This paper shows the presence of noises and technique to reduce these noises during the surface wave analysis. The frequency-dependent properties of Rayleigh-type surface waves can be used for imaging and characterizi...This paper shows the presence of noises and technique to reduce these noises during the surface wave analysis. The frequency-dependent properties of Rayleigh-type surface waves can be used for imaging and characterizing the shallow subsurface. Interference by coherent source-generated noise inhibits the reliability of shear-wave velocities determined through inversion of the phase velocities of Rayleigh waves. Among these interferences by non-planar, non-fundamental mode Rayleigh waves （noise） are body waves, scattered and non-source-generated surface waves, and highermode surface waves. For the reduction of noise, the filtering technique is implemented in this paper for the multichannel analysis of surface wave method （MASW）. With the de-noising technique during the MASW method, more robust and reliable outcome is achieved. The significance of this paper is to obtain pre-awareness about noises during surface wave analysis and take better outcomes with denoising performance in near surface soil investigations.展开更多
With the constantly changing engineering construction sector,the detection accuracy of conventional electrical resistivity tomography(ERT)is no longer sufficient.A multichannel electrode design(MERT)-based ERT is intr...With the constantly changing engineering construction sector,the detection accuracy of conventional electrical resistivity tomography(ERT)is no longer sufficient.A multichannel electrode design(MERT)-based ERT is introduced in this paper to address the growing need for resolution.The imaging accuracy of the ERT method is improved through the collection of apparent resistivity data in various directions by measuring the potential diff erence between diff erent channels.Numerical simulation results of the inclined high-resistivity anomaly model reveal that MERT is a precise representation of the shape,inclined direction,and buried depth of the anomaly,with thoroughfare M2N2 producing the most precise forward and inverse results.Based on the analysis results of the model resolution matrix,when the buried depth of power supply points and the gap between potential acquisition points are 30%-90%and 30%-60%of the electrode distance,respectively,the MERT approach yields superior detection outcomes.The detection eff ect of the MERT method on anomalous bodies with diff erent burial depths under the optimal parameters also indicates that the MERT method can obtain richer potential change information with higher resolution in deep areas compared to the ERT method.With the implementation of the MERT approach,the scope of applications for ERT is expanded,the accuracy of ERT detection is increased,and the progress of near-surface fine detection is positively infl uenced.展开更多
A new method in digital hearing aids to adaptively localize the speech source in noise and reverberant environment is proposed. Based on the room reverberant model and the multichannel adaptive eigenvalue decompositi...A new method in digital hearing aids to adaptively localize the speech source in noise and reverberant environment is proposed. Based on the room reverberant model and the multichannel adaptive eigenvalue decomposition （MCAED） algorithm, the proposed method can iteratively estimate impulse response coefficients between the speech source and microphones by the adaptive subgradient projection method. Then, it acquires the time delays of microphone pairs, and calculates the source position by the geometric method. Compared with the traditional normal least mean square （NLMS） algorithm, the adaptive subgradient projection method achieves faster and more accurate convergence in a low signal-to-noise ratio （SNR） environment. Simulations for glasses digital hearing aids with four-component square array demonstrate the robust performance of the proposed method.展开更多
高光谱图像异常检测作为一种无监督的目标检测,主要存在异常目标类型多样化、异常与背景不易区分、以及检测精度受场景影响大等难题。针对以上问题,本文提出了一种基于空谱多路自编码器的高光谱图像异常检测方法。首先,提出一种加权空谱...高光谱图像异常检测作为一种无监督的目标检测,主要存在异常目标类型多样化、异常与背景不易区分、以及检测精度受场景影响大等难题。针对以上问题,本文提出了一种基于空谱多路自编码器的高光谱图像异常检测方法。首先,提出一种加权空谱Gabor滤波方法,提取高光谱图像的多尺度空谱特征;其次,采用多路自编码器降低多尺度空谱特征在光谱维的冗余度,提取空谱特征中的主要信息;最后,利用得到的主要空谱特征,结合形态学滤波与双曲正切函数进行特征增强,以提高异常与背景噪声的区分度。本文提出的方法是一种即插即用的异常检测方法,无需额外的参数输入;多路自编码器提取了多尺度主要空谱特征,以应对异常目标类型多样化的难题;通过特征增强提高了背景与异常的区分度。将本文提出的方法与9种流行的异常检测方法相比,在5个高光谱数据集上进行验证,通过对比异常检测结果图、接收机操作特性(Receiver Operating Characteristic,ROC)曲线、ROC曲线下覆盖的面积AUC(Area Under Curve)以及异常像元与背景像元的箱型图等评价指标,证明了本文方法优于其他9种方法。展开更多
基金supported by Research Project of Science Fund No. 01-01-02-SF0338Science Fund No.01-01-02-SF0681 from Ministry of Science, Technologyand Innovation of Malaysia
文摘This paper shows the presence of noises and technique to reduce these noises during the surface wave analysis. The frequency-dependent properties of Rayleigh-type surface waves can be used for imaging and characterizing the shallow subsurface. Interference by coherent source-generated noise inhibits the reliability of shear-wave velocities determined through inversion of the phase velocities of Rayleigh waves. Among these interferences by non-planar, non-fundamental mode Rayleigh waves （noise） are body waves, scattered and non-source-generated surface waves, and highermode surface waves. For the reduction of noise, the filtering technique is implemented in this paper for the multichannel analysis of surface wave method （MASW）. With the de-noising technique during the MASW method, more robust and reliable outcome is achieved. The significance of this paper is to obtain pre-awareness about noises during surface wave analysis and take better outcomes with denoising performance in near surface soil investigations.
基金supported by the National Key Research and Development Program of China(Grant No.2021YFC3000103)the National Natural Science Foundation of China(Grant No.41504081)。
文摘With the constantly changing engineering construction sector,the detection accuracy of conventional electrical resistivity tomography(ERT)is no longer sufficient.A multichannel electrode design(MERT)-based ERT is introduced in this paper to address the growing need for resolution.The imaging accuracy of the ERT method is improved through the collection of apparent resistivity data in various directions by measuring the potential diff erence between diff erent channels.Numerical simulation results of the inclined high-resistivity anomaly model reveal that MERT is a precise representation of the shape,inclined direction,and buried depth of the anomaly,with thoroughfare M2N2 producing the most precise forward and inverse results.Based on the analysis results of the model resolution matrix,when the buried depth of power supply points and the gap between potential acquisition points are 30%-90%and 30%-60%of the electrode distance,respectively,the MERT approach yields superior detection outcomes.The detection eff ect of the MERT method on anomalous bodies with diff erent burial depths under the optimal parameters also indicates that the MERT method can obtain richer potential change information with higher resolution in deep areas compared to the ERT method.With the implementation of the MERT approach,the scope of applications for ERT is expanded,the accuracy of ERT detection is increased,and the progress of near-surface fine detection is positively infl uenced.
基金Supported by the National Natural Science Foundation of China (60872073)~~
文摘A new method in digital hearing aids to adaptively localize the speech source in noise and reverberant environment is proposed. Based on the room reverberant model and the multichannel adaptive eigenvalue decomposition （MCAED） algorithm, the proposed method can iteratively estimate impulse response coefficients between the speech source and microphones by the adaptive subgradient projection method. Then, it acquires the time delays of microphone pairs, and calculates the source position by the geometric method. Compared with the traditional normal least mean square （NLMS） algorithm, the adaptive subgradient projection method achieves faster and more accurate convergence in a low signal-to-noise ratio （SNR） environment. Simulations for glasses digital hearing aids with four-component square array demonstrate the robust performance of the proposed method.
文摘高光谱图像异常检测作为一种无监督的目标检测,主要存在异常目标类型多样化、异常与背景不易区分、以及检测精度受场景影响大等难题。针对以上问题,本文提出了一种基于空谱多路自编码器的高光谱图像异常检测方法。首先,提出一种加权空谱Gabor滤波方法,提取高光谱图像的多尺度空谱特征;其次,采用多路自编码器降低多尺度空谱特征在光谱维的冗余度,提取空谱特征中的主要信息;最后,利用得到的主要空谱特征,结合形态学滤波与双曲正切函数进行特征增强,以提高异常与背景噪声的区分度。本文提出的方法是一种即插即用的异常检测方法,无需额外的参数输入;多路自编码器提取了多尺度主要空谱特征,以应对异常目标类型多样化的难题;通过特征增强提高了背景与异常的区分度。将本文提出的方法与9种流行的异常检测方法相比,在5个高光谱数据集上进行验证,通过对比异常检测结果图、接收机操作特性(Receiver Operating Characteristic,ROC)曲线、ROC曲线下覆盖的面积AUC(Area Under Curve)以及异常像元与背景像元的箱型图等评价指标,证明了本文方法优于其他9种方法。
