• Journal of Korea Water Resources Association
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• v.38 no.11
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• pp.955-962
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• 2005

Even though the runoff volume is very sensitive to the antecedent soil moisture condition (AMC), the general rainfall-runoff analysis in Korea has accepted, without careful consideration of its applicability, the AMC classification of the Soil Conservation Service (SCS, 1972). In this study, by following the development procedure of SCS Curve Number (CN), the rainfall-runoff characteristics of the Jangpyung subbasin of the Pyungchang River Basin were analyzed to estimate the CN and evaluate the AMC classification of currently being used. As results, CN(I), CN(II), and CN(III) were estimated to be 72.1, 79.3, and 76.7, respectively. Among them CN(II) was found to be similar to the other reports but the other two were totally different from those of theoretically estimated. However, it is difficult to evaluate the AMC with CN, rather the frequency of each AMC could be a better indicator for its validity. This study developed the histogram of AMC and compared the frequency of each AMC. hs results we found that the criterion for AMC-III should be increased, Hut that for AMC-I decreased.

• Economic and Environmental Geology
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• v.42 no.3
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• pp.177-193
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• 2009

The Samgwang deposit consists of eight massive mesothermal quartz veins that filled NE and NW-striking fractures along fault zones in Precambrian granitic gneiss of the Gyeonggi massif. The mineralogy and paragenesis of the veins allow two separate discrete mineralization episodes(stage I=quartz and calcite stage, stage II-calcite stage) to be recognized, temporally separated by a major faulting event. The ore minerals are contained within quartz and calcite associated with fracturing and healing of veins that occurred during both mineralization episodes. The hydrothermal alteration of stage I is sericitization, chloritization, carbonitization, pyritization, silicification and argillization. Sericitic zone occurs near and at quartz vein and include mainly sericite, quartz, and minor illite, carbonates and chlorite. Chloritic zone occurs far from quartz vein and is composed of mainly chlorite, quartz and minor sericite, carbonates and epidote. Fe/(Fe+Mg) ratios of sericite and chlorite range 0.45 to 0.50(0.48$\pm$0.02) and 0.74 to 0.81(0.77$\pm$0.03), and belong to muscovite-petzite series and brunsvigite, respectiveIy. Calculated $Al_{IV}$-FE/(FE+Mg) diagrams of sericite and chlorite suggest that this can be a reliable indicator of alteration temperature in Au-Ag deposits. Calculated activities of chlorite end member are $a3(Fe_5Al_2Si_3O_{10}(OH)_6$=0.0275${\sim}$0.0413, $a2(Mg_5Al_2Si_3O_{10}(OH)_6$=1.18E-10${\sim}$7.79E-7, $a1(Mg_6Si_4O_{10}(OH)_6$=4.92E-10${\sim}$9.29E-7. It suggest that chlorite from the Samgwang deposit is iron-rich chlorite formed due to decreasing temperature from high temperature(T>450$^{\circ}C$). Calculated ${\alpha}Na^+$, ${\alpha}K^+$, ${\alpha}Ca^{2+}$, ${\alpha}Mg^{2+}$ and pH values during wallrock alteration are 0.0476($400^{\circ}C$), 0.0863($350^{\circ}C$), 0.0154($400^{\circ}C$), 0.0231($350^{\circ}C$), 2.42E-11($400^{\circ}C$), 7.07E-10($350^{\circ}C$), 1.59E-12($400^{\circ}C$), 1.77E-11($350^{\circ}C$), 5.4${\sim}$6.4($400^{\circ}C$), 5.3${\sim}$5.7($350^{\circ}C$)respectively. Gain elements(enrichment elements) during wallrock alteration are $TiO_2$, $Fe_2O_3(T)$,CaO, MnO, MgO, As, Ag, Cu, Zn, Ni, Co, W, V, Br, Cs, Rb, Sc, Bi, Nb, Sb, Se, Sn and Lu. Elements(Ag, As, Zn, Sc, Sb, Rb, S, $CO_2$) represents a potential tools for exploration in mesothermal and epithermal gold-silver deposits.

• Journal of Animal Science and Technology
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• v.44 no.3
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• pp.289-296
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• 2002

A broiler experiment was conducted to investigate the effect of supplementing yeast culture (Saccharomyces cerevisiae, Pichia pastoris) on the growth performance, small intestinal microflora and immune response in broiler chickens. One thousand hatched broiler chickens(Ross$^{(R)}$) were assigned to 6 treatments: control (basal diet), CTC; chlorotetracycline 100ppm, YC-SC; yeast culture(Saccharomyces cerevisiae) 0.3%, YC-PP; yeast culture(Pichia pastoris) 0.3%, RPPC-0.1; refined Pichia pastoris culture 0.1%, RPPC-0.3; refined Pichia pastoris culture 0.3%. There were no significant differences in growth, feed intake, feed efficiency and mortality among the treatments. However, chickens fed diets with yeast cultures showed numerically higher weight gain than those fed the control diets. Supplementation of yeast cultures and CTC improved feed efficiency and decreased mortality compared to control. Nutrient digestibilities were not affected by the dietary treatments. Total number of Lactobacilli in small intestine was higher while that of Cl. perfringens was lower with yeast culture treatments than control. Small intestine E. coli population of RPPC-0.3 treatment was significantly lower than that of the control. The serum IgG concentration tended to be higher in broilers fed yeast cultures than those fed the control and CTC diet. In conclusion, the supplementation of yeast culture products showed, although not significant but, numerical advantages in productivity and profile of microbial flora and serum IgG compared to the control and CTC supplementation.

• Journal of the Institute of Electronics Engineers of Korea SC
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• v.45 no.1
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• pp.1-8
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• 2008

A two-wheel balancing vehicle, which helps people moving freely and fast, and is applied from inverted pendulum system, has been widely researched and developed, and some products are came into a market in actuality. Until now, the two-wheel balancing vehicles developed have chosen the general PID control method. In this paper, we propose a new control method to improve a control capacity for a two-wheeled balancing vehicle for human transportation. The proposed method is the fuzzy PD+I control that is one of the improved PID control, and it contains a 2input-1output fuzzy system. This fuzzy system processes signals from proportional and derivative controller, and the fuzzy output signal generates the final output by summing up integral signal. The non-linearity of the fuzzy system makes an optimal output control signal by changing weight of the proportional signal and the derivative signal in process of time. We have simulated the fuzzy PD+I control system and experimented by implementing the two-wheel balancing mobile robot to verify the advantages of the proposed fuzzy PD+I control method in comparison with general PID control. As the results of simulation and experimentation, the proposed fuzzy PD+I control method has better control performance than general PID in this system and improves it.

• Journal of the Institute of Electronics Engineers of Korea SC
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• v.44 no.1
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• pp.85-93
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• 2007

This paper presents new LVDS I/O circuits with a high noise margin for use in highly parallel I/O environments. The proposed LVDS I/O includes transmitter and receiver parts. The transmitter circuits consist of a differential phase splitter and a output stage with common mode feedback(CMFB). The differential phase splitter generates a pair of differential signals which have a balanced duty cycle and $180^{\circ}$ phase difference over a wide supply voltage variation due to SSO(simultaneous switching output) noises. The CMFB output stage produces the required constant output current and maintains the required VCM(common mode voltage) within ${\pm}$0.1V tolerance without external circuits in a SSO environment. The proposed receiver circuits in this paper utilizes a three-stage structure(single-ended differential amp., common source amp., output stage) to accurately receive high-speed signals. The receiver part employs a very wide common mode input range differential amplifier(VCDA). As a result, the receiver improves the immunities for the common mode noise and for the supply voltage difference, represented by Vgdp, between the transmitter and receiver sides. Also, the receiver produces a rail-to-rail, full swing output voltage with a balanced duty cycle(50% ${\pm}$ 3%) without external circuits in a SSO environment, which enables correct data recovery. The proposed LVDS I/O circuits have been designed and simulated with 0.18um TSMC library using H-SPICE.

• Economic and Environmental Geology
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• v.38 no.2 s.171
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• pp.113-127
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• 2005

Cretaceous intrusive and extrusive rocks are widely distributed in the southwestern part of the Korean peninsula, possibly the result of intensive magmatism which occurred in response to subduction of the western proto-Pacific plate beneath the north-eastern part of the Eurasian plate. Geochemical and petrological study on the Cretaceous granitic rocks were carried out in order to constrain the petrogenesis of the granitic magma and to establish the paleotectonic environment of the area. Whole rock chemical data of the granitic rocks from the study area indicate that the all the rocks have characteristics of calc-alkaline series in the subalkaline field. The overall geochemical features show systematic variations in each granitic body, but the source materials of each granitic body are thought to have been different in their chemical composition. Higher values of $Fe_2O_3/FeO$ of the granitic rocks in the western area suggest that the granitoids had been solidified under highly oxidizing environment. The granitic bodies in the eastern area also show higher contents of Li, Ni, Co, Sr, Cr, Sc and lower Rb and Nb compared to the those of the western area. Chondrite normalized REE patterns show generally enriched LREE and strong negative Eu anomalies in the western wet while slight to flat Eu anomalies in the east-ern area. The REE and $(La/Lu)_{CN}$ of the granites are $60{\~}499ppm$ and $8.9{\~}66$ correspond to the range of the continental margin granite. On the ANK vs. ACNK and tectonic discrimination diagrams, parental magma type of the granites corresponds to I-type, VAG and syn-collision granite. Interpretations of the chemical characteristics of the granitic rocks favor their emplacement in a compressional tectonic regime at continental margin during the subduction of proto-Pacific plate.

• Journal of the Korean Society of Food Science and Nutrition
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• v.33 no.10
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• pp.1594-1600
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• 2004

Effects of mistletoe (Viscum album) extract and pueraria (Pueraria radix) extract on cellular NF-$textsc{k}$B activity were evaluated in human malignant keratinocytes (SCC-13) to elucidate the possible correlation of NF-$textsc{k}$B with antioxidant activity. The antioxidant activities of these natural extracts were examined in four different evaluation methods, i.e., lipid peroxidation value (POV) evaluation test, I,l-diphenyl-2-picrylhydrazyl radical (DPPH), nitric oxide (NO) scavenging test, and reducing power assay. Pueraria extract (0.5 mg) and mistletoe extract (5 mg) downregulated the cellular NF-$textsc{k}$B activation up to 35% and 10% compared to the control, respectively, although their effects were lower than the known NF-$textsc{k}$B downregulator, vitamin C (8.8 mg, 53%) in a cell-based NF-$textsc{k}$B activity assay system. In the POV test, relative antioxidant activities of mistletoe extract (86%) and pueraria extract (75%) were significantly higher than the known antioxidant, vitamin C (48%) at the same concentration (10 mg) and the degree of activity increased in a dose-dependent manner. Pueraria extract showed more potential radical scavenging activities than those of mistletoe extract evaluated in both DPPH and NO test. Especially, the NO radical scavenging activity of pueraria extract ($SC_{50}$/, 88 $\mu$g) was comparable to that of vitamin C ($SC_{50}$/, 77 $\mu$g). Even pueraria extract possessed a much less reducing power compared to vitamin C, it also revealed higher reducing power than that of mistletoe extract. These results indicate that mistletoe extract and pueraria extract may serve as an useful natural antioxidant agents, and led to suggest the hypothesis that compounds having an antioxidant activity, i.e., radical scavenging activity or reducing power may be correlated with the downregulation of NF-$textsc{k}$B activation in human keratinocytes.

• Current Photovoltaic Research
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• v.7 no.4
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• pp.97-102
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• 2019

Bifacial and semitransparent hydrogenated amorphous silicon (a-Si:H) thin-film solar cells in p-i-n configuration were prepared with front and rear transparent conducting oxide (TCO) electrodes using plasma-enhanced chemical vapor deposition method. Fluorine-doped tin oxide and tin-doped indium oxide films were used as front and rear TCO contacts, respectively. Film thickness of intrinsic a-Si:H absorber layers were controlled from 150 nm to 450 nm by changing deposition time. The dependence of performance characteristics of solar cells on the front and rear illumination direction were investigated. For front illumination, gradual increase in the short-circuit current density (J_SC) from 10.59 mA/㎠ to 14.19 mA/㎠ was obtained, whereas slight decreases from 0.83 V to 0.81 V for the open-circuit voltage (V_OC) and from 68.43% to 65.75% for fill factor (FF) were observed. The average optical transmittance in the wavelength region of 380 ~ 780 nm of the solar cells decreased gradually from 22.76% to 15.67% as the absorber thickness was changed from 150 nm to 450 nm. In case of the solar cells under rear illumination condition, the J_SC increased from 10.81 to 12.64 mA/㎠ and the FF deceased from 66.63% to 61.85%, while the V_OC values were maintained at 0.80 V with increasing the absorber thickness from 150 nm to 450 nm. By optimizing the deposition parameters, a high-quality bifacial and semitransparent a-Si:H solar cell with 350 nm-thick i-a-Si:H absorber layer exhibited the conversion efficiencies of 7.69% for front illumination and 6.40% for rear illumination, and average visible optical transmittance of 17.20%.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.43 no.1
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• pp.69-78
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• 2017

Hwangryunhaedoktang (HHT) has been traditionally used as a preventive and therapeutic medicine to treat enervation and diverse chronic diseases. This study was designed to compare the antioxidant, anti-wrinkle and whitening effects of HHT extract and its fermented extract by Leuconostoc mesenteroides (FHHT). FHHT was prepared by inoculation of L. mesenteroides after the extraction procedure with 70% ethanol. HHT and FHHT was investigated via high-performance liquid chromatography (HPLC). Simultaneous qualitative analysis of two bioacitive components, berberine and palmatine. was achieved by comparing their retention times ($t_R$) and UV spectra with those of the standard components. Cell viability test results indicated that both HHT and FHHT were non-toxic. In DPPH radical scavenging ability, $SC_{50}$ values of the FHHT was $68.85{\mu}g/mL$, which is more effective than HHT. Moreover, FHHT showed higher expression in production of procollagen type I than HHT. In nontoxic concentration range, FHHT showed strong melanin production inhibitory effect in ${\alpha}-melanocyte$ stimulating hormone (${\alpha}-MSH$)-stimulated B16F10 cell ($IC_{50}=9.82{\mu}g/mL$). These results suggested that fermented extracts of hwangryunhaedoktang had considerable potential as a cosmetics ingredient with an antioxidant and anti-wrinkle and whitening effects.

• Bulletin of the Korean Chemical Society
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• v.32 no.8
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• pp.2743-2750
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• 2011

Lanthanide(III)-cored complex as a wavelength conversion material has been successfully designed and synthesized for highly efficient dye-sensitized solar cells, for the first time, since light with a short wavelength has not been effectively used for generating electric power owing to the limited absorption of these DSSCs in the UV region. A black dye (BD) was chosen and used as a sensitizer, because BD has a relatively weak light absorption at shorter wavelengths. The overall conversion efficiency of the BD/WCM device was remarkably increased, even with the relatively small amount of WCM added to the device. The enhancement in $V_{oc}$ by WCM, like DCA, could be correlated with the suppression of electron recombination between the injected electrons and $I_3{^-}$ ions. Furthermore, the short-circuit current density was significantly increased by WCM with a strong UV light-harvesting effect. The energy transfer from the Eu(III)-cored complex to the $TiO_2$ film occurred via the dye, so the number of electrons injected into the $TiO_2$ surface increased, i.e., the short-circuit current density was increased. As a result, BD/WCM-sensitized solar cells exhibit superior device performance with the enhanced conversion efficiency by a factor of 1.22 under AM 1.5 sunlight: The photovoltaic performance of the BD/WCM-based DSSC exhibited remarkably high values, $J_{sc}$ of 17.72 mA/$cm^2$, $V_{oc}$ of 720 mV, and a conversion efficiency of 9.28% at 100 mW $cm^{-2}$, compared to a standard DSSC with $J_{sc}$ of 15.53 mA/$cm^2$, $V_{oc}$ of 689 mV, and a conversion efficiency of 7.58% at 100 mW $cm^{-2}$. Therefore, the Eu(III)-cored complex is a promising candidate as a new wavelength conversion coadsorbent for highly efficient dye-sensitized solar cells to improve UV light harvesting through energy transfer processes. The abstract should be a single paragraph which summaries the content of the article.