• Title/Summary/Keyword: 종조성

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Ecological Stability of the Shihwa Lake Evaluated by Zooplankton Distribution in the Lake Shihwa and Adjacent Coastal Area (시화호와 인근 해역의 동물플랑크톤 분포로 본 시화호의 생태적 안정성)

  • Park, Chul;Huh, Sung-Hoi
    • The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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    • v.2 no.2
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    • pp.87-91
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    • 1997
  • Ecological stability of the Lake Shihwa, artificially made by the construction of the Shihwa Dike, was evaluated by the species composition and variation in biomass of zooplankton. Species composition and seasonal variation in biomass in the seaside stations were similar to those observed in nearby bays and coastal zone. However, those in the lake sites showed very different patterns. The brackish water copepod, Sinocaianus tenellus, held the first rank in every season (with more than 66% in spring, 98% in summer and fall, and 80% in winter). The species composition was very simple and the biomass (in terms of total individuals $m^{-3}$) varied markedly with season up to the order of $10^4$ magnitude. These results imply that the lake ecosystem made by the construction of Sihwa dike is in very unstable stage probably due to the input of industrial wastes as well as unpredictable variation in salt content caused by irregular control of the watergate of the dike and resultant irregular flow direction of the water through the gate.

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Restoration Effects Confirmed in the Environmental Forests Created on the Bases of Ecological Principles (생태학적 원리를 적용하여 창조된 환경림에서 확인된 복원 효과)

  • 이창석;이안나
    • Korean Journal of Environmental Biology
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    • v.22 no.1
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    • pp.220-226
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    • 2004
  • The restoration effects in two sorts of forests created and managed on the bases of ecological principles in Sihwa industrial complex and Mt. Surak respectively were evaluated in both viewpoints of species composition and diversity. Species composition of the forests created based on the ecological design was move similar to that of the natural forests compared wit h the forests constructed by applying the landscape architectural method. The increased species diversity in the ecologically created forest reflected the effect as well. Black locust plantation managed by applying the ecological principle showed move similar species composition to the surrounding natural forest than the forest left without any management. Furthermore, the former forest showed higher species diversity than the latter one. The methods, which create and manage a forest based on ecological principles, revealed several problems, such as lack of specialty of project operators and inspecting officers, construction regulations without the ecological background, absence of the endemic young trees to be introduced in diverse natural environment, etc. Preparation of guidance for ecological planting and systematic environmental education including revision of construction regulation were recommended as the measures to solve such problems.

Theoretical Calibration of the Composition of Multicomponent Thin Film Obtained by Wavelength Dispersive Spectroscopy (WDS로 측정한 다성분계 박막 조성의 이론적인 보정)

  • Byeon, Gyeong-Mun;Lee, Won-Jong
    • Korean Journal of Materials Research
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    • v.7 no.7
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    • pp.597-603
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    • 1997
  • 파장분산 분광분석기(Wavelength Dispersive Spectroscopy, WDS)는 다른 분석 방법에 비해 분해능이 좋고 측정 시간이 적게 걸리며, 또한 비용면에서 경제적이고 정량값이 실제값과 다르게 측정될 수 있다. 즉, 다성분계 박막에 있엇 X-선 발생 깊이가 작은 원소의 경우 X-선 발생 깊이가 큰 원소에 비해 조성값이 과장되어 측정된다. PZT박막의 경우에도 WDS로 측정한 조성은 박막의 두께에 따른 정확한 보정이 필요하다. 본 연구에서는 WDS를 이용하여 PZT박막의 조성을 측정할 때, 얇은 박막의 경우에도 조성을 정확하게 알아낼 수 있도록 박막의 두께에 따른 조성의 보정법을 제시하였다. 또한, 박막의 두께를 직접 측정하는 과정없이 WDS분석 결과로 얻는 각 원소들의 [ZAF]k 의 합으로부터 박막의 두께를 이론적으로 구하였으며, 이를 실험값과 비교하였다.

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Seasonal Fluctuations and Species Composition of Fish Collected by Long-bag Stow Net in Nang-island, Yeosu (여수 낭도 연안에서 낭장망에 어획된 어류의 종조성 및 계절변동)

  • Yu, Tae-Sik;Youn, Byoung-Il;Kim, Joon;Han, Kyeong-Ho
    • Korean Journal of Ichthyology
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    • v.32 no.2
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    • pp.91-96
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    • 2020
  • Seasonal fluctuation in abundance and species composition of fish in coastal waters off Nang island were investigated using seasonal samples collected by long-bag stow net in 2017. A total 10,208 fish were sampled and classified into 37 species, 26 families, and 9 orders. The dominant species were Engraulis japonicus (4,886 individuals, 47.9%), Pennahia argentata (842 individuals, 8.2%), and Ilisha elongata (369 individuals, 3.6%). The diversity index was the highest in May (H'=3.23) and the lowest in November (H'=1.24). The dominance index was the highest in November (D=78.7%) and the lowest in May (D=22.4%).

Species Composition of Fishes in Eelgrass Bed of Geoje Bay on Geoje Island, Korea (거제도 거제만 잘피밭의 어류 종조성)

  • Lee, Dae-Hee;Kim, Tae-Jin;Choi, Byung-Eon;Lee, So-Jeong;Gwak, Woo-Seok
    • Korean Journal of Ichthyology
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    • v.22 no.3
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    • pp.179-185
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    • 2010
  • This is a study of the fish assemblages in eelgrass beds of Geoje Bay on Geoje Island, Korea. Samples were collected by surf net monthly from June 2006 to May 2007. A total 26 species, 1,825 individuals, and 4,483.1 g of fishes were collected. The dominant species were Acentrogobius pflaumii, Aulichthys japonicus, Gymnogobius heptacanthus, Rudarius ercodes, Chaenogobius annularis, Gymnogobius urotaenia, Syngnathus schlegeli, Pterogobius elapoides, Zoarchias glaber, Takifugu niphobles, Zoarchia suchidai. These species accounted for 90.6% of the total number of individuals and 76.2% of the biomass of the fishes collected. The fish assemblages in the eelgrass beds showed clear seasonal changes; the number of fish species and individuals increased in March and were highest in September, whereas the biomass attained its highest level in May and subsequently decreased. Meanwhile the species diversity indices showed their highest value in December.