• Journal of Wind Energy
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• v.9 no.4
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• pp.40-46
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• 2018

In this study, a three-dimensional Navier-Stokes simulation around Wido Island was performed to analyze the wake effect behind an island. A 10 m/s wind speed and pressure boundary conditions were assigned for the inflow and outflow boundary conditions, respectively. Wido Island was modeled using GIS data. A prevailing wind from the north-northwest direction was determined based on QuikSCAT satellite data. A computational domain of $40km{\times}20km{\times}5km$ covering Wido Island was applied for numerical analysis. Sixty points were specified to extract the wind speed data. A wind speed profile inside the atmospheric boundary layer was compared with a wind profile using a simple power law. It turns out that the wake effect decreases the mean wind speed by 5% more or less, which corresponds to a 14% decrease in wind energy. Thus, the installation of a meteorological mast or development of a wind farm behind Wido Island is not highly recommended.

• Journal of the Korean Geotechnical Society
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• v.31 no.7
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• pp.41-52
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• 2015

Volcanic rocks in Jeju Island have vesicular structure caused by various environmental factors, and indicate the differences in geological and mechanical characteristics from region to region. In addition, the bedrock of Jeju Island shows stratified structure, that is, soft layers composed of pyroclastic rocks or cavities are irregularly developed between the basalt layers by several times of volcanic activity. In this study, various physical tests and unconfined compressive strength test were conducted for intact rocks sampled in northwestern onshore and offshore of Jeju Island. The results obtained in the tests were compared with the physical and mechanical characteristics of intact rocks sampled in southeastern offshore of Jeju Island. As a results, it was confirmed that the physical and mechanical characteristics of basalts sampled in northwestern Jeju Island were similar to those of basalts sampled in southeastern offshore of Jeju Island. In addition, it was possible to estimate approximate design parameters from the correlation of mechanical properties with physical properties of basalts in Jeju Island.

• Health Policy and Management
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• v.13 no.3
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• pp.104-128
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• 2003

Equity in health care has taken priority in the Korean government's policy agenda after the government-led national health insurance achieved universal coverage in 1989 along with the final inclusion of the self-employed as beneficiary. The purpose of this study is to examine the extent to which there exists difference or inequality in the utilization of health care, especially cancer inpatient services among income classes. We analysed the utilization of cancer inpatient services of residents in Jeju Island for a year of 2000, using the national health insurance data for qualification of beneficiaries and utilization of health care. The independent variable are 10 income classes based on the national health insurance fee imposed on each household for a year of 2000. The dependent variables of this study are an amount of cancer inpatient health care utilization measured by cancer admission days and cancer treatment costs. Also, cancer inpatient health care utilization is analysed by three categories divided into utilization in medical care institutions (1) within Jeju Island, (2) outside Jeju Island, and (3) all within and outside Jeju Island. We measured concentration index of cancer inpatient health care utilization. This analysis showed negative concentration index within Jeju Island and positive outside Jeju Island, and positive in all within and outside Jeju Island. This results suggest inequality against the relatively poor income groups in utilization of cancer inpatient health care services. Especially, inequity of cancer inpatient health care would be more serious in Jeju Island of Korea, considering that lower income groups reportedly have higher incidence rates in most of cancer and thus use more health services.

• The Korean Journal of Ecology
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• v.7 no.3
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• pp.132-157
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• 1983

This study was performed to investigated the flora and vegetation of Kokum-do island from July 1982 thru December 1983; and the findings hereof are summarized as follows: The flora investigated thereform comprises 737 species whih are classified into 128 families, 466 genera, 651 species, 79 varieties and 7 formae; and those which are worthy of close attention among the same include such endemic species of Korea as Celtis choseniana, Corylopsis coreana, Carpinus tschonoskii var. eximia and Tricyrtis dilatata, and a few plants, to be distributed in the north, such as Lilium distichum, Girardinia cuspidata and Orostachys sikokianus. Now that the said island belongs to the warm temperate zone, the distribution thereof consists of 120 species of evergreen plants including 74 species of evergreen broadleaf trees. The rich distribution of evergreen broadleaf trees in the island is thanks to the plantation thereof by the public organizations for scenic beauty. The destruction of flora in this island was caused by felling, fire nization and other human activities around 1940, and in particular, has been correlated with the population densiity of Yonhong-do, Sanghwa-do, and Hahwado islets; and that of top soil and ground vegetation in he quarry area of Ojon-ri town resulted from the collection of natural rocks an stones. It is evaluated as necessary that such evergreen broadleaf trees as Castanopsis cuspidata var. thunbergii, Machillus thunbergii and Ligustrum japonicum of Hyongje-do. Chun-do, Tok-do, Taech'wi-do, and Soch'wi-do islets, andPhyllostachys bambusoides, Caesalpinia japonica and Albizzia julibirssin of Kokum-do island, and Machillus thunbergii of Hongryon-ri town be under protection. The average DGN of the whole archipelago proves to be 5.84, which shows the tendency of the inverse proportion to the number of resident population per unit area. The pteridophyta distributed in this island comprises 39 species, and the coefficient of cryptogam as to the destruction of vegetation shows a high value of 1.4 which is regarded as indicating the diversified distribution of pteridophyta, forestbed shade plants under the forestbeds of some wellpreserved lots of this island. The naturalized plants, distributed in this island, were found out comprising a total of 23 species, and the Urbanization Index(UI) as to the destruction degree of natural vegetatioin shows a low value of 20.9.

• Atmosphere
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• v.29 no.4
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• pp.381-390
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• 2019

This study investigates the impacts of urban land-use fraction and temperature advection on the urban heat island intensity over the Seoul metropolitan area using the UM (Unified Model) with the MORUSES (Met Office Reading Urban Surface Exchange Scheme) during the heat wave over the region from 2 to 8, August 2016. Two simulations are performed with two different land-use type, the urban (urban simulation) and the urban surfaces replaced with grass (rural simulation), in order to calculate the urban heat island intensity defined as the 1.5-m temperature difference between the urban and the rural simulations. The land-use type for the urban simulation is obtained from Korea Ministry of Environment (2007) land-use data after it is converted into the types used in the UM. It is found that the urban heat island intensity over high urban-fraction regions in the metropolitan area is as large as 1℃ in daytime and 3.2℃ in nighttime, i.e., the effects of urban heat island is much larger for night than day. It is also found that the magnitude of urban heat island intensity increases linearly with urban land-use fraction. Spatially, the estimated the urban heat island intensities are systematically larger in the downwind regions of the metropolitan area than in the upwind area due to the effects of temperature advection. Results of this study indicate that urban surface fraction in the city area and temperature advection play a key role in determining the spatial distribution and magnitude of urban heat island intensity.

• Journal of the Korean association of regional geographers
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• v.19 no.2
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• pp.223-233
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• 2013

Yeonpyeong Island, an island of Ong-jin County, is a very important and meaningful area in terms of its geo-politics and natural environment. But in spite of well preserved natural environment, because of limited access and security risk, there were little researches. In this sense this study would be meaningful for inquiring into the regional geomorphology of Yeon-pyeong Island. The major findings of this study are as follows. 1) 12 sites among 20 sites was evaluated 1st grade, and this means that geomorphic value of Yeon-pyeong Island is very excellent. 2) Coastal landforms of Yeon-pyeong Island are classified three major types which are rocky coast which consist of wave-cut platform and sea cliffs, sand or shingle beaches and coastal plain in the embayment area, and tidal flat areas and small uninhabited islands. 3) Cross sectional shape of Yeon-pyeong Island is asymmetric, since coastal erosion of island concentrate on the northern and western shore. 4) Quality and value of tidal flats will be deteriorate unless the dyke construction is stopped.

• Journal of Korean Society of Transportation
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• v.23 no.5 s.83
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• pp.73-81
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• 2005

Triangle-shaped island was been used for the exclusive separation between the right-turn and the through flow. However, in case that existing Triangle-Shaped Island is built at the intersection of narrow road. there are more possibilities of traffic collision trespassing into the opposite lane. Accordingly, separation of the opposite lane is required so as to prevent the intrusion of the large-sized (a heavy) vehicle into the opposite lane turning at the intersection. This study showed the comparison between intersection composed of existing Triangle-Shaped Island and the intersection with Drop Island is added. First of all, in the safety aspect, a method to decide location and shape of Drop Island considering turning trajectory of the large-sized (the heavy vehicle) is addressed. The guideline on the placement of drop island install location and method to decide form the consider heavy truck's turn trajectory in safety side. As a conclusion. we analyzed that drop island is relatively superior to existing Triangle-Shaped Island in terms of driver, ease of driving, driving pleasantness, pedestrian, widening and economic performance aspect.

• The Korean Journal of Ecology
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• v.22 no.6
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• pp.325-335
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• 1999

Empetrum nigrum dominant community or Rhododendron mucronulatum and R. yedoense var. poukhanense dominant shrub community are developing above l,500m on Mt. Halla in Cheju Island, Korea. These communities were formed as a result of the forest of Abies koreana regression by grazing or erosion over a long period of time. This study was conducted using the phytosociological method and it clarified the floristic composition of the community in Cheju Island by comparing with a similar community in Japan. Also this study interpreted the development data of these communities and considered community succession. As a result of our interpretation, shrub community of Cheju Island is recognized as two associations, Festuco obinae-Empetretum nigrum ass. nov and Rhododendretum mucronulatum ass. nov. Each association of Cheju Island is composed of endemic species of Cheju Island. related to the Korean peninsula and to Japan. The two associations are divided into 8 sub-units but each community development has been created with longtime grazing and prescribed fire. Maybe the location stability by stoppage of interference and grazing will process community transition Quickly. Comparing the shrub communities of Cheju Island with Maianthemo-Rhododendretum in Kyushu, Japan, which is close geographically, both areas have the species of Miscanthetea sinesis and Ericaceae in common. But Cheju Island has more abundant species and has higher ratio of appearance of alpine plants. The shrub communities of Cheju Island and Kyushu. Japan are identified as having a different rank over Alliance.

• Archives of Reconstructive Microsurgery
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• v.12 no.1
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• pp.38-43
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• 2003

Purpose : Various free flaps and pedicled island flaps are effective for reconstruction of soft tissue defect developed after tumor excision. We want to know the advantage of dorsalis pedis island flap for reconstruction of soft tissue defect caused by soft tissue tumor excision. Materials and Methods : Between 1992 and 2002, we performed 4 dorsalis pedis island flap procedure for reconstruction of soft tissue defect of lower limb developed after soft tissue tumor excision. Average age was 54.7 years old $(40{\sim}68)$, and male 2 cases, female 2 cases. The kinds and number of soft tissue tumors were 2 squamous cell carcinoma and 2 malignant melanoma. The procedures that we performed were all dorsalis pedis island flap. The analysis for the result of treatment was retrospectively accessed by physical examination and questionnaire for whether the change of symptom after operation, range of adjacent joint motion. Also we reviewed associated complication after operative treatment. Results : All dorsalis pedis island flaps were alive. There is no problem for activity of daily living, no skin necrosis and no limitation of motion of adjacent joint. In 1 case of them, the patients died of distant metastasis. Conclusion: Dorsalis pedis island flap procedure as a pedicled island flap procedure is very effective and easy operative procedure for reconstruction of soft tissue defect of lower limb developed after tumor excision compared to free flap procedure because there is no need for microvascular surgery, we can obtain relatively large flap and the lesion and flap donor site locate in the same limb.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.65 no.7
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• pp.1236-1241
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• 2016

Cancer has been the most frequent in Korea, and pathogenesis and progression of cancer have been known to be occurred through various causes and stages. Recently, the research of chromosomal and genetic disorder and the research about prognostic factor to predict occurrence, recurrence and progress of chromosomal and genetic disorder have been performed actively. In this paper, we analyzed DNA methylation data downloaded from TCGA (The Cancer Genome Atlas), open database, to research bladder cancer which is the most frequent among urinary system cancers. Using three level of methylation data which had the most preprocessing, 59 candidate CpG island were extracted from 480,000 CpG island, and then we analyzed extracted CpG island applying data mining technique. As a result, cg12840719 CpG island were analyzed significant, and in Cox's regression we can find the CpG island with high relative risk in comparison with other CpG island. Shown in the result of classification analysis, the CpG island which have high correlation with bladder cancer are cg03146993, cg07323648, cg12840719, cg14676825 and classification accuracy is about 76%. Also we found out that positive predictive value, the probability which predicts cancer in case of cancer was 72.4%. Through the verification of candidate CpG island from the result, we can utilize this method for diagnosing and treating cancer.