• Korean Journal of Construction Engineering and Management
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• v.13 no.5
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• pp.84-93
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• 2012

Most of the studies on reduction of buildings' environmental burden in the construction industry have been focused on carbon dioxide emission, although there are various kinds of environmental issues such as global warming, acidification, and etc. which are considered by many researchers. Therefore, this study defined and suggested six impact categories and the principles to assess each impact for the assessment of comprehensive environmental impacts of buildings. The six impact categories are abiotic depletion, global warming, ozone layer depletion, acidification, eutrophication, and photochemical oxidation. A case study has been conducted through comparative analysis of two structural design alternatives to confirm the necessity of assessing the six impact categories. That is, the results of global warming potential and the six impacts proposed in this study were compared. By comparing the results of only global warming potential, the second design alternative using 24MPa concrete was chosen as a better alternative, while the first design alternative using 21MPa concrete was resulted as a better alternative when six impact categories were considered. The results mean that the assessment of various environmental impacts is an appropriate and reasonable approach and the comprehensive assessment offers more reliable results of environmental impacts in the building construction.

• Journal of the Korea Concrete Institute
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• v.26 no.4
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• pp.465-474
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• 2014

This is a comparative study that shows the overall environmental impacts from concrete structures when different compressive strength of concrete applied to structural systems having the same reference flow with different durability. A total of 24 MPa, 40 MPa and 60 MPa cases is analyzed to define the characteristic using end-point perspective LCA methodology including the stages of production, construction, maintenance and disposal. As results, global warming, non-renewable energy and respiratory inorganics problems are the major issues for assessing environmental impacts of concrete products.

• Journal of Korean Society of Environmental Engineers
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• v.27 no.7
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• pp.704-711
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• 2005

In this study, life cycle assessment(LCA) for the nuclear power generation system and the thermal power generation system, which make a great distribution of the electric power supply in Korea, has been carried out to compare the environmental impact between two power generation systems. In system boundary of this study, the stage of construction, operation and demolition & disposal were included. For life cycle impact assessment(LCIA), three cases were considered; the single environmental impact for the $CO_2$ emissions, the 8 major global environmental impact, and the major global environmental impact categories including radioactive impact. As the results, it was found that the nuclear power generation system is environmentally superior to the thermal power generation system as 10,000 times in the evaluation for the $CO_2$ emissions, 90 times in the evaluation for the 8 major environmental impact categories, and 40 times in the evaluation for the environmental impact categories including radioactive impact.

• Clean Technology
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• v.15 no.3
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• pp.224-230
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• 2009

Life Cycle Assessment (LCA) has been studied on the reuse of glass bottles. The system boundary in this study encompassed from gate to gate such as production and transportation. A 360 mL volume of a glass bottle was selected as the functional unit. The environmental impact assessments was studied on 6 categories including abiotic resource depletion, acidification, eutrophication, global warming, ozone depletion, and photochemical oxidant creation. The results showed that the most significant impact categories were abiotic resource depletion (48.63%) and global warming (46.27%), and the rest categories revealed insignificant impacts. In the whole system, the chemicals used for the new bottle production revealed the major contribution to the environmental impacts (71.24%), followed by the use of electricity (16.74%) and transportation (11.8%). In addition, the environmental impact of sodium silicate to be put into the stage of the new bottle production was found to be 45.68%, causing severe influence on abiotic resource depletion and global warming.

• Proceedings of the Korean Information Science Society Conference
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• 2001.04b
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• pp.364-366
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• 2001

문서 범주화는 전자 정보환경에서 매우 유용한 정보처리 도구로서, 다양한 문서 범주화 기법 및 성능향상을 위한 연구들이 지속적으로 이루어지고 있다. 그러나, 대부분의 연구들은 문서 범주화의 대상이 되는 단어 자질 공간의 차원축소 문제에만 집중되었을 뿐, 학습단계에 큰 영향을 미치는 다범주 단어 자질의 범주 모호성은 고려하지 않았다. 본 연구에서는, 다범주 자질의 범주 모호성을 해소함으로써 문서 범주화의 성능향상을 유도하는 범주 모호성 해소 가중치 W를 제시하고 이를 실험을 통해 증명하였다. 실험에서는 Naive Bayes 분류기와 가중치 W를 적용한 Naive Bayes-W 분류기를 직접 구축하여 문서 범주화의 성능향상 여부를 비교하는데 사용하였다. 도출된 실험결과를 통해, 가중치 W는 현재의 분류기가 가지고 있는 자질 표현의 범주 모호성이라는 단점을 보완하고 분류기의 성능향상을 유도함으로써 정보검색시스템의 검색효율을 높이는 데 활용될 수 있음일 증명되었다.

• Journal of the Korean Society for Railway
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• v.18 no.6
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• pp.558-566
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• 2015

In this study, quantitative environmental impact assessments of the VSL anchor and RB(Reaming and Bearing) anchor systems were conducted after a life-cycle assessment (LCA). In addition, improvements which reduce the adverse environmental effects of the RB anchor system were confirmed through comparisons with results with a VSL anchor system. Both results showed that water ecotoxicity and global warming are the most important in environmental influences. To determine the effect of reducing the RB anchor system environment, the result was normalized for the environmental impact category. Most items appeared to have been improved with regard to the RB anchor system. The most significant improvement was a 77% decrease in POC levels(photochemical oxidant creation). Greenhouse gas emissions, related to global warming, were decreased by 44%. It is expected that these quantitative environmental impact assessment results will serve as the basis of an anchor system for civil engineering and environmental impact assessments.

• Journal of the Korea Organic Resources Recycling Association
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• v.11 no.1
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• pp.77-83
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• 2003

본 연구는 폐플라스틱 재활용의 합리적인 방안을 제시하기 위한 기초자료로서 재활용방법(물질재활용, 에너지 회수, 화학적재활용)에 대한 주요 환경인자를 규명하며, 이를 토대로 전과정평가 도구(tool)인 시마프로 5.0을 이용하여 폐플라스틱의 재활용 방법별 환경성을 비교하였다. 폐플라스틱의 재생원료화 전 공정에 투입되는 투입산출물로 인한 환경부하(Original Impact)와 재생원료의 신재 대체를 고려한 환경부하 삭감효과(Avoided Impact)를 합한 최종 영향 평가를 토대로 재활용방법별 환경성을 비교하여 환경영향범주에 대하여 비교 평가하였다. 그 결과 폐플라스틱 재활용방법에 대한 각 영향범주별 주요 영향 요인은 지구온난화로 나타났다. 또한, 지구온난화에 대한 영향은 물질재활용, RDF공정 및 용기형 폐플라스틱 고로원료화공정이 음(-)의 값으로 환경삭감효과가 크게 나타났으며, 오존층 파괴에 대한 영향은 유화 공정이 환경부하가 가장 크게 나타났다. 산성화, 부영양화 및 광화학산화물 생성에 대한 영향은 용기형 고로원료화와 RDF공정이 환경부하삭감효과가 큰 것으로 나타났다.

• Journal of Korean Society of Environmental Engineers
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• v.39 no.12
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• pp.698-705
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• 2017

Environmental impact of a mobile phone charger containing recycled plastic was quantified using LCA and the environmental benefits from the use of recycled and virgin plastic were compared. The assessment considers potential environmental impacts across the whole life cycle of the charger including; pre-manufacturing; manufacturing; distribution; product use; and end-of-life stages and quantified six environmental impact categories; Abiotic depletion; Acidification; Eutrophication; Global warming; Ozone layer depletion; and Photochemical oxidants creation. The study showed that the environmental impacts of the use stage accounted for 94.4% and 70% in the resource depletion and global warming impact categories, respectively, and the environmental impacts of the pre - manufacturing stage accounted for more than 98% in the other impact categories. The main cause of the environmental impacts in the use stage was electricity consumed by the charger. The main cause in the pre-manufacturing stage was PBA (Printed Board Assembly) and external case manufacturing. In order to quantify the environmental benefits of recycled PC (Polycarbonate) in the exterior case, the environmental impacts of 1 kg production of recycled PC and virgin PC were evaluated. The environmental impact on the abiotic depletion of the recycled PC is estimated to be 30% compared to the virgin PC, and the impacts on the other impact categories of the recycled PC were less than 5% of the virgin plastic. Sensitivity analysis was performed for 12 items including site data and assumptions made. The sensitivity of each item was less than 10%. The results of this study confirm that designing compact and light PBA, improving charging efficiency, and use of recycled plastic are important design factors to reduce the environmental impact of a charger.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.38 no.6
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• pp.851-857
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• 2018

In this research, LCA analysis of the manufacturing process of pot bearing for fixed, movable in all directions, movable in one direction was carried out to analyze the environmental load using the LCA methodology. Especially, the water footprint that has been and issue in recent years was analyzed. As a result of LCA, it was analyzed that the contribution of the plate was more than 64.2% in all of the six impact categories in the case of fixed pot bearing base, and more than 94% in the category of resource depletion and photochemical oxidant creation. In the case of all direction pot bearing and one direction pot bearing, the contribution of PTFE was the highest in the global warming and stratospheric ozone depletion, and the contribution by the plate was higher in the other impact categories. The water footprint of each type of pot bearing was analyzed as $22.4m^3\;H_2O\;eq/kg$ for one direction pot bearing, $17.1m^3\;H_2O\;eq/kg$ for fixed pot bearing, and $14.1m^3\;H_2O\;eq/kg$ for all direction pot bearing. As a result of life cycle analysis, the contribution of water use in manufacturing was more than 65% in all three types. The results of this study can be used as basic data for decision making in construction method and material selection of bridges in the future.

• Journal of Korean Society of Environmental Engineers
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• v.32 no.5
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• pp.499-508
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• 2010

This study proposed a life cycle impact assessment index that can indicate the environment-related information of the product in monetary value such that the national geographical, environmental, and social features are fully reflected based on a damage-oriented model. First, the estimation process was classified into characterization, damage assessment, and integration stages considering the six biggest impact categories: resource depletion, global warming, ozone depletion, acidification, eutrophication, and photochemical oxidant creation. Moreover, this study came up with the 16 category endpoints related to the 6 impact categories, and the damage function, to the 4 largest safeguard subjects. The integration indices of finally identified impact categories were KRW 21.8/kg Sb, KRW 6.19/kg$CO_2$, KRW 53,000/kg CFC-11, KRW 13,100/kg $SO_2$, KRW 2,310/kg ${PO_4}^{3-}$, and KRW 3,030/kg $C_2H_4$. Using the results of this research, environmental impacts based on the environmental load generated throughout the entire life cycle of a product can serve as a single index in monetary value; thus enhancing understanding and utilization of the results of life cycle impact assessments.