• 제목/요약/키워드: smog

검색결과 123건 처리시간 0.024초

스모그 챔버에서 수분 반응에 의한 대기 에어로졸의 생성 및 성장 (Formation and Growth of Atmospheric Aerosols by Water Vapor Reactions in an Indoor Smog Chamber)

  • 김민철;배귀남;문길주;박주연
    • 한국대기환경학회지
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    • 제20권2호
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    • pp.161-174
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    • 2004
  • Aerosol formation and growth by water vapor reactions were investigated in a 2.5 -㎥ indoor smog chamber filled with the unfiltered ambient air. The relative humidity of test ambient air was elevated at 59~64% or 84~88% by adding water vapor. The aerosol number size distribution and the concentrations of $O_3$, NO, NO$_2$, and SO$_2$ were measured during the experiments. The $O_3$ and NO$_2$ gases were well reacted with the water vapor at high relative humidity of 84~88%, and the reaction rates of these gases seemed to be decreased at low relative humidity of 59~64%. The formation and condensational growth phenomena of ambient aerosols by water vapor reactions were observed in a Teflon bag, depending strongly on the initial particle size distribution. The water vapor reactions might be affected by the contents of oxidants produced by photochemical reactions under sunlight.

Topic Modeling을 이용한 Twitter상에서 스모그 리스크에 관한 대중 인식 분류 연구 (Classification of Public Perceptions toward Smog Risks on Twitter Using Topic Modeling)

  • 김윤기
    • 지적과 국토정보
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    • 제47권1호
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    • pp.53-79
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    • 2017
  • 본 연구의 주된 목적은 토픽 모델링(topic modeling)을 이용하여 트위터 상에서 스모그 리스크(smog risks)에 관한 대중 인식(public perceptions)을 측정하고 분류하는 것이다. 선행연구에 있어서 연구 갭(research gap)을 확인하기 위하여 본 연구는 스모그 리스크와 토픽 모델링에 대한 선행연구를 검토하였다. 그 결과 본 저자는 기존의 연구에서 상당한 연구 갭이 존재하고 있음을 확인하였으며, 이러한 연구 갭을 메우기 위해 다섯 개의 연구 질문을 설정하였다. 연구 질문들에 답을 구하기 위하여 본 연구는 10,000개의 트위터 자료를 추출하였고, 이에 대하여 워드 클라우드 분석(word cloud analysis), 상관분석, LDA를 이용한 토픽 모델링, 스트림그래프(stream graph), 위계적 집락분석(hierarchical cluster analysis)을 실시하였다. 분석 결과 자주 언급되는 단어들(the most frequent terms), 단어네트워크(terms network)의 형태, 상관관계의 유형, 스모그 관련 주제의 변동패턴에 있어서 뉴욕과 런던 사이에 큰 차이가 있음을 확인하였다. 그리하여 본 저자는 다섯 개의 연구 질문 중 네 개에 대하여 긍정적인 답을 구할 수 있었고, 이를 토대로 몇 가지 정책적 시사점을 제시하고, 향후 연구를 위한 제안들을 하였다.

철도 터널 단면적에 따른 연기 전파 연구 (A study of smog diffusion when a fire takes place in tunnels)

  • 박병은;이종일;남명식;김동기;김선홍
    • 한국철도학회:학술대회논문집
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    • 한국철도학회 2005년도 춘계학술대회 논문집
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    • pp.633-639
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    • 2005
  • We studied three dimension numerical analysis in the case that a train stops in tunnels by fire. And the 'Fluent 6.1' which is CFD(Computational Fluid Dynamics) program was used in this study. We compare the smog diffusion in single/double track ordinary railway tunnels with that in double track high speed railway tunnels in this study.

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일본 동경소방청의 피난안정성평가 시뮬레이션 기술개발 사례연구 (A Investigation Study on the Development of Egress Simulation for Evacuation Safety Evaluation of Tokyo Fire Dept. Department in Japan)

  • 이현진;서동구;권영진
    • 한국화재소방학회:학술대회논문집
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    • 한국화재소방학회 2008년도 추계학술논문발표회 논문집
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    • pp.216-222
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    • 2008
  • A large number of Computer-based fire growth and Evacuation model have been developed for various purpose and many of these are widely used for research and engineering. And Most of Egress simulation program are ordinary case only related to human behavior But Egress safety Evaluation is very closed to smog movement. It is well known that the Egress simulation program made by Tokyo Fire Department are related to smog movement. So It is the aim of this study to investigate on the Development of Egress Simulation for Evacuation Safety Evaluation of Tokyo Fire Dept. Department in Japan.

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초(初).중등교육시설(中等敎育施設)의 실내쾌적성(室內快適性) 평가(評價) 우리나라 대표적(代表的) 건축(建築) 사례(事例)를 중심(中心)으로 (An Evaluation of School Building Systems with respect to Students' Comforts in the Class Room in Korea)

  • 민창기
    • 교육시설
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    • 제2권3호
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    • pp.31-38
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    • 1995
  • The paper is to evaluate existing school building system with respect to students' comforts in the class room in Korea. This paper compared three styles of different school building system builted during last 20 years. Using statistical analysis, at first, the paper found that box-style structure is efficient for sustaining heat in the class room because it is compactly constructed. Secondly, air conditioning in the class room is important factor affected students' comforts in the summer time and for the smog occurring in the heating class room. Thirdly, we should compactly construct school building because the compactiveness of building components is important factor for student comforts. Fouthly, heating system in the class room should be changed. The system using gas or electricity insteded of coals should be introduced in the class room for the smog of the stove in winter time and for freshness in summer time.

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Aerosol Wall Loss in Teflon Film Chambers Filled with Ambient Air

  • Lee Seung-Bok;Bae Gwi-Nam;Moon Kil-Choo
    • Journal of Korean Society for Atmospheric Environment
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    • 제20권E1호
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    • pp.35-41
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    • 2004
  • Aerosol wall loss is an important factor affecting smog chamber experiments, especially with chambers made of Teflon film. In this work, the aerosol wall loss was investigated in 2.5 and $5.8-m^3$ cubic-shaped Teflon film chambers filled with ambient air. The natural change in the particle size distribution was measured using a scanning mobility particle sizer in a dark environment. The rate of aerosol wall loss was obtained from the deposition theory suggested by Crump and Seinfeld (1981). The measured rates of aero-sol wall loss were In a good agreement with the theoretical and experimental values given by McMurry and Rader (1985), implying that the electrostatic effect enhances particle deposition on the chamber wall. The significance of aerosol wall loss correction was demonstrated with the photochemical reaction experiments using the ambient air.