• Korean Journal of Materials Research
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• v.21 no.10
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• pp.525-531
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• 2011

Two dimensional (2D) arrays of noble metal nanoparticles are widely used in the sensing of nanoscale biological and chemical events. Research in this area has sparked considerable interest in many fields owing to the novel optical properties, e.g., the localized surface plasmon resonance, of these metallic nanoarrays. In this paper, we report successes in fabricating 2D arrays of gold nano-islands using nanosphere lithography. The reproducibility and the effectiveness of the nano-patterning method are tested by means of spin coating and capillary force deposition. We found that the capillary force deposition method was more effective for nanospheres with diameters greater than 600 nm, whereas the spin coating method works better for nanospheres with diameters less than 600 nm. The optimal deposition parameters for both methods were reported, showing about 80% reproducibility. In addition, we characterize gold nano-island arrays both geometrically with AFM as well as optically with UV-VIS spectrometry. The AFM images revealed that the obtained nano-arrays formed a hexagonal pattern of truncated tetrahedron nano-islands. The experimental and theoretical values of the geometric parameters were compared. The 2D gold nano-arrays showed strong LSPR in the absorption spectra. As the nano-islands increased in size, the LSPR absorption bands became red-shifted. Linear dependence of the plasmon absorption maximum on the size of the gold nano-islands was identified through the increment in the plasmon absorption maximum rate for a one nanometer increase in the characteristic length of the nano-islands. We found that the 2D gold nano-arrays showed nearly seven-fold higher sensitivity of the absorption spectrum to the size of the nano-islands as compared to colloidal gold nano-particles.

• Korean Journal of Plant Taxonomy
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• v.38 no.3
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• pp.315-332
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• 2008

To elucidate the distribution of broad-leaved evergreen plants of the central part of the Yellow Sea, we surveyed 136 islands of Incheon from May 2006 to March 2008. In the present survey, twelve broad-leaved evergreen species were found on 77 islands, which included 28 inhabited and 49 uninhabited islands. Among them, the most popular plants were the following: Euonymus japonicus Thunb., Elaeagnus macrophylla Thunb., Camellia japonica L., and Cyrtomium falcatum (L.f.) C. Presl. These plants were found growing on Baengnyeong Island, the northmost island among those surveyed, near $N 37^{\circ}60^{\prime}$. On the other hand the following four species are found up to Deokjeok-myeon only, near N $N 37^{\circ}10^{\prime}$: Hedera rhombea (Miq.) Bean,, Quercus acuta Thunb. ex Murray for. acuta, Neolitsea sericea (Blume) Koidz., and Trachelospermum asiaticum (Siebold & Zucc.) Nakai. However, these plants are usually found growing in the southern or southwestern coastal region of the Korean Peninsula. Thus the distribution of the broad-leaved evergreen plants growing on these high latitude islands might be influenced by a warm current of the Yellow Sea. The distribution of broad-leaved evergreen plants on each island is described.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.22 no.5
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• pp.57-67
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• 2019

Water-Birds are the birds that occupy the highest proportion in Korea, inland wetlands and reservoirs provide them with a good environment as habitat, but their habitats have been losing because of thoughtless development. Therefore, artificial plant islands in reservoirs are important for improving habitat environment and providing food resources. However, there are no research and standards on the built and management of artificial plant islands. So this study is to find out the density of bird using artificial plant island as habitat through monitoring using UAV focus on the Cheonho-reservoirs located in Seobuk-gu, Cheonan-si(Middle Chungcheong Province). Further, the correlation analysis with environmental factors was conducted to determine the effect of artificial plant islands as habitats for water-birds. The supervised classification of the three-time images taken by the drone identified 244 white-billed ducks and 46 mandarin ducks. The utilization rate was different for each photographed date, and more individuals were identified in wet artificial plant islands than dry ones. As a result of analyzing the utilization follow environmental factors, the distance from the trail showed a significant correlation, and the other factors did not have a statistically significant effect. This study is the first case of the UAV monitoring method of the water-birds using artificial plant islands in the reservoir, and can be used as the basic data for the built and management.

• Journal of the Korean Society of Marine Environment & Safety
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• v.28 no.6
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• pp.853-865
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• 2022

In this study, from August to October 2019, we conducted a survey of the spatial distribution and dominant species of macrobenthos on the rocky intertidal zones of 38 specified islands distributed along the southern coast of Korea. On the basis of observation made using 50 × 50 cm quadrats, we identified a total of 80 species, among which, Mollusca were the most abundant fauna, with 54 species that accounted for 67.4% of the total, followed by Crustacea with 15 species (18.7%). The recorded numbers of Cnidaria, Porifera, and Echinodermata species ranged from 1 to 6. In terms of the regional patterns of species richness, specified islands in Yeosu were found to be the most species rich, supporting 61 species, whereas islands in Hadong, Namhae, and Chujado were found to have a similar level of species richness, ranging from 42 to 46 species. Islands in Boseong and Goheung were home to the fewest species, with only 29 species being recorded. At the sampling station scale, we noted a considerable difference in faunal richness, ranging from 6 (St. 6) to 33 (St. 20) species. Among the recorded species, Echinolittorina radiata was identified as the dominant species on 15 specified islands, with the next most abundant species being Tetraclita japonica, considered an indicator species of climate change, which was recorded on 11 islands. In terms of frequency, E. radiata, found on 36 islands, was identified as the most frequently occurring species, followed by Reishia clavigera (30 islands), Mytilisepta virgata (29), Nerita japonica (28), Ligia. exotica (27), and Littorina brevicula (26). Of the 80 species identified, 9, 4, and 2 species of Mollusca, Crustacea, and Cnidaria, respectively, are classified as Marine fauna of accepted foreign export, whereas 50 are Red List species, 44 are species of Least Concern, 3 are Data Deficient species, and 1 species was not evaluated. However, during the survey, we found no Near Threatened or Not Applicable species. On the basis of the findings of this survey, it would appear that the abundance and richness of macrobenthic fauna inhabiting the rocky intertidal zones of specified islands along the southern coast of Korea differ according to different habitat conditions, particularly with respect to the duration of exposure and the extent and properties of the substrata. The findings of this study will provide baseline data for future monitoring and management of specified islands in Korea.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.2
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• pp.28-36
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• 2018

Islands are supplied with power from diesel generation or from photovoltaic power generation, and problems with offshore environmental impacts (age deterioration, salt pollution), environmental pollution (exhaust gas, noise, dust) and power generation costs (installation, maintenance) have increasingly emerged. In 2016, the cost recovery rate was only 27%, and deficits reached 73% on 65 islands managed by KEPCO. In terms of deficits, the costs incurred in the power generation sector accounted for 91%, with the ratio of fixed costs at about 60%. Analysis suggests that operating costs can be reduced with an optimal power supply system that improves power generation efficiency and makes operating systems more efficient. Therefore, it is possible to simplify fuel transportation and facility maintenance, because one island integrates the power plants of remote islands, and offshore cable is used to supply power to the other islands. From the economic evaluations in this paper, an algorithm deciding offshore cable layout validity for an integrated power supply between adjacent islands is presented. Simulation results based on the proposed algorithm confirmed that an integrated power supply is economical for existing stand-alone operations on islands having diesel generation, low peak power, and near distances.

• Proceedings of the Korean Society of Crop Science Conference
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• 2017.06a
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• pp.360-360
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• 2017

Morphological characteristics indicating agronomic features and yield components (trunk length, trunk diameter, thickness of bark, pith density, dry-matter percentage of pith and starch concentration in pith) of sago palms (Metroxylon sagu Rottbøll) were compared between the 27 populations grown in the islands in Southeast Asia (West Sumatra, South Sumatra, West Java, Southeast Sulawesi, Ternate, Halmahera and Seram in Indonesia) and the 20 populations grown in Melanesia (West Papua in Indonesia, East Sepik and New Ireland island in Papua New Guinea). The average starch yield calculated based on the yield components was $310kg\;plant^{-1}$ and $244kg\;plant^{-1}$ in the islands in Southeast and Melanesia, respectively. The variation of starch yield in Melanesia (CV: about 80%) was larger than that in the islands in Southeast Asia (CV: about 60%). The difference in starch yield in the islands in Southeast Asia was mainly attributed to the trunk diameter breast height and the dry-matter percentage of pith. In contrast, the differences in trunk length and dry-matter percentage of pith mainly accounted for the difference in starch yield in Melanesia. The sago palms in the islands in Southeast Asia had a comparatively thick and short trunk and those in Melanesia had a comparatively thinner and longer trunk. However, the average pith dry-matter yield was almost same level as $400kg\;plant^{-1}$ in both the islands in Southeast Asia and Melanesia. The difference in starch yield between the two areas was attributed to the difference in starch concentration in pith, 77% and 58% in the islands in Southeast Asia and Melanesia, respectively.

• Proceedings of KOSOMES biannual meeting
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• 2018.06a
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• pp.151-151
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• 2018

• 한국신재생에너지학회:학술대회논문집
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• 2007.11a
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• pp.244-244
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• 2007

• Proceedings of the Korean Geotechical Society Conference
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• 1992.10a
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• pp.95-106
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• 1992

The paper presents general engineering properties of soft marine sediments and related geotechnical problems associated with construction of artificial islands. Both of the data from foreing and domestic sources are utilized. The selection of soil improvement methods are also discussed.

• Journal of the Korean Chemical Society
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• v.47 no.6
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• pp.659-662
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• 2003