• Korean Journal of Fisheries and Aquatic Sciences
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• v.56 no.6
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• pp.916-922
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• 2023

An abnormal shape of Bathyraja brachyurops was first reported from the catch of a bottom trawl in the southwest Atlantic Ocean in June 2022. Both pectoral fins of the specimen did not fuse with the head, resulting in a horn-like structure separated from the sides of the eyes. Analysis of mitochondrial DNA cytochrome c oxidase subunit I sequences showed that our specimen was perfectly matched to Bathyraja brachyurops registered with the National Center for Biotechnology Information. Our specimen possessed the following morphological features: a pair of flexible but elongated and pointed horns on the head; rough dorsal disc, densely covered with numerous small denticles on the head, anterior margin of pectoral fins and median line of the disc; a thorn between the first and second dorsal fins; and a pair of large ocelli at the base of pectoral fins. Unlike the normal B. brachyurops, our specimen had a slender clasper and no nuchal thorns, which may be related to the morphological abnormality. The horn-like structure on the head may be owing to the lack of fusion between the pectoral fins and head during early embryonic development.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.56 no.5
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• pp.741-748
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• 2023

This study evaluated the supplemental effects of linseed oil (LO) as a substitute for docosahexaenoic acid oil (DHAO) in the diet of juvenile Atlantic bluefin tuna. A control diet (DHA) was formulated to contain 65% enzyme-treated fish meal and 3% of DHAO. A LO diet was formulated to contain 1% LO replacing 1% DHAO in DHA diet. In a feeding trial, 300 juvenile bluefin tuna (initial body weight 1.15 g) were randomly divided into two concrete tanks (70 ton capacity) and fed one of the experimental diets for 13 days. Weight gain was higher in the LO group (519%) than in the control (443%) while survival and protein digestibility were similar between groups. The biological assessment of the tuna digestive organs did not differ between the DHA and LO groups. The fatty acid composition of the carcass showed that α-linolenic acid was only observed in the LO group, and there was no difference in the composition of eicosapentaenoic acid and docosapentaenoic acid between the groups. These results indicate that LO could be a dietary good oil source for Atlantic bluefin tuna without apparent negative effects.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.54 no.1
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• pp.32-37
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• 2018

The aim of this study is to investigate influence of moon light to the fishing of squid jigging fishery in the southwest Atlantic Ocean based on analyses of date taken from 127 vessels in Falkland fishing ground by squid jigging fishery from 2010 to 2015. Catch and CPUE were analyzed between the new moon and full moon phases. Catches of the new moon phase were higher than those of the full moon phase by 7.6% and CPUE expressed in mt/day-vessels and mt/line-day were also higher by 18.2%, 18.2% respectively. However, as a result of statistical analysis at a significance level of p > 0.05, no significant statistical differences in catch, mt/day-vessels and mt/line-day were found between the new moon and the full moon as a result of statistical analysis at a significance level of p > 0.05.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.18 no.2_spc
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• pp.275-289
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• 2020

In 2017, multimodal transportation tests for evaluating road, sea, and rail transport were performed by research institutes in the US, Spain, and the Republic of Korea. In this study, acceleration and strain data determined through road and sea tests were analyzed. It was investigated whether the load generated for each transport mode was amplified or attenuated according to the load transfer path. From the results, it was confirmed that the load transfer characteristics differed according to the transportation mode and loading path. The effects of strain determined through each test on the structural integrity of the spent nuclear fuel were also investigated. It was found that the magnitude of the measured strain had a negligible effect on the structural integrity of the spent nuclear fuel, considering its fatigue strength. The results for the acceleration and strain data analyses obtained in this study will be useful for scheduled domestic transportation tests under normal transport conditions.

• Convergence Security Journal
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• v.13 no.5
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• pp.67-75
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• 2013

South Korea suggest that the United States government should delay the date to hand over wartime operational control (OPCON). It is fixed on December 1, 2015. Typically the president's position as head of the executive authority is coming from the Commander-in-Chief of the Armed Forces. Now we should know the commander-in-chief of the nation's forces and the meaning of OPCON. The relationship between sovereignty and the commander-in-chief of the nation's forces is a little different. This is one of the efforts to enlarge the efficiency of Armed Forces. Of course, operational control is little control of the sovereign personnel, logistics, administration, discipline, organizing, training, etc. It does not control all matters. The current ROK Combined Forces Command itself is made with reference to the North Atlantic Treaty Organization(NATO). If we insist our own sovereignty is infringed because of OPCON, that claim is coated in irreparable damage to the national interest.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.28 no.2
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• pp.174-182
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• 1995

Using the optical data from the EUMELI 3 and 4 missions, the optical properties are discussed in relation to primary production in the oligotrophic zone of the Eastern Atlantic Ocean. The depth of euphotic layer $(Z_{eu})$, the total accumulated concentration of pigment $(C_{TOT})$ and the concentration of pigment (C) are 88m, $12.4mgm^{-2}\;and\;0.14mgm^{-3}$, respectively for the EUMELI 3 mission and 101.7m, $10.0mgm^{-2}\;and\;0.10mgm^{-3}$, respectively for the EUMELI 4 mission. The concentration of pigment is higher in autumn (EUMELI 3) than in spring (EUMELI 4). This indicates that the concentration of photosynthetic pigment has a close correlation with vertical attenuation coefficient $(K(\lambda))$ that changes seasonally in the euphotic layer. While the spectral distributions of downward Irradiance$(E_d)$ for the wave length of 470nm increase with depth, those of upward irradiance $(E_u)$ for the wave length range between 410nm and 490nm are constant, because the study area is covered with the blue and clear oceanic deep waters. The vertical attenuation coefficients of downward irradiance $(K_d)$ and upward irradiance $(K_u)$ have low values between 0.02 and $0.06m^{-1}$ due to the low absorption and scattering by the photosynthetic pigment of phytoplankton. Therefore this zone has the characteristics of the case 1 waters with low concentrations of photosynthetic pigment, and can be classifed into IB.

• Korean Journal of Oriental Medicine
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• v.16 no.2
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• pp.65-73
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• 2010

This study is to discuss the content of Posangkimun on the whole and to report the understanding of Seokgok Lee Gyujoon on western civilization. Through the overall analysis of Posangkimun, it is found the following facts: 1. Posangkimun aroused interest of academic circles as it covered theories of western civilization. Most of the introduction to western civilization contained in the book is related to astronomy and geography. Seokgok criticized all the western theories on revolution of the earth, astronomy, continents and oceans on the ground that these theories were not congruous with the teaching of the Oriental sages. 2. Seokgok found the reasons why the West had led the East from 'nationalism' of the West. The nationalism mentioned here were more similar to 'democracy' in modern sense, or rather 'democratism'. What is specially noteworthy is that he did not find the reasons of western advancement from the spiritual issues not from the machine civilization. In this way, Seokgok could avoid the fallacy of throwing away traditional ideas to concentrate in western machine civilization. 3. The content of Posangkimun shows that Seokgok was a person with a very conservative view. Notwithstanding his inclination, he had good knowledge about western theories, most of which were gathered from newspapers and magazines at that time. It means that newspapers and magazines should be treated with more importance when studying Korean intellectuals in late Joseon period or during the time of Japanese forced occupation.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.42 no.4
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• pp.203-209
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• 2006

This paper described the experimental squid jigging fishery conducted by a commercial fishing vessel in the Northwest Atlantic Ocean from August to October 2005. Author carried out experimental jiggings of 65 times during 57 days by three type of jigs which were pick jig, soft jig and soft luminous jig. The total catch, effort/day and catches/line-day of northern shortfin squid (Illex illecebrosus) were 12,726kg, 35 auto jigging machine and 3.5kg, respectively. Higher CUPE was observed in September, August and October. Catch ratio of pick jig was higher by 57-86% than those of soft jig and soft luminous jig. Higher catch was recorded at the $42^{\circ}55'N,\;62^{\circ}10'W$ with surface temperature ranging $18-21^{\circ}C$. The range of the dorsal mantle length was from 13.5cm to 23.0cm with average 17.2cm for female and from 13.0cm to 20.0cm with average 17.0cm for male. Sex ratio showed 55.4% of female.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.53 no.2
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• pp.181-190
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• 2020

This study was conducted to estimate the optimum dietary DHA oil level and replacement level of enzyme treated fish meal (EFM) with sardine fish meal for juvenile Atlantic bluefin tuna Thunnus thynnus. Four diets were used: 1) EFM75 in which 75% EFM and 4% DHA oil were applied, 2) EFM60, with 60% EFM and 15% sardine fish meal, 3) DHA2 with 2% of DHA oil, and 4) SL as a raw fish feed. In a feeding trial, juvenile bluefin tuna (body weight 30.1 g) were randomly stocked into four experimental tanks (69 tones) and fed the experimental diets for 13 days. Fish weight gain was higher in the EFM75 and SL groups than in the DHA2 and EFM60 groups. The feed conversion ratio was lower in the EFM75 and DHA2 groups than in the EFM60 and SL groups. Survival was higher in fish fed the formulated diet groups (EFM75, EFM60 and DHA2) than in fish fed SL. This study clearly indicates that up to 10% dietary sardine fish meal can be used in juvenile T. thynnus diets, with an optimum dietary DHA oil level of approximately 3%.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.27 no.2
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• pp.183-192
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• 1994

Spatial distribution patterns of Antarctic krill, Euphausia superba in the Atlantic Ocean sector were seasonally divided into three or four regions; South George Island, Laurie/Coronation Islands and Livingston/King George Islands. Antarctic krill were caught from the surface to about 150 m in depth. The vertical distribution of catch per hour (CPUE) did not show much differences between the 10 m layers, but there were gradually poorer CPUEs as trawl depth increased. It was estimated from relationship between water temperature and CPUE that the Antarctic krill abundance was maximal at water temperatures of $0.8{\sim}1.0^{\circ}C$. The length compositions of Antarctic krill showed that female fish were, on an average, significantly larger than males. Relationship between carapace length and body length, and body length-body weight relationship were well fitted. Sex ratio was $60.3\%$ for male and $39.7\%$ for female with significant difference at the $5\%$ level.