• 한국지하수토양환경학회:학술대회논문집
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• 한국지하수토양환경학회 1999년도 추계학술발표회
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• pp.34-38
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• 1999

This paper investigated remediation options for contaminated sediments with heavy metals. Twenty three sediment samples were taken from three different depths of 0.5m, 1.5m and 2.5m. The concentration of Heavy metals Cu, Pb, and Hg were measured. The concentration of copper far exceeded the Sediment Quality Guideline in U.S.A and Interim Sediment Quality Guidelines in Canada. Therefore, remediation of the sediments is requried to protect the benthos. Two remediation options were suggested : dredging of the organic sediments as deep as about 85cm followed by surface covers with clean soil, and in-situ stabilization of tile sediments using lime or cement followed by surface cover with clean soil.

• 한국대기환경학회지
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• 제18권6호
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• pp.475-485
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• 2002

An analytical method was investigated for the meaiiurement of polychlorinated biphenyls (PCBs) and organochlorine pesticides (OCPs) concentrations in air samples. Procedures required for column chromatographic clean up. silicagel (stage I) and gel permeation chromatography (stage II), were discussed. Identification and quantification of PCBs and OCPs were performed using a combination of gas chromatography/mass spectrometry/ selected ion monitoring. Recovery tests calculated from six samples are 68∼137% for PCBs and 58∼130% for OCPs except for endrin aldehyde. Instrumental detection limits determined for the PCBs and OCPs varied from 0.05 to 0.18 pg/m3 and from 0.71 to 16.82 pg/㎥, respectively. The method has been applied to the analysis of air samples collected at Ansung city, Kyonggi province, Korea. This method may serve as a screening protocol for the simultaneous determination of PCBs and OCPs in air.

• 대한음성학회지:말소리
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• 제63호
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• pp.153-170
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• 2007

It is well known that when there is an acoustic mismatch between the speech obtained during training and testing, the accuracy of speaker verification systems drastically deteriorates. This paper presents the use of MFCCs' histogram enhancement technique in order to improve the robustness of a speaker verification system. The technique transforms the features extracted from speech within an utterance such that their statistics conform to reference distributions. The reference distributions proposed in this paper are uniform distribution and beta distribution. The transformation modifies the contrast of MFCCs' histogram so that the performance of a speaker verification system is improved both in the clean training and testing environment and in the clean training and noisy testing environment.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2009년도 춘계학술대회 논문집
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• pp.919-929
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• 2009

2008, Seoulmetro transports an average of 3,952,000 passengers every day with a 0.8% increase of the daily ridership compared to last year.(Korean Economics '09.01.21) Seoul subway systems ridden by a considerable number of Seoul citizens place their top priority on swiftness, safety and clean underground air quality so as to meet the customer satisfaction. One of the most important problems is to eliminate minute dust(PM10) among the pollutants such as the gas attributable to air pollution and floating particulate matter defined by the ordinance of the Ministry of Environment. Seoulmetro install and operate many kinds of air filtration facilities, however we've launched a research on "Standardization Plan on Underground Air Filtration Facility" for the installation and improvement of optimum standardized air filtration system. As a preliminary study, we're going to consider ventilation system and air filter to supply filtered metropolitan outdoor air aimed at ensuring clean underground environment.

• 한국분말야금학회:학술대회논문집
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• 한국분말야금학회 2006년도 Extended Abstracts of 2006 POWDER METALLURGY World Congress Part 1
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• pp.221-222
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• 2006

This paper describes a Plasma Assisted Debinding and Sintering (PADS) equipment, which has been designed to process Metal Injection Molded (MIM) components. The use of a hybrid system combining a glow discharge with a conventional heating system makes debinding and sintering of MIM components, in the same heating cycle, a feasible industrial process. Characteristics as density, carbon content and mechanical properties are similar to traditionally processed MIM materials. The reduction of energy and gas consumption and shorter lead-times are economic advantages of PADS system. The clean environment of PADS is also an ecological advantage.

• 자원ㆍ환경경제연구
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• 제21권3호
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• pp.627-681
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• 2012

본 논문은 독점적 경쟁과 내생적 성장의 모형으로 시작하여 생산과정에 투입되는 생산요소로서 오염을 추가했다. 그리고 환경의 질이 생산에 사용되는 재생가능한 자원인 것으로 채택했다. 본 논문은 생산요소로서 청정 활동의 분화에 기인하는 수확체증이 환경의 질을 해치지 않고 지속가능한 성장을 이끄는 데 도움을 줄 수 있다는 것을 보였다. 또한 오염과 독점적 경쟁으로부터 발생되는 두 가지 왜곡들을 교정할 수 있는 서로 다른 여러 가지 정책조합(조세 +보조금)을 비교하고 평가했다. 끝으로 본 논문은 최종재 생산에 있어 환경의 생산성이 충분치 않을 경우에 청정재의 수는 더 많은 환경적 우려와 함께 증가하는 경향이 있다는 것을 찾아냈다.

• 청정기술
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• 제2권2호
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• pp.165-175
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• 1996

절삭가공 공정에 있어서 절삭유제는 환경영향이 가장 큰 요인들 중의 하나이다. 현재의 기술수준에서 환경영향을 줄이기 위한 공정개선의 방법으로 유제의 환경부하에 대한 평가 및 저부하 유제로의 사용대체가 있다. 본 논문에서는 기존의 절삭성을 바탕으로한 절삭유제의 선택방법과 환경영향을 고려한 선택방법을 비교하여 절삭유제의 선택기준을 제시하고 환경부하의 평가방법으로 AMP 방법을 소개한다. 중절삭이며 저속가공인 드릴링가공을 통하여 절삭성과 환경영향을 함께 고려한 절삭유제의 선택과정을 예시한다. 절삭가공의 물질수지를 고려하여 다섯가지의 환경영향의 평가요소를 선정하고 한국공업규격의 다섯가지의 절삭유제를 비교한다. 비수용성 절삭유제가 성능 뿐만 아니라 환경적인 면에서도 수용성 유제에 비하여 우수한 결과를 보여주었다.

• 대한설비공학회:학술대회논문집
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• 대한설비공학회 2008년도 동계학술발표대회 논문집
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• pp.452-457
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• 2008

We performed a study on the contaminant transfer in a clean space for the location of product and fan filter unit using computational fluid dynamics analysis. To simplify the real product moving process, three different non-moving cases regrading the locations of product were selected: no product, at the lower side, and at the upper and lower sides. And to investigate the characteristics of the contaminant transfer, the arrangement of fan filter units was varied. Local mean air-age and contaminant distribution were used as evaluation indices. From the results, the contaminant transfer to the product was the most when the products were simultaneously located at the upper and lower sides. And the contaminant was easily exhausted regardless of the location of product when the fan filter units were properly arranged at the top side of the clean space.

• 설비공학논문집
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• 제21권5호
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• pp.273-281
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• 2009

In recent semiconductor manufacturing clean rooms, the energy consumption of outdoor air conditioning systems represents about 45% of the total air conditioning load required to maintain a clean room environment. Meanwhile, there is a large amount of exhaust air from a clean room. From an energy conservation point of view, heat recovery from the exhaust air is therefore useful for reducing the outdoor air conditioning load for a clean room. In the present work, an energy-efficient outdoor air conditioning system was proposed to reduce the outdoor air conditioning load by utilizing an air washer to recover heat from the exhaust air. The proposed outdoor air conditioning system consisted mainly of a preheating coil, an air washer, two stage cooling coils, a reheating coil, a humidifier and two heat recovery cooling coils inserted into the air washer and connected to a wet scrubber. It was shown from the lab-scale experiment with outdoor air flow of $1,000\;m^3/h$ that the proposed system was more energy-efficient for the summer and winter operations than an outdoor air conditioning system with a simple air washer.

• 한국환경보건학회:학술대회논문집
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• 한국환경보건학회 2006년도 Perspectives of Evironmental Health Issues in Asia-Pacific Region
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• pp.111-122
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• 2006