• Title/Summary/Keyword: 가변적 배출계수

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Variable Emission Factor Prediction Model for An Air Quality Assessment of Transportation Projects (교통사업의 대기질 평가를 위한 가변적 배출계수 예측모형)

  • Lee, Gyu-Jin;Choe, Gi-Ju;Yu, Jeong-Hun;O, Se-Chang
    • Journal of Korean Society of Transportation
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    • v.29 no.6
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    • pp.117-128
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    • 2011
  • In this study, a model is developed to predict emission factors, which aims to objectively evaluate the impact of transport projects on air quality. Two emission prediction models for the years of 2015 and 2030 are developed using the historical trends in vehicle aging and vehicle deterioration factors. The analysis results show that the emission factors under the operating speed of 30km/h for the year 2030 are 5~37% and 2~83% less than those used in the current studies for passenger cars and bus/trucks, respectively. The statistically validated experiment results demonstrate the applicability of the proposed model to evaluation of the impact of transport policies on air quality.

Hydrulic Characteristics Analysis of under flow in Vertical Lift Weir (하단배출형 연직가동보의 수리특성 분석)

  • Choi, Yong Hwan;Lee, Ji Haeng;Choi, Heung Sik
    • Proceedings of the Korea Water Resources Association Conference
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    • 2016.05a
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    • pp.464-464
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    • 2016
  • 기존의 고정보 설치에 따른 문제점으로 보 상류의 유속감소로 인한 유사나 오니의 퇴적으로 저류량의 감소, 홍수위 상승, 수질악화, 보 상 하류간 연속성의 단절 등의 개선을 위한 연직가동보에서의 수리특성을 분석하였다. 그에 따라 본 연구에서는 gate의 개도 높이를 조절함으로써 하상 퇴적물을 배출하고 수위와 유량을 조절할 수 있는 하단배출형 가동보를 길이 10 m, 폭 0.4 m, 높이 0.4 m의 가변경사식 수로에 다단식으로 배치하여 유량과 가동보 개도 높이에 따른 수리 특성을 분석하였다. 연직가동보의 개도에 따른 방류량의 수리특성으로 유량계수를 분석하고 그에 따른 보 상류에서 저류특성을 분석하였다. 유량과 연직가동보의 개도에 따른 수리특성으로 도수현상에 따른 수축계수, 도수길이, 도수높이를 분석하고 그에 따른 관계식을 제시하였다. 연직가동보 주변의 수리특성의 분석을 위한 차원해석을 실시하고 지배적인 무차원 변수를 도출하였다.

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Efficiency Evaluation of Mobile Emission Reduction Countermeasures Using Data Envelopment Analysis Approach (자료포락분석(DEA) 기법을 활용한 도로이동오염원 저감대책의 효율성 분석)

  • Park, Kwan Hwee;Lee, Kyu Jin;Choi, Keechoo
    • Journal of Korean Society of Transportation
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    • v.32 no.2
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    • pp.93-105
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    • 2014
  • This study evaluated the relative efficiency of mobile emission reduction countermeasures through a Data Envelopment Analysis (DEA) approach and determined the priority of countermeasures based on the efficiency. Ten countermeasures currently applied for reducing greenhouse gases and air pollution materials were selected to make a scenario for evaluation. The reduction volumes of four air pollution materials(CO, HC, NOX, PM) and three greenhouse gases($CO_2$, $CH_4$, $N_2O$) for the year 2027, which is the last target year, were calculated by utilizing both a travel demand forecasting model and variable composite emission factors with respect to future travel patterns. To estimate the relative effectiveness of reduction countermeasures, this study performed a super-efficiency analysis among the Data Envelopment Analysis models. It was found that expanding the participation in self car-free day program was the most superior reduction measurement with 1.879 efficiency points, followed by expansion of exclusive bus lanes and promotion of CNG hybrid bus diffusion. The results of this study do not represent the absolute data for prioritizing reduction countermeasures for mobile greenhouse gases and air pollution materials. However, in terms of presenting the direction for establishing reduction countermeasures, this study may contribute to policy selection for mobile emission reduction measures and the establishment of systematic mid- and long-term reduction measures.