• 한국약용작물학회:학술대회논문집
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• 2008.05a
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• pp.132-133
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• 2008

• Bulletin of the Korean Mathematical Society
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• v.35 no.1
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• pp.127-140
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• 1998

In this paper, we discuss the characterizations and uniqueness of a one-sided best simultaneous approximation for a compact subset from a convex subset of a finite-dimensional subspace of a normed linear space $C_1(X)$. The motivation is furnished by the characterizations of the one-sided best simultaneous approximations for a finite subset ${f_1, \ldots, f_\ell}$ for any $\ell \in N$.

• Kyungpook Mathematical Journal
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• v.48 no.1
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• pp.123-132
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• 2008

In this paper, we investigate higher-order linear differential equations with entire coefficients of iterated order. We improve and extend the result of L. Z. Yang by using the estimates for the logarithmic derivative of a transcendental meromorphic function due to Gundersen and the extended Wiman-Valiron theory by Wang and Yi. We also consider the nonhomogeneous linear differential equations.

• 한국약용작물학회:학술대회논문집
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• 2012.05a
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• pp.131-132
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• 2012

• Proceedings of the Korea Institute of Convergence Signal Processing
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• 2000.08a
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• pp.129-132
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• 2000

We propose a new method to deal with the optimized auto-tuning for the PID controller which is used to the process -control in various fields. First of all, in this method, initial values of DC motor are determined by the Ziegler-Nichols method. Finally, after studying the parameters of PID controller by input vector of multiple regression analysis, when we give new K, L, T values to multiple regression model, the optimized parameters of PID controller is found by multiple regression analysis program.

• Journal of Korean Society of Environmental Engineers
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• v.31 no.2
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• pp.79-89
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• 2009

Naphthalene is a volatile, hydrophobic, and possibly carcinogenic compound that is known to have a severe detrimental effect to aquatic ecosystem. Our research examined the effects of various operating conditions (temperature, pH, initial concentration, and frequency and type of ultrasound) on the sonochemical degradation of naphthalene and OH radical production. The MDL (Method detection limit) determined by LC/FLD (1200 series, Agilient) using C-18 reversed column is measured up to 0.01 ppm. Naphthalene vapor produced from ultrasound irradiation was detected under 0.05 ppm. Comparison of naphthalene sonodegradion efficiency tested under open and closed reactor cover fell within less than 1% of difference. Increasing the reaction temperature from $15^{\circ}C$ to $40^{\circ}C$ resulted in reduction of naphthalene degradation efficiency ($15^{\circ}C$: 95% ${\rightarrow}$ $40^{\circ}C$: 85%), and altering pH from 12 to 3 increased the effect (pH 12: 84% ${\rightarrow}$pH 3: 95.6%). Pseudo first-order constants ($k_1$) of sonodegradation of naphthalene decreased as initial concentration of naphthalene increased (2.5 ppm: $27.3{\times}10^{-3}\;min^{-3}\;{\rightarrow}$ 10 ppm : $19.3{\times}10^{-3}\;min^{-3}$). Degradation efficiency of 2.5 ppm of naphthalene subjected to 28 kHz of ultrasonic irradiation was found to be 1.46 times as much as when exposed under 132 kHz (132 kHz: 56%, 28 kHz: 82.7%). Additionally, its $k_1$ constant was increased by 2.3 times (132 kHz: $2.4{\times}10^{-3}\;min^{-1}$, 28 kHz: $5.0{\times}10^{-3}\;min^{-1}$). $H_2O_2$ concentration measured 10 minutes after the exposure to 132 kHz of ultrasound, when compared with the measurement under frequency of 28 kHz, was 7.2 times as much. The concentration measured after 90 minutes, however, showed the difference of only 10%. (concentration of $H_2O_2$ under 28 kHz being 1.1 times greater than that under 132 kHz.) The $H_2O_2$ concentration resulting from 2.5 ppm naphthalene after 90 minutes of sonication at 24 kHz and 132 kHz were lower by 0.05 and 0.1 ppm, respectively, than the concentration measured from the irradiated M.Q. water (no naphthalene added.) Degradation efficiency of horn type (24 kHz) and bath type (28 kHz) ultrasound was found to be 87% and 82.7%, respectively, and $k_1$ was calculated into $22.8{\times}10^{-3}\;min^{-1}$ and $18.7{\times}10^{-3}\;min^{-1}$ respectively. Using the multi- frequency and mixed type of ultrasound system (28 kHz bath type + 24 kHz horn type) simultaneously resulted in combined efficiency of 88.1%, while $H_2O_2$ concentration increased 3.5 times (28 kHz + 24 kHz: 2.37 ppm, 24 kHz: 0.7 ppm.) Therefore, the multi-frequency and mixed type of ultrasound system procedure might be most effectively used for removing the substances that are easily oxidized by the OH radical.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.34 no.5
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• pp.465-472
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• 2001

The effects of water level reduction in rearing tank and fish transference during fish selection process on the stress response (hematological factors, cortisol, glucose, lactic acid and osmolality) of tank-reared olive flounder Paralichthys olivaceus of large (FL), small (FS) and Japanese croaker, Nibea japonica (JC) were examined in running seawater culture system. The water level of rearing unit was lowered from 33 cm to 8 cm in the course of 2 minutes in the water level reduction experiment. The fish were removed from rearing tank (12 ton) to 450 L tank in 30 seconds after capture in the fish transference experiment, In water level reduction, the hematocrit of FL was significantly increased from $14.6\%$ at beginning to $23.5\%$ after 10 hours, However, it decreased to the value of beginning after 46 hours. Plasma cortisol concentration of FL was the highest concentration (13.7 ng/mL) after 22 hours, but it decreased to 4.0 ng/mL at the end of experiment. Cortisol concentration of FS did not show any significant difference during the experiment. The cortisol concentration of JC were significantly higher at 4 hours (282.3 ng/mL) and 22 hours (350.5 ng/mL), Glucose concentration of JC was the highest (138.0 mg/dL) at 22 hours. Lactic acid concentration was not different between experimental groups. In the fish transference experiment, red blood cell of FL was increased from $1.9\times10^6\;cell/{\mu}\;L\;to\;4.2\times10^6\;cell/{\mu}L$ in 24 hours. Blood hemoglobin of JC were significantly elevated in 24 hours. At 1 hour after transference, plasma cortisol concentrations in both fish species were increased to 95.3 ng/mL in FL and 175.5 ng/mL in JC. Glucose concentration of JC was increased to 132.5 mg/dL at 1 hour, 129.5 mg/dL at 3 hours after transference.

• Environmental Analysis Health and Toxicology
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• v.24 no.4
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• pp.341-350
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• 2009

This study involves a relationship between butyltins concentrations and histopathological changes of the digestive gland in the equilateral venus, Gomphina veneriformis exposed to TBTCl of 0.4, 0.6 and 0.8 ${\mu}g/L$ for 36 weeks. In the sediment, total butyltin (${\sum}BT$) concentration was detected ND~7.54 (0.4 ${\mu}g/L$), ND~9.76 (0.6 ${\mu}g/L$), 1.22~13.13 ${\mu}g/L$ (0.8 ${\mu}g/L$), respectively. Especially, TBT level in 0.8 ${\mu}g/L$ group was the highest for 36 weeks. In the soft tissue, total butyltin (${\sum}BT$) concentration of the exposure group was 10.14~12.75 (control), 479.29~1,286.56 (0.4 ${\mu}g/L$), 563.32~2,154.82 (0.6 ${\mu}g/L$) and 1,317.70~2,132.60 ${\mu}g/L$ (0.8 ${\mu}g/L$), respectively. Ratio of TBT to ${\sum}BT$ of the tissue of 0.8 ${\mu}g/L$ kept the lowest level for 36 weeks. The ${\sum}BT$ concentrations of sediment were correlated with ${\sum}BT$ concentrations in the tissue. In the exposure groups, necrosis and atrophy of columnar epithelial cell and collapse of epithelial layer in the digestive tubule. And there was a reduction in stain affinity of basophilic cell. Such histological degenerations was more severe in digestive tubule of 0.8 ${\mu}g/L$ group.

• KSBB Journal
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• v.24 no.6
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• pp.541-548
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• 2009

For investigation of anti-angiogenesis mechanism of Anthrisci radix, Psoraleae semen, Siegesbeckiae herba and Corni fructus, anti-cell adhesion experiment was performed. The adhesion of U937 cells to IL-$1\beta$-stimulated HUVECs was completely suppressed by 276% at 0.2 mg/L of Anthrisci radix, 220% at 5 mg/L of Psoraleae semen, 158% at 10 mg/L of Siegesbeckiae herba and 132% at 20 mg/L of Corni fructus, respectively. And the adhesion of PMA-chemical stimulated U937 cells to HUVECs, it was inhibited 139% at 0.2 mg/L of Anthrisci radix, 442% at 5 mg/L of Psoraleae semen, 720% at 10 mg/L of Siegesbeckiae herba and 664% at 20 mg/L of Corni fructus. Also, the adhesion of chemical stimulated U937 cells to IL-$1\beta$/chemical stimullated HUVECs, it was inhibited by 286% at 0.2 mg/L of Anthrisci radix, 146% at 5 mg/L of Psoraleae semen, 436% at 10 mg/L of Siegesbeckiae herba and 297% at 20 mg/L of Corni fructus, respectively. It would be a useful substance for anti-cell adhesion based on anti-angiogenesis for anti-obesity and anti-cancer.

• Journal of Microbiology
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• v.38 no.3
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• pp.132-136
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• 2000

We recently identified Leuconostoc gelidum, a typical psychrophile, as a microbial component from kimchi that has been laboratory-prepared and fermented at 20$^{\circ}C$ . However, it has been shown that the growth of leuconostocs in food products is highly influenced by fermenting temperature. To determine the distribution of L. gelidum species in kimchi fermented at a lower temperature , 8$^{\circ}C$, we characterized a total of 64 dextran-forming strains isolated from kimchi using a polyphsic method including 16S rDNA sequencing and DNA-DNA gybridization. We found that 80% of the isolated were L. gelidum, which has been found mainly at chill-stored meat products. We also found that L. gelidum could be a dominant Leuconostoc species in so-called KimJang Kimchi, which is traditionally prepared at lat fall to be preserved during winter in Korea. These results suggest that L. gelidum can be a predominant species in kimchi especially when fermented at low temperature.