• 한국초전도학회:학술대회논문집
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• 한국초전도학회 1999년도 High Temperature Superconductivity Vol.IX
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• pp.260-260
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• 1999

We compared c-axis tunneling characteristics of small stacked intrinsic Josephson junctions prepared on the surface of pristine, I-, and HgI$_2$-intercalated Bi$_2Sr_2CaCu_2O_{8+x}$ (Bi2212) single crystals. The R(T) curves are almost metallic in I-Bi2212 specimens, but semiconducting in HgI$_2$-Bi2212 ones.· The transition temperatures were 82.0 K, 73.0 K, and 76.8 K for pristine Bi2212, I-Bi2212, and HgI2-Bi2212 specimens, respectively, consistent with p-T$_c$ phase diagram. Current-voltage (IV) characteristics of both kinds of specimens show multiple quasiparticle branches with well developed gap features, indicating Josephson coupling is established between neighboring CuO$_2$ planes. The critical current I$_c$ of I-Bi2212 is almost the same as of that of pristine crystals, but I$_c$ is much reduced in Hgl$_2$-Bi2212. In spite of expanded interlayer distances, the interlayer coupling is not significantly affected in I-Bi2212due to holes generated by iodine atoms. The coupling in HgI$_2$-Bi2212 is, however, weakened due to inertness of HgI$_2$ molecules and the expansion of interlayer distance. Relation between the superconducting transition temperature T$_c$ and the critical current I$_c$ seems to contradict Anderson's interlayer-pair-tunneling theory but agree with a modified version of it.

• BMB Reports
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• 제52권12호
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• pp.689-694
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• 2019

Ethical and safety issues have rendered mesenchymal stem cells (MSCs) popular candidates in regenerative medicine, but their therapeutic capacity is lower than that of induced pluripotent stem cells (iPSCs). This study compared original, dental tissue-derived MSCs with re-differentiated MSCs from iPSCs (iPS-MSCs). CD marker expression in iPS-MSCs was similar to original MSCs. iPS-MSCs expressed higher in pluripotent genes, but lower levels in mesodermal genes than MSCs. In addition, iPS-MSCs did not form teratomas. All iPSCs carried mtDNA mutations; some shared with original MSCs and others not previously detected therein. Shared mutations were synonymous, while novel mutations were non-synonymous or located on RNA-encoding genes. iPS-MSCs also harbored mtDNA mutations transmitted from iPSCs. Selected iPS-MSCs displayed lower mitochondrial respiration than original MSCs. In conclusion, screening for mtDNA mutations in iPSC lines for iPS-MSCs can identify mutation-free cell lines for therapeutic applications.

• Journal of Radiation Protection and Research
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• 제16권2호
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• pp.1-6
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• 1991

상온에서 사용할 수 있는 감마선 검출 소자로서 $HgI_2$ 소자의 응용성을 판단하기 위하여 기상 성장법으로 $HgI_2$ 단결정을 성장시켰고 이를 이용하여 검출 소자를 제작한 후 감마선 검출 특성을 조사하였다 성장된 단결정의 비저항과 전하 운반자 포획 밀도는 상온에서 각각 $10^{11}{\Omega}\;cm$와 $1.8{\times}10^{14}/cm^3$였으며 단결정의 Photoluminescence를 측정한 결과 성장된 $HgI_2$ 단결정의 밴드갭의 온도계수는 20K부터 77K에서 $-1.53{\times}10^{-4}eV/K$였다. 감마선 검출실험 결과 제작된 $HgI_2$ 검출 소자는 상온에서 우수한 계수 특성과 시간에 대한 선형적 축적 계수 특성을 나타내었으나 온도변화에 따라 계수의 특성의 변화는 심하였다.

• 한국산업융합학회 논문집
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• 제10권3호
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• pp.179-185
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• 2007

Quartz glass are used in semiconductor industries as the reaction furnace, wafer carrier and accessaries. During the process the quartz glass received compression by direct contact with other quartz glass ware and metal as the form of weight itself and vacuum pressure and fatigue by vibrations caused by process. Even as the other ceramic materials quartz glass have high compressive strength but often there happened crack and breakage of quartz glass resulted in a great damage in the process. In this paper investigation will be carried out on fracture behavior of quartz glass under local load to give guideline to prevent unintended fracture of quartz glass.

• Korean Journal of Mathematics
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• 제8권1호
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• pp.19-26
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• 2000

In this paper, it is shown that if R is a commutative ring with identity and there exists a multiplicatively closed subset S of R such that $S{\cap}Z(R/(I_1I_2{{\cdots}I_n))={\emptyset}$ and $I_1R_s,I_2R_s{\cdots},I_nR_s$ are pairwise comaximal, then $I_1I_2{\cdots}I_n=I_1{\cap}I_2{\cap}{\cdots}{\cap}I_n={\cap}^n_{i=1}(I_i\;:_R\;I_1{\cdots}I_{i-1}I_{i+1}{\cdots}I_n)$.

• 대한미생물학회지
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• 제22권2호
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• pp.147-153
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• 1987

Colonization factor antigen I(CFA I) has been shown to be one of several virulence factors that promote attachment of enterotoxigenic E. coli(ETEC) to small intestinal epithelial cells of humans. The ability of ETEC to produce mannose-resistant hemagglutination(MRHA) of human blood group A has been used to detect CFA I. To determine gastrointestinal carriage in Korean children of E. coli with MRHA and CFA I, 116 strains of E. coli from diarrheal children admitted to Hanyang University Hospital were examined for MRHA of human erythrocytes and the presence of CFA I. Of 45 ETEC strains, 18(40%) gave a positive MRHA($MRHA^+$) and eight(18%) were positive for CFA I(CFA $I^+$). ETEC with CFA I were all heat-stable enterotoxin(ST) producers and two of these strains were of serogroups $O_{25}$. Of 17 classic enteropathogenic E. coli(EPEC), 7(41%) were $MRHA^+$ but all were negative for CFA I(CFA $I^-$). Of 30 enteroadherent E. coli(EAEC) strains, 11(37%) were $MRHA^+$ and one was CFA $I^+$. Of 24 nonpathogenic E. coli, 4(17%) were $MRHA^+$ but all were CFA $I^-$. It was shown that MRHA was common in all strains of E. coli, CFA I was limited only to ST producing ETEC and EAEC; although MRHA is a useful screening procedure, serologic tests seem to be necessary to comfirm CFA I production. CFA I was associated with a lower proportion of ETEC isolates in Korea than has been reported for other locations.

• 대한수학회지
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• 제54권4호
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• pp.1265-1279
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• 2017

In order to study the structure of arbitrary split Leibniz triple systems, we introduce the class of split Leibniz triple systems as the natural extension of the class of split Lie triple systems and split Leibniz algebras. By developing techniques of connections of roots for this kind of triple systems, we show that any of such Leibniz triple systems T with a symmetric root system is of the form $T=U+{\sum}_{[j]{\in}{\Lambda}^1/{\sim}}I_{[j]}$ with U a subspace of $T_0$ and any $I_{[j]}$ a well described ideal of T, satisfying $\{I_{[j]},T,I_{[k]}\}=\{I_{[j]},I_{[k]},T\}=\{T,I_{[j]},I_{[k]}\}=0 \text{ if }[j]{\neq}[k]$.

• Journal of the Korean Statistical Society
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• 제33권3호
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• pp.313-321
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• 2004

We consider the problem of testing cell probabilities in sparse multinomial data. Aerts et al. (2000) presented T=${{\Sigma}_{i=1}}^{k}{[{p_i}^{*}-E{(p_{i}}^{*})]^2$ as a test statistic with the local least square polynomial estimator ${{p}_{i}}^{*}$, and derived its asymptotic distribution. The local least square estimator may produce negative estimates for cell probabilities. The local maximum likelihood polynomial estimator ${{\hat{p}}_{i}}$, however, guarantees positive estimates for cell probabilities and has the same asymptotic performance as the local least square estimator (Baek and Park, 2003). When there are cell probabilities with relatively much different sizes, the same contribution of the difference between the estimator and the hypothetical probability at each cell in their test statistic would not be proper to measure the total goodness-of-fit. We consider a Pearson type of goodness-of-fit test statistic, $T_1={{\Sigma}_{i=1}}^{k}{[{p_i}^{*}-E{(p_{i}}^{*})]^2/p_{i}$ instead, and show it follows an asymptotic normal distribution. Also we investigate the asymptotic normality of $T_2={{\Sigma}_{i=1}}^{k}{[{p_i}^{*}-E{(p_{i}}^{*})]^2/p_{i}$ where the minimum expected cell frequency is very small.

• 한국미생물·생명공학회지
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• 제15권5호
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• pp.352-355
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• 1987

새로운 제한효소인 Cth I을 Clostridium thermocellum ATCC 27405로부터 분리하여, 그 효소의 생화학적 특성을 연구하였다. 이 효소는 Bcl I endonuclease의 isoschizomer로서 5'-TGATCA-3'를 인식한다. Cth I endonuclease는 섭씨 60도의 높은 온도에서 잘 작용하며, 10mM까지의 저농도의 NaCl과 MG$^{2+}$ 이온의 존재하에서 pH7.5와 10.5사이에서 최적의 활성을 보여주었다. Cth I endonuclease의 활성은 DNA 기질이 dam methylation 되었을 때 저해를 받았다.

• 대한추나의학회지
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• 제2권1호
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• pp.169-175
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• 2001

Objects : The purpose of this study is find out significant (clinical) effect of applying acupuncture on $zh{\grave{a}}h{\grave{a}}i$(K6, 照海) of ${\bar{U}m-kyo-maek$(陰?脈) and $sh{\bar{e}}nm{\grave{a}}i$(B62, 申?) of Yang-kyo-maek(陽?脈) to a patient of circadian sleep disorder. Methods : We apply acupuncture on $zh{\grave{a}}h{\grave{a}}i$(K6, 照海) and $sh{\bar{e}}nm{\grave{a}}i$(B62, 申?) to a patient of circadian sleep disorder during 2 weeks. We check sleeping time day and night during 14 days. Acupuncture on $zh{\grave{a}}h{\grave{a}}i$(K6, 照海) and $sh{\bar{e}}nm{\grave{a}}i$(B62, 申?) has significant effect to circadian sleep disorder patient. Results : Acupuncture on $zh{\grave{a}}h{\grave{a}}i$(K6, 照海) and $sh{\bar{e}}nm{\grave{a}}i$(B62, 申?) has significant effect to circadian sleep disorder patient. Conclusions : 1. The physio-pathologic phenomenon of sleeping is relative to ${\bar{U}m-kyo-maek$(陰?脈) and Yang-kyo-maek(陽?脈) 2. Acupuncture therapy on $zh{\grave{a}}h{\grave{a}}i$(K6, 照海) and $sh{\bar{e}}nm{\grave{a}}i$(B62, 申?) has significant effect to circadian sleep disorder.