• 한국수소및신에너지학회논문집
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• 제22권4호
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• pp.546-551
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• 2011

The corrosion on steam generator tubes of the secondary side of pressurized water reactor inhibits heat transfer. One of the most efficient techniques improving the heat transfer performance of a nuclear electric generation is a corrosion control. The environmental parameters mostly affecting corrosion are materials and chemical additives. It seems that no further corrosion occurs in steels with Polyacrylic acid polymer dispersant treatment. Polyacrylic acid forms a protective coating with uniform thickness on metal surface. Polyacrylic treatment appears to be the most convenient way to enhance the thermal performance by the thermal conductivity improvement in steam generators.

• 한국디지털정책학회:학술대회논문집
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• 한국디지털정책학회 2007년도 춘계학술대회
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• pp.171-180
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• 2007

The purpose of this paper is to find an policy vision and action plans for the growth of the Korean cultural contents industry as a new growth power in the 21th century. For this purpose, I referred to sundry records to analyze the characteristics, industrial situation and the prospects of the cultural contents industry. I also made an analysis on the outcome of the cultural contents policy with the help of the official concerned in the Ministry of Culture and Tourism, which made it possible for me to draw a few urgent problems of Korean cultural contents industry. With these preceding analyses, I proposed the strategy and action plans of the government policy for the Korean cultural contents industry as follows : strengthening the creative power of the cultural contents industry, systemizing the healthy circulation of the cultural contents, and improvement of the cultural welfare on the basis of contents.

• 시스템엔지니어링학술지
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• 제14권2호
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• pp.49-57
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• 2018

The main objective of this paper is come up with methodology approach for FPGA-based system in verification and validation lifecycle regarding software reliability using system engineering approach. The steps of both reverse engineering and re-engineering are carried out to implement an FPGA-based of safety critical system in Nuclear Power Plant. The reverse engineering methodology is applied to elicit the requirements of the system as well as gain understanding of the current life cycle and V&V activities of FPGA based-system. The re-engineering method is carried out to get a new methodology approach of software reliability, particularly Software Reliability Growth Model. For measure the software reliability of a given FPGA-based system, the following steps are executed as; requirements definition and measurement, evaluation of candidate reliability model, and the validation of the selected system. As conclusion, a new methodology approach for software reliability measurement using software reliability growth model is developed.

• KEPCO Journal on Electric Power and Energy
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• 제6권2호
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• pp.105-114
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• 2020

• Corrosion Science and Technology
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• 제10권4호
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• pp.151-155
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• 2011

The iron oxide particles could be resulted from the corrosion of the circulating water system of a power plant. Because it may be one of the trouble materials which affect the power generation efficiency due to the deposition on steam generator tube and turbine blade, the continuous observation of its concentration is very important. The laser induced break-down detection (LIBD) technology was applied to monitor continuously the concentration of corrosion products with the detection limit of ppb level. The measurement system consists of a Nd:YAG pulsed laser, a polarizing beam splitter, a flow-type sample cell, an acoustic emission sensor, a high speed data acquisition board, a personal computer, etc.. The performance test results confirmed that this technology can be effective to monitor the corrosion product concentration of the circulating water system of a power plant.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2009년도 춘계학술대회 논문집
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• pp.806-812
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• 2009

Availability of reliable and affordable energy supply is a prerequisite for economic growth. Renewables are the third largest contributor to global electricity production after coal and natural gas and account for a share of 18%. Power generating capacity from renewables has increased to around 900GW by the year 2007. Today biodiesel fuels have been in commercial use in many countries and recently the world-wide biodiesel market has experienced considerable growth, which is partly due to various tax concession programs and other financial incentives. In Korea, biodiesel has already been used for transportation fuel, but not used for power generation fuel yet. Korean government has a strategy for renewable energy propagation, especially the goal of power generation amount by renewable energy is 3% of total power production by 2012. This paper focuses on the feasibility study for adaptability and strategy of using biodiesel as power generation fuel. The study also has the plan to replace the fuel of thermal power plant, gas turbine and distributed power system. As the increase of biodiesel fuel, I look forward to environment-friendly power generation and the strategy of Renewable Portfolio Standards(RPS).

• 신재생에너지
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• 제5권1호
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• pp.32-39
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• 2009

Availability of reliable and affordable energy supply is a prerequisite for economic growth. Renewables are the third largest contributor to global electricity production after coal and natural gas and account for a share of 18%. Power generating capacity from renewables has increased to around 900GW by the year 2007. Today biodiesel fuels have been in commercial use in many countries and recently the world-wide biodiesel market has experienced considerable growth, which is partly due to various tax concession programs and other financial incentives. In Korea, biodiesel has already been used for transportation fuel, but not used for power generation fuel yet Korean government has a strategy for renewable energy propagation, especially the goal of power generation amount by renewable energy is 3% of total power production by 2012. This paper focuses on the feasibility study for adaptability and strategy of using biodiesel as power generation fuel. The study also has the plan to replace the fuel of thermal power plant, gas turbine and distributed power system. As the increase of biodiesel fuel, I look forward to environment-friendly power generation and the strategy of Renewable Portfolio Standards(RPS).

• 동력기계공학회지
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• 제7권4호
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• pp.55-60
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• 2003

This paper is to investigate the fatigue crack growth of plasma-sprayed coating steels according to heat treatments. The experimental materials are carbon steels(substrate: S45C) with plasma-sprayed coating layers of Ni-4.5%Al and $TiO_2$. The fatigue test is conducted on compact tension specimen by a servo-hydraulic fatigue testing machine. The specimens are heat-treated at $400^{\circ}C\;and\;800^{\circ}C$, respectively. Loading condition is a constant amplitude sinusoidal wave with a frequency of 10Hz and a load ratio of 0.1. The fatigue crack growth length is automatically measured by a compliance method. In the case of non-heat treated specimens, the fatigue crack growth rates of both substrate and coating specimen are almost same. The crack growth rates of substrates and coating steels by heat treatment are larger than those of the non-heat treated one, because the ductile property increase by heat treatment. In ${\Delta}K<18MPa{\cdot}m^{1/2}$, the crack growth rates of the heat-treated specimens are slightly taster than non-heat treated one. But the both heated and non-heated one are almost same in ${\Delta}K>18MPa{\cdot}m^{1/2}$.

• 동력기계공학회지
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• 제18권2호
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• pp.62-69
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• 2014

In this paper, in order to investigate the effects of marco and microscopic observations of fatigue crack growth in friction stir welded (FSWed) 7075-T651 aluminum alloy plates, fatigue crack growth tests were performed under constant amplitude loading condition at room temperature with three different pre-cack locations, namely base metal (BM-CL) and two kinds of pre-crack locations in welded joints, weld metal (WM-CL) and heat affected zone (HAZ-CL) specimens. The fatigue crack growth behavior of FSWed 7075-T651 aluminum alloy plates were discussed based on the marco and microscopic fractographic observations. The marcoscopic aspects of surface crack growth path for BM-CL and HAZ-CL specimens indicate relatively straight lines, however, the crack growth paths of WM-CL specimens grow first straight and by followed toward the TMAZ and HAZ. The microscopic aspects of fatigue fracture for BM-CL and HAZ-CL specimens indicate typical fatigue striation, but WM-CL showed intergranular fracture pattern by micro structural changes of FSW process.

• 한국진공학회지
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• 제14권2호
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• pp.84-90
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• 2005

분자선에피를 이용한 $In_{0.2}Ga_{0.8}N/GaN$ 이종접합 구조의 에피성장에 미치는 플라즈마의 rf전력의 영향에 대해 고찰하였다. 플라즈마를 발생시키는 rf 전력과 플라즈마 챔버압력의 조건에 따라 성장표면에 도달하는 분자나 원자의 에너지와 flux가 조절되어 에피성장 속도와 물질적 특성을 변화시킨다. 전력이 너무 낮거나 높은 조건에서 표면거칠기와 광특성이 각각 저하된 결과를 보였으며, 적정한 전력인 400W에서 성장한 $In_{0.2}Ga_{0.8}N/GaN$이 종접합 구조에서 날카로운 계면과 강한 photoluminescence 피크를 보였다. 이러한 현상에 대한 원인으로 고에너지 입자들이 성장표면에서 작용하는 기구들인 플라즈마에 의한 탈착과 표면확산, 성장표면의 하부에 주입되는 결함의 발생에 대하여 논하였다.