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Numerical Study on Reduction in Aerodynamic Drag and Noise of High-Speed Pantograph 被引量:1
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作者 Deng Qin Xing Du +1 位作者 Tian Li Jiye Zhang 《Computer Modeling in Engineering & Sciences》 SCIE EI 2024年第5期2155-2173,共19页
Reducing the aerodynamic drag and noise levels of high-speed pantographs is important for promoting environmentally friendly,energy efficient and rapid advances in train technology.Using computational fluid dynamics t... Reducing the aerodynamic drag and noise levels of high-speed pantographs is important for promoting environmentally friendly,energy efficient and rapid advances in train technology.Using computational fluid dynamics theory and the K-FWH acoustic equation,a numerical simulation is conducted to investigate the aerodynamic characteristics of high-speed pantographs.A component optimization method is proposed as a possible solution to the problemof aerodynamic drag and noise in high-speed pantographs.The results of the study indicate that the panhead,base and insulator are the main contributors to aerodynamic drag and noise in high-speed pantographs.Therefore,a gradual optimization process is implemented to improve the most significant components that cause aerodynamic drag and noise.By optimizing the cross-sectional shape of the strips and insulators,the drag and noise caused by airflow separation and vortex shedding can be reduced.The aerodynamic drag of insulator with circular cross section and strips with rectangular cross section is the largest.Ellipsifying insulators and optimizing the chamfer angle and height of the windward surface of the strips can improve the aerodynamic performance of the pantograph.In addition,the streamlined fairing attached to the base can eliminate the complex flow and shield the radiated noise.In contrast to the original pantograph design,the improved pantograph shows a 21.1%reduction in aerodynamic drag and a 1.65 dBA reduction in aerodynamic noise. 展开更多
关键词 High-speed pantograph aerodynamic drag aerodynamic noise reduction optimizing
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Ordered successive noise projection cancellation algorithm for dual lattice-reduction-aided MIMO detection 被引量:2
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作者 刘金铸 邢松 沈连丰 《Journal of Southeast University(English Edition)》 EI CAS 2013年第3期229-234,共6页
A novel nonlinear multi-input multi-output MIMO detection algorithm is proposed which is referred to as an ordered successive noise projection cancellation OSNPC algorithm. It is capable of improving the computation p... A novel nonlinear multi-input multi-output MIMO detection algorithm is proposed which is referred to as an ordered successive noise projection cancellation OSNPC algorithm. It is capable of improving the computation performance of the MIMO detector with the conventional ordered successive interference cancellation OSIC algorithm. In contrast to the OSIC in which the known interferences in the input signal vector are successively cancelled the OSNPC successively cancels the known noise projections from the decision statistic vector. Analysis indicates that the OSNPC is equivalent to the OSIC in error performance but it has significantly less complexity in computation.Furthermore when the OSNPC is applied to the MIMO detection with the preprocessing of dual lattice reduction DLR the computational complexity of the proposed OSNPC-based DLR-aided detector is further reduced due to the avoidance of the inverse of the reduced basis of the dual lattice in computation compared to that of the OSIC-based one. Simulation results validate the theoretical conclusions with regard to both the performance and complexity of the proposed MIMO detection scheme. 展开更多
关键词 ordered successive noise projection cancellation(OSNPC) dual lattice reduction (DLR) multi-input multi-output (MIMO) detection ordered successive interferencecancellation (OSIC)
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Analysis of the Influence of Sound Source Position and Electrode Placement on the Stimulation Pattern of the Cochlear Implant under Noise Conditions: Optimization of Auditory Perceptual Effects
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作者 Johannes Burkart 《International Journal of Otolaryngology and Head & Neck Surgery》 2024年第3期194-212,共19页
Background: Cochlear implants (CI) are widely used to restore hearing in people with severe to profound hearing loss. However, optimizing CI performance, especially in difficult listening environments with background ... Background: Cochlear implants (CI) are widely used to restore hearing in people with severe to profound hearing loss. However, optimizing CI performance, especially in difficult listening environments with background noise, remains a major challenge. Understanding the influence of factors such as sound source position and electrode placement on CI stimulation patterns is critical to improving auditory perception. Methods: In this study, an analysis was conducted to investigate the influence of sound source position and electrode placement on CI stimulation patterns under noisy conditions. For this purpose, a special measurement setup with a CI speech processor-microphone test box was used to simulate realistic listening scenarios and measure CI performance. Results: The results show that the effectiveness of CI noise reduction systems is influenced by factors such as the position of the sound source and electrode placement. In particular, the beamforming ultra zoom mode showed significantly better noise reduction than the omnidirectional mode, especially under real listening conditions. Furthermore, differences in electrode responses indicate individual variability in the CI user experience, highlighting the importance of personalized fitting algorithms. Conclusions: The results demonstrate the importance of considering environmental factors and individual differences when optimizing CI performance. Future research efforts should focus on the development of personalized fitting algorithms and the exploration of innovative strategies, such as the integration of artificial intelligence, to improve CI functionality in different listening environments. This study contributes to our understanding of CI stimulation patterns and lays the foundation for improving auditory perception in CI users. 展开更多
关键词 Cochlear Implants noise reduction Ultra Zoom Beamforming Anatomical Variations Personalized Fittings
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Noise Reduction of an Axial Piston Pump by Valve Plate Optimization 被引量:20
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作者 Shao-Gan Ye Jun-Hui Zhang Bing Xu 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2018年第3期85-100,共16页
Current researches mainly focus on the investigations of the valve plate utilizing pressure relief grooves. However,air?release and cavitation can occur near the grooves. The valve plate utilizing damping holes show e... Current researches mainly focus on the investigations of the valve plate utilizing pressure relief grooves. However,air?release and cavitation can occur near the grooves. The valve plate utilizing damping holes show excellent perfor?mance in avoiding air?release and cavitation. This study aims to reduce the noise emitted from an axial piston pump using a novel valve plate utilizing damping holes. A dynamic pump model is developed,in which the fluid properties are carefully modeled to capture the phenomena of air release and cavitation. The causes of di erent noise sources are investigated using the model. A comprehensive parametric analysis is conducted to enhance the understanding of the e ects of the valve plate parameters on the noise sources. A multi?objective genetic algorithm optimization method is proposed to optimize the parameters of valve plate. The amplitudes of the swash plate moment and flow rates in the inlet and outlet ports are defined as the objective functions. The pressure overshoot and undershoot in the piston chamber are limited by properly constraining the highest and lowest pressure values. A comparison of the various noise sources between the original and optimized designs over a wide range of pressure levels shows that the noise sources are reduced at high pressures. The results of the sound pressure level measurements show that the optimized valve plate reduces the noise level by 1.6 d B(A) at the rated working condition. The proposed method is e ective in reducing the noise of axial piston pumps and contributes to the development of quieter axial piston machines. 展开更多
关键词 Axial piston pump noise reduction Fluid?borne noise Structure?borne noise Parametric analysis Multi?objective optimization
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A local f-x Cadzow method for noise reduction of seismic data obtained in complex formations 被引量:7
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作者 Yuan Sanyi Wang Shangxu 《Petroleum Science》 SCIE CAS CSCD 2011年第3期269-277,共9页
A noise-reduction method with sliding called the local f-x Cadzow noise-reduction method, windows in the frequency-space (f-x) domain, is presented in this paper. This method is based on the assumption that the sign... A noise-reduction method with sliding called the local f-x Cadzow noise-reduction method, windows in the frequency-space (f-x) domain, is presented in this paper. This method is based on the assumption that the signal in each window is linearly predictable in the spatial direction while the random noise is not. For each Toeplitz matrix constructed by constant frequency slice, a singular value decomposition (SVD) is applied to separate signal from noise. To avoid edge artifacts caused by zero percent overlap between windows and to remove more noise, an appropriate overlap is adopted. Besides flat and dipping events, this method can enhance curved and conflicting events. However, it is not suitable for seismic data that contains big spikes or null traces. It is also compared with the SVD, f-x deconvolution, and Cadzow method without windows. The comparison results show that the local Cadzow method performs well in removing random noise and preserving signal. In addition, a real data example proves that it is a potential noise-reduction technique for seismic data obtained in areas of complex formations. 展开更多
关键词 Cadzow sliding window noise reduction FIDELITY complex formations Toeplitz matrix singular value decomposition
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NOISE REDUCTION SCHEDULING METHOD IN A SHOP FLOOR AND ITS CASE STUDY 被引量:5
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作者 LiuFei CaoHuajun +1 位作者 ZhangHua YuanChuanping 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2003年第4期337-339,共3页
Noise reduction in a shop floor is one of the important parts of greenmanufacturing. In a shop floor machine tools are the main noise sources in a shop floor. A newapproach is discovered by investigation that the nois... Noise reduction in a shop floor is one of the important parts of greenmanufacturing. In a shop floor machine tools are the main noise sources in a shop floor. A newapproach is discovered by investigation that the noise can be obviously reduced in a shop floor byoptimizing the scheduling between work pieces and machine tools. Based on the discovery, a newmethod of noise reduction is proposed. A noise reduction scheduling model in a shop floor isestablished, and the application of the model is also discussed. A case is studied, which shows thatthe method and model are practical. 展开更多
关键词 Green manufacturing noise reduction SCHEDULING
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Use of a plane jet for flow-induced noise reduction of tandem rods 被引量:4
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作者 赵鲲 杨希祥 +1 位作者 Patrick N Okolo 张为华 《Chinese Physics B》 SCIE EI CAS CSCD 2016年第6期270-278,共9页
Unsteady wake from upstream components of landing gear impinging on downstream components could be a strong noise source.The use of a plane jet is proposed to reduce this flow-induced noise.Tandem rods with different ... Unsteady wake from upstream components of landing gear impinging on downstream components could be a strong noise source.The use of a plane jet is proposed to reduce this flow-induced noise.Tandem rods with different gap widths were utilized as the test body.Both acoustic and aerodynamic tests were conducted in order to validate this technique.Acoustic test results proved that overall noise emission from tandem rods could be lowered and tonal noise could be removed with use of the plane jet.However,when the plane jet was turned on,in some frequency range it could be the subsequent main contributor instead of tandem rods to total noise emission whilst in some frequency range rods could still be the main contributor.Moreover,aerodynamic tests fundamentally studied explanations for the noise reduction.Specifically,not only impinging speed to rods but speed and turbulence level to the top edge of the rear rod could be diminished by the upstream plane jet.Consequently,the vortex shedding induced by the rear rod was reduced,which was confirmed by the speed,Reynolds stress as well as the velocity fluctuation spectral measured in its wake.This study confirmed the potential use of a plane jet towards landing gear noise reduction. 展开更多
关键词 plane jet tandem rods flow-induced noise reduction vortex shedding
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A novel noise reduction technique for underwater acoustic signals based on complete ensemble empirical mode decomposition with adaptive noise,minimum mean square variance criterion and least mean square adaptive filter 被引量:8
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作者 Yu-xing Li Long Wang 《Defence Technology(防务技术)》 SCIE EI CAS CSCD 2020年第3期543-554,共12页
Underwater acoustic signal processing is one of the research hotspots in underwater acoustics.Noise reduction of underwater acoustic signals is the key to underwater acoustic signal processing.Owing to the complexity ... Underwater acoustic signal processing is one of the research hotspots in underwater acoustics.Noise reduction of underwater acoustic signals is the key to underwater acoustic signal processing.Owing to the complexity of marine environment and the particularity of underwater acoustic channel,noise reduction of underwater acoustic signals has always been a difficult challenge in the field of underwater acoustic signal processing.In order to solve the dilemma,we proposed a novel noise reduction technique for underwater acoustic signals based on complete ensemble empirical mode decomposition with adaptive noise(CEEMDAN),minimum mean square variance criterion(MMSVC) and least mean square adaptive filter(LMSAF).This noise reduction technique,named CEEMDAN-MMSVC-LMSAF,has three main advantages:(i) as an improved algorithm of empirical mode decomposition(EMD) and ensemble EMD(EEMD),CEEMDAN can better suppress mode mixing,and can avoid selecting the number of decomposition in variational mode decomposition(VMD);(ii) MMSVC can identify noisy intrinsic mode function(IMF),and can avoid selecting thresholds of different permutation entropies;(iii) for noise reduction of noisy IMFs,LMSAF overcomes the selection of deco mposition number and basis function for wavelet noise reduction.Firstly,CEEMDAN decomposes the original signal into IMFs,which can be divided into noisy IMFs and real IMFs.Then,MMSVC and LMSAF are used to detect identify noisy IMFs and remove noise components from noisy IMFs.Finally,both denoised noisy IMFs and real IMFs are reconstructed and the final denoised signal is obtained.Compared with other noise reduction techniques,the validity of CEEMDAN-MMSVC-LMSAF can be proved by the analysis of simulation signals and real underwater acoustic signals,which has the better noise reduction effect and has practical application value.CEEMDAN-MMSVC-LMSAF also provides a reliable basis for the detection,feature extraction,classification and recognition of underwater acoustic signals. 展开更多
关键词 Underwater acoustic signal noise reduction Empirical mode decomposition(EMD) Ensemble EMD(EEMD) Complete EEMD with adaptive noise(CEEMDAN) Minimum mean square variance criterion(MMSVC) Least mean square adaptive filter(LMSAF) Ship-radiated noise
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Noise Reduction of Welding Defect Image Based on NSCT and Anisotropic Diffusion 被引量:4
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作者 吴一全 万红 +1 位作者 叶志龙 刚铁 《Transactions of Tianjin University》 EI CAS 2014年第1期60-65,共6页
In order to reduce noise effectively in the welding defect image and preserve the minutiae information, a noise reduction method of welding defect image based on nonsubsampled contourlet transform(NSCT) and anisotropi... In order to reduce noise effectively in the welding defect image and preserve the minutiae information, a noise reduction method of welding defect image based on nonsubsampled contourlet transform(NSCT) and anisotropic diffusion is proposed. Firstly, an X-ray welding defect image is decomposed by NSCT. Then total variation(TV) model and Catte_PM model are used for the obtained low-pass component and band-pass components, respectively. Finally, the denoised image is synthesized by inverse NSCT. Experimental results show that, compared with the hybrid method of wavelet threshold shrinkage with TV diffusion, the method combining NSCT with P_Laplace diffusion, and the method combining contourlet with TV model and adaptive contrast diffusion, the proposed method has a great improvement in the aspects of subjective visual effect, peak signal-to-noise ratio(PSNR) and mean-square error(MSE). Noise is suppressed more effectively and the minutiae information is preserved better in the image. 展开更多
关键词 welding defect detection noise reduction nonsubsampled contourlet transform total variation model Catte_PM model
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A hypothesis study on bionic active noise reduction of auditory organs 被引量:1
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作者 Qing-Qing Jiang Ning Yu Shi-Ming Yang 《Military Medical Research》 SCIE CAS 2018年第2期178-182,共5页
Background:Noise exposure can lead to hearing loss and multiple system dysfunctions.As various forms of noise exist in our living environments,and our auditory organs are very sensitive to acoustic stimuli,it is a cha... Background:Noise exposure can lead to hearing loss and multiple system dysfunctions.As various forms of noise exist in our living environments,and our auditory organs are very sensitive to acoustic stimuli,it is a challenge to protect our hearing system in certain noisy environments.Presentation of the hypothesis:Herein,we propose that our hearing organ could serve as a noise eliminator for high intensity noise and enhance acoustic signal processing abilities by increasing the signal-noise ratio.For suprathreshold signals,the hearing system is capable of regulating the middle ear muscles and other structures to actively suppress the sound level to a safe range.Testing the hypothesis:To test our hypothesis,both mathematic model analyses and animal model studies are needed.Based on a digital 3D reconstructed model,every structure in the auditory system can be analyzed and tested for its contribution to the process of noise reduction.Products manufactured by this bionic method could be used and verified in animal models and volunteers.Implications:By mimicking the noise-reduction effect of the sophisticated structures in the hearing system,we may be able to provide a model that establishes a new active-sound-suppression mode.This innovative method may overcome the limited capabilities of current noise protection options and become a promising possibility for noise prevention. 展开更多
关键词 ACTIVE noise reduction BIONIC HEARING LOSS
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A CROSS-REFERENCE METHOD OF PARAMETER ESTIMATION AND NOISE REDUCTION AND ITS APPLICATIONS 被引量:1
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作者 Yang Luxi Chen Yang He Zhenya(Department of Radio Engineering, Southeast University, Nanjing 210096) 《Journal of Electronics(China)》 1999年第3期238-243,共6页
This paper proposes a cross-reference method of nonlinear time series analysis, combining the tasks of dynamical system parameter estimation and noise reduction which were fulfilled separately before. With the positiv... This paper proposes a cross-reference method of nonlinear time series analysis, combining the tasks of dynamical system parameter estimation and noise reduction which were fulfilled separately before. With the positive interaction between the two processing modules, the method is somewhat superior. Some prior works can be viewed as special cases of this general framework and effective new algorithms may be devised according to it. Two examples of chaotic time series analysis are also given to show the applicability of the proposed method. 展开更多
关键词 PARAMETER ESTIMATION noise reduction Cross-reference
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Reduction of the Clipping Noise for OFDM/OQAM System 被引量:2
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作者 Guobing Cheng Qifu Lv +3 位作者 Shaoqian Li Lisha Gong Binhong Dong Su Hu 《Communications and Network》 2013年第3期394-397,共4页
Orthogonal frequency division multiplex/offset QAM (OFDM/OQAM) has been proven to be a promising multi-carrier modulation (MCM) technique for the transmission of signals over multipath fading channels. However, OFDM/O... Orthogonal frequency division multiplex/offset QAM (OFDM/OQAM) has been proven to be a promising multi-carrier modulation (MCM) technique for the transmission of signals over multipath fading channels. However, OFDM/OQAM has also the intrinsic disadvantage of high peak-to-average-power ratio (PAPR) that should be alleviated. This paper focuses on the reduction of the clipping noise and out-of band radiation caused by the clipping process. The basic principle is to estimate the clipping noise and then eliminate it from the received signal. Analysis and simulation results show that, with one time iteration, the proposed method can effectively improve the bit error ratio (BER) performance. 展开更多
关键词 OFDM/OQAM PAPR reduction CLIPPING noise
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Noise in nanopore sensors: Sources, models, reduction, and benchmarking 被引量:1
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作者 Shengfa Liang Feibin Xiang +4 位作者 Zifan Tang Reza Nouri Xiaodong He Ming Dong Weihua Guan 《Nanotechnology and Precision Engineering》 EI CAS CSCD 2020年第1期9-17,共9页
Label-free nanopore sensors have emerged as a new generation technology of DNA sequencing and have been widely used for single molecule analysis.Since the firstα-hemolysin biological nanopore,various types of nanopor... Label-free nanopore sensors have emerged as a new generation technology of DNA sequencing and have been widely used for single molecule analysis.Since the firstα-hemolysin biological nanopore,various types of nanopores made of different materials have been under extensive development.Noise represents a common challenge among all types of nanopore sensors.The nanopore noise can be decomposed into four components in the frequency domain(1/f noise,white noise,dielectric noise,and amplifier noise).In this work,we reviewed and summarized the physicalmodels,origins,and reduction methods for each of these noise components.For the first time,we quantitatively benchmarked the root mean square(RMS)noise levels for different types of nanopores,demonstrating a clear material-dependent RMS noise.We anticipate this review article will enhance the understanding of nanopore sensor noises and provide an informative tutorial for developing future nanopore sensors with a high signal-to-noise ratio. 展开更多
关键词 noise NANOPORE Model Material noise reduction
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Evaluation of Diesel Engine Noise Reduction Measures Based on Hierarchy Diagnosis 被引量:1
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作者 梁兴雨 舒歌群 +1 位作者 卫海桥 陈达亮 《Transactions of Tianjin University》 EI CAS 2007年第3期205-210,共6页
Effect of different noise reduction measures for diesel engines was evaluated based on hierarchy diagnosis. The hierarchy diagnosis chart and hierarchy judgment matrix were given. Through evaluation of noise reduction... Effect of different noise reduction measures for diesel engines was evaluated based on hierarchy diagnosis. The hierarchy diagnosis chart and hierarchy judgment matrix were given. Through evaluation of noise reduction measures, the main strategies of noise reduction were found. The result shows that the noise reduction level of different frequency belts varies from measure to measure. The reduction capacity of different measures could not add simply, which relates to the problem of parameter matching. 展开更多
关键词 diesel engine hierarchy diagnosis noise reduction power spectrum
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DNN-Based Speech Enhancement Using Soft Audible Noise Masking for Wind Noise Reduction 被引量:1
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作者 Haichuan Bai Fengpei Ge Yonghong Yan 《China Communications》 SCIE CSCD 2018年第9期235-243,共9页
This paper presents a deep neural network(DNN)-based speech enhancement algorithm based on the soft audible noise masking for the single-channel wind noise reduction. To reduce the low-frequency residual noise, the ps... This paper presents a deep neural network(DNN)-based speech enhancement algorithm based on the soft audible noise masking for the single-channel wind noise reduction. To reduce the low-frequency residual noise, the psychoacoustic model is adopted to calculate the masking threshold from the estimated clean speech spectrum. The gain for noise suppression is obtained based on soft audible noise masking by comparing the estimated wind noise spectrum with the masking threshold. To deal with the abruptly time-varying noisy signals, two separate DNN models are utilized to estimate the spectra of clean speech and wind noise components. Experimental results on the subjective and objective quality tests show that the proposed algorithm achieves the better performance compared with the conventional DNN-based wind noise reduction method. 展开更多
关键词 wind noise reduction speech enhancement soft audible noise masking psychoacoustic model deep neural network
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Investigation and Reduction on Conducted Electromagnetic Interference Noise Mechanism for Complex Power Electronics Systems 被引量:4
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作者 YAN Wei ZHAO Yang +4 位作者 WANG Ertrong ZHANG Yuhuan QIU Xiaohui SUN Hongyan CHEN Xueli 《中国电机工程学报》 EI CSCD 北大核心 2012年第30期I0022-I0022,24,共1页
针对复杂电子系统产生的传导EMI噪声,该文分别利用电偶极子模型、电路分析方法和散射参数方法提出了3种传导EMI噪声理论模型及其等效电路,包括因串扰引起的传导噪声模型,因接地不良引起的传导噪声模型,以及因PCB线缆阻抗失配引起的传导... 针对复杂电子系统产生的传导EMI噪声,该文分别利用电偶极子模型、电路分析方法和散射参数方法提出了3种传导EMI噪声理论模型及其等效电路,包括因串扰引起的传导噪声模型,因接地不良引起的传导噪声模型,以及因PCB线缆阻抗失配引起的传导噪声模型。同时,还设计了一种串扰扼流圈以有效抑制因串扰引起的传导EMI噪声。实验结果表明,采用文中方法,某型商用车载导航和刷卡器能够通过GB 9254标准测试,噪声抑制效果分别可达44.8和29.28 dB V,从而验证了方法的有效性。 展开更多
关键词 传导电磁干扰 电力电子系统 噪声机理 共模扼流圈 噪声分离 和差模 EMI 电容
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Research on Noise Reduction Approach of Raman-Based Distributed Temperature Sensor Based on Nonlinear Filter 被引量:1
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作者 Xiang Wang Tong Liu Honghui Wang 《Open Journal of Applied Sciences》 2019年第8期631-639,共9页
The accuracy of temperature measurement is often reduced due to random noise in Raman-based distributed temperature sensor (RDTS). A noise reduction method based on a nonlinear filter is thus proposed in this paper. C... The accuracy of temperature measurement is often reduced due to random noise in Raman-based distributed temperature sensor (RDTS). A noise reduction method based on a nonlinear filter is thus proposed in this paper. Compared with the temperature demodulation results of raw signals, the proposed method in this paper can reduce the average maximum deviation of temperature measurement results from 4.1°C to 1.2°C at 40.0°C, 50.0°C and 60.0°C. And the proposed method in this paper can improve the accuracy of temperature measurement of Raman-based distributed temperature sensor better than the commonly used wavelet transform-based method. The advantages of the proposed method in improving the accuracy of temperature measurement for Raman-based distributed temperature sensor are quantitatively reflected in the maximum deviation and root mean square error of temperature measurement results. Therefore, this paper proposes an effective and feasible method to improve the accuracy of temperature measurement results for Raman-based distributed temperature sensor. 展开更多
关键词 Raman-Based Distributed TEMPERATURE SENSOR noise reduction TEMPERATURE Measurement
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Joint Noise Reduction and lp-Norm Minimization for Enhancing Time Delay Estimation in Colored Noise 被引量:1
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作者 Jingxian Tu Youshen Xia 《Journal of Computer and Communications》 2016年第3期46-53,共8页
Time delay estimation (TDE) is an important issue in signal processing. Conventional TDE algorithms are usually efficient under white noise environments. In this paper, a joint noise reduction and -norm minimization m... Time delay estimation (TDE) is an important issue in signal processing. Conventional TDE algorithms are usually efficient under white noise environments. In this paper, a joint noise reduction and -norm minimization method is presented to enhance TDE in colored noise. An improved subspace method for colored noise reduction is first performed. Then the time delay is estimated by using an -norm minimization method. Because the clean speech signal form the noisy signal is well extracted by noise reduction and the -norm minimization method is robust, the TDE accuracy can be enhanced. Experiment results confirm that the proposed joint estimation method obtains more accurate TDE than several conventional algorithms in colored noise, especially in the case of low signal-to-noise ratio.   展开更多
关键词 Time Delay Estimation Speech Enhancement noise reduction SUBSPACE
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Low frequency noise reduction using stiff light composite panels
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作者 DENG Yongchang, LIN Weizheng (Institute of Acoustics, Tongji University, Shanghai 200092, China) 《声学技术》 CSCD 2003年第z1期28-36,共9页
The experiment presented in this paper is to investigate and analyze the noise reduction at low frequency using stiff light composite panels. Since these composite panels are made of lightweight and stiff materials, t... The experiment presented in this paper is to investigate and analyze the noise reduction at low frequency using stiff light composite panels. Since these composite panels are made of lightweight and stiff materials, this actuation strategy will enable the creation of composite panels for duct noise control without using traditional heavy structural mass. The results suggest that the mass-spring resonance absorption in the case of a comparatively stiff thick panel with a thin flexible plate is more efficient with minimum weight, when subjected to low-frequency (<500 Hz). The efficiency of the panel absorber depends on the mass of the thin flexible plate and the stiffness of the panel. 展开更多
关键词 low frequency STIFF COMPOSITE panels noise reduction
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Hybrid device for acoustic noise reduction and energy harvesting based on a silicon micro-perforated panel structure
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作者 吴少华 杜利东 +3 位作者 孔德义 平皓月 方震 赵湛 《Chinese Physics B》 SCIE EI CAS CSCD 2014年第4期351-357,共7页
A kind of hybrid device for acoustic noise reduction and vibration energy harvesting based on the silicon micro- perforated panel (MPP) resonant structure is investigated in the article. The critical parts of the de... A kind of hybrid device for acoustic noise reduction and vibration energy harvesting based on the silicon micro- perforated panel (MPP) resonant structure is investigated in the article. The critical parts of the device include MPP and energy harvesting membranes. They are all fabricated by means of silicon micro-electro-mechanical systems (MEMS) tech- nology. The silicon MPP has dense and accurate micro-holes. This noise reduction structure has the advantages of wide band and higher absorption coefficients. The vibration energy harvesting part is formed by square piezoelectric membranes arranged in rows. ZnO material is used as it has a good compatibility with the fabrication process. The MPP, piezo- electric membranes, and metal bracket are assembled into a hybrid device with multifunctions. The device exhibits good performances of acoustic noise absorption and acoustic-electric conversion. Its maximum open circuit voltage achieves 69.41 mV. 展开更多
关键词 hybrid device noise energy harvesting acoustic noise reduction silicon micro-perforated panel
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