• Title/Summary/Keyword: 산성도

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Determinants of Productivity in Korean Logistics Industry - Focusing on Market Power and Firm Structure - (한국 물류산업의 생산성 결정요인 - 시장지배력과 기업구조를 중심으로 -)

  • Kim, Jong-Ho
    • International Area Studies Review
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    • v.13 no.1
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    • pp.123-143
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    • 2009

  • This paper investigates the determinants of total factor productivity(TFP) growth in Korean logistics industry such as market share, ownership structure, age of firm, firm size and debt ratio. Using financial data on individual firms in Korean logistics industry, we first estimate firm-level TFP growth rate and then, regress the estimated TFP growth rate on individual firms market power and structural characteristics. Our empirical results show that logistics firms market share is negatively correlated with their TFP growth rate. Also, we find that older or larger firms are more likely to have higher TFP growth rate.

Genesis of the acidic metavolcanic rocks distributed around the Chungju iron deposit in the Gyemyeongsan Formation (계명산층 내의 충주 철광상 주변에 분포하는 산성 변성화산암의 성인)

  • Park Maeng-Eon;Kim Gun-Soo;Park Kye-Hun
    • The Journal of the Petrological Society of Korea
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    • v.14 no.3 s.41
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    • pp.169-179
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    • 2005

  • Acidic metavolcanic rocks distributed around the Chungju iron deposit show significantly high abundances of rare earth elements and high field strength elements. Relatively high ${\epsilon}_{Nd}$(0) values and lack of negative Nb anomaly suggest that assimilation of crustal material is not involved in their generation. They are plotted within the within-plate environment according the tectonic discrimination diagrams. Such geochemical characteristics are very similar to the acidic metavolcanic rocks of Munjuri Formation. They also show geochemical characteristics of Al-type magma of Eby (1992). All such diagnostic characters indicate differentiation of mantle-derived magma produced from the rift environment, related to the breakup of continent. In contrast to the alkali granites and the rare metal deposit both having age of c. 330 Ma, Sm-Nd isotopic data of the acidic metavolcanic rocks do not form well defined isochron. However, the alkali granites reveal low ${\epsilon}_{Nd}$(0) values, while the acidic metavolcanic rocks and the rare metal deposit both have significantly higher ${\epsilon}_{Nd}$(0) values. Considering such differences, we propose following generation hypothesis: The acidic metavolcanic rocks around Chungju iron deposit was erupted at 750 Ma as rest of the acidic metavolcanic rocks of Gyemyeongsan and Munjuri Formations. About 330 Ma ago, partial melting of existing Al-type igneous materials and some old crustal materials produced alkali granite. The rare metal deposit was also produced by redistribution of related materials within the acidic volcanics due to hydrothermal activities occurred at the same time. Sm-Nd isotopic systematics of the acidic metavolcanic rocks were disturbed during the regional metamorphic event at ca. 280 Ma.

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