• Journal of Ocean Engineering and Technology
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• v.27 no.6
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• pp.7-15
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• 2013

Eco-friendly and sustainable seaweed biomass energy have been under the spotlight as the future of renewable energy. However, seaweed culture is primarily conducted inshore, with the research on offshore culture still in an early stage. For massive biomass production, a systematic engineering approach is required to devise offshore seaweed culture facilities rather than the conventional empirical ones. To establish the fundamental behavior of seaweed culture facilities, the dynamic characteristics of a seaweed culture facility were analyzed in the study. For this purpose, numerical analyses of the seaweed culture facility (a frame type) were carried out by using the hydrodynamic simulation program ANSYS-AQWA. For the analysis, environmental loads were considered using the wave spectra and co-linear current; mooring variables were selected as parameters; and time domain analyses were carried out to acquire the time series responses and eventually the dynamic characteristics. Finally, the mooring performance was evaluated. It was found that the motion could be controlled by adjusting the buoyancy and mooring slope.

• Journal of the Korean Society of Marine Environment & Safety
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• v.21 no.3
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• pp.283-289
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• 2015

This paper provides a study on the application and proposals of safety culture, new public management and social amplification of risk framework via ship accidents in Korea. This document analyzes what are the concept of safety culture, new public management as well as social amplification and risk framework and describes how 3 issues act, harmonize, interrelate through M/V Sewol accident. Korean government is needed to apply social amplification of risk framework to the in order to promote the safety culture in the maritime administration. Hence, this paper proposes safety framework in order to prevent and resolve future unexpected accident especially for maritime field.

• Korean journal of food and cookery science
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• v.26 no.4
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• pp.434-440
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• 2010

This study was conducted among university students living in the Daegu-Gyeongbuk region to determine the perception, Preference, and improved consciousness of Gyeongbuk local foods classified by the Yugyo, Silla, Ocean, and Gaya cultures. In the Andong area, subjects demonstrated outstanding, high rates of perception of and preference for local foods. The perception of and preference for foods from the Yugyo and Silla cultures were relatively high compared to those of others. The degree of perception of Gwamegi foods was high, but the degree of preference was rather low. It is believed that establishing new counterplans is necessary to obtain higincrease preference for foods from the Ocean culture. Sigeumjang foods of the Ocean culture showed alow degree of both perception and preference. The analysis showed that there was a discrepancy between the perception of and preference for foods in the Gaya culture. To improve the relationship between awareness of and preference for foods in the same culture we determined that menu strategy, development strategy and sales strategy were important factors. The results of the survey investigating the correlation between improved awareness of and perception of foods showed menu strategy and development strategy had meaningful effects. According to the survey, the factors that influenced choices of foods local to Yugyo were classified into categores-: menu strategy, development strategy, product strategy, and sales strategy.

• ALGAE
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• v.38 no.4
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• pp.283-294
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• 2023

Previous research indicated that free-living sporangial filament keep hollow morph under high-culture density and form bipartite cells under low-culture density, while the following conchospore release was inhibited by high light. Here, we further explored the molecular bases of these affects caused by light and culture density using a transcriptome analysis. Many differentially expressed genes (DEGs) related to carbon dioxide concentration and fixation, photosynthesis, chlorophyll synthesis and nitrogen absorption were upregulated under high-light conditions compared with low-light conditions, indicating the molecular basis of rapid vegetative growth under the former. The stress response- and ion transport-related DEGs, as well as the gene encoding the vacuole formation-brefeldin A-inhibited guanine nucleotide exchange protein (BIG, py05721), were highly expressed under high-density conditions, indicating the molecular basis of the hollow morph of free-living sporangial filaments under high-culture density conditions. Additionally, the brefeldin A treatment indicated that the hollow morph was directly influenced by vacuole formation-related vesicle traffic. Others DEGs related to cell wall components, zinc-finger proteins, ASPO1527, cell cycle and cytoskeleton were highly expressed in the low density with low-light group, which might be related to the formation and release of conchospores. These results provide a deeper understanding of sporangial filaments in Neopyropia yezoensis and related species.

• Journal of Aquaculture
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• v.19 no.4
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• pp.242-246
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• 2006

Comparisons of growth and survival rate in different culture systems for juvenile abalone were determined in the West Coast of South Korea from June, 2000 to April, 2001. Daily growth rate reached at the maximum by $148.6{\pm}48.96\;{\mu}m/day$ with a stagnant system and at the minimum by $95.3{\pm}21.45\;{\mu}m/day$ with a sprinkler culture system. Survival rate of the juvenile abalone was significantly higher than that in sprinkler culture with a rotary culture (P<0.05). The highest survival rate was 50.0% in the rotary culture and 38.3% was observed in the stagnant culture system. The results from this study indicate that effective survival and growth rate could be predicted in the rotary culture system.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2012.06a
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• pp.125-126
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• 2012

Busan Metropolitan City is the 3rd Marine City, which has the largest Container port facility and logistic system in the world. However, Busan Citizen's maritime consciousness does not reach that level. This study figures out the problems, and suggests the revitalization of Ocean Education in Busan. This is for the revitalization of the reputation as a Marine City Busan, construction the hydrophil culture and propagation of ocean culture.

• ALGAE
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• v.33 no.1
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• pp.127-141
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• 2018

Low efficiency in microalgal biomass production was largely attributed to the low density of algal cell cultures. Though mutations that reduced the level of chlorophyll or pigment content increased efficiency of photon usage and thus the cell-culture density under high-illumination growth conditions (e.g., >$500{\mu}mol\;photon\;m^{-2}\;s^{-1}$), it was unclear whether algae could increase cell-culture density under low-illumination conditions (e.g., ${\sim}50{\mu}mol\;photon\;m^{-2}\;s^{-1}$). To address this question, we performed forward genetic screening in Chlamydomonas reinhardtii. A pool of >1,000 insertional mutants was constructed and subjected to continuous subcultures in shaking flasks under low-illumination conditions. Complexity of restriction fragment length polymorphism (RFLP) pattern in cultures indicated the degree of heterogeneity of mutant populations. We showed that the levels of RFLP complexity decreased when cycles of subculture increased, suggesting that cultures were gradually populated by high cell-culture density (HCD) strains. Analysis of the 3 isolated HCD mutants after 30 cycles of subcultures confirmed that their maximal biomass production was 50-100% higher than that of wild type under low-illumination. Furthermore, levels of chlorophyll content in HCD mutant strains were similar to that of wild type. Inverse polymerase chain reaction analysis identified the locus of insertion in two of three HCD strains. Molecular and transcriptomic analyses suggested that two HCD mutants were a result of the gain-of-function phenotype, both linking to the abnormality of mitochondrial functions. Taken together, our results demonstrate that HCD strains can be obtained through continuous subcultures under low illumination conditions.

• Journal of Marine Bioscience and Biotechnology
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• v.2 no.3
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• pp.174-186
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• 2007

Amphora coffeaeformis and Achnanthes longipes are commonly found as dominant benthic microalgae in Jeju coastal water throughout the year. In order to investigate pharmaceutical uses of these diatoms, each single species was isolated with micropipette under phase contrast microscope and subcultured with synthetic seawater media which was enriched with F/2 media, trace metal solution and $Na_2SiO_3$). Growth characteristics of these species were also determined with different combination of salinity, nutrients concentration and temperature. Thereafter, mass culture of each species was done based on the maximum growth condition. Biomass was collected after two weeks of mass culture and freeze dried for antioxidant study. The antioxidant properties of different fractions (n-hexane, chloroform and ethylacetate) obtained by solvent fractionation of 80% methanolic extract of two microalgae were investigated for free radical, reactive oxygen species scavenging (Super oxide, Hydrogen peroxide, Hydroxyl radical and Nitric oxide), metal chelating and lipid peroxidation inhibition activities. All fractions of A. longipes showed higher $DPPH^{\cdot}$ (free radical) scavenging activities (n-hexane: 89.0%, Chloroform: 76.0%, Ethylacetate: 66.0%, Methanol: 90.6% and aqueous residue: 63.0%). N-hexane fraction of A. longipes showed significantly higher activity (49.0%) on nitric-oxide. Ethylacetate fraction of A. longipes and aqueous residue of A. coffeaeformis exhibited 64.0% and 75.6% metal chelating activity which was higher than commercial antioxidants (${\alpha}$-tocopherol: 18.0% and BHT: 16.0%). The n-hexane fraction of A. coffeaeformis had 67.5% activity on $DPPH^{\cdot}$. Chloroform and n-hexane fractions of A. coffeaeformis exhibited 46.2% and 47.6% $H_2O_2$ scavenging effects which were closely similar to commercial antioxidants (${\alpha}$-tocopherol: 49.2% and BHT: 58.6%). Chloroform and ethylacetate fractions of A. longipes and fraction of n-hexane and chloroform of A. coffeaeformis showed better lipid peroxidation activities than ${\alpha}$-tocopherol. These data suggest that both organic and aqueous fractions have good antioxidative compounds with different antioxidant properties.

• Journal of Navigation and Port Research
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• v.36 no.6
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• pp.507-512
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• 2012

Korea is the 5th Maritime Power in the world, especially, Busan Metropolitan City is the 3rd Marine City, which has the largest Container port facility and logistic system in the world. However, Busan Citizen's maritime consciousness does not reach that level. This study points out the problems, which are insufficiency of linkage among maritime education institutes, uniformity of ocean education programs, incomplete ocean education system, inadequate management of ocean education programs and shortage of professional instructors. To solve these problems, it is necessary to develop the ocean education modules, establish the ocean education course and put into formal education course to maximize the education effectiveness. This is for the improvement of the reputation as a Marine City Busan, construction the hydrophil culture and propagation of ocean culture.

• Korean Journal of Environmental Biology
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• v.30 no.1
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• pp.71-76
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• 2012

Spills of $M/V$ Hebei Spirit on $7^{th}$ December 2007 caused a seriously damage to the ecosystem of Korean coast. Of these, microbial communities (i.e., attached benthic micro-algae) were reported to be sentive to the environmental change so it can be used for ecological risk assessment. Our experiment was designed to examine the ecological risk assessments for oil pollutant using benthic attached algal community on the artificial substrates of acrylic plates. Field monitoring in the culture system was conducted in Jangmok Bay. The abundances of attached micro-algae on artificial substrates gradually increased with increasing of sampling times. Among them, diatoms were the most important colonizer of coastal water, with the genera $Cylindrotheca$ and $Navicular$ most abundant. In particular, developed the culture system has correctly measured qualitative and quantitative abundance of attached micro-algae because same acrylic plates as artificial substrates were used. Thus, this culture system may be directly applied to the ecological risk experiments of microbial community structure from oil pollutants.