• Journal of The Korean Association For Science Education
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• v.32 no.4
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• pp.775-788
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• 2012

This study was done at a scientific camp sponsored by Nara Women's University Secondary School, Japan. In this school, $10^{th}$ grade students from 4 East Asian countries: Korea, Japan, Taiwan, and Singapore, participated. We made a research on students' perceptions about nuclear energy. Sample populations include 77 students in total, with 12 Korean, 46 Japanese, 9 Taiwanese and 10 Singaporean students. Overall perceptions comparison about nuclear energy shows average values from the order of highest Korea, Taiwan, Singapore, and to lowest, Japan. We implemented a T-test to identify perception differences about nuclear energy, with one group that include 3 countries (Korea, Taiwan and Singapore) and another group that includes all the Japanese students. T-test results of perceptions about nuclear energy shows students from the 3 countries of Korea, Taiwan and Singapore having higher average than Japanese students. (p<.05). Korean average scores regarding overall perceptions about nuclear energy show as the highest in all 4 East Asian countries and also highest in all subcategories. On the contrary in Japan, they have lower and negative perceptions of nuclear energy. In spite of these facts, perceptions of Japanese students about nuclear energy seem lowest and negative mainly because of the recent Fukushima nuclear power plant disaster, caused by the tsunami and its subsequent damages and fears of radiation leaks, etc. This shows that negative information about future disasters and its resulting damages like the Chernobyl nuclear accident could influence more on people's risk perception than general information like nuclear energy-related technologies or the news that the plant is operating normally, etc. Even if the possibility of this kind of accident is very low, just one accident could bring abnormal risks to technology itself. This strong signal makes negative image and strengthens its perceptions to the people. This could bring a stigma about nuclear energy. This study shows that Government's policy about the highest priority for nuclear energy safety is most important. As long as such perception and decision are fixed, we found that it might not be easy to get changed again because they were already fortified and maintained.

• Journal of the Korea Institute of Building Construction
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• v.23 no.4
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• pp.453-464
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• 2023

This research conducts a comparative analysis of the perceived importance of advancing zero energy building certification from the viewpoints of two major stakeholders - designers and building energy assessors. Both groups prioritized the importance of policy, technology, education, incentives, and promotion respectively. For designers, enhancing energy efficiency standards, developing a skilled energy workforce, and implementing an office registration system emerged as critical factors in invigorating the certification process. The findings suggest potential avenues for the government to formulate realistic strategies for boosting the certification activity.

• Journal of the Korea Organic Resources Recycling Association
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• v.28 no.1
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• pp.15-25
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• 2020

Biogas production potential was experimentally estimated for mono- and co-digestion of cow manure and waste grass. The two organic wastes were mixed at five different ratios (100:0, 75:25, 50:50, 25:75, 0:100) on the volatile solids basis, and were assessed using biochemical methane potential (BMP) test. Thee reaction temperatures, 25℃, 30℃ and 35℃, were applied as well, resulting in 15 different combinations for the test. The results showed that both higher temperature and waste grass mixing ratio resulted in higher methane yield and maximum methane production rate. Based on the experimental results, a theoretical farm- or community-scale (240 or 2400 ㎥) anaerobic digester was designed to evaluate the energy balance associated with mono- and co-digestion of the wastes at different temperatures. Although the energy production increased as the temperature and the waste grass mixing ratio increased, the net energy gain, energy production subtracted by energy consumption for heating and maintenance, was estimated to be the highest at 30℃, followed by at 35℃ and 25℃. Therefore, it is advised that both the experimental methane production and the detailed design parameters must be considered for the optimization of the net energy gain from these wastes.

• Journal of Energy Engineering
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• v.8 no.1
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• pp.181-188
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• 1999

재료의 표면을 pulsed laser로 가열할 때, 유한한 두께를 가지는 반무한 평판의 온도분포를 해석하여 열확산계수, 재료의 두께, 열원의 주기, 그리고 열원의 반경이 온도분포에 미치는 영향을 알아보았다. Pulsed laser에 의하여 가열되는 불투명 고체의 시간에 따른 온도는 전체적으로 증가하지만 열원의 주기와 동일한 주기를 가지고 일정한 온도차를 가지는 전체온도와 평균온도의 차, Tac가 존재한다. 열확산계수가 증가하면 재료 내부로 에너지의 확산이 활발하기 때문에 Tac는 커진다. 재료의 두께가 열확산길이보다 얇은 경우에는 두께변화에 따라서 온도가 민감하게 변하지만, 열확산길이보다 재료의 두께가 두꺼울 때는 두께의 변화에 관계없이 거의 일정한 온도가 나타난다. 열원의 단속주파수가 증가하면 한 주기당 에너지가 작아지므로 Tac의 크기는 작아진다. 열원의 반경이 커지면 단위면적당 에너지가 감소하므로 Tac의 크기는 삼각파, 싸인파, 사각파 순으로 크게 나타난다. 따라서 열원의 파형을 측정하여 이를 적용하는 것이 바람직하다.

• Solar Energy
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• v.12 no.1
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• pp.40-47
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• 1992

The present study has been carried out to investigate various passive solar technologies for the possible application to telecommunications office buildings. HVAC systems utilizing the solar energy are analyzed in this regard to elicit the most feasible design. The proposed design is unique, for it has been devised to promote the working spirit with an efficient space planning as well.

• Journal of Korea Foresty Energy
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• v.25 no.1
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• pp.24-30
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• 2006

This study was conducted to understand the biomass and the energy content of 48-year-old Pinus densiflora stand planted in Mt. Wolak, Jecheon-si, Chungcheongbuk-do, Korea. The total biomass of aboveground was 138.14 ton/ha (87.3 ton/ha from stemwood, 41.43 ton/ha from live brances, and 9.41 ton/ha from leaves). Annual net production (ANP) of aboveground was 10.85 ton/ha/yr, and the ANP of stemwood, live branches, and leaves were 5.3 ton/ha/yr, 2.93 ton/ha/yr, and 2.62 ton/ha/yr, respectively. Energy content of aboveground was 2,981 GJ/ha, and annual energy accumulation was 239 GJ/ha/yr. The leaf area index (LAI) of P. densiflora stand was 6.58.

• Korean Chemical Engineering Research
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• v.46 no.5
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• pp.833-844
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• 2008

Bio-energy offers the opportunity to lessen fossil fuel consumption. Energy derived from solar, wind, hydroelectric, geothermal, and biomass sources are considered renewable. Because most forms of bio-energy are derive deither directly or indirectly from the sun, there is an abundant supply of renewable energy available, unlike fossil fuels. The use of bio-energy also provides environmental, economic and political benefits. Bio-energy can be produced from a marine source such as biomass provides a $CO_2$ neutral, non-polluting form of energy. In this paper, the potential of marine biomass is increasingly discussed, given the size of the resource in that more than three quarters of the surface of planet earth is covered by water.

• Proceedings of the Korea Society for Energy Engineering kosee Conference
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• 1996.10b
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• pp.161-166
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• 1996

화학적 증착장치를 이용하여 크기 305mm$\times$915mm인 대면적 투명전도 유리기판 위에 비정질 실리콘 태양전지를 제작하였다. p층 제조 후 SiH4 세척과 수소 플라즈마 처리를 하여 I층에 도핑가스가 침투하는 것을 억제했으며 p-i 계면에 buffer층을 적용함으로써 소면적 단접합 태양전지에서 개발전압 0.825V, 충실도 0.73, 변환효율 9.5%인 셀을 제작하였다. 또한 a-Si/a-Si 이중접합 태양전지에서는 개방전압 1.50V, 충실도 0.77인 셀을 제작하였다.

• Proceedings of the Korea Society for Industrial Systems Conference
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• 2000.11a
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• pp.353-356
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• 2000

두 물체의 충격운동량-충격 및 탄성파 발생의 순으로 작용하도록 하면 계 내에서 충돌 후 생기는 운동량의 관성 속도와 충돌기간동안 발생하는 탄성파의 충격에너지 전달속도가 다른 경우가 있다. 이것은 충돌기간동안 총 운동량은 보존되나 선 운동량이 비 보존되는 경우가 있어서 충돌기간동안 비 보존된 내부 운동량의 시간 적분만큼 충돌을 가한 질량중심이 이동했다는 의미이다. 충돌기간동안 충격파는 탄성파에 근사시키고 그것은 군속도에 근사시켜 이론적 근거를 만들고 실험에 의해 확인했다. 폐쇄된 계 내에서 내부에너지를 이용하여 특별한 두 물체의 충돌기간동안 비 보존되는 운동량 때문에 질량중심이 이동되는 것에 대해 해석한다.

• Journal of The Korean Society of Agricultural Engineers
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• v.52 no.4
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• pp.27-34
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• 2010

본 연구는 농촌마을을 환경친화적으로 계획하는데 활용할 수 있는 신재생에너지 중에서 태양에너지를 고려한 농촌그린빌리지 디자인에 대한 경제성분석을 목적으로 한다. 이 논문에서는 경제적 측면에서 에너지 수지를 고려하여 세 가지 형태의 연구대상 농촌마을에 대한 분석을 실시하였다. 연구대상 농촌마을들에서 실제로 사용했던 전체 에너지를 태양광 발전으로 대체하기 위한 태양광 발전시스템인 3 kWp의 단위 모듈 (PV 시스템)의 개수들을 마을별로 추정하였다. 경제성 분석에서는 두 개 마을의 순현재가치 (NPV)가 평가기간 25년내에 마이너스 값을 보였으며, 나머지 하나의 마을에서 경제성이 있는 것으로 분석되었다. 정부에서 시설설치 보조금을 60 % 지원해 줄 경우에는 모든 마을에서 25년 내에 경제성이 있는 것으로 평가되었다. 경제성 평가 관련인자들에 대한 민감도 분석을 BC (Benefit/Cost) 비율 변화에 대하여 실시한 결과, 설치비용, 전력판매단가, 할인율, 단가 증가율순으로 높은 변화율을 보였다. 본 연구의 결과는 태양에너지가 에너지 재활용이 가능한 농촌마을을 계획함에 있어서 정부의 적절한 지원정책과 에너지 잠재력이 높은 농촌마을을 선별한다면 매우 효과적인 결과를 얻을 수 있다는 것을 보여준 것으로 판단되었다.