• Journal of architectural history
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• v.28 no.2
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• pp.7-18
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• 2019

The Chosun Dynasty established and implemented measures to prevent Japanese invasion into the southern coast. To this end, the number of naval vessels and the number of ships were increased, and a shipyard(船所) was constructed to protect the safety of the vessels. The shipyard is a port facility where military vessels are anchored and repaired, as well as public facilities that are needed for military training on public and land, as well as facilities for storing supplies and equipment needed for ships on land and defense at the port entrance. Despite being such an important facility for national defense, Shipyard has not been noticed. Studies have shown that the position of shipyard is divided into the riverside type and the riverbank type, which is due to the topographical features of Korea. The repair cycle of naval vessels, the carrying out of Yeonhun(prevent the water from decaying the part of the ship, a raw tree was burned to smoke) and the place of sea training also affected the construction of the Gul River(掘江). The space structure of shipyard is divided into port entry facilities for monitoring and controlling at the entrance to the harbor, border facilities for folding and repairing military vessels, and land facilities for holding land exercises and administrative work of military vessels and military equipment.

• Fisheries and Aquatic Sciences
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• v.24 no.6
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• pp.228-234
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• 2021

A single specimen (39.4 mm standard length) of Brachaluteres ulvarum, belonging to the family Monacanthidae has been recorded for the first time from Supseom, Jeju-do Island of southern Korea on 6 March 2021. This species was characterized by the presence of a small second dorsal spine present, the posterior end of pelvic without encasing scales, and numerous thin dark longitudinal lines on body. It was morphologically similar to the B. taylori, but distinguished by the ratio of the caudal peduncle to the head length (B. ulvarum, 2.5 to 3.7 times; B. taylori, 3.5 to 5.2 times). In addition, the former is well distinguished from the latter through mitochondrial cytochrome c oxidase subunit I (COI) sequences by genetic distances of range from 0.088 to 0.090. The new Korean name "Kko-ma-jwi-chi- sog" is proposed for the genus Brachaluteres, and "Kko-ma-jwi-chi" for the species B. ulvarum.

• Journal of Climate Change Research
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• v.34 no.16
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• pp.6565-6581
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• 2021

This study investigates the role of the background meridional moisture gradient (MMG) on the propagation of the Madden-Julian oscillation (MJO) across the Maritime Continent (MC) region. It is found that the interannual variability of the seasonal mean MMG over the southern MC area is associated with the meridional expansion and contraction of the moist area in the vicinity of the MC. Sea surface temperature anomalies associated with relatively high and low seasonal mean MMG exhibit patterns that resemble those of El Niño-Southern Oscillation. By contrasting the years with anomalously low and high MMG, we show that MJO propagation through the MC is enhanced (suppressed) in years with higher (lower) seasonal mean MMG, although the effect is less robust when MMG anomalies are weak. Column-integrated moisture budget analysis further shows that sufficiently large MMG anomalies affect MJO activity by modulating the meridional advection of the mean moisture via MJO wind anomalies. Our results suggest that the background moisture distribution has a strong control over the propagation characteristics of the MJO in the MC region.

• Journal of the Korean Society for Marine Environment & Energy
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• v.18 no.3
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• pp.143-156
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• 2015

In order to understand the dynamic characteristics of water column environments in the Western Pacific seamount area (approximately $150.2^{\circ}E$, $20^{\circ}N$), we investigated the water mass and the behavior of water column parameters such as dissolved oxygen, inorganic nutrients (N, P), and chlorophyll-a. Physico-chemical properties of water column were obtained by CTD system at the nine stations which were selected along the east-west and south-north direction around the seamount (OSM14-2) in October 2014. From the temperature-salinity diagram, the main water masses were separated into North Pacific Tropical Water and Thermocline Water in the surface layer, North Pacific Intermediate Water in the intermediate layer, and North Pacific Deep Water in the bottom layer, respectively. Oxygen minimum zone (OMZ, mean $O_2$ $73.26{\mu}M$), known as dysoxic condition ($O_2<90{\mu}M$), was distributed in the depth range of 700~1,200 m throughout the study area. Inorganic nutrients typified by nitrite + nitrate and phosphate showed the lowest concentration in the surface mixed layer and then gradually increased downward with representing the maximum concentration in the OMZ, with lower N:P ratio (13.7), indicating that the nitrogen is regarded as limiting factor for primary production. Vertical distribution of water column parameters along the east-west and south-north station line around the seamount showed the effect of bottom water inflowing at around 500 m deep in the western and southern region, and concentrations of water column parameters in the bottom layer (below 2,500 m deep) of the western and southern region were differently distributed comparing to those of the other side regions (eastern and northern). The value of Excess N calculated from Redfield ratio (N:P=16:1) represented the negative value throughout the study area, which indicated the nitrogen sink dominant environments, and relative higher value of Excess N observed in the bottom layer of western and southern region. These observations suggest that the topographic features of a seamount influence the circulation of bottom current and its effects play a significant role in determining the behavior of water column environmental parameters.

• Journal of Life Science
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• v.18 no.2
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• pp.284-286
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• 2008

Octopus minor (O. minor) is widely distributed along the coastal regions of Korea, but most of them are caught in southern waters which are associated with one of the important fisheries stock. At present, O. minor from China has been introduced to the fishery markets in Korea. Here, we attempt to discriminate their origin for Korea or China using molecular techniques. Based on the O. minor mitochondrial DNA sequence, we developed a PCR-based origin discrimination system. The assay specificity was assessed by testing four individuals of O. minor from Sangdong, China, as well as 20 additional O. minor from Namhae, Muan, Yeosu and Jindo, Korea. Only four isolates of O. minor originated from China tested as positive in our distinction system. All PCR-positive products yielded identical sequences from Chinese O. minor, whereas Korean O. minor appeared to be PCR amplification. This result suggested that the primers used in this study are O. minor species specific, especially originated from China. The detection system appeared to be positive results in the use of 0.1 ng of Chinese O. minor DNA as template, however, the Korean O. minor even using $1{\mu}g$ of DNA showed no amplification. Consequently, the assay provides a simple, rapid and accurate method for the detection of Chinese O. minor.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.44 no.3
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• pp.165-173
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• 2008

Sea experiment for this study was carried out to develop a Trawl Escapement Net(TEN) using net material to improve the survival rate of undersized fishes that escaped from trawls in the Korean southern sea in May and November, 2005. Three kinds of Trawl Escapement Net(TEN) were examined to increase the escapement rate for fishes escaped from the TEN, and total catches in the codend and cover-net were investigated. The main catch species in the experimental fishing trials using a V shape TEN(A type) in May were Korean pomfret(Pampus echinogaster), slimy(Leiognathus nuchalis), gizzard shad(Konosirus punctatus), white croaker(Pennahia argentata) and smelt(Sillago sihama). In the experimental fishing trials using a V shape TEN with a protector for undersized fishes(B type) and a panel shape TEN with a protector(C type) in November, the main catch species were horse mackerel(Trachurus japonicus), sea pike (Sphyraena japonica), large-head hairtail(Trichiurus lepturus), kammal thryssa(Thryssa kammalensis), white croaker(Pennahia argentata), butterfish(Psenopsis anomala) and red gurnard(Lepidotrigla microptera). Most of large-sized fish species like Korean pomfret and Spanish mackerel could not escape through the TEN in the B type and C type. Catches of horse mackerel were highest in the experimental fishing of November and escapement rates for most fish species including horse mackerel were higher in the C type compared with B type.

• Journal of Advanced Marine Engineering and Technology
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• v.35 no.4
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• pp.491-499
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• 2011

Starting with maritime DGPS base stations of Palmido, Ochongdo which have been operated since 1999, truly our nation has become the most powerful country possessed with total of 17 DGNSS base stations in the field of DGNSS operation infrastructure. This paper examines into the country's DGNSS services as measuring the service range of the maritime DGPS base stations in the domestic ferry lines which sections are from Jeju to Incheon, from Busan to Jeju, from Jeju to Nokdong, the propagation characteristics of the radio waves of 300 kHz bands on sea and land path. As a result of identifying the service range of the DGPS in the sea routes of the southern sea and the western sea, the measured results of the DGPS signals are confirmed more than 100 NM(recommended service range). It can be possible to practical use the position information, which is safe navigation and various marine traffic management systems. It will be useful an expansion of maritime DGPS reference station in the near future.

• Journal of the korean society of oceanography
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• v.39 no.1
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• pp.46-56
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• 2004

Spectral attenuation of light and upwelling radiance were measured in the western coast of Korea on board the R/V Inchon 888 of the Korean National Fisheries Research and Development Institute(NFRDI) during four seasons. The goal of these efforts was to determine the spatial and temporal distribution of the inherent and apparent optical properties of the water, and the factors that control their distribution. Our data indicate that while stratification of the water column, phytoplankton, and wind stress determined the vertical distribution of the optical parameters offshore, it was the tidal current and sediment type that controlled both the vertical and horizontal distribution in the coastal areas. These findings led to the development of a model that estimates the spectral attenuation of light with respect to depth and time for the Yellow Sea. The model integrates water leaving radiance from satellites, sediment types, current vectors, sigma-t, bathymetry, and in situ optical measurements in a learning algorithm capable of extracting optical properties with only knowledge of the environmental conditions of the Yellow Sea. The performance of the model decreases with increase in depth. The mean absolute percentage error (MAPE) of the model is 2% for the upper five meters, 8-10% between 6 and 50 meters, and 15% below 51 meters.

• Ocean and Polar Research
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• v.36 no.4
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• pp.373-381
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• 2014

Korea contract Mn-nodule field in the NE equatorial Pacific is composed of seven sectors with average water depths of 4,513-5,025 m. Of the various factors controlling the properties of Mn-nodule, it seems that water depth is likely connected to the chemical composition and occurrence of nodules. To test whether such an assumption held in each sector, we reviewed previous research data accumulated since 1994 for one of the northern sectors (hereafter KR1) where there are stark contrasts in water depth. High-resolution seabed mapping clearly separates a northern part (KR1N) from a deeper southern part (KR1S), cutting across in the middle of the KR1. In addition, significant volcanic activities forming numerous seamounts are distinctive especially in KR1N. In terms of nodule occurrence, manganese nodules in KR1S are comparatively larger (2-4 cm) with a discoidal shape, while those in KR1N are generally small (<2 cm) with poly-lobate and irregular shapes. Nodules in KR1N also have lower Co, Cu, Mn and Ni, and higher Fe contents. The spatial separation in nodule characteristics might be caused by volcanic activities in KR1N rather than water depth contrast. During the formation of the seamounts in KR1N, rock fragments and volcanic ashes as new nuclei of the nodules would have been continuously generated. As a result, the nodules could not grow larger than 2 cm and display the shapes of a newbie (i.e., irregular and poly-lobate shapes). Moreover, significant Fe supply from volcanic activities probably decreases the Mn/Fe ratio, which may lead to the KR1 nodules being misinterpreted as a hydrogenic in origin compared to other sectors where a high Mn/Fe ratio is present.

• Fisheries and Aquatic Sciences
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• v.11 no.1
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• pp.7-14
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• 2008

The sanitary quality of a shellfish-growing area in Kamak Bay, Korea, was assessed through a bacteriological examination of seawater and oysters from January 2004 to December 2006. From seawater samples collected at 28 stations, the range of geometric mean (GM) and the estimated 90th percentile for most-probable-number (MPN) values of fecal coliforms were <1.8-2.4 MPN/100 mL and 1.8-6.0 MPN/100 mL, respectively. The observed fecal coliform GM and the estimated 90th percentile did not exceed the fecal coliform water quality standards of 14 MPN/100 mL and 43 MPN/100 mL. Therefore, the bacteriological quality of seawater at this shellfish-growing area met the Korean Shellfish Sanitation Program (KSSP) criteria for a growing area used for export. The range of the fecal coliform GM and the estimated 90th percentile MPN values of oyster samples were 19.2-160 MPN/100 g and 20.2-166.9 MPN/100 g, respectively, and the range of the viable cell count was 30-1900 CFU/g. Thus, the fecal coliform value for the oysters and the viable cell count were less than the current shellfish quality standards of 230 MPN/100 g and 50,000 CFU/g, respectively. The bacteriological quality of the oysters complied with the criteria for domestic use and export of shellfish.