• Proceedings of the KSME Conference
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• 2001.06d
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• pp.738-743
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• 2001

A computer program, capable of performing thermal design analysis of the triple pressure bottoming system of combined cycle power plants, was developed. The program is based on thermal analysis of the heat recovery steam generator and estimation of its size and steam turbine power. The program is applicable to various parametric analyses including optimized design calculation. This paper presents examples of analysis results for the effects of arrangement of heat exchanger units, steam pressures and deaerating sources on design performance indices such as steam turbine power and the size of heat recovery steam generator.

• Journal of Advanced Marine Engineering and Technology
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• v.15 no.5
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• pp.30-37
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• 1991

Steam ejector systems are widely used for the evacuation systems because of their high working confidence and simlicity. And recently these are used as the thermo-compressors in various energy saving systems. In this practical experiment, we have obtained the results as follows : (1) The velocity coefficient of the motive steam nozzle was 0.92-0.98. (2) The optimal area ratio was 0.00625 at pressure ratio 5.2 and expansion ratio 101.3. (3) The performance and efficiency of the steam ejector were mainly affected by the axial position of nozzle. (4) The good performance of the domestic manufactured steam ejector was confirmed in comparison with the foreign one. And by experimental results, we have carried out the improvement of Computer Aided Design Program of steam ejector which will be helpful for systematic research into the steam ejector.

• 제어로봇시스템학회:학술대회논문집
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• 1996.10b
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• pp.156-159
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• 1996

An adaptive predictive control for steam-reforming plant which consist of a steam-gas reformer and a waste heat steam-boiler was studied by using MIMO bilinear model. The simulation experiments of the process identification were performed by using linear and bilinear models. From the simulation results it was found that the bilinear model represented the dynamic behavior of a steam-reforming plant very well. ARMA model was used in the process identification and the adaptive predictive control. To verify the performance and effectiveness of the adaptive predictive controller proposed in this study the simulation results of steam-reforming plant control based on bilinear model were compared to those of linear model. The simulation results showed that the adaptive predictive controller based on bilinear model provides better performance than those of linear model.

• Proceedings of the Korean Society of Computer Information Conference
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• 2013.07a
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• pp.215-217
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• 2013

21세기 지식 정보 사회에서는 다양한 학문 분야의 영역을 넘나드는 융합적이고 창의적인 사고를 하는 통섭적인 인재가 필요하다. 이에 우리나라에서는 STEAM 교육을 강화하고 있는 추세이고 관련된 연구도 활발히 이루어지고 있다. 그러나 대부분 과학중심의 STEAM 교육이 이루어지고 있는 실정이다. 예술을 통해 얻는 교육적 가치를 고려해 볼 때 STEAM 교육에서 예술을 보조적 수단으로 여기는 경향은 개선되어야 한다고 생각한다. 이에 본 연구에서는 스크래치와 로봇을 활용한 예술 교과 중심의 STEAM 교육 프로그램을 설계하고자 한다.

• Journal of Korean Elementary Science Education
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• v.34 no.2
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• pp.194-209
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• 2015

본 연구의 목적은 스크래치 프로그래밍을 활용한 초등과학 '작은 생물' STEAM 수업을 개발하고 적용하여, 초등 영재학생의 창의적 인성, 창의적 문제해결력, 과학적 태도의 향상에 어떠한 영향을 미치는지 알아보고자 하였다. 개발한 STEAM 수업은 과학 지식과 스크래치 프로그래밍을 통합한 내용적 융합의 방법을 통해 학습자가 창의적 설계와 감성적 체험을 효과적으로 경험할 수 있도록 설계되었다. 연구 대상은 26명의 초등과학 영재학생들이었으며, 양적 및 질적 접근을 통해 자료를 수집하였다. 7차시의 수업을 적용한 결과, 개발한 STEAM 수업이 창의적 인성 및 과학적 태도에 효과가 있었다. 창의적 인성 하위 요소 중, 독립성에서 효과가 있었으며, 과학적 태도 측면에서는 자발성 및 인내심에서 유의한 상승을 보였다. 본 연구는 생명 과학 및 컴퓨터 프로그래밍처럼 STEAM 수업을 위한 효과적인 수단을 통합하는 일이 과학 기술에 대한 학생들의 창의성과 흥미를 신장시킬 수 있음을 제안한다.

• Proceedings of the KSME Conference
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• 2003.04a
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• pp.2174-2179
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• 2003

For many years, T/G Supplier has constructed a number of thermal power plants and researched to improve the performance and the reliability of steam turbine, which are achieved by advances in design and materials technology. In recent, interest is renewed in advanced steam condition as means of improving economy of thermal power plant and reducing environmental pollution. Improvements in the maximum power have been driven by the development of advanced rotor and bucket material and longer last stage bucket. Improvements in efficiency have been brought through advances in mechanical efficiency and thermodynamic efficiency. This paper describes a number of new steam path design features introduced to the steam turbine product. And also this paper describes new design technologies' development, new technologies' trend and technologies' development for ultra-super critical steam turbine.

• Journal of Fisheries and Marine Sciences Education
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• v.28 no.1
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• pp.69-82
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• 2016

In this study, Art area -based STEAM education programs that take advantage of the Scratch was to analyze the effect of the development of elementary school students' creativity. The winter break of ${\bigcirc}{\bigcirc}$ university education donation application students 3, 4, 5th grader was verified two research hypothesis to the target. First, Art area -based STEAM education programs will be effective on the development of elementary school students' creativity. Second, Art area -based STEAM education programs will be more effective on the development of the elementary school girls' creativity than the elementary school boys' creativity. Art area -based STEAM education programs is to show a significant difference on the development of elementary school students' creativity, mean change of elementary school girls were remarkable than boys.

• Journal of the Korean institute of surface engineering
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• v.35 no.6
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• pp.363-370
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• 2002

Empirical equations for the oxide thickness and the weight gain of Zircaloy-4 cladding during the oxidation in high temperature, high pressure steam have been developed. Firstly, the empirical equations for oxide thickness in 1 atm steam in 700~100$0^{\circ}C$ were made, then, the enhancement factor for the steam pressure effects on Zircaloy-4 cladding oxidation in high temperature steam was added. Based on the analysis of the weight fraction of dissolved oxygen in metal layer, empirical equations for the weight gain of Zircaloy-4 in high pressure, high temperature steam were developed. We compare the developed empirical equations with the Baker-Just correlation. The Baker-Just correlation can give a non-conservative estimation of oxidation of Zircaloy-4, depending on the steam pressure. These developed empirical equations can be used for the correct estimation of oxidation of Zircaloy-4 during accident analysis.

• Transactions of the Korean Society of Pressure Vessels and Piping
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• v.13 no.2
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• pp.31-37
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• 2017

The heat transfer function or thermal performance is the most important function of the steam generator component in nuclear power plants. The declining of thermal performance, fouling does not affect the electric power of the nuclear power plant within a certain fouling level, but it affects the output when goes beyond the governor valve wide open of the turbine. The VWO steam pressure can be predicted through the thermal performance evaluation of steam generators in the nuclear power plant. In consideration of the fouling characteristics of the steam generator, methods of the thermal performance evaluation and fouling cases are reviewed, and also the critical VWO value is estimated through the actual thermal performance evaluation. It is necessary to apply the VWO theory based on the thermal performance of the steam generators.

• Textile Coloration and Finishing
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• v.18 no.6 s.91
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• pp.25-30
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• 2006

Degumming is an essential process to improve the luster and smoothness of the silk filament. Silk varieties were degummed using different methods. A number of methods, from pad-steam to specific alkaline are being used for this propose. In this paper an attempt to compare the efficiencies of different degumming processes has been made. from the results, it may be observed that when silk fabrics were pad-steam, the degree of degumming, as assessed by weight loss. When the pad-steam degumming was carried out at different pHs, adjusted using alkalies, it was observed that at higher pH the weight loss is high. Pad-steam degumming as well as star degumming was found to be superior with minimum damage to the substrate. Among the alkalis used, the sodium carbonate gives the best results, since the weight loss is almost maximum with lower strength loss by over degumming. It is also efficient from the point of view of conservation of heat energy and time as against the comparable star degumming.