• Journal of the Korea Concrete Institute
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• v.22 no.6
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• pp.787-796
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• 2010

The main reason of the earth global warming is $CO_2$ and the regulation about it in the whole world has been reinforced to reduce $CO_2$ emission. It is needed that we should reduce it in the process at the production of concrete generated much of $CO_2$ emission as the primary material of construction industry recognized unfriendly environment industry. Based on a concrete, this study was constructed the system to evaluate $CO_2$ emission generated in the stage of material production, transportation, manufacture and developed the program to reduce and evaluate it efficiently. As a result, most of $CO_2$ emission is generated in the stage of material and it is quantitatively evaluated $CO_2$ emission generated in the stage of materials, transportation and manufacture. Moreover, the evaluation system of the volume of $CO_2$ emission which has the friendly environment technology about reduction of $CO_2$ emission at each stage is suggested for quantitatively evaluation $CO_2$ emission generated in the process at the production of concrete and remicon production company could use it to evaluation $CO_2$ emission.

• Korean Journal of Construction Engineering and Management
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• v.8 no.6
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• pp.150-158
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• 2007

As the amount of $CO_2$ emission in Korea is ranked 9th and the increasing rate of $CO_2$ emissions highest in the world, it is strongly necessary to devise methods to decrease the amount of $CO_2$ in each industry as the basis of establishing environmentally sustainable production system. This paper aims to identify the characteristics of $CO_2$ emissions from construction wastes throughout the simplified LCA (Life Cycle Assessment) and suggest the strategic guideline for the construction waste management plan to decrease $CO_2$. As a result of LCA on the case of a high-rise residential building project, total sum of $CO_2$ emission generated from construction wastes appeared as 6,818,123kg-$CO_2$ and $CO_2$ emission per unit floor area as 21.01kg-$CO_2/{\beta}{\ge}$. The principal waste materials generating more than 95% of $CO_2$ are materials such as reinforcing bar, temporary materials, cement, ready-mixed-concrete, concrete products, and tile, which have relatively high unit emission rate of $CO_2$ in the process of production. Besides, more than 92% of $CO_2$ was generated from the activities such as structure work, plaster work, temporary work, and tile and stone work, which are generally executed in the early phase of the whole construction period. Reflecting these results, the guideline for the construction waste management plan was recommended. If the waste management plan is established considering the guideline suggested, there would be high potential to decrease the amount of $CO_2$ generated from construction wastes.

• Korean Journal of Construction Engineering and Management
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• v.17 no.3
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• pp.52-60
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• 2016

This study investigates and analyzes the total amount of energy consumption and $CO_2$ emission during the material manufacturing, transportation, construction, operation, and disposal phases of eight elementary school buildings in South Korea. Toward this ends, the hybrid LCA model is proposed. The life cycle energy consumption and $CO_2$ emission of eight case buildings are assessed using the hybrid LCA model with an assumption that the operation period is 40 years. As a result, the embodied(sum of the energy consumption in the material manufacturing, transportation and construction phases), operational and disposal energy were 2,279, 11,182, $228Mcal/m^2$, respectively, on average. The average embodied, operational, and disposal $CO_2$ emission were 604, 2,708, 60 kg-$CO_2/m^2$, respectively, on average. This result indicates that about 17% of life cycle energy (or $CO_2$ emission) is consumed in the material manufacturing, transportation and construction phases. Thus, it is necessary to consider the embodied energy and $CO_2$ emission to reduce the life cycle energy and $CO_2$ emission of school buildings. In addition, while the insulation standard of building have been provided based on the climate zone, energy consumption in operation phase still varied depending on the regions in this study. Thus, the insulation standard of building needs to be improved through considering the climate of regions in detail.

• Korean Journal of Soil Science and Fertilizer
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• v.43 no.6
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• pp.911-916
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• 2010

Rice paddy fields and crop residue burning are a major source of methane ($CH_4$) emissions, a potent greenhouse in agriculture. This study was conducted to assess $CH_4$ emissions in Korea cropland sector from 1990 to 2008. Greenhouse gas emissions from the cropland sector are calculated in two categories: 4C (Rice cultivation) and 4F (Field burning). In 4C: Rice Cultivation, methane emissions from paddy fields (continuously flooded and intermittently flooded) cultivated for rice production had decreased from 395 $CH_4$ $10^3$ Mg in 1990 to 297 $CH_4$ $10^3$ Mg in 2008. $CH_4$ emissions converted into $CO_2$ equivalent were 8,303 $CO_2$-eq. $10^3$ Mg in 1990 and 6,229 $CO_2$-eq. $10^3$ Mg in 2008. Greenhouse gas emissions from paddy field in Korea showed that it was gradually going down as the cultivation area decreased. In 4F: Field Burning, methane emissions by burning crop residue increased from 2,502 $CH_4$ Mg in 1990 to 2,726 $CH_4$ Mg in 2008. Emissions converted $CH_4$ into $CO_2$ equivalent were 53 $CO_2$-eq. $10^3$ Mg in 1990 and 57 $CO_2$-eq. $10^3$ Mg in 2008. Total emissions of $CH_4$ from the cropland sector declined from 8,356 $CO_2$-eq. $10^3$ Mg in 1990 to 6,287 $CO_2$-eq. $10^3$ Mg in 2008.

• The Journal of the Korea Contents Association
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• v.14 no.12
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• pp.999-1009
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• 2014

In this paper, $CO_2$ emission and storage amount are evaluated for real RC (Reinforced Concrete) underground structure considering $CO_2$ amount including material manufacturing, moving, and construction, repairing timing stage regarding extended service life. Four mix proportions with mineral admixtures are prepared and $CO_2$ diffusion coefficient are obtained based on a micro modeling. Referred to carbonation durability limit state, $CO_2$ emission and storage amount are evaluated, which shows higher initial $CO_2$ emission is caused due to larger unit content of cement and the storage increases with more rapid carbonation velocity. Furthermore various $CO_2$ concentration is adopted for simulation of $CO_2$ evaluation including measured $CO_2$ concentration (600ppm). With higher concentration of $CO_2$ outside, carbonation velocity increases. In order to reduce $CO_2$ emission through entire service life, reducing initial $CO_2$ emission through mineral admixture like fly ash is more effective than increasing $CO_2$ storage through OPC since $CO_2$ is significantly emitted under manufacturing OPC and $CO_2$ storage in cover concrete of RC structure is not effective considering initial concrete amount in construction.

• Journal of the Korea Concrete Institute
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• v.21 no.1
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• pp.85-92
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• 2009

A concrete is considered unfriendly-environmental material because it uses cement which emits much $CO_2$ during producing process. However, a concrete absorbs $CO_2$ through carbonation process during service life. In this paper how much concrete absorbs $CO_2$ through carbonation was calculated using 1) concentration of carbonatable substances in concrete, 2) carbonated volume of concrete, 3) molecular weight of $CO_2$ based on references and the method was proposed. $CO_2$ emission from producing $1m^3$ concrete was calculated based on $CO_2$ emission datum of materials used in concrete. From using these methods that calculate $CO_2$ emission and absorption of concrete, assessment of $CO_2$ emission-absorption against a real apartment was conducted by subtracting absorption $CO_2$ according to service life from $CO_2$ emission in the process of making concrete. As a result, a ratio of absorption over emission of $CO_2$ through concrete carbonation according to service life 40, 60, 80 years was assessed about 3.65, 4.47, 5.18%. An objective of this study is to propose how to calculate emission - absorption of $CO_2$ from producing and using concrete. Although the result value, emission - absorption of $CO_2$, is 5.18% very low when the service life of an apartment is 80years, the value can be improved by reducing emission from using blended cement such as blast furnace slag or increasing replacement ratio of cement and increasing carbonated volume of concrete from expanding service life of a building. This study may be useful when $CO_2$ emission - absorption of concrete is evaluated in the further study.

• Proceedings of the Korean Society of Disaster Information Conference
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• 2015.11a
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• pp.201-202
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• 2015

과거 연료소모량과 오염물질 배출량을 추정하기 위한 연구에서는 주로 속도변수를 이용하였으나, 속도의 변화에 따른 연료소모량 및 오염물질 배출량의 변화를 올바르게 반영하지 못하는 문제점이 대두되었다. 이러한 문제점을 극복할 수 있는 대안으로 평가받는 것이 가속도이다. 이처럼 가속도 변수가 중요하게 다루어지고 있으나 여전히 연료소모량이나 오염물질 배출량과 관련하여 급가속을 판단할 만한 기준이 모호하다. 이에 본 연구에서는 연료소모 및 $CO_2$ 배출량을 증가시켜 급가속으로 판단할 수 있는 가속도 임계치를 추정하고자 하였다. 가속도 임계치 및 모형추정을 위해 LPG 중형 승용차량에 장착한 차량 정보 저장장치로부터 가속 주행실험시 수집한 실시간 데이터를 수집 분석하였다. 가속의 특성상 동일한 가속도라 할지라도 정지상태인지 여부에 따라 동일한 가속도에 대한 연료소모량, $CO_2$ 배출량이 상이하게 나타난다. 따라서 실험을 통해 정지상태에서 가속시 관성을 극복하기 위한 동력이 요구되는 속도의 범위를 확인하고 이중 출발 가속주행시 임계가속도를 도출하였다. 가속 주행실험 결과 연료소모 및 $CO_2$ 배출 증가량이 급격히 증가되는 임계가속도를 도출하기 위해 CART 분석을 이용하였으며, 그 결과 정지 상태에서 가속하는 경우 $2.598m/s^2$, 의 가속도가 연료 및 $CO_2$ 배출량을 크게 증가시키는 임계 가속도인 것으로 추정되었다.

• Journal of Environmental Policy
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• v.12 no.3
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• pp.97-122
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• 2013

The ARDL(Autoregressive Distributed Lag) method is employed analyzes the long-run equilibrium relationships among environmental pollution($CO_2$ emissions) per capita, income levels per capita, and energy consumption per capita. The error correction model is employed to analyze the short-term effects of income and energy consumption on $CO_2$ emissions. The Toda-Yammamoto method is employed for causal analysis among the three variables. The results show that income levels, energy consumption, and $CO_2$ emissions are cointegrated. We found the N type relationship between income and $CO_2$ emissions. Long-term elasticities of income and energy consumption with respect to $CO_2$ emission were greater than their short-term elasticities. There were a bilateral causality between energy consumption and $CO_2$ emissions. There was a unilateral causality from $CO_2$ emissions to income and from energy consumption to income not vice versa. Energy consumption can be an important variable to contribute to forecasting $CO_2$ emissions.

• Korean Journal of Environmental Biology
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• v.35 no.1
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• pp.13-20
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• 2017

Greenhouse gas emission from agricultural land is recognized as an important factor influencing climatic change. In this study, the national $CO_2$ emission was estimated for paddy soils, using soil GHG emission model (DNDC) with $1km^2$ scale. To evaluate the applicability of the model in Korea, verification was carried out based on field measurement data using a closed chamber. The total national $CO_2$ emission in 2015 was estimated at $5,314kt\;CO_2-eq$, with the emission per unit area ranging from $2.2{\sim}10.0t\;CO_2-eq\;ha^{-1}$. Geographically, the emission of Jeju province was particularly high, and the emission from the southern region was generally high. The result of the model verification analysis with the field data collected in this study (n=16) indicates that the relation between the field measurement and the model prediction was statistically similar (RMSE=22.2, ME=0.28, and $r^2=0.53$). More field measurements under various climate conditions, and subsequent model verification with extended data sets, are further required.

• Korean Journal of Construction Engineering and Management
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• v.15 no.4
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• pp.119-127
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• 2014

This study aims to determine whether or not the input output life cycle assessment (I-O LCA) model can be used to assess the carbon dioxide (CO2) emission of buildings in initial planning phase. To ensure this end, this study proposed I-O LCA model which is the simplified LCA model and Hybrid LCA model which is the detailed LCA model, and then assessed and compared the CO2 emission of six case projects (three apartment complexes and three educational facilities) using the two LCA model. The results of the case study showed that the CO2 emissions assessed by the I-O LCA is significantly similar to the CO2 emission assessed by the Hybrid LCA model. The similarity of results from both LCA models was 78.2-86.3% in apartment complexes and 59.9-84.8% in educational facilities. However, the CO2 emissions from I-O LCA model were smaller than the CO2 emissions from Hybrid LCA model in case study. Nevertheless, the case study showed that the I-O LCA model was capable of assessing the CO2 emission of buildings quite appropriately although the I-O LCA model is the simplified LCA model which considers only the construction cost. The I-O LCA model is expected to be a useful tool for assessing the CO2 emission of buildings in initial planning phase.