• 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.

• 한국신재생에너지학회:학술대회논문집
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• 2007.06a
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• pp.747-752
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• 2007

경제적 측면에서 본다면 에너지는 생산과 소비에서 매우 큰 비중을 차지함과 동시에 다른 유형의 상품과 대체 가능성이 높지 않다는 점에 그 중요성이 있다. 에너지시장에 대한 정부개입의 필요성은 자원의 고갈전망이 제시되고 두 차례 석유위기가 발발한 1970년대부터 등장하기 시작하였다. 이러한 일련의 인식변화는 에너지부문에 대해 다양한 형태의 정부개입이 시작되는 계기가 되었다. 에너지시스템에서 발견되는 이러한 일련의 시장실패는 정부개입의 정당성을 확고하게 하는 동시에 정책 운영 자체를 복잡하고 어렵하게 하는 요인이 되고 있다. 에너지정책의 운용이 어려운 이유는 에너지부문에서 발생하는 외부효과가 한 종류가 아니라는 점이다. 신재생에너지의 장점과 매력은 이처럼 복잡한 시장실패를 근본적으로 해결할 수 있다는 잠재력에 있다. 하지만 개발노력이 본격화 된지 30년이 넘었음에도 불구하고 2001년 현재 신재생에너지가 IEA 국가의 TPES에서 차지하는 비중은 5.53%에 불과하다. 다양한 장점에도 불구하고 신재생에너지 기술의 개발과 보급이 저조한 가장 큰 이유는 현재의 에너지시장 상황에서 기술의 경제성이 확보되지 않기 때문이다. 신재생에너지의 장점에 대한 강조와 개발의 필요성은 더 이상 정책의 핵심주제가 아니다. 현 시점에서 정책운영의 가장 큰 이슈는 기술개발과 보급에 대한 중장기적인 전략의 수립, 이른바 '정책의 효율성' 이다. 본 논문은 신재생에너지의 이용 전반에 걸쳐 등장하는 다양한 지속가능성 이슈를 살펴보고 국내 여건에 부합하는 기술개발 및 보급방안을 제시하고자 한다.

• Journal of the Korean Recycled Construction Resources Institute
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• v.6 no.2
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• pp.112-118
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• 2011

The recycled asphalt concrete has gotten increasing attention due to the environmental issues. The volume of reclaimed asphalt has increased significantly for last few years because of city remodeling, pavement maintenance, utility excavation, and road widening. Considering the value of reclaimed asphalt, it is rather used for the recycled asphalt concrete than it is used for fill and cover up material instead of soil. This research will be a supplements incomplete issues from existing research results and suggests the quality control guideline for recycled asphalt concrete and upcoming laws. As the first step of research, the trial construction of RAP(Recycled Asphalt Pavement) performed in expressway construction sites. These trial construction sites have been checked every years. And another construction sites studied and selected for more deeper performance check of RAP. For this checks, we used automatic pavement survey equipment and computerized analysis tools. Also, DSR(Dynamic Shear Rheometer) was used for the fatigue life calculation of binder blends(RAP and virgin binder). As a consequence of this research, the application of recycled asphalt provides good enough quality for highway construction. The preceeding literatures reviewed shows that the asphalt rejuvenator are used in many countries but that type of chemical agent are not used in Korea. By using the data of trial construction and mix design in Chongwon-Sangju construction lane, the surface and base courses consisted with the 10% and 30% rap mix asphalt section maintains good performance for up to 7 years. Through the performance check and laboratory tests(DSR), the quality control and mixture's low temperature prevention are the important factor and chemical agent necessary for increasing the fatigue life of RAP binder.

• Journal of the Korean Recycled Construction Resources Institute
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• v.2 no.1
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• pp.120-127
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• 2006

The hammer-milled characteristics of waste wood materials such as lumber, plywood, particleboard(PB), MDF and railroad tic were investigated in this study. The physical and mechanical properties of recycled boards according to types of recycled particle and the mixing ratios were also studied. The hammer-milled, waste wood materials had the dimensional distributions suitable for the core layer panicle. Bending strengths of recycled boards (one layer) were shown in order of plywood, PB(laboratory-fabricated with particles used in the PB factory), lumber, tego film-overlaid plywood, MDF, waste railroad tie, PB(factory-made) and LPL-overlaid PB. Cured resin and creosote containing waste wood contributed to dimensional stability of reconstituted boards. Considering the mixing effects between lumber and plywood with recycled PB particle, lumber particle was contributive to bending strength, MOE and internal bond(IB) strength, whereas plywood particle was contributive to dimensional stability. The bending and IB strength of 3 layer boards composing only recycled waste wood particles in core layer of board were in order of lumber, plywood, PB and MDF. On the other hand, the thickness swelling was in order of PB, lumber, plywood and MDF. Bending strength of the 3 layer boards mixed with recycled PB-particle in the core layer had a decreasing tendency, as the mixing ratios of recycled PB-particles increased. The dimensional stability of 3 layer recycled board was improved as the mixing ratio of recycled PB-particle increased same as in one layer. Formaldehyde emission of boards fabricated with recycled PB-particles in the core layer of the PB was in the range of E2 grade (below 5.0mg/l).

• Environmental and Resource Economics Review
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• v.18 no.1
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• pp.75-103
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• 2009

The hypothesis suggested by Porter and van der Linde claims that innovating firms operate in a dynamic competitive situation which allows global diffusion of environmental-friendly technologies. Therefore, countries that are subjects to more stringent environmental regulations may become net exporters of environmental technologies. In the context of Porter hypothesis, this study investigates the impact of importing countries' environmental regulation on Korea and Japan's export flows of technologies for renewable energies and energy efficiency by estimating the gravity equation. The estimation result shows that : (1) our results are consistent with the Porter hypothesis where environmental regulation represents a significant source of comparative advantages, (2) Korea's export flows of technologies for renewable energies and energy efficiency with respect to the importing countries' environmental regulation are more sensitive than Japan's, and (3) the adverse relationship between export flows and importers' environmental stringency in developing countries does not hold in the renewable energies and energy efficiency related sector.

• Environmental and Resource Economics Review
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• v.23 no.4
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• pp.747-784
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• 2014

Many countries have implemented a variety of climate and energy policies to reduce greenhouse gas emissions and expand renewable energy production. The ultimate goals of those policies are associated with transition to a low-carbon economy that aims to combat climate change and economic growth. This study aims to examine empirically if the countries which implement overlapping climate policies and renewable energy policies show additional reduction of the GHG emissions than the countries which implement single climate or renewable energy policy. The result shows that overlapping policies contribute to reduce additional GHG but not all cases. In particular, only overlapping policies mixing 'ETS and RPS(renewable portfolio standards)' and 'Carbon Tax and FIT(Feed-in Tariff)' can lead to additional reduction of GHG emissions.

• Journal of the Korean Recycled Construction Resources Institute
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• v.6 no.3
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• pp.199-206
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• 2018

Due to the advantages of less raw materials and fossil fuel consumption, lower carbon footprint, and the capability of pavement performance improvement, the recycling technology of asphalt is developed and applied for road rehabilitation and construction in the western countries over the past two decades. Cold recycled asphalt mixtures are bituminous materials normally made by mixing recycled aggregate from wasted asphalt with an asphalt emulsion and water at room temperature. This paper aims at investigating the properties of cold recycled asphalt mixture with alkali-activated filler according to wasted asphalt aggregate content. As a result, as the content of wasted asphalt aggregate increased, the marshall stability of cold recycled asphalt mixture decreased and void ratio increased. Also, grading curves for cold recycled asphalt mixture as specified in GR criteria were satisfied in all aggregate mixing conditions regardless of the wasted asphalt aggregate content.

• Resources Recycling
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• v.22 no.4
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• pp.46-54
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• 2013

The produced quantity of waste plastics including waste vinyls was assumed as about 5 million tons per year. The quantity of waste vinyls produced from the waste recycling center among total quantity of waste plastics was estimated as about 1 million tons per year. Most of waste vinyls produced from the waste recycling center were recycled as refuse plastic fuel(RPF) or recycled feedstock material. In this study, the medium material using waste vinyls was made by the melting process of heat medium heating and the tensile strength was analyzed for checking the usable possibility of recycled waste vinyl material by comparing with the existent product. In order to use the medium material for producing the recycled product, it can be considered that the tensile strength of medium material is more than 100 $kgf/cm^2$.

• Environmental and Resource Economics Review
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• v.31 no.2
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• pp.141-163
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• 2022

This paper empirically analyzes the effect of renewable electricity generation on the System Marginal Price (SMP) in Korea. Using an ARX-GARCHX model with hourly data from 2016 to 2020, we evaluate SMP determinants and merit order effects. As a result, we find that solar and wind power, as well as gas price and total load, play a critical role in the SMP. In particular, solar power reduces the SMP level but raises volatility during peak and off-peak periods. This result implies that SMP may fall as renewable electricity generation increases, leading to a decrease in the profitability of existing power plants and investment in renewables. On the other hand, even if the subsidy of renewable energy increases the burden on the SMP, it can be offset by the merit order effect, which lowers the SMP.

• Environmental and Resource Economics Review
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• v.31 no.1
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• pp.51-83
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• 2022

Renewable Portfolio Standards (RPS), one of the most commonly adopted regulation for renewable energy expansion since 2012, has the obvious advantage of inducing competition in power generation source and alleviating the government's financial burden. However, the abuse of credit multipliers and the use of national Renewable Energy Credits (RECs) have resulted in the distortion of RPS as a quantitative control policy. Just as no face value 10 years ago can hold its real value, this paper highlights for the first time that 27.8% of total renewable obligations over the total RPS period were not actually met due to REC inflation and the consequent decline in the value of renewable energy generation. In addition, the distortion of face/real value of REC causes problems in interoperability with other government policies such as RE100 and Emission Trading System.