• 한국분무공학회지
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• 제23권3호
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• pp.128-135
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• 2018

In this study, the following conclusions could be obtained from the analysis of emissions contribution rates and features for contaminated emissions by 13,456 gasoline vehicles passed in the vehicle load test (ASM-idle) under the inspection year 2013 to 2017. It was confirmed that the contamination of the CO, HC, NOx by the displacement is reduced on over 3L engine. As a result of comparing the exhaust gas in the low speed idle mode and the AS2525 mode, the exhaust gas in the low speed idle mode was measured high. It is estimated that if ISG function is applied, emissions from idle condition will be reduced. NOx emissions were reduced when the engine power was above 200HP. It has been confirmed that the amount of exhaust emissions are significantly reduced for vehicles manufactured after 2004. As a result of analyzing the exhaust gas according to the season, it is judged that there is a correlation between HC and NOx according to the ambient temperature. The concentration of exhaust emission in vehicles with high accumulated distance increases, which is considered to be the result of aging of the vehicle.

• 한국연소학회:학술대회논문집
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• 한국연소학회 2001년도 제23회 KOSCO SYMPOSIUM 논문집
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• pp.51-56
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• 2001

An experiment using preheated air in the coaxial diffusion flame burner was carried out in order to decrease NOx emission and improve the thermal efficiency. Preheated air combustion generally produces high NOx emissions but it was known very well to reduce NOx emission by diluting the combustion air with inert gas in preheated air combustion. In our study, $N_2$ gas was used for diluent and propane was utilized for fuel. We set the combustion air temperature on 300K, 500K, 700K, 900K and dilution level from 21% to 10% in terms of oxygen concentration. NOx emission increased along increment of combustion air temperature and decreased along increment of dilution level(lowering of oxygen concentration in combustion air). Flame-off limit with dilution level enhanced, flame length became longer and the location of maximum flame temperature became lower with increasing of combustion air temperature.

• 경영과학
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• 제29권2호
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• pp.157-165
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• 2012

This paper researches on the effective and efficient logistics policy for the parcel express company. The paper derives new policy by considering the number of used vehicles, carbon emission amount, delivery completion time, etc. The maximum waiting of delivery is considered as the time limit T day. To verify the effectiveness of the derived policy, the data of 30 days is generated, and it was shown that the derived policy is very effective compared with the conventional one.

• 한국항해학회지
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• 제23권2호
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• pp.61-66
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• 1999

It is being more and more difficult to suppress emissions from electronic products using PCB(Printed Circuit Board) to the limit. Therefore, the exact evaluation of the emission from PCB has been more important to reduce the required time and the cost at the design phase of the products, especially on board ship's equipments. This research has evaluated the emission radiated from PCB based on the theoretical approach of SDA(Spectral Domain Analysis), which is available to analyze microwave stripline, coplanar line, patch antenna, etc. According to the theoretical results, it has been clearly shown that the emission radiated from PCB is reduced as the thickness of PCB is thinner, the permittivity of PCB is higher, the length of stripline is shorter, and the frequency is lower.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2008년도 춘계학술대회논문집
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• pp.529-533
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• 2008

Recently in Korea, noise is one of the most important social issues because the living standard becomes more higher. Railway noise is also annoying one in our society, although railway has very positive role in our country. The major measures for mitigation of railway noise in Korea are rail welding and installation of noise barrier on the noisy area. But these measures have its own limit for the calm and comfortable living environment. In Europe the railway noise problem has been treated more systematically and aggressively, there has been emission noise standard for Trans-European rail network. In this paper, the trend of noise standard for railway vehicles will be reported and the check point for our country will be discussed.

• 분석과학
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• 제5권3호
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• pp.263-268
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• 1992

원통형 microwave cavity를 이용한 플라즈마 발생장치를 기체크로마토그라프에 연결하여 원자발광 검출기로 사용하였다. 이 장치를 이용하여 몇 가지 원소에 대한 검출한계를 결정하였다. 브롬과 황에 대한 검출한계는 각각 0.46 pg/s 와 0.51 ng/s였으며, 운반기체의 유량이 10~20 mL/min에서 안정한 플라즈마를 얻을 수 있었다.

• Tribology and Lubricants
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• 제15권4호
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• pp.328-334
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• 1999

Acoustic emission (AE) sensor was used to evaluate the wear-life of CrN-coated steel disks with 1 $\mu\textrm{m}$ and 4 $\mu\textrm{m}$ coating thickness. The relationship between Af and friction signal from scratch test and sliding test was investigated. The first spatting of CrN film was detected by AR signals in the early stage of coating failures, and overall failures by friction signals. Therefore, the conservative design for coating-life should be done using the results of AE signals. Using the percent contact load, the ratio of sliding normal load to the critical scratch load and the number of cycles to failure was measured to predict the wear-life of CrN film. On the wear-life dia-gram the percent contact loads and the number of cycles to failure showed a good linear relationship on the log coordinate. As the load percentage was decreased, the diagram showed that the wear-limits, at which the coated steels survived more than 35,000 cycles, were about 4∼5% of the critical scratch loads.

• 오토저널
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• 제8권1호
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• pp.29-39
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• 1986

The purpose of this study is to develop an exhaust gas recirculation valve for reduction of the NOx emission of the gasoline engine. In this study the back pressure modulated(BPM) EGR system was developed and tested for the 1.6$\ell$ gasoline engine. By this system 50% of NOx emission was reduced at 7% EGR rate. Fuel consumption and CO emission were not affected by EGR but HC was increased up to the level of allowable limit. Overall operation was satisfactory. As a result of this study, the technics for developing EGR valve and adjusting the engine for EGR have been established.

• 한국대기환경학회지
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• 제28권4호
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• pp.396-410
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• 2012

The purpose of this study is to quantify the contribution of high emitting vehicles to mobile emission inventories. Analyzed emission data include $NO_x$, HC, and CO results, which were measured through the vehicle Inspection and Maintenance (I/M) program in Seoul metropolitan area. The high emitting vehicles were identified as the top 5% worst polluting cars of the fleet. We estimated that 5% of the gasoline passenger car fleet, which is high emitters, generated 25.5% of $NO_x$, 34.5% of HC, and 66.1% of CO emissions of total inventories for gasoline passenger car fleet in year 2010. In the study, we identified that the older vehicles (older than ten years) and high mileage vehicles (more than 120,000 km driven) comprised high emitter fleet with 70.9% and 71.2%, respectively. The emission contribution of high emitters became larger in younger fleet than in the older fleet. This is due to the reduced emission rates in newly manufactured vehicles, which were developed under the more stringent emission regulation limits. This analysis implies that high emitters could be responsible for an even larger fraction of total vehicular emissions as more advanced technology vehicles are being incorporated into the current vehicle fleet. The findings suggested that the high emitting vehicles should be primarily considered for in-use vehicle emission management program, such as I/M, accelerated vehicle retirement, or catalytic converter replacement, in order to enhance the effectiveness of selected program.

• 한국농림기상학회지
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• 제24권4호
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• pp.285-294
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• 2022

본 연구에서는 벼 재배 부문 질소 비료 시용에 따른 N₂O 배출량 평가를 위해 경기도 화성시 경기도농업기술원 내 벼논에서 폐쇄형 챔버법으로 측정하였으며, 미량의 N₂O 배출량이 과소평가되지 않도록 현장 측정 플럭스 자료에 대한 방법검출한계(MDL; Method Detection Limit)와 실용정량한계(PQL; Practical Quantitation Limit)를 산정하고 이를 바탕으로 QA/QC 방법을 설정하여 원시자료와 QA/QC 방법을 수행한 N₂O 배출량을 비교하였다. 벼 재배 표준시비량인 3요소 N-P₂O₅-K₂O = 90-45-57 kg ha^-1 기준 질소 0배, 1배, 1.5배, 2배로 4처리하여 평가한 N₂O 배출량 변화에서는 N₂O 배출량이 가장 적었던 질소 0배 처리구 외에는 원시자료와 QA/QC 방법을 수행한 자료 모두 유의한 차이가 없었으며, 질소 비료 시용량이 많을수록 N₂O 배출량이 높게 나타나 질소 1배 처리구 대비 질소 2배 처리구는 191% 높게 나타났다. 질소 시비량에 따른 N₂O 배출량의 회귀관계 분석에서는 지수회귀모형에서 결정계수가 가장 높았으며, 선형회귀모형으로 산정한 기본배출계수는 IPCC에서 제공하는 기본배출계수 값과 동일하게 나타났다. 본 연구결과는 농업부문 온실가스 배출량 산정을 위해 보편적으로 사용하고 있는 폐쇄형 챔버법의 플럭스 자료에 대한 QA/QC 방법을 제시하고, 원시자료와의 비교분석을 통해 질소 비료 시비에 따른 벼논에서 발생하는 N₂O 배출량에 대한 신뢰성 있는 평가가 가능한 것으로 판단할 수 있다.