• Proceedings of the KIPE Conference
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• 전력전자학회 2016년도 전력전자학술대회 논문집
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• pp.259-260
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• 2016

본 논문은 30kW, 95GHz 자이로트론 구동을 위한 전원 시스템 설계 및 실험에 대하여 기술한다. 효율적인 자이로트론 구동을 위해 개발된 아래 사양의 세 전원장치의 상세 설계, 제작 및 저항부하 실험결과를 제시한다. - Cathode Power Supply (CPS: 50kV, 100kW) - Body Power Supply (BPS: 25kV, 250W) - Heater Power Supply(HPS: 10V, 10A, 50kV Isolation) 또한 현재 수행 중인 자이로트론 구동 실험결과를 통해 개발된 전원장치의 성능을 검증한다.

• Journal of the Korean Institute of Gas
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• 제17권2호
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• pp.50-58
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• 2013

Various process piping usually carries out high flammable and explosible gas under high pressure and high temperature. Due to frequent change of design and structure it becomes more complicated and compactly located. The safety management level is relatively low since it is considered as simply designed component. In this study a safety assessment procedure is proposed for complicated piping system around a mixing drum in which natural gas and by-product gases were mixed. According to ASME code, pipe stress analysis was conducted for determining design margin at some key locations of the piping. These high stress locations can be used as major inspection points for managing the pipe integrity. Sensitivity analysis with outside temperature of the pipe and support constraint condition. Possible effect of hydroen gas to the pipe steel during the previous use of the by-product gas was also discussed.

• Journal of the Korean Society of Safety
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• 제28권3호
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• pp.44-50
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• 2013

Process gas piping is one of the most basic components frequently used in the refinery and petrochemical plants. Many kinds of by-product gas have been used as fuel in the process plants. In some plants, natural gas is additionally introduced and mixed with the byproduct gas for upgrading the fuel. In this case, safety or design margin of the changed piping system of the plant should be re-evaluated based on a proper design code such as ASME or API codes since internal pressure, temperature and gas compositions are different from the original plant design conditions. In this study, series of piping stress analysis were conducted for a process piping used for transporting the mixed gas of the by-product gas and the natural gas from a mixing drum to a knock-out drum in a refinery plant. The analysed piping section had been actually installed in a domestic industry and needed safety audit since the design condition was changed. Pipe locations of the maximum system stress and displacement were determined, which can be candidate inspection and safety monitoring points during the upcoming operation period. For studying the effects of outside air temperature to safety the additional stress analysis were conducted for various temperatures in $0{\sim}30^{\circ}C$. Effects of the friction coefficient between the pipe and support were also investigated showing a proper choice if the friction coefficient is important. The maximum system stresses were occurred mainly at elbow, tee and support locations, which shows the thermal load contributes considerably to the system stress rather than the internal pressure or the gravity loads.

• The Journal of Korean Medical History
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• 제23권2호
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• pp.71-79
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• 2010

The purpose of this paper is to inquire into the significance of Euibangyoochui, Sejo Edition. One cannot study Euibangyoochui, Sejo Edition firsthand since it does not exist today. Instead, this writer looked into the process by which the Sejo Edition had been proofread and the historic figures who led the proofreading process. The quantities of the Sejong Edition and Sejo Edition have been compared, of which the meaning has also been studied. 1. The compilation of Sejo Edition began in 1459(5th year of Sejo), the year King Sejo entrusted the work of proofreading of Euibangyoochui to Yang Seong Ji. This was not a continuance from the work of King Sejong, but a whole new business ignited by the will and necessity conveyed by King Sejo himself. 2. King Sejo regarded medicine important and emphasized its practicality. The fact that the 365 volumes of the Sejong Edition was reduced to 266 volumes reflects the emphasis put on practicality. 3. Yang Seong Ji, who led the proofreading process, played an important role in managing state documents from the time of King Sejo. His compilation, Euibangyoochui, Sejo Edition, is a work that can be discriminated from its Chinese counterpart in that it had been proofread.

• Journal of the Korean Institute of Gas
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• 제18권4호
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• pp.56-62
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• 2014

The present study investigated numerically heat and mass transfer characteristics of a fixed bed reactor by using a computational fluid dynamics (CFD) code of Fluent (ver. 13.0). The temperature and species fraction were estimated for different porosities. For modeling of the catalyst in a fixed bed tube, catalysts were regarded as the porous material, and the empirical correlation of pressure drop based on the modified Eugun equation was used for simulation. In addition, the averaged porosities were taken as 0.545, 0.409, and 0.443 and compared with non-porous state. The predicted results showed that the temperature at the tube wall became higher than that estimated along the center line of tube, leading to higher hydrogen generation by the endothermic reaction and heat transfer. As the mean porosity increases, the hydrogen yield and the outlet temperature decreased because of the pressure drop inside the reformer tube.

• Korean Journal of Clinical Pharmacy
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• 제16권2호
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• pp.101-106
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• 2006

The aim of the present study was to evaluate the bioequivalence of two talniflumate preparations. We used Somalgen tablet (Kun Wha Pharmaceutical Co., Korea.) as a reference drug for bioequivalence of Crimain tablet (Samjini Pharmaceutical Ind. Co., Korea), and performed this whole study according to the guidelines of Korea Food and Drug Administration (KFDA). Twenty four healthy male volunteers, $22.8{\pm}2.2$ years in age and $64.6{\pm}5.3\;kg$ in body weight, were divided into two groups and a randomized $2{\times}2$ cross-over study was employed. After one tablet containing 370 mg of talniflumate was orally administered, blood was taken at predetermined time intervals and the concentrations of talniflumate in plasma were determined using HPLC method with UV-detector. The analysis system was validated in specificity, accuracy, precision and linearity. These items of the analysis condition in this study conform to the guideline of KFDA. The pharmacokinetic parameters such as $AUC_t\;and\;C_{max}$ were calculated using the analysis condition we established and ANOVA test was utilized for the statistical analysis of the parameters using logarithmically transformed $AUC_t$ and Cmax. $Mean{\pm}SD$ of reference drug and test drug in $AUC_t\;and\;C_{max}$ value were $1.27{\pm}0.58\;({\mu}g/ml{\cdot}hr)\;and\;0.27{\pm}0.13\;({\mu}g/ml)$ and $1.14{\pm}0.46\;({\mu}g/ml{\cdot}hr)\;and\;0.26{\pm}0.10\;({\mu}g/ml)$ respectively. The 90% confidence intervals using logarithmically transformed data were within the acceptance range of log(0.8) to log (1.25) for $AUC_t\;and\;C_{max}$, respectively. These results indicate that Samjin talniflumate tablet is bioequivalent to reference drug, Somalgen tablet.

• Communications for Statistical Applications and Methods
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• 제17권3호
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• pp.473-481
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• 2010

Forecasting for air demand such as international passengers and freight has been one of the main interests for air industries. This research has mainly focus on the comparison of the performances of the multivariate time series models. In this paper, we used real data such as exchange rates, oil prices and export amounts to predict the future demand on international passenger and freight.

• Journal of Species Research
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• 제5권2호
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• pp.223-234
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• 2016

As a subset work for the collection of indigenous prokaryotic species in Korea, 38 actinobacterial strains were isolated from various environmental samples obtained from plant root, ginseng cultivating soil, mud flat, freshwater and seawater. Each strain showed higher 16S rRNA gene sequence similarity (>99.1%) and formed a robust phylogenetic clade with closest actinobacterial species which were defined and validated with nomenclature, already. There is no official description on these 38 actinobacterial species in Korea. Consequently, unrecorded 37 species of 24 genera in the 12 families belonging to the order Actinomycetales of the phylum Actinobacteria were found in Korea. Morphological properties, basic biochemical characteristics, isolation source and strain IDs are described in the species descriptions.

• Journal of the Korean Institute of Gas
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• 제20권5호
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• pp.27-33
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• 2016

The aim of numerical study is the investigation of the solid and fluid temperatures in a reformer tube and chemical reaction characteristics of different steam-carbon ratio. We considered conjugate heat transfer contain radiation, convection and conductive heat transfers. This is because steam reforming reaction of hydrocarbon occurred high temperature conditions up to 800 K- 1000 K by using commercial computational fluid dynamics (CFD) code (Fluent ver. 13.0). For numerical simulation, the Reynolds-Averaged Navier-Stokes, momentum and energy equation were employed. In addition, inside of reformer tube is assumed as the porous medium to consider the Nichrome-based catalyst. To analysis characteristics of tube temperature in chemical reaction, we changed steam-methane ratio(SCR) from 1 to 6. As increased SCR, the higher tube temperature and methane conversion were observed. It was obtained that the highest hydrogen production held in SCR of 5.

• Biomolecules & Therapeutics
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• 제15권1호
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• pp.58-64
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• 2007

The previous study reported the biological effect of magnetic field exerted by acting on endocrine and anti-oxidant system. The present study aims to study whether ELF-MF (extremely low frequency magnetic field) affects the physiological endocrine systems such as thyroid and whether ELF-MF affects the defense system against oxidative stress when it alters the function of thyroid. Finally, we correlate the effects of MF on oxidative stress, and adrenal and thyroid with an environmental stress factor. We exposed sham or MF to rats for 5 or 25 days. After the exposure, we determined pain sensitivity, level of TSH, $T_3$ and free $T_4$ in plasma. We also assayed in whole brain, lipid peroxidation, the activity of enzymatic anti-oxidant defense including superoxide dismutase(SOD) and glutathione peroxidase (GPx), and non enzymatic defense such as reduced or oxidized glutathione contents. MF induced the hypersensitivity to thermal stimuli with the reduction of latency. $T_3$ and $T_4$ levels were also increased by the exposure of MF. In addition, we observed the rise of MDA level in rat brain by MF although the MF did not change superoxide dismutase and glutathione peroxidase activity. The effect of MF on both reduced and oxidized glutathione results in decrease in reduced or oxidized glutathione in whole brain. In every experiment, there was no significant difference in MF influence between short term (5 days) and long term (25 days) exposure. Taken together, MF exposure affects the thyroid hormonal control in brain. The elevated thyroid hormone acts on brain, leading to hyper-utilization of oxygen. This phenomenon may be correlated with oxidative stress resulting from MF exposure. In conclusion, we suggest that MF exposure may be an environmental stress by exerting oxidative stress.