• Journal of Climate Change Research
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• v.8 no.4
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• pp.377-384
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• 2017

Amid growing concerns about energy security, energy prices, economic competitiveness, and climate change, district heating (DH) system has been recognized for its significant benefits and the part it can play in efficiently meeting society's growing energy demands while reducing environmental impacts. Policy makers often need to quantify the fuel and carbon dioxide ($CO_2$) emissions savings of DH system compared to conventional individual heating (IH) system in order to estimate its actual emissions reductions. The objective of this paper is to calculate energy efficiency and $CO_2$ emissions saving, and to propose the future direction for DH system in Korea. DH system achieved total system efficiencies of 67.9% compared to 54.1% for IH system in 2015. DH system reduced $CO_2$ emissions by $381,311ton-CO_2$ (4.1%) compared to IH system. The results suggest that DH system is more preferred than IH system using natural gas. In Korea, the aim is to reduce dependence on fossil fuels and to use energy more efficiently. DH system have significant potential with regard to achieving this aim, because DH system are already integrated with power generation in the electricity since combined heating and power (CHP) are used for heat supply. Although the future conditions for DH may look promising, the current DH system in Korea must be enhanced in order to handle future competition. Thus, the next DH system must be integrated with multiple renewable energy and waste heat energy sources.

• Environmental and Resource Economics Review
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• v.22 no.1
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• pp.77-98
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• 2013

China, the world's largest $CO_2$ producer, is likely to be obligated to reduce greenhouse gas emissions under the post-Kyoto protocol. This paper estimates a Shephard input distance function for the Chinese fossil-fueled power generation sector to measure the shadow price of $CO_2$ emissions, technical efficiency, and indirect Morishima elasticities of substitution between inputs. Empirical results show that, on average, it costs approximately 3.2 US dollars per year to reduce $CO_2$ emissions by one ton over the period 1981-2009. This finding indicates that Chinese power sector is expected to benefit from selling emission permits to other countries such as Korea and Japan, given that our estimate for China is lower than the ones previous literatures estimated for the power sector in these countries. The maximum attainable average $CO_2$ reduction potential amounts to approximately 25 million tons per year by improving technical efficiency. Capital is substitutable with both coal and oil and capital is relatively more readily substituted for these fuels.

• Journal of Animal Science and Technology
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• v.62 no.1
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• pp.64-73
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• 2020

Producing animal products from farm to table emits massive amounts of greenhouse gases (GHGs). Modified meal plans, mainly including vegetables and grains, have been recommended to reduce GHG emissions. However, these meal plans have not been developed with regard to the micronutrient content, but rather with regard to the energy requirements of grains and vegetables, which could result in a nutritional imbalance. For this reason, we investigated a common Korean suggested meal plan (SMP) from the National Institute of Agricultural Sciences, in which nutritional conditions were considered, and evaluated its GHG emissions using the Life Cycle Assessment Inventory Database and nutritional values. The SMP, which included meat, was based on the Korean Nutrition Society for adult men age 19 to 29, and was changed to a vegan meal plan (VMP). Animal-based protein sources were substituted for meat alternatives, such as beans and tofu, for which carbon footprint data was available. To compare the nutritional differences, the 9^th Korean Food Composition Tables I and II were consulted. To calculate GHG emissions, the carbon footprint data of the food was converted to a CO₂ equivalent (CO₂e) using a procedure from the Foundation of Agriculture Technology Commercialization and Transfer. It was found that GHG emissions per calorie were 18% lower for the VMP when compared to the SMP. However, if GHG emissions per total amino acids were evaluated, the VMP GHG emissions per total amino acids were 0.12 g CO₂e/mg, while the corresponding value for the SMP was 0.06 g CO₂e/mg. The Korean daily meat intake reported by the Korea Agricultural Statistics Service was 37.1% lower than in the SMP, but when converted to a protein intake the figure was 17.0% lower. It was found that each SMP resulted in more GHG emissions than the VMP, but when considered as GHG emissions per total amino acids, the opposite pattern was apparent. There is a need to conduct more detailed studies of the variation in GHG emissions with different meal plans, using the daily meat intake per person.

• Korean Journal of Soil Science and Fertilizer
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• v.44 no.6
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• pp.1214-1219
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• 2011

This study was conducted to compare of greenhouse gas emissions between 1996 and 2006 IPCC (Intergovernmental Panel on Climate Change) guidelines change. Greenhouse gas emissions were calculated separately by rice cultivation, agricultural soils and field burning of agricultural residues from 2000 to 2008 according to 1996 and 2006 IPCC guidelines. To calculate greenhouse gas emissions, emission factor and activity data were used IPCC default value and the food, agricultural, forestry and fisheries statistical yearbook of MIFAFF (Ministry for Food, Agriculture, Forestry, and Fisheries). The greenhouse emissions by 1996 IPCC guidelines were highest in rice cultivation as 4,008 $CO_2$-eq Gg of 2000 and 3,558 $CO_2$-eq Gg of 2008. The emissions by N-fixing crops, crop residues returned soils and field burning did not much affect the total emissions. $CO_2$ emissions by urea and lime were calculated by adding in 2006 IPCC guidelines and its emissions were 157 and 82 $CO_2$-eq Gg in 2008 respectively. The emissions by N-fixing crops, crop residues returned to soils and field burning, in common with 1996 IPCC guidelines, did not have a significant impact on total emissions. The total emissions in agronomic sector was decreased continuously from 2000 to 2008 and annual emissions by 2006 IPCC guidelines were approximately 26-29% less than the 1996 IPCC guidelines.

• Journal of Animal Environmental Science
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• v.17 no.sup
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• pp.1-6
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• 2011

Korean Government announced 'The Roadmap to realize a low carbon green society on year 2020' on July 12, 2011 in order to mitigate greenhouse gas (GHG) emissions. Non-energy category of Food, Agriculture, Forestry and Fishery (FAFF) should mitigate 1,349 kilo $CO_2$-equivalent ($CO_2$-eq.) tonnes which is 7.1% of Business-As-Usual on year 2020. The mitigation from animal manure treatment system (AMTS) comprises ca. 45% of the total mitigated amount of Non-energy category of FAFF. Hence, the precise evaluation of GHG emissions from AMTS is important to find effective mitigation measures. Life cycle assessment was used to evaluate GHG emissions from AMTS. The most GHG emitter was a composting/liquid fertilizer/activated sludge system (1,649.45 kg $CO_2$-eq./head/year) and the least GHG emitter was a activated liquid fertilizer system (1,024.46 kg $CO_2$-eq./head/year). Thermophilic oxic process showed the highest ratio (34.9%) of GHG emissions by the use of electricity to total GHG emissions from systems. Energy efficiency should be considered to mitigate GHG emissions from AMTS.

• Journal of Climate Change Research
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• v.7 no.3
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• pp.257-268
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• 2016

Both economic growth and industrial structure have great influence on energy consumption and GHG emissions. This study analyzed long-term scenarios for GHG emissions projections considering economic growth and industry value added change. In consideration of 3 GDP and 3 industry value added outlook, total 9 scenarios were set; 'Assembly Industry Baseline(AI)', 'Assembly KEIT industry(AK)', 'Assembly Advanced Country industry(AA)', 'KDI Industry Baseline(KI)', 'KDI KEIT industry(KK)', 'KDI Advanced Country industry(KA)', 'OECD Industry Baseline(OI)', 'OECD KEIT industry(OK)', and 'OECD Advanced Country industry(OA)' scenarios. In consideration of the GDP increase rate and industry value added outlook, it is estimated that AI scenario's GHG emissions would be 777 million tons of $CO_2eq$ in 2030. On the other hand, in the case of OA scenario, GHG emissions would be 560.2 million tons of $CO_2eq$ in 2030. Differences between AI scenario's and OA scenario's were 216.8 million tons of $CO_2eq$. It can be identified by that GDP and industry value added change have great influence on GHG emissions. In view of the fact that Korea's amount of GHG emission reduction targets in 2030 were 218.6 million tons of $CO_2eq$ that the result of this research could give us valuable insight.

• Journal of Korean Society of Environmental Engineers
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• v.36 no.7
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• pp.506-513
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• 2014

The objective of this study is to establish the greenhouse gases (GHG) inventories and estimate the GHG reduction plans for Daegu University from 2009 to 2011. The annual average of GHG emissions in Daegu University was estimated to be 19,413 ton $CO_2$ eq during the study period. Emissions of electricity usage in Scope 2 most contributed about 55.4% of the total GHG emissions. Also, GHG emissions of Scope 2, Scope 1, and Scope 3 contributed 60.4%, 22.6%, and 17.0%, respectively. In order to estimate reduction potential of GHG, the Long-range Energy Alternatives Planning (LEAP) model was calculated using three scenarios such as sensor installation, LED replacement, and solar facility. The GHG will be reduced by 1,656 ton $CO_2$ eq for LED scenario, by 1,041 ton $CO_2$ eq for sensor scenario, and by 737 ton $CO_2$ eq for solar scenario compared to 2020 business as usual (BAU). Therefore, the total GHG emissions in 2020 apply three scenarios can be reduced by 15% compared with 2020 BAU.

• Journal of the korean Society of Automotive Engineers
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• v.8 no.2
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• pp.31-42
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• 1986

The prediction of performance, exhaust emissions and EGR effect is made by the SI engine cycle simulation. In this simulation several models are employed - two zome, thermodynamic combustion, mass fraction burned, heat transfer, chemical equilibrium, chemical kinetics for NOx, laminar flame speed for ignition delay. The chemical species in burned gas considered are 13 species-CO$_{2}$, CO, $O_{2}$, H$_{2}$O, H$_{2}$,OH, H, O, N$_{2}$, NO$_{2}$, N, Ar - and the cylinder pressure, burned and unburned zone temperature and composition of gas are calculated at each crank angle through the compression, ignition delay, combustion and expansion process. To check the validity of the model, experimental study is done for measuring emissions, combustion pressure and engine output. The predicted values for pressure and emissions show qualitative agreement with the measured data and the EGR effect also shows similar tendency.

• Journal of the Korean Recycled Construction Resources Institute
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• v.3 no.2
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• pp.115-121
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• 2015

The objective of this study is to present the design approach of low $CO_2$ concrete structures for reduction of $CO_2$ emissions. The design approach was implemented considering the system boundary for each processing presented in the ISO 13315-2. As for life-cycle inventory(LCI) for $CO_2$ assessment of concrete structures, data provided from domestic LCI DB was used. Based on the process presented in this study, case studies on the life-cycle $CO_2$ assessment of shear wall concrete structure was conducted. As substitution level of GGBS is 25%, the amount of $CO_2$ emissions and $CO_2$ uptake by concrete carbonation was decreased in the material, demolition and crushing, and transport phase. The amount of $CO_2$ emissions of column and total member was decreased by 26% and 22% respectively, compared to that of OPC.

• Journal of Climate Change Research
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• v.7 no.4
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• pp.443-450
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• 2016

The major greenhouse gases (GHGs) in agricultural sector are methane ($CH_4$), nitrous oxide ($N_2O$), carbon dioxide ($CO_2$). GHGs emissions are estimated by pertinent source category in a guideline book from Intergovernmental Panel on Climate Change (IPCC) such as methane from rice paddy, nitrous oxide from agricultural soil and crop residue burning. The methods for estimation GHGs emissions in agricultural sector are based on 1996 and 2006 IPCC guideline, 2000 and 2003 Good Practice Guidance. In general, GHG emissions were calculated by multiplying the activity data by emission factor. The total GHGs emission is $10,863Gg\;CO_2-eq$. from crop cultivation in agricultural sector in 2013. The emission is divided by the ratio of greenhouse gases that methane and nitrous oxide are 64% and 34%, respectively. Each gas emission according to the source categories is $7,000Gg\;CO_2-eq$. from rice paddy field, $3,897Gg\;CO_2-eq$. from agricultural soil, and $21Gg\;CO_2-eq$. from field burning, respectively. The GHGs emission in agricultural sector had been gradually decreased from 1990 to 2013 because of the reduction of cultivation. In order to compare with indirect emissions from agricultural soil, each emission was calculated using IPCC default factors (D) and country specific emission factors (CS). Nitrous oxide emission by CS applied in indirect emission, as nitrogen leaching and run off, was lower about 50% than that by D.