• Journal of Korean Society of Forest Science
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• v.103 no.4
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• pp.599-604
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• 2014

This study was conducted to analyze the ecological environment of the 53 uninhabitable islands of Jeju for the management formulation. The result of the Pearson correlation analysis were 0.647(p<0.01) for herbs, 0.585(p<0.01) for trees and 0.762 (p<0.01) for animals which means that there is a high correlation between the size of the forests in the uninhabitable islands and the species diversity of herbs, trees and animals. For the regression modeling to predict the forest area, the R value was 0.899 and the $R^2$ was 0.803 with 79.7% statistical significance. This study also classified the uninhabited islands based on its forest area into two classes, with a forests area of 0.5ha and with a forest of approximately 12ha. The importance value of the biodiversity in the uninhabited islands was also evaluated using DEA and the islands with higher importance, namely DMU14(0.941), DMU36(0.964), DMU44(1.000) and DMU45(0.903) were recommended to be managed. It was observed that uninhabited islands with forests had a mean importance value of 0.439 which is higher as compared to the uninhabited islands without forests with 0.096. This verified that there is close relationship between forest and biodiversity.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2009.06a
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• pp.452-455
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• 2009

The Nakdong Delta can be identified by two different geomorphic units. The first one is the upper delta. This is mostly composed of inter-distributary islands that are largely influenced by fluvial processes and attributed to the development of these islands along the river. The other one is the lower delta which is mostly composed of beach ridges. Barrier islands are largely effected by wave processes promoted by the development almost at a right angle to the river. Influenced by the longshore current which flows to the same direction, barrier islands located in the Nakdong river estuary are developing from east to west direction. As a result, the eastern end of the barrier islands are growing toward the north-west direction effected by tidal current which moves toward the same direction. Barrier islands include the Sinho Island, the Jinwoo Island, the Daema deung, the Janga Island, the Baghap deung, the Sae deung, and the Chulsae deung(Doyeo deung). They have orderly emerged from the sea since 1861. Since 2008, a new Deung, a sand dune growing under sea, has been developing rapidly from Chulsae deung to the Dadaepo beach. It made the sailing of small fisher boats impossible. Tidal currents transported a lot of sand and silt around the barrier islands. The landscape of Nakdong river estuary where many barrier islands are distributed will change rapidly affecting land environment.

• Journal of Korea Water Resources Association
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• v.36 no.3 s.134
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• pp.437-445
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• 2003

Since many islands are located in the South Sea, unexpected damage by tsunamis could be caused by mutual interferences between adjacent islands. In this study, the variation of run-up heights is investigated by using different crest lengths of incident waves and different distances between two adjacent islands. The run-up height sharply increases when the crest length of Incident waves is greater than the distance bewteen outer boundaries of two islands. The run-up height also increases as the distance between two adjacent islands decreases.

• Korean Journal of Materials Research
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• v.16 no.3
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• pp.151-156
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• 2006

A method for fabrication of nano-scale GaN structure by inductively coupled plasma etching is proposed, exploiting a thermal dewetting of Pt thin film as an etch mask. The nano-scale Pt metal islands were formed by the dewetting of 2-dimensional film on $SiO_2$ dielectric materials during rapid thermal annealing process. For the case of 30 nm thick Pt films, pattern formation and dewetting was initiated at temperatures greater $600^{\circ}C$. Controlling the annealing temperature and time as well as the thickness of the Pt metal film affected the size and density of Pt islands. The activation energy for the formation of Pt metal island was calculated to be 23.2 KJ/mole. The islands show good resistance to dry etching by a $CF_4$ based plasma for dielectric etching indicating that the metal islands produced by dewetting are suitable for use as an etch mask in the fabrication of nano-scale structures.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.42 no.6
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• pp.650-656
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• 2009

Recently, bottlenose dolphins have frequently appeared in coastal waters of the Jeju Islands. To determine whether these individuals belong to one or more pods, the Cetacean Research Institute (CRI) established visual and photo-identification surveys in the Jeju Islands from November 2007 to July 2009. During visual surveys, pods composed of 10 to 80 individuals were sighted mainly in the northeastern and northwestern of Jeju Islands. Eighty-nine individuals were identified and cataloged by photo-identification using natural nicks and notches on their dorsal fins. Thirty-six individuals were identified three times or more, and nine individuals were identified five times during seven surveys. One individual appeared in November 2007, August 2008, October 2008, April 2009, and July 2009. The results of our study confirm that these dolphins represent a coastal resident stock. Futhermore, we will establish dolphin abundance, management, and usage studies using continuous visual and photo-identification surveys.

• Microbiology and Biotechnology Letters
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• v.37 no.3
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• pp.189-196
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• 2009

Bacteria were isolated from roots of plants belonging to family Solanaceae and Gramineae, inhabited in Dokdo island. Fifty six endospore-forming bacteria grown on tryptic soy broth (TSB) agar medium and 23 nitrogen-fixing bacteria (NFB) grown on nitrogen free agar medium were isolated, respectively. The isolates were partially identified by analyzing the 16S rDNA and categorized into phylogenetic groups. The 16S rDNA sequences of each identified isolates were compared with sequences of each type strains to analyze phylogenetic relationship by phylogenetic tree. As a result, endospore-forming bacteria and nitrogen-fixing bacteria were classified into 4 and 6 lineage groups, respectively. Among these isolated, 18 were presumed to be novel species candidates based on the similarity (lower than 98%) analysis of the l6S rDNA sequences.

• Transactions of the Korean hydrogen and new energy society
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• v.14 no.4
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• pp.348-358
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• 2003

According to Electricity Acceleration Law of Rural Area recently, the needs for replacement of a small scale diesel power generation facility which supplied electricity to 10-50 households Remote Islands has been revealed due to high operating and maintenance cost of Diesel Power Generation. Optimization of electric power system for Small Remote Islands must be made considering the economics, reliability and stability as power sources and estimation of total construction cost of those power stations. For its purpose, an assessment of power generation options such as Photovoltaic, Fuel cell, Wind-hybrid was implemented, economic evaluation of power supply shows the Photovoltaic, Fuel Cell for few household's islands and Diesel, Wind-hybrid for more inhabited islands. Power supplied by Diesel shows the best response to increasing electric demand and system reliability even with its lower economic value. Those who are in charge of power planning have to pay attention to system reliability, stability and operating characteristics of candidate's power supply besides its economics.

• Journal of Ecology and Environment
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• v.33 no.2
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• pp.105-114
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• 2010

The principal objective of this study was to characterize the relationships between geographical conditions (e.g., island area, distance to mainland) and landscape structures of uninhabited islands, and to evaluate the effects of islands and their landscape structures on species richness. One hundred randomly selected islands and 5,000 m buffered areas derived from the boundaries of each island were used to summarize the number of observed bird species, and landscape pattern indices, particularly patch density, edge density, shape index, and mean nearest neighboring distance. Spatial arrangements of individual patch type at the class level, which are markedly affected by the distance from an island to the mainland, have a superior ability to explain the variances in species richness, as compared to the geographical conditions and landscape pattern indices at the landscape level. The results demonstrate that the patch type landscape structure is the primary factor affecting species richness, as well as the distance to the mainland. In particular, landscape pattern indices of cropland/pasture and woody cover are statistically significant in terms of explaining species richness, which suggests that food resources and appropriate conditions in landscape structures of habitat types are assumed as important elements in attracting bird species. This study also proposes the importance of evaluation on the landscape structure of each island, in order to designate protected areas and to establish a management plan for species conservation in uninhabited islands.

• Mycobiology
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• v.28 no.3
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• pp.133-141
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• 2000

Twenty species representing five genera of arbuscular mycorrhizal fungi were isolated from twenty-four soil samples of the rhizosphere of the family Gramineae in Paekryung and Daecheong islands. A few species such as Glomus invermaius, G. marcrocapus var. marcrocarpus and Scutellospora coralloidea were recorded for the first time in Korea. The number of spores per 10g of soil was in the range of $8{\sim}337$ in Paekryung and $16{\sim}349$ in Daecheong island, respectively. The number of species per 10g of soil was $2{\sim}8$ species in Paekryung and $2{\sim}7$ species in Daecheong, respectively. Among them, G. macrocarpus var. macrocarpus was the most abundant species in both islands. The species diversity and evenness were almost similar in Paekryung and Daecheong Islands. Based on the host plants in two islands, the species diversity showed the highest value of 1.63 in Ischaemum crassipes, whereas the eveuness of species showed the lowest value of 0.35 in Eragrostis ferraginea.

• 한국균학회소식:학술대회논문집
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• 2014.10a
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• pp.44-44
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• 2014

Yeasts were isolated from wild flowers of some islands and mountains such as Jeju-do, Ulleungdo, Yokjido, Seonyudo and Gyejoksan, Oseosan, Beakamsan and Deogyusan in Korea and were identified by comparison of nucleotide sequences for PCR-amplified D1/D2 region of 26S rDNA or internal transcribed pacer(ITS) 1 and 2 including 5.8S rDNA using BLAST. Seventy two yeast strains of two hundred eighty nine species were isolated from wild flowers in islands and mountains, Korea. Among them, Cryptococcus species were isolated the most dominantly, and Metschnikowia reukaufii were also isolated thirty species, 10.3% of total strains. Twenty-three species including Cryptococcus aureus were overlapped between yeast strains of the islands and mountains. Some physiological functionality of the culture broth and cell-free extracts from two hundred eighty nine yeast strains were determined. The supernatant of Candida sp. 78-J-2 showed antioxidant activity of 22.5%, and supernatant of Metschnilowia reukaufii SY44-6 showed anti-gout xanthine oxidase inhibitory activity of 49.6% and whitening tyrosinase inhibitory activity of 38.4%, respectively.