• Journal of Climate Change Research
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• v.4 no.3
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• pp.221-233
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• 2013

Due to the fact that the speed of climate change in Republic of Korea exceeds the global average speed, sound conservation and tourism strategies should be prepared based on the comparison between the meteorological factors and the number of tourists. In this context, almost 70 percent of the industries in Ulleung-do are closely related to tourism; hence the significance of tourism is increasing. The annual precipitation variation does not show remarkable fluctuation, and most precipitation has a tendency to fall in summer and autumn However, for the years 2010 and 2011, a different trend was exhibited with higher winter precipitation than any other periods. Precipitation intensity is usually stronger in May (in the morning), June (in the afternoon), and no big difference is shown between morning and afternoon precipitation from July to September. The number of tourist is compared to both the precipitation at Ulleung-do and the number of advisories and warnings in the East Sea of Korea using correlation analysis. The results demonstrate that the meteorological factors that reduce the number of tourist are precipitation and the number of advisories and warnings.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.11 no.1
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• pp.21-30
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• 2006

This study investigated the temperature-salinity spatio-temporal variability around the Ulleung-do Island (UI) by using CTD profiles obtained by the ARGO floats far the period of Oct.,2003 to Aug.,2005. The waterbody in the upper 700 m around the UI could be classified into five water masses, which is consistent to traditional water characteristics in the East Sea. In the upper surface layer, the temperature and salinity in fall season became even lower than those properties in the summer time. The East Sea Intermediate Water (ESIW) characterized by the salinity minimum layer shows the range of potential temperature between 1 to $5^{\circ}C$ and salinity lower than 34.06 psu. The ESIW lies approximately at 265 m depth with average thickness of 175 m. This thickness of the ESIW continues to be relatively uniform regardless of spatio-temporal space. However, the depth of the ESIW shows vertical variation influenced by the Ulleung warm eddy (UWE). Since the UWE lies in the upper layer, the Upper Portion of the Japan Sea Proper. Water (UPJSPW) is also affected to show the vertical variation. The influence extorted by the UWE reached down to 700 m depth in terms of temperature. The CTD profiles obtained with the high sampling rate by ARCO floats over two-year period provided with very useful and detailed informations in investigating the spatio-temporal variability In the study area.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.14 no.3
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• pp.127-133
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• 2009

In order to determine organic carbon oxidation by manganese and iron oxides, six core sediments were obtained in slope and basin sediments of Ulleung Basin in East Sea. The basin sediments show high organic carbon contents (>2%) at the water depths deeper than 2,000 m; this is rare for deep-sea sediments, except for those of the Black Sea and Chilean upwelling regions. In the Ullleung Basin, the surface sediments were extremely enriched by Manganese oxides with more than 2%. Maximum contents of Fe oxides were found at the depth of $1{\sim}4cm$ in basin sediments. However, the high level of Mn and Fe oxides was not observed in slope sediment. Surface manganese enrichments (>2%) in Ulleung Basin may be explained by two possible mechanisms: high organic carbon contents and optimum sedimentation rates and sufficient supply of dissolved Manganese from slope to the deep basin. Reduction rates of iron and manganese oxides ranged from 0.10 to $0.24\;mmol\;m^{-2}day^{-1}$ and from 0.30 to $0.57\;mmol\;m^{-2}day^{-1}$, respectively. In Ulleung Basin sediments, $13{\sim}26%$ of organic carbon oxidation may be linked to the reduction of iron and manganese oxides. Reduction rates of metal oxides were comparable to those of Chilean upwelling regions, and lower than those of Danish coastal sediments.

• Journal of the Korean Geophysical Society
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• v.2 no.1
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• pp.9-26
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• 1999

The Ulleung Basin (Tsushima Basin) in the southwestern East Sea (Japan Sea) is floored by a crust whose affinity is not known whether oceanic or thinned continental. This ambiguity resulted in unconstrained mechanisms of basin evolution. The present work attempts to define the nature of the crust of the Ulleung Basin and its tectonic evolution using seismic wide-angle reflection and refraction data recorded on ocean bottom seismometers (OBSs). Although the thickness of (10 km) of the crust is greater than typical oceanic crust, tau-p analysis of OBS data and forward modeling by 2-D ray tracing suggest that it is oceanic in character: (1) the crust consists of laterally consistent upper and lower layers that are typical of oceanic layers 2 and 3 in seismic velocity and gradient distribution and (2) layer 2C, the transition between layer 2 and layer 3 in oceanic crust, is manifested by a continuous velocity increase from 5.7 to 6.3 km/s over the thickness interval of about 1 km between the upper and lower layers. Therefore it is not likely that the Ulleung Basin was formed by the crustal extension of the southwestern Japan Arc where crustal structure is typically continental. Instead, the thickness of the crust and its velocity structure suggest that the Ulleung Basin was formed by seafloor spreading in a region of hotter than normal mantle surrounding a distant mantle plume, not directly above the core of the plume. It seems that the mantle plume was located in northeast China. This suggestion is consistent with geochemical data that indicate the influence of a mantle plume on the production of volcanic rocks in and around the Ulleung Basin. Thus we propose that the opening models of the southwestern East Sea should incorporate seafloor spreading and the influence of a mantle plume rather than the extension of the crust of the Japan Arc.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.26 no.4
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• pp.327-342
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• 2021

The global coastal region is considered as a sink for atmospheric CO₂. Since most of the studies in the East Sea focused on the Ulleung Basin, the importance of coastal region for carbon cycle has been overlooked. In this study, we compared the biological pump and CO₂ absorption between the Ulleung Basin and coastal region by surface measurements of biological O₂ supersaturation (𝚫O₂/Ar) and partial pressure of CO₂ (fCO₂). Cold and less saline waters in the coastal regions were in contrast with a warm and saline water in the Ulleung Basin. The coastal waters near Samcheok and Pohang showed higher fluorescence, 𝚫O₂/Ar, and lower fCO₂ than those in the Ulleung Basin, indicating higher primary production and CO₂ absorption in the areas. The average net community production estimated by 𝚫O₂/Ar were 19 ± 6 and 60 ± 9 mmol O₂ m^-2d^-1 in the Samcheok and Pohang, respectively, 2-7 times higher than that of 8 ± 4 mmol O₂ m^-2d^-1 in the Ulleung Basin. Similarly, the average CO₂ flux between the seawater and atmosphere were -17.1 ± 8.9 and -25.8 ± 13.2 mmol C m^-2d^-1 in the Samcheok and Pohang, respectively, 4-5 times higher than that of -4.7 ± 2.5 mmol C m^-2d^-1 in the Ulleung Basin. In the Samcheok and Pohang, degrees of N₂ saturation were lower by 3% than that the ambient waters, suggesting the possibility of nitrogen fixation by primary producers.

• Journal of the Korean Geographical Society
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• v.16
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• pp.25-34
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• 1977

• Mycobiology
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• v.42 no.1
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• pp.79-81
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• 2014

From June to October 2012, severe outbreaks of rust disease on Solidago virgaurea var. gigantea were observed in 5 different regions of Ulleung-do, Korea. Typical rust symptoms appeared as yellow spots, uredinia on leaves, and massive urediniospores covering the entire plant. Severely infected plants became discolored and died. On the basis of its morphological and molecular characteristics, the causal agent was identified as Coleosporium asterum. This pathogen has been reported as rust disease on S. virgaurea in the Canada and United States. In Korea, rust disease on S. virgaurea var. gigantea was reported as Uromyces rudbeckia in 1992. To the best of our knowledge, C. asterum is a novel rust pathogen on S. virgaurea var. gigantea in Korea.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.59 no.12
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• pp.2190-2194
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• 2010

Wind power generation system (WPGS) of Ulleung Island causes frequency and voltage fluctuation due to wind speed variation during night time. Superconducting magnetic energy storage (SMES) system can overcome the fluctuations through the fast response time of energy charging and discharging. The SMES system should be connected to the terminal of the WPGS for frequency stabilization. To demonstrated the effectiveness of SMES system for power quality improvement, Ulleung Island power network was modeled in a real time digital simulator (RTDS). The RTDS-based simulation results of power quality improvement with SMES are investigated and discussed in detail.

• Journal of the Korean Geographical Society
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• v.41 no.5 s.116
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• pp.623-629
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• 2006

At present, 3 names about undersea features in the East Sea - Korean Plateau, Tsushima Basin, Syun-yo Bank - are listed on Gazetteer Any explanations are not given for registration of these names. Just it seems that the names written on International marine chart(INT 511) were recorded to Gazetteer. Furthermore Tsushima Basin and Syun-yo Bank have no oceanographic, geologic reason and geographical relevance, and the names should be replaced by Ulleung Basin and Isabu Tablemount, respectively, that is deeply related to geographical relevance and genetic origin.

• Journal of the korean society of oceanography
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• v.38 no.4
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• pp.157-165
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• 2003

In order to understand the characteristics of sedimentary environments in Ulleung Basin of the East Sea (Sea of Japan), three sediment cores were taken with a box corer during R/V Tamyang cruise in October 1999. Activities of $^{7}Be,{\;}^{210}Pb,{\;}^{226}Ra,{\;}^{234}Th,{\;}^{238}{\;}and{\;}^{137}Cs$ in sediment samples were determined by non-destructive gamma-ray spectrometry. Rates of sedimentation and particle mixing were estimated by best fitting an advection­diffusion particle mixing model to the data of $^{7}Be,{\;}^{234}Th,{\;}and{\;}^{210}Pb$. Estimated sedimentation rates were 0.06-0.08 cm/yr and particle mixing rates were $0.13-0.65{\;}\textrm{cm}^2/yr$. The use of multiple tracers in our study prevented us from probable up to 38% overestimation of sedimentation rates.