• Korean Journal of Soil Science and Fertilizer
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• v.46 no.6
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• pp.463-468
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• 2013

The level of nitrous oxide ($N_2O$), a long-lived greenhouse gas, in atmosphere has increased mainly due to anthropogenic source, especially application of nitrogen fertilizers. Quantifying $N_2O$ emission from agricultural field is essential to develop national inventories of greenhouse gases (GHGs) emission. The objective of the study was to develop emission factor to estimate direct $N_2O$ emission from agricultural field in Gangwon-do, Korea by measuring $N_2O$ emissions from potato (Solanum tuberosum), red pepper (Capsicum annum L.), and Chinese cabbage (Brassica campestris L.) cultivation lands from 2009 to 2012. Accumulated $N_2O$ emission was $1.48{\pm}0.25kg$ $N_2O-N\;ha^{-1}$ for red pepper, $1.27{\pm}0.27kg$ $N_2O-N\;ha^{-1}$ for potato, $1.49{\pm}0.06kg$ $N_2O-N\;ha^{-1}$ for Chinese cabbage cultivated in spring, and $1.14{\pm}0.22kg$ $N_2O-N\;ha^{-1}$ for fall Chinese cabbage. Emission factor of $N_2O$ calculated from accumulated $N_2O$ emission, nitrogen fertilization rate, and background $N_2O$ emission was $0.0051{\pm}0.0016kg$ $N_2O-N\;ha^{-1}$ N for cropland in Gangwon province. More extensive study is deserved to be conducted to develop $N_2O$ emission factor for upland crops in Korea through examining the emission factors from various regions and crops because $N_2O$ emission is influenced by many factors including climate characteristics, soil properties, and agricultural practices.

• Environmental and Resource Economics Review
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• v.32 no.2
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• pp.127-147
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• 2023

This study is trying to analyze the economic effect of replacing thermal power generation, one of the government's carbon-neutral policies, with new and renewable energy. For this analysis, scenario A is set to replace 100% of thermal power generation with new and renewable energy, and scenario B is set to replace 60% of thermal power generation with new and renewable energy. In addition, costs are incurred when replacing thermal power generation with new and renewable energy, and scenario 1 is the same cost as the current cost, and scenario 2 is120% higher than the current cost. Therefore, when converting thermal power generation to new and renewable energy, the scenarios are largely organized into four cases. In the case of replacing thermal power generation with new and renewable energy, the production inducement coefficient of thermal power generation decreased from the current level regardless of the scenario. However, the value-added inducement coefficient and the greenhouse gas emission inducement coefficient are lower than the current level when thermal power is converted to renewable energy by 100%, while the value-added inducement coefficient and greenhouse gas emission inducement coefficient are higher than the current level. In addition, the greenhouse gas emission induction coefficient of most industries was found to decrease, while the production induction coefficient and the value-added induction coefficient increased. Scenario A seems appropriate because the purpose of the government's policy is to reduce greenhouse gas emissions by converting thermal power into new and renewable energy. However, as a result of this, the production inducement coefficient and value-added inducement coefficient of some industries decrease, so the government's support policy is needed to solve this problem

• The Bulletin of The Korean Astronomical Society
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• v.35 no.1
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• pp.69.1-69.1
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• 2010

IC 443 is famous for its interaction with nearby molecular clouds and intense H2 emission lines in infrared. Therefore, it has been studied extensively for the understanding of molecular shocks. We observed H2 mission lines toward the shock-cloud interaction regions of IC 443, known as clumps B, C, and G. The observations were performed with the InfraRed Camera (IRC) onboard a satellite AKARI over 2.5-5.0 um, where previous space observations, e.g. Infrared Space Observatory (ISO) and Spitzer, do not cover. Our AKARI observations provide spectra of sequential pure-rotational and ro-vibrational H2 emission lines. For the clumps C and G, combining with previous mid-infrared observational results, we found that the H2 level populations show a significant separation between v=0 and v=1 levels; v=1 levels are under-populated than v=0 levels, therefore, the population cannot be described by two temperature LTE model, as many people have analyzed for the shocked H2 gas. We also applied the thermal admixture model, dN(H2; T)~T^(-b) dT, with varying ortho-to-para ratios according to the temperature, to describe the level population, and obtained plausible ranges of the H2 gas density and power-law index b.

• Journal of Korean Society of Transportation
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• v.29 no.5
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• pp.55-65
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• 2011

In effort to estimate sustainability of the transportation sector, this study conducts a comparative analysis of methodology suggested for measuring greenhouse gas emission. There are two approaches proposed by the UN IPCC: 1) top-down approach (TDA) based on the amount oil sales, and 2) bottom-up approach (BUA) utilizing the velocity of moving source and traffic volume data. The subject areas for analysis were selected based on research results by the Korea Transportation Institute that evaluate traffic sustainability of each local government. Gwacheon-si being one of the top ranked areas in sustainability, and Anseong-si being ranked at the 7th level were analyzed. By the tier 1 methodology, Gwacheon-si and Anseong-si are estimated to create 74,813ton/yr, and 584,125ton/yr of the greenhouse gas emission, respectively. The tier 3 methodology, however, estimates Gwacheon-si and Anseong-si to create 91,462ton/yr, and 163,801ton/yr of the emission, respectively. Comparison of the two estimated emissions shows considerable differences; i.e., the tier 3 method over estimates Gwacheon-si's emission by 22.3% whereas it underestimates Anseong-si's greenhouse gas emission by the factor of about 3.5 compared to the emissions obtained from the tier 1 method. The result from this study implies that the traffic-sustainability-index based grade of each local government can be evaluated differently by the method adopted for measuring greenhouse gas emission.

• Journal of Korean Society for Atmospheric Environment
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• v.1 no.1
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• pp.83-92
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• 1985

In odrder to survey the emission level of air pollutants from diesel vehicles, was measured CO, HC, NOx and smoke of 4 types of domestic-use diesel engines under various conditions. The emission of CO, HC and NOx tested by 6-Mode test method and smoke emission by full load test met the permissible vehicle emission standard. Pollutant emission rates of diesel engines were different according to engine operating conditions, that is, engine load and engine speed. Generally, CO and HC was emitted more at low load and NOx at high load but the trend was quite different by the type of engines. In exhaust gas, $NO_2$ portion of NOx emission was high, specially at low speed and low load. The correlation equation between CLD(NOx) and NDIR(NO) method of nitrogen of nitrogen oxides analysis was y = 1.10x - 3.48 (y: CLD method) as a result of 6-mode test.

• International Journal of Automotive Technology
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• v.7 no.4
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• pp.407-413
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• 2006

The liquefied petroleum gas(LPG), mixture of propane and butane, has the potential to reduce toxic hydrocarbon emissions and inhibit ozone formation due to its chemical composition. Conventional mixer systems, however, have problems in meeting the future lower emission standards because of the difficulty in controlling air-fuel ratio precisely according to mileage tar accumulation. Liquid Phase LPG injection(LPLi) system has several advantages in more precise fuel metering and higher engine performance than those of the conventional mixer type. On the other hands, leakage problem of LPLi system at the injector tip is a main obstacle for meeting more stringent future emission regulations because these phenomena might cause excessive amount of THC emission during cold and hot restart phase. The main focus of this paper is the development of a leaked fuel recirculation system, which can eliminate the leaked fuel at the intake system with the activated carbon canister. Leaked fuel level was evaluated by using a fast response THC analyzer and gas chromatography. The result shows that THC concentration during cold and hot restart stage decreases by over 60%, and recirculation system is an effective method to meet the SULEV standard of the LPLi engine.

• Spatial Information Research
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• v.19 no.6
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• pp.11-18
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• 2011

Urban space is the main contributor of greenhouse gas emissions, a primary cause of global warming. In order to reduce greenhouse gas emissions, planning at a city-level is necessary. The aim of this research is to develop a carbon emission model which can be used to create and manage urban spaces. In order to achieve this aim, the following methodologies were utilized. First, urban planning criteria related to population, landuse, and activity level were selected through theoretical speculation. Second, carbon dioxide emission was calculated based on electricity, gas energy, heating, petroleum, and water usages. Third, Seoul was selected as a case study city, and a carbon emission model was developed through a relational analysis between Seoul's urban planning criteria and carbon emissions. Thus far, various efforts have been made to respond to climate changes in urban spaces, but these have been limited to analyzing contributing factors in terms of their total amounts of carbon emissions in the entire city. However, the carbon emission model of this study is derived from urban planing criteria at a detailed scale. This sets our study apart from other studies by demonstrating a specific model in a local setting which can be utilized for lowering carbon emissions at a city level.

• Journal of ILASS-Korea
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• v.23 no.4
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• pp.212-220
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• 2018

As increase the number of vehicles, the issue of greenhouse gas that was emitted by them became important. As a result, greenhouse gas (GHG) regulations are being strengthened and efforts are being actively made to reduce greenhouse gas emissions in the automotive industry. In the other hand, regulations for harmful emission of vehicles have been reinforced by step. Especially, the lastly applied step, so called Euro 6, not only decreased NOx limit down to half of Euro 5 but also introduced real driving emission limit for NOx and PN. It is a challenge for manufacturers to meet the recent GHG regulation as well as the latest emission regulation. To overcome these regulations a De-NOx after-treatment system is being applied to diesel vehicles that are known emitting the lowest GHG among conventional internal combustion engines. At the time of the introduction of Euro 6 emission standard in Korea, in the domestic fuel economy certification test, some diesel vehicles emitted more $CH_4$ than Euro 5 vehicles. As a result, it was confirmed that LNT-equipped vehicles emitted a high level $CH_4$ and the level exceeded the US emission standard. In order to determine the reason, various prior literature was investigated. However, it was difficult to find a detailed study on the methane increase with LNT. In this paper, to determine whether the characteristics of vehicles equipped with LNT the affects the above issue and other greenhouse gases, 6 passenger cars were tested on several emission test modes and ambient temperatures with a environment chamber chassis dynamometer. 2 cars of these were equipped with LNT only, other 2 cars had SCR only, and LNT + SCR were applied to remaining 2 cars. The test result shown that the vehicles equipped with LNT emitted more $CH_4$ than the vehicles with SCR only. Also, $CH_4$ tended to increase as the higher acceleration of the test mode. However, as the test temperature decreases, $CH_4$ tended to decreased. $CO_2$ was not affected by kinds of De-NOx device but characteristic of the test modes.

• Journal of the Korean Society of Combustion
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• v.10 no.1
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• pp.1-6
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• 2005

This paper presents the combustion characteristics of hydrocarbon fuel from a conventional pressure-swirl nozzle of a small-scale burner. The nozzle has orifice diameters of 0.256 mm and liquid flow rates ranging from 50 to 64 mL/min were selected for the experiments. The furnace temperature distribution along the axial distance, the gas emission such as CO, $CO_2$, NOx, $SO_2$, flue gas temperature, and combustion efficiency were studied. The local furnace and flue gas temperatures decreased with an increase in air velocity. At injection pressures of 1.1 and 1.3 MPa the maximum furnace temperatures occurred closer to the burner exit, at an axial distance of 242 mm from the diffuser tip. The CO and $CO_2$concentrations decreased with an increase in air velocity, but they increased with an increase in injection pressure. The effect of air velocity on NOx was not clearly seen at low injection pressures, but at injection pressure of 1.3 MPa it decreased with an increase in air velocity. The effect of air velocity on $SO_2$ concentration level is not well understood. The combustion efficiency decreased with an increase in air velocity but it increased with an increase in injection pressure. It is recommended that injection pressure less than 0.9 MPa with air velocity not above 8.0 m/s would be suitable for this burner.

• Proceedings of the Korean Society for Agricultural Machinery Conference
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• v.10 no.1
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• pp.76-82
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• 2005

This paper presents the combustion characteristics of hydrocarbon fuel from a conventional pressureswirl nozzle of a small-scale burner. The nozzle has orifice diameters of 0.256 mm and liquid flow rates raging from 50 to 64 mL/min were selected for the experiments. The furnace temperature distribution along the axial distance, the gas emission such as CO, $CO_2,\;NOx,\;S0_2,$ flue gas temperature, and combustion efficiency were studied. The local furnace and flue gas temperatures decreased with an increase in air velocity. At injection pressures of 1.1 and 1.3 MPa the maximum furnace temperatures occurred closer to the burner exit, at an axial distance of 242 mm from the diffuser tip. The CO and $CO_2$ concentrations decreased with an increase in air velocity, but they increased with an increase in injection pressure. The effect of air velocity on NOx was not clearly seen at low injection pressures, but at injection pressure of 1.3 MPa it decreased with an increase in air velocity. The effect of air velocity $SO_2$ concentration level is not well understood. The combustion efficiency decreased with an increase in air velocity but it increased with an increase in injection pressure. It is recommended that injection pressure less than 0.9 MPa with air velocity not above 8.0 m/s would be suitable for this burner.