• Parasites, Hosts and Diseases
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• v.49 no.3
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• pp.317-321
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• 2011

Adult gnathostomes were discovered in the stomach of the Jeju weasel, Mustela sibilica quelpartis, road-killed in Jeju-do (Province). Their morphological characters were examined to identify the species. Total 50 gnathostome adults were collected from 6 out of 10 weasels examined. In infected weasels, 4-6 worms were grouped and embedded in each granulomatous gastric tumor, except 1 weasel. Male worms were $25.0{\times}1.4$ mm in average size, and had a tail with pedunculate papillae, a spicule, and minute tegumental spines. Females were $40.0{\times}2.5$mm in average size, and had a tail without tegumental spines. Pointed and posteriorly curved hooklets were arranged in 8-10 rows on the head bulb. Tegumental spines were distributed from behind the head bulb to the middle portion of the body. The spines were different in size and shape by the distribution level of the body surface. Fertilized eggs were $65.5{\times}38.9\;{\mu}m$ in average size, and had a mucoid plug at 1 pole. These gnathostomes from Jeju weasels were identified as Gnathostoma nipponicum Yamaguti, 1941. By the present study, it was confirmed for the first time that G. nipponicum is distributed in Jeju-do, the Republic of Korea, and the Jeju weasel, M. sibilica quelpartis, plays a crucial role for its definitive host.

• Journal of Ecology and Environment
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• v.29 no.2
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• pp.85-103
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• 2006

An investigation of fauna and community of insects in Gotjawal Terrain, Jeju-do, had been conducted with a way of black light trap from July to September, 2005. The investigated insects were classified into 217 species, 75 families, and 11 orders respectively. Coleoptera that occupied 55.3 percent among them and was consisted of 120 species was the richest group and Hemiptera followed it. The density of Physopelta gutta was highest but Physopelta cincticollis was overall the dominant species in all sampling areas. The species diversity index was highest at Jocheon-Hamdeog Gotjawal in Jeju-do, while it was lowest in Gujwa-Sungsan Gotjawal. Clustering analysis revealed that the insect communities of four localities were grouped in only one cluster. Included in the species unreported in Jeju Island were Menida musiva and Pentatoma japonica in Hemiptera, Philonthus wuesthoffi in Coleoptera, and Phanerotoma flava in Hymenoptera.

• Parasites, Hosts and Diseases
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• v.60 no.5
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• pp.327-338
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• 2022

This study determined the recent status and trend of Pneumocystis jirovecii pneumonia (PcP) in the non-human immunodeficiency virus (HIV) (non-HIV-PcP) and HIV (HIV-PcP) infected populations using data from the Health Insurance Review & Assessment Service (HIRA) and the Korea Disease Control and Prevention Agency (KDCA). SaTScan and Join-point were used for statistical analyses. Non-HIV-PcP cases showed an upward trend during the study period from 2010 to 2021, with the largest number in 2021 (551 cases). The upward trend was similar until 2020 after adjusting for the population. Seoul had the highest number of cases (1,597) in the non-HIV-PcP group, which was the same after adjusting for the population (162 cases/1,000,000). It was followed by Jeju-do (89 cases/1,000,000). The most likely cluster (MLC) for the non-HIV-PCP group was Seoul (Relative Risk (RR)=4.59, Log Likelihood Ratio (LLR)=825.531), followed by Jeju-do (RR=1.59, LLR=5.431). An upward trend was observed among the non-HIV-PcP group in the Jeju-do/Jeollanam-do/Jeollabuk-do/Gyeongsangnam-do/Busan/Daejeon/Daegu/Ulsan joint cluster (29.02%, LLR=11.638, P<0.001) located in the southern part of Korea. Both women and men in the non-HIV groups showed an overall upward trend of PcP during the study period. Men in the 60-69 age group had the highest annual percentage change (APC 41.8) during 2014-2019. In contrast, the HIV groups showed a falling trend of PcP recently. Men in the 60-69 age group had the most decrease (APC -17.6) during 2018-2021. This study provides an analytic basis for health measures and a nationwide epidemiological surveillance system for the management of PcP.

• Fisheries and Aquatic Sciences
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• v.24 no.6
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• pp.228-234
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• 2021

A single specimen (39.4 mm standard length) of Brachaluteres ulvarum, belonging to the family Monacanthidae has been recorded for the first time from Supseom, Jeju-do Island of southern Korea on 6 March 2021. This species was characterized by the presence of a small second dorsal spine present, the posterior end of pelvic without encasing scales, and numerous thin dark longitudinal lines on body. It was morphologically similar to the B. taylori, but distinguished by the ratio of the caudal peduncle to the head length (B. ulvarum, 2.5 to 3.7 times; B. taylori, 3.5 to 5.2 times). In addition, the former is well distinguished from the latter through mitochondrial cytochrome c oxidase subunit I (COI) sequences by genetic distances of range from 0.088 to 0.090. The new Korean name "Kko-ma-jwi-chi- sog" is proposed for the genus Brachaluteres, and "Kko-ma-jwi-chi" for the species B. ulvarum.

• Journal of Electrical Engineering and Technology
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• v.10 no.1
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• pp.47-55
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• 2015

This paper proposes the installation of a new modular multilevel converter based high-voltage direct current (MMC-HVDC) system to connect between mainland and Jeju island power systems in Korea in 2020. The purpose is to combine with two old line-commutated converters (LCC)-based HVDC system to achieve a stability of the Jeju island power system. The operation of the overall system will be analyzed in three cases: (i) wind speed is variable, (ii) either one of the LCC-HVDC systems is shutdown because of a fault or overhaul, (iii) a short circuit fault occurs at the mainland side. The effectiveness of the proposed control method is confirmed by the simulation results based on a PSCAD/EMTDC simulation program.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.56 no.6
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• pp.909-915
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• 2023

A specimen of longarm mullet Moolgarda cunnesius (Valenciennes, 1836) belonging to the family Mugilidae was collected from Yerae-dong, Seogwipo-si, Jeju-do Island, Korea, on July 19, 2023, using a hand net. The specimen was identified as Moolgarda cunnesius based on its morphological traits, including pectoral fin reaching the third or fourth spine of the first dorsal fin, anal fin higher than the first and second dorsal fin, two dorsal and caudal fin membranes with small melanophores, and a slightly convex interorbital region. Furthermore, molecular analysis, specifically comparison of the 623 base pairs of mitochondrial DNA COI sequences, confirmed that our specimen perfectly matched M. cunnesius. It is well known that the species is widely distributed in the Indo-West Pacific Ocean, including the Red Sea, Taiwan, and northern Australia, and this study shows that it also inhabits the Jeju-do Island, Korea. Additionally, we propose a new Korean name 'gin-pal-sung-eo' for this species.

• 한국신재생에너지학회:학술대회논문집
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• 2010.06a
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• pp.235.2-235.2
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• 2010

In this study, the wave power resources at the southern sea of Korea were estimated by using the hindcasted wave data of previous researches. The used data were wave heights, periods and directions which were hindcasted around the Korea peninsular from 1979 to 2003. The spatial resolution of the hindcasted data is $1/6^{\circ}$(about 18 km). In winter, the northwest monsoon increase the wave power, while the wave power around Korea peninsular is very small in spring. The maximum value of the annual mean wave power is about 13 kW/m at Gageo-do, Heuksan-do and western region of Jeju-do, while those at the southern sea of Korea is only 4 kW/m, which is relatively small. The wave power at Korean east sea is lower than that of Korean southern sea. We obtained the wave resources information, in a fine grid, at Gageo-do, Heuksan-do, and western sea of Jeju-do, by solving SWAN model with the boundary conditions of hindcasted wave data.

• Korean Journal of Plant Taxonomy
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• v.51 no.4
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• pp.363-371
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• 2021

Vicia bifolia Nakai (Fabaceae) and Cyperus compressus L. (Cyperaceae) have been ambiguous in terms of their distribution and taxonomic entities in Korea. The existence of these two taxa was confirmed when V. bifolia and C. compressus was found on Jellabuk-do, Gyeongsangnam-do, and Jeju-do. Vicia bifolia is similar to V. unijuga by having a pair of leaflets but is distinguished by the length of the petiole, the size and degree of longevity of the bracts, and the shape of the stipules. Cyperus compressus was found on Jeju-do, is similar to C. tenuispica, C. haspan, and C. flaccidus, but is distinguished by the branching pattern of the inflorescences and the size of scales and achenes. A description, differences from related species, a key to the taxa and photographs of Korean Vicia bifolia and Cyperus compressus are provided in this study.

• ALGAE
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• v.19 no.3
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• pp.235-245
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• 2004

A study on seasonal characteristics of phytoplankton dynamics and environmental factors was carried out at four stations including Mara-do and U-do located in the western and eastern coast of Jeju Island in southern Korea from April 2003 to March 2004. Out of 101 phytoplankton species identified, 84 belong to Bacillariophyceae, 9 Dinophyceae, 6 phytoflagellates and 2 coccolithophorids, and the highest value of species diversity was observed in April. Phytoplankton was more abundant at the western coast than at the eastern coast from March to September and its highest abundance was 49.24 ${\times}$ 10$^3$ cells L$^{-1}$ at Mara-do in July. The pennate diatoms were more abundant at the western coast than at the eastern coast with the highest abundance of 38.75 ${\times}$ 10$^3$ cells L$^{-1}$ at Mara-do in July, and during this period Nitzschia longissima contributed 68.5% of the total phytoplankton abundance. Naviculaceae was more abundant at Gosan (western coast) in November when Stauroneis membranacea represented 80.1% of the abundance. Leptocylindrus dances contributed 49.4% of the abundance at U-do in November. Dinophyceae was more abundant at U-do in August. Water temperature and pH fluctuated from 11.7${^{\circ}C}$ to 27.1${^{\circ}C}$ and from 7.31 to 8.70, respectively. Water temperature of Mara-do was about 1-2${^{\circ}C}$ higher than the other stations. Salinity varied from 30.4 to 35.0 psu with the minimum in rainy season and the maximum at the end of winter. The concentration of NH$_4$-N, NO$_3$-N, NO$_2$-N, PO$_4$-P and SiO$_2$-Si ranged 0.07-6.79, 1.0-62.0, 1.0-8.0, 1.0-7.0 and 7.0-191.0 $\mu$g-at L$^{-1}$, respectively. Chlorophyll a concentrations varied from 0.10 to 1.17 $\mu$g L$^{-1}$. NH$_4$-N concentrations were high at U-do from May to December, and at Mara-do from January to February. The high concentrations of NO$_3$-N were found at Mara-do from June to September and at U-do from January to May. The effects of various physicochemical parameters on the seasonal distribution and succession of phytoplankton population suggest that there is a classical pattern of phytoplankton dynamics in Jeju coastal waters.

• The Korean Journal of Malacology
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• v.25 no.3
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• pp.231-236
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• 2009

This study describes biological environmental characteristics in natural habitats of Haliotis diversicolor in the coastal area of Sungsanpo located in the eastern coast of Jeju-do, Korea. The field survey was monthly conducted from May 2006 to February 2007. H. diversicolor, sea urchin, turban shell and marine algae were collected by two divers using SCUBA. The species composition of demersal fishes were seasonally investigated by fish traps in 2007. During the study period, more than 67% of H. diversicolor and sea urchin were found in the depth shallower than 5 m, and more than 64% of turban shell were found in the depth deeper than 3 m. The dominant algal species in May were generally Undaria pinnatifida, Ecklonia cava, Sargassum. spp. and coralline algae. Most of demersal fishes collected by the fish traps were wrasses which have been reported as a major predator of young abalone.