• Proceedings of the Korea Air Pollution Research Association Conference
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• 2003.11a
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• pp.516-517
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• 2003

IPCC 2001 보고서에 따른 최근 연구에 의하면, 20세기에 전 지구적으로 대략 0.4$^{\circ}C$~0.8$^{\circ}C$의 기온이 증가하는 결과를 보여주지만 이 증가경향이 시ㆍ공간적으로 일정하게 나타나는 것은 아니다. 지표기온의 변동성은 자연적인 원인과 인간의 활동에 의한 영향를 받을 수 있다. 한반도 온난화는 온실 기체와 도시화같은 원인에 의해 기온의 증가현상이 나타난다. 국지 혹은 지역적인 기후의 특성은 도시화와 같은 토지 이용도의 변화를 포함한 여러가지 인위적인 요소들에 의해 나타날 수 있다. (중략)

• Proceedings of the Korea Air Pollution Research Association Conference
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• 2001.11a
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• pp.439-440
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• 2001

대기 중의 에어러솔 입자들은 직접적으로는 빛의 산란, 흡수 등 복사 평형에 영향을 미치며, 간접적으로는 구름 응결핵(CCN)으로 작용함으로써 알베도와 구름의 수명에 영향을 미치게 된다. 자연적인 에어러솔은 인위적 활동에 따른 황 화합물, 질소 화합물, 유기물. 매연 그리고 토양 먼지의 증가에 의해 사실상 교란되어 왔다. 인위적인 에어러솔에 의한 복사 강제력(radiative forcing)은 현재 전 지구적 평균이 -0.3~-3.5Wm$^{-2}$ 정도로 추정되며, 이것은 온실 기체에 의한 강제력인 +2.0~+2.8Wm$^{-2}$ 와 비교될 만 하다(IPCC, 1995). (중략)

• Journal of the Korean earth science society
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• v.25 no.6
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• pp.402-408
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• 2004

The purpose of this study is to investigate various conceptions of secondary school earth science teachers on some concepts in secondary school earth science courses; wind in cyclone, western intensification of ocean current, westerly wave, greenhouse effect, ozone layer and atmospheric pressure. The subject is 26 in-service teachers of earth science teachers. The results were analyzed on the view of teaching sources for earth science teachers. The results show that earth science teachers have also various misconceptions on some concepts selected in this study. A number of partial understandings were found that were not enough to apply to teaching concepts. Those misconceptions were related to gradient wind on wind in cyclone and frictional force, related to earth rotation on western intensification of ocean current, related to angular momentum conservation and related to the roles of westerly wave. And misconceptions on greenhouse effect are related to main role of greenhouse effect gases, related to sources of ozone gas and phenomenons by atmospheric pressure. The various understanding types found in this study could be apply to teach the selected concepts in secondary school earth science course.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.2
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• pp.182-188
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• 2020

This study aimed to collect the carbon dioxide generated as a by-product from petrochemicals and liquor factories and use it in a crop breeding greenhouse. This was applied mainly to the storage of dry ice and the supply of carbon dioxide to achieve this target. Dry ice has a strong cooling effect because CO₂ becomes a solid or gas at temperatures and pressures below the triple point, and the solid sublimes at -78.5℃ and atmospheric pressure. The consumption of dry ice according to temperature was 0.983kg/day, 2.358kg/day, 5.102kg/day, and 7.035kg/day when the temperature was 5℃, 10℃, 15℃, and 20℃, respectively, which corresponded to 1,102ppm, 1,481ppm, 1,677ppm, and 1,855ppm. Dry ice consumption in the test greenhouse decreased by approximately 0.9kg/h, and the CO₂ concentration in the greenhouse at 9 a.m., before supplying dry ice increased to 517ppm, 1,519ppm at 10 a.m., 1,651ppm at 11 a.m., and 1,651ppm at 12 p.m., before maintaining this level of activity. Overall, this study attempted to contribute to increasing farm income by deriving the supply conditions through an expansion of the supply of carbon dioxide gas for crops.

• Journal of Korea Water Resources Association
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• v.32 no.6
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• pp.617-625
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• 1999

Global warming has begun since the industrial revolution and it is getting worse recently. Even though the increase of greenhouse gases such as $CO_2$ is thought to be the main cause for global warming, its impact on global climate has not been revealed clearly in rather quantitative manners. However, researches using General Circulation Models(GCMs) has shown the accumulation of greenhouse gases increases the global mean temperature, which in turn impacts on the global water circulation pattern. This changes in global water circulation pattern result in abnormal and more frequent meteorological events such as severe floods and droughts, generally more severe than the normal ones, which are now common around the world and is referred as a indirect proof of global warming. Korean peninsula also cannot be an exception and have had several extremes recently. The main objective of this research is to analyze the impact of global warming on the change of flood and drought frequency. Based on the assumption that now is a point in a continuously changing climate due to global warming, we analyzed the observed daily rainfall data to find out how the increase of annual rainfall amount affects the distribution of daily rainfall. Obviously, the more the annual rainfall depth, the more frequency of much daily rainfall, and vice versa. However, the analysis of the 17 points data of Keum river basin in Korea shows that especially the number of days of under 10mm or over 50mm daily rainfall depth is highly correlated with the amount of annual rainfall depth, not the number of dry days with their correlation coefficients quite high around 0.8 to 0.9.

• Journal of Climate Change Research
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• v.2 no.4
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• pp.309-316
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• 2011

The study evaluated the loss rate of carbon dioxide, which is the prevalent greenhouse gas, according to the method of keeping specimens using standard gases. In order to examine the difference generated by a bag of storing specimens, it checked the loss rate according to concentration and time by making a 2nd set of standard gases in a Tedlar bag and an Aluminium bag. The containers lost gases at a rate of 5% or more after 6 day, and 10% or more after 15 days in both bags. In time, it was confirmed that the loss rate of the Aluminium bag was higher than that of the Tedlar bag. Specifically, there was no significant difference between the two bags after 12 days had passed, but by the 15th day, it was confirmed that the loss in an Aluminium bag was more severe than that in the Tedlar bag. The study went on to check the relations between the humidity in storage and the loss rate. The results showed that there was no significant effect of humidity on the loss rate until 72 hours had passed, when the loss rate in the Tedlar bag with high humidity was about 5% higher than that of the Tedlar bag in dry conditions. This study examined the loss rate of carbon dioxide, a typical greenhouse gas. It is important to note that the loss rate was determined by calculating highly reliable carbon dioxide emission and emission coefficient data, with consideration to the method of keeping specimens.

• Korean Journal of Agricultural and Forest Meteorology
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• v.18 no.4
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• pp.378-388
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• 2016

International societies are currently working together to achieve the Climate-Smart Agriculture (CSA) initiative which aims the triple wins: (1) sustainably increasing agricultural productivity and incomes; (2) adapting and building resilience to climate change; and (3) mitigating greenhouse gases emissions. In terms of its scope and context, CSA follows the '3Nong (三農)' vision cast about 200 years ago by Dasan Jeong Yak-Yong who emphasized the triad of governance, management and monitoring towards comfortable, profitable and noble agriculture. Yet, the CSA provides the practical aims that facilitate the development of holistic indicators for quantitative evaluation and monitoring, on which decision-making support system is based. In this study, we introduce an agent-based model, i.e. Mathematical Programming Multi-Agent Systems (MP-MAS), as a tool for supporting the decision-making toward CSA. We have established the initial version of MP-MAS adapted for domestic use and present the preliminary results from an application to the rice farming case in Haenam, Korea. MP-MAS can support both farmers and policy-makers to consider diverse management options from multiple perspectives. When the modules for system resilience and carbon footprint are added, MP-MAS will serve as a robust tool that fulfills not only CSA but also Dasan's '3Nong' vision of sustainable agricultural-societal systems.

• Journal of Climate Change Research
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• v.4 no.3
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• pp.235-244
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• 2013

Carbon dioxide emission estimation methods consist of four tiers according to the IPCC guideline. In this study, estimated results by tier 3 and tier 4 were compared with the theoretically calculated $CO_2$ emissions based on the mass balance approach for a gas fired power plant between March and May 2011. It was found that the relative differences were upto 17% between the measured emissions by tier 4 and theoretically estimated emissions, while the results of tier 3 were similar to those from theoretically estimated ones. The comparisons suggested the possibility of misestimation due to replacing missing, abnormal, or invalid data in continuous emissions monitoring system. When using only the data without those missing, abnormal, or invalid data, the relative differences decreased somewhat but still showed consistent differences depending on the stack. It is suggested that this differences might be due to the accuracy of the measurement instruments for the tier 4, especially, for the flow rate measurement instrument.

• Membrane Journal
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• v.15 no.2
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• pp.147-156
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• 2005

It is well-known that polyethersulfone (PES) has high $CO_2$ selectivity over $N_2\;(or\;CH_4)$ and excellent pressure resistance of $CO_2$ plasticization among muy commercialized engineering plastics[1-4]. Asymmetric PES hollow fiber membranes for flue gas separation were developed by dry-wet spinning technique. The dope solution consists of PES, NMP and acetone. Water and water/NMP mixtures are used in outer and inner coagulants, respectively. Gas permeation rate (i.e., permeance) and $CO_2/N_2$ selectivity were measured with pure gas, respectively and the micro-structure of hollow fiber membranes was characterized by scanning electron microscopy. The effects of polymer concentration, ratio of NMP to acetone, length of air gap, evaporation condition and silicone coating were investigated on the $CO_2/N_2$ separation properties of the hollow fibers. Optimized PES hollow fiber membranes exhibited high permeance of $25\~50$ GPU and $CO_2/N_2$ selectivity of $30\~40$ at room temperature and have the apparent skin layer thickness of about $0.1\;{\mu}m$. The developed PES hollow fiber membranes, would be a good candidate suitable for the flue gas separation process.

• Proceedings of the Korea Water Resources Association Conference
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• 2019.05a
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• pp.73-73
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• 2019

지구 표면의 약 2%에 해당하는 담수에서 육상계 전체가 흡수하는 탄소의 50%가 배출되며, 이는 토양표면에서 배출되는 탄소량에 비해 더 큰 수치로 전 지구적 탄소순환 해석에 중요한 역할을 한다. 특히, 내륙수역과 대기의 경계면에서 $CO_2$ 이동은 전 지구적 탄소순환의 중요한 구성요소로 평가되고 있다. 호수와 저수지 같은 담수 저류시설은 육상에서 기인한 탄소의 운송 및 처리 역할을 한다. 하지만, 저수지에서 온실가스배출량을 평가할 수 있는 명확한 방법론이 부족하며, 전지구 규모 GHGs배출량에 대한 추정에 대한 불확실성이 상당히 큰 상황이다. 본 연구에서는 몬순기후대에 위치한 인공저수지를 대상으로 보다 신뢰도있는 온실가스 배출량 추정을 위해 $CO_2$ NAF 산정하고, 산정에 영향을 미치는 인자들을 분석 하였다. 분석을 위해 $CO_2$ NAF 산정에 필요한 수리 및 수질 인자들을 2017년부터 2018년까지 수집하고, 기초통계량 및 상관분석을 실시하였다. 또한, 주성분분석(PCA) 및 다중선형회귀모델(MLR)과 랜덤포레스트(RF) 기법을 사용해 변수 중요도를 평가하였으며, $CO_2$ NAF 산정 주요인자인 기체교환 계수를 경험적 모델 3종(Cole and Caraco, Crusius, Vachon), 표면갱신형 모델 4종(Heiskanen, Maclntyre, Read, Soloviev)을 비교, 검토하였다. 조사기간 동안 기체교환계수 산정 결과 Crusius 모델 예측값이 평균 $0.342(0.047{\sim}4.323)cm\;hr^{-1}$으로 검토한 모델중 가장 낮은 평균값을 보였으며, Heiskane 모델이 $2.135(0.337{\sim}5.152)cm\;hr^{-1}$으로 가장 큰 평균값을 보였다. 대상 수체는 연주기로 완전혼합되며 수온성층이 약화되는 시기에 저수지 표층 아래에 축적된 탄소가 표층으로 전달되어 높은 수준의 p$CO_2$를 보이며, 수표면에 큰 난류 강도가 작용하는 기간에 대기중으로 배출(pulse emission) 기작이 나타난다. NAF 산정결과 경험적 모델의 NAF값($-1246.0{\sim}6510.3mg-CO_2m^{-2}day^{-1}$)은 표면갱신형 모델 NAF값($-1436.1{\sim}8485.7mg-CO_2m^{-2}day^{-1}$)보다 낮은 수준을 보였으며, 풍속의 함수만을 이용하는 경험적 모델보다 부력 플럭스와 난류 혼합의 영향을 고려하는 Macintyre, Heiskanen모델이 성층 저수지의 $CO_2$ NAF 산정에 적합한 것으로 나타났다. $CO_2$ NAF 산정의 주요인자로 MLR모델은 Tw, EC, pH, Chla, TOC, Alk, RF모델은 EC, DO, TOC가 중요 변수로 평가되었다. PCA 분석결과, 수온이 낮고 성층이 약화되며 pH가 낮은 상태에서 NAF가 큰 것으로 나타났다.