• Nuclear Engineering and Technology
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• 제55권6호
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• pp.2263-2275
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• 2023

In general, an internal fire events probabilistic safety assessment (PSA) model is quantified by modifying the pre-existing internal event PSA model. Because many pieces of equipment or cables can be damaged by a fire, a single fire event can lead to multiple internal events PSA initiating events (IEs). Consequently, when the fire events PSA model is quantified, inappropriate minimal cut sets (MCSs), such as duplicate MCSs, may be generated. This paper shows that single quantification of a hypothetical single-top fire event PSA model may generate the following four types of inappropriate MCSs: duplicate MCSs, MCSs subsumed by other MCSs, nonsense MCSs, and MCSs with over-counted fire frequencies. Among the inappropriate MCSs, the nonsense MCSs should be addressed first because they can interfere with the right interpretation of the other MCSs and prevent the resolution of the issues related to the other inappropriate MCSs. In addition, we propose a resolution process for each of the issues caused by these inappropriate MCSs and suggest an overall procedure for resolving them. The results of this study will contribute to the understanding and resolution of the inappropriate MCSs that may appear in the quantification of fire events PSA models.

• 한국결정성장학회지
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• 제14권6호
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• pp.262-266
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• 2004

초기 RF유도가열을 위해 Ti 금속링을 사용하여 스컬법에 의해 루릴 단결정을 성장시켰다. 성장시킨 단결정은 ${\varnothing}55.5{\times}1.0mm$의 wafer로 가공하였으며,$1300^{\circ}C$에서 15시간까지 대기중에서 열처리 하여 $\lambda=200~25000nm$의 범위에서 투광도를 비교하였다.

• 한국염색가공학회지
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• 제8권6호
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• pp.55-64
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• 1996

The compression properties of the 2 folded yams such as compression linearity, compression resilience, and compression work with various wool/polyester blend ratios and with single and 2-folded yarn twists under various degrees of twisting were studied for analyzing twist characteristics, inter and intra frictional effects. A variation of single and 2-folded yarn twists was analysed in their twist structure. This structural analysis was discussed with various wool/polyester blend ratios and various single and 2-folded yarn twists.

• 대한전기학회논문지:전기기기및에너지변환시스템부문B
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• 제55권12호
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• pp.596-607
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• 2006

This paper presents Single Phase Switched Reluctance Motor (SPSRM) optimum design for vacuum cleaners using Response Surface Methodology (RSM) to determine geometric parameters, and the 2-D Finite Element Method (FEM) has been coupled with the circuit equations of the driving converter. Additionally, an optimum process for SPSRM has been proposed and peformed with geometric and electric parameters thereby influencing the inductance variation and effective torque generation as design variables. SPSRM performances have also been analyzed to determine an optimal design model for maximized efficiency at high power factor. In order to confirm the propriety of the Finite Element Method and motor performance calculation, simulation waveform and experiment waveform for motor voltage and current were compared.

• 대한방사선기술학회지:방사선기술과학
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• 제20권1호
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• pp.55-59
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• 1997

The quality of continuous X-ray beam depends upon the half value layer which varies according to the geometric conditions, filtration thickness, and tube voltage. We compared the inverter type X-ray equipment with the conventional single phase 2 peak and the three phase 12 peak for the quality obtained by changes of the added filter thickness and the tube voltage. The quality of single phase 2 peak X-ray generator showed increase for the added filter and the tube volt-age. The half value layer is Increased the thicker the filter and the higher the kVp. The quality of the Inverter type and the three phase 12 peak in comparison with the single phase 2 peak X-ray generator is increased.

• 에너지공학
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• 제24권4호
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• pp.55-62
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• 2015

It is expected that the size of welding defect affects the mechanical performance of welded medium density polyethylene (MDPE) pipe joints. In this study, butt fusion welded MDPE pipe joints with a single spherical or planar defect of various sizes were studied using experimental crush testing and also by finite element method. The crush test showed that the mechanical performance of crush was not affected by the size and geometry of a single welding defect when the defect size was increased to 45% of the pipe's wall thickness. The simulation results indicated that the effect of the single welding defect on the Von Mises stress distribution near the defect explained the reason of the test results.

• 대한전기학회논문지:전기물성ㆍ응용부문C
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• 제55권7호
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• pp.359-363
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• 2006

Single-walled carbon nanotubes (SWCNTs) with few defects and very small amount of amorphous carbon coating have been synthesized by catalytic decomposition of methane in $H_2$ over well-dispersed metal particles supported on MgO. The yield of SWCNTs was estimated to be 88.5% and the purities of SWCNTs thus obtained were more than 90%. Peak of the radial breathing mode in the Raman spectrum demonstrated that the diameters of synthesized CNTs are in the range 0.4-2.0 nm. Our results also indicated that MgO support materials are useful to a large-scale synthesis of high-quality SWCNTs. Increasing temperature could remarkably increase the yield and also improve the quality of SWCNTs from catalytic decomposition of methane. The morphologies and microstructures of the synthesized carbon materials were characterized by scanning electron microscopy (SEM), Thermogravimetric analysis (TGA), Raman spectroscopy, and X-ray diffraction (XRD).

• 대한전기학회논문지:전기기기및에너지변환시스템부문B
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• 제55권8호
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• pp.430-435
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• 2006

This paper presents a method about the efficiency analysis and the harmonic reduction of single phase NPC multi-level inverter with LC-trap filter and LCR output filter. The proposed LC-trap filter is comprised of a conventional LC output filter, by using LC-trap filter the need for high damping resistor and low LC cut-off frequency is eliminated. Also, low damping resistor is increased the efficiency of the output filter. Experimental verification of the proposed circuit is provided with single phase NPC multilevel inverter system and DSP controller.

• 한국식품조리과학회지
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• 제29권2호
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• pp.193-208
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• 2013

The purpose of this study was to investigate the characteristics and brewing methods of Danyangju, which is one of the traditional single brewed rice liquors using Korean ancient literatures publishes from the 1400's to 1600's. Total 32 Danyangju products and 55 brewing methods were found by reviewing the ancient literatures. Danyangju products could be classified into four groups depending on type of grain used: 1) 13 Danyangju products with non-glutinous rice, 2) 14 products with waxy rice, 3) 4 products with mixture of waxy and nonwaxy rice, and 4) 2 products with barley. In this paper, not only ingredients, formula and utensils needed for preparation of Danyangju, but also brewing characteristics and terminology were reviewed. The findings on Danyangju in this study would be useful to improve the brewing methods and quality of Korean traditional liquors.

• 한국주거학회논문집
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• 제17권6호
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• pp.55-63
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• 2006

The purpose of this study is to investigate the change of kitchen in a single detached house in Jeonju city after 70's. Oral life history method which has 12 women's personal narratives and 17 women's personal narratives with written reports was used as a research method of this study. The results of the study were obtained as follows: 1) It was beginning about late 1970 year that heating system and cooking place were separated in a house. 2) Many kitchens were reconstructed for indoor stand-up work place from late 1970's to the early 1980's. 3) There were major factors such as heating system, cooking fuel, and work center in the change of kitchen in old houses. 4) The kitchen toward the center with a living room was appeared in the floor plan of modem house after 1990's. The symbolic words of the indoor kitchen that work for women were 'warmness' and 'convenience'.