• Journal of Life Science
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• v.8 no.3
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• pp.333-338
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• 1998

Productivity of alkaline proteinase from Yarrowia lipolytica 504D was investigated. For the production fo the enzyme, hemoglobin was the best nitogen source, however, casein and skim milk were also good. All carbon sources inhibited strongly the producitivity of the enzyme. Yeast extract increased the productivity of the enzyme to 220%, but almost mineral salts except monovalant ions decreased it. Based on these results, optimal medium was composed of 1.2% casein, 0.2% glucose, 0.16% yeast extract, and 0.1% ammonium sulfate. the best condition for the production of the enzyme was observed at pH 9 and $20^{\circ}C$ for 42 hours.

• Environmental Sciences Bulletin of The Korean Environmental Sciences Society
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• v.3 no.3
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• pp.189-196
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• 1999

The community structure, phytomass, and primary productivity in Thuja orientalis stands on a limestone area located in Maepo-up, Chungbuk province in Korea were estimated quantitatively. Seven species including a small proportion of Quercus dentata were identified in the tree layer, 26 species including Ulmus macrocarpa in the shrub layer, and 79 species including Carex lnceolata in the herb layer of the Thuja stands. The vertical distribution of the fine root phytomass exhibited a power functional decrease relative to the soil depth. The seasonal changes in the fine root phytomass at a soil depth of 5 cm were closely related to the pecipitation in the study area. The productivity of the stand of stems, branches, leaves, and roots were 10.72, 0.82, 0.45 and 6.46 ton DM. $ha^{-1}$ .$yr^{-1}$, respectively. The Thuja stand had a high foliage(25%) and low rate of production per unit of foliage. The annual turnover rate of the fine roots int he Thuja stand was 6.71 $yr^{-1}$. The net primary production of the overstory including the understory was estimated at 19.48 ton DM.$ha^{-1}$.$yr^{-1}$ including an underground section of 6.46 ton DM.$ha^{-1}$.$yr^{-1}$(33%). The allocation ratio of net production to root was lower in the limestone Thuja communities than at the nearby non-limestone ones, whereas the production efficiency to leaf weight was higher in the limestone communities. These results would seem to indicate that the limited production capacity is due to the calcium toxicity and low availability of iron and phosphorus in a limestone soil with a high pH, calcium, and bicarbonate content with a strategy for survival in a hostile habitat.

• Journal of Technology Innovation
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• v.25 no.3
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• pp.83-113
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• 2017

This paper constructs panel data of inventors listed on patents applied for the KIPO during 1991-2005 and analyzes the effects of network characteristics on inventor productivity. The findings are as follows: ⅰ) Strong ties within a network have positive effects on inventor productivity. ⅱ) An inventor with high centrality shows high producitivity. ⅲ) Technological diversity of a network enhances inventor productivity. ⅳ) An inventor belonging to a network of good quality shows higher productivity. ⅴ) Network size is positively related with inventor producitvity. ⅵ) A lone inventor shows the highest productivity among types of inventors, and a co-inventor with the experience of standalone invention is more productive compared to an inventor with only the experience of co-invention. ⅶ) The productivity effects of network variables differ across regions. ⅷ) Differences among regions do not decrease though geographical boundaries become less important.

• The Journal of the Korea Contents Association
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• v.15 no.3
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• pp.388-395
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• 2015

The purpose of this study is to estimate change of productivity of information and technology industry and to induce policy implications. The method of analysis is panel data analysis based on 11 Korean information and technology industry cross-section and 8 years time series. The result of estimate shows that producitivity of labor and capital and information and technology industry is positive, total factor productivity of information and technology industry is also positive. but total factor productivity decreased after 2008. In addition, the productivity of labor was increased, but the productivity of capital input was decreased. It means that the productivity of Korean information and technology industry was not improved despite increasing of labor and capital investment.