Lamia Bouafif¹, Noureddine Ellouze²

Sound & Vibration, Vol.52, No.6, pp. 2-10, 2018, DOI:10.32604/sv.2018.02410

Abstract Sound indexing and segmentation of digital documents especially in the internet and digital libraries are very useful to simplify and to accelerate the multimedia document retrieval. We can imagine that we can extract multimedia files not only by keywords but also by speech semantic contents. The main difficulty of this operation is the parameterization and modelling of the sound track and the discrimination of the speech, music and noise segments. In this paper, we will present a Speech/Music/Noise indexing interface designed for audio discrimination in multimedia documents. The program uses a statistical method based on ANN and HMM classifiers. After… More >

Bin Chen^{1, *}, Shuyue Yu¹, Yan Gao²

Sound & Vibration, Vol.52, No.4, pp. 21-27, 2018, DOI:10.32604/sv.2018.03974

Abstract Investigations into active noise control (ANC) technique have been conducted with the aim of effective control of the low-frequency noise. In practice, however, the performance of currently available ANC systems degrades due to the effects of nonlinearity in the primary and secondary paths, primary noise and louder speaker. This paper proposes a hybrid control structure of nonlinear ANC system to control the non-stationary noise produced by the rotating machinery on the nonlinear primary path. A fast version of ensemble empirical mode decomposition is used to decompose the non-stationary primary noise into intrinsic mode functions, which are expanded using the second-order… More >

Matthew Muirhead, Iswandaru Widyatmoko

Sound & Vibration, Vol.52, No.3, pp. 2-5, 2018, DOI:10.32604/sv.2018.03846

Abstract Road traffic noise can have a significant impact on the quality of life for residents close to major road networks. One of the most effective measures for reducing the noise from road traffic, particularly on high-speed roads, is to ensure the use of a low noise road surface. Research on pavement construction and the measurement of its acoustic properties has shown that significant noise reductions can be achieved through the use of certain road surface types. However certain low noise road surfaces do not exhibit the desired durability associated with more traditional pavements, leading to costly and disruptive maintenance regimes.
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Shijie Jiang^*, Song Yang, Bohong Zhang, Bangchun Wen

Sound & Vibration, Vol.53, No.4, pp. 129-138, 2019, DOI:10.32604/sv.2019.04048

Abstract Aerodynamic noise is the dominant noise source of the high-speed train. It not only seriously affects the passenger comfort and people’s normal life along the railway line, but also may cause fatigue damage to the surrounding equipment and buildings. This manuscript carried out the simulation and experimental study on the external aerodynamic noise of high-speed train, in order to increase the understanding of the noise and hence to be better able to control it. The on-line tests were performed to verify that it is reasonable to simplify the high-speed train model. The turbulent air flow model was then developed, and… More >

Jidong Zhang^1,2,*, Wentao Sui², Jaspreet Dhupia³

Sound & Vibration, Vol.53, No.2, pp. 38-49, 2019, DOI:10.32604/sv.2019.04362

Abstract Occurrence of gear rattle in transmission systems can result in severe vibration and noise, which in applications such as automobiles is an important source of user discomfort. As a result , the reduction of the rattling noise has attracted lot of concerns. The rattling noise level is affected by several gearbox parameters, an understanding of which is essential to prevent the expensive design modifications at later stages of product development. To develop such understanding at the gearbox design stage, this paper analytically evaluates the gear parameters’ effect on the root mean square of the wheel gear acceleration under idling condition,… More >

Wen Zhao, Dongxing Mao^*, Zaixiu Jiang

Sound & Vibration, Vol.53, No.1, pp. 37-46, 2019, DOI:10.32604/sv.2019.04368

Abstract In order to analyze the effect of the background flow on the sound prediction of fine-scale turbulence noise, the sound spectra from static and flow environments are compared. It turns out that, the two methods can obtain similar predictions not only at 90 deg to the jet axis but also at mid- and high frequencies in other directions. The discrepancies of predictions from the two environments show that the effect of the jet flow on the sound propagation is related to low frequencies in the downstream and upstream directions. It is noted that there is an obvious advantage of computational… More >

Xueyun Ruan^1,2, Wei Huang¹, Linke Zhang³, Yan Gao^2,*

Sound & Vibration, Vol.53, No.1, pp. 2-13, 2019, DOI:10.32604/sv.2019.04562

Abstract Outdoor power transformers are one of the most pervasive noise sources in power transmission and distribution systems. Accurate prediction of outdoor noise propagation plays a dominant role for the evaluation and control of noise relevant to the transformer stations. In this paper surface vibration tests are carried out on a scale model of a single-phase transformer tank wall at different excitation frequencies. The phase and amplitude of test data are found to be randomly distributed when the excitation frequency exceeds the seventh mode frequency, which allows the single-phase power transformer to be simplified as incoherent point sources. An outdoor-coherent model… More >

N.Ishizuka¹, T.Okada², T.Ikeno², K.Shiomi², M.Okuma³

The International Conference on Computational & Experimental Engineering and Sciences, Vol.6, No.2, pp. 145-150, 2008, DOI:10.3970/icces.2008.006.145

Abstract The accurate modeling of structures is very important for any engineering analysis such as simulation and design optimization of mechanical systems for noise and vibration. It is desired that such a modeling process should not be time-consuming and that the created model must have structural dynamic properties corresponding with the actual ones. But in practice, it is often difficult or even impossible to satisfy the desire by using conventional theoretical methods such as the Finite Element Method (FEM) when we consider actual mechanical systems which consist of many substructures. In this paper, under the assumption that vibration tests can be… More >

Takéhiko Nakama¹

The International Conference on Computational & Experimental Engineering and Sciences, Vol.9, No.4, pp. 233-242, 2009, DOI:10.3970/icces.2009.009.233

Abstract Random noise perturbs objective functions in a variety of practical optimization problems, and genetic algorithms (GAs) have been widely proposed as an effective optimization tool for dealing with noisy objective functions. In this paper, we investigate GAs applied to objective functions that are perturbed by multiple sources of additive and multiplicative noise that each take on finitely many values. We reveal the convergence properties of GAs by constructing and analyzing a Markov chain that explicitly models the evolution of the algorithms in noisy environments. Our analysis shows that this Markov chain is indecomposable; it has only one positive recurrent communication… More >

Bin Dong^1,2,3, Changyong Jiang^1,3,*, Xiang Liu^1,3, Lixi Huang^1,3

The International Conference on Computational & Experimental Engineering and Sciences, Vol.21, No.2, pp. 26-26, 2019, DOI:10.32604/icces.2019.05017

Abstract How to reduce fan noise has always been a significant research topic in equipment ranging from small-scale devices, such as computer cooling fans and building ventilation fans, to large high bypass ratio turbo engines. In recent years, in order to produce higher pressure rise or larger flow rate with lower noise level in the fan stage, interest in the contra-rotating fan (CRF) configuration has been rekindled. The Vold-Kalman order tracking filter technique was employed to separate tonal and broadband noise components from CRF acoustic data to study the characteristics of the noise spectrum. Based on the spectrum peaks, noise reduction… More >