• 제목/요약/키워드: growth dynamics

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Growth dynamics of the seagrass, Zostera marina in Jindong Bay on the southern coast of Korea

  • Kim, Young-Kyun;Kim, Jong-Hyeob;Kim, Seung-Hyeon;Kim, Jae-Woo;Park, Sang-Rul;Lee, Kun-Seop
    • ALGAE
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    • 제27권3호
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    • pp.215-224
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    • 2012
  • Growth dynamics of the seagrass, Zostera marina were examined at the two stations (Myungju and Dagu) in Jindong Bay on the southern coast of Korea. Eelgrass leaf productivities, underwater irradiance, water temperature, dissolved inorganic nitrogen (DIN) in water column and sediments, and tissue carbon (C) and nitrogen (N) content were monitored monthly from March 2002 to January 2004. Underwater irradiance fluctuated highly without a clear seasonal trend, whereas water temperature showed a distinct seasonal trend at both study stations. Water column DIN concentrations were usually less than $5{\mu}M$ at both study sites. Sediment pore water $NH_4{^+}$ and $NO_3{^-}+NO_2{^-}$ concentrations were higher at the Myungju site than at the Dagu site. Eelgrass leaf productivity at both study sites exhibited a distinct seasonality, increasing during spring and decreasing during summer. Seasonal variation of eelgrass productivity was not consistent with seasonal patterns of underwater irradiance, or water temperature. Eelgrass tissue C and N content at both study sites also showed significant seasonal variations. Relationships between tissue C and N content and leaf productivities exhibited usually negative correlations at both study sites. These negative correlations implied that the growth of Z. marina at the study sites was probably limited by C and N supplies during the high growth periods.

밀폐된 구획실의 체적변화가 최대 열발생률에 미치는 영향에 관한 수치해석 연구 (A Numerical Study on the Effect of Volume Change in a Closed Compartment on Maximum Heat Release Rate)

  • 윤홍석;남동군;황철홍
    • 한국화재소방학회논문지
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    • 제31권5호
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    • pp.19-27
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    • 2017
  • 밀폐된 구획실 화재에서 화원의 면적 및 위치, 화재성장률, 구획 체적의 변화가 열발생률을 포함한 주요 화재특성에 미치는 영향이 검토되었다. 이를 위해 닫힌 개구부가 적용된 ISO 9705 화재실을 대상으로 Fire Dynamics Simulator (FDS)를 활용한 화재시뮬레이션이 수행되었다. 주요 결론으로서, 화원의 면적 및 위치의 변화는 최대 열발생률, 총 열량, 상층부의 최대 온도 및 화학종 농도를 포함한 구획 내의 열적 특성과 화학적 특성에 큰 영향을 주지 않음을 확인하였다. 그러나 화재성장률과 구획 체적의 증가는 최대 열발생률 및 총 열량의 증가를 가져오며, 한계산소농도의 감소 및 최대 CO 농도의 증가를 발생시킨다. 마지막으로 화재성장률과 구획 체적의 함수로 표현된 최대 열발생률의 상관식을 도출하여, 밀폐된 구획실 화재에 대한 화재성장곡선의 적용을 위한 방법론이 제안되었다.

황칠나무의 집단구조와 치수의 발생과 생육동태 및 공간분포 (Population Structure, and Emergence and Growth Dynamics of Seedling, and Spatial Distribution of Dendropanax morbifera Lev.(Araliaceae))

  • 정재민
    • 한국자원식물학회지
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    • 제11권3호
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    • pp.345-352
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    • 1998
  • A Korean endemic and evergreen small tree ' Dendropanax morbifera $L_{EV}$.(Araliaceae)' is a component of evergreen forest and mainly idstributein sourthern region and islands in Korea. A local population of D. morbifera which is located between evergreen and deciduous forest within 50m x 50m quadrate was investigated to ascertain the change of population structure, emergence and growth dynamics of seedlings and saplings, and pattern of spatial distribution by the temproal and spatial expansion of population . The result of analysis of population structure by Importnace Value(IV), evergreen forest showed a high species diversity of evergreen tree species such as Cinnamomum japonicum, Machilus japonica, Neolitsea serica, Daphniphyllum macropodum, Ligustrum japonicum, and etc, in middle and under story than in upper story where Camelia japonica and Quercus acuta were dominant. And in conterminous deciduous fores, the major component of evergreen forest in this region, Camellia japonica, Quercus acuta, evergreen tree of Lauraceae and etc. were abundant in only under story. IV of D. morbifera differed from among three story. In comparative analysis of emergence and growth dynamics of D. morbifera seedlings and saplings between evergreen and deciduous forest, emergece and density of seedlings were significantly greater in evergreen than in deciduous forest, and growth of height and basal diameter of seedlings and saplings were slightly larger in evergreen than in deciduous forest. The spatial distribution patterns by Moristia's index mapping of indivuduals using a lattice method of XY axis within this population showed that seedlings(age up to 2 years) and saplings (age>2 years and height<1m) both evergreen and deciduous forest were more or less aggregated apart from mature trees, and thougth intermediate trees(height>1m and dbh<10cm) had a aggregated distribution pattern, mature trees(dbh>10cm were uniform. In conclusion , the expansion of D. morbfera population from evergreen to deciduous forest accompanied with a mumber of evergreen woody species, and also, emergence and recruitment, and growth of seedlings were greatly influenced moisture and canopy by around community structure.

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The Influence of Human Capital on GDP Dynamics: Modeling in the COVID-19 Conditions

  • Derii, Zhanna;Zosymenko, Tetiana;Shaposhnykov, Kostiantyn;Tochylina, Yuliia;Krylov, Denys;Papaika, Oleksandr
    • International Journal of Computer Science & Network Security
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    • 제22권3호
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    • pp.67-76
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    • 2022
  • COVID-19 struck labor markets around the world, exposing and exacerbating the gender inequalities within the human capital structure. The last, in its turn, jeopardizes the return of the national economies to the growth trajectory undermined by pandemic impact. The authors assume that COVID-19 disproportionately affected the employment rates of women and men, which led to increased gender inequality in the labor market, which, in turn, affected GDP growth rates in the EU. To prove this hypothesis two research questions are discovered: 1) whether there was a different correlation between the number of COVID-19 cases in the EU and indicators of the labor market for women and men; and 2) whether there was a link between the growth of gender inequality in the EU labor market and the GDP dynamics in these countries. The analysis of the correlation between the number of cases of COVID-19 and indicators of the labor market in the EU revealed faster growth of women's unemployment rates compared to men's ones as the COVID-19 incidence unfolded. Multiple linear regression and factor analysis have been used to investigate the influence of gender inequality in the labor market on GDP dynamics. Despite the methodological limitations, the proposed model is both a sound argument and an analytical basis in favor of gender-responsive economic recovery backed by the systematic and consistent gender equality policy of a government.

한국 서해남부 해역에 분포하는 넓적뿔꼬마새우(Latreutes planirostris)의 생식생태 및 개체군 동태 (Reproductive Biology and Population Dynamics of Latreutes planirostris in the South-Western Waters of Korea)

  • 오철웅;나종헌;마채우
    • 한국수산과학회지
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    • 제36권2호
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    • pp.144-150
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    • 2003
  • Reproductive biology and population dynamics of Latreutes planirostris were investigated on the south western waters of Korea from June 2001 to May 2002. This paper describes sex ratio, population growth, and reproductive aspects of Latreutes planirostris. Brood size was an isometric function of female carapace length. Based on dry weight, reproduction effort (mass of eggs/mass of female) averaged 0.23. Ovarian examination showed that there was significantly higher gonadosomatic index from May to September, with a peak in June. Statistical analysis revealed that the ovarian dry weight of females with eyed eggs was significantly higher than that of those with non-eyed eggs. This suggests that females were potentially consecutive breeders. Sex ratio showed that female is more numerous than male. Growth parameters mortality and recruitment were estimated by monthly length-frequency data. Growth parameters were estimated, using the seasonalized von Bertalanffy growth function model $(L\infty\;=\;12.70\;mm\;CL,\;K\;=\;0.87yr^{-1},\;C\;=\;0.96,\;WP\;=\;0.59)$. The recruitment pattern was twice a year.

Macroscopic and microscopic mass transfer in silicon czochralski method

  • Kakimoto, Koichi
    • 한국결정성장학회지
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    • 제9권4호
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    • pp.381-383
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    • 1999
  • First topic of this paper aims to clarify how oxygen and heat transfer in silicon melt under cusp-shaped magnetic fields. We obtained asymmetric temperature distribution by using time dependent and three-dimensional calculation. Second topic is study on molecular dynamics simulation, which was carried out to estimate diffusion constants of oxygen in silicon melt.

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기업가의 창업위치선택과 클러스터의 성장동력: 바이오벤처의 창업을 중심으로 (Location Decisions of Startups and Dynamics of Cluster Growth)

  • 손동원
    • 기술혁신연구
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    • 제17권1호
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    • pp.69-95
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    • 2009
  • 본 논문은 벤처기업가의 창업위치결정에 대한 분석을 통해 기업집적의 전략적도구로 인정되는 클러스터의 성장 동력을 체계적으로 분석했다. 한 기업가의 창업위치 결정은 '전략적 사안'으로서, 다음의 세 가지 동력의 상호작용에 의해 작동함을 도출하였다. 그 세가지 동력은 창업위치에 본질적으로 담겨진 효용과 비용의 편차, 신규 진입기업의 연구개발 역량, 클러스터에 이미 진입해 있는 기존기업의 연구개발 역량 등이다. 본 논문은 신생기업의 입장이 클러스터에 진입하는 것에 존재하는 긍정적인 면과 부정적인 면을 제안하면서 연구가설을 도출하였다. 그 긍정적인 면은 기존기업의 지식 스필오버에 의한 지식학습 효과이며, 부정적인 면은 지식뺏김 효과이다. 이 양 측면에 대한 전략적 결정에 의해 창업위치가 결정되고, 거시적으로는 클러스터의 성장 여부가 결정됨을 가설로 설정했다. 한국 바이오 벤처기업 710개를 실증대상으로 선정해서, 앞서 설정한 논리에서 도출된 연구가설들을 검증하였다. 실증분석에서 발견은, 조직유산과 클러스터의 경쟁상황에 의해 비용과 효과가 달라진다는 점, 그리고 클러스터에서 작동하는 협력규범의 존재 등에 의해 신생기업이 클러스터에서 창업하게 됨을 발견하였다. 결론적으로 신생기업에게 전달되는 지식 스필오버 효과가 클 때 기업집적 효과가 증가하며, 클러스터가 성장하게 됨을 확인하였다.

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