• Journal of the Society of Cosmetic Scientists of Korea
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• v.35 no.3
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• pp.193-202
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• 2009

This study was done to assess an alternative method as a replacement of in vivo phototoxicity test. The human fibroblasts were exposed to several phototoxic chemicals (promethazine, chlorpromazine chlortetracycline, 8-methoxypsoralen, neutral red, bithionol) and non-phototoxic materials (cinnamic aldehyde, p-aminobenzoic acid, sodium lauryl sulfate, L-cysteine). The cell viability was measured by neutral red uptake (NRU) assay. The results of the NRU phototoxicity (PT) assay showed a close agreement with in vivo test except bithionol. We also have tested the cosmetic ingredients including $Medimin^{(R)}$ A, $Medimin^{(R)}$ D, $LG^{(R)}$ 106W, $Phytoclear^{(R)}$ EL-1, Carex humilis L. extract, Canna indica L. extract, Salvia miltiorrhira Bunge extract, $Parsol^{(R)}$ MCX and $Parsol^{(R)}$ 1789. Most materials except Salvia miltiorrhira Bunge extract did not show any phototoxicity.

• Solar Energy
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• v.20 no.4
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• pp.25-30
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• 2000

The present study has been conducted to offer an geometrically optimal structure of a storage tank for a regenerator. In this paper, three kinds of baffle plates supposed to increase the regeneration rate and classified as "Type A($L^*$=0.25, 80(L)$\times$300(W)$\times$50 (H) [mm])", "Type B($L^*$=0.5, 150(L)$\times$300(W)$\times$50 (H) [mm])", and "Type C($L^*$=0.75, 230(L)$\times$300(W)$\times$50(H) [mm])" were suggested and tested. They were placed between the vertical C-C layers in the tank. Solution temperature and concentration were used to evaluate the regeneration rate. As a result, the regeneration rate was better in "Type C".

• ETRI Journal
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• v.42 no.4
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• pp.575-584
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• 2020

Electromagnetic (EM) waves used to send signals under seawater are normally restricted to low frequencies (f) because of sudden exponential increases of attenuation (𝛼) at higher f. The mathematics of EM wave propagation in seawater demonstrate dependence on relative permeability (𝜇_r), relative permittivity (𝜀_r), conductivity (𝜎), and f of transmission. Estimation of 𝜀_r and 𝜎 based on the W. Ellison interpolation model was performed for averaged real-time data of temperature (T) and salinity (S) from 1955 to 2012 for all oceans with 41 088 latitude/longitude points and 101 depth points up to 5500 m. Estimation of parameters such as real and imaginary parts of 𝜀_r, 𝜀_r', 𝜀_r", 𝜎, loss tangent (tan 𝛿), propagation velocity (V_p), phase constant (𝛽), and α contributes to absorption loss (L_a) for seawater channels carried out by using normal distribution fit in the 3 GHz-40 GHz f range. We also estimated total path loss (L_PL) in seawater for given transmission power P_t and antenna (dipole) gain. MATLAB is the simulation tool used for analysis.

• Journal of the Korean Mathematical Society
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• v.50 no.2
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• pp.411-423
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• 2013

For any $p{\in}(1,2)$ and arbitrary $f{\in}L^p(\mathbb{R}^2)$ with compact support, it is proved that there exists a pair (L, $u$), with L second order uniformly elliptic operator and $u{\in}W_0^{2,p}(\mathbb{R}^2)$ such that $Lu=f$ a.e. in $\mathbb{R}^2$.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.12 no.5
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• pp.493-498
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• 2019

This study deals with the analysis of the technology association rules between CPC codes of the Internet of Things(IoT) patent, the core of the Fourth Industrial Revolution ICT-based technology. The association rules between CPC codes were extracted using R, an open source for data mining. To this end, we analyzed 369 of the 605 patents related to the Internet of Things filed with the Patent Office until July 2019, with a complex CPC code, up to the subclass-level. As a result of the technology association rules, CPC codes with high support were [H04W ${\rightarrow}$ H04L](18.2%), [H04L ${\rightarrow}$ H04W](18.2%), [G06Q ${\rightarrow}$ H04L](17.3%), [H04L ${\rightarrow}$ G06Q](17.3%), [H04W ${\rightarrow}$ G06Q](9.8%), [G06Q ${\rightarrow}$ H04W](9.8%), [G06F ${\rightarrow}$ H04L](7.9%), [H04L ${\rightarrow}$ G06F](7.9%), [G06F ${\rightarrow}$ G06Q](6.2%), [G06Q ${\rightarrow}$ G06F](6.2%). After analyzing the technology interconnection network, the core CPC codes related to technology association rules are G06Q and H04L. The results of this study can be used to predict future patent trends.

• Honam Mathematical Journal
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• v.27 no.1
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• pp.69-76
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• 2005

The aim of this work is to generalize $L_1$-approximation in order to apply them to a discrete approximation. In $L_1$-approximation, we use the norm given by $${\parallel}f{\parallel}_1={\int}{\mid}f{\mid}d{\mu}$$ where ${\mu}$ a non-atomic positive measure. In this paper, we go to the other extreme and consider measure ${\mu}$ which is purely atomic. In fact we shall assume that ${\mu}$ has exactly m atoms. For any ${\ell}$-tuple $b^1,\;{\cdots},\;b^{\ell}{\in}{\mathbb{R}}^m$, we defined the ${\ell}^m_1{w}$-norn, and consider $s^*{\in}S$ such that, for any $b^1,\;{\cdots},\;b^{\ell}{\in}{\mathbb{R}}^m$, $$\array{min&max\\{s{\in}S}&{1{\leq}i{\leq}{\ell}}}\;{\parallel}b^i-s{\parallel}_w$$, where S is a n-dimensional subspace of ${\mathbb{R}}^m$. The $s^*$ is called the Chebyshev center or a discrete simultaneous ${\ell}^m_1$-approximation from the finite dimensional subspace.

• Journal for History of Mathematics
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• v.12 no.1
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• pp.65-72
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• 1999

In this article, we give a historical referencing overview and compressed illuminating procedure of deriving the repersentors R$_y$(x) in Reproducing Kernel space W$^2_2$(R), being needed to find the solutions of integral equations, which construct the wavelets in L$^2$(1R).

• Korean Journal of Fisheries and Aquatic Sciences
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• v.22 no.5
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• pp.281-290
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• 1989

Growth of the Korean pomfret, Pampus echinogaster, captured in the East China Sea from January to December 1987, was estimated by annual rings on the vertebral centrum. The time of annual ring formation was approximately during September and October. Von Ber-talanffy growth equations derived from the mean back-calculated fork length(cm) at each age were as follows: for females, $L_{t}=29.17(1-e xp(-0.3213(t+0.7601)))$, for males, $L_t=28.21(1-e xp(-0.3169(t+0.8284)))$, and for sexes combined, $L_t=29.00(1-e xp(-0.3228(t+0.7361)))$, Seasonal growth equations derived from the mean observed fork length (cm) at age by month were as follows: for females, $L_t=29.2(1-e xp(-0.3458(t+0.8182)+(0.3458/2\pi)sin2\pi(t+0.027)))$, and for males, $L_t=28.2(1-e xp(-0.2789(t+1.5913)+(0.2789/2\pi)sin2\pi(t-0.1062)))$.

• Journal of the korean academy of Pediatric Dentistry
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• v.44 no.1
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• pp.28-37
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• 2017

Mineral trioxide aggregate have been used for many years as a pulp therapy material. The most widely used product, Proroot white $MTA^{(R)}$ has a major drawback that it causes tooth discoloration. This study assessed discoloration of crown when various MTA-based materials were placed in the coronal aspect of the root canal. Seventy-five single-rooted, unrestored premolar teeth were selected. The teeth were randomly assigned to four experimental groups, each of $Biodentine^{(R)}$, Proroot $wMTA^{(R)}$, $Endocem^{(R)}$, $RetroMTA^{(R)}$ and one negative control groups. Color measurements were utilized by the Commission International de I'Eclairage's L*a*b* system with spectrophotometer. The color was assessed eight times : initial, 1 day, 1 week, 2 weeks, 4 weeks, 8 weeks, 12 weeks, and 16 weeks after the placement. Statistical analysis was performed using the 2-way repeated analysis of variance and Bonferroni's method with p < 0.05. Proroot $wMTA^{(R)}$ induced significant decreases in $L^*$ values during experiment period. Tooth samples from the $Endocem^{(R)}$ group presented indistinct grayish color changes. The $Biodentine^{(R)}$ and $RetroMTA^{(R)}$ showed color stability. Consequently, while Proroot $wMTA^{(R)}$ and $Endocem^{(R)}$ that contain bismuth oxide as a radiopacifier showed tooth discoloration, displayed no sign of discoloration $Biodentine^{(R)}$ and $RetroMTA^{(R)}$ that contain zirconium oxide as a radiopacifier.

• 한국정보디스플레이학회:학술대회논문집
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• 2007.08a
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• pp.145-148
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• 2007

The authors report on the fabrication of thin film transistors (TFTs) that use amorphous indium-gallium-zinc oxide (a-IGZO) channel and have the channel length (L) and width (W) patterned by dry etching. To prevent the plasma damage of active channel, a 100-nm-thckness $SiO_{x}$ by PECVD was adopted as an etch-stopper structure. IGZO TFT (W/L=10/50${\mu}m$) fabricated on glass exhibited the high performance mobility of $35.8\;cm^2/Vs$, a subthreshold gate voltage swing of $0.59V/dec$, and $I_{on/off}$ of $4.9{\times}10^6$. In addition, 4.1” transparent QCIF active-matrix organic light-emitting diode display were successfully fabricated, which was driven by a-IGZO TFTs.