• 한국소음진동공학회논문집
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• 제14권6호
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• pp.520-527
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• 2004

This study was carried out to investigate the present state of noise level including three general districts and two roadside areas at the Residential Area such as Sangmu, Pungam, Moonheung, and Ilgok Area. The noise level was measured quarterly. The results were shown that the noise level of day time was no great difference and that noise level of night time represented ranges between 44 to 48 dB(A). The noise level of day time was higher 4 to 7 dB(A) than night time. At the roadside areas, average noise level of day time was suitable to the requirements of environmental criteria. However. only one point of two points exceeded the noise level of environmental criteria. except Pungam Area. The noise level of night time in all areas was 58 dB(A), showing more 3 dB(A) than the environmental criteria (55 dB(A)). The difference of noise level between day time and night time was approximately 5 to 7 dB(A) in all Area. The noise level of day time was not dependent on all seasons, whereas that night time is dependent on season, especially showing lower noise level in winter. Showing the changes on the times in a day, it reached the highest at 16:00, mainly resulting in a lot of activities of people. The maximum noise level (Lmax) from 3 or 4 military aircraft showed almost the same. The noise level of aircraft in Sangmu Area was 71.5∼78.1 WECPNL.

• 한국주거학회논문집
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• 제19권1호
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• pp.1-8
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• 2008

This study is an attempt to understand the floor-specific characteristics of facade road traffic noise in apartment buildings. For this purpose, it sampled a total of seven roadside apartment building complexes: three with no soundproof bar barrier installed at roadside, one with a forest buffer zone, one with a sound-absorbing hill, and two with soundproof barriers. The measured noise level was highest on the 5th floor of apartment buildings with no soundproof barrier, and the upper stories from the 5th floor showed lower-noise measurements in order. For apartment buildings with soundproof barriers, however, the noise level was lower on the 10th floor than the 5th floor. Two apartment building groups--one with a sound-absorbing hill and the other with no soundproof barrier--showed similar measurement results in the floor-specific characteristics of facade road traffic noise. This suggests that such installations have little sound insulation effect. In the apartment building complex with a forest buffer zone around it, a slight sound insulation effect was measured on the lower floors of the buildings.

• 기본간호학회지
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• 제5권2호
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• pp.341-352
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• 1998

The purpose of this study was to provide a bases for comfort of patient through of measuring the noise level in emergency room and grasping the perception to noise of inpatient. Data on noise level through sound level meter in ER and patients' perception of the noise through a structured questionnaire and were collected from August 21 to September 5 in 1998. And collected data were analyzed with SAS statistics progeam, descriptive statistic, t-test and ANOVA. The result of examination is as follows : 1. Among a noise level of measured highest was 64.6dB(A) in 'rounding of medical teams', the lowest was 54.8dB(A) in 'traffic noise from outside'. 2. The mean score of noise perception was 0.93. Among a kind of noise reported by the subjects, that which ranked highest was 'conversation of patients' caregiver and visitors'(1.75). The ranked lowest was 'noise of airconditioner'(0.59). 3. The relationship between perception of noise and subjects' characteristics was not significient. Therefore, based on this result, ways require to decrease the noise level in emergency department.

• 한국도로학회논문집
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• 제14권5호
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• pp.201-206
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• 2012

PURPOSES: This study evaluated a measuring technique for tire-pavement interaction noise that uses a noble close proximity (NCPX) method as well as for noise level measured inside of a car (e.g., Inside Noise Level) in term of rumble strips constructed at a tall gate. METHODS: According to the measurements of NCPX and inside noise level (INL), 1/3 octave band frequency analysis and overall noise level calculation were conducted in order to evaluate noise levels of NCPX and INL, depending on types of rumble strips. RESULTS: The tested sections of general concrete pavement surface and two different types of rumble strips were evaluated, using 1/3 octave band frequency analysis and overall noise level. From the analyzed results, it can be concluded that rumble strips generate a relatively huge noise levels when compared to the concrete pavement surface. CONCLUSIONS: Noting that above 3 dBA different noise levels can let drivers know that they are getting close to toll gate; therefore, they should apply their brakes. Thus, the noise levels of rumble strips are required to be reduced, based on considering the neighbors living near toll gates.

• 성인간호학회지
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• 제13권2호
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• pp.209-222
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• 2001

The environment in the ICU leads to negative changes in a patient's usual sleep pattern and so contributes negatively to the patient's health condition as compared to patients in general wards. Therefore, it is thought that an important nursing intervention would be to identify the relation between noise and sleep patterns which play an important role in illness recovery. The purpose of the present study was to explore the relationship between noise in the ICU and the sleep pattern of patients admitted to the ICU. A descriptive correlation design was used to examine the relationship. Thirty-four subjects were recruited from a Medical ICU (MICU), Surgical ICU (SICU) and Coronary Care Unit (CCU) at a large university hospital in Suwon. Data were collected from September 28 to October 31 in 1999. In the present study, noise was categorized into noise level and patients' perception of noise. The objective noise level was measured using the A-Weighted Sound Level Meter. The patients' preception of noise was measured using a self-reported questionnaire developed by the researcher. Sleep patterns in this study includes both quantity and quality of sleep. These were measured using open ended questionnaires and the 'Korean Sleep Scale A' developed by Oh, Song, Kim(1998). The data was analyzed using the SPSS-WIN to test the research question, Pearson product moment correlation coefficient was run. Ancillary analysis were conducted with demographic variables to determine their relation to the main study variables. For the ancillary analysis, t-test and one-way ANOVAs were performed. The results of the present study are summerized as follows : 1. The total mean of objective noise level (10pm-6am) was 56.2dB. The means for night time noise level in individual ICUs for the SICU, MICU and CCU, were 58.7dB, 58.6dB and 48.3dB, respectively. The total mean for patients' noise perception was 42.8 out of a maximum possible score of 76. For item means of noise perception, the one ranked highest was "conversations between doctors and nurses" (3.2). The one ranked lowest was "noise from the radio" (1.2). Regarding the degree of perception for each type of noise source, the one ranked highest was "equipment noise" (2.6), the second was "conversation between medical staff" (2.4), the third was "conversation between patients, caregivers and visitors" (2.3), and the one ranked lowest was "environment noise" (1.8). 2. Looking at quantity of sleep of ICU patients, the mean nocturnal sleep time was found to be 4.9 hours. The total mean of sleep quality for ICU patients was 21.0 out of a maximum possible score of 40. 3. The relationship between perception of noise and quantity of sleep was statistically significant(r= - .41, p<.05). The relationship between perception of noise and quality of sleep was also statistically significant(r= - .47, p<.01). The results of the study indicate that personal perception of noise is related to sleep patterns. Therefore, it is suggested that nursing interventions be developed to reduce the degree of personal perception of noise and, thus, decrease sleep pattern disturbances in patients in the ICU.

• 한국음향학회지
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• 제38권4호
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• pp.378-386
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• 2019

항해하는 선박으로부터 방사되는 선박소음과 달리 바람소음은 바람과 해수면의 상호작용으로 생성된 쇄파에 의해 발생한다. 본 논문에서는 바람의 소음원을 쇄파로 인해 발생되는 기포운으로 설정하여 바람소음준위를 모델링하였다. 모델링에서 바람소음의 음원준위는 동해 연안에서 운영되는 기상부이로부터 측정된 풍속 자료를 이용하여 계산하였다. 풍속을 측정함과 동시에 기상부이의 주변에 계류된 자가기록식 수중청음기를 이용하여 소음준위를 연속적으로 측정하였다. 측정된 수중소음에서 선박소음을 제거한 소음준위와 풍속에 따라 모델링된 바람소음준위를 저주파대역에서 비교하였다. 모델링된 바람소음준위와 측정된 소음준위의 전반적인 경향이 서로 유사하였다. 이에 따라 바람에 의해 발생된 소음원인 기포운의 음원준위 및 분포 수심을 고려하여 천해역에서 바람소음준위를 모델링하는 것이 가능함을 확인하였다.

• 한국소음진동공학회논문집
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• 제26권1호
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• pp.20-26
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• 2016

This study investigated noise characteristics of air cleaners and humidifiers in terms of frequency domains and measurement directions. Noise levels of 31 air cleaners and 36 humidifiers were measured in an anechoic chamber according to the related group standards. As for air cleaners, 5 receiving points of 1 m off from front, rear, left, right and top surfaces of the product were considered. In case of humidifiers, 4 receiving points without the rear position were considered in the same manner as air cleaners. In each case, A-weighted equivalent continuous sound level was measured three times for 1 min. As a results, most of the measured air cleaners and humidifiers showed the highest noise levels at top directions due to the air ventilating location. In case of air cleaners, averaged noise levels of top and rear positions were 49.9 and 48.2 dB(A), respectively, whereas averaged noise level of other positions was all 45.2 dB(A). In case of humidifiers, averaged noise level of top position was 44.1 dB(A) whereas averaged noise levels of other positions were 38.7 to 39.1 dB(A). In addition, high frequency content of 1 kHz and 3.15 kHz to 4 kHz for air cleaners and middle frequency content of 500 Hz to 1.6 kHz for humidifiers showed significant contribution to determination of overall noise levels with correlation coefficient of 0.9 and above.

• 화약ㆍ발파
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• 제18권2호
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• pp.14-22
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• 2000

발파소음을 계측하여 예측방법의 타당성을 검토하였고, 환경규제 기준으로의 변환방식을 규명하였다. 환산거리에 따른 발파소음의 예측은 환산거리와 음압레벨의 상관성이 더 좋았으나, 상관계수가 낮아서 환산거리 설계 의한 발파소음의 조절은 어려움이 있었다. 발파시 동시에 측정된 음압레벨과 소음레벨의 상관식에 의한 변환과, 음압레벨의 우세주파수에 해당하는 청감보정회로의 보정치만큼 간이 보정하여 변환하는 방법과, 퓨리에 변환을 하여 청감보정한 후 소음레벨을 구하는 방법을 시도하였다. 세 가지 방법 모두 변환하는 데에는 많은 오차가 발생하였으나 우세주파수, FFT를 이용한 변환보다는 발파시 동시에 측정된 음압레벨과 소음레벨의 상관식에 의한 변환 방법이 가장 실용적인 방법이었다.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2003년도 추계학술대회논문집
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• pp.533-536
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• 2003

The Low frequency(1-200 Hz) noise levels radiated by road traffic were investigated. The results showed that the peak pass-by noise of truck with speed of 60km/h was about 75㏈. For the infra-sound frequency range, the noise was about 65㏈ and it was less value than expected. But the noise level will be increase as increasing the speed. The pass-by noise for train was also measured for comparison. The peak train noise was about 95㏈ and it will be enough noise level for a human body to give nuisance.

• 수산해양기술연구
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• 제16권2호
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• pp.69-76
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• 1980

This paper describes the measurement of the underwater noises produced by the engine vibration around the engine room of stern trawler MIS Sae-Ba-Da(2275GT, 3,600 PS) and pole kner M/S Kwan-Ak-San (243 GT, 1000 PS) while the ship is stopping. The underwater noise pressure level was measured with the underwater level meter of which measuring range is 100 to 200 dB(re bLPa). A and B denotes the maximum pressure level measured at right beneath the bottom of the engine room, while the main engine of the Sae-Ba-Da revoluted at 750 and 500 rpm, respectively. C denotes that of the main engine of the Kwan-Ak-San revoluted at 350 rpm, and D that of the generator of the Sae-Ba-Da revoluted at 720 rpm. Thus A, B, C and D were set for the standard sound source for the experiment. The results obtained are as follows: 1. The noise Pressure level at A, B, C and D were 170.5,165,153 and 158dB, respectively. 2. When the check points distanted vertically 1, 10, 20, 30, 40, 50m from the sound source, the underwater noise presure levels were 170.5, 155, 148, 144 and 138 dB and the directional angle was 116\ulcorner in case of A. 3. The sound level attenuated at the rate of 20dB per 10" meters of the horizontal distance from the sound sources. 4. The frequency distribution of the noise was 100Hz to 10KHz and predominant frequency was 700 to 800Hzminant frequency was 700 to 800Hz