Stochastic noises of fiber optic gyroscope （FOG） mainly contain white noise and fractal noise whose long-term dependent component causes FOG a rather slow drift. In order to eliminate this component, a two-step filt...Stochastic noises of fiber optic gyroscope （FOG） mainly contain white noise and fractal noise whose long-term dependent component causes FOG a rather slow drift. In order to eliminate this component, a two-step filtering methodology is proposed. Firstly, fractional differencing （FD） method is introduced to trans-form fractal noise into fractional white noise based on the estima-tion of Hurst exponent for long-term dependent fractal process, which together with the existing white noise make up of a gener-alized white noise. Further, an improved denoising algorithm of wavelet maxima is developed to suppress the generalized white noise. Experimental results show that the basic noise terms of FOG greatly decrease, and especially the slow drift is restrained effectively. The proposed methodology provides a promising ap-proach for filtering long-term dependent fractal noise.展开更多
The self similarity of the network traffic has great influences on the performance. But there are few analytical or even numerical solutions for such a model. So simulation becomes the most efficient method for resear...The self similarity of the network traffic has great influences on the performance. But there are few analytical or even numerical solutions for such a model. So simulation becomes the most efficient method for research. Fractal Gaussian noise (FGN) is the most popularly used self similar model. This paper presented an FGN generator based on fast Fourier transform (FFT). The study indicates that this algorithm is fairly fast and accurate.展开更多
On the basis of the fractal geometry, a nactional Brownian Motion (FBM) model for the noise radiated by ship was established, under which its fractal dimension has been obtained and the Fractal Characteristic Vector (...On the basis of the fractal geometry, a nactional Brownian Motion (FBM) model for the noise radiated by ship was established, under which its fractal dimension has been obtained and the Fractal Characteristic Vector (FCV) was constructed in the fractional Brownian random field (FBRF). By using of them, a new technique of the characteristic analysis for target recognition in the underwater acoustics was presented. A comparative experiment for classification shows us that the FCV can be used as essential quantity by which some defects existing in the methods to do the characteristic extraction elsewhere can be remedied.展开更多
基金supported by Aviation Science Foundation(20070851011).
文摘Stochastic noises of fiber optic gyroscope （FOG） mainly contain white noise and fractal noise whose long-term dependent component causes FOG a rather slow drift. In order to eliminate this component, a two-step filtering methodology is proposed. Firstly, fractional differencing （FD） method is introduced to trans-form fractal noise into fractional white noise based on the estima-tion of Hurst exponent for long-term dependent fractal process, which together with the existing white noise make up of a gener-alized white noise. Further, an improved denoising algorithm of wavelet maxima is developed to suppress the generalized white noise. Experimental results show that the basic noise terms of FOG greatly decrease, and especially the slow drift is restrained effectively. The proposed methodology provides a promising ap-proach for filtering long-term dependent fractal noise.
文摘The self similarity of the network traffic has great influences on the performance. But there are few analytical or even numerical solutions for such a model. So simulation becomes the most efficient method for research. Fractal Gaussian noise (FGN) is the most popularly used self similar model. This paper presented an FGN generator based on fast Fourier transform (FFT). The study indicates that this algorithm is fairly fast and accurate.
文摘On the basis of the fractal geometry, a nactional Brownian Motion (FBM) model for the noise radiated by ship was established, under which its fractal dimension has been obtained and the Fractal Characteristic Vector (FCV) was constructed in the fractional Brownian random field (FBRF). By using of them, a new technique of the characteristic analysis for target recognition in the underwater acoustics was presented. A comparative experiment for classification shows us that the FCV can be used as essential quantity by which some defects existing in the methods to do the characteristic extraction elsewhere can be remedied.
