• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.24 no.6
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• pp.483-492
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• 2014

Uncomfortable feelings of occupants by indoor floor impact noise in a residential building are not accurately represented by the floor impact noise from a standard impact source. It is due to the characteristics of standard impact sources, which are different from the impact forces produced by occupants. It varies significantly by impact source, and it is not easy to be replicated for testing. As a result, the indoor floor impact noise under different acoustic conditions cannot be directly compared. Using frequency response function(FRF), which represents the input-output relationships of a dynamic system, it is possible to examine the characteristics of the system. Especially, FRF can predict the response of a linear dynamic system subjected to various excitation. To determine the relationship between impact force and the corresponding response of dynamic system in residential building, the acceleration response of a concrete slab and the floor impact noise in the living room, produced by bang-machine and rubber-ball excitation, were measured. The test results are compared to the estimates based on FRF and impact force spectrum.

• Proceedings of the KSR Conference
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• 2005.05a
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• pp.522-529
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• 2005

The commercial service of KTX from April 1st 2004 has realized that whole country has shrunk into half-day life zone and it opened the times of speed. However, some technical problems unexpected before service have been raised and, among them, the noise generation at train passing was claimed by the residents living nearby the track and it is often publicized by the broadcastings and newspapers. In case where the residential area is close to the track, the installation of noise barrier at trackside is the general measures for noise reduction on bridge section and earthwork section. In case of KTX project, such measures were actually taken without any exception; however, the noise level is still high. In this study, analysis for the reason of higher noise level in spite of which the noise barriers are being installed was carried out, the sample of insulation material effective for noise barrier was manufactured and the performance of the insulation material was evaluated to verify its effectiveness

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2002.05a
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• pp.592-597
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• 2002

The purpose of this study was to analyze the characteristics of a new heavy weight impactor, the Rubber Ball. Until now Bang-machine has been used to measure the heavy impact noise in accordance with JIS A 1418-1. However, various kinds of examination methods have been needed to make an objective observation of insulation capacity for floor impact noises. Two types of experiments were undertaken. First, the experiment about noise was carried out about an apartment building in actual living condition. Then. vibration noises from the impactors were analyzed. The results of this study were as follows : the result of experiment carried out with bonded area of bail was closer to practical experiment than that of non bonded area. In addition, the result about bonded area of ball was more similar to the result which is claimed by H. Tachibana than that about non bonded area. Moreover, it was found that Rubber Ball has more similar vibration characteristics to the real impact noise source than Bang-machine.

• Journal of Service Research and Studies
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• v.2 no.2
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• pp.99-113
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• 2012

Government and many universities have been trying to get the more international students. Foreign students in university are increasing remarkably in Korea. So these authorities have to consider their service competency for new foreign student's living satisfaction. In this paper, we described about the living satisfaction degree on the university dormitory's service in Korea. After reviewing and summarizing the related literatures, our hypotheses are established which the satisfaction be affected by some service factors such as facility, foods, and noise factors in university dormitory's environments. The 99 Chinese students living in G-university dormitory responded to our study. Empirical analysis was performed among a university in Sungnam city named as G-university by using questionnaires sheets. Analysis results are show that satisfaction degree on the university dormitory's service is affected significantly by facility and foods service factors respectively. However noise factor was not the significant variable.

• 한국신재생에너지학회:학술대회논문집
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• 2010.06a
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• pp.180.1-180.1
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• 2010

Wind turbine noise is generally lower than that from other environmental noise sources such as road and railway noise. Nevertheless, some residents living more than 1km away from wind turbines have claimed that they suffer sleep disturbance due to wind turbine noise. Several researchers have maintained that residents near a wind farm may perceive large amplitude modulation of wind turbine noise at night, and this amplitude modulation is the main cause of the noise annoyance. However, to date only few studies exist on the prediction of the amplitude modulation of wind turbine noise. Thus, this study predicts amplitude modulated noise generated from a generic 2.5MW wind turbine. Semi-empirical noise models are employed to predict the modulation depth and the overall sound pressure level of the wind turbine noise. The result shows that the amplitude modulation is observed regardless of atmospheric stability, but the modulation depth in a stable atmosphere is 1~3dB higher than that in an unstable atmosphere near the plane of rotation where the blades move downward. Moreover, using the result of the noise prediction, this study estimates the maximum perceptible distance of the wind turbine noise cause by amplitude modulation. The result indicates that the wind turbine noise can be perceived at a distance of up to 1600m in the range of about 30~60 degree from the on axis in a extremely low background noise environment.

• The Journal of the Acoustical Society of Korea
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• v.25 no.3
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• pp.129-136
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• 2006

For the environmental noise assessments. A weighted equivalent noise level (LeqA) is used to measure the time varying environmental noise. However, it is not appropriately reflect various environmental noise features and human emotions. The human perception of the noise is affected largely by the psychoacoustic characteristics of noise as well as the sound pressure level In this study, the effective factors of noise qualify are analyzed using the subjective assessment and statistical analysis of environmental noise, such as road traffic noise. construction site noise, noise in daily living. and other. The analysis methodology is composed to three steps as follows : firstly, the values of the sound qualify metrics of various noise sources were analyzed. And to classify the noise sources, we conducted a cluster analysis using sound quality metrics. Secondly, subjective jury testing was carried out using the methods of paired comparisons and semantic differential. Finally, the correlation between the subjective parameters and the noise quality metrics were analyzed. As a result. the human perception characteristics of the various environmental noise are described in some physical parameters of the noise qualify metrics.

• Journal of the Korean Home Economics Association
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• v.42 no.5
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• pp.93-106
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• 2004

The purpose of this study is to make clear the indoor environmental efficiency and spatial function of the front balcony in apartments using responses from residents'. An interview survey carried out during the 14/sup th/∼24/sup th/ of January 2003, and a questionnaire survey was given during the 17/sup th/∼29/sup th/of January. Interviewees consisted of 31 residents living in renovated apartments, which had the front balcony added onto the living room. The respondents of the questionnaire survey consisted of 37 residents living in ordinary apartments with an existing front balcony. The residents living in ordinary apartments show relatively positive responses on the indoor thermal environment during winter, glare by daylight, and outdoor noise. The average heating charges of the renovated apartments came out to be more expensive than the ordinary apartments. In most renovated apartments, the living area converted from front balcony was used as the same functions ('space for drying the laundry', 'storage space', or 'space for cultivating of flower pots') of ordinary front balcony. From the results of this study, it is undesirable to renovate the front balcony as an addition to the livingroom.

• International Journal of Internet, Broadcasting and Communication
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• v.9 no.2
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• pp.42-47
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• 2017

In these days, the size of urban is growing and the function of city becomes complicated. And also, in city, people lives a lot. The life of urban is getting closer and linked with neighboring people in many parts. Especially, when peoples are exposing during using public transportation, even though does not be known, in they were living. Seoul is the most crowded place in Korea. In Seoul,The village buses have been serviced to the narrow streets. And people who use this bus, wants to seek the comfort of the ride, air quality and noise during in vehicle. In this paper, we determine the degree of annoyance with the noise inside the town bus in dB scale. And, such a situation was confirmed annoyance see their effect. The Interior noise did not see a big difference in the new car and the old car. Annoyance but also according to the skill of the bus driver remains the difference was confirmed.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2005.05a
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• pp.96-99
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• 2005

Noise and vibration generated by heavy-weight floor impact in apartment buildings were studied. The resonance frequency increased in the floor structures where damping materials were used in the living room and the bedroom. Both the acceleration wavelength and the acceleration level decreased. The results showed that the resonance frequency increased and vibration acceleration level decreased when the damping materials were used. Heavy-weight impact sound levels of the structure decreased substantially below 80Hz.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2007.05a
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• pp.956-959
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• 2007

The extension of a road system result from construction of the builling near the noise source as the roads, railroads. Many people who have a living space near the road are damaged by the noise generated the road system. Therefore, the damage will be reduced by the appropriate measure like putting some distance between receiver and source. The windows are weak among the building materials. But mainly we uses the windows as building exterior materials. So the sound insulation of the balcony windows was measured and compared.