• 제목/요약/키워드: Impact Reduction

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바닥 상부 마감재의 충격음 저감성능에 대한 평가방법 개선 (Improvement of evaluation method for impact sound reduction performance of floor coverings)

  • 정진연;송한솔;송국곤;윤용진
    • 한국음향학회지
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    • 제42권2호
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    • pp.161-167
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    • 2023
  • 최근 바닥충격음 사후 성능검사 제도의 시행에 따라 공동주택 바닥 슬래브 상부에 설치되는 바닥 마감재에 대한 바닥충격음 성능 개선의 요구사항은 증가하고 있다. 하지만 현재의 KS F ISO 717-2 및 KS F 2863에서의 바닥 마감재 성능 평가방법은 완충층이 설치되지 않은 조건에서 저감량을 측정하는 것으로 되어 있다. 준공 전 성능측정 의무화로 인해 본인이 거주하는 공동주택 바닥충격음 성능의 확인이 가능한 상황에서 입주민이 거주하는 공동주택의 특성을 반영하는 온돌층이 설치된 구조에서의 성능평가는 마감재의 바닥충격음 성능에서 더 필요한 부분일 것이다. 따라서 본 논문에서는 바닥슬래브 상부 마감구조의 저감량 평가를 위해서 완충층 조건을 포함한 저감성능 평가를 제안하고, 완충층 성능에 따른 저감량의 차이를 확인할 수 있도록 마감재가 설치되지 않은 상태의 바닥충격음 성능을 동시에 표시하는 것을 제안한다.

포름알데히드로 오염된 실내공기의 정화에 미치는 식물효과에 관한 연구 (A Study on Plant Effects on Decontamination of Polluted Indoor Air with Formaldehyde)

  • 박소영;김정;장영기;성기준
    • 환경영향평가
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    • 제14권4호
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    • pp.147-155
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    • 2005
  • This study was designed to investigate the effect of plant as a botanical air purification on the indoor pollution by formaldehyde. Three indoor plants such as Dracaena marhginata, Spathiphyllum and Dracaena reflexa, were placed in the artificially contaminated reactor under laboratory condition. Both plant and soil effects on removal of formaldehyde from contaminated indoor air were observed. Reductions in the formaldehyde levels appeared to have been associated with soil medium factors as well as plant factors. The effect of soil on formaldehyde reduction was high in the early stage of the experiment and the results suggest that sorption could be more important factor than microbial degradation in the initial dissipation of contaminants in the soil. It was suggested that the effect of plant on formaldehyde reduction might be related to the plant species, total leaf surface area of plant, degree of contribution of soil medium, and exposed concentration level. The results of this study showed that air purification using plants is an effective means of reduction on indoor formaldehyde level, though, utilization of soil media with high sorption capacity and/or supplementary purifying aids were also suggested when the source is continuous or exposed concentration level is high.

한.인도 CEPA 수출입유망품목의 효과 연구 - 2010년 수출입실적을 중심으로 - (A Study on the Efficacy for Promising Ex-Importable Items of CEPA between Korea & India - Focused on the Ex-Import Performance in 2010 -)

  • 임목삼
    • 무역상무연구
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    • 제49권
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    • pp.545-566
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    • 2011
  • This paper study on the effect of the removal or reduction of the tariff on Korea-India trade by CEPA between Korea & India and then examines the effects of increased exports & imports to Korea on India. Despite the analysis is based on data over a short period of time, this paper shows that CEPA between Korea & India has substantially increased Korean exports(42.7%) and imports(37%) to India in 2010. It is also shown that CEPA between Korea & India has had a considerable impact on market. As a result can be summarized as follows. The potential fields of expanding the trade between the two countries due to the tariff concessions of the removal or reduction. Consequently the effect of the removal or reduction of tariff will be low our expectation but CEPA between Korea & India would have a positive effect on Korea's exports to India in the long term. This paper has examined the impact of CEPA between Korea & India on general economy. It needs a further study to estimate trade diversion effect of CEPA and to find out the impacts on specific industry.

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Arc-Groove를 가진 D-형상 물체 주위 유동에 관한 연구 (A Study on the Flow around a D-shape Bluff Body with Arc-Groove)

  • 서성호;남청도;이형우;홍철현
    • 한국유체기계학회 논문집
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    • 제17권6호
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    • pp.59-63
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    • 2014
  • Object of this study is to see whether the arc-groove on a D-shape bluff body effects the drag reduction or not. To this end, the changes of the boundary layer on the surface of the object, the downstream flow field and wake flow were found by experiments. The experiments are conducted by changing number and depth of the groove, angle of the first groove and Reynolds number(Re). Groove did not effect on the surface in the downstream boundary layer of the object and was minimal impact on the time mean velocity recovery of the wake flow. Also the effects of Groove did not have a significant impact on the structure of the wake and the wake frequency. Therefore it is found that the arc-groove of the drag reduction effect on the D-shape bluff body was smaller.

중국의 오염저감 정책이 이산화황 배출에 미치는 영향 분석 (An Analysis of the Impact of China's Pollution Reduction Policy on Sulfur Dioxide Emissions)

  • 김가영;이재승
    • 한국기후변화학회지
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    • 제6권4호
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    • pp.367-377
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    • 2015
  • This study analyzed the effectiveness of China's policy to reduce of sulfur dioxide. China's $12^{th}$ Five-year plan on national economic and social development emphasized environmental protection and low-carbon economic development. Sulfur dioxide was one of the major gases to affect air pollution and climate change and its control became a key policy agenda in the environment and energy sector. As the absolute amount of sulfur dioxide emissions in China came from the industrial sector, the control of the coal-based energy was especially urgent. This study analyzed the factors that influenced the sulfur dioxide emissions and the policy effects to reduce sulfur dioxide in China from 2003 to 2012 based on regional data. The air pollution treatment investments showed the biggest impact together with energy conservation policy in reducing sulfur dioxide emissions. However, pollutant emissions charge did not show a relevant policy effectiveness in all regions as the amount of charge would be smaller than economic benefit from non-compliance. Rationalizing pollutant emissions charge is, therefore, a key policy task for further reduction of sulfur dioxide emissions.

수도권 지역별 목표대기질 달성을 위한 오염배출 삭감율 산정 연구 (An Estimation of Emission Reduction Rates to Achieve the Target Air Quality in Seoul Metropolitan Area)

  • 김정수;김지영;홍지형;정동일;반수진;박상남
    • 환경영향평가
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    • 제16권1호
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    • pp.1-13
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    • 2007
  • This study was carried out to estimate the emission reduction rates for the regional allowable emissions by special measures to achieve the target air quality in Seoul Metropolitan Area (SMA). A modeling system was designed to validate the details in enforcement regulations set up by local governments based on the current status and plans for air quality improvement. Modeling system was composed of meteorological model (MM5), emission model (SMOKE), and air quality model (CMAQ). Predicted results by this system show quiet well not only daily air pollutants concentration but also the tendencies of wind direction, wind speed and temperature. To achieve the target air quality in Seoul Metropolitan Area (SMA), emission allowances are estimated by seasons and regions. Referring to the base year 2002, it was estimated that emission reduction rates to achieve the intermediate goal in 2007 were 14.2% and 16.6% for NOx and $PM_{10}$, respectively. It was also estimated that 52% of NOx and 48% of $PM_{10}$ reductions from the base year 2002 would be required to accomplish the air quality improvement goal of 22 ppb for $NO_2$, and $40mg/m^3$ for $PM_{10}$ in year 2014. To improve $NO_2$ and $PM_{10}$ concentration through emissions reduction policies, it was found that emissions reduction for the on-road mobile sources would be the most effective in SMA.