• 대한교통학회지
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• 제33권5호
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• pp.449-460
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• 2015

현재 교통수요모형 기반의 자동차 배출량 추정 모형에서 교통 활동도 자료는 세부적으로 고려되는 반면, 배출계수는 평균적인 값만 반영되고 있기 때문에 배출량 산정 결과의 정확도를 저하시키는 문제가 있다. 본 연구는 도로유형 및 주행시간대와 무관하게 동일한 배출계수가 적용되는 부분을 개선하기 위해, 도로유형과 주행시간대별 연료소모량 차이에 대한 실증적 분석을 기반으로 각 유형별 배출계수의 보정 지표 제시를 목적으로 한다. 이를 위해, '이동식 차량활동도 모니터링 장비(Portable Activity Monitoring System: PAMS)'를 이용해 도로유형 주행시간대별 실 주행 자료를 수집하였고, 각 유형별 연료소모량을 추정하여 이를 비교하였다. 연구 결과 평균 주행속도가 22.5km/h 일 경우, 도로 유형별 주행차량의 가감속도 변화 등의 차이에 따라 국도에서의 연료소모량(95g/km)은 자동차 전용도로에서(81g/km)보다 약 17.3% 높은 것으로 분석되었고, 첨두시간대의 평균 연료소모량(86.73g/km)은 비첨두시간대(82.84g/km)보다 약 4.7% 높은 것으로 분석되었다. 각 유형별 연료소모량의 차이는 공변량 분석 (ANOCOVA)과 다변량 분산분석 (MANOVA)으로 검증하였으며, 그 결과 "주행속도가 동일할지라도, 도로유형과 주행시간대에 따라 연료소모량의 차이가 있다"는 본 연구가설은 유의한 것으로 나타났다. 마지막으로 연료소모량의 차이를 활용하여 각 유형별 배출계수 보정 지표들을 제안하였다. 본 연구는 기존 차량 중심의 배출계수 연구에서 벗어나, 도로 교통 조건에 따른 배출계수 특성을 분석했다는 점에서 의의가 있으며, 본 연구결과를 활용하여 교통부문의 배출량 추정결과에 대한 신뢰성을 향상시킬 수 있을 것으로 기대한다.

• 한국생산제조학회지
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• 제5권1호
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• pp.43-50
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• 1996

From a manufacturing standpoint it would be desirable to monitor the degradation of drawing die, that is essential for the maintenance of die quality, the evaluation of product integrity and the reducing scrap. Acoustic emission is powerful method in monitoring fine wire drawing process, especially in detecting the die fracture at early stage. Experiments also suggested that acoustic emission sigals contained valuable information regarding the stage of a drawing process such as the surface appearance of products and the condition of lubrication. These informations are AE monitoring techniques a possible tool in monitoring the drawing process operation. In order to approach this, this paper discusses the nature of acoustic emission signal presented which illustrate the effects of wire and die material, lubricants, and drawing speed on the generation and the mean voltage level of acoustic emission signal. From these experimental, results, we understanded controlling factors of acoustic emission generation.

• 설비공학논문집
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• 제15권1호
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• pp.40-49
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• 2003

This study has been conducted to identify and quantify the emissions of Volatile Organic Compounds (VOCs) from a new carpet. The carpet sample consists of polypropylene cushion and latex backing. The VOCs have been sampled on sorbent tubes and analyzed by thermal desorption unit and GC/MSD. For over 240 hours, concentration of VOCs has been measured in a small chamber made of stainless steel. With the measured data, emission factor and mass balance have been considered. The experiments have been conducted in accordance with ASTM D5116-97. The carpet has emitted a variety of VOCs, but in this study, 7 VOCs compounds have been considered： chlorobenzene, ethylbenzene, styrene, isopropylbenzene, bromobenzene, 2-chlorotoluene, and 1,2,3-trimethylbenzene. The results show that the concentrations of VOCs and the emission factors have exponentially decayed from relatively high level to low level with time. The gradients of the concentration of VOCs and emission factors are different for various components. It is found that styrene, 2-chlorotoluene are emitted more than others with higher concentrations.

• 설비공학논문집
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• 제18권2호
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• pp.137-143
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• 2006

This study has been conducted to quantify the emissions of Volatile Organic Compounds (VOCs) in a conference room. The carpet has emitted a variety of VOCs, but in this study, 2 VOCs compounds have been considered: Ethylbenzene and 1, 2, 3-Trimethylbenzene. In this study, a three dimensional numerical analysis has been carried out to investigate the emission and behavior characteristics of Ethylbenzene and 1, 2, 3-Trimethylbenzene emitted from the carpet in the conference room. The mass diffusion coefficient and the initial concentrations of VOCs in the carpet have been obtained from experimental data with non-linear regression. It has been found that the concentrations and emission factors of VOCs have exponentially decayed with time and that the concentration gradients and emission factors of VOCs are different from each other for various components. This study may supply fundamental understandings for the emission and behavior characteristics of VOCs.

• 한국태양에너지학회 논문집
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• 제31권1호
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• pp.100-106
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• 2011

This study proposes a $CO_2$ emission reduction method through correlation analysis of a sample building. First, energy saving factors of heating, cooling, lighting were determined for the correlation analysis and $CO_2$ emission contribution rate of the design parameters have been analyzed. Then optimal combination of each design parameter has been drawn. Heat transfer coefficient of walls and windows, air permeability, windows area ratio, and shading devices were selected as applicable energy saving factors of the sample building. Also computer simulation was conducted using experimental design by Orthogonal Arrays of the statistical method. And the contribution rate was estimated by Analysis of Variance-ANOVA. As a result, the $CO_2$ emission in heating was reduced to 51.9%; in cooling to 16.8%; and in lighting to 2% compared to the existing building. The majority of the reduction was presented by heating energy.

• 농업과학연구
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• 제44권4호
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• pp.463-476
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• 2017

Climate change is considered as the greatest threat to our future and descendants. The Korean government has set a target for 2030 to reduce emission of greenhouse gases (GHGs) by 37% from the business-as-usual levels which are projected to reach 851 million metric tons of $CO_2eq$ (Carbon dioxide equivalent). In Korea, GHGs emission from agriculture account for almost 3.1% of the total of anthropogenic GHGs. The GHGs emitted from agricultural land are largely classified into three types: carbon dioxide ($CO_2$), methane ($CH_4$), and nitrous oxide ($N_2O$). In Korea, rice paddies are one of the largest agricultural $CH_4$ sources. In order to analyze domestic research trends related to $CH_4$ emission from rice paddies, 93 academic publications including peer reviewed journals, books, working papers, reports, etc., published from 1995 to September 2017, were critically reviewed. The results were classified according to the research purposes. $CH_4$ characteristics and assessment were found to account for approximately 65.9% of the research trends, development of $CH_4$ emission factors for 9.5%, $CH_4$ emission reduction technology for 14.8%, and $CH_4$ emission modeling for 6.3%, etc. A number of research related to $CH_4$ emission characteristics and assessment have been studied in recent years, whereas further study on $CH_4$ emission factors are required to determine an accurate country-specific GHG emission from rice paddies. Future research should be directed toward both studies for reducing the release of $CH_4$ from rice paddies to the atmosphere and the understanding of the major controlling factors affecting $CH_4$ emission.

• 한국대기환경학회지
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• 제26권1호
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• pp.48-56
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• 2010

Recently it has reported that the motorcycle is a major source of air pollution in urban area by many studies. But the air pollution emission from motorcycle has been high uncertainty due investigation of a lack of activity data and emission factors in Korea. So in this study, the population of moped and VKT (Vehicle kilometers travelled) of motorcycle are investigated for calculation of the emission from this source categories. As the results, the population of moped is estimated as about 400, 000 and corresponded as 23% of registrated motorcycle which is larger than 50 cc in engine displacement. And it is found that the VKT of moped and motorcycle are investigated as 19.1 km/day and 32.3 km/day. Annual air pollution emission from motorcycle and moped are estimated by investigated VKT and updated emission factors. The nationwide emissions of PM_{10}, CO, $NO_x$, VOC are calculated as 910 ton/yr, 208, 198 ton/yr, 3, 032 ton/yr and 25, 575 ton/yr in 2008. The contribution ratio of CO, VOC emission from these sources are estimated as 29%, 24% in on-road transport sector and it is confirmed that motorcycle and moped are major air pollution sources in urban area.

• Journal of Advanced Marine Engineering and Technology
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• 제36권6호
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• pp.788-793
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• 2012

본 연구는 해군함정에 탑재되어 있는 주 추진 디젤엔진에서 배출되는 입자상 물질, 황산화물, 이산화탄소 및 질소산화물의 배출량 예측에 초점을 두었다. 국제사회 및 각국의 정부는 인간의 건강 및 환경을 보호하기 위해 선박의 배기가스 규제를 엄격히 적용하고 있으며 선박 제작사들은 이러한 법규에 대응하기 위해 다양한 기술을 선박에 적용시키고 있다. 엄격히 적용되는 배기가스 법규는 선박의 크기에 따라 차이를 보이고 있지만 함정은 규제대상에서 제외된다. 다양한 연구결과에 의해 선박의 배기가스 배출량 계수(emission factor)는 지속적으로 최신화되고 있으나 함정의 배출량 계수는 그 특성의 차이 때문에 설정이 어려운 실정이다. 본 논문은 함정 엔진의 연료소모량과 함정에서 사용하고 있는 연료의 황성분 함량을 분석하여 항해 시 선박에 적용되고 있는 오염물질 기여도 조사(emission inventory) 방법론을 해군함정에 적용시켜 정속항해 조건에서 배기가스 총 배출량을 예측하는 것이다.

• 한국대기환경학회지
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• 제27권4호
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• pp.405-415
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• 2011

The objective of this study was to compare greenhouse gas emissions from road transportation by calculation methods (Tier 1, Teir 2, and Tier 3). Tier 1 based on 2006 IPCC guidelines default emission factor and amount of fuel consumption. The Tier 2 approach is the same as Tier 1 except that country-specific carbon contents of the fuel sold in road transport are used. Tier 2 based on emission factor of guidelines for local government greenhouse gas inventories (Korea Environment Corporation), the fuel consumption per one vehicle, and the registered motor vehicles. The Tier 3 approach requires detailed, country-specific data to generate activity-based emission factors for vehicle subcategories (National Institute of Environmental Research) and may involve national models. Tier 3 calculates emissions by multiplying emission factors by vehicle activity levels (e.g., VKT) for each vehicle subcategory and possible road type. VKT was estimated by using GIS road map and traffic volume of the section. The GHG average emission rate by the Tier 1 was 728,857 $tonCO_2eq$/yr, while Tier 2 and Tier 3 were 864,757 $tonCO_2eq$/yr and 661,710 $tonCO_2eq$/yr, respectively. Tier 3 was underestimated by 10.1 and 20.7 percent for the GHG emission observed by Tier 1 and Tier 2, respectively. Based on this study, we conclude that Tier 2 is reasonable GHG emissions than Tier 1 or Tier 3. But, further study is still needed to accurate GHG emission from Tier 3 method by expanding the traffic survey area and developing the model of local road traffic.

• 한국환경농학회지
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• 제40권4호
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• pp.295-312
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• 2021

BACKGROUND: Global warming is one of the most pressing environmental issues which concomitantly complicates global climate change. Methane emission is a balance between methanogenesis and methane consumption, both of which are driven by microbial actions in different ecosystems producing methane, one of the major greenhouse gases. Paddy fields are major sources of anthropogenic methane emissions and could be compounded by organic fertilization. METHODS AND RESULTS: Literature reviews were conducted to give an overview of the global warming conditions and to present the relationship of carbon and methane to greenhouse gas emissions, and the need to understand the underlying processes of methane emission. A more extensive review was done from studies on methane emission in paddy fields under organic fertilization with greater emphasis on long term amendments. Changes in paddy soils due to organic fertilization include alterations of the physicochemical properties and changes in biological components. There are diverse phylogenetic groups of methanogens and methane oxidizing bacteria involved in methane emission. Also, multiple factors influence methanogenesis and methane oxidation in rice paddy fields under organic fertilization and they should be greatly considered when developing mitigating steps in methane emission in paddy fields especially under long term organic fertilization. CONCLUSION(S): This review showed that organic fertilization, particularly for long term management practices, influenced both physicochemical and biological components of the paddy fields which could ultimately affect methanogenesis, methane oxidation, and methane emission. Understanding interrelated factors affecting methane emission helps create ways to mitigate their impact on global warming and climate change.