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

• The Journal of the Acoustical Society of Korea
• /
• v.34 no.2
• /
• pp.130-137
• /
• 2015

In this paper, we propose a new Modified Filtered-x Affine Projection Sign Algorithm(MFxAPSA) to improve the convergence speed of the conventional MFxAPSA which has been proposed for active control of impulsive noise. Under the impulsive noise environment, the adaptive algorithms based on the second order moment such as the Filtered-x Least Mean Square(FxLMS) show slow convergence speed or diverge because the noise source tends to have infinite variance. The MFxAPSA is the algorithm derived by applying the Affine Projection Sign Algorithm(APSA) to active noise control. The APSA has an advantage that it does not need the calculation for the inverse matrix, so it may be suitable for the active noise control that requires low computational burden. The proposed MFxAPSA also has APSA's advantage and furthermore, better performance than the conventional MFxAPSA. We carried out a performance comparison of the proposed MFxAPSA with the conventional MFxAPSA. It is shown that the proposed MFxAPSA has the faster convergence speed than the conventional MFxAPSA.

• Journal of KSNVE
• /
• v.8 no.6
• /
• pp.994-1003
• /
• 1998

ISO 산하에는 특정 기술분야마다 기술위원회(Technical Committee. TC)가 설치되고 규격의 제정과 개폐에 관한 실질적인 심의가 이루어진다 TC가 취급하는 범위가 넓을 때에는 분과위원회(Sub-Committee. SC)가 설치되게 된다.(중략)

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
• /
• 2006.05a
• /
• pp.712-721
• /
• 2006

• The Journal of the Acoustical Society of Korea
• /
• v.19 no.1
• /
• pp.73-77
• /
• 2000

It is necessary to express and evaluate annoyances, caused by noises, as a comparable quantity for establishing an efficient, economic and user-oriented noise control plan. In particular, cares should be taken for impact noises, since their dynamic properties are different from those of steady-state noises. A series of preliminary experiments were carried out to quantify the annoyances caused by floor impact noises. Results suggests that the characteristics of an impact source was more important factor than the properties of a floor structure for determining loudness and noisiness of subjects. Also, the heavy impact source was found to be felt louder and noisier by 5-6dB than the light impact source.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
• /
• 2006.11a
• /
• pp.371-371
• /
• 2006

The purpose of this study is to provide a fundamental data for efficient and economical reduction method and predict ion method of floor impact noise. In order to get the useful results, the measurement on the vibration transmission characteristics of standard test building with four rooms by using heavy and light-weighed impact source were carried out. In this measurement various conditions such as the change of test structure construction, the pick-up sensor location, the excitation posit ion, and the resilient material types were applied to get the vibration characteristics transmitted from excitation room to adjacent rooms.

• Transactions of the Korean Society for Noise and Vibration Engineering
• /
• v.15 no.5 s.98
• /
• pp.542-549
• /
• 2005

Impact sounds, such as those created by footsteps, the dropping of an object or the moving of furniture, can be a source of great annoyance In residential buildings. Running and jumping impact sound by child are one of the most irritating noises in an apartment buildings. It's necessary to know that the impact power characteristics of real impact source in an apartment buildings. This study aims to Investigate the impact power characteristics and impact power time of running and jumping by child. This study carried out investigation through the 159 children in school. The results of this study is that jumping impact power is greater than running impact power.

• Transactions of the Korean Society for Noise and Vibration Engineering
• /
• v.14 no.8
• /
• pp.661-667
• /
• 2004

The characteristics of noise and vibration by a heavy impact source was studied. The triggering method was used for increasing the reliability and stability to measure the level of sound pressure. sound intensity and vibration acceleration. A simple finite element model and a rigid body analysis method were suggested to calculate the natural frequencies of the multi-layer floor system. The results show that the resilient materials decrease the natural frequency of the reinforced concrete slab, make a resonance with dominant driving frequency in the low frequency region, and increase the vibration and noise level. A simple finite element model and rigid body models was suggested to calculate the natural frequencies of the floor systems.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
• /
• 2010.10a
• /
• pp.250-251
• /
• 2010

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
• /
• 2002.11a
• /
• pp.350.2-350
• /
• 2002

The purpose of this study was to present the possible use of a new standard impactor, the rubber ball (so-called, impact ball), and to assess its evaluation method as fur heavy-weight impact in multi-story residential buildings. Several experiments were carried out to investigate the effect of the impactor on noise propagation in reinforced concrete buildings. Then, the noise from the impact ball was psychoacoustically evaluated. (omitted)