• 한국소음진동공학회논문집
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• 제18권7호
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• pp.741-745
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• 2008

Residents in an area where both trains and cars pass through are exposed to not only road traffic noise but also railway noise. Nevertheless, the degree of annoyance the caused to the residents is being under evaluated as the noises have been evaluated separately. Therefore, this study aimed at evaluating the integrated noise of road traffic and railway, and proving the accuracy of the evaluation result.

• 한국환경보건학회지
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• 제34권5호
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• pp.395-402
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• 2008

Road traffic noise causes considerable disturbance and annoyance in exposed inhabitants. Particularly, arterial road noise is a significant environmental problem in many urban areas in which higher traffic volume and higher car speed occur. Arterial road noise became the target of this investigation in Seoul, South Korea. Noise levels were measured at four points that were based on distance from roadside at the same measurement site and under the conditions as reported by the National Institute of Environmental Research (NIER) in 1999. The average noise levels ($L_{eq,1h}$) of the arterial road was 80.3 dBA at 5 m, 77.4 dBA at 10 m, 73.7 dBA at 20 m, 70.9 dBA at 30 m. A comparison between 1999 and 2008's measurement values has shown that in 2008 noise level is up by about 1.5 dBA, traffic volume has increased by about 15.7%, while car speed has decrease by about 8%. The relationship between 2008' measured values and predicted values using the NIER Equation is low under 10 m from the roadside. The influence range of arterial noise is calculated at 26 m for road noise limits in daytime. In relation to the comparison between traffic volume and noise level, the equivalence in traffic volume (Light car+10xHeavy car) is higher than other variables.

• Safety and Health at Work
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• 제11권2호
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• pp.199-206
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• 2020

Background: In a wide range of industries, noise-induced hearing loss remains one of the most prevalent occupational problems. This study aimed to assess the noise exposure level and associated factors of hearing loss among textile workers in Yangon Region, Myanmar. Methods: A cross-sectional study was conducted at a Textile mill (Thamine), Yangon Region, from April to December 2018. In total, 226 workers who were randomly selected from 3 weaving sections participated in face-to-face interviews using a structured questionnaire. A digital sound level meter and pure-tone audiometer were used for the assessment of noise exposure level and hearing loss, respectively. Logistic regression analysis was performed to assess the associated factors of hearing loss. Results: In total workers, 66.4% were exposed to ≥85 dB(A) of noise exposure, and the prevalence of hearing loss was 25.7%. Age ≥35 years, below high school education, hearing difficulty, tinnitus, hypertension, > 9 years of service duration in a textile mill were positively associated with hearing loss. After adjusting confounding factors, age ≥35 years (adjusted odds ratio = 6.90, 95% confidence interval = 3.45-13.82) and tinnitus (adjusted odds ratio = 2.88, 95% confidence interval = 1.13-7.37) were persistently associated with hearing loss. Conclusion: Providing occupational hazard education and enforcement of occupational safety regulations should be taken to decrease the noise exposure level. The regular audiometry test should be conducted for assessment of hearing threshold shift. The employer needs to implement a hearing conservation program in workplace when noise exposure reaches or exceeds 85 dB(A) for 8 hours.

• 한국환경보건학회지
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• 제45권6호
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• pp.569-576
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• 2019

Objectives: The main purpose of this study was to assess firefighters' daily personal noise exposure and explore noise levels related to specific tasks and their contributions to total noise exposure using 24-hour full-shift noise exposure measurements with task-based data. Methods: Noise exposure was assessed for eight firefighters (two rescuers, two drivers, and four suppressors) using time-activity diaries. We collected a total of 24 full-shift personal noise sample sets (three samples per a firefighter). The 24-hour shift-adjusted daily personal noise exposure level (L_ep,d), eight weekly personal noise exposures (L_eq,w), and 40 task-specific L_eq values (L_{eq activity}) were calculated via the ISO/NIOSH method. Results: The firefighter noise-sample datasets showed that most firefighters are exposed to noise levels above EU recommended levels at a low-action value. The highest noise exposure was for rescuers, followed by drivers and suppressors. Noise measurements with time-at-task information revealed that 82.3% of noise exposure occurred when checking equipment and responding to fire or emergency calls. Conclusions: The results indicate that firefighters are at risk of noise-induced hearing loss. Therefore, efforts at noise-control are necessary for their protection. This task-specific noise exposure assessment also shows that protective measures should be focused on certain tasks, such as checking and testing equipment.

• Journal of Preventive Medicine and Public Health
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• 제35권3호
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• pp.205-213
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• 2002

장기간의 소음노출에 의한 혈압상승 또는 고혈압의 발생에 대해서는 많은 연구에도 불구하고 결과가 다양하고 논란이 많은 실정이다. 이에 연구자는 혈압에 대한 소음의 영향을 보다 정확히 평가하기 위해서 일개 사업장을 대상으로 유사 노출군의 코호트를 구성하고 9년간의 추적조사를 실시하였다. 여기서 얻은 자료를 이용하여 소음노출수준별로 혈압의 연도별 변화경향을 파악하고, 혼란변수를 통제한 상태에서도 혈압의 변화에 대해 소음노출이 영향을 미치는가를 파악하고자 하였다. 부산지역의 일개 금속제품 제조업에서 근무하고 있는 530명의 남자 근로자를 1991년부터 1999년까지 혈압을 9년간 매년 계속 추적조사 하였으며, 조사 대상자들을 근무여건과 노출되는 소음수준(noise level category, 이하 NLC로 약함)에 따라 NLC-I (사무실 근로자, 60dB(A) 미만으로 노출, 155명), NLC-II(현장 기술지원자 및 검사원, 소음에 비정기적으로 노출, 75명), NLC-III (현장근로자, 85 dB(A)이하로 노출, 귀마개 또는 귀덮개를 착용, 167명), NLC-IV (현장근로자, 85 dB(A) 초과 노출, 귀마개와 귀덮개를 동시에 착용, 133명) 의 4군으로 구분하였다. 추적기간동안 소음수준별 혈압은 분산 분석을 이용하여 비교하였고, 혼합선형모형을 이용하여 추적기간동안(1992-1999년)의 보정된 통합평균혈압을 구하고 소음노출수준별로 비교하였다. 고려된 혼란변수는 기준연도(1991년)의 연령, 흡연여부, 음주량, 운동, 고혈압 가족력, 수축기 및 확장기 혈압과 체질량지수의 변화였다. 기준연도의 혈압과 혼란변수를 보정한 상태에서 각 연도별 혈압을 비교한 결과 수축기혈압은 9년째에서, 확장기 혈압은 2년째에서 대조군과 통계적으로 유의한 차이가 있었으며, 대조군의 평균 혈압이 전반적으로 증가되었다. 추적기간동안 혼란변수를 보정한 통합수축기 혈압은 대조군인 NLC-I과의 차이가 NLC-II는 1.7 mmHg, NLC-III는 2.0 mmHg, NLC-IV는 3.8 mmHg이었고, NLC-IV의 경우 그 차이가 통계학적으로 유의하였다. 확장기혈압의 경우에는 소음노출수준별로 유의한 차이가 없었다. 본 연구는 남성근로자에서 장기간의 소음노출은 혈압의 상승에 독립적인 영향이 있음을 시사하였다.

• 환경영향평가
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• 제20권4호
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• pp.443-453
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• 2011

The purpose of present study is to develop a noise map around Korean Train Express (KTX) line. It is also to evaluate the high speed railway noise influence in neighboring areas around KTX. In order to develop the noise map, noise source modeling and 3-D noise radiation simulation have been performed by means of SoundPLAN program. The result of the noise map has been verified in comparison with the measured noise level. Noise measurements have been performed at 15 locations around KTX line. At each locations, 6 microphones were located 1.5m and 3m above the ground at each of 25m, 50m and 75 m distances from a center of the KTX track. The noise map showed clearly the high speed railway noise influence in neighboring areas around KTX line. The present study has also showed the noise could be reduced by using noise barriers constructed at severely noise-exposed locations.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2006년도 춘계학술대회논문집
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• pp.742-749
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• 2006

For the purpose of finding if aircraft noise annoyance response is affected to variables when noise survey is performed, the questionnaire survey is conducted around the Gimpo International Airport in Seoul, Republic of Korea. This residential area is exposed to the aircraft noise and road traffic noise, simultaneously. Research areas are classified according to three different aircraft noise exposure levels expressed in WECPNL, under 75, between 75 and 80, and above 80 WECPNL, on aircraft noise map. The 7-step numerical magnitude with verbal category scales is used to measure the annoyance level. This surrey suggests that aircraft noise annoyance is not affected to an important extent by other noise sources (road traffic noise, community noise) and demographic variables (sex, age, education, occupation, dwelling type, length of residence). Aircraft noise annoyance would be related to complaint activity which is one of attitudinal variables.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2001년도 춘계학술대회논문집
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• pp.374-379
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• 2001

The satellite electronic equipment is exposed to high level random vibration environment during the launch of spacecraft. The random vibration can cause damage of electronic equipment. Thus very careful consideration on the launch environment, especially for high level random vibration, is required in the design stage of transponder equipments of communication satellite. For the structural integrity of the communication satellite transponder equipment under qualification level random vibration, Finite Element analysis was carried out using the commercial code, MSC/Nastran and ANSYS and stress levels are presented. In order to validate the femodel, modal test was also performed and compared with numerical results.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2007년도 추계학술대회논문집
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• pp.425-429
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• 2007

The noise problem has been a public interest for several years in Korea. Especially, the noises which were emitted from aircrafts on the airport and in the air have injurious effects on people over a vast range. Hence, there need vast data on the aircraft noise to evaluate the effect of various parameters. In present study, the works which consist of social surveys and noise measurements were conducted at points near the airport and the airbase. Total of 1,784 participants give effective responses in forty-five areas nearby the measurement points. Questionnaires asked the responses concerned with attitude, noise sensitivity, directive effects, secondary effects, annoyance and attempts to lower noise level exposed. From the field survey, the doseresponse relationship of community response to aircraft noise was established and there are different characteristics between civil and military aircraft. Though the study is still continuing on a few interest, one among some results is that %HA (%highly annoyed) of civil aircraft is higher than military's under the 70 WECPNL.

• International Journal of Railway
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• 제4권2호
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• pp.42-49
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• 2011

Today, rolling stock has become a fast and convenient mode of transportation and has witnessed increased demand. But the speed improvement has resulted in increased aerodynamic noise and therefore residential districts near the railroad tracks are exposed to ever increasing noise level. A study on methodologies for measuring and appraising rolling stock's environmental noise has therefore become an important area of endeavor. In the case of the environmental noise, there are no changes in tone so prediction can be made by reducing areas around the railway. The present study explores estimation of the noise around the railway using scale model, and the source of the noise has been investigated as well. The scale model of rolling stock will have to be able to measure high frequency noise and it is required to be generated in a short amount of time. Since popping a balloon or firing a gun fits this requirement the present study analyzed the characteristics of these two different noise sources. Measurement was made in a large vacant lot and the reflection due to the ground was also examined. The method proposed here can be used in the future for predicting the environmental noise of railway vehicles.