• Korean Journal of Fisheries and Aquatic Sciences
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• v.11 no.4
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• pp.219-225
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• 1978

Several samples of tile dried purple laver grown and processed at the major laver producing districts, i. e Mokpo, Wando, Hadong and Jangrim, along the southern coast of Korea were Quantitatively investigated to determine composing patterns of the fatty acids by gas-liquid chromatography. The total lipid contents in dried purple laver of Hadong were $1.8\%$ being the highest value. Upon analyzing fatty acid composition, some differences were observed in their quantitative distribution at different growing places. Dried purple laver of Wando contained mainly $C_{16:0},\;C_{18:1},\;C_{16:1}\;and\;C_{17:0}$ fatty acids, that of Mokpo contained $C_{16:0},\;C_{20:5},\;C_{18:1}\;and\;C_{16:1}$ fatty acids, and that of Hadong $C_{16:0},\;C_{20:5},\;C_{18:0}\;and\;C_{20:1}$ fatty acids, and that of Jangrim $C_{20:5},\;C_{16:0},\;C_{18:1}\;and\;C_{18:0}$ fatty acids, each in order of acid quantity. In regard to the composing pattern of carbon number of fatty acids, the dried purple laver o Mokpo, Hadong, and Jangrim contained $C_{16},\;C_{18}\;and\;C_{20}$ fatty acids with the identical distributional pattern, while that of Jangrim contained $C_{16},\;C_{18}\;and\;C_{17}$ fatty acids as major components. Dried Purple laver of Jangrim contained especially high amount of $C_{20:5}$ fatty acids.

• Journal of Navigation and Port Research
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• v.38 no.3
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• pp.217-225
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• 2014

The system that covers gathering, integrating, exchanging, presenting and analyzing of information within ships and shores for the safety and security in Marine Environment is known as e-Navigation Policy. Northern Europe has been conducting research and development. It came up into a concept that deals with ship's route information between vessels as well as vessels to shores which is better known as route exchange system. The research showed substantial advantages on navigational safety by exchanging the route information between vessels in vicinity and vessels to shores. Therefore, upon the adaptation of route exchange System as a major function in integrated navigational system, the existing procedures in VTS could be changed for betterment. In this study, it was verified the effectiveness of route exchange system by the adaptation of a recent collision accident occurred in Korean coast and suggested that route exchange system which would be carried out by the discretion of VTS center in VTS area. Finally, it proposed the new functions for outstanding services and procedures of integrating traffic organization services on coastal VTS for an effective route exchange system in Korean coastal area.

• Korean Journal of Plant Resources
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• v.22 no.1
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• pp.102-110
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• 2009

This study examined the halophyte community and soil analysis according to habitat in representative 18 salt marshes of southern and western coasts of Korea from July 2006 to April 2008 and suggested basic materials for vegetational restoration of these aras. First, the survey area was classified into coastal and estuarine marshes. Then, the coastal marshes were classified into clay marsh, sand gravel marsh, and sand marsh, and the esturarine marshes, into salt swamp and estuary marsh. Major plant communities according to habitat pattern were Phragmites communis, Carex scabrifolia, and Suaeda japonica community in the clay marsh; Phragmites communis, Zoysia sinica, Carex scabrifolia, Salicornia herbacea, Artemisia fukudo, Suaeda martima community in the sand gravel marsh; Elymus mollis, Carex kobomugi, and Vitex rotundifolia community in the sand mars; Phragmites communis, Zoysia sinica, Suaeda martima, and Carex scabrifolia community in the salt swamp, and Suaeda japonica, Phragmites communis, Carex scabrifolia, and Suaeda asparagoides community in the estuary marsh. The soil environment of halophyte community area showed a difference to soil and halophyte community according to habitat characteristics of halophyte. Thus, to restore salt mashes in the coast area, it is advantageous for the stable settlement, germination, and growth of halophyte to grasp physical and physicochemical characteristics of habitat soil in the salt marshes, to select halophyte suitable to these habitat conditions, and to expand gradually in the natural vegetation area after transplantation.

• Journal of the Korean Society of Marine Environment & Safety
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• v.23 no.1
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• pp.98-103
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• 2017

In this study, contributes to improving the state of this problem using cavitation by ultrasonic energy to reduce fuel costs, which take up a considerable part of ship operation costs, by making the use of on-board blended fuel oil more stable. An experiment simulating on-board blending methods was completed. Fuel (M.G.O & MF-180) was mixed at a volume ratio of 0.25:0.75 and, 0.75:0.25, and the effect of ultrasonic energy on blended fuel oil was examined after applying ultrasonic energy to blended fuel oil using an ultrasonic treatment unit. With the results, we confirmed the blending problem reported by vessels and residual carbon was reduced by up to 28.4%. In addition, based on the results for reduction of residual carbon content and dispersion stability, it was confirmed that the collapse pressure of the cavity due to the ultrasonic energy was effective to atomization of fuel particle and the temporary availability of mixed fuel containing a heavy fuel increased.

• Journal of the Korean Society of Marine Environment & Safety
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• v.28 no.6
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• pp.1054-1062
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• 2022

The population of Korea's solar salt-producing regions is rapidly aging, resulting in a decrease in the number of productive workers. In solar salt production, salt collection is the most labor-intensive operation because existing salt collection vehicles require human operators. Therefore, we intend to develop an unmanned solar salt collection vehicle to reduce manpower requirements. The unmanned solar salt collection vehicle is designed to identify the salt collection status and location in the salt plate via color detection, the color detection performance is a crucial consideration. Therefore, an image processing algorithm was developed to improve color detection performance. The algorithm generates an around-view image by using resizing, rotation, and perspective transformation of the input image, set the RoI to transform only the corresponding area to the HSV color model, and detects the color area through an AND operation. The detected color area was expanded and noise removed using morphological operations, and the area of the detection region was calculated using contour and image moment. The calculated area is compared with the set area to determine the location case of the collection vehicle within the salt plate. The performance was evaluated by comparing the calculated area of the final detected color to which the algorithm was applied and the area of the detected color in each step of the algorithm. It was confirmed that the color detection performance is improved by at least 25-99% for salt detection, at least 44-68% for red color, and an average of 7% for blue and an average of 15% for green. The proposed approach is well-suited to the operation of unmanned solar salt collection vehicles.

• Journal of the Korean Society of Marine Environment & Safety
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• v.29 no.1
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• pp.76-85
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• 2023

Demand for hydrogen as a renewable energy resource is increasing. However, unlike conventional fossil fuels, hydrogen requires a dedicated refueling station for fuel supply. A risk assessment of hydrogen refueling stations must be undertaken to secure the infrastructure. Therefore, in this study, a risk assessment for hydrogen refueling stations was conducted through both qualitative and quantitative risk assessments. For the qualitative evaluation, the hydrogen dispenser module was evaluated as two nodes using the hazard and operability (HAZOP) analysis. The risk due to filter clogging and high-pressure accidents was evaluated to be high according to the criticality estimation matrix. For the quantitative risk assessment, the Hydrogen Korea Risk Assessment Module (Hy-KoRAM) was used to indicate the shape of the fire and the range of damage impact, and to evaluate the individual and social risks. The individual risk level was determined of to be as low as reasonably practicable (ALARP). Additional safety measures proposed include placing the hydrogen refueling station about 100m away from public facilities. The social risk level was derived as 1E-04/year, with a frequency of approximately 10 deaths, falling within the ALARP range. As a result of the qualitative and quantitative risk assessments, additional safety measures for the process and a safety improvement plan are proposed through the establishment of a restricted area near the hydrogen refueling station.

• Journal of the Korean Society of Marine Environment & Safety
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• v.30 no.2
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• pp.200-208
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• 2024

The occurrence a fire on a training ship with a large number of people on board can lead to severe casualties. Hence the Seafarers' Act and Safety Life At Sea(SOLAS) emphasizes the importance of the abandon ship drill. Therefore, in this study, the training ship of Mokpo National Maritime University, Segero, which has a large number of people on board, was selected as the target ship and the likelihood and severity of fire accidents on each deck were predicted through the preliminary hazard analysis(PHA) qualitative risk assessment. Additionally, assuming a fire in a high-risk area, a simulation of evacuation time and population density was performed to quantitatively predict the risk. The the total evacuation time was predicted to be the longest at 501s in the meal time scenario, in which the population distribution was concentrated in one area. Depending on the scenario, some decks had relatively high population densities of over 1.4pers/m², preventing stagnation in the number of evacuees. The results of this study are expected to be used as basic data to develop training scenarios for training ships by quantifying evacuation time and population density according to various evacuation scenarios, and the research can be expanded in the future through comparison of mathematical models and experimental values.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.49 no.5
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• pp.689-693
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• 2016

Sargassum golden tides occurred in Shinan-gun and Jeju Island, Korea, between January and May 2015. In Shinangun, 5,180 tons of Sargassum were removed from 3,339 ha of coastline, while 20,000 tons were removed from Jeju Island. The huge floating masses of seaweed caused damage to fisheries in Shinan-gun including abalone sea cage, Pyropia and Saccharina farms off the southwest coast of Korea. Drifting Sargassum also washed ashore on Jeju Island. The species of Sargassum in these golden tides was identified as S. horneri (Turner) C. Agardh, based on morphology and molecular data, and it appears to have originated from the East China Sea. This is the first report on Sargassum golden tides causing damage to fisheries in Korea.

• Journal of the Society of Naval Architects of Korea
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• v.49 no.5
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• pp.410-415
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• 2012

An experimental study is carried out to investigate the near-wake characteristics of a NACA 0018 foil with a flat plate. Two-frame grey-level cross correlation PIV method is used to measure the local flow characteristic around a pitch damping foil to control the vertical motion of high speed crafts in a circulating water channel. The analysis also includes angles of attack 10 and 20 degrees respectively. Reynolds number $Re{\fallingdotseq}3.5{\times}10^4$ based on the chord length(C=100mm) of NACA0018 has been applied during the whole experiments. The distance between the foil and the flat plate is D/C=0.5, 1.0 and 1.5 respectively. The channel effect according as the distance between the foil and the flat plate has a close relation with the velocity distributions around the foil. In the wake of 20-degree of attack, the complex turbulent flow and a thick boundary layer are formed due to the processes of vortex generation and dissipation.

• The Korean Journal of Ecology
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• v.11 no.4
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• pp.175-192
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• 1988

The coastal vegetation of the southwestern coast of Korea was surveyed by the Braun-Blnquet's phytosociological sKDICe and its soil properties were also determined. Comparing with the coastal vegetation of Korea, Japan and Europe, the vegetation of this area could be classified into as follows; A. Thero-Salicornietea R. Tx. 1954(Salicor-nietum herbaceae assoc. nov.). B. Thero-Suaedetea Rivas Martwez 1979 (Suaedetum japonicae Miyawaki et Ohba 1966, Suaeda maritima commuity, Atriplici-Suaedetum maritimi Miyawaki et Ohba 1965, Suaeda asparagoided community) C. Asteretea tripolium Westhoff et Beeftink 1962 (Zoysietum sinice Ohba, Miyawaki et Tx. 1973, Limonietum tetragoni Miyawaki et Ohba 1969, Artemisietum scopariae assoc. nov., Aster tripolium community, Atriplex, gmelini community) D. Phragmitetea Tx. et Prsg. 1942 (Triglochietum maritimae assoc. nov., Carcetum scabrifoliae Miyawaki et Ohba 1969, phragmites communis community, Pyaceluretum latifolii Miyawaki et Okuda 1972, Scirpus fluviatilis community) E. Salsoletea komarovil Ohba, Miyawaki et Tx. 1973(Salsola komarovi community) F. Glehnietea littoralis ohba, Miyawaki et Tx. 1973(Caricetum pumilae assoc. nov., Meserschmidia sibirica community, Lysimachia mauri-tiana community Ishaemum anthephoroides community, Elymus mollis commuity, carex kobomugi community, Ixeris repens community) G. Viticetea rotundifoliae Ohba, Miyawaki et Tx. 1973 (Imperato cylindricae-Viticetum rotundifoliae ohba, Miyawaki ex Tx. 1973) and Opuntia ficus-indica var. saboten community. Among the soil properties, water potential seems to be one fo the most important factor on the distribution of the coastal plant community and it might be highly affected by water content in sand and salinity in low marsh.