• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.24 no.3
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• pp.422-428
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• 2019

Fish killing dinoflagellate Cochlodinium polykrikoides has been separated into four genetically differentiated subpopulations globally based on large-subunit (LSU) ribosomal RNA gene, and two subpopulations have been found in the South Sea, Korea. In this study, distributions of the East Asia and Philippines ribotypes were surveyed in the South Sea for 3 years (2014~2016) using quantitative real-time PCR (qPCR). The East Asia ribotype was detected in all sampling stations of the South Sea (Tongyeong~Wando) by 40~100% positives for 2014~2016, whereas the Philippines ribotype was detected in some areas of Tongyeong~Goheung by 1~2% positives for only 2016 when the Tsushima Warm Current (TWC) was particularly strengthened. These results indicate that the East Asia ribotype is the dominant subpopulation in the South Sea, also some of C. polykrikoides swimming cells might be transported from offshore to the South Sea via TWC.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.14 no.1
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• pp.63-68
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• 2009

Among various microscopic organisms producing photobiological hydrogen, cyanobacteria have long been recognized as the promising biological agents for hydrogen economy in 21 century. For photobiological production of hydrogen energy, marine unicellular $N_2$-fixing cyanobacteria have been evaluated as an ideal subgroup of Cyanophyceae. To develope the hydrogen production technology using unicellular $N_2$-fixing cyanobacteria, 3 important factors are pre-requisite: 1) isolation of the best strain from marine natural environment, 2) exploration on the strain-specific optimal conditions for the photobiological hydrogen production, and finally 3) application of the molecular genetic tools to improve the natural ability of the strain to produce hydrogen. Here we reviewed the recent research & development to commercialize photobiological hydrogen production technology, and suggest that intensive R&D during next 10-15 years should be imperative for the future Korean initiatives in the field of the photobiological hydrogen production technology using photosynthetic marine unicellular cyanobacterial strains.

• Journal of the Korean Society of Marine Environment & Safety
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• v.25 no.6
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• pp.658-665
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• 2019

Among the renewable energy resources, wind power is growing rapidly in terms of technological development and market share. Recently, onshore wind farm have been affected by limitations of terrestrial space and environmental problems. Consequently, installation sites have been moved to the sea, and the development of floating offshore wind farms that are installed at deep waters with more abundant wind conditions is actively underway. In the context of maritime traffic, the optimal site of offshore wind farms is required to minimize the interference between ships and wind turbines and to reduce the probability of accidents. In this study, genetic algorithm based AIS(Automatic Indentification System) data composed of genes and chromosomes has been used. The optimal site of floating offshore wind farm was selected by using 80 genes and by evaluating the fitness of genetic algorithm. Further, the final site was selected by aggregating the seasonal optimal site. During analysis, 11 optimal site were found, and it was verified that the final site selected usng the genetic algorithm was viable from the perspective of maritime traffic.

• The Journal of the Acoustical Society of Korea
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• v.22 no.8
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• pp.645-651
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• 2003

This paper presents a revised beamforming inversion method for ocean acoustic tomography. In the proposed inversion method, the relation between group velocity and phase velocity that are the characteristics of the waveguide is used for the inversion of perturbed sound speed profile. The group velocity and phase velocity can be expressed as a function of the travel time and arrival angle of the received signals that are analyzed by the beamforming signal processing. This paper illustrates the simulated results of inversion for the fluctuated sound speed profile of the East Korea Sea and we found the applicability of revised beamforming inversion method to range independent ocean.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2009.10a
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• pp.453-456
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• 2009

In this paper, a Microstrip antenna for wireless LAN is designed in HyperLAN 5GHz. The IEEE 802.11a have allocated HyperLAN band. We proposed CPW-fed antenna structure for compact antenna. This structure shows that a ground plane and a patch plane are existed at one layer. The proposed antenna is designed on FR-4 substrate with a relative dielectric constant 4.3, thickness of 1.5mm and tangent loss 0.02. The designed antenna shows that VSWR is below 2 and has good return loss below -10dB over the 5.725~5.825GHz bandwidth with HyperLAN.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.22 no.2
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• pp.362-368
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• 2018

Making proper judgements in urgent situations facing a submarine at the sea is very critical. This is because the commander's misjudgments could drive the entire ally to destruction in a moment. In order to generate appropriate tactics on behalf of the human commander and to analyze the effectiveness in such emergency situations, studies using intelligent agents and genetic algorithms have been conducted. In this study, inference engine based intelligent agent is adopted to each warship and submarine to generate optimal tactics on the variable environment with genetic algorithms. And we analyze the risk of the alliance according to the performance of the enemy submarine through a simple simulation and generate appropriate tactics using the genetic algorithm. Also generated tactics are evaluated and the results are analyzed to figure out why such results are formed.

• Korean Journal of Ichthyology
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• v.33 no.4
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• pp.205-216
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• 2021

Phylogenetic reconstruction based on one locus or a few loci can be misleading due to gene-tree/species-tree discordance. Species delimitation and intraspecific studies also often suffered from low resolution because of insufficient statistic power when few loci were used. Exon capture method is one of the most efficient way to collect genome-scale data, which can significantly augment studies that aimed to investigate patterns and histories of organisms at both intraspecific and high level. Here, I showed the advancement of shifting from single-gene method to genomic approach and the benefit of applying exon capture method comparing to alternative genomic techniques. Then, I explained the principle of exon capture method as well as providing detailed recommendations for applying this method. Finally, I demonstrated exon capture method using two applications and discussed future perspectives of this technology.

• Korean Journal of Microbiology
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• v.54 no.4
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• pp.480-482
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• 2018

The draft genome sequencing for Zhongshania marina $DSW25-10^T$, isolated from deep seawater of East Sea in Korea, was performed using Illumina HiSeq platform. As a result, the draft genome was comprised of a total length of approximately 4.08 Mbp with G + C content of 49.0%, and included a total of 3,702 protein-coding genes, 3 rRNA genes, 39 tRNA genes, 4 non-coding RNA genes, and 36 pseudogenes. In addition, the metabolic pathways of aliphatic and aromatic compounds were identified. In light of these metabolic pathways, Zhongshania marina $DSW25-10^T$ is expected to be a useful bioremediation resource.

• Journal of Scientific & Technological Knowledge Infrastructure
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• s.10
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• pp.26-49
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• 2002

생물다양성은 육상 생태계, 해양과 기타 수생 생태계와 이들의 복합 생태계를 포함하는 모든 원천에서 발생한 생물체의 다양성을 말하며, 종내.종간 및 생태계의 다양성을 포함한다. 즉, 생물다양성이란 생물종(Species)의 다양성, 생물이 서식하는 생태계(Ecosystem)의 다양성, 생물이 지닌 유전자(Gene)의 다양성을 총체적으로 지칭하는 말이다. 종다양성(Species diversity)은 한 지역내의 종의 다양성 정도를 말하는 것으로서 분류학적 다양성을 지칭하며, 생태계 다양성(Ecosystem diversity)은 한 생태계에 속하는 모든 생물과 무생물의 상호작용에 관한 다양성을 말한다. 또한 유전적 다양성(Genetic diversity)은 종내의 유전자 변이를 말하는 것으로 같은 종내의 여러 집단들을 의미하거나 한 집단내 개체들 사이의 유전적 변이를 의미한다.