• 제목/요약/키워드: Indoor noise

검색결과 430건 처리시간 0.028초

국내 일부학교 건축물의 실내공기질 평가 (The Assessment of Survey on the Indoor Air Quality at Schools in Korea)

  • 손종렬;노영만;손부순
    • 한국환경보건학회지
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    • 제32권2호
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    • pp.140-148
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    • 2006
  • Recently, indoor air quality (IAQ) in workplace, residential environments and schools has been concerned of people, scientists and related the public, and has recognized the health effects related to indoor air pollution. Therefore, this study was performed to investigate the characteristics of IAQ in 55 kindergartens, elementary school, middle schools, and high schools from June, 2004 to May, 2005 in Korea. We measured indoor air pollutants($PM_{10},\;CO_2$, HCHO, total bacteria colony(TBC), CO, radon, TVOCs, asbestos, and $O_3$), and physical factors(noise, temperature, relative humidity, and illumination) with necessary of management for IAQ in school. We classified into 5 kinds of the school by period since building completion, <1 year, 1-3 years, 3-5 years, and 5-10 years. The concentration of pollutants and the level of physical factors compared with standards and guidelines of IAQ on the Ministry of Environment, the Ministry of Health and Welfare, and the Ministry of Education and Human Resources Development. The major results obtained from this study were as follows. Temperature, relative humidity and illumination among the physical factors did not exceed the standards, but noise exceeded it. Asbestos and $O_3$ did not detect in surveyed classrooms. CO, TBC, TVOCs, and HCHO in kindergartens, TBC in elementary schools, TBC, TVOCs dnd HCHO in middle schools, and HCHO in high schools detected the standards. This study is conducted as a part of efforts to provide a foundational data for further relative researches on management of IAQ of school. Therefore, we suggest that country plan for management of IAQ in school should be established through long-term and continuous investigation for assessment on IAQ in school and health risk assessment for students.

구내 데이터 통신용 무선모뎀 설계 및 구현 (Design and Implementation of Wireless Modem for Indoor Data Communication)

  • 조병학
    • 정보통신설비학회논문지
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    • 제11권1호
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    • pp.16-22
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    • 2012
  • Wireless data communication is easy to be affected by channel noise and degrade reliability and stability by the multipath fading and ISI compared with wired data communication. In this paper, we designed and implemented indoor wireless modem adopted DQPSK modulation scheme for improvement of bandwidth efficiency, and convolutional encoding, Viterbi decoding and hybrid ARQ algorithm combinig FEC with CRC for efficient error control in indoor wireless channel. Testing the implemented wireless modem, we verified the proposed scheme is proper to efficient and reliable indoor wireless data communication.

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어린이집 보육공간의 실내환경 및 공간위생 관리실태 - 청주시를 중심으로 - (Management Condition on Indoor Environment and Hygiene of Childcare Center -Focusing on Cheongju-)

  • 최윤정
    • 한국가정과학회지
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    • 제9권2호
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    • pp.5-20
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    • 2006
  • This study was a preliminary investigation into improving the environmental and healthy quality of childcare centers. The purpose of this study was to determine the management condition on indoor environment and hygiene of childcare centers in Cheongju. Questionnaire survey was carried out from 11st to 26th of August 2004 by mail. Respondents were consisting of 55 teachers, an executive of each childcare center in Cheongju. From the survey results, there were some problems in 'empty period after remodeling work for preventing sick house syndrome', 'humidity controling', 'glare controling', 'indoor or outdoor noise controling', 'cleaning frequency of each room', 'washing method of toys', 'laundry frequency of rag doll and bedclothes'. So, we need to establish the regulations or give some educations and informations about indoor environment and hygiene to administrators of childcare centers.

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예인 음탐기 콘솔의 냉각 배출 홴 소음 저감을 위한 소음기 개발 (Development of the Silencer for Reducing Noise from the Exhaust Cooling Fan of the TASS Console)

  • 한형석;박미유;조흥기;김중길;임동빈;손윤준
    • 한국소음진동공학회논문집
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    • 제20권12호
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    • pp.1139-1146
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    • 2010
  • The indoor noise of the naval vessel is very important related to the optimum environmental conditions for crews as well as the ability of fighting power of antisubmarine. Especially, sonar equipment room is one of the rooms where require to be silent because the informations of the underwater noise are collected and analyzed in there. In this paper, the sound reduction of the TASS console, one of the main noise sources in a sonar equipment room for a typical naval vessel, is described. The noise source of this TASS console is the flowing noise of cooling fan. In order to reduce this kind of noise, the plenum chamber and acoustic elbow were developed. Related to the development of the plenum chamber, the area of the air-outlet and sound absorption of the inner lining were investigated experimentally with the evaluation system of the sound insertion loss. Acoustic elbow was also manufactured and evaluated with the evaluation system of the sound insertion loss. Finally, in order to evaluated the ability of noise reduction of the plenum chamber and acoustic elbow, the indoor noise of the sonar equipment was measured when they were appled to TASS console.

가변위치 고음성인식 기술을 이용한 무선 홈 네트워크 시스템 구현에 관한 연구 (A Study on the Realization of Wireless Home Network System Using High-performance Speech Recognition in Variable Position)

  • 윤준철;최상방;박찬섭;김세영;김기만;강석엽
    • 한국정보통신학회논문지
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    • 제14권4호
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    • pp.991-998
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    • 2010
  • 실내 환경에서 음성인식 기술을 이용한 무선 홈 네트워크 시스템 구현에 있어, 잡음과 실내 잔향음은 시스템 성능 저하의 주요 원인이다. 본 연구에서는 실내 인식환경에서 스펙트럼 엔트로피(Spectral entropy) 기반의 음성 구간검출법을 이용하여 잔향음(reverberation) 및 실내잡음에 강인한 음성인식 홈 네트워크 시스템을 구현하고자 한다. 스펙트럼 차감법(Spectral Subtraction)은 잔향으로 인해 왜곡된 신호를 스펙트럼 상에서 제거하여 잔향의 효과를 줄일 수 있고 음성신호와 독립적인 잡음을 제거 할 수 있다. 효과적인 스펙트럼 차감을 위해서는 음성과 비음성 구간의 정확한 구분이 수반되어야 하며 이를 위해서 엔트로피 기반의 음성 구간 검출법을 적용하여 성능을 향상시킨다. 모의 및 실내환경 실험 결과 Spectral entropy 기반의 음성 구간 검출법을 이용할 경우 실내 잔향 및 잡음환경에서 명령어 인식률의 향상이 증명되었다.

실내 소음기준 설정에 관한 실험적 연구 -동일 건물내 사업장을 중심으로- (An Experimental Study on the Establishment of Indoor Noise Criteria - Focused on Korean Complex Building-)

  • 이태강;국찬;장길수;김선우
    • 한국소음진동공학회:학술대회논문집
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    • 한국소음진동공학회 2008년도 춘계학술대회논문집
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    • pp.9-12
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    • 2008
  • There are many place of business in complex building, and recently claims of noise have increased in those buildings. It is most desirable reducing the noise problems to establish the noise criteria considering the noise source and the receiving place of business, which are derived from the dose-response of noise and results of the actual condition. The degree of response to the transmission noise could be changed with background noise level in the receiving stores. In this research, the subjective evaluation for three different background level in receiving place of business or rooms were investigated from subjective tests. The eight business sound source including aerobic music were used for the test.

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