• Bulletin of the Korean Mathematical Society
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• v.59 no.5
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• pp.1305-1315
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• 2022

Let u be a function on a connected finite graph G = (V, E). We consider the mean field equation (1) $-{\Delta}u={\rho}\({\frac{he^u}{\int_Vhe^ud{\mu}}}-{\frac{1}{{\mid}V{\mid}}}\),$ where ∆ is 𝜇-Laplacian on the graph, 𝜌 ∈ ℝ\{0}, h : V → ℝ⁺ is a function satisfying min_x∈V h(x) > 0. Following Sun and Wang [15], we use the method of Brouwer degree to prove the existence of solutions to the mean field equation (1). Firstly, we prove the compactness result and conclude that every solution to the equation (1) is uniformly bounded. Then the Brouwer degree can be well defined. Secondly, we calculate the Brouwer degree for the equation (1), say $$d_{{\rho},h}=\{{-1,\;{\rho}>0, \atop 1,\;{\rho}<0.}$$ Consequently, the equation (1) has at least one solution due to the Brouwer degree d_𝜌,h ≠ 0.

• Proceedings of the Korean Ceranic Society Conference
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• 2003.10a
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• pp.141.1-141
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• 2003

• Journal of Photoscience
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• v.9 no.2
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• pp.479-481
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• 2002

UV-induced DNA damage causes cell killing and mutations leading to carcinogenesis. In normal human cells, UV damage such as cyclobutane pyrimidine dimers (CPDs) and primidine-prymidone (6-4) photoproducts are mainly repaired by nucleotide excision repair mechanism. The molecular processes have been well characterized recently. To know the influence of mitochondrial genome on the nucleotide excision repair mechanism against CPDs, we comparatively examined the production of CPDs by UVC irradiation and their repair kinetics in human cells completely lacking mitochondrial DNA (mtDNA) and the parental HeLa S cells. Whole DNA extracted from the cells exposed to UVC was treated with T4-endonuclease V to break the phosphodiester bond adjacent to CPDs. The DNA was electrophoresed in a denaturing agarose gel, which was visualized by ethidium bromide staining. The relative amount of CPDs was determined by image analysis using NIH Image software. MtDNA- less (rho-O) cells were apparently more sensitive to UVC than HeLa S cells, while the level of induction of CPDs in rho-O and HeLa cells was comparable. The repair of CPDs was less efficient in rho-O cells compared with HeLa cells. The residual amount of CPDs after 24-h repair was larger in rho-O cells than in HeLa cells where more than 90 % of CPDs were repaired by then. The non-repaired CPDs would lead to apoptosis in rho-O cells. These results suggest that mitochondrial genome may contribute to some ATP-dependent steps in nucletide excision repair by supplying sufficient ATP which is generated through a respiratory chain in mitochondria.

• Bulletin of the Korean Chemical Society
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• v.32 no.5
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• pp.1625-1629
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• 2011

Kinetic studies of the reactions of O,O-diphenyl Z-S-aryl phosphorothioates with X-benzylamines have been carried out in dimethyl sulfoxide at 55.0 $^{\circ}C$. The Hammett (log $k_2$ vs ${\sigma}_X$) and Bronsted [log $k_2$ vs $pK_a(X)$] plots for substituent X variations in the nucleophiles are biphasic concave downwards with a maximum point at X = H, and the unusual positive ${\rho}_X$ and negative ${\beta}_X$ values are obtained for the strongly basic benzylamines. The sign of the cross-interaction constant (${\rho}_{XZ}$) is negative for both the strongly and weakly basic nucleophiles. Greater magnitude of ${\rho}_{XZ}$ value is observed with the weakly basic nucleophiles (${\rho}_{XZ}$ = -2.35) compared to with the strongly basic nucleophiles (${\rho}_{XZ}$ = -0.03). The deuterium kinetic isotope effects ($k_H/k_D$) involving deuterated benzylamines [$XC_6H_4CH_2ND_2$] are primary normal ($k_H/k_D$ > 1). The proposed mechanism is a concerted $S_N2$ involving a frontside nucleophilic attack with a hydrogen bonded, four-center-type transition state for both the strongly and weakly basic nucleophiles. The unusual positive ${\rho}_X$ and negative ${\beta}_X$ values with the strongly basic benzylamines are rationalized by through-space interaction between the ${\pi}$-clouds of the electron-rich phenyl ring of benzylamine and the phenyl ring of the leaving group thiophenoxide.

• Journal of the Korean Chemical Society
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• v.31 no.2
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• pp.190-196
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• 1987

The structure of 9-barbaralyl cation was examined by Hammett-Brown plot using $^{13}C$ NMR chemical shifts. 9-Aryltricylclo$[3.3.1.0^{2,8}]$]nonan-9-yl cation (5) and 9-aryltricyclo-$[3.3.1.0^{2,8}]$nona-3,6-dien-9-yl cation (6) were prepared from the corresponding carbinols in $FSO_3H-SO_2ClF$ solution at -$120^{\circ}C$, and their chemical shifts of cation centers were measured. The slopes, ${\rho}^{C+}$ values, of the Hammett-Brown plot of (5) and (6) were -5.01 and -7.52, respectively. From these values themselves, it seemed that the double bonds participated in the delocalization of the positive charge. However, comparing ${\rho}^{C+}$ value and ${\rho}^{C_a^+}$ value in 9-barbaralyl cation (6) and those in 8,9-dehydroadamantyl cation (7), we concluded that 9-barbaralyl should be represented by the structure 4 shown in Scheme I.

• Transactions of the Korean Society of Mechanical Engineers
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• v.11 no.6
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• pp.1001-1004
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• 1987

In this study mathematical properties of variational solution and solution of the boundary integral equation of the linear elasticity problem are studied. It is first reviewed that a variational solution for the three-dimensional linear elasticity problem exists in the Sobolev space [ $H^{1}$(.OMEGA.)]$^{3}$ and, then, it is shown that a unique solution of the boundary integral equation is identical to the variational solution in [ $H^{1}$(.OMEGA.)]$^{3}$. To represent the boundary integral equation, the Green's formula in the Sobolev space is utilized on the solution domain excluding a ball, with small radius .rho., centered at the point where the point load is applied. By letting .rho. tend to zero, it is shown that, for the linear elasticity problem, boundary integral equation is valid for the variational solution. From this fact, one can obtain a numerical approximatiion of the variational solution by the boundary element method even when the classical solution does not exist.exist.

• The Journal of Korean Physical Therapy
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• v.28 no.5
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• pp.328-333
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• 2016

Purpose: This study was to investigate the correlation between pain, disability and quality of life among adolescents and office workers with neck and shoulder pain. Methods: Twenty-four subjects (mean age=24.92 years, SD=3.94, range=20-37) with neck and shoulder pain participated in this study. The outcome measures of the study were visual analogue scale (VAS), neck disability index (NDI), shoulder pain and disability index (SPADI), short form-36 (SF-36) for neck and shoulder pain and disability, quality of life. Pearson's correlation and Speaman's rank correlation were used to measure the association between VAS and NDI, SPADI, SF-36. Results: The VAS showed a positive correlation between weak to moderate with the NDI and SPADI, but no significantly correlated (${\rho}=0.34$, ${\rho}=0.25$). The moderate positive correlation and significant correlation were observed between NDI and SPADI (${\rho}=0.43$, p<0.05). The PCS of SF-36 was significantly negative correlated with the VAS (${\rho}=-0.24$), NDI and SPADI (${\rho}=-0.63$, ${\rho}=-0.59$, p<0.05). Conclusion: The pain and disability of neck and shoulder has closely relevance. And, the pain and disability of neck and shoulder has a negative impact on the quality of life.

• Journal of the Korean Society of Food Science and Nutrition
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• v.26 no.2
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• pp.248-253
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• 1997

The paper describes the activation mode and the glycosic linkage of anti-complementary polysaccharide isolated from Cinnamomum cassia. The polysaccharide fractions, CC-IIIa, CC-IIIb, and CC-IIIc, activated C3 component existed in normal human serum and produced C3 cleavage segments, C3a and C3b. The polysaccharide, CC-2-IIIa-3 activated the complement system both in the presence and absence of $Ca^{++}$, suggesting that it involved in both classical and alternative complement pathways. Methylation of CC-2-IIIa-3 was performed with methylsulphinyl carbanion and methyl iodide in DMSO. The methylated products was hydrolyzed, then converted into the partially methylated alditol acetates. Gas chromatography-mass spectrometry(GC-MS) revealed derivatives of terminal $Glc{\rho}$ and $Gal{\rho}$, 1,2-linked $Rha{\rho}$, 1,6-linked $Man{\rho}$, 1,3-linked $Glc{\rho}$, 1,6-linked $Gal{\rho}$ etc.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.21 no.7
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• pp.638-644
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• 2008

The effects of $Nb_2O_5$ and $MnO_2$ on the positive temperature coefficient of resistivity (PTCR) behavior of lead-free $Ba_{0.99}(Bi_{1/2}Na_{1/2})_{0.01}TiO_3$ (BaBiNT) ceramics were investigated in order to fabricate a PTC thermistor available at high temperature of > $120^{\circ}C$. In particular, 0.05 mol% $Nb_2O_5$ added BaBiNT ceramic, which has significantly increased Curie temperature (Tc) of $160^{\circ}C$, showed good PTCR behavior; low resistivity at room temperature $(\rho_r)$ of $80.1{\Omega}{\cdot}cm$, a high $\rho_{max}/\rho_{min}$ ratio of $5.65{\times}10^3$ and a large resistivity temperature factor (a) of 18.5%/$^{\circ}C$. Furthermore, the improved $\rho_{max}/\rho_{min}$ of $6.48{\times}10^4$ and a of 25.4%/$^{\circ}C$ along with higher $T_c$ of $167^{\circ}C$ despite slightly increased $\rho_r$ of $569{\Omega}{\cdot}cm$, could be obtained for the BaBiNT + 0.05 mol% $Nb_2O_5$ + 0.02 wt% $MnO_2$ ceramic cooled down at a rate of $200^{\circ}C/h$.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2003.06a
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• pp.764-767
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• 2003

The characteristics of diesel spray have much effect on the engine performances such as power. fuel consumption rate and emissions. Therefore, the measurement of fuel spray characteristics is very important for the improvement of heat engine. The factors which control diesel spray characteristics are injection pressure, ambient temperature and density etc. Spray behaviors are visualized by using the high speed video camera and spray angle, spray penetration are measured. Experimental equations of spray penetration and spray angle were derived by using the experimental results. 1) Ambient temperature and density influence on the characteristics of diesel spray. 2) Experimental equation of spray penetration is expressed as follows 0＜t＜ $t_{b}$ ; $S_1$=11.628$\Delta$ $P^{0.485}$ $\rho$$_{a}$ $^{-0.478}$ $t^{1.337}$, $t_{b}$ ＜t; $S_2$=7.457$\Delta$ $P^{0.523}$ $\rho$$_{a}$ $^{-0.382}$ $t^{0.548}$ 3) Experimental equation of spray Angie is expressed as follows $T_{a}$ =293K; Tan($\theta$/2)=059($\rho$$_{a}$ / $\rho$$_{f}$ )$^{0.437}$, $T_{a}$ =473K; Tan($\theta$/2)=0588($\rho$$_{a}$ / $\rho$$_{f}$ )$^{0.404}$_{f}$ )$^{0.404}$