• 한국초지조사료학회지
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• 제36권3호
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• pp.223-236
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• 2016

The objective of this study was to construct Italian ryegrass (IRG) dry matter yield (DMY) estimation models in South Korea based on climatic data by locations. Obviously, the climatic environment of Jeju Island has great differences with Korean Peninsula. Meanwhile, many data points were from Jeju Island in the prepared data set. Statistically significant differences in both DMY values and climatic variables were observed between south areas of Korean Peninsula and Jeju Island. Therefore, the estimation models were constructed separately for south areas of Korean Peninsula and Jeju Island separately. For south areas of Korean Peninsula, a data set with a sample size of 933 during 26 years was used. Four optimal climatic variables were selected through a stepwise approach of multiple regression analysis with DMY as the response variable. Subsequently, via general linear model, the final model including the selected four climatic variables and cultivated locations as dummy variables was constructed. The model could explain 37.7% of the variations in DMY of IRG in south areas of Korean Peninsula. For Jeju Island, a data set containing 130 data points during 17 years were used in the modeling construction via the stepwise approach of multiple regression analysis. The model constructed in this research could explain 51.0% of the variations in DMY of IRG. For the two models, homoscedasticity and the assumption that the mean of the residuals were equal to zero were satisfied. Meanwhile, the fitness of both models was good based on most scatters of predicted DMY values fell within the 95% confidence interval.

• Parasites, Hosts and Diseases
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• 제49권3호
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• pp.309-311
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• 2011

Seroepidemiological status of toxoplasmosis among the residents of Jeju island was surveyed and evaluated by ELISA with crude extract of Toxoplasma gondii. The sera of 2,348 residents (male 1,157 and female 1,191) were collected and checked for the IgG antibody titers, which showed 13.2% positive rate (309 sera). The positive rates were increasing gradually according to the age from 4.3% in teenage to 20.6% in seventies. The positive rates were significantly different between the sex by 16.2% for male and 10.2% for female (P<0.05). This positive rate of toxoplasmosis in Jeju island residents is regarded relatively higher than any other regions of Korea. And the high positive rate may be maintained continuously among Jeju island residents without any clear reasons until now but due to some parts peculiar socio-cultural tradition of Jeju island. Therefore, it is necessary to study further the epidemiology of toxoplasmosis of Jeju island.

• 대한토목학회논문집
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• 제43권2호
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• pp.207-218
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• 2023

제주도는 국내 항공교통의 약 90 %를 차지하는 주요 기종점이며, 연간 천만명 이상의 국내외 관광객이 방문하는 주요 관광지이다. 국내 외 제주도 방문객의 공항 및 항공 여건에 대한 만족도, 요구사항, 그리고 제주도 내에서의 관광을 위한 여객 통행행태는 제주도 내는 물론 내륙의 항공 및 관광, 모빌리티 산업에 의미하는 바가 크다. 본 연구는 선행연구와 달리 내국인 방문객 뿐만 아니라 외국인 방문객과 거주민을 포함한 설문조사를 바탕으로, 전술한 바와 같은 의의를 지니는 제주 관련 여객 통행행태를 제시하고자 하였다. 특히 본 연구를 위해 수행한 설문조사는 2019년 3월 이루어져, 2020년 초 COVID-19 대응 방역지침 이전에 수행된 조사로서, COVID-19 전/후의 제주도 관광여객통행 및 항공통행 변화의 주요한 사전 연구가 될 것으로 기대된다. 한편, 본 연구가 3월에 수행되어 시기적 특성을 반영하지 못한다는 점, 국내선 이용량이 압도적으로 많아 국제선에 대한 별도의 내용을 제시하고 있지 못하다는 점은 한계에 해당한다.

• 한국태양에너지학회 논문집
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• 제35권3호
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• pp.57-63
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• 2015

This paper presents a solution by introducing energy storage system(ESS) to solve an annual blackout due to a typhoon or electrical failure in Udo Island. This island is now receiving electrical power through undersea cables from the Jeju Island. During blackout period, ESS will supply the electricity. And it is necessary to estimate the ESS capacity and control the transient state for the operation of stable power system. For the verification of proposed method, ESS capacities have been estimated according to base load and the minimum capacity of only home appliance in Udo Island. Also, in case of restoring from the fault, the algorithm for synchronization is proposed. Finally, the simulation results by using the PSCAD/EMTDC program will show the feasibility.

• 한국환경과학회지
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• 제27권7호
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• pp.555-560
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• 2018

This study conducted to analyze the growth characteristics of old Prunus yedoensis on Jeju island. The diameter growth per year was measured using a DTRS-2000 instrument. The DBH, ground DBH and height of the investigated P. yedoensis were 137 cm, 143 cm, and 15.5 m, respectively. Our analysis showed that the age of the old P. yedoensis was 93 years. An annual diameter growth of $2.85mm{\pm}0.96$ was observed. The result of age estimation, about $265{\pm}64$ years in P. yedoensis on Jeju island. This information could be useful to understand the annual diameter growth characteristics the P. yedoensis distributed on Jeju island.

• 전기학회논문지
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• 제60권12호
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• pp.2183-2189
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• 2011

Since main portion of the required electric power in Jeju Island is provided from the mainland through two HVDC lines, Jeju HVDC has a most significant impact on Jeju power system. Average wind speed of Jeju Island is the highest among several candidates in South Korea. So, Jeju Island has been a suitable site for the construction of wind farms where several wind farms are now operating and several others to be sited. Since the large-scale wind generation could have adverse impacts on the stable operation of Jeju power system, wind power is also important for the stability of Jeju power system. Therefore, accurate modeling of Jeju HVDC and wind farms is required for stability analysis of Jeju power system. In this paper, PSS/E-based dynamic modeling of Jeju HVDC and DFIG wind farms is proposed. Model-writing technique of PSS/E is used to develop USRAUX model and USRMDL model for controlling the frequency of HVDC and imposing an operation limit of wind power, respectively. Dynamic characteristics of Jeju HVDC and DFIG wind farms are analyzed through the dynamic simulations. The simulation results show the effectiveness of the developed models for Jeju power system.

• 한국임상수의학회지
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• 제31권3호
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• pp.206-211
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• 2014

Anaplasmosis 은 흡혈성 절지동물인 진드기, 이파리, 모기 등에 의해 매개되는 리케차성 인수공통 전염병이다. 철새는 anaplasmosis의 매개체인 진드기의 숙주이다. 제주도의 다양한 철새 분류군 중에서 지빠귀과 조류의 진드기 감염률이 높다. 특히 마라도는 봄철 남방구에서 북방구로 이동하는 철새의 중간기착점으로 지리적으로 중요한 위치에 있다. 따라서 본 연구에서는 제주도의 대표적 이동철새인 지빠귀과 새들의 Anaplasma spp. 감염여부를 조사하였다. 우리는 마라도에서 34마리의 혈액과 제주야생동물구조센터에서 구조 채취된 6개의 혈액 시료를 대상으로 하였다. 그 결과, 40개체의 지빠귀 중 7개체가 감염이 확인되었으며, 감염률은 17.5%로 나타났다. 7개체 모두 Anaplasma phagocytophilum으로 동정되었다. 이러한 결과는 제주도를 통과하는 대표적인 철새인 지빠귀과 새들이 A. phagocytophilum을 육지로 전파할 수 있음을 시사하며, 다른 이동성 철새들간의 질병전파의 보균자로 작용할 수 있기에 철새, 텃새 및 가축으로의 전파여부를 지속적으로 모니터링할 필요가 있다.

• 한국지하수토양환경학회지:지하수토양환경
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• 제25권3호
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• pp.1-11
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• 2020

In this study, leakage ratios of Jeju Island's public agricultural groundwater were calculated by utilizing field measurements of groundwater level and surface reservoir water level. The average leakage ratios were 75.6% at groundwater well A and 57.5% at well B, with the ratio inversely proportional to agricultural water usage. The level of agricultural reservoirs varied at constant intervals at night, and the amount of water leakage associated with the variation was estimated as 0.1 - 16.3 ㎥/h. The leakage ratio was also influenced by pipeline length, average slope, and number of farmhouses. Currently, the estimation of agricultural water leakage on Jeju Island is based upon field inspection which is very labor- and cost intensive. The leakage ratio estimated by monitoring the reservoirs associated with the well A and B were 73.3 and 54.7%, respectively, consistent with the values obtained by field measurements.

• 한국생물공학회:학술대회논문집
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• 한국생물공학회 2005년도 생물공학의 동향(XVII)
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• pp.899-903
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• 2005

Two infectious species of Streptococcosis pathogens were detected by multiplex PCR assay. Detection rates of Streptococcus iniae and S. parauberis could reach 44.9% and 55.1% respectively for one year during 2004 to 2005 in Jeju island. These findings showed that S. parauberis strains were important pathogen with streptococcosis of olive flounder in Jeju island. These findings showed that S. parauberis strains were important pathogen with streptococcosis of olive flounder in Jeiu island. In the present study we have investigated the interspecific relationship of all Jeju area of S. parauberis by RAPD analysis. Represent strains divided to four groups by RAPD fingerprints. The important differences observed between the olive flounder isolates suggest that they could constitute a well-differentiated group or a separate clonal line within this bacterial species. Though, serological research of S. parauberis strains in Jeju island not exist yet. These strains doing the serological evolution.

• 한국환경과학회지
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• 제25권12호
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• pp.1727-1738
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• 2016

In this study, groundwater flow was analyzed targeting Dae-jeong watershed, which exhibited the largest variations of groundwater levels at the identical elevation points among the 16 watersheds of Jeju Island. The issues of the methods applied in practice were identified and improvement plans were suggested. This groundwater-flow estimates derived by applying hydraulic conductivity values onto zones of equal topographic ground level were found to be quite different from actual measured groundwater flow. Conversely, groundwater-flow estimates that utilized hydraulic conductivity values applied onto groundwater-level equipotential lines indicated relatively lesser divergences from actual measured groundwater flow. The reliabilities of the two approaches were assessed for 60 randomly selected points on DEM (digital elevation model) maps, The method using hydraulic conductivity values applied onto groundwater-level contours turned out to be the more reliable approach for the Dae-jeong watershed in Jeju Island.