ORCID Profile
0000-0002-6261-8864
Current Organisations
RMIT University
,
University of Technology Sydney
Does something not look right? The information on this page has been harvested from data sources that may not be up to date. We continue to work with information providers to improve coverage and quality. To report an issue, use the Feedback Form.
Publisher: Elsevier BV
Date: 03-2020
Publisher: Elsevier BV
Date: 02-2019
Publisher: Acoustical Society of America (ASA)
Date: 12-2018
DOI: 10.1121/1.5082290
Abstract: This paper utilizes a rigid spherical microphone array to reduce wind noise. In the experiments conducted, a loudspeaker is used to reproduce the desired sound signal and an axial fan is employed to generate wind noise in an anechoic chamber. The sound signal and wind noise are measured separately with the spherical microphone array and analyzed in the spherical harmonic domain. The wind noise is found to be irregularly distributed in the spherical harmonic domain, distinct from the sound signal which is concentrated in the first few spherical harmonic modes. This difference is utilized to reduce wind noise without degrading the desired sound pressure level (SPL) by use of a low pass filter method in the spherical harmonic domain. Experimental results with both single-tonal and multi-tonal sound signals demonstrate that the proposed method can reduce wind noise by more than 10 dB in the frequency range below 500 Hz. The SPL of the desired sound signal can be extracted from wind noise with an error within 1.0 dB, even when the sound level is 8 dB lower than wind noise.
Publisher: Springer Science and Business Media LLC
Date: 15-10-2014
DOI: 10.1038/SREP06628
Publisher: SAGE Publications
Date: 10-01-2020
Abstract: Benzoxazine is a new kind of thermoset resin with excellent properties, but it suffers from high curing temperature and low char yield in the presence of catalyst without halogen. In(NO 3 ) 3 was herein used for the first time to efficiently catalyze the curing reaction of benzoxazine and to elevate the char yield at 800°C. The reaction of benzoxazine was catalyzed by In(NO 3 ) 3 after stirring at 35°C for 300 min, and the initial curing temperature decreased to 151°C. Polybenzoxazine/In(NO 3 ) 3 showed higher thermal stability and char yield at 800°C (increased by 7.5%) compared with those of polybenzoxazine. The possible pathway of coordination bonding between In 3+ and benzoxazine was proposed. In the cross-linking process, two different structures, that is, the N, O-acetal bridge structure and arylamine Mannich bridge structure formed at 35°C, both existed, which ultimately affected the thermal stability of the cured product.
Publisher: Elsevier BV
Date: 07-2021
Publisher: Acoustical Society of America (ASA)
Date: 2020
DOI: 10.1121/10.0000592
Abstract: Simultaneous measurements of wind velocity and pressure fluctuations were conducted in a wind tunnel to investigate the wind noise source inside compact spherical open celled porous windscreens. The existing outdoor wind noise models are found to be inadequate to predict the wind noise inside a wind tunnel. This paper proposes a model to predict the interior stagnation pressure, which agrees with the wind noise measured inside the windscreen within a bandwidth, where the exterior turbulence-turbulence interaction pressure overestimates the wind noise level. The limitations of the proposed model and other potential sources for wind noise inside porous windscreens are discussed.
Publisher: Acoustical Society of America (ASA)
Date: 11-2017
DOI: 10.1121/1.5012740
Abstract: Wind noise spectra caused by wind from fans in indoor environments have been found to be different from those measured in outdoor atmospheric conditions. Although many models have been developed to predict outdoor wind noise spectra under the assumption of large Reynolds number [Zhao, Cheng, Qiu, Burnett, and Liu (2016). J. Acoust. Soc. Am. 140, 4178–4182, and the references therein], they cannot be applied directly to the indoor situations because the Reynolds number of wind from fans in indoor environments is usually much smaller than that experienced in atmospheric turbulence. This paper proposes a pressure structure function model that combines the energy-containing and dissipation ranges so that the pressure spectrum for small Reynolds number turbulent flows can be calculated. The proposed pressure structure function model is validated with the experimental results in the literature, and then the obtained pressure spectrum is verified with the numerical simulation and experiment results. It is demonstrated that the pressure spectrum obtained from the proposed pressure structure function model can be utilized to estimate wind noise spectra caused by turbulent flows with small Reynolds numbers.
Publisher: MDPI AG
Date: 03-06-2021
DOI: 10.3390/S21113866
Abstract: Microphones have been extensively studied for many decades and their related theories are well-established. However, the physical presence of the sensor itself limits its practicality in many sound field control applications. Laser Doppler vibrometers (LDVs) are commonly used for the remote measurement of surface vibration that are related to the sound field without the introduction of any such physical intervention. This paper investigates the performance and challenges of using a piece of retro-reflective film directly as an acoustic membrane pick-up with an LDV to sense its vibration to form a remote acoustic sensing apparatus. Due to the special properties of the retro-reflective material, the LDV beam can be projected to the target over a wide range of incident angles. Thus, the location of the LDV relative to the pick-up is not severely restricted. This is favourable in many acoustic sensing and control applications. Theoretical analysis and systematic experiments were conducted on the membrane to characterise its performance. One design has been selected for sensing sound pressure level above 20 dB and within the 200 Hz to 4 kHz frequency range. Two ex le applications—remote speech signal sensing/recording and an active noise control headrest—are presented to demonstrate the benefits of such a remote acoustic sensing apparatus with the retro-reflective material. Particularly, a significant 22.4 dB noise reduction ranging from 300 Hz to 6 kHz has been achieved using the demonstrated active control system. These results demonstrate the potential for such a solution with several key advantages in many applications over traditional microphones, primarily due to its minimal invasiveness.
Publisher: Springer Science and Business Media LLC
Date: 27-09-2019
Publisher: Acoustical Society of America (ASA)
Date: 10-2022
DOI: 10.1121/10.0014958
Abstract: This letter introduces a database of Room Impulse Responses (RIRs) measured in seven different rooms for multizone sound field reproduction research in various acoustic environments. A circular array of 60 loudspeakers was installed in each room, with two microphone arrays placed sequentially in five different zones inside the loudspeaker array. A total of 260 400 RIRs were measured to establish the database. As a demonstration application of the database for multizone sound field reproduction, simulations were performed on the pressure matching and acoustic contrast control methods to investigate how a system optimized with the RIRs measured in one room would perform in other rooms.
Publisher: Elsevier BV
Date: 07-2019
Publisher: CAADRIA
Date: 2016
Publisher: Acoustical Society of America (ASA)
Date: 10-2017
DOI: 10.1121/1.5008860
Abstract: This paper investigates the wind noise reduction mechanism of porous microphone windscreens. The pressure fluctuations inside the porous windscreens with various viscous and inertial coefficients are studied with numerical simulations. The viscous and inertial coefficients represent the viscous forces resulting from the fluid–solid interaction along the surface of the pores and the inertial forces imposed on the fluid flow by the solid structure of the porous medium, respectively. Simulation results indicate that the wind noise reduction first increases and then decreases with both viscous and inertial coefficients after reaching a maximum. Experimental results conducted on five porous microphone windscreens with porosity from 20 to 60 pores per inch (PPI) show that the 40 PPI windscreen has the highest wind noise reduction performance, and this supports the simulation results. The existence of the optimal values for the viscous and inertial coefficients is explained qualitatively and it is shown that the design of the porous microphone windscreens should take into account both the turbulence suppression inside and the wake generation behind the windscreen to achieve optimal performance.
Publisher: RWTH Aachen University
Date: 2019
Publisher: Informa UK Limited
Date: 20-01-2020
Publisher: Elsevier BV
Date: 06-2015
Publisher: Acoustical Society of America (ASA)
Date: 02-2015
DOI: 10.1121/1.4906184
Abstract: This paper proposes a method of creating acoustic contrast control in an arc-shaped area using a linear loudspeaker array. The boundary of the arc-shaped area is treated as the envelope of the tangent lines that can be formed by manipulating the phase profile of the loudspeakers in the array. When compared with the existing acoustic contrast control method, the proposed method is able to generate sound field inside an arc-shaped area and achieve a trade-off between acoustic uniformity and acoustic contrast. The acoustic contrast created by the proposed method increases while the acoustic uniformity decreases with frequency.
Publisher: Elsevier BV
Date: 06-2020
Publisher: Acoustical Society of America (ASA)
Date: 09-2020
DOI: 10.1121/10.0001816
Abstract: Static pressure tubes are widely used to measure the static pressure in turbulent flows. Existing work focuses on the alteration of the static pressure tubes to the flow field. This paper investigates the effects of the geometric properties of a static pressure tube on the frequency response. A theoretical formulation is developed to describe the relationship between the sound pressure inside and outside the tube. The numerical simulation results show that the peaks in the frequency response move to lower frequencies when the tube diameter, tube length, and orifice depth increase and when the orifice diameter decreases. Experiments with a 3D-printed static pressure tube were conducted to verify the analytical results. The proposed model can be used to optimize the static pressure tube in the design stage or to correct the measurement results afterwards instead of cumbersome experimental calibration.
Publisher: Springer Science and Business Media LLC
Date: 13-09-2022
Publisher: SAGE Publications
Date: 26-04-2021
DOI: 10.1177/09540083211013091
Abstract: Polybenzoxazines are emerging as a class of high-performance thermoset polymers that can find their applications in various fields. However, its practical application is limited by its low toughness. The cyclic β-cyclodextrin and a newly synthesized derivative (β-cyclodextrin-MAH) were separately blended with benzoxazine to improve the toughness of polybenzoxazine. The results revealed that the maximum impact strength of the blend was 12.24 kJ·m −2 and 14.29 kJ·m −2 when 1 wt.% of β-Cyclodextrin and β-Cyclodextrin-MAH, respectively, were used. The strengths were 53% and 86% higher than that of pure polybenzoxazine. The curing reaction, possible chemical structures, and fractured surface were examined using differential scanning calorimetry, Fourier transform infrared spectroscopy, and scanning electron microscopy techniques to understand the mechanism of generation of toughness. The results revealed that the sea-island structure and the presence of hydrogen bonds between polybenzoxazine and β-cyclodextrin and β-cyclodextrin-MAH resulted in the generation of toughness. Furthermore, the curves generated during thermogravimetric analysis did not significantly change, revealing the good thermal properties of the system. The phase-separated structure and the hydrogen bonds present in the system can be exploited to prepare synergistically tough polybenzoxazine exhibiting excellent thermal properties. This can be a potential way of modifying the thermoset resins.
Publisher: IEEE
Date: 20-08-2022
Publisher: Elsevier BV
Date: 04-2021
Publisher: Institute of Noise Control Engineering (INCE)
Date: 08-2021
DOI: 10.3397/IN-2021-2150
Abstract: Mutlizone sound field reproduction aims to generate personal sound zones in a shared space with multiple loudspeakers. Conventionally, loudspeakers are placed to form a regular pattern such as circular, arc or linear array, which are empirical rather than optimal mainly for the convenience of physical placement. Recently, several algorithms have been proposed to select a fixed number of loudspeaker locations from a large set of candidate positions, such as the sparse regularization (i.e. Lasso and Elastic Net) methods, the Constrained Match Pursuit (CMP) method, the Gram-Schmidt Orthogonalization (GSO) method etc. Most of these methods were investigated for single-zone rather than mulit-zone sound field reproduction based on the pressure matching techniques. This paper compares the performance of the state-of-the-art techniques for loudspeaker position optimization in a multizone sound field reproduction system in terms of reproduction error, acoustic contrast and array effort. Simulation results demonstrate that the CMP-LS method shows the best performance in terms of lower MSE and higher AC while the Lasso method needs the lowest AE.
Publisher: Elsevier BV
Date: 10-2020
Publisher: Springer International Publishing
Date: 20-12-2021
Publisher: Acoustical Society of America (ASA)
Date: 05-2021
DOI: 10.1121/10.0005042
Abstract: Various array patterns, such as circular, linear, and arc-shaped arrays, have been used in multi-zone sound field reproduction, but most of them are based on empirical rather than judicious selection. This article proposes an iterative optimization method to select the loudspeaker positions from a large set of candidate locations. Both the number and locations of the loudspeakers can be designed with superior performance. Both single-frequency and broadband simulations based on the acoustic contrast control method are performed to validate the proposed scheme, and the performance of the optimized array is compared with that of an arc-shaped array and that of an array optimized with an existing method.
Publisher: Acoustical Society of America (ASA)
Date: 04-2022
DOI: 10.1121/10.0010309
Abstract: Multizone sound field reproduction aims to generate personal sound zones in a shared space with multiple loudspeakers. Traditional multizone sound field reproduction methods have focused on optimizing the source strengths given a preset array configuration. Recently, however, various methods have explored optimization of the loudspeaker locations. These can be categorized into sparse regularization and iterative methods with existing studies based on numerical simulations and mostly aiming at single-zone sound field reproduction. In this paper, unique experiments compare the state-of-the-art loudspeaker placement optimization methods by selecting a smaller number of loudspeakers from the candidates uniformly placed along a circle. An evolutionary array optimization scheme is proposed and shown to outperform the best existing methods in terms of mean square error in the bright zone and acoustic contrast between the bright and dark zones at frequencies below 1 kHz. The proposed evolutionary optimization scheme is simple, flexible, and can be extended to broadband optimization and other cost functions.
Publisher: Acoustical Society of America (ASA)
Date: 09-2015
DOI: 10.1121/1.4929933
Abstract: This paper proposes a different method for calculating a sound field diffracted by a rigid barrier based on the integral equation method, where a virtual boundary is assumed above the rigid barrier to ide the whole space into two subspaces. Based on the Kirchhoff-Helmholtz equation, the sound field in each subspace is determined with the source inside and the boundary conditions on the surface, and then the diffracted sound field is obtained by using the continuation conditions on the virtual boundary. Simulations are carried out to verify the feasibility of the proposed method. Compared to the MacDonald method and other existing methods, the proposed method is a rigorous solution for whole space and is also much easier to understand.
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 2023
Publisher: Elsevier BV
Date: 2021
Publisher: Research Square Platform LLC
Date: 15-02-2021
DOI: 10.21203/RS.3.RS-234787/V1
Abstract: Gas Metal Arc Welding (GMAW) is a welding process in which an electric arc is formed between a wire electrode and a metal work piece alongside a shielding gas to protect the arc from contaminants. There are several ways in which the molten electrode droplet can be transferred to the weld pool known as metal transfer modes. Identifying the metal transfer mode automatically is essential to monitor and control the welding process, especially in automated processes employed in modern Industry 4.0 manufacturing lines. However, limited research on this topic has been found in literature. This paper explores automatic classification of metal transfer modes in GMAW based on machine learning techniques with various signals from the welding process, including acoustics, current, voltage, and gas flow rate signals. Time and frequency domain features are first extracted from these signals and are used in a support vector machine classifier to detect the metal transfer modes. A feature selection algorithm is proposed to improve the prediction rate from 80% to 99% when all the four signals are utilized. When only the non-intrusive acoustic signal is used, the prediction rates with and without the proposed feature selection algorithm are approximately 96% and 81%, respectively. The high prediction rate demonstrates the feasibility and promising accuracy of the acoustic signal based classification method for future smart welding technology with real-time adaptive feedback control of the welding process.
Publisher: IEEE
Date: 23-05-2022
Publisher: Springer Science and Business Media LLC
Date: 04-06-2021
Publisher: Acoustical Society of America (ASA)
Date: 12-2022
DOI: 10.1121/10.0016443
Abstract: Wind noise is notorious for its detrimental impacts on audio devices. This letter evaluates the influence of wind noise on the active noise control performance of headphones in a wind tunnel, and the noise reduction is found to decrease with wind speeds. To improve the performance of noise control systems in windy environments, the filtered-x least mean squares algorithm is modified based on the total least squares technique, taking the characteristics of wind noise into account. Computer simulations with real-recorded data demonstrate that the proposed algorithm could improve the noise reduction by approximately 3 dB in windy conditions.
Publisher: Elsevier BV
Date: 03-2023
Publisher: Acoustical Society of America (ASA)
Date: 2018
DOI: 10.1121/1.5021335
Abstract: This paper explores the wind noise reduction mechanism of porous microphone windscreens by investigating the spatial correlation of wind noise. First, the spatial structure of the wind noise signal is studied by simulating the magnitude squared coherence of the pressure measured with two microphones at various separation distances, and it is found that the coherence of the two signals decreases with the separation distance and the wind noise is spatially correlated only within a certain distance less than the turbulence wavelength. Then, the wind noise reduction of the porous microphone windscreen is investigated, and the porous windscreen is found to be the most effective in attenuating wind noise in a certain frequency range, where the windscreen diameter is approximately 2 to 4 times the turbulence wavelengths (2 & D0/ξ & 4), regardless of the wind speed and windscreen diameter. The spatial coherence between the wind noise outside and inside a porous microphone windscreen is compared with that without the windscreen, and the coherence is found to decrease significantly when the windscreen diameter is approximately 2 to 4 times the turbulence wavelengths, corresponding to the most effective wind noise reduction frequency range of the windscreen. Experimental results with a fan are presented to support the simulations. It is concluded that the wind noise reduction mechanism of porous microphone windscreens is related to the spatial decorrelation effect on the wind noise signals provided by the porous material and structure.
Publisher: Acoustical Society of America (ASA)
Date: 12-2016
DOI: 10.1121/1.4968881
Abstract: Based on existing studies that provide the pressure spectra in turbulent flows from the asymptotic pressure structure function in the inertial range, this paper extends the pressure spectrum to the dissipation range by proposing a pressure structure function model that incorporates both the inertial and dissipation ranges. Existing experiment results were used to validate the proposed pressure structure function model first, and then the obtained pressure spectrum was compared with the simulation and measurement data in the literature and the wind-induced noise measured outdoors. All comparisons demonstrate that the pressure spectrum obtained from the proposed pressure structure function model can be used to estimate the pressure spectra in both the inertial and dissipation ranges in turbulent flows with a sufficiently large Reynolds number.
No related grants have been discovered for Sipei Zhao.