• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.57 no.3
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• pp.205-213
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• 2021

Two specimens of Hemitrygon izuensis (395.8-471.5 mm in disc width), belonging to the family Dasyatidae (Myliobatiformes), were collected from the waters off north-eastern Jeju-do Island in June 2016 and Pohang in August 2019. This species was characterized by having no spots on dorsal side of disc, white ventral tail fold and short preorbital snout length (15.6-18.3% of disc width). This species is similar to H. akajei and H. sinensis reported in Korea, but differs in small denticles on mid-line of dorsal surface of disc (absent in H. izuensis vs. present in H. akajei and H. sinensis), the length of ventral tail fold (28.1-31.0% in H. izuensis vs. 48.0-48.6% in H. akajei vs. 45.0% in H. sinensis), color of ventral tail fold (white in H. izuensis vs. black in H. akajei and H. sinensis) and small tubercles on the posterior part of tail (absent in H. izuensis vs. present in H. akajei and H. sinensis). We suggest a Korean name for H. izuensis as "I-ju-gal-saeg-ga-o-li" following Kim et al. (2019).

• The Korean Journal of Mycology
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• v.51 no.1
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• pp.25-38
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• 2023

Three fungal strains belonging to the class Sordariomycetes were isolated from soil collected on Jeju Island and Gyeongsangbuk-do, Korea. They were identified as Diaporthe endophytica (KNU-JJ-1809), Faurelina indica (KNU-JJ-1830), and Trichoderma ivoriense (KNU-4-KH1). KNU-JJ-1809 produced beta conidia that were straight, curved, hyaline, smooth-walled, with a diameter of 16.5-25.0×0.6-1.7 ㎛. The conidia of strain KNU-JJ-1830 were hyaline to light green, thin, clavate, round, truncate base, had guttules at both ends, with a diameter of 2.5-5.2×1.7-3.8 ㎛. The conidia of strain KNU-4-KH1 were oblong or ellipsoidal, smooth-walled, greenish, with a diameter of 2.2-4.4×2.2-3.6 ㎛. Internal transcribed spacer regions, partial large subunit, translation elongation factor 1-alpha, β-tubulin, and calmodulin genes were used to confirm the strains, and their cultural and morphological characteristics. To our knowledge, this is the first report on D. endophytica, F. indica, and T. ivoriense in Korea.

• The Korean Journal of Malacology
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• v.31 no.4
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• pp.267-272
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• 2015

This study was conducted in order to elucidate the dissemination mechanism of P. olseni using field and laboratory experiments. For this purpose, we quantified the level of P. olseni infection in buried (healthy) and surfaced (gapped) R. philippinarum from a clam bed on Wi-do Island on the west coast of Korea. In addition, the levels of internal and released P. olseni cells from artificially infected (and later dead) R. philippinarum were monitored for 8 days using the RFTM-2 M NaOH lysis method. Our results indicate that P. olseni cells in buried R. philippinarum was $2,655,625{\pm}1,536,936cells/clam$; the level in gapped R. philippinarum was considerably lower, $28,203{\pm}24,889cells/clam$ (p < 0.05). In the laboratory experiment, the P. olseni cells remained in the host tissue 2 days after death was approximately 50% lower than the level of infection measured in living clams. The level dropped to 20% 4 days after death and to 1.5% 6 days after death; eight days after death, P. olseni cells were undetectable since the R. philippinarum flesh had completely decomposed. The level of released cells on the day of death was only 0.05% of the internal level in live R. philippinarum; however, the level increased to 2.3% 5 days after death then gradually decreased and no released cells were detected 8 days after death. Therefore, our laboratory experiment suggest that the low level of P. olseni infection observed in gapped R. philippinarum at Wi-do Island could be caused by lysis of the most of P. olseni cells during the decomposition of dead R. philippinarum tissues. Until the end of decomposition of R. philippinarum, 6.68% of the total amount of P. olseni was released within 8 days. Our study showed that the amount of P. olseni cells from dead host is a considerably higher level than naturally released from healthy R. philippinarum, suggesting that death of the host plays an important role in the dissemination of P. olseni.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.39 no.9
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• pp.735-742
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• 2015

In this paper, we compare and verify the prediction accuracy and feasibility for wind resources on a wind farm using the Weather Research and Forecasting (WRF) model, which is a numerical weather-prediction model. This model is not only able to simulate local weather phenomena, but also does not require automatic weather station (AWS), satellite, or meteorological mast data. To verify the feasibility of WRF to predict the wind resources required from a wind farm pre-feasibility study, we compare and verify measured wind data and the results predicted by WAsP. To do this, we use the Pyeongdae and Udo sites, which are located on the northeastern part of Jeju island. Together with the measured data, we use the results of annual and monthly mean wind speed, the Weibull distribution, the annual energy production (AEP), and a wind rose. The WRF results are shown to have a higher accuracy than the WAsP results. We therefore confirmed that WRF wind resources can be used in wind farm pre-feasibility studies.

• Journal of the Mineralogical Society of Korea
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• v.22 no.1
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• pp.49-61
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• 2009

We studied the mineral composition and mineral distribution pattern of 131 surface sediments collected at the cruise in 2000 and 2007 from Southeastern Yellow Sea, South Sea of Korea and Southern part of Jeju Island. Mineral compositions of surface sediments were determined using the quantitative X-ray diffraction analysis. Surface sediments were composed of rock forming minerals (quartz 37.4%, plagioclase 11.7%, alkali feldspar 5.5%, hornblende 3.1%), clay minerals (illite 19.2%, chlorite 4.7%, kaolinite 1.8%) and carbonate minerals (calcite 10.7%, aragonite 3.4%). Distribution of clay minerals is very similar with fine-grained sediments, and especially same as the distribution of HSMD (Hucksan Mudbelt Deposit), SSKMD (South Sea of Korea Mudbelt Deposit) and JJMD (Jeju Mudbelt Deposit). The coarse sediment seemed to be relic sediment during the last glacial maximum and mainly consisted of rock forming minerals. Whereas the fine sediments mainly composed of clay minerals. Based on the clay mineral composition, main ocean current and geographical factor, HSMD and SSKMD might have derived from the rivers around the Korean Peninsula. However, JJMD is complex mudbelt deposit, which formed by Korean rivers and oceanic sediments.

• Korean Journal of Plant Resources
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• v.24 no.5
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• pp.650-658
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• 2011

The 460 collections of 60 crops were collected during 34 days from 28 November to 31 December 2008. The 295 accessions of 43 crops, 49 accessions of 24 crops and 116 accessions of 42 crops were collected in Kangwha, Ulreung and Jeju island in this exploration. Among the total collections, the portion of the food crops, vegetable or ornamental crops and industrial crops were 54.8%, 25.4% and 19.8%, respectively. The farmers conserved 48.4% to 53.6% of the landrace crops for 31 to 50 years. Furthermore, 13.1% to 18.7 % of the collections were cultivated over generation to generation. Most of the crop seeds were conserved by woman farmers aged from 61 to 80 years old. The 82.9% of the seed distributors were also woman farmers, whereas 17.1% was distributed by man farmers.

• Archives of design research
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• v.17 no.4
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• pp.15-26
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• 2004

After 19th century of Chosun Dynasty Gilsnagmunja-do such as longevity, good fortune, health, well-being which was explosively prevalent and Hyojemunja-do which was panoramically decorated with eight characters of filial piety, fraternal devotion, loyalty, trust, courtesy, commitment, integrity and humility for enlightment of the public under the name of political ideology are consistency or same origin in traditional concept of Orient. Therefore, in view of Western standard, they are showing an illustration and a photograph of characters in design. There are some differences in way of expressions. They were considerably popular not only in Chosun Dynasty but in China, Japan and Vietnam where belong to the cultural territory of chinese characters. Though, Hyojemunja-do which was built-up in the late period of Chosun Dynasty and developed fro chinese mode is a very peculiar iconography and mode of Chosun Dynasty. Hyojemunja-do is also classified from Chinese Nianhua designed for supply of Conficianism ethics or Folk Painting designed for practical use in chinese cultural territory. In the late period of 19th century, Hyojemunja-do which was re-built with creative modeling has been developed in peculiar mode in the province of Kyunggi, Kangwon(Kwan dong region), Kwanseo region, Jeju island and Namdo region by the diversified level of painters.

• Korean Journal of Plant Resources
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• v.26 no.5
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• pp.589-596
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• 2013

Vaccinium bracteatum Thunb. is an evergreen plant that belongs to the Genus Vaccinium distributed in Korea, and its fruit has been used for food by the common people and thus has a high possibility of commercialization. Therefore, the habitat environment and individual characteristics of V. bracteatum in Jeju Island were investigated to obtain the basic data for commercialization and preservation. The results showed that V. bracteatum is mostly distributed on the southern slope of Mt. Halla at an altitude of 100 to 500 m. V. bracteatum that occurred in the quadrat were total 30 individuals, which had an average height of 6.0 m, an average DBH of 7.8 cm, and an average number of trunk of 4.3. As for the community structure of the habitat, the average percentage of vegetation cover for the tree layer was 36%, while that for the subtree layer was 78%, which emphasized the importance of the subtree layer. The total number of species that occurred in the quadrat was 76. For the tree layer, total 10 species occurred, which include 2 species of evergreen coniferous trees, 3 species of evergreen broad-leaved trees, and 5 species of deciduous broad-leaved trees. For the subtree layer, total 24 species occurred, which include 1 species of evergreen coniferous tree, 11 species of evergreen broad-leaved trees, and 10 species of deciduous broad-leaved trees. Among these, Eurya japonica Thunb. was the species with a high relative contribution, which threatened V. bracteatum For the shrub layer, 27 species occurred including Cinnamomum japonicum Siebold, and for the herbaceous layer, 64 species occurred including Ardisia crenata Sims. The similarity between the habitats of V. bracteatum was very low, and it did not prefer a characteristic community. The V. bracteatum community around Shinrei stream was distributed on the surrounding area adjacent to the slope of the stream rather than the slope. There were a lot of basins, but the branches, which did not receive sunlight, had withered. It is thought that V. bracteatum would decline if the forest formation continues.

• Journal of Korean Society for Geospatial Information Science
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• v.19 no.2
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• pp.29-37
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• 2011

Forest fire in Korea has been controlled by local government, so that it is required to understand the characteristics of regional forest fire occurrences for the effective management. In this study, to analyze the patterns of regional forest fire occurrences, we divided South Korea into nine zones based on administrative boundaries and performed spatial statistical analysis using the location data of forest fire occurrences for 1991-2008. The spatial distributions of forest fire were analyzed by the variogram, and the risk of forest fire was predicted by kriging analysis. As a result, forest fires in metropolitan areas showed strong spatial correlations, while it was hard to find spatial correlations of forest fires in local areas without big city as Gangwon-do, Chungcheongbuk-do and Jeju island.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.8 no.4
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• pp.401-410
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• 2003

Three beaches of the Seogwang-ri coast in the western part of Wu Island, Jeju-do, are solely composed of rhodoliths (red algal nodules). The beach sediments are coarse sand to granule in size and they show the banded distribution according to size. Commonly the larger pebble-sized rhodoliths are concentrated near the rocky coast, resulting from the transportation of the nodules from shallow marine environments by intermittent typhoons. Based on the internal texture of the rhodoliths, it appears that crustose red algae, Lithophyllum sp., is the main contributor for the formation of the rhodolith. The coarse sand to granule-sized grains show that they started to grow from the nucleus as rhodoliths, but the surface was severely eroded by waves. However, the pebble to cobble-sized grains exhibit the complete growth pattern of rhodoliths and sometimes contain other calcareous skeletons. It is common that encrusting red algae are intergrown with encrusting bryozoan. The surface morphology of rhodolith tends to change from the concentric to domal shape towards the outer part. This suggests that the rhodolith grew to a certain stage by rolling, but it grew in more quiet condition without rolling as it became larger. Aragonite and calcite cements can be found in the pores within rhodoliths (conceptacle, intraskeletal pore in bryozoan, and boring), and this means that shallow marine cementation has occurred during their growth. Growth of numerous rhodoliths in shallow marine environment near the Seogwang-ri coast indicates that this area has suitable oceanographic conditions for their growth such as warm water temperature (about 19$^{\circ}C$ in average) and clear water condition due to the lack of terrestrial input of volcanoclastic sediments. Fast tidal current and high wave energy in the shallow water setting can provide suitable conditions enough for their rolling and growth. Typhoons passing this area every summer also influence on the growth of rhodoliths.