• 한국태양에너지학회 논문집
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• 제29권2호
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• pp.47-54
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• 2009

The amount of incident rays over inclination according to direction has been widely utilized as important data m installing solar thermal systems. To optimize the incident solar radiation, the slope, that is the angle between the plane surface in question and the horizontal, and the solar azimuth angles are needed for these solar thermal systems. This is because the performance of the solar thermal systems in much affected by angle and direction of incident rays. Recognizing that factors mentioned above are of importance, actual experiment on the moving route of the sun have been performed in this research to obtain the angle of inclination with which the maximum incident rays can be absorbed. After all, the standard for designing highly optimized solar thermal systems will be provided for designers and employees working in the solar collector related industries.

• 한국태양에너지학회 논문집
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• 제27권1호
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• pp.11-17
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• 2007

The amount of incident rays over inclination according to direction has been widely utilized as important data in installing photovoltaic systems. This is because the performance of the photovoltaic systems in much affected by angle and direction of incident rays. Recognizing that factors mentioned above are of importance, actual experiment on the moving route of the sun have been performed in this research to obtain the angle of inclination with which the maximum incident rays can be absorbed. After all, the standard for designing highly optimized photovoltaic systems will be provided for designers and employees working in the photovoltaic module related industries.

• Coupled systems mechanics
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• 제11권6호
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• pp.543-556
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• 2022

Delamination of multilayered inhomogeneous beam that exhibits non-linear relaxation behavior is analyzed in the present paper. The layers are inhomogeneous in the thickness direction. The dealamination crack is located symmetrically with respect to the mid-span. The relaxation is treated by applying a non-linear stress-straintime constitutive relation. The material properties which are involved in the constitutive relation are distributed continuously along the thickness direction of the layer. The delamination is analyzed by applying the J-integral approach. A time-dependent solution to the J-integral that accounts for the non-linear relaxation behavior is derived. The delamination is studied also in terms of the time-dependent strain energy release rate. The balance of the energy is analyzed in order to obtain a non-linear time-dependent solution to the strain energy release rate. The fact that the strain energy release rate is identical with the J-integral value proves the correctness of the non-linear solutions derived in the present paper. The variation of the J-integral value with time due to the non-linear relaxation behavior is evaluated by applying the solution derived.

• 에너지공학
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• 제23권4호
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• pp.123-129
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• 2014

국내에서도 에너지절약성과 보증계약 방식 위주의 역량강화를 위한 측정 검증(M&V)이 중요한 과제로 부각됨에 따라 선진국과 같은 M&V 방법의 선택과 적용이 필요하다. 국내 ESCO 산업의 역량강화를 촉진하기 위해 에너지절약성과에 대한 M&V를 위해서, 적합한 M&V 선택 및 적용방안의 제시가 요청되고 있다. 본고에서는 IPMVP, 미국 및 일본 사례를 참조하여 국내의 M&V 적용목표 및 적용방향을 설정하고, 적용절차 및 유의사항을 설명한 뒤 M&V 방안(A, B, C, D)의 선택 및 검증방안을 제시하였다. 향후 연구과제로 앞에 제시된 M&V 선택 및 적용방안을 기초로 한 M&V 계획서 및 결과서 작성을 위한 가이드라인 제시방안이 마련될 필요가 있다.

• 대한건축학회논문집:계획계
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• 제34권8호
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• pp.13-22
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• 2018

The purpose of this study was to consider the energy generation of the building as well as the energy demand of the building in terms of zero energy building design. The reason why the zero energy building viewpoint should be discussed is that direction of the building, heat transfer rate of the building, and the S/V ratio of the building are variables related to energy demand and solar panels installed on the building roof and building envelope are variables related to energy generation. This study proceeded as follows; Firstly, the simulation model of large office and elementary school has the same mutual volume and total floor area, and the each floor area and number of floors are adjusted so that the S/V ratio is different. To the next, the energy demand and energy generation of the simulation model were derived based on the meteorological data of Seoul, Daejeon, Busan. Finally, energy demand, energy generation, and final energy demand were compared with heat transfer rate, S/V ratio, building type, region, and orientation. The results of this study is that consideration of solar power generation in terms of energy generation should be taken into consideration at the same time in consideration of the heat transfer rate, the shape, the region and the direction of the zero energy building design.

• 한국에너지공학회:학술대회논문집
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• 한국에너지공학회 2007년도 추계학술 발표회
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• pp.136-140
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• 2007

• 전기저널
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• 1호통권73호
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• pp.8-13
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• 1983

• 비파괴검사학회지
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• 제22권2호
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• pp.140-148
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• 2002

중수로 압력관으로 사용되는 Zr-2.5Nb 재료의 고온 이방성 탄성계수를 고온 초음파공명분광법(RUS)로 측정하였다. 소형 가열로 내에 알루미나 waveguide와 광대역 초음파 센서를 사용하여 초음파에너지를 시편에 가하고 시편의 공명주파수를 측정하였다. 압력관의 축 방향, 반경 방향, 원주 방향에 일치하도록 장방형 시편을 가공하였으며 각 방향에 대한 탄성계수 텐서 9개의 값을 상온${\sim}500^{\circ}C$ 온도 구간에서 측정하였다. 탄생계수 텐서, $c_{ij}$는 모두 온도가 증가함에 따라 점진적으로 감소하며 원주 방향의 탄성계수가 축 방향 및 반경 방향의 탄성계수보다 높았다. 이것은 Young's modulus나 shear modulus의 경우에도 일치하였으며 축 방향과 반경 방향의 경우 큰 차이를 나타내지 않았다. 축 방향 및 반경 방향의 비틀림 탄생계수가 $150^{\circ}C$ 부근에서 서로 교차하였으며 이는 단결정 지르코늄의 $c_{44}$ 및 $c_{66}$의 교차 현상과 일치하였다.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2008년도 추계학술대회 논문집
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• pp.625-626
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• 2008

• Journal of Mechanical Science and Technology
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• 제16권8호
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• pp.1064-1071
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• 2002

Stainless steel pipe of type 304 the with a wall thickness of 26.9 mm and the outer diameter 406.4 mm is welded by manual arc welding process. Mechanical properties and fracture toughness of type 304 stainless steel are investigated in the temperature ranging from room temperature to -162$^{\circ}C$ The results obtained are summarized as follows. The tensile strength noticeably increases as the temperature becomes lower while the yield strength is relatively insensitive to temperature. The Charpy impact energy and CTOD values become higher in the case that crack propagation direction is aligned to the transverse axis upon the rolling direction than longitudinal direction. The drop of fracture toughness is associated with the noticeable diminution of plastic component as temperature seduces from room temperature to -162$^{\circ}C$ .