• Journal of the Society of Naval Architects of Korea
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• 제53권1호
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• pp.1-9
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• 2016

It is important to research and understand the physical phenomenon around a semi-submersible offshore structure on waves and currents because the wave run-up and load occurs owing to the waves and currents. In this study, the numerical simulations are performed about flow around a fixed semi-submersible offshore structure. The Modified Marker-density method is adopted in the present computation procedure, this method is one of the various methods to define the free-surface. The present computation results are compared with existing experimental and numerical simulation(VOF method) results. And, the computation results are relatively coincident with the existing results of model test and numerical simulation by VOF method.

• International Journal of Industrial Entomology and Biomaterials
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• 제21권2호
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• pp.151-155
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• 2010

Protein disulfide isomerase (PDI) catalyzes the oxidation of disulfides and the isomerizatiob of incorrect disulfides in new polypeptides during folding in the oxidizing environment of the endoplasmic reticulum (ER). To increase recombinant protein hSCF (human stem cell factor) production, we have developed expression system using the Bombyx mori PDI (bPDI) as a fusion partner. bPDI gene fusion was found to improve the production of recombinant hSCFs. Thus, we conclude that bPDI gene fusion will be very useful for the large-scale production of biologically active recombinant proteins.

• International Journal of Industrial Entomology and Biomaterials
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• 제21권2호
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• pp.169-174
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• 2010

Hydrolysate silk fibroin (HSF) is a fibrous protein composed of parallel $\beta$-structures and is made from pure silk elements including 18 amino acids, with glycine, alanine, and serine comprising of over 80% of the amino acids. Numerous studies have documented a range of effects of HSF, including moisturizing, antioxidant activity, nervous system disorders, and many more. We investigated whether HSF has anti-obesity effects in vitro. The effects of HSF inhibition on lipid accumulation and acceleration of lipid degradation in 3T3-L1 cells were studied. Treatment of 3T3-L1 cells with HSF caused significant inhibition of cell viability, an increase in glycerol release, and a decreased in adipocyte differentiation. Moreover HSF stimulated downregulated of adipogenic enzyme expressions (PPAR${\gamma}$ and C/EBP${\alpha}$) and up-regulated of fatty oxidation enzyme expressions (CPT-1 and UCP-2). Based on these results, hydrolysate silk fibroin can be suggested as a potential therapeutic substance as part of a prevention or treatment strategy for obesity.

• Journal of Surface Science and Engineering
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• 제49권5호
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• pp.408-415
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• 2016

The offshore structures exposed to harsh corrosive such as the marine environment is essential for the quality management technique throughout the life cycle of initial design, construction and operation. Also, it should satisfy the design life and ensure the safety of the substructure with optimization of design process. This study focused on optimization of design condition for corrosion protection of wind turbine structure and computational analyzing was performed to evaluate the performance of corrosion protection with utilizing practical experimental data. We expect this analytical study contribute to improve the corrosion maintenance stability and economical efficiency of designing wind turbine structures. As a result, the design of cathodic protection system using sacrificial anodes required accurate identification of current density in order to meet the long term design life, which can be seen that a change of structure surface's coating breakdown factor is one of the key influencing factors.

• Structural Engineering and Mechanics
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• 제50권1호
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• pp.53-71
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• 2014

A semi-analytical method is developed to consider free vibrations of a functionally graded elastic plate resting on Winkler elastic foundation and in contact with a quiescent fluid. Material properties are assumed to be graded distribution along the thickness direction according to a power-law in terms of the volume fractions of the constituents. The fluid is considered to be incompressible and inviscid. In the analysis, the effect of an in-plane force in the plate due to the weight of the fluid is taken into account. By satisfying the compatibility conditions along the interface of fluid and plate, the fluid-structure interaction is taken into account and natural frequencies and mode shapes of the coupled system are acquired by employing energy methods. The results obtained from the present approach are verified by those from a finite element analysis. Besides, the effects of volume fractions of functionally graded materials, Winkler foundation stiffness and in-plane forces on the dynamic of plate are elucidated.

• Fisheries and Aquatic Sciences
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• 제21권3호
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• pp.12.1-12.15
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• 2018

A preliminary investigation of length-weight relationship, condition factor and reproductive ecology of African pike fish, Hepsetus odoe, was conducted between June to August 2010 in Lake Eleiyele. A total of 90 samples of the fish species were caught by fishermen using gill nets. The results obtained showed that fish species had isometric growth pattern (contrary to negative allometry expected) with the growth exponent, b value of 2.64, that is not statistically different from 3 and with high statistical power of 0.866 when tested. The mean condition factor, K, was found to be 2.6, indicating that the fish species were in good condition in the study area. For reproductive biology, mean fecundity and gonadosomatic index were found to be 1349 eggs and 3.53% respectively. This study was necessary to fill the knowledge gap and provide information for management and conservation of the investigated species in the lake system. This study recommended that further research needs to be conducted because the sampling was carried out in the rainy season period and within a quarter of a year.

• Development and Reproduction
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• 제23권3호
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• pp.231-238
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• 2019

Interleukin-8 (IL-8) is an inflammatory cytokine that plays an important role in the inflammatory response through the activation of neutrophil cells. The expression of IL-8 was investigated in early developmental stages of the olive flounder and in tissues of 8-month-old individuals. The expression of IL-8 increased after the initiation of the immune system rather than at the early stage of development, and high expression was observed in the gills and spleen, the organs associated with immunity and metabolism. In addition, IL-8 expression after infection by viral hemorrhagic septicemia virus significantly increased in the fin, gill, muscles, and spleen. These results suggest that IL-8 is closely related to inflammation and immune regulation in the immune response of the olive flounder and may be used as a basis for studies on the immune systems of other fish.

• Journal of Species Research
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• 제11권3호
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• pp.169-173
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• 2022

Three species belonging to the genus Trapania Pruvot-Fol, 1931 are redescribed from Korea in this paper: Trapania euryeia Gosliner & Fahey, 2008, T. japonica (Baba, 1935), and T. toddi Rudman, 1987. Among these species, T. japonica is newly added to Korean fauna. The genus Trapania is characterized by a pair of extra-rhinophoral appendages on each side of the head, tentacular foot corners, a pair of extra-branchial appendages present around the gill, radula formula N×1.0.1. and consists of denticulated teeth, triaulic reproductive system, and minute spines on the armed penis. Herein, synonyms of the genus Trapania are summarized through a detailed literature review and the diagnostic characters of the genus Trapania are provided. Three species of the genus Trapania from Korea are distinguished from each other based on the color of extra-rhinoporal appendages and extra-branchial appendages, ground color, and distribution range of the brown markings on the dorsal surface. A taxonomic key to the genus Trapania in Korea is provided. In addition, the morphological characteristics of three trapanian nudibranchs in Korea are described and detailed photos of living animal are provided.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• 제34권3호
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• pp.274-282
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• 1998

This study deals with sinking resistance for purse seine, in the case of different d/l, ratio of twine diameter and leg length. Experiments carried out on the six types simplified reduced model seines which were made of knotless netting. The nettings were woven in different leg length 4.3, 5.0, 5.5, 6.0, 6.6 and 7.7mm of polyester 28 tex two threads two -ply twine, and each of the seines were named I, II, III, IV, V and Ⅵ seine. Dimension of seine models were 450cm for corkline and 85cm for seine depth, each seines rigged up 160g of float for a floatline and 50g (underwater weight) of lead for a leadline. Experiments were measured in the observation channel of a flume tank at the static conditions Sinking motion was recorded by the two sets TV-camera for VTR which were placed in top and side of the model seine, and reading coordinate carried out by the video digitization system. An analysis were calculated out by simultaneous differential equations for numerical method by Runge - Kutta - Gill sub - routine. The results obtained were as follows: 1. Average sinking speed of seine of seine margin was fastest for Ⅵ seine followed by V, IV, III, II and I seines. 2. The coefficient of resistance for a seine wall was depended upon the ratio of d/l : KD =0.081 (d/l )-0.5 3. The coefficient of resistance for netting bundle was not depended upon the ratio of d/l :CR = 0.91 (), d : Twine diameter, l : Leg length, : Density of netting materals, $\omega$ : Density of water

• Korean Journal of Fisheries and Aquatic Sciences
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• 제47권6호
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• pp.1037-1054
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• 2014

In this study, the status of coastal fisheries was examined based on the catch and number of fishing vessels of coastal fisheries in Korea. Comparing the status on coastal fisheries of the East Sea, Yellow Sea and South Sea in Korea, scientific evidence was made for fisheries management on coastal fisheries based on characteristics of each sea area. From 1990 to 2011, the catch of coastal fisheries in Korean waters ranged from 150,000 mt to 230,000 mt, with an average of 190,000 mt, and it accounted for 15% in average of total catch fished in adjacent waters of Korea. In order of catch by coastal fisheries, gillnet (36.7%) was the primary fishery, followed by coastal complex (24.7%), stow net (18.3%), trap (12.9%), lift net (3.9%), purse seine (3.0%) and beam trawl (0.4%) fisheries. In order of catch by species, anchovy (15.0%) had the largest proportion of total catch, followed by common squid (10.3%), akiami paste shrimp (5.2%), blue crab (3.9%) and octopus (3.7%). Of the average catch by sea area from 1990 to 2011, Yellow Sea, South Sea and East Sea were 37.4%, 34.6% and 28.0%, respectively. Since 2000s, however, the average catch of South Sea has accounted for the largest proportion. The number of permitted fishing vessels involved in 8 coastal fisheries was 55,336 vessels in average from 1997 to 2011. The number of vessels was about 47,000 vessels in 1997, and increased to 61,300 vessels until 2000, then has decreased to 44,000 vessels operating in 2011. In order of the number of permitted fishing vessels by fisheries, complex (52.4%) took the first place, followed by gillnet (31.5%), trap (13.4%), stow net (0.8%), beam trawl (0.8%), purse seine (0.6%), lift net (0.4%) and seine net (0.0%). In order of the number of permitted fishing vessels by sea area, South Sea (29,994 vessels) took the first place, followed by Yellow Sea (18,185 vessels) and East Sea (7,158 vessels). In order of the catch per unit effort (CPUE, mt/vessels) which was analyzed using catch and number of vessels in average by fishery, stow net is the highest followed by lift net, trap, purse seine, gill net, beam trawl and complex fisheries. In particular, the CPUE of complex and gill net fisheries, which accounted for the largest number of vessels were 4.0 mt/vessels and 1.6 mt/vessels, respectively. Since those are too low relative to other fisheries, it was judged to need systematical management on both fisheries.