• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2007년도 춘계학술대회
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• pp.5-8
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• 2007

In this paper, numerical investigation has been carried out to study performance of methane autothermal reformer and dynamic behavior for light-off under various operating conditions. In order to simulate the given problems, numerical methods are incorporated using finite-volume method. In addition, porous medium approach is accepted because the catalytic phenomena occur in porous media. Also, start-up issue is significant in autothermal reformer although the reaction is marginally exothermic. Thus, in this study transient behavior has been also investigated to find out optimal operating conditions for start-up.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2007년도 춘계학술대회
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• pp.519-523
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• 2007

Gas(or methane) hydrates are solid solutions when water molecules are linked through hydrogen bonding and create host lattice cavities that can enclose a large variety of guest gas molecules. The natural gas hydrate crystal may exist at low temperature above the normal freezing point of water and high pressure greater than about 30 bars. A lot of quantities of natural gas hydrates exists in the earth and many production schemes are being studied. In the present investigation, depressurization method was considered to predict the production of gas and the simulation of the two phase flow - gas and water - in porous media is being carried out. The simulation show about the fluid flow in porous media have a variety of applications in industry. Results provide the appearance of gas and water production, the pressure profile, the saturation of gas/ water/ hydrates profiles and the location of the pressure front.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2006년도 추계학술대회
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• pp.66-69
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• 2006

The idea of $CO_2$ sequestration in the ocean is proposed to be an effective mitigation strategy to counteract potential global warming due to the greenhouse effect Therefore, in the present study, calculations of the dissolution behavior of $CO_2$ hydrate when liquid carbon dioxide is released at 1,000m and 1,500m in depth are performed. The results show the liquid $CO_2$ injected in the ocean becomes $CO_2$ bubble at between 350m and 500m in depth, and the injection from a moving ship is a more effective method of dissolution than through a fixed pipeline. It so also noted that the ultimate plume generated from $CO_2$ bubbles repeats expansion and shrinking due to the peel ins from a fixed pipeline.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2007년도 추계학술대회 논문집
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• pp.63-66
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• 2007

Reformers which produce hydrogen from natural gas are essential for the operation of residential PEM fuel cells. For this purpose, steam-methane reforming reactions with Ni catalysts is primarily utilized. Commercial Ni catalysts are generally made to have porous pellet shapes in which Ni catalyst particles are uniformly dispersed over Alumina support structures. This study numerically investigates the reduction of catalyst effectiveness due to the mass transport resistances posed by porous structures of spherical catalyst pellets. The multi-component diffusion through porous media and the accurate kinetics of reforming reaction is fully considered in the numerical model. The preliminary results on the variation of the effectiveness factor according to different operation conditions are presented, which is planned to be used to develop correlations in future studies.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2007년도 추계학술대회 논문집
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• pp.268-268
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• 2007

• 대한기계학회논문집B
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• 제30권10호
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• pp.929-934
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• 2006

The digital HPTV(holographic particle tracking velocimetry) velocity field measurement system consists of four steps: recording, numerical reconstruction, particle extraction and velocity extraction. In the velocity extraction process, we improved the two frame PTV algorithm to extract 3-D displacement information of each particle located in 3D space. Because a digital CCD camera was used, some factors such as spatial resolution, numerical aperture, and particle concentration influenced on the performance of the developed digital HPTV. Especially, the particle concentration $(C_o)$ affected the reconstruction efficiency and recovery ratio in the numerical reconstruction and particle extraction procedure. In this paper, the effect of particle concentration reconstruction efficiency and recovery ratio were analyzed experimentally. Optimal particle concentration was found to be in the range of $C_o=11{\sim}17\;particles/mm^3$.

• 신재생에너지
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• 제2권4호
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• pp.4-11
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• 2006

The idea of $CO_2$ sequestration in the ocean is proposed to be an effective mitigation strategy to counteract potential global warming due to the greenhouse effect. Therefore, in the present study, calculations of the dissolution behavior of $CO_2$ hydrate when liquid carbon dioxide is released at 1,000m and 1,500m in depth are performed. The results show the liquid $CO_2$ injected in the ocean becomes $CO_2$ bubble at between 350 m in depth, and the injection from a moving ship is a more effective method of dissolution than through a fixed pipeline. It so also noted that the ultimate plume generated from $CO_2$ bubbles repeats expansion and shrinking due to the peeling from a fixed pipeline.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2003년도 추계학술대회 논문집 전기물성,응용부문
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• pp.264-265
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• 2003

3차원 영상정보처리에 이용되는 변형 삼각간섭계는 인코히어런트 광을 이용한 3차원 영상정보의 기록과 복원에 이용되고 있다. 최근에는 3차원 영상의 기록과 재생이외의 분야, 예를 들면 3차원 물체의 결함 검출 및 현미경분야에 대한 활용 연구도 진행되고 있다. 본 연구에서는 이러한 분야에 응용이 되고 있는 변형 삼각간섭계의 개선과 이에 대한 일반적인 전달함수와 PSF(point-spread function)를 제시하였으며, 변형 삼각간섭계에 대한 복소흘로그램 생성과 수치적 복원영상결과도 제시하였다.

• 한국조명전기설비학회:학술대회논문집
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• 한국조명전기설비학회 2003년도 학술대회논문집
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• pp.265-267
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• 2003

3차원 영상정보처리에 이용되는 변형 삼각간섭계는 인코히어런트 광을 이용한 3차원 영상정보의 기록과 복원에 이용되고 있다. 최근에는 3차원 영상의 기록과 재생이외의 분야, 예를 들면 3차원 물체의 결함검출 및 현미경분야에 대한 활용 연구도 진행되고 있다. 본 연구에서는 이러한 분야에 응용이 되고 있는 변형 삼각간섭계의 시스템개선과 시스템에 대한 전달함수와 PSF(point-spread function)의 일반화를 시도하였으며, 변형 삼각간섭계에 대한 복소홀로그램 생성과 수치적 복원영상결과도 제시하였다.

• Journal of Advanced Marine Engineering and Technology
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• 제35권6호
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• pp.732-739
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• 2011

최근 몇 년간 에너지 위기에 대한 우려가 급격히 증가하고 있으며, 방대한 에너지소비에 따른 환경오염도 큰 문제로 대두되고 있다. 사회적으로 에너지 위기가 고조되고 있는 가운데 새로운 에너지나 신재생에너지에 대한 관심이 증가하고 있다. 본 연구는 이러한 문제를 해결하기 위한 하나의 해결책으로 건물의 난방에 태양열을 적극적으로 이용하기 위한 태양열 흡열다공판을 외벽에 설치하여 실내의 온도를 상승시키기 위한 실험 논문이다. 그리고 태양전지판에 의해 구동되는 실내 공기 순환 팬은 실내의 대류 열전달을 상승시키기 위해 이용된다. 본 연구는 실험과 수치해석으로 구성되어져 있다. 본 연구의 실험결과에서는 입구 공기 온도가 45[$^{\circ}C$]까지 상승하는 것을 알 수 있었다. 이 온도는 겨울철 동안 실내 공기를 상승시키기에 충분하다. 그리고 수치해석을 이용하여 팬의 대류상승효과를 입증하였다.