• Proceedings of the Korean Society of Fisheries Technology Conference
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• 2003.05a
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• pp.164-165
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• 2003

본 연구는 영일만 만내 수괴의 거동에 영향을 미칠 것으로 판단되는 가용 강우량, 증발량, 바람 등 기상조건의 영향을 검토ㆍ분석하고, 그림 1의 영일만 정선해양관측의 수온ㆍ염분 자료와 연안정지 수온관측자료를 수집ㆍ분석하여 영일만 해역에서의 동해 고유수와 만내 연안수와의 혼합과정을 규명하고자하였다. 이를 통해 영일만수괴의 만내 연안수와 동해 고유수와의 상호관련성과 만내 해수의 수평ㆍ연직순환류 발생 메카니즘에 대해서 고찰하고자 하였다. (중략)

• Journal of the Korean Society for Marine Environment & Energy
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• v.8 no.3
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• pp.140-147
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• 2005

We investigated the interactions between coastal waters of the Yeongil Bay, Korea, and oceanic waters of the Eastern Sea, as wet 1 as the development mechanism of vertical circulation currents in the bay. The oceanic waters of the bay have an average water temperature of $12.2{\sim}18.4^{\circ}C$ and salinity of $33.32{\sim}34.43$ PSU. Results of spectral analysis have shown that the period of revolution between oceanic and coastal waters is about 0.84-0.91 years in the surface waters and 1.84 years in the bottom layer. The wind direction in the bay shifts between SW and NE, with the main wind direction being SW during the winter period, and water mass movement is influenced by such seasonal variations in wind direction. Vertical circulation currents in the bay are structured by two phenomena: the surface riverine outflow layer from the Hyeong-san River into the open sea and the bottom oceanic inflow layer with high-temperature and salinity into the bay. These phenomena start the spring when the water mass is stable and become stronger in the summer when the surface cold water develops over a 10-day period. Consequently, tidal currents have little influence in the bay; rather, these vertical and horizontal circulation currents play an important role in the transport of the pollutant load from the inner bay to the open sea.

• Proceedings of KOSOMES biannual meeting
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• 2018.06a
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• pp.142-142
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• 2018

• Proceedings of the Korean Society of Fisheries Technology Conference
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• 2001.10a
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• pp.67-68
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• 2001

멸치를 어획하는 주 어구인 초망어업은 우리나라 남해안과 제주도 연안에서 행해지는 고유어법으로서, 이러한 초망어업은 큰 챗대 1개와 작은 챗대 1개는 반 기계적으로, 콧대 1개와 그물작업은 인력으로 조작되고 있는데, 멸치어군의 집어는 집어등을 선수 전방에 설치하여 2-3노트의 속력으로 항해하면서 멸치어군을 표층으로 부상시킨다. 이때 집어등만으로 멸치어군이 표층으로 부상하지 않으면 쇠파이프로 어선의 외관을 두드리거나 또는 기관 회전수를 빠르게 하여 공회전 시키면서 수중 소음을 발생시켜 멸치어군을 표층으로 유집시킨다. (중략)

• Journal of the Korean Society for Marine Environment & Energy
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• v.10 no.1
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• pp.59-65
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• 2007

Rapid variation of coastal ecosystem in the East Sea of Korea, such as fishery resource variation and subtropical chang of bentic flora, accordong to the global warming are actually noticed. In this study we try to identify the characterics of water mass existing in this coastal area and to consider the variation of their physical and chemical properties using data of temperature, salinity and dissolved oxygen obtained by National Fisheries Research & Development Institute from 1960 to 2005. The temperature of all water mass rise during last 45 years; the rise of North Korea Cold Water temperature (about $2.33^{\circ}C$) is 1.5 times higher than that of Tsushima warm water (about $1.6^{\circ}C$), and the temperature rise of Tsushima Surface Water, directly affected by climate chang is $2.57^{\circ}C$, higher than the atmospheric temperature rise during same period, indicating that subtropical change makes progress more rapidly in the coastal marine ecosystem than in the land ecosystem. Otherwise, the salinity in the surface water decrease $0.29\%_{\circ}$ during last 45 years due to the rising trend of rainfall with atmospheric temperature. The dissolved oxygen concentration in the all water mass make a decreasing trend. Specially for the North Korea Cold Water, the dissolved oxygen concentration diminish 0.021 mg/l per year and the decrease in the East Sea Proper Water indicate a change of inner water circulation system.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.27 no.6
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• pp.782-786
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• 1994

Integrated finite difference method (IFDM) is used to solve one dimensional free oscillation problem in the coastal area. To evaluate the solution accuracy of IFDM in free oscillation analysis, two finite difference equations based on area discretization method and point discretization method are derived from the governing equations of free oscillation, respectively. The difference equations are transformed into a generalized eigenvalue problem, respectively. A numerical example is presented, for which the analytical solution is available, for comparing IFDM to conventional finite difference equation (CFDM), qualitatively. The eigenvalue matrices are solved by sub-space iteration method. The numerical results of the two methods are in good agreement with analytical ones, however, IFDM yields better solution than CFDM in lower modes because IFDM only includes first order differential operator in finite difference equation by Green's theorem. From these results, it is concluded that IFDM is useful for the free oscillation analysis in the coastal area.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.30 no.5
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• pp.859-867
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• 1997

In order to utilize the processing wastes of squid, chitosans were manufactured from the pens of domestic squid, Todarbdes pacificus and foreign squid, Ommastrephes bartrami and then, its rheological properties were studied. The amounts of nitrogen and minerals of the domestic squid pens were $11.4\%\;and\;0.1\%$ respectively, whereas those of its chitosan were $7.5\%\;and\;0.2\%$. In case of foreign squid pen and chitosan, the amounts of nitrogen and minerals were $12.1\%,\;0.8\%\;and\;7.8\%,\;0.2\%$ respectively. Intrinsic viscosity $([\eta]) $ of domestic and foreign squid pen chitosans were decreased with increasing pH from 3.4 to 5.4 which might be due to the reduced repulsion in inter- of intra- chitosan molecules. Intrinsic viscosity of the domestic and foreign squid pen chitosans were decreased with increasing NaCl concentration thus indicated that the domestic and foreign squid pen chitosans were polyelectrolyte molecules and stiffness of squid pen thitosans were 0.11 similar to that of k-carrageenan. Flow type of squid pen chitosan solutions were pseudoplastic fluids without yield stress by the viscosity measurement. But the squid pen chitosan solutions showed newtonian fluid up to $0.15\~0.24\%$ concentration for domestic and $0.21\~0.24\%$ concentration for foreign at $10\~50\%$. Concentration dependence of consistency index in infinitive dilute domain (Kc) were higher in the dilute domain than entangled domain. Activation energies (Ea) of the squid pen chitosans were 3.7, 6.3, 3.6, 4.0 and 4.1 Kcal/g moi for domestic and 3.2, 3.1, 3.4, 3.8 and 3.6 Kcal/g mol for foreign at 0.1, 0.15, 0.25, 0.35 and $0.5\%$, respectively.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.16 no.4
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• pp.305-315
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• 1983

A survey was carried out from July to December in 1979 and 1982 for the investigation of oceanographic conditions and phytoplankton in Seogwipo coastal area. Although a peculiar coastal sea water is formed by in flowing of fresh water, this is developed mainly in summer and disappeared or weakened in its strength after November. However, this coastal sea water covers only the surface while in mid and bottom layer open sea water is approached to the coast. Therefore, coastal and open sea water appears simultaneously in narrow sea area. Mean values of nutrient concentrates on surface layer during investigating period were $3.72{\sim}16.34{\mu}g-at/l$ in silicate, $1.98{\sim}5.53{\mu}g-at/l$ in nitrate and $0.34{\sim}0.90{\mu}g-at/l$ in phosphate. These showed slight differences among places but in general coastal side were lower than open sea side. Phosphates which is the lowest in concentrates among nutrients in Seogwipo coastal area shows almost similar value with Jinhae Bay but higher than open sea water around 10 mile south of Seogwipo. In general, seasonal changes of nutrients in investigating period shows a tendency of the lowest in October, increasing in November, and again slight decrease in December. As a phytoplankton fauna, 48 species, 1 variety and 2 breeds of Diatoms, 29 species, 3 varieties and 1 breed fo Dinoflagellates, and 1 species each of Chroococcus and Trichoceratium were found. Monthly predominant species are all neritic: Rhizosolenia sp. and Ceratium sp. in August, Chaetoceros sp., Ceratium sp. and Peridinium sp. in September, Astrionella sp. and Peridinium sp. in October, Astrionella sp., Navicula sp. and Chaetoceros sp. in November Among these, Rhizosolenia alata f. gracillima in August and Astrionella gracillima in November are remarkable predominant.

• Korean Journal of Ichthyology
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• v.2 no.1
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• pp.36-46
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• 1990

Samples were obtained with a set net during 7 months between March and October in 1987 off the coast of Hwasun, southern part of Cheju Island. Most of organisms, representing 36 species, were less than 20cm(96%) in length, and 30g(74%) in weight. The four most abundant species were jack mackerel, Trachurus japonicus ; squid, Todarodes pacificus ; mackerel, Scomber japonicus ; and Apogon semilineatus, which comprised about 89% of the total individuals and about 70% of the total weight. Diversity index, the number of species and information index for individual were high in early spring, even though biomass was not abundant. On the other hand, diversity index and information index for individual were relatively high in August in spite of low occurrence of the species number. A cluster analysis of 24 species which appeared more than twice during the 7 samplings were illustrated from the similarity matrix. All of the 24species were grouped at the 0.14 similarity level. They were divided into four groups at 0.50 level.

• Journal of Navigation and Port Research
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• v.32 no.10
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• pp.813-819
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• 2008

Many shipping companies have suffered about high oil cost and environment regulation as people are concerned about the environment, therefore concentrating on energy using efficiency of the ship. The Skysails Company of Germany developed Skysails System for 4 years, making Shipping Company take interest under such situation. Skysails System uses a large kite in the ship, decreasing fuel expenses. So examination and utility analysis on Skysails System application are a necessity by using weather condition in the Coastal Waters of Korea where feeder network was well-developed. As a result, we could find out the system's efficacy on fuel saving and environment cost saving.