPE analysis resulted in 163 operational taxonomic units (OTUs), indicating very high diversity. Among them, 11 major taxa showed dominant OTUs with more than 5% in at least one sample, while Amphidinium testudo was the dominant taxon in the surface water in the low-salinity region affected by the CDW plume, and the chlorophyta was dominant in the SCM layer. In the warm water region affected by the TWC, various groups of haptophytes were dominant. Observations from the IORS also presented similar results to the cruise survey results for biomass, size distribution, and diversity of phytoplankton. The results revealed the various dynamic responses of phytoplankton influenced by the CDW plume. By comparing the results from the IORS and research cruise studies, the study confirmed that the IORS is an important observational station to monitor the dynamic impact of the CDW plume. In future research, it is necessary to establish an effective use of IORS in preparation for changes in the ECS summer environment and ecosystem due to climate change.

• Journal of Navigation and Port Research
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• v.28 no.10 s.96
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• pp.899-908
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• 2004

The rise of income and introduction of 5 day a week working system give korean people opportunities to enjoy their leisure time. And many korean people have much interest in oceanic sports such as yachting and also oceanic leisure equipments. With the popularization and development of the equipments, the scope of oceanic activities has been expanding in Korea just as in the advanced oceanic countries. However, The current conditions for the sports in Korea are not advanced and even worse than underdeveloped countries. In order to develop the underdeveloped resources of Korean marina, we need to customize the marina models of advanced nations to serve the specific needs and circumstances of Korea As such we have carried out a comparative analysis of how Austrailia, Newzealand, Singapore, japan and Malaysia operate their marina, reaching the following conclusions. Firstly, in marina operations, in order to protect personal property rights and to preserve the environment, we must operate membership and non-membership, profit and non-profit schemes separately, yet without regulating the dress code entering or leaving the club house. Secondly, in order to accumulate greater value added, new sporting events should be hosted each year. There is also the need for an active use of volunteers, the generation of greater interest in yacht tourism, and the simplification of CIQ procedures for foreign yachts as well as the provision of language services. Thirdly, a permanent yacht school should be established, and classes should be taught by qualified instructors. Beginners, intermediary, and advanced learner classes should be managed separately with special emphasis on the dinghy yacht program for children. Fourthly, arrival and departure at the moorings must be regulated autonomically, and there must be systematic measures for the marina to be able, in part, to compensate for loss and damages to equipment, security and surveillance after usage fees have been paid for. Fifthly, marine safety personnel must be formed in accordance with Korea's current circumstances from civilian organizations in order to be used actively in benchmarking, rescue operations, and oceanic searches at times of disaster at sea.

• Korean Journal of Environment and Ecology
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• v.16 no.1
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• pp.34-45
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• 2002

Of the four tidal flat areas(Yeocha-ri, Dongmak-ri, Sundu-ri and Donggum-ri) on Southern Ganghwa Island, the distribution of migratory waterbirds showed a difference in the numbers of individuals and species. Higher numbers of individuals and species were observed on the Yeocha-ri tidal flat. The dominant waterbirds species at the four areas was the Dentin(Calidris alpina). This species showed an occupancy rate(42.0-79.1%) on the Yeocha-ri tidal flat, which was much higher relative to the other areas. The Yeocha-ri tidal flats were higher relative to MSL than the other tidal flats. When the Dongmak-ri tidal flat was covered by sea water, the Yeocha-ri tidal flat was 0.0317$\textrm{km}^2$ in area and on this space we observed many resting waterbirds. The biomass of the waterbirds' potential prey on the Yeocha-ri tidal flat was higher(1.6~2.5$\times$) than other tidal flats. Twenty-three species and 266 individuals were found on the Yeocha-ri tidal flat, which was higher than the tidal flats. The food of Dunlin, which was the dominant species in these four areas, was mainly Reticunassa festiva and Umbonium thomasi(Gastropoda) and Perinereis aibuitensis(Polychaeta). A Dunlin(38.11g) used to eat 1,295 individuals of these food items for daily basal energy. Gastropod, its density was highest on Yeocha-ri tidal flats. The distribution of waterbirds seemed to be closely related with the distribution of the benthos, space and safety of resting site. We suggest that the environments of tidal flats, which are rich foraging habitats, are important factors for conservation of waterbirds.

• Korean Security Journal
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• no.41
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• pp.293-326
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• 2014

Piracy is a worldwide issue, but the deteriorating security situation in the seas off Somalia, the Gulf of Aden and the wider Western Indian Ocean between 2005 and 2012 and in the increasing number of attacks in the Gulf of Guinea are a major problem. The depth of concern for the problem internationally is amply demonstrated by the levels of co-operation and coordination among naval and other forces from several countries that have assembled in the west Indian Ocean region and the Gulf of Aden to escort ships carrying humanitarian aid to Somalia and to protect vulnerable shipping. Notwithstanding this unprecedented effort, the vast sea area in which the pirates now operate makes it difficult to patrol and monitor effectively, particularly with the limited resources available. More resources, in the form of naval vessels and aircraft, are needed and at every opportunity the IMO encourages Member Governments to make greater efforts to provide the additional naval, aerial surveillance and other resources needed through every means possible. IMO provide interim guidance and recommendations to be taken into account when considering the use of PCASP(privately contracted armed security personnel) if and when a flag State determines that such a measure would be lawful and, following a full risk assessment, appropriate. The interim guidance and recommendations of IMO are not intended to endorse or institutionalize the use of armed guards. Therefore, they do not represent any fundamental change of policy by the Organization in this regard. It is for each flag State, individually, to decide whether or not PCASP should be authorized for use on board ships flying their flag. If a flag State decides to permit this practice, it is up to that State to determine the conditions under which authorization will be granted. Therefore, Korea should be introduced rationally PCASP for safe shipping. PCASP on board ships is much the same to special guard personnel of security services industry act. Act plan of Oceans and fisheries ministry on PCASP collides with special guard personnel system of National Police Agency. Rather than new law making, PCASP regukations have to be included in security services industry act. Management Agency of PCASP is to not Oceans and fisheries ministry, but Central Headquarters Korea Coast Guard of Public Safety and Security Ministry because of specialty and closely connection.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.18 no.2
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• pp.89-103
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• 2013

National demands for the ocean forecasting system have been increased to support economic activity and national safety including search and rescue, maritime defense, fisheries, port management, leisure activities and marine transportation. Further, the ocean forecasting has been regarded as one of the key components to improve the weather and climate forecasting. Due to the national demands as well as improvement of the technology, the ocean forecasting systems have been established among advanced countries since late 1990. Global Ocean Data Assimilation Experiment (GODAE) significantly contributed to the achievement and world-wide spreading of ocean forecasting systems. Four stages of GODAE were summarized. Goal, vision, development history and research on ocean forecasting system of the advanced countries such as USA, France, UK, Italy, Norway, Australia, Japan, China, who operationally use the systems, were examined and compared. Strategies of the successfully established ocean forecasting systems can be summarized as follows: First, concentration of the national ability is required to establish successful operational ocean forecasting system. Second, newly developed technologies were shared with other countries and they achieved mutual and cooperative development through the international program. Third, each participating organization has devoted to its own task according to its role. In Korean society, demands on the ocean forecasting system have been also extended. Present status on development of the ocean forecasting system and long-term plan of KMA (Korea Meteorological Administration), KHOA (Korea Hydrographic and Oceanographic Administration), NFRDI (National Fisheries Research & Development Institute), ADD (Agency for Defense Development) were surveyed. From the history of the pre-established systems in other countries, the cooperation among the relevant Korean organizations is essential to establish the accurate and successful ocean forecasting system, and they can form a consortium. Through the cooperation, we can (1) set up high-quality ocean forecasting models and systems, (2) efficiently invest and distribute financial resources without duplicate investment, (3) overcome lack of manpower for the development. At present stage, it is strongly requested to concentrate national resources on developing a large-scale operational Korea Ocean Forecasting System which can produce open boundary and initial conditions for local ocean and climate forecasting models. Once the system is established, each organization can modify the system for its own specialized purpose. In addition, we can contribute to the international ocean prediction community.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.33 no.6
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• pp.529-532
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• 2000

To establish a food safety of dried layer, heat treatment effect on the bacterial density of dried layers was investigated. And a modified process developing experiment for dried layer products using closing type drying oven was carried out. tittle bacterial density difference on the dried layer products were found before and after heat treatment at $90^{\circ}C$ for 6 hrs called Hwaip treatment having been used for long term storage. Direct or indirect heat treatment of dried lavers using gas burner and frying pan reduced about 1 to 3 log cycle of viable cell count from $10^8\;CFU/g\;to\;10^5\;CFU/g$. Heat treatment by direct surface contact type cooking machine being used in the market place for cooked dried layer products could reduce the viable cell count on the layer product from $2.2{\times}10^5{\~}5.2{\times}10^7\;CFU/g\;to\;7.0{\times}10^2{\~}5.0{\times}10^5\;CFU/g$, Ultraviolet irradiation (20 W, 30 cm) to one or both side of the dried laver products reduced the viable cell count from $2.2{\times}10^6\;CFU/g\;to\;8.0{\times}10^5\;CFU/g\;and\;2.0{\times}10^5\;CFU/g$, respectively. The viable cell count of the dried layer products produced by modified process using a closing type dryer was about $10^3\;CFU/g$ and lower 3 log cycle than that in the products collected in market place and made by open type dryer.

• Food Science and Preservation
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• v.24 no.7
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• pp.908-914
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• 2017

Cold plasma (CP) was applied to examine microbial safety and physicochemical properties of rough rice. CP was generated in a square-shaped plastic container (250 W, 15 kHz, ambient air) and dielectric barrier discharge plasma treatment was applied for periods of 0, 10, and 20 min during 2 weeks at 4 and $25^{\circ}C$. As a result of observing changes in growth of microorganisms, 3.46-3.86 log CFU/g of total aerobic bacteria and 2.27-2.86 log CFU/g of mold were detected in the early stage of storage. The growth of total aerobic bacteria and mold was increased depending on the storage temperature and period, but there was no big difference between cultivars. Microbial analysis after storage showed that microorganisms of plasma-treated group were less grown approximately 1.50 log CFU/g. Moisture content of rough rice was decreased by storage temperature and periods. As for the amylose content, changes in the content by plasma were not observed in Samkwang, Cheongpum and Misomi, whereas Palbangmi showed a tendency to increase. The results of this study indicated that CP treatment improved the microbial quality of rough rice, but further studies should be conducted to reduce the deterioration of sensory quality induced by CP.

• Journal of Korean Society of Forest Science
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• v.45 no.1
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• pp.11-25
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• 1979

There was much mass movement at many different mountain side of Peong Chang area in Kwangwon province by the influence of heavy rainfall through August/4 5, 1979. This study have done with the fact observed through the field survey and the information of the former researchers. The results are as follows; 1. Heavy rainfall area with more than 200mm per day and more than 60mm per hour as maximum rainfall during past 6 years, are distributed in the western side of the connecting line through Hoeng Seong, Weonju, Yeongdong, Muju, Namweon and Suncheon, and of the southern sea side of KeongsangNam-do. The heavy rain fan reason in the above area seems to be influenced by the mouktam range and moving direction of depression. 2. Peak point of heavy rainfall distribution always happen during the night time and seems to cause directly mass movement and serious damage. 3. Soil mass movement in Peongchang break out from the course sandy loam soil of granite group and the clay soil of lime stone and shale. Earth have moved along the surface of both bedrock or also the hardpan in case of the lime stone area. 4. Infiltration seems to be rapid on the both bedrock soil, the former is by the soil texture and the latter is by the crumb structure, high humus content and dense root system in surface soil. 5. Topographic pattern of mass movement spot is mostly the concave slope at the valley head or at the upper part of middle slope which run-off can easily come together from the surrounding slope. Soil profile of mass movement spot has wet soil in the lime stone area and loose or deep soil in the granite area. 6. Dominant slope degree of the soil mass movement site has steep slope, mostly, more than 25 degree and slope position that start mass movement is mostly in the range of the middle slope line to ridge line. 7. Vegetation status of soil mass movement area are mostly fire field agriculture area, it's abandoned grass land, young plantation made on the fire field poor forest of the erosion control site and non forest land composed mainly grass and shrubs. Very rare earth sliding can be found in the big tree stands but mostly from the thin soil site on the un-weatherd bed rock. 8. Dangerous condition of soil mass movement and land sliding seems to be estimated by the several environmental factors, namely, vegetation cover, slope degree, slope shape and position, bed rock and soil profile characteristics etc. 9. House break down are mostly happen on the following site, namely, colluvial cone and fan, talus, foot area of concave slope and small terrace or colluvial soil between valley and at the small river side Dangerous house from mass movement could be interpreted by the aerial photo with reference of the surrounding site condition of house and village in the mountain area 10. As a counter plan for the prevention of mass movement damage the technics of it's risk diagnosis and the field survey should be done, and the mass movement control of prevention should be started with the goverment support as soon as possible. The precautionary measures of house and village protection from mass movement damage should be made and executed and considered the protecting forest making around the house and village. 11. Dangerous or safety of house and village from mass movement and flood damage will be indentified and informed to the village people of mountain area through the forest extension work. 12. Clear cutting activity on the steep granite site, fire field making on the steep slope, house or village construction on the dangerous site and fuel collection in the eroded forest or the steep forest land should be surely prohibited When making the management plan the mass movement, soil erosion and flood problem will be concidered and also included the prevention method of disaster.