• Journal of applied mathematics & informatics
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• v.30 no.3_4
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• pp.455-462
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• 2012

The cyclic group $Cn={\langle}(12{\cdots}n){\rangle}$ acts on the set ($^{[n]}_k$) of all $k$-subsets of [$n$]. In this action of $C_n$ the number of orbits of size $d$, for $d|n$, is $$O^{n,k}_d=\frac{1}{d}\sum_{\frac{n}{d}|s|n}{\mu}(\frac{ds}{n})(^{n/s}_{k/s})$$. Stanton and White[7] generalized the above identity to construct the orbit polynomials $$O^{n,k}_d(q)=\frac{1}{[d]_{q^{n/d}}}\sum_{\frac{n}{d}|s|n}{\mu}(\frac{ds}{n})[^{n/s}_{k/s}]{_q}^s$$ and conjectured that $O^{n,k}_d(q)$ have non-negative coefficients. In this paper we give a combinatorial proof for the positivity of coefficients of the orbit polynomial $O^{n,3}_d(q)$.

• Korean Journal of Mathematics
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• v.25 no.3
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• pp.349-358
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• 2017

The cyclic group $C_n={\langle}(12{\cdots}n){\rangle}$ acts on the set $(^{[n]}_k)$ of all k-subsets of [n]. In this action of $C_n$ the number of orbits of size d, for d | n, is $$O^{n,k}_d={\frac{1}{d}}{\sum\limits_{{\frac{n}{d}}{\mid}s{\mid}n}}{\mu}({\frac{ds}{n}})(^{n/s}_{k/s})$$. Stanton and White [6] generalized the above identity to construct the orbit polynomials $$O^{n,k}_d(q)={\frac{1}{[d]_{q^{n/d}}}}{\sum\limits_{{\frac{n}{d}}{\mid}s{\mid}n}}{\mu}({\frac{ds}{n}})[^{n/s}_{k/s}]_{q^s}$$ and conjectured that $O^{n,k}_d(q)$ have non-negative coefficients. In this paper we give a constructive proof for the positivity of coefficients of the orbit polynomial $O^{n,2}_d(q)$.

• Bulletin of the Korean Chemical Society
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• v.22 no.12
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• pp.1333-1336
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• 2001

A theoretical analysis is presented for the multichannel type resonance at energies above the dissociation threshold to O(1D) in the photodissociation of OH. Dissociations to both oxygenic terms O(3P) and O(1D) are treated. Total cross sections for producing these oxygen terms display asymmetric resonance due to the quantum interference resulting from complicated interplay of electronic states correlating to these two oxygenic terms. The branching ratios of O(3Pj, j = 0, 1, 2), and the vector properties of O(3Pj, j =0,1,2) and O(1D) display extensive changes near the threshold resonance as the result of the interactions among the electronic states correlated with O(3P) and O(1D).

• Proceedings of the Korean Vacuum Society Conference
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• 2011.02a
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• pp.333-333
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• 2011

We studied the H/D exchange kinetics of pure and acid dopped water-ice film by using the techniques of reactive ions scattering (RIS) and low energy sputtering (LES) with low kinetic energy cesium ion beam (<35 eV). From RIS, neutral water isotopomers were detected in the form of cesium-molecule ion clusters, $CsX^+$ (X= $H_2O$, HDO, $D_2O$). Ionic species, like $H_3O^+$, $DH_2O^+$, $D_2HO^+$, $D_3O^+$, adsorbed on the surface were ejected via LES process. Those techniques allowed us to trace the isotopomeric populations of water-ice film. To show the catalytic effect of excess proton in the H/D exchange reaction, our study was conducted with two types of water-ice films. In film 1, about 0.5 BL of $H_2O$ was adsorbed on HCl (0.1 ML) dopped $D_2O$ (8 BL) film. In film 2, similar amount of $H_2O$ used in film 1 was adsorbed on pure $D_2O$ film. Kinetic data were obtained from each film type for 90-110 K (film 1) and 110-130 K (film 2) and fitted with numerically integrated lines. Through the Arrhenius plot of kinetic coefficient deduced from fitting of the H/D exchange reaction, the activation energy of film 1 and 2 were estimated to be $10{\pm}3kJmol^{-1}$ and $17{\pm}4kJmol^{-1}$. This activation barrier difference could be understood from detailed pictures of H/D exchange. In film 2, both the formation of ion pair, $H_3O^+$ and OH. and proton transfer were needed for the H/D exchange. However, in film 1, only proton transfer was necessary but ion pair formation was not, so this might reduce the activation energy.

• Animal Systematics, Evolution and Diversity
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• v.11 no.2
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• pp.207-221
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• 1995

Electrophoretic analysis was performed to determine the interspecific genetic relationships of the genus Raja collected in Korea waters. We confirmed 5 species [Raja (Okamejei) meerdervoortii Bleeker, R.(O).acutispina Ishiyama, R.(O) kenojei Muller et Henle, Raja (Dipturus) kwangtungensis Chu, and R.(D.) pulchra Liu] inhabting in Korea. As results of starch gel electrophoresis, 24 genetic loci were obtained from 13 enzymic and non-enzymic proteins, and allele frequencies of each locus were calculated . Even thought their various dorsal color patterns, the mean genetic similarity among 4 conspecific populations of R.(O) kenojei showed highly close genetic relationships (S=0.966) R.(O) kenojei and R.(D) kwangtungensis which belong to different subgenus , revealed subspecific level of differentiation (S=0.829). R. (Diptuuus ) kwangtungensis was genetically much closer to Raja(Okamejei) species than to Raja (Dipturus) species group. R.(O) acutispina and R.(D) kwangtungensis were unrecorded species to Korea.

• Natural Product Sciences
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• v.18 no.4
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• pp.273-278
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• 2012

Further phytochemical investigation on the whole plant of Thyrsanthera suborbicularis, collected in Cambodia, led to kaempferol (1), vitexin (2), apigenin-7-O-neohesperidoside (3), chrysoeriol-7-O-${\beta}$-D-glucopyranoside (4), isorhamnetin 3-O-rutinoside (5), kaempferol-3-O-[${\alpha}$-L-rhamnopyranosyl-(13)-${\alpha}$-L-rhamnopyranosyl-(16)-${\beta}$-D-galactopyranoside (6), kaempferol-3-O-${\alpha}$-L-rhamnopyranosyl(12)-O-[${\alpha}$-L-rhamnopyranosyl (16)]-${\beta}$-D-glucopyranoside (7), kaempferol-3-O-[6"-O-(E)-p-coumaroyl]-${\beta}$-D-glucopyranoside (8), kaempferol-3-O-[6"-O-(E)-p-coumaroyl]-${\beta}$-D-galactopyranoside (9), and amentoflavone (10). All the structures were confirmed by the interpretation of NMR (1D and 2D) and MS data, and comparison with the published values. Of the isolated compounds 1 - 10, compounds 8 and 10 displayed the inhibitory activity against NO production in LPS-induced Raw 264.7 cells with $IC_{50}$ values, 3.56 and $15.73{\mu}M$, respectively.

• Bulletin of the Korean Chemical Society
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• v.21 no.6
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• pp.562-566
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• 2000

$\beta-D-Mannopyranosyl$ disaccharides have been obtained from the coupling of 4,6-O-benzylidene derivatives of ethylthio $\alpha-D-mannopyranoside$ employing NIS-TfOH promoter. NIS-TfOH promoted couplings of the corresponding ethylthio $\beta-D-glucopyranoside$ and produced $\alpha-D-glucopyranosyl$ disaccharides. IDCP (iodonium dicollidine perchlorate) was inactive toward the 4,6-O-benzylidenated ethylthio glucopyranosyl donor. However,lDCP coupled the 4,6-O-benzylidenated $ethylthio-\beta-D-galactopyranoside$ to give a-D-galactopyranosyl disaccharides.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.16 no.12
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• pp.1071-1076
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• 2003

The nonlinear properties and their stability of ZPCCD- based varistors, which are composed of ZnO P $r_{6}$ $O_{ll}$ - CoO-C $r_2$ $O_3$-D $y_2$ $O_3$-based ceramics, were investigated in the D $y_2$ $O_3$ content range of 0.0∼2.0 mol%. The incorporation of D $y_2$ $O_3$ greatly affected the nonlinear properties and the best nonlinearity was obtained from 0.5 mol% D $y_2$ $O_3$ with nonlinear exponent of 66.6 and leakage current of 1.2 $\mu$A. Further addition of D $y_2$ $O_3$ deteriorated the nonlinear properties. In stability against DC accelerated aging stress state: 0.95 $V_{1mA}$/15$0^{\circ}C$/24 h, the 0.5 mol％ D $y_2$ $O_3$-doped varistor exhibited the highest stability, in which the variation rate of varistor voltage and nonlinear exponent are -1.9% and 10.5%, respectively. The remainder varistors resulted in thermal runaway due to low density of ceramics.s.s.

• YAKHAK HOEJI
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• v.39 no.2
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• pp.141-147
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• 1995

Four steroids have been isolated from the subterranean parts of Smilax nipponica Miquel (Liliaceae). The structures of these compounds were characterized on the basis of chemical and speectral data. They were $\beta$-sitosterol, $\beta$-sitosterol-3-O-$\beta$-D-glucopyranoside, neotigogenin-3-O-$\beta$-D-glucopyranoside and a new steroidal saponin designated as smilanippin A which was elucidated as neotigogenin-3-O-$\beta$-D-fucopyranosyl(1$\rightarrow$6)-$\beta$-D-glucopyranos ide.

• Korean Journal of Pharmacognosy
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• v.23 no.4
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• pp.221-224
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• 1992

From the roots of Angelica dahurica Bentham et Hooker(Umbelliferae), three coumarin glycosides have been isolated and identified as skimmin, $8-O-{\beta}-D-glucopyranosyl$ xanthotoxol and $tert.-O-{\beta}-D-glucopyranosyl-heralenol$. $8-O-{\beta}-D-Glucopyranosyl-xanthotoxol$ was isolated for the first time from plant source.