• Journal of the Computational Structural Engineering Institute of Korea
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• v.31 no.2
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• pp.115-120
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• 2018

This paper introduces a magnetic hysteresis monitoring result to apply an EM sensing technique for estimating tensile force of PSC girder to various class of PS tendon. The tensile force of PS tendon is a very important factor in the performance evaluation of PSC bridges. However, in this time, the tensile force was just measured only during construction and it does not monitored after construction. To measure the tensile force of PS tendons, the EM sensing based NDT method was developed but the proposed method cannot be applied to various class of PS tendons. Thus this study performed the magnetic hysteresis measurement according to the tensile force for class B, C and D PS tendons through experimental study. The specific tensile forces(50, 100, 150, 180kN) were induced to the each specimens and the magnetic hysteresis curve was measured at each point. The permeability of specimens were gradually decreased according to increase of tensile force. Especially, the slopes of permeability variation of class B and C were similar while that of class D was different.

• Radiation Oncology Journal
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• v.36 no.2
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• pp.139-146
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• 2018

Purpose: IBTR! 2.0 nomogram is web-based nomogram that predicts ipsilateral breast tumor recurrence (IBTR). We aimed to validate the IBTR! 2.0 using an external data set. Materials and Methods: The cohort consisted of 2,206 patients, who received breast conserving surgery and radiation therapy from 1992 to 2012 at our institution, where wide surgical excision is been routinely performed. Discrimination and calibration were used for assessing model performance. Patients with predicted 10-year IBTR risk based on an IBTR! 2.0 nomogram score of <3%, 3%-5%, 5%-10%, and >10% were assigned to groups 1, 2, 3, and 4, respectively. We also plotted calibration values to observe the actual IBTR rate against the nomogram-derived 10-year IBTR probabilities. Results: The median follow-up period was 73 months (range, 6 to 277 months). The area under the receiver operating characteristic curve was 0.607, showing poor accordance between the estimated and observed recurrence rate. Calibration plot confirmed that the IBTR! 2.0 nomogram predicted the 10-year IBTR risk higher than the observed IBTR rates in all groups. High discrepancies between nomogram IBTR predictions and observed IBTR rates were observed in overall risk groups. Compared with the original development dataset, our patients had fewer high grade tumors, less margin positivity, and less lymphovascular invasion, and more use of modern systemic therapies. Conclusions: IBTR! 2.0 nomogram seems to have the moderate discriminative ability with a tendency to over-estimating risk rate. Continued efforts are needed to ensure external applicability of published nomograms by validating the program using an external patient population.

• KEPCO Journal on Electric Power and Energy
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• v.6 no.2
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• pp.173-179
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• 2020

Electric vehicles (EVs) using lithium secondary batteries (LIBs) with excellent power and long-term cycle performance are gaining interest as the successors of internal combustion engine (ICE) vehicles. However, there are few systematic researches for fast charging to satisfy customers' needs. In this study, we compare the degradation of LIB where its composition is LiNi_0.5Co_0.2Mn_0.3/Graphite with the constant current and constant power-charging method. The charging speed was set to 1C, 2C, 3C and 4C in the constant current mode and the value of constant power was calculated based on the energy at each charging speed. Therefore, by analyzing the battery degradation based on the same charging energy but different charging method; CP charging method can slow down the battery degradation at a high rate of 3C through the voltage curve, capacity retention and DC-IR. However, when the charging rate was increased by 4C or more, the deviation between the LIBs dominated the degradation than the charging method.

• Journal of Pharmaceutical Investigation
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• v.34 no.3
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• pp.209-214
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• 2004

A bioequivalence study of $Roxithrin^{TM}$ tablet (Kukje Pharma. Ind. Co., Ltd.) to $Rulid^{TM}$ tablet (Han Dok Pharma. Ind. Co., Ltd.) was conducted according to the guidelines of Korea Food and Drug Administration (KFDA). Twenty four healthy male Korean volunteers received each medicine at the roxithromycin dose of 300 mg in a $2{\times}2$ crossover study. There was a one-week wash-out period between the doses. Plasma concentrations of roxithromycin were monitored by a high-performance liquid chromatography for over a period of 36 hours after drug administration. $AUC_t$ (the area under the plasma concentration-time curve from time zero to 36 hr) was calculated by the linear trapezoidal rule method. $C_{max}$ (maximum plasma drug concentration) and $T_{max}$ (time to reach $C_{max}$) were compiled from the plasma concentration-time data. Analysis of variance was carried out using logarithmically transformed $AUC_t$ and $C_{max}$. No significant sequence effect was found for all of the bioavailability parameters indicating that the cross-over design was properly performed. The 90% confidence intervals of the $AUC_t$ ratio and the $C_{max}$ ratio for $Roxithrin^{TM}/Rulid^{TM}$ were 1.00 - 1.13 and 0.98 - 1.10, respectively. These values were within the acceptable bioequivalence intervals of 0.80 - 1.25. Thus, our study demonstrated the bioequivalence of $Roxithrin^{TM}$ and $Rulid^{TM}$ with respect to the rate and extent of absorption.

• Journal of Applied Biological Chemistry
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• v.59 no.4
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• pp.323-330
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• 2016

Pinellia ternata Breitenbach, the natural medicinal plant of the Araceae family, is a perennial plant originated from the East Asia, but also widely distributed in Europe and North America. Its tuber is used as traditional medicine for treatment of various diseases such as vomiting, inflammation, and traumatic injury. Pharmacological studies revealed that P. ternata possesses anticonvulsant, anti-tumor, insecticidal, and cytotoxic activities. Despite being well-known as the useful medicinal plant, there is no reliable, standardized method for origin discrimination. Ultra performance liquid chromatography-photodiode array detector and quadrupole time of flight-mass spectrometry based metabolite-profiling was applied to explore significant metabolite for origin discrimination between Korean and Chinese P. ternata. One compound was isolated from Korean P. ternata using repeated ODS column chromatography by bioactivity guided fractionation, and determined as [6]-gingerol according to the results of spectroscopic data including nuclear magnetic resonance and MS. This compound was selected as cosmeceutical biomarker by fingerprints, and it was associated to melanin inhibitory effect determining its origin authenticity. Furthermore, the calibration curve of biomarker was prepared using validated method for the comparison of content between Korean and Chinese P. ternata. This is the report to address the selection and successful validation of the discriminant metabolite for confirmation of Korean P. ternata.

• Journal of the Korea institute for structural maintenance and inspection
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• v.17 no.2
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• pp.10-20
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• 2013

To evaluate the safety of a beam structure, strains are measured as an indicator of structural states. However, unless strain sensors are installed exactly on where maximum or other representative strains occur, the techniques by which rational assessment through measured strains is accomplished are required. Thus, this study suggests a process to estimate strain distribution on the steel beam from discrete strains measured by sensors. In the presented technique, the targeted beam is regarded to be subjected to unknown loads so that applicability is enhanced. Final strain distribution is given as form of a function after regression analysis. To verify the performance of estimation, a bending test for steel beam on which distributed and concentrated loads simultaneously act is conducted. From the comparison between estimated and directly measured strains in the test, the curve of strain distribution and the strain at arbitrary location could be predicted within maximum relative error 3.32% and maximum absolute error of $2.32{\mu}{\varepsilon}$, respectively. Thus reliable and practical monitoring is expected to apply effectively for the steel beam structure.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.15 no.3
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• pp.169-173
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• 2015

This study is to predict the life exponent by measuring, over 7 years, the insulation resistance of high-voltage cables in 22 kV operation for 13 years. We found out the lifetime index in order to determine the time-dependent trend of deteriorating performance of power cables. The insulation resistances decreased according to elapsed time. We found that: the initial measurements of the cable systems were in agreement with the deterioration properties of the Arrhenius Law. By analyzing the life curve of the cable system, we also verified that the value of the life exponent (n) in the v-t characteristics defined by Weibull distribution has values from 10 to 11. When designing the cable system, the initial value of life exponent was chosen as 9 without any grounding. We have verified that the theoretical grounding based on the design safety of n=9 was actually the best one available. In the short term, we apply our research result to the diagnosis and evaluation of the power cables. In the long run, however, we plan to reduce the cost of the installation and management of cable systems in operation at power stations.

• Korean Journal of Clinical Pharmacy
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• v.8 no.2
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• pp.107-112
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• 1998

Lovastatin is a lipid lowering agent for the treatment of hypercholesterolemia and belongs to a new class of pharmacologic compounds called the 3-hydroxy-3-methylglutaryl coenzyme A (HMG CoA) reductase inhibitors. By competitively inhibiting HMG CoA reductase, lovastatin disrupts the biosynthesis of cholesterol in hepatic and peripheral cells and increases the synthesis of high-density-lipoprotein HDL) receptors. Following oral administration, the lactone ring of lovastatin is hydrolysed to the active inhibitor of HMG CoA reductase, lovastatin acid. Lovastatin is known to have poor oral absorption and wide individual variation. In this study, bioequivalence test of two lovastatin formulations, the test drug ($Lovaload^{TM}$, Chong Kun Dang Pharmaceutical Co.) and the reference drug ($Mevacor^{TM}$, Chung Wae Pharmaceutical Co.) were conducted according to the guidelines of Korea Food and Drug Administration (KFDA). A total of 18 healthy male volunteers, $31.90\pm3.60$ years old and $72.17\;7.88$ kg of body weight in average, were evaluated in a randomized crossover manner with a 2-week washout period. Concentrations of lovastatin acid in plasma were measured upto 12 hours following a single oral administration of eight tablets (20 mg of lovastatin per tablet) by high-performance liquid chromatography with UV detection at 238 nm. The area under the concentration-vs-time curve from 0 to 12 hours $(AUC_{0-12h})$ was calculated by the trapezoidal summation method. The statistical analysis showed that there are no significant differences in $AUC_{0-12h),\;C_{max}\;and\;T_{max}$ between the two formulations ($6.72\%,\;1.52\%,\;and\;0.88\$, respectively). The least significant differences between the formulations at $\alpha$=0.05 were less than $20\%\;(11.65\%,\;19.73\%,\;and\;14.81\%\;for\;AUC_{0-12h},\;C_{max}\;and\;T_{max}$, respectively). The $90\%$ confidence intervals for these parameters were also within $\pm20\%\;(-1.50{\leq}{\delta}{\leq}15.00$, $-12.50{\leq}{\delta}{\leq}15.50,\;and\;-9.64{\leq}{\delta]{\leq}11.40{\leq}\;for\;\;AUC_{0-12h}$ ,$C_{max}\;and\;T_{max}$, respectively). In conclusion, the new generic product $Lovaload^{TM}$ was proven to be bioequivalent with the reference drug.

• Korean Journal of Clinical Pharmacy
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• v.10 no.1
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• pp.13-18
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• 2000

The bioequivalence of two clarithromycin tablets, the $Klaricid^{TM}$ (Ciba-Geigy Korea Ltd.) and the $Pylocin^{TM}$ (Kyungdong Pharmaceutical Co., Ltd.), was evaluated according to the Korean Guidelines for Bioequivalence Test (KGBT 1998). Sixteen healthy male volunteers ($20\sim26$ years old) were randomly divided into two groups and a randomized $2\times2$ cross-over study was employed. After one tablet containing 250 mg of clarithromycin was orally administered, blood sample was taken at predetermined time intervals, and the concentrations of clarithromycin in serum were determined using high-performance liquid chromatographic method with electrochemical detector. The pharmaco-kinetic parameters (area under the concentration-time curve: $AUC_t$, maximum concentration; $C_{max}$ and time to maximum concentration; $T_{max}$) were calculated and analysis of variance (ANOVA) was utilized for the statistical analysis of parameters. The results showed that the differences in $AUC_t,\;C_{max}\;and\;T_{max}$ between two tablets based on $Klaricid^{TM}$ tablet were $-0.22\%,\;-0.48\%\;and\;-1.63\%$, respectively. The powers $(1-\beta)\;for\;AUC_t,\;C_{max}\;and\;T_{max}\;were\;99.07\%,\;88.15\%\;and\;99.99\%$, respectively. Detectable differences $(\Delta)\;and\;90\%$ confidence intervals ($\alpha$=0.10) were all less than $\pm20\%$ All the parameters above met the criteria of KGBT 1998, indicating that $Pylocin^{TM}$ tablet is bioequivalent to $Klaricid^{TM}$ tablet.

• YAKHAK HOEJI
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• v.57 no.4
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• pp.293-298
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• 2013

Hwangryunhaedok-tang (HRT) is a traditional herbal medicine, which has been known as a useful prescription for anti-biotic, anti-inflammatory, anti-oxidative and immunosuppressive activity. In this study, the variation in the amount of eight bioactive components of Hwangryunhaedok-tang (HRT) and its fermentation HRT with Lactobacillus casei KFRI 127, Lactobacillus curvatus KFRI 166 and Lactobacillus confuses KFRI 227 was investigated via high-performance liquid chromatography coupled with diode array detection (HPLC-DAD). Simultaneous qualitative and quantitative analysis of eight bioactive components; geniposide, genipin, baicalin, wogonoside, palmatine, berberine, baicalein and wogonin was achieved by comparing their retention times ($t_R$) and UV spectra with those of the standard components. All calibration curve of standard components showed good linearity ($r^2$ >0.979). As a result, the geniposide amount was $15.52{\pm}0.19{\mu}/mg$ that as a main components in HRT. The wogonoside was decreased by 29.28~58.35% with Lactobacillus casei KFRI 127 and L. confuses KFRI 227 ($3.17{\pm}0.31{\mu}g/mg$ and $3.55{\pm}0.13{\mu}g/mg$) compared with the original HRT ($5.02{\pm}0.14{\mu}g/mg$). Otherwise wogonin was increased by 16.28~41.86% with Lactobacillus casei KFRI 127 and L. confuses KFRI 227 ($0.61{\pm}0.01{\mu}g/mg$ and $0.50{\pm}0.02{\mu}g/mg$) compared with the original HRT($0.43{\pm}0.00{\mu}g/mg$). HRT fermented with L. casei KFRI 127 and L. confuses KFRI 227 were evaluated as creating the changes in wogonoside to that aglycon wogonine. In the fermented HRT using Lactobacillus acidophilus KFRI 166, the genipin was only detected, among 3 species of fermentation strains. Thus, these results considered that the strains 166 were exhibited the remarkable changes in genipin.