• Journal of Fisheries and Marine Sciences Education
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• v.23 no.3
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• pp.361-373
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• 2011

In line with post-1970s industrialization, the manpower shortage in fishing villages has been fueled by rapid desertion; young adults and middle-aged people have tended to avoid fishing by migrating to cities, driving the emergence of a national issue in terms of securing fisheries management succession. For the fisheries industry to maintain competitiveness, we need to cultivate young adults and middle-aged people to be leaders of the domestic fishing industry through promoting inspiration for the fishing industry, teaching fisheries expert knowledge, and fostering the ability to promote business. In addition to safe supply of marine products through continued fisheries operation, securing young and skilful workers is essential in order to promote balance development of domestic industries, including job creation. The study therefore seeks to provide measures to foster specialists in order to enable the transfer of management through an opinion survey of fishermen. To cultivate specialists for enabling the transfer of management, the following solution should be promoted at the state level. First, to support the introduction of young and talented workers to the fisheries industry through transfer of management, Second, in order to enable the transfer of management, change is required first in the fisheries industry for it to become a value-added industry. Third, despite fisheries being a composite industry that is syncretized to tertiary industries from primary industries, the fisheries industry is still recognized as a labor intensive industry, which reflects the current status of fisheries education.

• Corrosion Science and Technology
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• v.11 no.6
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• pp.263-269
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• 2012

Copper alloys are commonly applied to ship's propellers, pumps and valves which are serviced in seawater due to their good castability and corrosion resistance. In the environment of high flow velocity, however, erosion damage predominates over corrosion damage. In particular, the cavitation in seawater environment accelerates surface damage to copper alloys, resulting in degradation of products and economic losses and also threatening safety. The surface was coated with WC-27NiCr by high velocity oxygen fuel(HVOF) spraying technique to attain durability and cavitation resistance of copper alloys under high velocity/pressure flow. The cavitation test was performed for the WC-27NiCr coating deposited by HVOF in seawater at the amplitude of $30{\mu}m$ with seawater temperature. The cavitation at $15^{\circ}C$ caused exfoliation of the coating layer in 17.5 hours while that of $25^{\circ}C$ caused the exfoliation in 12.5 hours. When the temperature of seawater was elevated to $25^{\circ}C$ from $15^{\circ}C$, more damage was induced by over 160%. Although WC-27NiCr has good durability, corrosion resistance and eletrochemical stability, the cavitation damage rate of the coating layer could remarkably increase at the elevated temperatures under cavitation environments.

• Corrosion Science and Technology
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• v.19 no.2
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• pp.100-107
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• 2020

The demand for powder-coated steel used in the marine industry is increasing owing to their superior corrosion resistance. However, the powder coatings used in commercial products can deteriorate easily by the penetration of brine. In an attempt to suppress brine penetration into the powder coating and significantly increase the corrosion resistance, three types of oxide particles were added to the coating. Electrochemical impedance spectroscopy tests in 3.5% NaCl solution were performed to evaluate the corrosion behaviors of the powder coating with oxide particles. The results showed that the addition of SiO₂ particles to a powder coating severely decreased the corrosion resistance due to the easy detachment of agglomerated SiO₂ particles with a coarse size from the coating layer. In contrast, the TiO₂ and SnO₂-added coatings showed better corrosion resistance, and the TiO₂-added coating performed best in the test conducted at room temperature. However, conflicting results were obtained from tests conducted at a higher temperature, which may be attributed to the effective suppression of brine penetration by the fine SnO₂ particles uniformly distributed in the coating.

• Korean Journal of Microbiology
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• v.46 no.3
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• pp.255-261
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• 2010

The bacterial community structure associated with two marine sponges, Hyrtios sp. 604 and Callyspongia sp. 612 collected from the South Pacific Ocean were analyzed by 16S rDNA-denaturing gradient gel electrophoresis (DGGE). The phylogenetic analysis showed that the bacterial community associated with Hyrtios sp. 604 contained diverse bacterial groups such as Chloroflexi, Firmicutes, Cyanobacteria, Alphaproteobacteria, Gammaproteobacteria, Actinobacteria, and Acidobacteria. Callyspongia sp. 612 harbored Chloroflexi, Cyanobacteria, Alphaproteobacteria, and Gammaproteobacteria. Hyrtios sp. 604 belonging to genus Hyrtios known to produce natural products showed greater bacterial diversity than Callyspongia sp. 612. Phylum Actinobacteria was shown to be one of dominant bacterial groups in Hyrtios sp. 604. Although the same phyla of bacteria were found in both sponge species, the spongeassociated predominant bacterial groups differed between the two sponges with different chemical characteristics from the same geographical location. Uncultured bacteria represented over 90% of the bacteria diversity present in all bacterial communities of the sponges.

• Journal of the Korean Chemical Society
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• v.6 no.1
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• pp.25-28
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• 1962

The colorimetric estimation, by dithiol method, of the solubility of tin dissolved from the container the tin plate in some canned marine foods has been made on 200 cans of sample on the market. Some of them contained more than 150 ppm of Sn concentration were as follows; (1) ca. 50% of squid can, (2)ca. 30% of mackerel can, (3) ca. of saury can, (4) naught of crab, whale, clam(Japanese hard clams), fish meat ball, and Turbo cornutus one. (1) It had the tendency of increasing Sn concentration according to lowering or arising the value of pH. (2) No significant difference in Sn concentration was caused by the variation of the sort of tinning as H-D or E-T. (3) The longer the period of the storage the higher Sn concentration was found, and the concentration more than 150 ppm of Sn was generally found among the cans stored more than twelve months. (4) The concentration of Sn in the liquid was higher than in solid portion, and most of dissolved Sn was distributed in the liquid portion.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2017.05a
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• pp.673-676
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• 2017

The Offshore drilling system of domestic drilling systems (drill rigs, drill ship) in Korea is dependent on full imports and the monopolistic situation of a few foreign large corporations is intensifying. In addition, most of domestic technology development tries to develop single product oriented products until now, but it is necessary to develop monitoring control system for package unit commercialization by approaching package development method. Therefore, we will develop a control monitoring system that can integrate the single equipment of the mud system developed previously.

• Journal of Life Science
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• v.16 no.1
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• pp.88-94
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• 2006

The random amplified polymorphic DNA (RAPD) technique was investigated as a potential tool for the origin identification of olive flounder (Paralichthys olivaceus) and redlip croaker (Pseudosciaena polyactis). Olive flounder specimens were collected from North Korea and several locations of South Korea (Jumunjin, Tongyoung and Geoje). Fishes obtained from Tongyeong and Geoje were cultured products. Redlip croaker specimens were collected from South Korea and China. Consistent and distinct diagnostic bands were easily identified in the RAPD patterns of the olive flounder specimens. Although consistent diagnostic bands rarely appeared in the RAPD pattern of redlip croaker specimens because of their genetic heterogeneity, we were able to find potential diagnostic bands in the average RAPD pattern of each origin.

• Journal of Life Science
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• v.13 no.6
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• pp.799-804
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• 2003

In order to verify the occurrence of an estrogenic compound in natural products, the estrogenic activity was measured using an in vitro detection system. For this system, human breast cancer cell line MCF7 was transfected using an estrogen responsive CAT reporter plasmid. Estrogenic activities of photosynthetic algae spirulina and sea lettuce were evaluated using this system. Estrogenic activities of a $500\mug/ml\; and\; 50 \mug/ml$ ethanol extracts of spirulina were as much as that of $10^{-8}$M standard solution (17$\beta$-estradiol) and activity of $5\mug/ml$ ethanol extract of spirulina was as much as that of $10^{-10}$ M standard solution. However, no significant estrogenic activity was observed using sea lettuce extract. Estrogenic activities of marine animals, such as star fish and shrimp, were also evaluated using this system, however, no significant estrogenic activity was observed in these extracts. In this result, it is confirmed that spirulina extract possesses estrogenic compound.

• Journal of Surface Science and Engineering
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• v.51 no.4
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• pp.224-230
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• 2018

In this study, Mg films were prepared on hot dip aluminized steel (HDA) by using a sputtering method as a high corrosion resistance coating. The corrosion resistance of the Mg films was improved by controlling the morphology and the crystal structure of films by adjusting the Ar gas pressure during the coating process. Anodic polarization measurement results confirm that the corrosion resistance of the Mg films was affected by surface morphology and crystal structure. The corrosion resistance of the Mg coated HDA specimen increased with decreasing crystal size of the Mg coating and it was also improved by forming a film with denser morphology. The crystal structure oriented at Mg(101) plane showed the best corrosion resistance among crystal planes of the Mg metals, which is attributed to its relatively low surface energy. Neutral salt spray test confirmed that corrosion resistance of HDA can be greatly improved by Mg coating, which is superior to that of HDG (hot dip galvanized steel). The reason for the improvement of the corrosion resistance of Mg films on hot dip aluminized steel was due to the barrier effect by the Mg corrosion products formed by the corrosion of the Mg coating layer.

• Journal of Korea Port Economic Association
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• v.25 no.3
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• pp.303-320
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• 2009

Korea has achieved a remarkable growth by pursuing externally-oriented growth policy since 1960s. That is, we imported raw materials and spare parts, manufactured them into products and exported them, which led to successful economic development. Therefore, our marine business has played an important roles as one of key industries. The development of marine business has contributed to efficient distribution and cost reduction in addition to production of added value and creation of employment creation, which improved external competitive power. In spite of economic importance of marine business, national perception on it is in general low and its developmental conditions are considerably poor. Therefore, this study aims to speculate the effect of Port-related business on regional economy using regional input-output tables.