Building Equipment field is getting important recently which satisfies the requirement for pleasant living environment. But, the noise generated in the machinery room often violates the pleasant living environment of residents in complicated form of airborne noise and soild sound, its seriousness is increasing so that damage of noise can take large percentage of environmental complaints. So, soundproofing and insulation of sound which can minimize such noise and effective countermeasure in case of civil appeal are required, but research materials regarding building equipment are definitely insufficient domestically. In this respect, this study used Zwicker parameter which is applied by psychological and acoustic reactions according to sound quality, analyzed sound quality of 32 kinds of building equipment used in machine room, and analyzed correlation between dB(A) and PSIL which are items of Zwicker parameter and noise valuation based on that. As the results, if valuates altogether loudness and unbiased annoyance which have high correlation with other existing suggested valuating methods, it is considered that it can be utilized as basic data for more reasonable and accurate grasping characteristics of noise from building equipment and for building effective countermeasure in case of civil appeal.
본 연구에서는 Comfortone 기법 적용 전, 후 음압 수준(sound pressure level, SPL) 변화 정도와 영상의 화질 차이를 정량적으로 비교, 분석하여 소음 감소 기술의 유용성과 임상적으로 유의미한 기준을 제시하고자 하였다. 3.0 T 자기공명영상장비와 ACR 팬텀을 사용하여 Comfortone 적용 전, 후의 T1, T2 강조 영상과 DWI, FLAIR, 3D GE T1 영상을 획득한 후 ACR 정도 관리 가이드라인에 따라 기하학적 정확도, 고대조도 공간분해능, 절편 두께 정확도, 절편 위치 정확도, 영상 강도 균일성, 고스트 신호 백분율, 저대조도 분해능이 적합한지 비교, 평가하였으며 장비 내 표시되는 SPL을 통해 음압 수준의 감소 차이를 비교하였다. Comfortone 기법 적용 여부에 관계없이 DWI 영상은 왜곡이 심해 장비 정도 관리 가이드 라인에는 적합하지 않았으나 나머지 영상에서는 대부분 통계적으로 유의한 차이가 없었다(p>0.05). 몇 개의 항목에서 유의 한 차이가 있더라도(p<0.05) 영상 모두 ACR MRI 팬텀 장비 정도 관리 기준에는 적합했다. 음압 수준 변화는 T1에서 15%, T2와 FLAIR에서 40%, DWI과 3D GE에서 70%의 감소 차이를 보였다. 결론적으로 DWI을 제외하고는 모든 영상에서 검사 시간의 차이 없이 동일한 영상의 화질을 획득할 수 있었다. 따라서 Comfortone 기법을 적용하여 소음은 현저하게 감소시키면서 동시에 임상적으로도 기존의 영상과 동일한 화질의 영상을 제공할 수 있을 것이다.
Of the daily noises, construction noises cause serious conflicts between a construction firm and residents due to their high sound pressure level and shocking, repetitive sound. While South Korea regulates construction noises on the basis of legal criteria to minimize the damage from the noises, the regulation only involves a weighted sound level (dB(A)), which is loudness, like other types of noises. However, since construction noises are characterized by very diverse spectra and waveforms, it has been indicated that they cannot be reflected only by physical loudness: SPLdB(A). In addition, the need to reflect acoustic psychological characteristics and meanings of human beings in evaluating construction noises has recently been indicated. This study aimed to use six Zwicker parameters to determine the sound quality and acoustic psychological characteristics of construction noises and analyze the correlation between physical indexes of construction noises, as found in literature review, and the Zwicker parameters. Loudness of construction noises were closely correlated with SPLdB(A); shocking noises were perceived as ‘loud, sharp, and annoying’ sound. The Zwicker parameters were most strongly correlated with loudness, followed by unbiased annoyance and sharpness, among the evaluation indexes; as for correlation with construction noises, ‘normal noises’ were closely correlated with loudness, ‘shocking noises’ were closely correlated with loudness, unbiased annoyance, and sharpness, and ‘fluctuating noises’ were closely correlated with loudness. Therefore, if loudness, unbiased annoyance, and sharpness were taken into account in terms of the sound quality in evaluating construction noises, it is expected to be useful to make and revise criteria for regulating the noises.