• Title/Summary/Keyword: Min Geung Ho

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Diel Pattern of Littoral Swarming in Moina macrocopa and Impact of Juvenile Fish Density

  • Jeong, Hyun-Gi;La, Geung-Hwan;Kim, Hyun-Woo;Jang, Min-Ho;Jeong, Kwang-Seuk;Yoon, Ju-Duk;Joo, Gea-Jae
    • Korean Journal of Ecology and Environment
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    • v.43 no.4
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    • pp.513-517
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    • 2010
  • The diel swarming of Moina macrocopa and the relationship between environmental factors were evaluated in a shallow reservoir. The littoral density of Moina macrocopa maintained low from night to noon, reached maximum density at the afternoon with compact swarms at the waters' edge, and dispersed after sunset. The recruitment of Moina macrocopa and changes of water temperature (r=0.709, p<0.001) and juvenile fish density (r=0.511, p=0.002) in the littoral zone showed a significant positive relationships. After the induction of diel horizontal migration toward littoral zone, therefore, direct juvenile fish predation pressure should be induced Moina macrocopa swarming.

CONSTRUCTION, ASSEMBLY AND COMMISSIONING OF KSTAR MAIN STRUCTURES

  • Yang, Hyung-Lyeol;Bak, Joo-Shik;Kim, Byung-Chul;Choi, Chang-Ho;Kim, Woong-Chae;Her, Nam-Il;Hong, Kwon-Hee;Kim, Geung-Hong;Kim, Hak-Kun;Sa, Jeong-Woo;Kim, Hong-Tack;Kim, Kyung-Min;Kim, Sang-Tae
    • Nuclear Engineering and Technology
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    • v.40 no.6
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    • pp.439-450
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    • 2008
  • The KSTAR device succeeded in first plasma generation on $13^{th}$ June of 2008 through comprehensive system test and commissioning. Among various kinds of the key factors that decisively affected the project, success in the construction and assembly of the major tokamak structure was most important one. Every engineering aspects of each structure were finally confirmed in the integrated commissioning period, and there were no severe troubles and failures prevented the KSTAR device from operating during the commissioning and the first plasma experiments. As a result, all of the experiences and technologies achieved through the KSTAR construction process are expected to be important fundamentals for future construction projects of superconducting fusion devices. This paper summarizes key engineering features of the major structures and of the machine assembly.

The Reconstruction of Life Story of Koryo-saram Min Tatyana (고려인 민 타찌아나의 생애 이야기 재구성)

  • Yun, Heejin;Kim, Youngsoon;Aigozhayeva, Aigerim;Bekboeva, Aigul
    • Asia-pacific Journal of Multimedia Services Convergent with Art, Humanities, and Sociology
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    • v.6 no.10
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    • pp.449-456
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    • 2016
  • In this study we recomposed the life story of Min Tatyana who is a Koryo-saram, or in other words, an ethnic Korean residing Kazakhstan. The life story of an overseas Korean, or Koryo-saram to be exact, includes in itself their multi-level identity which consists of the period of the immigration of Koryo-sarams, the special incident of deportation, as well as life as people of the Soviet Union and Kazakhstan, and life as a Korean race. In this study, we were confirmed the texture of the Korean race thought ordinary korean Min Tatyana life who living in Kazakhstan. The life story of Min Tatyana was reconstituted into two stories as "growing up in a multicultural society as Koryo-Saram" and "to live a life as the descendants of independence activist". She was born in historically region Kyzylorda, where living Korean groups and now she is living in Almaty, where living the many koreans ethnic groups of Kazakhstan. Also, her parents were respected to the local residents and her grandfather of husband was famous independent activist. These aspects have helped keep her Korean ethnic identity. The life story of Min Tatyana is personal story and qualitative text, which shows social, cultural background of korean ethnic who living in Kazakhstan. This study is expected to help to confirm the Koryo-Saram characteristics and aspect of their multilayer life.

Initial Preliminary Studies in National Long-Term Ecological Research (LTER) Stations of Daechung Reservoir

  • Lee, Sang-Jae;Lee, Jae-Hoon;Kim, Jong-Im;La, Geung-Hwan;Yoem, Min-Ae;Shin, Woong-Ghi;Kim, Hyun-Woo;Jang, Min-Ho;An, Kwang-Guk
    • Korean Journal of Ecology and Environment
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    • v.42 no.4
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    • pp.476-486
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    • 2009
  • Major objective of our study was to introduce initial researches of national long-term ecological monitoring studies on Daechung Reservoir, as one of the representative lentic reservoir ecosystems in Korea. For the long-term ecological research (LTER), we conducted preliminary field monitoring during 2008~2009 and analyzed biological parameters such as phytoplankton, zooplankton, and freshwater fish along with chemical water quality and empirical model analysis. According to phytoplankton surveys, major taxa have varied largely depending on seasons and sites sampled. Overall phytoplankton data showed that cyanophyta dominated in the summer period and diatoms dominated in the winter. In zooplankton analysis, 25 species including 20 rotifers, 3 cladocerans and 2 copepods were collected during the survey. The relative abundance of rotifers (86.5%) was always greater than that of cladocerans (6.3%) or copepods (5.1%). There were distinct spatial and inter-annual changes in the abundance of zooplankton in the reservoir, displaying similar patterns in three sites with the exception of S3 during the study. According to fish surveys, 8 families and 39 species were observed during 2008~2009. The most dominant fish was an exotic species of Lepomis macrochirus (23%), indicating an severe influence of exotic species to the ecosystem. TP averaged $17.9\;{\mu}g\;L^{-1}$ ($6{\sim}80\;{\mu}g\;L^{-1}$), which was judged as a mesotrophy, and showed a distinct longitudinal gradients. TN averaged $1.585\;{\mu}g\;L^{-1}$ during the study and judged as hypereutrophic condition. Unlike TP, TN didn't show any large seasonal and spatial variations. Under the circumstances, nitrogen limitation may not happen in this system, indicating that nitrogen control is not effective in the watershed managements. These data generated in the LTER station will provide key information on long-term biological and water quality changes in relation to global warming and some clues for efficient reservoir ecosystem managements.

Changes of Growth and Quality of Creeping Bentgrass by Greywater Irrigation (중수돗물 관수에 따른 크리핑벤트그래스의 생육과 품질)

  • Lee, Jong-Jin;Kim, Young-Sun;Lee, Jae-Pil;Yoon, Min-Ho;Lee, Geung-Joo
    • Weed & Turfgrass Science
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    • v.4 no.4
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    • pp.390-396
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    • 2015
  • Water shortage is becoming a serious problem of turfgrass management on sand green. Many superintendents in golf course in Korea have interested in use of irrigation of recycled water for turfgrass water management. This study was conducted to investigate the effect of greywater as an irrigation source on the growth and quality of creeping bentgrass green. Turfgrass was irrigated with tap water (TW) and greywater (GW), under with or without compound fertilizer application (nonfertilizer + TW, N-TW; non-fertilizer + GW, N-GW; fertilizer + TW, F-TW; fertilizer + GW, F-GW). The chemical properties of the green sand soil were not changed by irrigation. Turf color index, chlorophyll index, root length, clipping yield and nutrient uptake of GW treatment were similar to TW treatment. The growth and quality of turfgrass were more likely related with the fertilizer application than irrigation source or quality. These results indicated that GW could be used as alternative irrigation source on the sand greens of golf courses.

Analysis of Food Web Structure of Nakdong River Using Quantitative Food Web Parameters Obtained from Carbon and Nitrogen Stable Isotope Ratios (낙동강 수생태계 먹이망 구조 분석: 안정동위원소 비 기반의 정량적 생태정보를 이용한 영양단계 시공간 분포 경향 파악)

  • Oh, Hye-Ji;Jin, Mei-Yan;Choi, Bohyung;Shin, Kyung-Hoon;La, Geung-Hwan;Kim, Hyun-Woo;Jang, Min-Ho;Lee, Kyung-Lak;Chang, Kwang-Hyeon
    • Korean Journal of Ecology and Environment
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    • v.52 no.1
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    • pp.50-64
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    • 2019
  • Recently, quantitative analyses of food web structure based on carbon and nitrogen stable isotopes are widely applied to environmental assessments as well as ecological researches of various ecosystems, particularly rivers and streams. In the present study, we analyzed carbon and nitrogen stable isotope ratios of POM (both planktonic and attached forms), zooplankton, benthic macroinvertebrates and fish collected from 6 sites located at Nakdong River. Samples were collected from upstream areas of 5 weirs (Sangju, Gangjeong-Goryeong, Dalseong, Hapcheon-Changnyeong, and Changnyeong-Haman Weirs) and one downstream area of Hapcheon-Changnyeong Weir in dry season (June) and after rainy season (September). We suggested ranges of their carbon and nitrogen stable isotope ratios and calculated their trophic levels in the food web to compare their temporal and spatial variations. Trophic levels of organisms were relatively higher in Sangju Weir located at upper part of Nakdong River, and decreased thereafter. However, the trophic levels were recovered at the Changnyeong-Haman Weir, the lowest weir in the river. The trophic level calculated by nitrogen stable isotope ratios showed more reliable ranges when they were calculated based on zooplankton than POM used as baseline. The suggested quantitative ecological information of the majority of biological communities in Nakdong River would be helpful to understand the response of river food web to environmental disturbances and can be applied to various further researches regarding the quantitative approaches for the understanding food web structure and function of river ecosystems as well as restoration.