• The Transactions of The Korean Institute of Electrical Engineers
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• v.60 no.1
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• pp.109-113
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• 2011

This paper analyzes the noise sources of an LED lighting module with TRIAC dimming control and proposes an improved EMI filter design for the reduction of conducted noise emission. TRIAC dimming invokes problems of input oscillation and capacitor overvoltage at the lighting module. The proposed double LC filter reduces high noise level from the circuit. The experimental and simulation results show that this approach can make significant contributions to the reduction of conducted noise emission from an LED lighting module with TRIAC dimming control.

• Journal of Korean Society of Transportation
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• v.36 no.1
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• pp.1-12
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• 2018

The purpose of this study is to establish a methodology for evaluating quantitative effects of transportation GHG (greenhouse gas) reduction-related policies that were implemented based on the reduction goals of transportation GHG and effective implementation plans. This study uses a modal utility function and demand estimation models as well as a GHG emission basic unit estimation model by each transportation mode based on actual traffic and emission data. The results showed that the effects of GHG reduction policies such as electric vary from region to region, and from vehicle to vehicle. It is also confirmed that an eco-drive promotion policy, one of the lowest budget policies, is expected to contribute to high reduction in GHG. In addition, not only automobile emission improvement policies but also the promotion policies of public transportation are expected to highly reduce GHG as confirmed quantitatively in this study. The results of this study are expected to be useful for national and local governments' evaluation of GHG reduction policies to cope with the post 2020.

• Journal of Environmental Impact Assessment
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• v.22 no.3
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• pp.195-201
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• 2013

Local governments are establishing their own greenhouse gas reduction goal and are playing a important role to respond to climatic changes. However, there are difficulties in quantitative analyses such as estimation of future greenhouse gas emission and computation of reduction potential, which are procedures required to establish mid to long term strategies to realize of low carbon society by each local governments. Also, reduction measures must reflect characteristics of each local government, since the reduction power of each local government can differ according to characteristics of each. In order to establish strategies that reflect characteristics of local governments, types of greenhouse gas emission from cities were classified largely into residential city, commercial city, residential commercial city, agriculture and fishery city, convergence city, and industrial city. As a result of analyzing basic unit of greenhouse gas emission by local government during 2007 in terms of per population, household and GRDP based on the type classification, significant results were deduced for each type. To manage the amount of the national greenhouse gas, reduction measures should be focused on the local governments that emits more than the average of each type's GHG emission.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2018.05a
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• pp.35-36
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• 2018

According to the nation's greenhouse gas emission statistics, greenhouse gas emissions have been stiffly increasing. Accordingly, the importance of CO₂ reduction is more getting focused over the world. This trend makes the construction equipment be considered as a major target of reduction due to the large volume of emission. This study suggests the feasible methodology for estimating CO₂ emission from construction equipment and for being easily applied on the job sites. The methodology is based on the collection from the segmented CO₂ emission information of construction equipment. This study allows site personnels to estimate the total amount of CO₂ and to take appropriate actions for reasching the environmental regulations.

• Journal of ILASS-Korea
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• v.22 no.3
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• pp.122-128
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• 2017

Currently, the proportion of diesel vehicles in all automobile has grown significantly over the past few years. Air pollutant also grew up and became a social problem. In particular, the issue of NOx emissions caused by NOx high emission in real driving has become a global issue. Despite the fact that the regulatory and reduction project of the new vehicle is actively carried out, there are no existence regulations of In-use diesel vehicle's NOx emission. Therefore, the emission characteristics of the in-use diesel vehicles were investigated to seek ways to reduce NOx emissions in this study. The test targets were used in 237 close inspection of exhaust gases and model year varied from 1996 to 2011. However, the classification of emissions by emission standards differed considerably from NOx emissions. This means that the selection method for early retirement targets should be converted from model year to amount of emissions. If the current early retirement program was applied to the existing system, pre-Euro 3 was 22.530 g/km and Euro 4 was 21.810 g/km to NOx reduction. However, when the vehicle was changed to high emission target vehicle, NOx reduction increase maximum 84.705 kg/yr. According to the study results, an effective reduction in NOx emissions can be achieved if an earlier target in expanded to Euro 4 vehicles.

• Journal of the Korean Society for Marine Environment & Energy
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• v.7 no.2
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• pp.57-63
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• 2004

In this paper, the NOx emission and the reduction technologies of NOx emission for domestic marine diesel engine were investigated. At first, the present production status of domestic marine diesel engines was investigated. In the next, the NOx emission of domestic marine diesel engines was investigated. Finally, the present status of a reduction technologies of NOx emission was investigated. From this investigation, It could be founded that the domestic marine diesel engines satisfied the IMO current NOx regulations, however the higher technologies must be studied to prepare the more severe IMO regulations of the near future.

• International Journal of Automotive Technology
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• v.6 no.6
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• pp.591-598
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• 2005

A three-way catalyst system of a natural gas vehicle (NGV) has characteristics of higher fuel consumption and higher thermal load than a lean-bum catalyst system. To meet stringent emission standards in the future, NGV with the lean-bum engine may need a catalyst system to reduce the amounts of HC, CO and NOx emission, although natural gas system has low emission characteristics. We conducted experiments to evaluate the conversion efficiency of the NOx reduction catalyst for the lean-burn natural gas engine. The NOx reduction catalysts were prepared with the ${\gamma}-Al_{2}O_3$ washcoat including Ba based on Pt, Pd and Rh precious metal. In the experiments, effective parameters were space velocity, spike duration of the rich condition, and the temperature of flowing model gas. From the results of the experiments, we found that the temperature for maximum NOx reduction was around $450^{\circ}C$, and the space velocity for optimum NOx reduction was around $30,000\;h^{-1}$ And we developed an evaluation model of the NOx reduction catalyst to evaluate the conversion performance of each other catalysts.

• 한국연소학회:학술대회논문집
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• 2015.12a
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• pp.295-296
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• 2015

We presented the methods calculating the reduction efficiency of nitrogen oxide for the low $NO_x$ burner as the pollution prevention facilities. The standard $NO_x$ concentration was used on the emission factor of LNG, $3.7g/m^3$. The $NO_x$ reduction efficiency based on the $NO_x$ concentration was presented and the relationships between the $NO_x$ concentration and the emission factor or the specific heat emission factor were derived. These results could be accurately reflected on calculating the amount of the nitrogen oxide emissions. In addition, according to the arrangement of the low $NO_x$ burners the methods of applying their $NO_x$ reduction efficiency were proposed. The $NO_x$ reduction efficiency for the facilities consisting of the low $NO_x$ burners and the non-low $NO_x$ burners could be estimated with information about the reduction efficiency of each low $NO_x$ burners, the fuel consumption rate, and the heating value of fuel.

• 한국연소학회:학술대회논문집
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• 2001.11a
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• pp.153-160
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• 2001

The combustion test used DTF was performed to obtain the characteristics of NOx emission and reduction. In this test, major factor of NOx emission was a stoichiometric air ratio. At the onset of combustion to be rich oxygen, NOx was produced rapidly. Optimum condition for NOx reduction was formed under about AR:0.7 in the combustion test of Alaska coal. Investigations were undertaken with 200KW(th) test combustor. In combustion test, the major variables were coal feed ratio of center/outer, stoichiometric air ratio at the onset of combustion. The lowest NOx emission, 182ppm(6% O2 base), was achieved at about AR:0.6 of the first combustion stage with low NOx burner. Also, unburned carbon content of char collected in this combustion condition was about 1wt%.

• Journal of Environmental Science International
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• v.20 no.2
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• pp.207-214
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• 2011

Non-Annex I parties announced the voluntary emission reduction targets including the U.S. in the conference of party. NAMAs would be focused to solve the negotiation clue for the post-kyoto regime. Since the country would not be involved in Annex I parties, the voluntary carbon market would be created for the greenhouse gas reduction targets. According to Bali Roadmap, voluntary carbon market should be constructed by the MRV manners since this country does not belong to Annex I parties. Carbon point system would be proposed by the ways of the international voluntary emission reduction credit. The voluntary carbon market should involve the potential GHG reduction credit and link with the ETS in the country. This study proposed the way of linkage between ETS and voluntary carbon market including the carbon-point system.