• 발명특허
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• 제24권4호통권277호
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• pp.22-25
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• 1999

• 화약ㆍ발파
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• 제12권4호
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• pp.66-69
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• 1994

• 한국대기환경학회지
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• 제30권4호
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• pp.327-338
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• 2014

The objective of this study is to enhance the effectiveness of Korean Inspection and Maintenance (I/M) program. Three main tasks are: to measure pollutant emissions of in-use light-duty diesel vehicles (LDVs); to evaluate the validity of existing smoke control scheme for low-smoke-emitting vehicles, which have diesel particulate filters, DPF, to meet stringent Euro-5 emission limits; and to assess the necessity and the benefit of $NO_x$ inspection, which is not involved in current I/M program. We measured second-by-second smoke, particulate and gaseous emissions of 27 LDVs using opacity smoke meter, photo-acoustic soot sensor, and portable emissions measurement system, respectively, under the Korean I/M test driving cycle, KD-147. We find that the DPF plays a key role in controlling soot, which can be considered as black carbon contained in particulate matter. Thus, from an I/M perspective, we believe smoke inspection strategies for Euro-5 diesel vehicles should be more focused on the capability of detecting DPF malfunctions or failures, in order to keep DPF properly functional. Fleet averaged distance-specific $NO_x$ emissions are consistently higher than corresponding emission limits, and the values are similar among pre-Euro-3, Euro-3, and Euro-4 vehicle fleets. These findings indicate that the $NO_x$ inspection should be incorporated into current I/M program in order to manage urban $NO_x$ emissions. This research allows the Korean I/M program keep pace with developments in vehicle technologies, as well as the increased emphasis on $NO_x$ with respect to air quality and human health.

• 융복합기술연구소 논문집
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• 제7권1호
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• pp.15-18
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• 2017

As emission gas regulation of deisel vehicles is strengthened to Euro-6, It becomes difficult to deal with NOx regulated value mainly by EGR without additional after-treatment system. In addition, RDE(Real Driving Emissions) test will be introduced after september 2017. Therefore, It is essential to develop the after-treatment of diesel vehicles which reduce NOx emissions. It is possible to use DOC, DPF, LNT or DOC, DPF and SCR as a after-treatment system for reducing NOx. However, It is expected that the SCR will be applied widely because LNT alone does not have sufficient NOx purification efficiency. In this study, It tried to analyze the efficiency of reducing NOx emissions during the mode test by attaching a NOx sensor to test vehicle. As a result, It was confirmed that NOx emissions was significantly reduce through the after-treatment system from engine. And the NOx reduction efficiency of SCR was about 4.5 times better than DOC, DPF.

• 한국분무공학회지
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• 제23권4호
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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.

• 한국산학기술학회논문지
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• 제19권3호
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• pp.96-103
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• 2018

교량의 온도 설계하중의 기준이 되는 유효온도는 통계적 방법에 의한 분석이 일반적으로 사용된다. 본 연구에서는 통계적 방법을 개선할 수 있는 인공신경망을 구축하여 유효온도를 산정하였다. 강상자형교 시험체를 폭 2.0m, 높이 2.0m, 길이 3.0m, 상부슬래브 0.2m로 제작하였다. 21개의 온도 게이지를 부착하여 3년간(2014~2015) 온도를 측정하였다. 2014~2015년 측정된 온도데이터를 바탕으로 인공신경망을 학습시키고, 그 결과를 Euro code와 비교하였다. Euro code와 통계분석값과의 오차율은 전체 측점에 대하여 4.1%로 분석되었다. 2016년 측정된 온도데이터를 이용하여 인공신경망을 검증하고, 교량 유효온도를 산정하였다. 이 결과는 통계분석 값과 약 3.97%의 차이를 보였다. 이 정도의 오차율은 인공신경망에 의한 분석이 공학적인 측면에서 수용할 수 있는 크기인 것으로 판단된다. 인공신경망은 교량의 온도하중 설계 시 그 지역의 최고 대기온도, 교량 형식, 상부 아스팔트 두께 등 입력 값만 알면 교량의 유효온도를 간편히 예측해 줄 수 있다.

• 한국자동차공학회논문집
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• 제15권5호
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• pp.112-117
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• 2007

With the Euro-4 regulation coming into effect, the domestic car industry is forced to look for newer options to reduce NOX in the exhaust. EGR(Exhaust Gas Recirculation) Cooler is an effective method for the reduction of NOX form a diesel engine. High efficiency, low pressure loss and compactness are desirable features of an EGR Cooler. The cooling performance of EGR depends on the shape of tubes and the location of the entrance and exit. This paper reports the computational work conducted to estimate the performance of EGR cooler with three different cross section tubes and a triangular spiral tube. Three dimensional computation results show that the triangular tube is more effective than circular and rectangular tube. The most effective geometry is a triangular spiral tube with offset inlet and outlet locations.

• 자동차안전학회지
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• 제14권4호
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• pp.84-90
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• 2022

With the popularization of autonomous driving technology, safety has emerged as a more important criterion. However, there are no assessment protocol or methods for AES (Autonomous Emergency Steering). So, this study proposes AES assessment protocol and scenario corresponding to collision avoidance Car-to-Car scenario of Euro NCAP in order to prepare for obstacles that appear after the emergency steering of LV (Leading Vehicle) avoiding obstacles in front of. Autoware-based autonomous driving stack is developed to test and simulate scenario in CARLA. Using developed stack, it is confirmed that obstacle avoidance is successfully performed in CARLA, and the AES performance of VUT (Vehicle Under Test) is evaluated by applying the proposed assessment protocol and scenario.

• 한국산학기술학회논문지
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• 제21권11호
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• pp.740-745
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• 2020

콘크리트 박스거더교의 합리적인 설계 온도하중을 산정하기 위하여, 1개의 교량시험체를 제작하였다. 교량시험체에 설치된 23개의 온도 게이지에서 1년간의 여름과 겨울기간에 30분 간격으로 하루에 48세트의 온도를 측정하였다. 상부 콘크리트와 측벽, 하부슬래브에 두께에 따른 온도변화를 검토하기 위하여 두께에 따라 여러 온도게이지를 부착하였다. 각 측점에서 측정된 온도를 통계 처리하여 추세선과 표준오차를 산정하고, 대표측점의 온도분포와 추세선을 제시하였다. 이를 바탕으로 Euro code에서 제시한 대기온도에서 여름철의 최고 유효온도와 겨울철의 최저 유효온도를 각각 산정하였다. 최고 유효온도는 35℃ 이상에서 Euro code와 비교하여 1.5~2℃ 높게 산정되었고, 최저 유효온도는 -13℃~-19℃에서 0.5~1.1℃로 더 낮게 분석되었다. 양산지방의 50년빈도 최고 및 최저 기온에 따른 본 연구의 유효온도와 비교해 보면, 최고 유효온도는 4.7℃ 높게, 최저 유효온도는 4.5℃ 더 낮게 산정되었다. 점점 높아지는 기후변동을 고려하고, 본 분석의 결과를 반영하면, 현 온도설계기준은 그 범위를 더 크게 하는 것이 필요한 것으로 판단된다.

• 한국분무공학회지
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• 제22권3호
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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.