• Proceedings of the Korea Water Resources Association Conference
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• 2008.05a
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• pp.827-831
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• 2008

In this study, the effects of reclaimed wastewater irrigation on the concentration of heavy metals such as lead, zinc, cadmium, and copper in soil and vegetables were investigated by monitoring an experimental area irrigated with reclaimed wastewater. Three treatments and three replications on $10{\times}2$-m plots were installed and heavy metal concentrations in soil and vegetables were monitored from 2005 to 2007. The treatments applied in this study were groundwater irrigation (control treatment), wastewater irrigation, and irrigation with filtered reclaimed wastewater treated with ultraviolet light. The monitored results showed that the concentrations of Cu, Cd, and Pb in soil during the experimental period were lower than initial soil levels before irrigation, whereas Zn increased in all treatment plots. However, the ranges of Zn, Cu, Cd and Pb in soil were below the soil pollution standards in the Republic of Korea. Heavy metal concentrations in vegetables showed insignificant variations for all treatments.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.6 no.1
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• pp.57-61
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• 2007

Special quality of automobile clutch master cylinder(CMC) and analyzed aluminum, plastic material comparison. Efficiency of plastic master cylinder can modularize higher, light weight anger of parts, several piece parts by single parts, prove NVH(Noise, Vibration, Harshness) than aluminum master cylinder as analysis result. Also, structure is easy simplicity, exchange, maintenance costs can be reduced and decrease environmental pollution because recycling is superior. According as content of glass fiber increases, mechanical properties of matter of material increase equally and glass fiber changed variously by condition on manufacturing process. Through comparison analysis with Plastic body development connection site, did verification.

• Journal of Power System Engineering
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• v.12 no.6
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• pp.83-87
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• 2008

EPS(Electric Power Steering) system, which has replaced the hydraulic steering system(HPS or HPAS) in many passenger cars recently, have many merits such as low energy consumption, easy mounting, light weight and improvement of environmental pollution. However, EPS system has the problem of motor noise when motor is rotated, which can make a driver feel uncomfortable. There are many techniques to solve those problems, but they are not clear. It is necessary to evaluate the mechanical noise in steering systems, because an EPS has vibration sources such as at the motor gear reducer, manual gears and intermediate joints. In this paper, reduction technique of EPS motor noise is introduced.

• Proceedings of the Korea Committee for Ocean Resources and Engineering Conference
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• 2000.10a
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• pp.123-128
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• 2000

The ocean is now increasingly suffering from pollution mainly caused by oil spill accidents roil increasing marine transportation. It cause not only the deterioration of ocean resources but also critical damage on the ocean ecosystem. Present study is an experimental one for the development of the oil skimmer which can collect spilled-oil actively and effectively from the sea surface. As an effort of achieving it, a new type of water wheel attached nil skimmer was devised, based upon the concept of orifice. The shapes of the water wheel, blades and oil storing tank are found to be very important factors on the oil skimming performance through systematic experimental analysis. Real oil recovery test was also carried out in square tank using the oil skimmer with their optimal shapes. Quite satisfactory result are obtained from the test which showed 99% and 98% recovery rates for light oil and heavy oil in still water condition, respectively.

• Proceedings of the Korean Environmental Sciences Society Conference
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• 2003.11a
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• pp.69-72
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• 2003

The meteorological model, CALMET, and its plume dispersion model, CALPUFF, were used in order to simulate the dispersion of $SO_2$ emitted from Yatagan Power Plant and its effect on Yatagan district in the episodic event on December 2 and 3, 2000. It is found that south westerly and light winds and the nighttime surface inversion layers lead to accumulation of pollutants over Yatagan district. The results are compared with the measurements done by Local Environmental Authorities of Mu la. The simulation results indicate that the maximum ground level concentrations were found northeast from the source, which agrees with experimental measurement. On the other hand, the magnitude of results obtained with the model shows some differences compared with experimental measurements.

• Proceedings of the Korea Air Pollution Research Association Conference
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• 2003.11a
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• pp.243-244
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• 2003

오존은 매우 불안정한 물질로서, 기타의 환경 대기 가스 분석법에서와 같이 해당 성분의 측정기를 표준 가스로 교정한 후 분석할 수 없다. 이러한 이유로, 환경 대기 중의 오존을 분석하는 일반 분석기의 교정을 목적으로, 본 연구실에서는, 국가 일차 오존 표준분광기(O$_3$-SRP)를 제작하여 운영하고 있다. 운영되고 있는 $O_3$-SRP의 측정 원리는 자외선 흡광 광도법이며, 농도값의 결정은 순수하게 Beer-Lambert 법칙에 따른다. Beer-Lambert 법칙에 따라서 오존 농도를 절대적으로 측정하기 위해서는 몰 흡광계수, 광로의 길이, 투과도, 온도 및 압력을 정확히 측정하여야 한다. (중략)

• Proceedings of the Korea Air Pollution Research Association Conference
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• 2003.11a
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• pp.239-240
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• 2003

스모그 챔버는 대기 중 성분들의 화학 반응 기작을 연구하는데 사용되고 있다. 그러나, 기존 연구에서는 광화학 반응 전구물질의 농도가 실제 대기 농도보다 높고, 청정 공기에 연구 대상 전구물질만을 주입한 단순 혼합물을 이용하였으며, 여러 날에 걸쳐 반응이 진행된 성분들을 이용하지 않았다 (Dodge, 2000). 이와 달리 본 연구팀에서는 실내 스모그 챔버에 실제 대기를 도입하여 광화학 반응 실험을 수행하고 있다 (배귀남 등, 2003). 한 개의 스모그 챔버를 이용하는 경우 외기의 특성상 매 실험마다 초기조건이 달라지기 때문에 단일 인자의 차이에 따른 영향을 파악하기가 쉽지 않았다 (배귀남 등, 2003b). (중략)

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2001.11b
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• pp.296-299
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• 2001

Data on the oil spill recovery from the water surface by light floating electromagnetic plants using a new magnetic adsorbent are given. The feasibility scope for further oil recovery from such gathered mixtures(oil + adsorbent), reuse of this magnetic adsorbent and its property reclaiming and recycling were shown. The basic conception of the oil spill recovery and efficiency of this method were set forth.

• Proceedings of the KIEE Conference
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• 1997.07a
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• pp.303-305
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• 1997

The advantage of application polymer instead of conventional porcelain as the housing material for arrester is that light weight, shorter section length of arrester would be possible due to the use of an insulated hanger (mold compound). also, polymer arrester has very good characteristics in design versatility as well as excellent resistance to moist ingress and pollution performance. The finite element method is widely used to calculate for electromagnetic devices. In this paper, we perform the each conditional analysis of PC with an advanced graphical user interface(GUI) using the vector fields simulator. And we try to analyze electromagnetic fields through the conventional two dimensional analysis in case of high voltage contamination on the electrode of a arrester.

• Journal of Korean Society for Atmospheric Environment
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• v.9 no.E
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• pp.364-372
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• 1993

The purpose of this study is to analyze traffic patterns by use of TRANSYT-7F Model, and to choose the optimum traffic-light cycle length and cycle splite to improve traffic flow and air quality at Samsung Intersection in Seoul. Emission rates of air pollutants are calculated for three time segments 0700-0900, 0900-1800 and 1800-2000. The traffic volume correlated reasonably well with air pollutants emitted ; however, the phasing and timing of traffic signals was found to equally be important. The results of performance with optimal setting indicate that the best cycle length were 80sec(0700-0900), 95sec(0900-1800) and 90sec(1800-2000), res-pectively. As expected the highest emissions of air pollutants were observed during the evening rush hours (1800-2000). A properly designed signalized intersection can help reduce traffic delay, driver discomfort, fuel consumption, and air pollution by efficiently the capacity of existing intersection.