• KIEAE Journal
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• v.10 no.5
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• pp.109-114
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• 2010

There are many business in complex building, and recently noise claims have increased in those buildings. It is one of the most desirable methods reducing the noise level to establish the noise criteria considering the admittable noise level between the source and receiving room, which are to be derived from the subjective response in the real conditions. Because the degree of annoyance and loudness for the intruding noises in complex building could be changed with background noise level, it is suggested to be researched the relationship between the noise levels and subjective response. In this study, the subjective response for three different background levels in receiving business or rooms were investigated for the typical eight business noise source including aerobic music. The results can be summarized as follows. In conditions of low background noise level(40 dB(A)), there is a tendency of intentionally attention situation (listening) in a subjective test. The other hand in conditions of relatively high background noise level(50 dB(A)), there is a unconscious situation (heraing). As the degree of moderately heard or annoyed in SD rating scale means that the noise is easily recognized in neighboring shops, usually the limit of noise criteria were decided on this rating point, so it will be reasonable to be adopted the criteria rating scale as slight heard or annoyed degree (SD criteria 3).

• The Journal of the Korea institute of electronic communication sciences
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• v.14 no.1
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• pp.179-184
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• 2019

In this paper, we propose a design method of Active Noise Control (ANC) that reduces perceived level of the residual noise. A FELMS (Filtered-E Least Mean Squares) algorithm is used for the ANC system and the NC (noise criteria) is applied as an evaluation criterion of the residual noise. With this structure, we present the allowable spectral shape of the noise shaping filter that minimizes the NC index within the effective operating frequency band of the ANC, and showed that the filter satisfying in the criterion has a lower NC value than the psychoacoustic-based filter used in the previous studies.

• Journal of Environmental Science International
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• v.18 no.3
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• pp.263-269
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• 2009

The purpose of this study is to propose an appropriate criterium for proper sound insulation service preventing school classrooms from aircraft noise. The guideline of noise level for school facility by Korean school health law is less than Leq 55 which is less stringent than that of other countries. It has been reported that many students are annoyed and disturbed for their works when they are exposed to the noise level over Leq 55. It is desirable to modify this guideline of indoor noise level for school classroom. The noise level of classroom of which windows are opened was measured relatively high in case the school is located at the outside of the official area damaged by aircraft noise. In order to minimize the influence of aircraft noise on the school classrooms in the vicinity of domestic airport, it is necessary to improve the present criteria of WECPNL 75 for the establishment of the area damaged by aircraft noise from WECPNL 70.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.17 no.8
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• pp.726-735
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• 2007

Inside the factory buildings of aprecision industry (which produces semiconductors or TFT-LCD), thousands of vibration-sensitive precision equipments operate in the clean rooms. Various utility equipments that are installed around them for proper operation cause various sources of noise and of vibration to exist inside the clean rooms and thus deteriorate the noise and the vibration environment within. In this study, we check if the existing transient vibration phenomenon is caused by the vibrations that arise from operating the utility installed near these equipments; compare and evaluate the vibration criteria of precision equipments regarding the transient vibration phenomenon; and check the efficiency of these criteria.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.14 no.10
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• pp.968-974
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• 2004

Automakers have been forcing their suppliers to guarantee qualities of parts. Then, the suppliers have met the fundamental quality requirements such as dimensions and functions, but they could not sufficiently satisfy the automakers' noise requirements yet because automatic noise inspection systems were little successfully adopted In mass-production lines. This study tried to develop a system for automatically checking noise radiated from a rotating engine part and filtering parts emitting noise higher than criteria: the upper limits of a overall noise level or a noise spectrum. A commercial noise measurement system was used for measuring noise, and then the noise data was transmitted to a governing program through OLE(object, linking and embedding) functions. The governing program, belonging to a total noise inspection system managed the noise measurement and analysis. This system was successfully adapted for distinguishing bad parts according to the noise criteria.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.18 no.6
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• pp.663-673
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• 2008

The purpose of this study is to analyze the appropriate evaluation method for the water supply and drain noise of bathroom in apartment and to propose some fundamental idea on its regulation. For this reason, it was studied the acoustical characteristics of water supply and drain noise as modifying the water supply pressure for the washbasins and toilet stools and suggested the optimum evaluation method through psychoacoustic test. As a result of investigation of the levels by evaluating the adjectives and noise sources with 7-step criteria corresponding to each level of plumbing noises and analysis of the correlation between physical evaluation values by comparing the criteria, dB(A), N, and NC, with subject's response, determination coefficient($R^2$) was shown to be relatively fair or higher ranged from 0.65 to 0.92. It is shown that 'Harsh', 'Nervous', 'Unpleasant', 'Distasteful', and 'Repellent' as a second factor are to be appropriate to evaluate plumbing noise. Above these results could be used in basic data establishing KS(Korean Standard) for evaluation and rating procedure and measures reducing these noise.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2008.04a
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• pp.9-12
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• 2008

There are many place of business in complex building, and recently claims of noise have increased in those buildings. It is most desirable reducing the noise problems to establish the noise criteria considering the noise source and the receiving place of business, which are derived from the dose-response of noise and results of the actual condition. The degree of response to the transmission noise could be changed with background noise level in the receiving stores. In this research, the subjective evaluation for three different background level in receiving place of business or rooms were investigated from subjective tests. The eight business sound source including aerobic music were used for the test.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.13 no.8
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• pp.637-644
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• 2003

Airborne noise is one of the considerable environmental factors for navy ship personnel who should accomplish their tasks in restricted ship spaces against adverse health effect of noise. However, it is difficult to find studies on actual condition of airborne noise for navy ships. In this study, we measured airborne noise levels at 379 compartments of 33 Korean navy ships. Using the measured data, we presented mean values and their standard deviations of measured noise levels with factors of ship type, compartment category, and operation mode. Additionally, we evaluated the mean value and cumulative probability of airborne noise levels of compartments with those of the US navy ships. These results can be rationally used in making the proper airborne noise criteria of the navy ship for the future.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.16 no.2 s.107
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• pp.149-155
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• 2006

There are various types of noise around us such as road traffic noise, aircraft noise and floor impact sound, equipment noise, etc. Researches on the noise criteria and the evaluation method for the diffuser noise of HVAC are insufficient. dB(A) and NC values represented in ASHRAE guide book are applied as a noise criteria for diffuser noise, which have some problems like that the values between dB(A) and NC have deviation even if the sound is same one. Therefore, the evaluation method should be considered and proposed based on the subjective responses. From these reasons, this study aimed to analyze the evaluation factors for the diffuser noise of HVAC reflected on the subjective responses by surveying vocabularies and grouping them with factor analysis.

• KIEAE Journal
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• v.4 no.3
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• pp.37-44
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• 2004

In this study, foreign and domestic noise criteria on walls, floors, and water supply facilities were reviewed and the results are as follows : regulation can be divided two things, one is on thickness the other is sound insulation performance. Green Building regulation based on the law and this have sound classification systems. Since these regulations are not established in Korea. The noise regulation on water supply-drain facilities and domestic guideline on interior noise level is needed. Foreign regulations are stricter than those of ours. And those has sound classification system for the better acoustic condition of inhabitants'.