• 한국신재생에너지학회:학술대회논문집
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• 2010.06a
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• pp.153-153
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• 2010

The world is moving towards a post-carbon society and needs clean and renewable energy for sustainable development. There are many methodological approaches which are helping this shift based on analyzed data about energy resources and which focus on limited types of energy including liquid fossil, solid fossil, gaseous fossil, and biomass (e.g. IPCC Guidelines, ISO 14064-1, WRI Protocol, etc.). We should also consider environmental impact (e.g. greenhouse gas emissions, water use, etc.) and the economic cost of the renewable energy to make a better decision. Recently, researchers have addressed the environmental impact of new technologies which include photovoltaics, wind turbines, hydroelectric power, and biofuel. In this work, we analyze the environmental impact with a carbon emission factor to present a correlation between $CO_2$ emission and the cost of energy resources standardized by the energy output. In addition, we reviewed Life Cycle Assessment (LCA) as another methodology. Researchers who are studying energy systems have ignored the impacts of entire energy systems, e.g. the extraction and processing of fossil fuels. In power sector, the assessment should include extraction, processing, and transportation of fuels, building of power plants, production of electricity, and waste disposal. Therefore LCA could be more suitable tool for energy cost and environmental impact estimation.

• Journal of The Korean Association For Science Education
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• v.37 no.1
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• pp.113-123
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• 2017

The purpose of this study is to investigate engineering students' attitude toward convergence and relevance with engineering education accreditation, gender, and academic year and attitude toward convergence. To be specific, fist, we examined whether the instrument for measuring attitudes toward convergence were reliable and valid for engineering students. Second, we compared levels of attitudes toward convergence in terms of engineering education accreditation, gender and academic year. Third, latent classes, which were distinguished in terms of attitudes toward convergence, were identified. Participants were 2076 engineering students. By using factor analysis and Rasch analysis, validity and reliability of instrument measuring attitudes toward convergence were confirmed. The differences in attitude toward convergence in terms of engineering education accreditation experience, gender, and academic year were examined by independent t-test and ANOVA. There were significant differences in attitude towards convergence in terms of engineering education accreditation, gender, and academic year. Students who experience engineering education accreditation program and male and high academic year have higher levels of attitude toward convergence than others. Lastly latent class analysis (LCA) was conducted to identify subgroups underlying engineering students in terms of attitude toward convergence and five latent classes were identified. In addition, the chi-square results showed that there were significant relationships between identified latent classes and engineering education accreditation, gender, and academic year. Based on these results, engineering education considering students' characteristics and diversity in attitude toward convergence were discussed.

• Journal of Science Education
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• v.41 no.1
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• pp.16-35
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• 2017

This study attempted to investigate the relationship among engineering students' creativity, engineering education accreditation, gender, and academic year. To be specific, fist, we examined the validity and reliability of the instrument for measuring engineering students' creativity by conducting Rasch analysis. Second, we compared level of creativity in terms of gender, academic year, and engineering education accreditation by using three-way ANOVA. Third, correlations among four constructs of creativity were examined. Fourth, latent classes with respect to creativity within the participants were identified using polytomous latent class analysis (poLCA). Data were collected from 2098 engineering students by using instrument for measuring four different constructs (creative cognition, creative tendency, collaboration, environment). By using Rasch analysis, validity and reliability of instrument for measuring creativity were confirmed. And the results of three-way ANOVA showed that there were significant difference in creativity in terms of gender. Female students showed the low level of creativity compared with male students. Also there were significant difference in creativity except creative cognition factor in terms of academic year. But there were no significant difference in creativity between students who participated engineering education accreditation program and the others. All constructs of creativity were significantly correlated with each others. Lastly, poLCA results showed that there were three distinct subgroups within engineering students in terms of the level of creativity. In the subgroup with low creativity, there were more female and first year students. Based on these findings, we discussed education for engineering students' creativity.

• Proceedings of the Safety Management and Science Conference
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• 2012.11a
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• pp.499-506
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• 2012

본 연구는 통계청(2009-2010)의 국가 산업 표준을 기본으로 생애주기를 고려한다. 생애주기에 대한 변수는 경제활동인구와 사업체 동향을 분석하여 실시하며 이에 따른 자격은 산업과 직업에 관련하여 해당하는 자격의 매칭 테이블을 기준으로 그 자격의 가치를 평가하는 방법을 선택하였다. 산업에 대한 분석은 일반적으로 활용되고 있는 경영기법에 따라 그 절차를 수용하고 관련변수를 응용 또는 적용하도록 하였다.

• Proceedings of the Korea Society for Energy Engineering kosee Conference
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• 1998.10a
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• pp.35-40
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• 1998

지구온난화에 영향을 미치는 온실효과 가스 배출을 저감해야 하는 세계적 규범 하에서 전력분야에서는 오염원의 배출 저감기술 개발에 노력해야 한다. 이러한 노력에 못지 않게 중요한 것은 배출원인과 양을 정확히 측정할 수 있는 능력의 배양이라 할 수 있다. 본 연구는 전력의 환경영향 정도의 평가에 있어 수명주기분석의 유용성을 인식하여 이에 따른 개념소개와 도입의 필요성을 피력하고, 이를 발전소의 전원별 환경영향 평가에 유용하게 적용할 수 있음을 사례분석을 통해 간략히 검증하였다.

• Transactions of the Korean hydrogen and new energy society
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• v.28 no.2
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• pp.156-165
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• 2017

This study quantitatively assessed the environmental impacts of fuel cell (FC) systems by performing life cycle assessment (LCA) and analyzed their energy efficiencies based on energy return on investment (EROI) and electrical energy stored on investment (ESOI). Molten carbonate fuel cell (MCFC) system and polymer electrolyte membrane fuel cell (PEMFC) system were selected as the fuel cell systems. Five different paths to produce hydrogen ($H_2$) as fuel such as natural gas steam reforming (NGSR), centralized naptha SR (NSR(C)), NSR station (NSR(S)), liquified petroleum gas SR (LPGSR), water electrolysis (WE) were each applied to the FCs. The environmental impacts and the energy efficiencies of the FCs were compared with rechargeable batteries such as $LiFePO_4$ (LFP) and Nickel-metal hydride (Ni-MH). The LCA results show that MCFC_NSR(C) and PEMFC_NSR(C) have the lowest global warming potential (GWP) with 6.23E-02 kg $CO_2$ eq./MJ electricity and 6.84E-02 kg $CO_2$ eq./MJ electricity, respectively. For the impact category of abiotic resource depletion potential (ADP), MCFC_NGSR(S) and PEMFC_NGSR(S) show the lowest impacts of 7.42E-01 g Sb eq./MJ electricity and 7.19E-01 g Sb eq./MJ electricity, respectively. And, the energy efficiencies of the FCs are higher than those of the rechargeable batteries except for the case of hydrogen produced by WE.

• Journal of the Korea Organic Resources Recycling Association
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• v.14 no.2
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• pp.101-111
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• 2006

In the present work, life cycle assessments (LCA) of various waste-plastic recycling methods (material recycling, refused derived fuel (RDF), recycling on furnace, and pyrolytic oil production) were carried out to investigate their impacts on the environment. Six types of impacts were considered. While the impact on global warming was found to be significant, the impact on others were negligible. The impact values on the global warming caused by the material recycling, RDF, and the recycling on furnace were negative, which implied that their impacts could be noticeably reduced when waste-plastic are used as an alternative to newly drawn plastics. The pyrolytic oil production, however, showed positive value, which may be due to the carbon dioxide produced during electric power generation. The pyrolytic oil production had the largest impact on the ozone layer destruction, which was due to ozone depleting substances produced from the process itself. These results can be used as a useful data for the enhancement of waste-plastic recycling.

• Journal of Korea Water Resources Association
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• v.32 no.3
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• pp.291-300
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• 1999

The Snyder's synthetic unit hydrograph method is selected to apply the concept of the fractal dimension by stream order for the practicable rainfall-runoff generation, and fourth types of the Snyder's relation are derived from topographic and observed unit hydrograph data of twenty-nine basins. As a result of the analysis of twenty-nine basins and the verification of two basins, the Snyder's relation which considers the fractal dimension of the stream length and uses calculated unit hydrograph data shows the best result. The concept of the fractal dimension by stream order is applied to the Snyder's synthetic unit hydrograph method. The topographic factors, used in the Snyder's synthetic unit hydrograph method, which have a property of the stream length like $L_{ma}$ (mainstream length) and $L_{ca}$ (length along the mainstream to a point nearest the watershed centroid) were considered. In order to simplify the fractal property of stream length, it is supposed that $L_{ma}$ has not the fractal dimension and the stream length between $L_{ma}$ and ($L_{ma}\;-\;L_{ca}$) has the fractal dimension of 1.027. From the utilization of this supposition, a new Snyder's relation which consider the fractal dimension of the stream length occurred by the map scale used was finally suggested.

• Korean Journal of Construction Engineering and Management
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• v.19 no.6
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• pp.46-54
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• 2018

In the 21st century, the Earth has continued its efforts to reduce carbon emissions to overcome the crisis caused by climate change. The construction industry, which is a representative industry that produces large amounts of the environmental load during construction, should actively reduce the amount of the environmental load. From the planning stage of the construction facility, it is necessary to consider the environmental load such as route selection and structure type selection to reduce the environmental load. However, the environmental load can be estimated based on the input resource amount. However, in the planning stage, it is difficult to accurately calculate the environmental load due to lack of information on the construction amount. The purpose of this study is to select the environmental load factors for IPC girder bridges to be used in the environmental load estimation model in the planning stage. Specific information related to the environmental load was selected from a list of information available in the planning stage, reflecting the Life Cycle Assessment(LCA), correlation, principal components analysis and expert opinion. The list of selected planning stage information is 10 such as span length and bridge extension, and it is expected to be used as a basic data for the future development of environmental load estimation model.

• Resources Recycling
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• v.22 no.4
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• pp.55-61
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• 2013

In this study, eco efficiency analysis is performed to analyze Neodymium (Nd) containing permanent magnet recycling process. Life cycle assessment (LCA) and life cycle costing (LCC) are used to apply eco efficiency analysis. In the environmental aspects, global warming potential (GWP) of 1kg permanent magnet is 1.25E + 00 kg $CO_2$ eq. and abiotic resource depletion potential (ADP) is 1.10E - 02 Sb eq. This recycling process costs about 2130 KWR. Environmental efficiency of GWP is at 6.43 and ADP is at 5.32 when compared with vigin metal. Economic efficiency is at 6.74. This study confirms that Nd containing permanent magnet recycling process is sustainable system because of environmental and economical improvement.