• Tuberculosis and Respiratory Diseases
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• v.53 no.4
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• pp.420-430
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• 2002

Background : Excessive extracellular matrix (ECM) deposition by airway inflammation is presumed to play an important role in the pathogenesis of worsening airflow obstruction (Ed- acceptable three-word noun) seen during acute exacerbations of chronic bronchitis. Although many proteases can cleave ECM molecules, matrix metalloproteinases (MMPs) and their inhibitors are likely to be the physiologically relevant mediators of ECM degradation. Objectives ; The purpose of this study was to demonstrate that antibiotic treatment can change airway MMPs and TIMP-1 concentrations/levels by controlling airway inflammation in acute exacerbation of chronic bronchitis. Methods : We studied 40 patients, all of whom had an acute exacerbation of chronic bronchitis. The patients were treated with two different antibiotics, moxifloxacin and clarithromycin, in a double-blind manner for 7 days. Sputum samples were induced and collected before and after antibiotic therapy. We measured the sputum concentration of MMP-1,-9, TIMP-1, IL-8 and secretory leukocyte proteinase inhibitor (SLPI) in sputum supernatants by ELISA method. Results : There was no difference after antibiotic treatment in the sputum concentrations of MMP-1,-9, TIMP-1, IL-8 and SLPI between the patients treated with moxifloxacin and those treated with clarithromycin. But the sputum concentrations of TIMP-1, and SLPI, and the TIMP-1/MMP-1 ratio were significantly reduced by the antibiotic therapy. There were significant positive correlations between sputum TIMP-1 levels and IL-8 levels (p<0.01, r=0.751), and between the sputum TIMP-1/MMP-1 ratio and IL-8 levels (p<0.01, r=0.752). The sputum SLPI levels were significantly elevated by antibiotic treatment and were negatively correlated with sputum TIMP-1 levels (p<0.01, r=-0.496) and TIMP-1/MMP-1 levels (p<0.01, r=-0.456). Conclusion : The study shows that the worsening of airway inflammation in acute exacerbation of chronic bronchitis is associated with an imbalance between the concentrations/levels of TIMP-1 and MMPs. Antibiotic treatment can prevent progression of airway narrowing in acute exacerbation of chronic bronchitis by modulation of the protease and anti-protease imbalance.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.6 no.2
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• pp.301-312
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• 1996

This study was performed to search a optimal analyzing method of cadmium in whole-blood. Cadmium was determined by graphite furnace atomic absorption spectrometry(GFAAS). We investigated the effect of ashing temperature on the absorbance of cadmium in a simple dilution(ten-fold) method with triton X-100 and matrix modifier methods treated with $NH_4H_2PO_4$(1 and 3%) and $Pd(NO_3)_2$(0.00l and 0.005%) as matrix modifier. We also compared the reported reference values of standard blood with values resulted from optimal analyzing conditions of this study. In case of a simple dilution method, when ashing temperature was set at $450^{\circ}C$, the absorbance of sample and background were $0.334{\pm}0.012$ and $1.382{\pm}0.245$, respectively. Background level was higher than the value(0.8) that can be corrected by $D_2$ background correction method. As ashing temperature was rised to $500^{\circ}C$, the absorbance of sample and background were $0.178{\pm}0.008$ and $0.711{\pm}0.223$ respectively. The higher ashing temperature($450^{\circ}C-650^{\circ}C$) was, the lower the absorbance of sample was. In case of a matrix modifier method with $NH_4H_2PO_4$(1 and 3%), when ashing temperature was rised from $500^{\circ}C$ to $650^{\circ}C$, the absorbance of sample slightly changed. The absorbances of sample at $600^{\circ}C$ were $0.230{\pm}0.017$ and $0.137{\pm}0.012$, respectively. These values were larger than that of simple dilution method. But the absorbance of background was higher than the level that can be corrected by $D_2$ method. In case of a matrix modifier method with $Pd(NO_3)_2$(0.001 and 0.005%), the absorbance of sample and background were higher than those of other methods and were stable and reproducible. When ashing temperature was over $550^{\circ}C$, the absorbance of sample was significantly decreased. In case of 0.005% $Pd(NO_3)_2$ carbon residue remained in graphite tube affected the absorbance of sample and background. From these results, We propose that in case of a simple dilution(ten-fold) method with triton X-100 ashing temperature must be maintained below $400^{\circ}C$. In order to diminish the absorbance of background, the alternative method is attenuation of injection volume or multiplication of dilution ratio. We recommend $Pd(NO_3)_2$ than $NH_4H_2PO_4$ as a matrix modifier. In case of a matrix modifier method with $Pd(NO_3)_2$ ashing temperature might be maintained below $550^{\circ}C$.

• Analytical Science and Technology
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• v.5 no.4
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• pp.349-358
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• 1992

The direct determination of lead in the whole-blood by graphite furnace atomic absorption spectrometric analysis was carried out by using the sample which was diluted five-fold with 1% Triton X-100. Matrix modification was tried to remove the interferences of blood matrix and also to get the optimum analytical condition. Good agreement with certificated values in reference materials(bovine blood) supplied by comparison program in Japan was obstained when 1% $(NH_4)_2HPO_4$ as matrix modifier and ashing temperature, $700^{\circ}C$ were used or 1% $(NH_4)_2HPO_4$ and 0.1% $PdCl_2$ as matrix modifier and ashed at $700^{\circ}C$. Standard deviations were appeared as 2.2~6.3% for 1% $(NH_4)_2HPO_4$ and 3.1~9.1% for 1% $(NH_4)_2HPO_4$ and 0.1% $PdCl_2$ in the range of $31{\sim}624{\mu}gPb/l$.

• The Korean Journal of Applied Statistics
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• v.16 no.1
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• pp.71-85
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• 2003

In the economic design of the process control procedure, where quality is measured at certain time intervals, its properties are difficult to derive due to the discreteness of the measurement intervals. In this paper a Markov chain representation of the process monitoring procedure is developed and used to derive its properties when the process follows an ARIMA(0,1,1) model, which is designed to describe the effect of the noise and the special cause in the process cycle. The properties of the Markov chain depend on the transition matrix, which is determined by the control procedure and the process distribution. The derived representation of the Markov chain can be adapted to most different types of control procedures and different kinds of process distributions by obtaining the corresponding transition matrix.

• Communications of the Korean Mathematical Society
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• v.14 no.2
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• pp.311-318
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• 1999

Let A be an n$\times$n (0,1) matrix. Let f(A) denote the smallest nonnegative integer k such that per A[$\alpha$｜$\beta$]>0 and A($\alpha$｜$\beta$) is permutation equivalent to a lower triangular matrix for some $\alpha$, $\beta$$\in$Q\ulcorner,\ulcorner. In this case f(A) is called the feedback number of A. In this paper, feedback numbers of some maximal convertible (0,1) matrices are studied.

• Journal of the Korean Ceramic Society
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• v.34 no.5
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• pp.500-504
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• 1997

Perovskite Pb0.7Ba0.3Zn1/3Nb2/3O3 substituted with 0.3 mole fraction for Pb-site in PbZn1/3Nb2/3O3 relaxor and pyrochlore Pb1.83Ba0.29Zn1.71Nb2/3O6.39 were mixed and dielectric characteristics of this composites were investigated. Percolation limit of perovskite phase, which was determined by microstructural observation in the composite as an isolation of perovskite phase from pyrochlore matrix, was 28.9-47.5 vol%. Ferroelectric phase transition below percolation limit depends on a parameter which affects the propagation of lattice vibration between isolated perovskite phase and pyrochlore matrix. Therefore, it is believed that ferroelectric lattice vibration of isolated perovskite phase could be transfered to pyrochlore matrix when the oxygen octahedra are linked in 3-dimension and highly polarizable Pb2+ ions are contained in both phases.

• Journal of international Conference on Electrical Machines and Systems
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• v.2 no.1
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• pp.77-82
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• 2013

By using simulation, compensating characteristics of a voltage sag compensator utilizing single-phase matrix converter is examined. System configuration is described and mathematical model of single-phase matrix converter is derived by using the state space averaging method. In addition, the single-phase matrix converter is stabilized by phase-lead compensation. Finally, compensating characteristics of the compensator is investigated for 500 W R-L load and it is demonstrated that the compensator can operate correctly for loads for the range of power factor 0.6 (lagging) - 0.8 (leading) and for up to 50% voltage sag.

• Communications of the Korean Mathematical Society
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• v.12 no.4
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• pp.841-849
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• 1997

A square matrix A with $per A \neq 0$ is called convertible if there exists a {1, -1} matrix H such that $per A = det(H \circ A)$ where $H \circ A$ denote the Hadamard product of H and A. In this paper, ranks of convertible {0, 1} matrices are investigated and the existence of maximal convertible matrices with its rank r for each integer r with $\left\lceil \frac{n}{2} \right\rceil \leq r \leq n$ is proved.

• Bulletin of the Korean Mathematical Society
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• v.51 no.3
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• pp.739-763
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• 2014

In this paper, the nonlinear matrix equation $$X+\sum_{i=1}^{m}A_i^*X^{-q}A_i=Q(0<q{\leq}1)$$ is investigated. Some necessary conditions and sufficient conditions for the existence of positive definite solutions for the matrix equation are derived. Two iterative methods for the maximal positive definite solution are proposed. A perturbation estimate and an explicit expression for the condition number of the maximal positive definite solution are obtained. The theoretical results are illustrated by numerical examples.

• Journal of the Korean Statistical Society
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• v.22 no.2
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• pp.249-258
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• 1993

It is well known that design matrix X for any factorial design can be represented by a product $X = TX_o$ where T is replication matrix and $X_o$ is the corresponding balanced design matrix. Since $X_o$ consists of regular arrangement of 0's and 1's, we can easily find the spectral decomposition of $X_o',X_o$. Also using this we propose an efficient algorithm for computing the orthogonal projection matrix for a balanced factorial design.