• Title/Summary/Keyword: Two microphone method

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Role of Print and Audiovisual Media in Cervical Cancer Prevention in Bangladesh

  • Nessa, Ashrafun;Hussain, Muhammad Anwar;Ur Rashid, Mohammad Harun;Akhter, Nargis;Roy, Joya Shree;Afroz, Romena
    • Asian Pacific Journal of Cancer Prevention
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    • v.14 no.5
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    • pp.3131-3137
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    • 2013
  • Background: Visual inspection of cervix with acetic acid (VIA) is offered at 252 centers in 64 districts of Bangladesh. VIA+ve women are managed at colposcopy clinics of Bangabandhu Sheikh Mujib Medical University (BSMMU) and 14 Medical College Hospitals (MCHs). This research work has been supported by 'UICC Cancer Prevention Campaign' programme. Objectives: This study explored the role of print materials and electronic media to improve cervical cancer screening in the present socio-cultural context of Bangladesh. Methods: This study was performed from January to August 2011 at two upazilas of Bangladesh (Singair with screening facility and Sonargaon without screening facility). Data were collected by focus group discussion (FGD) with women, husbands and community people before and after intervention. Information on cervical cancer screening and VIA camps was disseminated using advertisement through local cable line of the television, microphone announcement, service providers and leaflet throughout the week prior to a VIA camp. Three-day VIA camps were organized at the upazila health complex (UHC) of both upazilas. Quantitative data was gathered from women at the camps on source of information on VIA and the best method of awareness creation. Results: The population was aware of "cancer" and a notable number knew about cervical cancer. Baseline awareness on prevention and VIA was low and it was negligible where screening services were unavailable. Awareness was increased fourfold in both upazilas after interventions and half of the women and the majority of the community people became aware of screening and available facilities. Cable line advertisement (25.5%), microphone announcement (21.4%), and discussion sessions (20.4%) were effective for awareness creation on VIA. Television was mentioned as the best method (37.4%) of awareness creation. Conclusion: Television should be used for nation-wide awareness creation. For local awareness creation, cable line advertisement, microphone announcements and health education at Uthan Baithaks/ EPI sessions can easily be adopted by the government.

Sound Absorption Effects in a Rectangular Enclosure with the Foamed Aluminum Sheet Absorber (발포 알루미늄 흡음재를 이용한 단순 폐공간의 내부 음장 변화에 관한 연구)

  • 김상헌;손동구;오재응
    • Transactions of the Korean Society of Automotive Engineers
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    • v.6 no.3
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    • pp.177-186
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    • 1998
  • For the purpose of finding out the sound field characteristics in a cavity of a rectangular enclosure with foamed aluminum lining, analytical and experimental studies are performed with random noise input. Experimental method using two-microphone impedance tube measures the absorption coefficients and the impedances of simple sound absorbing materials. Measured acoustical parameters of the test samples are applied to the theoretical analysis to predict sound pressure field in the cavity. The sound absorp- tion effects from measurements are compared to prediction in both cases with and without foamed aluminum lining in the cavity of the rectangular enclosure.

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The Error Involved in the Equivalent Electroacoustic Circuit Approach for the Element of Straight Pipe in Multiple Layer Perforated Plate Systems (다중 다공판 시스템에서 직관요소에 대한 전기음향등가회로법의 오류)

  • 이동훈;권영필
    • Transactions of the Korean Society for Noise and Vibration Engineering
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    • v.13 no.3
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    • pp.180-185
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    • 2003
  • The equivalent electroacoustic circuit approach has been conventionally used for the analysis of the multiple layer perforated plate system. However, it is found that an analogy error has been involved in the equivalent electroacoustic approach proposed by previous researchers for the element of straight pipe. Although the pipe between the perforated layers is a distributed element in the analogy, it has been treated as a parallel element by previous investigators. The analogy error is demonstrated by comparing the calculated absorption coefficients based on the parallel circuit and the distributed circuit, respectively, with the measured values by the two-microphone impedance tube method.

A Study on the Sound Absorbing Performance of Parallel Perforated Plate Systems (병렬 다공판 시스템의 흡음성능에 관한 연구)

  • Hur, Sung-Chun;Lim, Jung-Bin;Ro, Sing-Nam;Lee, Dong-Hoon
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2002.11b
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    • pp.902-907
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    • 2002
  • An equivalent electroacoustic circuit approach of estimating the sound absorption coefficient for parallel perforated plate system is proposed. The proposed approach is validated by comparing the calculated absorption coefficients of a parallel single layer perforated plate system with the values measured by the two-microphone impedance tube method for various porosity and the number of perforated plate. The sound absorbing performances of parallel and series perforated plate systems are compared and discussed from a standpoint of frequency bandwidth with sound absorption. The proposed approach is further extended to the parallel double layer perforated plate system.

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Exhaust Noise Reduction of Dry vacuum Pump (건식진공펌프의 배기 소음 저감)

  • Ahn, Young-Chan;Lee, Hae-Jin;Lee, Jung-Yoon;Yang, Jung-Jik;Oh, Jae-Eung
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2007.05a
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    • pp.349-354
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    • 2007
  • This paper considers acoustic analysis of silencer within a Dry vacuum pump. Main object is noise reduction of Dry Vacuum Pump using the silencer. First, we measured SPL and Intensity for noise source identification and then, designed for the silencer corresponding with noise character. 4-pole parameter are used for predicting transmission loss which is one of characteristics of silencer when we designed for silencer. Calculated Transmission Loss to change main effective factor and selected to optimal value using Design of Experiment. Finally, noise reduction is estimated to compare existing silencer with optimal silencer.

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A Study on the Sound Absorbing Performance of Parallel Perforated Plate Systems (병렬 다공판 시스템의 흡음성능에 관한 연구)

  • Hur, Sung-Chun;Im, Jung-Bin;Lee, Dong-Hoon
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2002.11a
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    • pp.388.2-388
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    • 2002
  • An equivalent electroacoustic circuit approach of estimating the sound absorption coefficient for parallel perforated plate system is proposed. The proposed approach is validated by comparing the calculated absorption coefficients of a parallel single layer perforated plate system with the values measured by the two-microphone impedance tube method for various porosity and cavity depth. (omitted)

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Interior Noise Reduction of Enclosure Using Predicted Characteristics of Absorber (흡음재의 음향특성 예측에 의한 밀폐계의 내부 소음저감)

  • Lee Ghi-Youn;Sim Hyoun-Jin;Lee Jung-Yoon;Oh Jae-Eung
    • Journal of the Korean Society for Precision Engineering
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    • v.23 no.4 s.181
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    • pp.60-66
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    • 2006
  • For the purpose of finding out the sound field characteristics in a rectangular cavity, analytical and experimental studies are performed with white noise input. Two-microphone impedance tube method is used to measure the impedances of foamed aluminum. Foamed aluminum is well known metallic porous material which has excellent properties of light weight and high absorbing performance. And predicted impedances of foamed aluminum are compared with measured impedances. The predicted acoustical parameters are applied to the theoretical analysis to predict sound pressure field in the cavity. The measured sound absorption effects are compared with the predicted values for both cases with and without foamed aluminum lining in the cavity of the rectangular enclosure.

A Study on the Sound Absorptive Characteristics and Performance of Parallel Perforated Plate Systems (병렬 다공판 시스템의 흡음특성과 성능에 관한 연구)

  • Hong, Byung-Kuk;Song, Hwa-Young;Seo, Seong-Won;Lee, Dong-Hoon
    • Transactions of the Korean Society for Noise and Vibration Engineering
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    • v.15 no.9 s.102
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    • pp.1003-1008
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    • 2005
  • The acoustic absorption of a multiple layer perforated plate system is very good near the resonance frequency region, while it has been regarded as a demerit that its frequency bandwidth is considerably narrow. In order to overcome such a demerit, the parallel perforated plates with different porosities are proposed. The sound absorption of such system composed of a parallel perforated plate is calculated by an equivalent electroatoustic circuit approach and validated by comparing the calculated absorption coefficients with those measured by the two-microphone impedance tube method. The sound absorptive characteristics and performance of parallel perforated plate systems are discussed from a standpoint of frequency bandwidth related with sound absorption.

Flow Noise in the Outdoor Unit of an Air-conditioner (에어컨 실외기에서의 유동소음)

  • 이승배;이재환;김휘중;최진규;진성훈;박윤서
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 1997.04a
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    • pp.594-601
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    • 1997
  • Propeller fans are commonly equipped in outdoor units of air-conditioners to provide effective cooling in a dried heat exchanger. A new design technique was developed to satisfy requirements of aerodynamic and aeroacoustic performance, which employs the intersection method of two cylinders for mean camber line. Three proto-types of propeller fan including Palm-Shaped, Highly-Swept(PSHS) fan (proto 3)were not only to provide low lift forces for dipole sound, but also to reduce the organized tip vortices interacting with the fan guide causing narrow-banded rotating instabilities. Cross-correlation technique was applied to study flow noise source characteristics for three proto-type fans designed. The cross-correlations between a microphone at far field and a hot-wire sensor at near field show that flows near hub region of proto 3 fan are less organized and the flow structures especially at high flow rate coefficients for proto 3 fan are less correlated with noise generated than other proto-types fans.

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Exhaust Noise Reduction of Dry Vacuum Pump (건식 진공 펌프의 배기 소음 저감)

  • Ahn, Young-Chan;Lee, Hae-Jin;Park, Sang-Gil;Lee, You-Yub;Oh, Jae-Eung
    • Transactions of the Korean Society for Noise and Vibration Engineering
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    • v.17 no.10
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    • pp.950-957
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    • 2007
  • This paper considers acoustic characteristics of silencer within a dry vacuum pump. The main objective is to reduce noise in dry vacuum pump using the new designed silencer. First, SPL and sound intensity are measured for noise source identification and the new model silencer is designed corresponding to noise characteristics. 4-pole parameters are used to predict the transmission loss which is one of the interest characteristics of the new silencer. The calculated transmission loss is then used to change main effective factor and optimal value is selected by using design of experiment. By conducting an experiment, it is proved that the new designed silencer has reduced noise level by 6 dB(A) more than the original one.