• The Korean Journal of Mycology
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• v.16 no.1
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• pp.41-48
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• 1988

To investigate germination characteristics of soils on Fusarium species under different soil conditions, this study was carried out to test spore germination of 4 Fusarium species. Among 102 soil samples, spore germinations of Fusarium solani f. sp. pisi, F. oxysporum f. sp. cucumerium, F. oxysporum f. sp. raphani and F. coccophilum were under 50% in 98, 85, 82 and 83 soil samples, respectively. The highest spore germination of F. solani f. sp. pisi, F. oxysporum f. sp. cucumerium and F. coccophilum was obtained in 21 soil samples of pH 5.1-6.0, whereas F. oxysporum f. sp. raphani was in 33 soil samples of pH 4.1-5.0. The highest spore germination of F. solani f. sp. pisi, F. coccophilum and F. oxysporum f. sp. cucumerium was obtained in 4 soil samples holding soil moisture content of 41-60%, while F. oxysporum f. sp. raphani was in 22 soil samples of 21-30%. F. oxysporum f. sp. raphani only showed a direct correlation(r=0.29) between spore germination and soil moisture content. On the basis of each spore germination in cultivated and non-cultivated soils, there was significant difference(p=0.01) in 4 Fusarium species. F. solani f. sp. pisi only indicated significant difference(p=0.0l) between two contrasting-soils, cultivated and non-cultivated soils. The numbers of microbial population were higher in soils suppressive to spore germination than soils conducive to spore germination.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.57 no.2
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• pp.188-194
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• 2012

This study was carried out to evaluate the quality properties, fatty acid composition and amino acid composition of major Korean inbred lines and hybrids of maize for corn breeding. Protein content of $F_2$ seeds was 9.0%, which was slightly lower than those of inbred lines, 11.4%, and $F_1$ seeds, 10.9%. in hybrid maizes. Lipid content of $F_2$ seeds of hybrid maizes was 4.2%, slightly higher than those of inbred lines, 3.3%, and $F_1$ seeds, 3.6%. However, there was no significant difference in ash content. The amount of linoleic acid in inbred lines, $F_1$ and $F_2$ seeds of hybrid maizes was highest among all fatty acids and followed by oleic acid, palmitic acid, stearic acid and linolenic acid. The composition of saturated fatty acid of $F_2$ seeds was 17.6%, similar to $F_1$ seeds but it was lower than that of inbred lines. The composition of unsaturated fatty acid of $F_2$ seeds was 82.4%, similar to $F_1$ seeds but was higher than inbred lines. The content of leucine of $F_2$ seeds was lower than inbred lines and $F_1$ seeds. The content of valine, serine, threonine, cysteine, aspartic acid, lysine, arginine, histidine of $F_2$ seeds was higher than inbred lines and $F_1$ seeds. MMA (monoamino monocarboxylic acid) in inbred lines, $F_1$ and $F_2$ seeds of hybrid maizes was highest among all amino acids and followed by DMA (diamino monocarboxylic acid) and AAA (aromatic amino acid).

• Korean Journal of Agricultural and Forest Meteorology
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• v.17 no.3
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• pp.227-235
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• 2015

Using eddy covariance method, net ecosystem exchange (NEE) of $CO_2$ ($F_{CO_2}$), $H_2O$ (LE), and sensible heat (H) can be approximated as the sum of eddy flux ($F_c$) and storage flux term ($F_s$). Depending on strength and distribution of sink/source of scalars and magnitude of vertical turbulence mixing, the rates of changes in scalars are different with height. In order to calculate $F_s$ accurately, the differences should be considered using scalar profile measurement. However, most of flux sites for agricultural lands in Asia do not operate profile system and estimate $F_s$ using single-level scalars from eddy covariance system under the assumption that the rates of changes in scalars are constant regardless of the height. In this study, we measured $F_c$ and $F_s$ of $CO_2$, $H_2O$, and air temperature ($T_a$) using eddy covariance and profile system (i.e., the multi-level measurement system in scalars from eddy covariance measurement height to the land surface) at the Chengmicheon farmland site in Korea (CFK) in order to quantify the differences between $F_s$ calculated by single-level measurements ($F_s_{-single}$ i.e., $F_s$ from scalars measured by profile system only at eddy covariance system measurement height) and $F_s$ calculated by profile measurements and verify the errors of NEE caused by $F_s_{-single}$. The rate of change in $CO_2$, $H_2O$, and Ta were varied with height depending on the magnitudes and distribution of sink and source and the stability in the atmospheric boundary layer. Thus, $F_s_{-single}$ underestimated or overestimated $F_s$ (especially 21% underestimation in $F_s$ of $CO_2$ around sunrise and sunset (0430-0800 h and 1630-2000 h)). For $F_{CO_2}$, the errors in $F_s_{-single}$ generated 3% and 2% underestimation of $F_{CO_2}$ during nighttime (2030-0400 h) and around sunrise and sunset, respectively. In the process of nighttime correction and partitioning of $F_{CO_2}$, these differences would cause an underestimation in carbon balance at the rice paddy. In contrast, there were little differences at the errors in LE and H caused by the error in $F_s_{-single}$, irrespective of time.

• Journal of applied mathematics & informatics
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• v.7 no.2
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• pp.693-701
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• 2000

In this paper, we investigate a generalization of the Ulam stability problem of the 3-dimensional Euler-Lagrange functional equation f(x-y-z)+f(x)+f( y)+f(z)= f(x-y) +f(y+z) +f(z-x)

• Bulletin of the Korean Mathematical Society
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• v.39 no.2
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• pp.199-209
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• 2002

In this paper, we investigate the problem of stability of the quadratic functional equation f(x+y+z)+f(y-z)+f(y-z)+f(x-z) = 3f(x)+3f(y)+3f(z) on abelian group.

• Communications of the Korean Mathematical Society
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• v.12 no.4
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• pp.851-854
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• 1997

In this paper we will show that the pure subring R of F-rational ring S is F-rational when R is a one-dimensional ring, or S is a Gorenstein ring. And we will give a condition that a pure subring of an F-rational ring is to be F-rational.

• Bulletin of the Korean Mathematical Society
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• v.37 no.3
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• pp.477-486
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• 2000

In this paper, we investigate the Hyers-Ulam-Rassias stability of a quadratic functional equation f(x+y+z)+f(x+y)+f(y-z)+f(z-x)=3f(x)+3f(y)+3f(z) and prove the Hyers-Ulam stability of the equation on restricted (unbounded) domains.

• Bulletin of the Korean Mathematical Society
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• v.33 no.4
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• pp.531-536
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• 1996

Let $F$ denote $R$ or $C$. Put $A = SL(2, F)$. Define $P(F^2)$ to be the set of all 1-dimensional subspaces of $F^2$. Then the natural action of A on $F^2$ induces an action on $P(F^2)$.

• Journal of the East Asian Society of Dietary Life
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• v.11 no.4
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• pp.274-280
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• 2001

The chemical forms of calcium compounds in perilla leaves and their changes after harvest were investigated. The four types of calcium compounds extracted were as follows: water soluble calcium(F-I: mainly water soluble organic acid salts and calcium ion), IN-sodium chloride soluble calcium(F-II: calcium-pectate and calcium-carbonate), 2%-acetic acid soluble calcium(F-III: calcium-phosphate), and 5%-hydrochloric acid soluble calcium(F-IV: calcium-oxalate). The calcium content of perilla leaves was not found to vary with their age. Relatively high levels of F-l (28.4~39.5) and F-II (34.4~47.4) were found in young and mature leaves while the F-IV constituted 15.6~21.6% of the total calcium. The F-IV calcium contents of perilla. spinach and jaso were 16.8, 42.4 and 22.3%, respectively. In contrast to calcium. magnesium existed as water soluble magnesium at the highest content of 90.6% in spinach while 62.9% and 16.8% of the total magnesium existed as water soluble magnesium in perilla and jaso, repectively. The change in vitamin C and F-IV calcium content were examined for 7 days after harvest. Vitamin C content decreased slowly at the beginning but rapidly from the 4th day after harvest. On the other hand, the F-IV calcium content increased slowly at the beginning and rapidly from the 4th day of observation. This result suggests that the increase in F-IV calcium is related to the decrease in vitamin C content. This phenomena was more distinctly observed at 2$0^{\circ}C$ than 5$^{\circ}C$.

• Journal of the Microelectronics and Packaging Society
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• v.10 no.2
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• pp.13-17
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• 2003

In this study, new LTCC materials of $ZnWO_4$-LiF system were developed for the application to RF Module fabrication. Pure $ZnWO_4$ must be sintered above $1050^{\circ}C$ in order to obtain up to 98% of full density. The measured dielectric constant ($\epsilon_r$)quality factor ($Q{\times}f0$), and temperature coefficient of resonant frequency ($\tau_f$ were 15.5, 74000 GHz, and $-70ppm^{\circ}C$, respectively. LiF addition resulted in a liquid phase formation at 81$0^{\circ}C$ due to interaction between ZnWO$_4$ and LiF. Therefore, ZnWO$_4$ with 0.5∼1.5 wt% LiF could be densified at $850^{\circ}C$. In the given LiF addition range, the sintering shrinkage increased with increasing LiF content. Addition of LiF slightly lowered the dielectric constant from 15.5 to 14.2∼15 due to lower dielectric constant of LiF. Qxfo value decreased with increasing LiF content. This can be explained in terms of the interaction between LiF and $ZnWO_4$, and inhomogeneity of grain structure.