• Korean Journal of Medicinal Crop Science
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• v.14 no.6
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• pp.347-353
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• 2006

This study was conducted to evaluate the vegetation structure and ordination of the Peucedanum japonicum Thunb. community by the Phytosociological method, floristic composition table on east coast of South Korea. The vegetation of Peucedanum japonicum Thunb. community was classified into 2 communities such as the Aster Spathulifolius community and the calystegia soldanella-Artemisia princeps community. Vegetation of the Peucedanum japonicum Thunb. community with the Aster spathulifolius community was shown southward, whereas vegetation of Peucedanum japonicum Thunb. community with the calystegia soldanella-Artemisia princeps community was shown northward from the base line of Pohang at North latitude of 36" 05'. Accordingly, the Peucedanum japonicum Thunb. community was grown commonly with the Aster spathulifolius community southward of the base line of Pohang, whereas it was grown commonly with the calystegia soldanella-Artemisia princeps community northward on the east coast. All environmental conditions of habitat taken together, the optimum habitat of Peucedanum japonicum Thunb. was at Ulsan geographically and the middle region of sea cliff topography, and was suitable for alkali. sandyloam.

• Proceedings of the KSRS Conference
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• v.1
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• pp.487-490
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• 2006

Ocean Color Monitor (OCM) onboard the Indian Remote Sensing Satellite IRS-P4 has been used to retrieve chlorophyll concentration in the Bay of Bengal and the Arabian Sea using a bio-optical algorithm. Cloud masking and atmospheric corrections have been performed before applying mapping function to derive chlorophyll concentration from IRS-P4 OCM data. We have retrieved chlorophyll concentration from OCM, and MODIS during the summer and winter season along the eastern and western coast of India at every 1 degree latitude at increasing distance (25, 50, 100, 150 and 200km) away from the coast as well as near river mouths for the period 2000-2003. We have also studied spatial and temporal dynamics of monthly MODIS Aqua (for period July 2002-April 2004). The seasonal dynamics of chlorophyll concentration over the Bay of Bengal and the Arabian Sea have been discussed using OCM and MODIS for both the coastal region and the open sea.

• Journal of Applied Biological Chemistry
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• v.54 no.3
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• pp.218-224
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• 2011

This study was conducted to estimate the water quality of agricultural groundwater well located in Buan-gun, Jinan-gun, Sunchang-gun, and Jangsu-gun of Jeollabuk-do. The groundwater samples were collected at 328 sites (Buan-gun: 158, Jansu-gun: 45, Sunchang-gun: 32, Jinan-gun: 93, respectively). We measured 4 kinds of general contaminants (pH, $NO_3-N$, $Cl^-$, and COD) and 10 kinds of specific contaminants (Cd, As, $CN^-$, Hg, phenol, Pb, $Cr^{+6}$, organophosphorus, trichloroethylene, and tetrachloroethylene). Generally, the level of general contaminants and specific contaminants in the agricultural groundwater was suitable for water quality standard in all sites for agricultural irrigation water. Exceptionally, chloride concentrations were exceeded water quality standard of agricultural groundwater at some sites in western coast area of Jeollabuk-do. Although water quality standards in agricultural groundwater have been suitable, the water contaminants of agricultural groundwater in western coast area were gradually increased than eastern mountain area.

• Journal of The Korean Society of Agricultural Engineers
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• v.60 no.3
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• pp.113-121
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• 2018

The objectives of the research were 1) to develop the low-cost and high efficient desalination system to treat brackish water having high salt contents for irrigation at greenhouses near coast, and 2) to monitor and assess the effects of the brackish water desalination system on soil environment and growth in squash greenhouse cultivation area. The monitoring site was one of the squash greenhouse cultivation farm at Choengam-ri, Jinsang-myun, Gwangyang-si, Jeonnam-Do Monitoring results for groundwater irrigation water quality, and salinity showed a remarkable difference between control and treatment group. The salinity of soil at treatment group was less than at control group. While, the system made possible to increase the squash quantity from 4.7 ea to 6.3 ea at each and the average weight of the harvested squash was increased from 277.2 g to 295.1 g. The applied brackish water desalination system may be appled to reclaim sea or brackish irrigated area as alternative water resources, although long-term monitoring is needed to get more representative results at different level of salinity.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2013.06a
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• pp.270-272
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• 2013

In order to protect coastal facilities mainly from wave and current actions, the self-locking bio blocks constituting component elements of protecting structures against scouring were designed. These blocks are adapted to the sloping bottom, coastal dunes, and submerged coastal base counteracting the destructive and erosive impulse action. A series of laboratory experiments is necessary to investigate the reflection of water waves over and against a train of protruded or submerged shore structures and compare the reflecting capabilities of incident waves including wave forces. In this study the hydraulic model experiment was conducted to identify the performance of newly designed water affinity bio blocks to keep the coast slope and bottom mound from scouring by reduction of the reflection coefficient and to convince stability of the placements. Revised design of each element of blocks were also tested for field conditions. From the result of experiment, the field applicability of the developed blocks and placement is to be discussed afterward.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2018.11a
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• pp.40-42
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• 2018

지구온난화에 따른 연안의 해수면 상승은 해안에 가해지는 파랑에너지의 상승을 유발한다. 이러한 해수면의 상승은 상대적으로 수심이 깊어지는 효과를 초래하고 이는 과거 발생하지 않았던 해안지역의 침식 및 해빈에서의 모래를 유실시킨다. 특히, 국내 연안 225개소의 연안 모니터링 결과 142개소인 62%가 침식우려 이상의 등급으로 나타났다. 일반적으로 연안침식에 대응하는 방법은 호안을 쌓아 보호하게 되는 경성공법으로 외력의 변화에 따라 현장여건에 맞는 호안의 경사, 단면형상 및 재료를 선택하게 된다. 하지만 현상에 대한 불충분한 이해에 근거한 공법 적용으로 제반국가에서 다양한 피해가 발생하고 있으며, 이는 공법신뢰도 향상을 위한 기술개발 및 융합기술 도입의 필요성을 보여준다. 본 연구는 파랑저감에 효과적인 다공성 구조물Biocoast를 활용하여 해안침식피해억제를 위한 친환경 투수 바이오 콘크리트 블록을 개발하였다. 특히, 자연해변 및 호안시설에 대해 자연 및 인위적 외력에 의한 침식과 세굴로부터 연안을 보호하고, 블록의 유닛화를 통해 품질관리 및 공정관리의 효율성을 향상시킬 수 있을 것으로 사료된다.

• Korean Journal of Soil Science and Fertilizer
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• v.51 no.1
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• pp.16-27
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• 2018

To predict the influence of volcano eruption on agriculture in South Korea we evaluated the dispersal ranges of the volcanic ashes toward the South Korea based on the possibilities of volcano eruption in Mt. Baekdu. The possibilities of volcano eruption in Mt. Baekdu have been still being intensified by the signals including magmatic unrest of the volcano and the frequency of volcanic earthquakes swarm, the horizontal displacement and vertical uplift around the Mt. Baekdu, the temperature rises of hot springs, high ratios of $N_2/O_2$ and $_3He/_4He$ in volcanic gases. The dispersal direction and ranges and the predicted amount of volcanic ash can be significantly influenced by Volcanic Explosivity Index (VEI) and the trend of seasonal wind. The prediction of volcanic ash dispersion by the model showed that the ash cloud extended to Ulleung Island and Japan within 9 hours and 24 hours by the northwestern monsoon wind in winter while the ash cloud extended to northern side by the south-east monsoon wind during June and September. However, the ash cloud may extent to Seoul and southwest coast within 9 hours and 15 hours by northern wind in winter, leading to severe ash deposits over the whole area of South Korea, although the thickness of the ash deposits generally decreases exponentially with increasing distance from a volcano. In case of VEI 7, the ash deposits of Daejeon and Gangneung are $1.31{\times}10^4g\;m^{-2}$ and $1.80{\times}10^5g\;m^{-2}$, respectively. In addition, ash particles may compact close together after they fall to the ground, resulting in increase of the bulk density that can alter the soil physical and chemical properties detrimental to agricultural practices and crop growth.

• Journal of Microbiology
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• v.45 no.6
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• pp.541-546
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• 2007

Red algae are distributed globally, and the group contains several commercially important species. Griffithsia okiensis is one of the most extensively studied red algal species. In this study, we conducted expressed sequence tag (ESTs) analysis and synonymous codon usage analysis using cultured G. okiensis samples. A total of 1,104 cDNA clones were sequenced using a cDNA library made from samples collected from Dolsan Island, on the southern coast of Korea. The clustering analysis of these sequences allowed for the identification of 1,048 unigene clusters consisting of 36 consensus and 1,012 singleton sequences. BLASTX searches generated 532 significant hits (E-value <$10^{-4}$) and via further Gene Ontology analysis, we constructed a functional classification of 434 unigenes. Our codon usage analysis showed that unigene clusters with more than three ESTs had higher GC contents (76.5%) at the third position of the codons than the singletons. Also, the majority of the optimal codons of G. okiensis and Chondrus crispus belonging to Bangiophycidae were G-ending, whereas those of Porphyra yezoensis belonging to Florideophycidae were G-ending. An orthologous gene search for the P. yezoensis EST database resulted in the identification of 39 unigenes commonly expressed in two rhodophytes, which have putative functions for structural proteins, protein degradation, signal transduction, stress response, and physiological processes. Although experiments have been conducted on a limited scale, this study provides a material basis for the development of microarrays useful for gene expression studies, as well as useful information for the comparative genomic analysis of red algae.

• Korean Journal of Food Science and Technology
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• v.43 no.4
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• pp.464-468
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• 2011

Halocynthia roretzi is one of the most important cultured marine species on the southern coast of Korea. Samples were extracted using methanol (ME), ethanol (EE) and water (WE) to evaluate the antioxidant activities and antilipase activity in Halocynthia roretzi extracts. Antioxidant potentials of the samples were determined by poly-phenol content, flavonoid content, free radical scavenging activity, reducing potential, and chelating activity. The ME showed significant scavenging activity (1176 ${\mu}g/mL$ IC50 for DPPH, and 895 ${\mu}g/mL$ IC50 for ABTS assay). The IC50 for lipase inhibition activity was 12,021, 6,004, and 14,979 ${\mu}g/mL$ in the ME, EE, and WE, respectively. In conclusion, Halocynthia roretzi extracts exhibited antioxidant activities and anti-lipase activity. These results suggest that Halocynthia roretzi extracts can be potentially used as a source of antioxidant and antiobesity agents.

• Fisheries and Aquatic Sciences
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• v.15 no.2
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• pp.157-162
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• 2012

To analyze nucleotide sequence encoding internal transcribed spacer (ITS) regions specific to the Laminariaceae family, genomic DNA was isolated from six brown algae species distributed along the east coast of Korea. These included three species from the Laminariaceae family (Agarum clathratum Dumortier, Costaria costata [C. Agardh] Saunders, and Saccharina japonica Areschoug) and two species from the Alariaceae family (Undaria pinnatifida [Harvey] Suringer and Ecklonia cava Kjellman), both in the order Laminariales, and one species from the family Sargassaceae in the order Fucales (Sargassum serratifolium). Based on a sequence analysis of ITS-1 and ITS-2 for A. clathratum, C. costata, and E. cava, oligonucleotides were designed from the regions that showed sequence conservation in Laminariaceae. Following polymerase chain reaction using three sets of primers, amplification of ITS-1 and ITS-2 was detected in reactions using genomic DNA isolated from the species belonging to Laminariaceae, but not from the species belonging to the other families. The results indicate that this method can be used for the detection and identification of Laminariaceae species.