Showing papers by "Yiu-Yin Lee published in 2014"
TL;DR: Wang et al. as mentioned in this paper identified the current usage, safety performance and negative impact of using chin straps on safety helmets in the Hong Kong construction industry and found that effectively using Chin straps can secure the helmets onto head and prevent it from rolling off.
20 citations
TL;DR: In this article, the authors investigated the correlation between the noise and vibration of a bridge movement joint without lane closure during the operation period and found that the two correlations are linear and similar to each other, even though the roadside noise is nonlinearly increasing against the control vehicle speed.
Abstract: This study addresses the research on the noise and vibration correlation of a bridge movement joint. The aim of this research is to assess the noise induced by the vibration of a bridge movement joint without lane closure during the operation period. There are two methods of developing the correlation between the tyre/joint noise and vibration: (i) Direct Sound and Vibration Measurement Method, (ii) Acoustic-Box-in-Vehicle Method. The first one is the measurements of the vibration change at a bridge movement joint and roadside noise change induced when a control vehicle is passing it (this one requires lane closure). The correlation between the vibration change and roadside noise change is plotted according the measurement data. The second one is the measurements of the structure-borne noise change in an acoustic box installed into the control vehicle and roadside noise change induced. Similarly, the correlation between the structure-borne noise change and roadside noise induced is plotted. It is found that the two correlations are linear and similar to each other, even though the roadside noise is nonlinearly increasing against the control vehicle speed.
5 citations
TL;DR: In this article, the absorption of a panel absorber under the effects of microperforation, air pumping, and linear and nonlinear vibrations is analyzed. And the theoretical result obtained from the proposed method shows reasonable agreement with that from a previous numerical integration method.
Abstract: This study includes the first work about the absorption of a panel absorber under the effects of microperforation, air pumping, and linear and nonlinear vibrations. In practice, thin perforated panel absorber is backed by a flexible wall to enhance the acoustic performance within the room. The panel is easily excited to vibrate nonlinearly and the wall can vibrate linearly. However, the assumptions of linear panel vibration and no wall vibration are adopted in many research works. The development of the absorption formula is based on the classical approach and the electroacoustic analogy, in which the impedances of microperforation, air pumping, and linear and nonlinear vibrations are in parallel and connected to that of the air cavity in series. Unlike those finite element, numerical integration, and multiscale solution methods and so forth, the analytic formula to calculate the absorption of a panel absorber does not require heavy computation effort and is suitable for engineering calculation purpose. The theoretical result obtained from the proposed method shows reasonable agreement with that from a previous numerical integration method. It can be concluded that the overall absorption bandwidth of a panel absorber with an appropriate configuration can be optimized and widened by making use of the positive effects of microperforation, air pumping, and panel vibration.
3 citations