• Transactions of the Korean Society of Automotive Engineers
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• v.16 no.6
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• pp.104-108
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• 2008

Recently, studies conducted by our research group, revealed the possibility for reducing BSFC, NOx and PM emissions to meet the Euro 4 & 5 legislations. The main objective of the present study is to get better fuel economy in commercial vehicles by considering real driving conditions. Firstly, in order to improve fuel economy on fields, specifically it is required to analyze the driving pattern and make the representative modes from real field data. Secondly, it is performed to make the engine dynometer test to optimize the fuel consumption by reflecting on the representative driving modes, based on the Korea 2008 emission legislation equal to the Euro 4. The engine components such as engine calibration, combustion chamber, turbocharger and ancilliaries were modified to optimize vehicle fuel economy over a typical customer drive cycle whilst still meeting the exhaust emission restrictions. Finally, these results were confirmed by field testing of vehicle equipped with the updated calibration engine. It was placed the two vehicles together traveling the same route and accomplishing the same amount of stops(back to back), in order to evaluate the fuel consumption in comparison to the current vehicle. Through several repeats such as the engine calibration and field test, we could get 3 % to 7.7 % vehicle fuel economy improvements compared to previous vehicle.

• Journal of the Korea institute for structural maintenance and inspection
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• v.18 no.4
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• pp.99-106
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• 2014

In order to study the reasonable design thermal loads, the steel box girder bridge specimen which have no concrete slab was manufactured with the real size dimension. The temperature data were measured for 5 month at the 18 thermo gauges which were attached according to height. The temperature differences between the top and bottom flange in steel box girder specimen were calculated and the temperature gradient models were proposed by the probabilistic method. This proposed model showed a correlation of approximately 97% when compared with the similar model of Euro Code. Thus, the temperature gradient models which were suggested in this study may be used as the basis data in calculating the design load temperature.

• Proceedings of the Korea Concrete Institute Conference
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• 2008.04a
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• pp.601-604
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• 2008

When the concrete is placed, the water, needed for hydration of the cement, is under 30% of W/C including bound and gel water. However, as minimum water content cause bad workability, the W/C have to be higher. Therefore, fresh concrete produce 10${\sim}$20% extra water. As those water remain entrapped air in the concrete, life of the structure is reduced because of the degradation caused by entrapped air. For that reason, if extra water is eliminated, it will be great to improve the durability of the structures. Therefore, this study was performed to verity the fundamental properties through the experiment on the dewatering system using the euro form for eliminating extra water. When the dewatering form was applicated, the compressive strength was increased by 16% than those of normal form. However, the increasing rate of compressive strength got lower as the height is higher. In terms of ultrasonic pulse speed and surface roughness, the dewatering form showed better results than the normal one.

• Journal of Korean Medicine Rehabilitation
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• v.28 no.2
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• pp.91-104
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• 2018

Objectives The aim of this study is to investigate the effect of Acupotomy on the pain reduction and functional improvement of patients with Acute low back pain. Methods We studied 60 patients with Acute low back pain with Numeric Rating Scale (NRS) 5 or higher in admission and had admitted to Department of Korean Medicine Rehabilitation of Daejeon University from March 1, 2017 to October 31, 2017. 30 patients had received Acupotomy combined Korean Medicine treatment(such as acupuncture, moxabustion, herbal medicine, etc) and the other 30 had received Korean Medicine treatment only. The analysis was conducted as a retrospective study which analyzes the patient's medical records. Statistical analysis was performed using the IBM SPSS Statistics 24 program. We used NRS to evaluate pain reduction, used Range of Motion (ROM) and Roland Morris Disability Questionnaire (RMDQ) to evaluate function improvement, and used EuroQol-5 Dimension (EQ-5D) and EuroQoL-Visual Analogue Scale (EQ-VAS) to assess quality of life. Finally, a five-point Likert scale was used to assess treatment satisfaction. Results The analysis revealed that patients who were treated with Acupotomy showed statistically significant NRS reduction, improvement of ROM and RMDQ, improvement of EQ-5D and EQ-VAS and satisfaction compared to those who just recevied Korean Medicine treatment. Conclusions In conclusion, we found that the Acupotomy showed a positive effect on pain resolving, functional rehabilitation and quality of life in patients with Acute low back pain.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.12 no.4
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• pp.1515-1522
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• 2011

This paper proposed the finite element analysis technique for improving the correleration accuracy between FEA and test on a pedestrian lower legform impact. Europe has been evaluating the bumper pedestrian impact by Euro-NCAP, and it will also be applied in a domestic area by K-NCAP in 2013. By using the compression test result of bending resisting stiffener, a pedestrian bumper modeling guide was presented by analayzing the force-displacement curve of stiffener. And by using the sensor measurement results in car pedestrian test, pedestrian impact behavior was analyzed between test and finite element analysis result. Finally, the finite element analysis guide for a pedestrian bumper impact was presented to improve the correleration accuracy.

• Journal of the Korean Institute of Gas
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• v.17 no.5
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• pp.22-27
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• 2013

HCNG engine is performed as a future engine because of high combustion efficiency and eco-friendly property, and is predicted to a brdge of hydrogen vehicles. As EURO-6 regulagion is due to be applied in 2014, consolidated regulations of methane gas that is exhausted from CNG and HCNG vehicles will come into effect. In this studies, methane oxidation catalyst is introduced to remove methane gas from HCNG emissions. Methane oxidation efficiency on catalyst was studied when it is driven long time. And characterization like metal dispersion, surface area was performed to investigate the correlation of catalyst efficiency and characteristics.

• Journal of Power System Engineering
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• v.18 no.6
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• pp.77-83
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• 2014

As the interest on the air pollution is gradually risen up at home and abroad, their vehicle emission regulations have been reinforcing by steps. PM regulation was also reinforced 4times for the last 13years and has been applied to SI vehicles after EURO 5. Additionally, knowing that small particles of PM can easily penetrate deep into lungs PM number was added on the regulation from EURO5+ and is applied to CI vehicles. Also, PN regulation is going to be applied to SI vehicles. But, because the regulation is appled to only a general test mode of each countries that is performed at $25{\pm}5^{\circ}C$, it is unclear whether the regulation can work on the other ambient temperature conditions or not. In this paper, to know that exhaust emission characteristics at the special conditions CI vehicles(CRDi w, w/o DPF) were tested using 5-cycle mode, NEDC mode at 5-ambient temperatures (35, 25, 0, -7 and -15) and the exhaust emission test results were discussed. The results show that the vehicle with DPF emits much low PM(and PM number) on all of the test mode. However, NOx of the other mode was emitted higher than regulation mode. Also. NOx was sharply increased according to decreasing Ambient Temperature.

• Proceedings of the Korea Water Resources Association Conference
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• 2016.05a
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• pp.563-563
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• 2016

국내 강우발생은 기상학적인 영향으로 인하여 장마기간(6~8월)에 집중되어있으며, 최근에는 기후변화의 영향으로 짧은 시간에 많은 양의 강우가 발생하는 집중호우의 발생빈도가 증가하고 있다. 또한, 시간과 지역에 관계없이 국지성호우의 발생빈도 역시 높아지고 있다. 집중호우와 국지성호우는 짧은 시간에 하천수위를 상승시키므로 홍수로 인한 물적 피해가 크게 발생된다. 국토교통부에서는 그동안 홍수예보에 필수적인 우량, 하천수위 등 기초자료를 확보하기 위해 관측소(500여개) 및 홍수량 측정지점(80여개)을 확대하였으며, 관측된 자료는 모두 전산망에 기록, 보관하고 있다. 또한 한강, 금강, 낙동강, 영산강의 경우 홍수통제소에서 홍수량 예측 계산 등을 통해 홍수 예경보를 실시하고 있다. 하지만 4대강을 제외한 중소하천의 홍수예경보에 대한 정보를 찾아볼 수 없으며, 현재 연구가 진행중이다. 강우-유출모형을 활용하여 중소하천의 강우와 유출의 관계를 해석하는 과정은 다양한 인자를 고려해야하지만 중소하천의 경우 하천단면 등 하천자료가 충분히 구축되어 있지 못하므로 유출량 계산에 많은 어려움을 겪고 있다. 이에 본 연구에서는 중소하천의 홍수위 예측을 위해 한강의 과거 수위와 현재 수위만을 활용하여 인공신경망(Artificial Neural Network, ANN)의 학습을 진행하였다. 첫 번째로 ANN을 활용하여 한강유역 중 홍수예보지점(잠수교)의 수위변화에 직접적으로 연관이 있는 5개 수위관측소를 선정하였으며, 과거 장마기간(6~8월)관측 자료를 활용하였다. 두 번째로 홍수예보지점(잠수교)과 5개 수위관측소의 과거 관측수위(2009~2014년)를 인공신경망의 학습자료로 활용하여 모델을 훈련시켰으며, 마지막으로 2015년의 관측수위를 이용하여 ANN의 학습정확도에 대한 검증을 하였다. 본 과정은 수위예측을 위한 ANN의 훈련단계로 Training/Test를 반복하였으며, 학습결과와 2015년 관측수위 비교시 $R^2=0.987$과 상관계수 r=0.994로 유사한 패턴을 보였으나 최대치와 최소치에 대한 오차가 있음을 확인하였다.

• Journal of ILASS-Korea
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• v.23 no.4
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• pp.175-184
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• 2018

Emission characteristics of regulated (NOx, PM, CO, NMHC) and unregulated (VOCs, aldehydes, PAHs) air pollutants were investigated for diesel heavy duty buses equipped with different after-treatment systems (DPF+EGR and SCR) under urban driving cycle. The combustion temperature and the working temperature of SCR catalysts were important to make impact on NOx emissions, whereas PM emissions were low. The alkane groups dominated NMVOCs emissions, making 42.6~59.4% of sum of the NMVOCs emissions. Especially, alkane emissions of DPF+EGR-equipped vehicle included DOC had 14.9~15.5% higher than those of SCR-equipped vehicle due to low efficiency of oxidation catalyst. In the case of individual NMVOCs, n-nonane and propylene emissions highly occupied for DPF+EGR and SCR, respectively. Formaldehyde emissions among aldehydes were the highest and PAHs emissions were hardly detected except naphthalene and phenanthrene. The NMHC speciation has been shown to be the highest of the formaldehyde ranged 20.8~21.5%. The results of this study will be contributed to establish Korean HAPs emission inventory for automobile source.

• The Journal of Korean Obstetrics and Gynecology
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• v.34 no.2
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• pp.157-170
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• 2021

Objectives: The purpose of this study is to report the improvement of vulvodynia and genital pruritus caused by unidentified genital ulcer after Korean medicine treatment. Methods: The patient who complained vulvodynia and genital pruritus caused by unidentified genital ulcers was treated by acupuncture, moxibustion, fumigation, and herbal medicine as Eunhwasagan-tang, Guibi-tang-gami-bang for 5 days. The effect of treatment was evaluated by Numeral Rating Scale (NRS), The 5 level of EuroQol 5 Dimension scale (EQ-5D-5L), EuroQol-Visual Analog Scale (EQ-VAS). Results: After the treatment, the chief complaint and general conditions were improved. NRS was decreased from 8 to 3 and scores of EQ-5D-5L and EQ-VAS were increased from 0.416, 10 to 0.904, 80 each. Conclusion: This study shows that the skin lesion, vulvodynia, and pruitus caused by genital ulcer was improved after the Korean traditional treatment and it can be effective medical alternatives or options for genital ulcer patients.