• KOREAN JOURNAL OF CROP SCIENCE
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• 제46권3호
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• pp.241-247
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• 2001

Boundary line method was adopted to analyze the relationships between rice yield and meteorological conditions during rice growing period. Boundary lines of yield responses to mean temperature($T_a$) and sunshine hour( $S_{h}$) and diurnal temperature range($T_r$) were well-fitted to hyperbolic functions of f($T_a$) =$$\beta$_{0t}$(1-EXP(-$$\beta$_{1t}$ $\times$ ($T_a$) ) and f( $S_{h}$)=$$\beta$_{0t}$((1-EXP($$\beta$_{1t}$$\times$ $S_{h}$)), to quadratic function of f($T_r$) =$\beta$$_{0r}$(1-($T_r$ 1r)$^2$), respectively. to take into account to, the sterility caused by low temperature during reproductive stage, cooling degree days [$T_c$ =$\Sigma$(20-$T_a$] for 30 days before heading were calculated. Boundary lines of yield responses to $T_c$ were fitted well to exponential function of f($T_c$) )=$\beta$$_{0c}$exp(-$$\beta$_{1c}$$\times$$T_c$ ). Excluding the constants of $\beta$$_{0s}$ from the boundary line functions, formed are the relative function values in the range of 0 to 1. And these were used as yield indices of the meteorological elements which indicate the degree of influence on rice yield. Assuming that the meteorological elements act multiplicatively and independently from each other, meteorological yield index (MIY) was calculated by the geometric mean of indices for each meteorological elements. MIY in each growth period showed good linear relationship with rice yield. The MIY's during 31 to 45 days after transplanting(DAT) in vegetative stage, during 30 to 16 days before heading (DBH) in reproductive stage and during 20 days after heading (DAH) in ripening stage showed greater explainablity for yield variation in each growth stage. MIY for the whole growth period was calculated by the following three methods of geometric mean of the indices for vegetative stage (MIVG), reproductive stage (HIRG) and ripening stage (HIRS). MI $Y_{I}$ was calculated by the geometric mean of meteorological indices showing the highest determination coefficient n each growth stage of rice. That is, (equation omitted) was calculated by the geometric mean of all the MIY's for all the growth periods devided into 15 to 20 days intervals from transplanting to 40 DAH. MI $Y_{III}$ was calculated by the geometric mean of MIY's for 45 days of vegetative stage (MIV $G_{0-45}$ ), 30 days of reproductive stage (MIR $G_{30-0}$) and 40 days of ripening stage (MIR $S_{0-40}$). MI $Y_{I}$, MI $Y_{II}$ and MI $Y_{III}$ showed good linear relationships with grain yield, the coefficients of determination being 0.651, 0.670 and 0.613, respectively.and 0.613, respectively.

• Journal of the Korean Ceramic Society
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• 제41권6호
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• pp.464-470
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• 2004

The electrical stability of ZPCCY-based varistors composing of ZnO-Pr$_{6}$O$_{11}$-CoO-C $r_2$ $O_3$- $Y_2$ $O_3$ ceramics were investigated in various DC accelerated aging stress with sintering times. Sintering time greatly affected electrical properties and stability. Sintering time decreased nonlinear exponent in the range of 51.2∼23.8 and increased leakage current in the range of 1.3∼5.6 ${\mu}$A. The varistor sintered for 1 h exhibited high nonlinearity, whereas relatively low stability. On the contrary, the varistor sintered for 3 h exhibited low nonlinearity, whereas relatively high stability. But the varistor sintered for 2 h exhibited not only good nonlinearity, with nonlinear exponent of 38.6 and leakage current of 3.6 ${\mu}$A but also high stability, in which the variation rates of varistor voltage, nonlinear exponent, leakage current, and dissipation factor are -0.80%, -1.81 %, +74.4%, and +0.88%, respectively.

• International Commerce and Information Review
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• 제19권2호
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• pp.259-273
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• 2017

This study is a meta-analysis of the articles published over the last 18 years from the first edition of the "International Commerce and Information Review" to December 2016. 1047 papers were published in "International Commerce and Information Review" until 2016. Many articles appeared in the order of electronic trade field, product and service innovation field, regional trade information field, trade law system field, and trade negotiation field. There are more than 15 major fields of authors who have published more than 20 papers."International Commerce and Information Review" is a multi-disciplinary journal by scholars in various major fields. Most of the authors belong to universities and the proportion of papers that receive research grants is 19.7%. 46 authors have published more than 5 papers in "International Commerce and Information Review", and their H-index is 5.6. Influence Index (IF) of the "International Commerce and Information Review" in 2016 is 1.02. The main keywords of the papers published in "International Commerce and Information Review" are e-commerce, Internet, service trade, China, e-trade, Korean Wave, FTA, SME and foreign direct investment.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 한국정밀공학회 2012년도 추계학술대회 논문집
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• pp.153-154
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• 2012

• Proceedings of the Korean Society of Precision Engineering Conference
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• 한국정밀공학회 2013년도 춘계학술대회 논문집
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• pp.325-326
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• 2013

• Proceedings of the Korean Society of Precision Engineering Conference
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• 한국정밀공학회 2010년도 춘계학술대회 논문집
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• pp.579-580
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• 2010

• Proceedings of the Korean Society of Precision Engineering Conference
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• 한국정밀공학회 2010년도 춘계학술대회 논문집
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• pp.183-184
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• 2010

• Proceedings of the Korean Society of Precision Engineering Conference
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• 한국정밀공학회 2009년도 추계학술대회 논문집
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• pp.265-266
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• 2009

• Proceedings of the Korean Society of Precision Engineering Conference
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• 한국정밀공학회 2011년도 춘계학술대회 논문집
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• pp.789-790
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• 2011

• Korean Journal of Ecology and Environment
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• 제54권2호
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• pp.108-119
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• 2021

We aimed to develop a naturalness index for forest-dwelling birds in four national parks in Korea and to simulate the effect of species loss on this naturalness index. Five bird specialists were asked to give 112 bird species a disturbance susceptibility score (DSS), and the naturalness index was calculated based on this. The 112 bird species represented 8 orders (Cuculiformes, Piciformes, Accipitriformes, Falconiformes, Columbiformes, Caprimulgiformes, Strigiformes, and Passeriformes). DSS was the highest for Terpsiphone atrocaudata and Pitta nympha, and lowest for Pica pica, Hypsipetes amaurotis, and Streptopelia orientalis. There was a significant negative relationship between a species' population number and its DSS. Among the four national parks, Mt. Songni had the highest naturalness index, followed by Mt. Wolak, Mt. Juwang, and Mt. Wolchul. We investigated the change in biodiversity indices under four scenarios, which assumed the extinction of species with less than 5 (Scenario 1), 10 (Scenario 2), 50 (Scenario 3), and 100 individuals (Scenario 4). The results showed that although all biodiversity indices decreased as the species loss increased, they all behaved differently. Fisher's alpha diversity decreased as the number of species proportionally decreased. There was almost no change in Shannon-Wiener H' index in Scenarios 1 and 2. The naturalness index showed increased sensitivity in Scenarios 1 and 4. Our future aims are to obtain the DSS for all forest-dwelling bird species, and to adopt the naturalness index to evaluate temporal and spatial changes in biodiversity.