• 대한수학회지
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• 제36권3호
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• pp.459-467
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• 1999

A complete analysis of the equation x'=y, y'=$\beta$y-$\alpha$x2+$\alpha$x2+$\delta$xy, where $\alpha$ and $\beta$ small, describing a particular unfolding of the Takens-Bogdanov singularity is presented.

• 대한수학회지
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• 제52권4호
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• pp.751-763
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• 2015

Let ${\alpha}$ be a positive integer, and let $p_1$, $p_2$ be two distinct prime numbers with $p_1$ < $p_2$. By using elementary methods, we give two equivalent conditions of all even near-perfect numbers in the form $2^{\alpha}p_1p_2$ and $2^{\alpha}p_1^2p_2$, and obtain a lot of new near-perfect numbers which involve some special kinds of prime number pairs. One kind is exactly the new Mersenne conjecture's prime number pair. Another kind has the form $p_1=2^{{\alpha}+1}-1$ and $p_2={\frac{p^2_1+p_1+1}{3}}$, where the former is a Mersenne prime and the latter's behavior is very much like a Fermat number.

• 생약학회지
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• 제7권4호
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• pp.237-240
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• 1976

To investigate the constituents of following plants, Valeriana fauriei species, which are V. fauriei var. fauriei $H_{ARA}$, V. fauriei form. coreana $H_{ARA}$ and V. fauriei var. dasycarpa $H_{ARA}$, we carried out gas-liquid chromatographical analysis of the volatile oils of these plants and found that camphene, l-bornylacetate, ${\alpha}-pinene,\;{\beta}-pinene$, d,l-limonene, l-borneol and ${\alpha}-kessylacetate$ were common components in their volatile oils. However, their terpenoidal composition was considerably different from ${\alpha}-kessylacetate$ in V. faurie var. fauriei, from kessanol, ledol, kessoglycol and nardol in V. fauriei var. dasycarpa, and from kessoglycoldiacetate, ${\alpha}-kessylalcohol$, faurinone and terpineol in V. faurie form. coreana. It was found by gas-liquid chromatography that the terpenoidal patterns of these Korean valerians were similar to those of Japanish valerians.

• 천문학회지
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• 제14권2호
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• pp.89-93
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• 1981

Weibull analyses given to the initial mass function (IMF) deduced by Miller and Scalo (1979) have shown that the mass dependence of IMF is an exp$[-{\alpha}m]$- form in low mass range while in the high mass range it assumes an exp$[-{\alpha}\sqrt{m}]/\sqrt{m}$-form with the break-up being at about the solar mass. Various astrophysical reasonings are given for identifying the exp$[-{\alpha}m]$ and exp$[-{\alpha}\sqrt{m}]/\sqrt{m}$ with halo and disk star characteristics, respectively. The physical conditions during the halo formation were such that low mass stars were preferentially formed and those in the disk high mass stars favoured. The two component nature of IMF is in general accord with the dichotomies in various stellar properties.

• 한국환경과학회지
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• 제11권9호
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• pp.829-842
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• 2002

The purpose of this study was to design a reliable and valid Likert-type scale to measure nuclear energy attitudes of various groups. 8 tests were applied to the construction of a 26-item long form, a 12-item middle form, and a 6-item short form of the scale. Three scales were field tested on 760 respondents representing a diverse range of subjects. The 26-item scale appeared to be reliable, content valid and construct valid. Scale reliability and homogeneity were evidenced by 0.95 coefficient alpha and positive interitem correlations ranging from 0.18 to 0.74. The results of factor analysis and known-groups comparison revealed that this scale had high validity. Reliability of the middle form and short form were evidenced by coefficient alpha of 0.92 and 0.90 respectively. The long and middle forms were strongly correlated, r-value of 0.98 and the long and short forms were also highly correlated, r-value of 0.93. Consequently, long form, middle form and short form scales were evidenced very reliable and valid in measuring nuclear energy attitudes of various groups in general. They can be used for a variety of purpose of measuring and testing nuclear energy attitude.

• Journal of Microbiology and Biotechnology
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• 제12권4호
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• pp.610-616
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• 2002

The growth-inhibiting effects of Pinus densiflpora leaf-derived materials on nine human intestinal bacteria were investigated using the impregnated paper disk method, and their activities were compared with those of 13 commercially available terpenes. The biologically active constituent of the extract of P densiflora leaf was characterized as the monoterpene (1R)-(+)-$\alpha$-pinene by various spectroscopic analyses. Responses varied according to bacterial strain, chemicals, and dose. At 10 mg/disk, limonene and (1R)-(+)-$\alpha$-pinene strongly inhibited the growth of Clostridium perfringens, Staphylococcus aureus, and Escherichia coli, without adverse effects on the growth of five lactic acid-bacteria (Bifidobacterium adolescentis, B. bifidum, B. longum, Lactobacillus acidophilus, and L. casei). Little or no inhibition against seven bacteria was observed with anethole, borneol, camphor, caryophyllene, 1,8-cineole, estragole, linalool, and $\alpha$-terpineol. Structure-activity relationship revealed that (1R)-(+)-$\alpha$-pinene had more growth-inhibiting activity against C. perfringens than (1R)-(+)-$\beta$-, (1S-(-)-$\alpha$-, and (1S-(-)-$\beta$-pinenes. Furthermore, the growth-inhibition against L. casei was much more pronounced in (1R)-(+)-$\beta$- and (In-(-)-$\beta$-pinenes than (1R)-(+)-$\alpha$- and (1S)-(-)-$\alpha$-pinenes. These results indicate that the (+)-$\alpha$ form seems to be required against C. perfringens and $\beta$ form against L. casei for growth-inhibiting activity. Morphologically, most strains of C. perfringens were damaged and disappeared at 5 and 2 mg/disk of (1R)-(+)-$\alpha$-pinene. Morphological study revealed that (1R)-(+)-$\alpha$-pinene had more growth-inhibiting activity against C. perfringens than (1R)-(+)-$\beta$-, (1S)-(-)-$\alpha$-, and (1S)-(-)-$\beta$-pinenes. As naturally occurring growth-inhibiting agents, the Pinus leaf-derived materials described above could be useful preventive agents against diseases caused by harmful intestinal bacteria such as clostridia.

• 대한수학회보
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• 제54권2호
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• pp.399-416
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• 2017

In this paper, we study a class of Finsler metrics called general (${\alpha},{\beta}$)-metrics, which are defined by a Riemannian metric ${\alpha}$ and a 1-form ${\beta}$. We show that every general (${\alpha},{\beta}$)-metric with isotropic Berwald curvature is either a Berwald metric or a Randers metric. Moreover, a lot of new isotropic Berwald general (${\alpha},{\beta}$)-metrics are constructed explicitly.

• Archives of Pharmacal Research
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• 제14권2호
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• pp.160-164
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• 1991

The existence in nature of two isomers of 28-nortriterpenes is known. One is normal D/E cis form and the other is $17\alpha$-hydrogen D/E trans form. Since the latter cannot exist with ring D in the chair conformation, the chiroptical method is not applicable to determination of the absolute configuration. The stereochemical assignment would now be made by NMR data. Confirmation of this view could be provided by the synthesis of $3\beta, 21\beta-{dihydroxy-16-keto-28-nor-17}\alpha, \;18\beta-{olean-12-ene}$ as a model compound.

• 대한수학회보
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• 제37권2호
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• pp.337-346
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• 2000

The geodesic equation in a two-dimensional Finsler space is given by the differential equation of the Weierstrass form. In the present paper, we express the differential equations of geodesics in a two-dimensional Finsler space with a generalized Kropina metric.

• 대한수학회보
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• 제56권2호
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• pp.407-418
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• 2019

In this paper, we study conformal transformations between special class of Finsler metrics named C-reducible metrics. This class includes Randers metrics in the form $F={\alpha}+{\beta}$ and Kropina metric in the form $F={\frac{{\alpha}^2}{\beta}}$. We prove that every conformal transformation between locally dually flat Randers metrics must be homothetic and also every conformal transformation between locally dually flat Kropina metrics must be homothetic.