• 제목/요약/키워드: Ulleung Island

검색결과 220건 처리시간 0.032초

해수색 원격탐사에 의한 동해 연근해역 클로로필 a 이상분포 연구 (Study on Abnormal Distribution of High Concentration Chlorophyll a in the East Sea of Korea in Spring Season using Ocean Color Satellite Remote Sensing)

  • 서영상
    • 한국환경과학회지
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    • 제15권1호
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    • pp.59-66
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    • 2006
  • High concentration of chlorophyll a occurred around the Ulleung Warm Eddy off Ulleung Island in the East Sea of Korea in spring season. The abnormal distributions of chlorophyll a were captured by satellite remote sensing and measured field data. The temporal and spatial scale of the abnormal distributions were around 20days and 50km diameter off Ullung Island. The anomalies were quantified b)'estimated chlorophyll a derived from OCM and SeaWiFS ocean color data from 2000 to 2004. The origin of abnormal hish concentrations was estimated by this study. It was that suspended material discharged from the Nakdong River and the coastal water located in the southeastern part of Korean Peninsula moved to northeastern coast, and then moved to off Ullung island, The high chlorophyll a concentrations including inorganic materials were accumulated by anticyclonic eddy such as the Ullung Warm Eddy around Ullung island in the East Sea of Korea in spring season.

울릉도 수계의 부착규조군집의 계절적 변이와 DAIpo에 의한 수질평가 (Seasonal Variation of Epilithic Diatom Community and an Assessment of Water Quality by DAlpo in the Water System of Ulleung Island)

  • 최재신;박정원;이경락;양명숙;김한순
    • 생태와환경
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    • 제37권4호통권109호
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    • pp.378-384
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    • 2004
  • 울릉도 수계의 부착규조군집의 계절적 변이와 DAIpo에 의한 수질평가를 조사하였다. 채집은 2003년 4월, 5월, 7월, 8월, 10월과 11월 그리고 2004년 1월과 2월에 4개의 정점에서 채집하였다. 총 95분류군이 동정되었으며 우점종들은 Nitzschia inconspicua, Achnanthes minutissima, Gomphonema angustum과 Cocconeis placentula var. lineata였다. DAIpo는 51.15에서 77.77의 범위였고 울릉도 수계의 수질은 ${\alpha}$-빈부수성에서 ${\beta}$-빈부수성이었다.

울릉도 추산용출소의 용출 특성 (Discharge Characteristics of the Chusan Spring, Ulleung Island)

  • 조병욱;이병대
    • 한국지하수토양환경학회지:지하수토양환경
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    • 제23권6호
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    • pp.37-45
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    • 2018
  • The source of Chusan Spring water in the Ulleungdo is the precipitation in the Nari caldera basin, which permeates in the Trachitic pumice and tuff area and moves downward, outflowing at the lithologic boundary between the trachyte and Nari tuff. It is known that the discharge rate of the Chusan Spring is large enough to be used for the small hydroelectric power generation, but the exact discharge rate and hydrogeologic characteristics have not been known. The discharge rates of the Spring were measured 11 times, which ranged from $15,220m^3/d$ to $36,278m^3/d$. The discharge rates, measured by the automatic level recorder, for two-year period, were $20,000{\sim}38,000m^3/d$. The variation of discharge rates did not coincide with rainfall event, but showed daily increases of $3,000{\sim}5,000m^3/d$. The annual discharge rate excluding the evapotranspiration and the surrounding stream discharge corresponded to 70.6% of the annual precipitation of the recharge area. Therefore, meteorological observations at the Nari basin, rather than the Ulleung-do meteorological station, are more appropriate to properly interpret the discharge characteristics of the Chusam Spring and the recharge rate of the basin.

New species in two genera, Psammocinia and Ircinia (Demospongiae: Dictyoceratida: Irciniidae), from Korea

  • Sim, Chung Ja;Lee, Kyung Jin;Kim, Young A
    • Journal of Species Research
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    • 제6권spc호
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    • pp.94-109
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    • 2017
  • Eleven new species of two genera, Psammocinia and Ircinia (Demospongiae: Dictyoceratida: Irciniidae) are described from Gageo Island, Ulleung Island and Jeju Island, South Korea. The separation of these two genera was made on basis of morphological evidence, especially skeletal structure with foreign debris. Six new species of Psammocinia and five new species of Ircinia were added to known fauna. All skeletal fibres are very irregular.

전력품질 개선을 위한 HTS SMES 적용 시뮬레이션 (HTS SMES Application Simulation for Power Quality Simulation)

  • 김아롱;김경훈;김진근;박민원;유인근;이상진;박정도;이동영
    • 전기학회논문지
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    • 제59권12호
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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.

Use of big data for estimation of impacts of meteorological variables on environmental radiation dose on Ulleung Island, Republic of Korea

  • Joo, Han Young;Kim, Jae Wook;Jeong, So Yun;Kim, Young Seo;Moon, Joo Hyun
    • Nuclear Engineering and Technology
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    • 제53권12호
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    • pp.4189-4200
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    • 2021
  • In this study, the relationship between the environmental radiation dose rate and meteorological variables was investigated with multiple regression analysis and big data of those variables. The environmental radiation dose rate and 36 different meteorological variables were measured on Ulleung Island, Republic of Korea, from 2011 to 2015. Not all meteorological variables were used in the regression analysis because the different meteorological variables significantly affect the environmental radiation dose rate during different periods, and the degree of influence changes with time. By applying the Pearson correlation analysis and stepwise selection methods to the big dataset, the major meteorological variables influencing the environmental radiation dose rate were identified, which were then used as the independent variables for the regression model. Subsequently, multiple regression models for the monthly datasets and dataset of the entire period were developed.

국내 자생 백리향의 추출용매에 따른 페놀함량 (Phenol Contents of Solvent Extraction in Several Domestic Thymus Quinquecostatus Celak)

  • 백정애;백이화;장매희
    • 생물환경조절학회지
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    • 제18권4호
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    • pp.468-474
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    • 2009
  • 지역별 백리향 지상부 잎의 phenols 성분의 효과적인 추출을 알아보기 위해 추출용매를 달리하여 추출하고, GC-MS로 분석한 결과thymol과 carvacrol을 포함한 phenol함량이 methanol 추출 시 울릉도, 제주 중간산지, 경기도, 제주도 고산지, 강원도 종이 각각 92.21, 84.92, 77.43, 74.16, 73.51%로 추출되었으며, ethanol 추출 시 전체 추출 성분 중 강원도, 제주도 중간산종, 경기도, 울릉도, 제주고산종이 각각 93.64, 93.62, 90.74, 89.52, 72.65% 순으로 나타났다. Hexane을 용매로 추출하였을 때에는 강원도와 울릉도 서식의 백리향은 거의 100, 95.71%의 phenol만 추출되었다.