• 제목/요약/키워드: jeju

검색결과 9,666건 처리시간 0.047초

New records of genus Tripos (Dinophyceae) around Jeju Island, Korea

  • Lee, Joon-Baek;An, So-Jeong;Chung, Han-Sik;Shah, Md. Mahfuzur Rahman
    • Journal of Ecology and Environment
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    • 제37권4호
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    • pp.271-284
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    • 2014
  • The morphology of 26 species of the genus Tripos was studied among a total of 51 species of this genus, which were taken using $20{\mu}m$ net samples from June 2006 to January 2011 at 14 stations around Jeju Island. Of these, 23 species were first described as new records in Korean waters and 3 species were redescribed. Short descriptions and synonyms are given for each species in the present study. The dinoflagellates of family Ceratiaceae include marine and freshwater species, belonged to originally the genus Ceratium. Recently, this genus were divided into a new combination with the genus Tripos, which contains the marine species, and the original genus Ceratium, including the freshwater species. We used the Tripos genus for the marine species in this study as a valid name.

Analyzing Stability of Jeju Island Power System with Modular Multilevel Converter Based HVDC System

  • Quach, Ngoc-Thinh;Lee, Do Heon;Kim, Ho-Chan;Kim, Eel-Hwan
    • Journal of Electrical Engineering and Technology
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    • 제10권1호
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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.

New Record of Dinoflagellates around Jeju Island

  • Kim, Hyeung-Sin;Kim, Seung-Hyun;Jung, Min-Min;Lee, Joon-Baek
    • Journal of Ecology and Environment
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    • 제36권4호
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    • pp.273-291
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    • 2013
  • Dinoflagellate species composition has changed around Jeju Island as well as in Korean waters due to global warming and climate changes. An investigation was conducted to monitor changes in planktonic dinoflagellates around Jeju Island from June 2006 to September 2009. A total of 86 species belonging to 14 families and 15 genera were identified, of which 34 species were newly recorded in Korean waters. Among the newly recorded species, >20 were confirmed as tropical species. Thus, the occurrence of such tropical dinoflagellates could be an indicator to monitor of environmental changes including global warming around Jeju Island and in Korean waters.

제주 송이를 이용한 견직물의 염색성 및 기능성 (Dyeability and Functionality of Silk Fabrics Dyed with Jeju scoria)

  • 임은숙;이혜선;한충훈
    • 한국염색가공학회지
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    • 제23권3호
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    • pp.187-194
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    • 2011
  • This study used Jeju scoria to dye cotton fabric and measured its dyeability, colorfastness, antibacterial activity, deodorization efficiency, ultraviolet protection, and far-infrared emission. The cotton fabric was colored to yellowish red and optimal dyeing can be achieved at a temperature of $80^{\circ}C$ for a dyeing time of 120 minutes with a colorant concentration of 25%(o.w.b). The colorfastness to light, rubbing, perspiration, and washing was 8, 5, 5, and 4~5 ratings respectively, where the wash colorfastness remained after 15 wash cycles. The cotton fabric dyed with Jeju scoria demonstrated excellent antimicrobial activity to Staphylococcus aureus and high deodorization efficiency. Ultraviolet protection factor was as high as 50+. The Jeju scoria can be used as a new colorant for the natural dyeing of silk.