• 한국조경학회지
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• 제26권3호
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• pp.19-33
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• 1998

The primary objective of this research was to develop optimal models for masking the road traffic noise with the sound of a waterfall at urban small green spaces. Noise levels were measured at 8 roadside green spaces in SEOUL and questionnaires were randomly distributed to 40 users for evaluating the noise at each site at the same time. College students participated in the experiment for the development of masking models and the developed models were tested by users at 2 green spaces. The major results are as follows ; 1. Traffic noises ranged from 65dBto 70 dB. Users' satisfaction with the noise became considerably low on the basis of 60 dB and it was highly related to noise level. 2. Noise was a main factor to depreciate the amenity of green spaces where its level was more than 60 dB and so it neds to be excluded or reduced the traffic noise at the process of design. 3. Masking effects kept constant independent of the spatial location of masker on condition that masker levels were equal. It was effective when masker was 5-10dB greater than noise level which was masked. 4. As noise level went up, satisfaction ratings about the masked noise became low but masking effects increased in proportion to its level. 5. It was proved that the models were valid through the field experiment.

• 산업경영시스템학회지
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• 제24권65호
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• pp.65-73
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• 2001

In this study, psychophysiological stress was quantitatively evaluated at various car interior noise levels by using Electroencephalogram(EEG). An experiment was performed to investigate the most comfortable range of noise level during simulated driving condition. Twelve healthy volunteers participated in the experiment. They were asked to operate the driving simulator while six levels of interior noise were given, such as 45dB(A), 50dB(A), 55dB(A), 60dB(A), 70dB(A), 80dB(A), and maximal subjective noise level. EEG signals were recorded for 60 seconds in each noise level. The power spectral analysis was performed to analyze EEG signal. At the same time, psychological stress was also measured subjectively by using a magnitude estimation method. The results showed that subjective stress and EEG spectrum indicated a statistically significant difference between noise levels. In particular, high level noise produced an increase in beta power at temporal(T3, T4) areas. It was also found that beta activity was highly correlated with subjective perception of discomfort, and subjects responded to car interior noise as arousing or negative stimuli. Moreover, beta power remained stable above 70dB(A), whereas subjective discomfort continued to increase even above 70dB(A) We concluded that brain waves could provide psychophysiological information of drivers emotional reaction to car interior noise. Thus, EEG parameters could be a new measure to determine optimal noise level in ergonomic workplace design after further verification in various experimental conditions.

• 한국소음진동공학회논문집
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• 제25권4호
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• pp.275-283
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• 2015

The aim of this study is to estimate the noise exposure of roadside apartment complex according to the characteristics of apartment complex. The facade noise level of residential buildings and the ground noise level inside apartment complexes were predicted and analyzed using noise mapping based on a computerized noise model. In addition, the correlation analysis between these noise levels and the characteristics of apartment complex such as traffic volume, building coverage, the number of adjacent roads, etc. was done in a total of 21 apartment complexes. The results showed that building facade noise level and ground noise level were positively correlated with traffic volume (correlation coefficient, r=0.616~0.623) and the number of adjacent roads (r=0.340~0.496). On the other hand, they were negatively correlated with building coverage (r=-0.413~-0.477) and complex area per the number of roads (r=-0.478~-0.615).

• 한국간호교육학회지
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• 제3권2호
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• pp.150-162
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• 1997

The purpose of this study is to examine hospital noise level and discomfort due to noise. The subjects were 156 patients from University hospital in Taegu. The data was collected from April 10 to May 14, 1997. The collected data were analyzed by SPSS program using percentage, paired t-test, ANOVA, and Pearson Correlation Coefficient. The results were as follows ; The mean score of noise level was 1.62. There was no statistically significant difference in noise level between day and night. Patients perceived higher noise in the categories of conversation of visitors, conversation of care providers, noise of air conditioners, and the conversation of nearby patients than others during the day. Patients perceived higher noise in the categories of noise of air conditioners, conversation of visitors, conversation of care providers, and telephone ringing than others during the night. There were no statistically significant differences in noise level among the 4 wards during the day or night. Discomfort was due to the forementioned noise, categories of high scores were sleep disturbed, irritated, not so bad or not noisy, and noisy. To avoid noise, the subjects coped by putting on a quilt, going out, sleeping, opening or closing the window or door, and plugging ears. These results indicated that hospital noise have a negative influence on patients' health. So noise levels should be reduced in hospitals.

• 한국환경과학회지
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• 제16권12호
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• pp.1393-1399
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• 2007

This research helps you understand the road traffic noise levels by using a noise map. We have observed the change of the road traffic noise levels around $07:00{\sim}08:30\;and\;22:00{\sim}23:00$ using the noise map in the city. The road traffic noise level is very high both at noon and at night around a beltway and an interchange that is linked with a highway. It seems that the main route of so many vehicles, which are at neighboring cities such as N city and D and H districts and which avoid traffic jams in the city, is the beltway and interchange. The road traffic noise level of a nearby express bus terminal, railroad station, and airport is more than 75 dB at noon and 65 dB at night. The road traffic noise level of G city at night is observed to be more than 55 dB. The noise levels of a residence area and a university are higher than a road with high noise levels when the commuters drive to work. The end of the day exceeds 11 o'clock because of a culture level of development that arouses spare time, eating out, adults' drinking culture, nightlife of the youth, etc. Therefore, the road traffic noise level is high during late night hours, and it exceeds regulatory guidelines(55 dB(A)). It also damages the residence area that is located near the road.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2004년도 추계학술대회 논문집
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• pp.729-732
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• 2004

An experimental and numerical approach has been carried out for to see the noise characteristics of a circular diamond saw. The noise level measurement result for the several kinds of shanks shows us that the noise level reduction in high frequency range could be an effective way to control the noise problem. Sandwich type shank whose center part is laminated with a low Young‘s modulus material greatly reduces the noise level. The noise level for the shank where several curve shaped slits are provided in the circumferential direction is reduced considerably too. The response spectrum analysis by the FEM shows us to be an alternative for predicting the noise characteristics of the shank.

• 한국소음진동공학회논문집
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• 제15권6호
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• pp.718-723
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• 2005

The purpose of this study is to present a fundamental data for evaluating aircraft noise of building site development. By the field experiments and the predicted equal noise level contours using the INM program, actual condition in the building site development arranged district was investigated. In order to get the results, Analysis of factors effected on noise level, sound level on the rate of increase to aircraft demand and difference on the aircraft noise levels according to floor level in apartment house was carried out. As a result the influence of the take-off and landing direction were appeared greatly. The influences of the height at receiving point, movement number of aircraft and increase to aircraft demand were appeared small And the influence of 1 day average WECPNL must be considered.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2014년도 추계학술대회 논문집
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• pp.885-887
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• 2014

Outdoor spaces in an apartment complex have been enlarged by the increased underground car parking. It has become accepted as important place for acoustic comfort of resident. This paper attempts to determine the noise exposure to the outdoor area in 21 apartment complexes built within 5 years. The results showed that the average noise level of outdoor area ranged from 37.6dB(A) to 67.2dB(A). And the percentage of areas below the noise level of 55dB(A) range 0.1% to 95.0%. The analysis on correlations shows that the traffic volume and building coverage have significant effects on noise level.

• International Journal of Naval Architecture and Ocean Engineering
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• 제4권4호
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• pp.374-385
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• 2012

The indoor noise of a ship is usually determined using the A-weighted sound pressure level. However, in order to better understand this phenomenon, evaluation parameters that more accurately reflect the human sense of hearing are required. To find the level of the satisfaction index of the noise inside a naval vessel such as "Loudness" and "Annoyance", psycho-acoustic evaluation of various sound recordings from the naval vessel was performed in a laboratory. The objective of this paper is to develop a single index of "Loudness" and "Annoyance" for noise inside a naval vessel according to a psycho-acoustic evaluation by using psychological responses such as Noise Rating (NR), Noise Criterion (NC), Room Criterion (RC), Preferred Speech Interference Level (PSIL) and loudness level. Additionally, in order to determine a single index of satisfaction for noise such as "Loudness" and "Annoyance", with respect to a human's sense of hearing, a back-propagation neural network is applied.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2004년도 추계학술대회논문집
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• pp.1040-1043
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• 2004

The purpose of this study is to present a fundamental data for evaluating aircraft noise of building site development. By the field experiments and an predicted equal noise level contour using the INM program, actual condition in the building site development arranged district was investigated. In order to get the results, Analysis of factors effected on noise level, sound level on the rate of increase to aircraft demand and difference on the aircraft noise levels according to floor level in apartment house was carried out.