• Journal of Species Research
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• v.11 no.2
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• pp.89-93
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• 2022

Three heterotrophic euglenids from marine water column (Seodo port, Yeosu) and freshwater sediment (Seodong-chun, Incheon), Korea were identified as Entosiphon oblongum Cavalier-Smith and Vickerman, 2016; Euglena longa (Pringsheim, 1936) Marin and Melkonian, 2003; and Keelungia pulex Chan and Moestrup, 2013 based on morphological characters and 18S rDNA sequence analysis. These species are reported taxonomically for the first time from Korea and are described with micrographs. Diagnoses of these species are as follows. Entosiphon oblongum: phagotrophic, gliding, size in vivo, 23.1-29.3 ㎛ (Avg. 26.5 ㎛, n=30) long, ovate with a protrusive feeding siphon (apparatus), several deep grooves and two heterodynamic flagella. Euglena longa: osmotrophic, swimming, size in vivo, 32.3-52.2 ㎛ (Avg. 42.2 ㎛, n=26) long, elongated with many paramylum granules and two flagellar. Keelungia pulex: phagotrophic, gliding, size in vivo, 13.5-19.7 ㎛(Avg. 16.4 ㎛, n=97) long, oblong to ovoid with a hook-shaped ingestion apparatus, several dorsal ridges and two flagella.

• Ocean and Polar Research
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• v.24 no.4
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• pp.457-464
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• 2002

Distribution and stock assessment of mega-benthos living in the shallow hard bottom around Dokdo were studied in July,2000. Depth and topographical conditions have affected to the densities and biomass of benthic animals. In shallow area, less than 10 m depth, turbo shell Batillus cornutus, mussel, Mytilus corusucs were dominated and showed distinct patterns in vertical distribution. On the other hand, the area over 10m depth, it showed diverse pattern depending on topography. Turbo shell, mussel and sea cucumber Stichopus japonicus were dominated in terms of fishery resources, but abalones were rarely sampled. Stock assessment were estimated to be 6.54 M/T, 3.89 M/T and 8.92 M/T, respectively. Some parts of coastal hard bottom around Dokdo, such as the area between Dongdo and Seodo, seemed to play an Important role as nursery ground. Therefore, it is necessary to the environmental monitoring for coastal fishery managements aspects.

• Lingua Humanitatis
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• v.8
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• pp.199-221
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• 2006

The writing systems of the Silla dynasty, the Kugyol(口訣), had influenced the earlier states of Japanes Kunten(假片) during the 8th century. Japanese developed their own writing system, Kunten(訓点) after the 9th century. The Silla Kugyol was inscribed by Gagpil(角筆), a kind of ancient stylus, which seems to be originated in China and India. There are two main streams of Asian script culture. One is from China: a brush-pen culture for East asian calligraphy, named Seoye(書藝) or Seodo(書道). The other is from India: a tusk-pen culture for inscribing Buddha's words. In Korean peninsular, we can find the traces from Buddist texts inscribed by the Gagpil, a tusk-pen. We can find new writing system in the books of the Silla, penod, Panbilyanglon(判比量論), Hwaeommuneuiyogyol(華嚴文義要訣) etc. The scripts inscribed by gagpil was a totally phonetic system with dots and lines etc., like Hangul strokes was invented by I king Sejong 800 years later. The old system was used until 15th century before the invention of Hangul scripts.

• Journal of Korean Society of Water and Wastewater
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• v.33 no.5
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• pp.341-351
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• 2019

The purpose of this study was to evaluate vulnerability of drought in small island areas. Vulnerability assessment factors of drought were selected by applying the factor analysis. Ninety Eup/Myon areas in small island were evaluated to vulnerability of drought by entropy method adapting objective weights. Vulnerability consisted of climate exposure, sensitivity, and adaptive capacity. A total of 22 indicators were used to evaluate and analyze vulnerability of drought in small island areas. The results of entropy method showed that winter rainfall, no rainfall days, agricultural population rate, cultivation area rate, water supply rate and groundwater capacity have a significant impact on drought assessment. The overall assessment of vulnerability indicated that Seodo-myeon Ganghwa-gun, Seolcheon-myeon Namhae-gun and Samsan-myeon Ganghwa-gun were the most vulnerable to drought. Especially Ganghwa-gun should be considered policy priority to establish drought measures in the future, because it has a high vulnerability of drought.

• Tunnel and Underground Space
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• v.18 no.1
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• pp.69-79
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• 2008

Dokdo is a volcano edifice originating from an oceanic island that was formed around 3 million to 2.2 million years ago, and it consists of Dongdo(eastern island) and Seodo(western island). Even though Dokdo is a small volcanic island, Dokdo has infinite potential value and significant economic, social, scientific, and technical aspects due to its resources, ecological and territorial value. In addition, it is of national interest with regards to the dispute with Japan over the dominium of Dokdo. A need to evaluate the ground stability of Dokdo, especially in Dongdo, has been seriously raised recently due to the various cracks caused by the progressive weathering and corrosion. This study dealt with the geology and geological layers of Dokdo and identified the status of ground cracks as the previous research to evaluate the ground stability of zones of concern in Dongdo. Also, this study analyzed the relationships between physical and mechanical properties with rock types. The results showed that the values of rock properties in Dokdo are lower contrary to the general rocks in Korea, and tuff was especially affected by the weathering and corrosion.

• The Korean Journal of Mycology
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• v.45 no.4
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• pp.284-291
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• 2017

In this study, arbuscular mycorrhizal fungi (AMF) were isolated from rhizosphere soils of Dokdo Island. Based on their morphological characteristics and 18S rDNA sequence analysis, eight species belonging to seven genera were identified: Acaulospora longula, A. mellea, Claroideoglomus claroideum, Diversispora aurantia, Funneliformis mosseae, Gigaspora margarita, Paraglomus occultum, and Septoglomus constrictum. No differences were noted between the AMF isolated from Dongdo and Seodo in Dokdo Island, and all of these AMF have been reported previously in Korea. These results could be useful for diversity and functional analyses of AMF in Korea.

• Journal of Ecology and Environment
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• v.32 no.4
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• pp.295-304
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• 2009

To understand the properties of soil in Dokdo, we collected soil samples from 12 locations on Seodo and 23 locations on Dongdo, in Dokdo of Gyeongsangbuk-do Province in 2007-2008 and analyzed the soil's physical and chemical characteristics. Sand comprises the largest component (49.37%) of Dokdo soil, followed by silt (40.70%) and clay (9.93%). The soil structure consists mostly of sand loam, followed by loam and silt loam. The pH level of soils from Dokdo varied dramatically among sampling sites and seasons, ranging from 3.36 to 8.02. The total ion content of Dokdo soil also varies greatly among survey places and periods, but in general the total ion content was high in summer when vegetation develops, and low in spring. The exchangeable cation contents of the soil showed low levels in samples where the soil pH was low, including habitats dominated by Agropyron tsukushiense var. transiens and Echinochloa crus-galli, whereas the exchangeable cation contents were high where the organic contents were high, as in habitats dominated by Liriope platyphylla and Artemisia japonica subsp. littoricola. Soil N contents varied greatly among survey sites and higher N contents were found in soil inhabited by Chenopodiaceous plants than in habitats inhabited by other plants. The substantial differences in phosphorus contents among sites were related to excrement of black-tailed gulls. To understand the basic physical and chemical features of the soil on Dokdo, it will be necessary to conduct seasonal and long-term research on soil pH, ion contents, organic contents, N and P, as well as obtaining precise data from samples collected at different depths.

• Korean Journal of Food Science and Technology
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• v.30 no.5
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• pp.1040-1044
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• 1998

Tetrasodium pyrophosphate peroxidate can be crystallized as a hydrogen-peroxide-bound salt from the solution of tetrasodium pyrophosphate and hydrogen peroxide. The antimicrobial activity and stability of the compound were tested for the use as a food preservative. It showed antimicrobial activities against several food spoilage microorganisms at the concentration of 0.1% (w/v), and was stable for 80 days in room temperature as a form of 70% hydrogen-peroxide-bound tetrasodium pyrophosphate peroxidate. It was also stable at the boiling temperature but decomposed significantly in the presence of metal ions. The compound can be an effective food preservative at the 0.2% (w/v) concentration, which contains 0.03% (v/v) hydrogen peroxide. The compound could be commercialized if the application area and usage direction as well as the removal method of hydrogen peroxide were developed.

• Journal of The Geomorphological Association of Korea
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• v.28 no.2
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• pp.45-57
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• 2021

In this study, the changes in morphology of Dokdo's gravel beach and its responses due to a storm event were analyzed using the aerial photos and 3D LiDAR data obtained during an ecosystem survey of the Dokdo in 2020. Dongdo Island's gravel beach, shown by aerial photo analysis, increased in area due to sedimentation after the construction of a dock, but there was no more significant changes in area after having grown to Sutdolbawi inside the dock. The changes in volume of the gravel beach were indicated based on 3D data acquired in May and November 2020. A strong typhoon that passed in September, 2002, caused erosion on the backshore and sedimentation on the foreshore and formed the berm by about 1.5 to 2 m high. The analysis showed that the sedimentation was 94.76 m³ in volume and 329 m² in area and the erosion was 250.75 m³ in volume and 603m² in area, which suggested that the overall change of the gravel beach was erosion. The changes in the morphology of the gravel beach on Seodo Island occurred with the seasons along with the changes in area. In addition, berms of different altitudes appeared on the southern and northern sides of the spit, which was also estimated to have formed by the seasonal current direction and wave energy.

• Journal of The Geomorphological Association of Korea
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• v.26 no.4
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• pp.33-45
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• 2019

The shore platforms at Dok-do could be an important and clear indicator showing dimensional reduction of Dok-do. Especially flat type shore platforms are distributed in the southern coast of Dok-do island, composed of weak rocks against erosional resistance like interbedded lapilli tuff and massive tuff breccia. The distribution of shore platform is partially related to the wind direction at Dok-do island. The primary SW- and secondary SE winds are representative among wind directions at Dok-do, maintaining from spring to the autumn. Therefore, wide shore platforms could be developed by waves approaching from SW and SE directions in the southern coast of Dok-do. The sea stacks like Gunham-rock, Neopdeok-rock, Keungaje-rock and Jakeungaje-rock on the western coast are also considered to be formed by wave erosion from the SE direction. The shore platforms in the southern coast of Dok-do island were developed since ca. 7,000 yr. BP, when sea level raised almost to the present level. The average extension speed of shore platform was calculated to 4.0mm/y, because the broadest shore platform with the width ca. 28m was extended for ca. 7,000 years. The width's dimension of shore platform at Dok-do reflects a slow extension rate in the present, although erosional process will be faster with the sea level rise in the future.