• Journal of Environmental Health Sciences
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• v.28 no.2
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• pp.193-202
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• 2002

The polymerase chain reaction(PCR) of target lacZ and uidA genes were used to detect total coliform and Escherichia coli for determining water quality, respectively. Of 109 spring waters, coliform were detected from 38 spring waters by lacZ PCR method but 21 spring waters by culture method accepted by the Ministry of Environment for water quality monitoring. The lacz PCR method gave the results statistically equivalent to those of the culture method(kappa=0.62, McNemar=17.00). The uidA PCR method gave the same results to those of the culture method. The sensitivity and specificity of coliform and E. coli by PCR method were 100% and 80.7%, respectively. Therefore, PCR can be used for the rapid identification of Escherichia coli and coliform in potable water using uidA and lacZ.

• Journal of Hydrogen and New Energy
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• v.15 no.2
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• pp.144-151
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• 2004

The effect of the cobalt content on the thermodynamic and, heat and mass transfer properties of the $MmNi_{5-y}B_{y-z}C_z(y=0.5{\sim}1.5,\;z=0.5)$hydrogen storage alloys has been studied systematically. The P-C isotherms curves show that with increasing cobalt content in the alloys, the plateau pressure of the hydrogen absorption and desorption and enthalpy(${\Delta}H$) increases steeply and the plateau region becomes flat, while entropy(${\Delta}S$) decreases. Also at the constant cobalt content the hydrogen transfer rate decreases with the reaction temperature, while the initial reaction kinetics increases. But the initial reaction with hydrogen completes within 1min, although the reaction proceeds about 30minutes thereafter.

• Bulletin of the Korean Mathematical Society
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• v.51 no.5
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• pp.1485-1502
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• 2014

The explicit formula for the hyperbolic metric ${\lambda}_{{\alpha},{\beta},{\gamma}}(z){\mid}dz{\mid}$ on the thrice-punctured sphere $\mathbb{P}{\backslash}\{0,1,{\infty}\}$ with singularities of order 0 < ${\alpha}$, ${\beta}$ < 1, ${\gamma}{\leq}1$, ${\alpha}+{\beta}+{\gamma}$ > 2 at 0, 1, ${\infty}$ was given by Kraus, Roth and Sugawa in [9]. In this article we investigate the asymptotic properties of the higher order derivatives of ${\lambda}_{{\alpha},{\beta},{\gamma}}(z)$ near the origin and give more precise descriptions for the asymptotic behavior of ${\lambda}_{{\alpha},{\beta},{\gamma}}(z)$.

• Bulletin of the Korean Mathematical Society
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• v.43 no.4
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• pp.723-735
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• 2006

In [2] it was shown that a 1-generator quasi-cyclic code C of length n = ml of index l over $\mathbb{Z}_4$ is free if C is generated by a polynomial which divides $X^m-1$. In this paper, we prove that a necessary and sufficient condition for a cyclic code over $\mathbb{Z}_pk$ of length m to be free is that it is generated by a polynomial which divides $X^m-1$. We also show that this can be extended to finite local rings with a principal maximal ideal.

• Journal of the Korean Mathematical Society
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• v.49 no.1
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• pp.139-151
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• 2012

In the previous paper, we gave a characterization of backward shift invariant subspaces of the Hardy space over the bidisk on which [${S_z}^n$, $S_w^*$] = 0 for a positive integer n ${\geq}$ 2. In this case, it holds that ${S_z}^n=cI$ for some $c{\in}\mathbb{C}$. In this paper, it is proved that if [$S_{\varphi}$, $S_w^*$] = 0 and ${\varphi}{\in}H^{\infty}({\Gamma}_z)$, then $S_{\varphi}=cI$ for some $c{\in}\mathbb{C}$.

• Journal of the Korean Mathematical Society
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• v.50 no.3
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• pp.479-491
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• 2013

Let M be a smooth real hypersurface in complex space of dimension $n$, $n{\geq}3$, and assume that the Levi-form at $z_0$ on M has at least $(q+1)$-positive eigenvalues, $1{\leq}q{\leq}n-2$. We estimate solutions of the local $\bar{\partial}$-closed extension problem near $z_0$ for $(p,q)$-forms in Sobolev spaces. Using this result, we estimate the local solution of tangential Cauchy-Riemann equation near $z_0$ in Sobolev spaces.

• Microbiology and Biotechnology Letters
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• v.21 no.3
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• pp.229-238
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• 1993

An nlp (Ner like protein) gene from E. coli was previously cloned and sequenced. Here we show that expression of the sugar metabolism related genes, lacZ, malQ and malP, increased 2.5-to 8.3-fold in the presence of a plasmid containing the nlp gene. This suggested that the nlp gene could induce maltose- and lactose-metabolism coordinately with crp*1 in the absence of cAMP. Using the nlp-lacZ fusion gene, it was possible to show the promoter of nlp was active in vivo.

• Journal of Astronomy and Space Sciences
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• v.3 no.2
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• pp.81-92
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• 1986

The z-coordinate distribution of cepheids was studied and the finding of Fernie(1968) that the cepheid layer is inclined to ward a formal Galactic plane and the Sun is located above the cepheid plane was confirmed. It was found that the z-distribution fits better to the parabolic form than a barometric form and a scale height of 54 pc was found. The well known phenomenon that the periods of classical cepheids decrease away from the Galactic center was crudely interpreted as due to an age gradient rater than an abundance gradient under the assumption that relations between the period and galactocentric distance, and between the abundance and period are linear.

• Proceeding of EDISON Challenge
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• 2017.03a
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• pp.376-382
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• 2017

Graphene nanoribbons with zigzag-shaped edge (zGNRs) are predicted to be magnetic insulator at the ground state, attracting significant interest in view of spintronic applications [1]. On the other hand, although they are energetically and thermodynamically more favored than zGNRs [2], graphene nanoribbons with armchair-shaped edge (aGNRs) have been less spotlighted than zGNRs due to the absence of magnetism. Herein, based on the combined density functional theory (DFT) and matrix Green's function (MGF) approach, we consider aGNRs functionalized with various molecular groups, and show that the spin polarizations develop for some of the considered aGNR edge functionalization cases. The origin of the induced magnetism will be discussed within the Lieb's theorem [3]. This work will provide a novel guidance for the development of graphene-based spintronic devices.

• Speech Sciences
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• v.13 no.4
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• pp.43-50
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• 2006

The aim of this study was to identify pronunciation difficulties of Korean learners of English in their articulation of English sibilants /dg, g, z/. Forty-five syllables were produced five times by twelve college students. Test scores were measured from the score board made by FluSpeak, a speech training software program, which was designed for English pronunciation practice and improvement. Results show that 1) the subjects had lower scores in producing /g/ than /dg/ and /z/ from all positions, and 2) subjects had lower scores in inter-vocalic position than in pre-vocalic position and in post-vocalic position when they produced /dg/, /g/, and /z/. The results suggest that on the whole Korean learners have much difficulty in producing /g/, and they also have more auditory and articulatory problems in intervocalic than in the other positions when they produce these sibilants.