• 전력전자학회:학술대회논문집
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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.

• 한국가스학회지
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• 제17권2호
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• pp.50-58
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• 2013

공정플랜트에는 다양한 배관이 고압, 고온의 인화성, 폭발성 물질을 이송하고 있다. 잦은 설계 변경 및 증설 등으로 복잡한 형상으로 배관이 형성되어 있는 경우가 많으나 배관의 구조가 단순하여 실제 위험성에 비해 안전 관리가 부족한 경우가 많다. 본 연구에서는 국내 한 업체에서 부생가스를 연료로 사용하던 배관을 설계 변경하여 천연가스와 혼합하여 사용하도록 사례를 활용하여, 배관의 안전성을 평가 하는 방법을 예시하였다. 배관의 설계 변경 후 안전성을 ASME 기준에 따라 재평가하고, 배관의 주요 관리부위를 결정하는 방법을 제시하였다. 배관의 분기 및 루프 등이 다수 복잡하게 연결되어있는 가스혼합용 믹싱드럼 배관 시스템을 대상으로 해석하였다. 배관의 주요부위 응력 민감도를 이해하기 위해 배관의 지지대 구속조건 및 외부 온도를 변화시켜 가면서 이들의 영향을 연구하였다. 또한 부생가스가 포함하고 있는 수소가스에 의한 손상 가능성에 대해서도 논의하였다.

• 한국안전학회지
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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.

• 한국의사학회지
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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.

• 한국가스학회지
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• 제18권4호
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• pp.56-62
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• 2014

본 연구에서는 촉매가 들어있는 고정층 반응로의 단일 개질관에 대하여 전산 유체 해석(Fluent ver. 13.0)을 수행하여 열/유동 특성을 파악하고, 주입 가스에 따른 추출 가스의 종류를 다공성에 따라 예측하였다. 촉매 형상을 모델링하기 위하여, 개질관 내부에 있는 촉매를 모두 다공성 물질이라고 가정하고, 수정된 Eugun 식을 해석에 적용하였다. 유체의 공극률을 기준으로 0.545, 0.409, 그리고 0.403로 설정하고, 결과를 비 다공성인 경우와 비교하였다. 수치해석 결과, 개질관 벽면의 온도는 흡열반응과 주변 열전달로 인하여 개질관의 온도보다 높게 나타나며, 수소 생성량도 다소 증가했다. 촉매의 공극률이 증가 하게 될 경우, 압력 강하로 인하여 관 중심부 온도 및 수소 생성량이 현저하게 감소하는 경향을 보였다.

• 한국임상약학회지
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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

본 연구는 최근에 활발히 연구가 진행 중인 항공수요 예측을 위하여 계절형 다변량 시계열 모형을 기반으로 하고 다른 모형과의 비교를 RMSE(Root Mean Square Error)를 기준으로 비교한 것이다. 여기서 싱가폴 국제항공유가, 수출액을 추가하여 예측성능을 좋게 하고자 한다.

• 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.

• 한국가스학회지
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• 제20권5호
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• pp.27-33
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• 2016

본 연구의 목적은 실제 산업현장에서 사용되는 수소 개질로 내 개질가스의 수증기-메탄 혼합비에 따른 튜브 내 온도 및 화학반응 특성을 수치 해석하는 것이다. 탄화수소의 수증기 개질반응은 800 K - 1000 K 이상의 고온에서 발생하기 때문에 대류, 전도 및 복사 열전달을 고려한 복합 열전달을 고려해야 한다. 수치해석은 상용 전산유체역학(CFD) 코드(ANSYS Fluent V.13.0)를 사용하였다. 본 연구에서 해석을 위해 Reynolds-Averaged Navier-Stokes, 운동량 및 에너지 방정식을 사용하고, 화학반응이 발생하는 튜브 내부는 니크롬 재질의 다공성 영역으로 가정하였다. 개질 튜브 내 온도 및 화학반응 특성을 비교하기 위해 메탄과 수증기의 혼합비를 1-6으로 증가시켜 비교 분석하였다. 수치해석 결과, 메탄에 대한 수증기 비율이 높을수록 튜브 내부의 온도가 증가하고, 메탄의 전화율이 증가한다. 그러나 수소 개질량은 수증기와 메탄의 비율이 5일 때 가장 많은 것을 알 수 있다.

• 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.