A class of multistage filters, namely, real narrowband bandpass filter （RNBPF） has been previously used for identification of protein coding regions. This filter passes the frequency component at 2π/3 along with it...A class of multistage filters, namely, real narrowband bandpass filter （RNBPF） has been previously used for identification of protein coding regions. This filter passes the frequency component at 2π/3 along with its conjugate. This conjugate frequency compo- nent may degrade the identification accuracy. To improve the identification accuracy, two types of multistage filters are proposed in this paper. A complex narrowband bandpass filter （CNBPF） is proposed for suppressing the conjugate frequency component which, in turn, reduces the background noise present in the deoxyribonucleic acid （DNA） spec- trum and improves identification accuracy. By cascading RNBPF with moving average filter （RNBPFMA）, another type of multistage filter is proposed. As moving average filter smooth out the rapid variations in the DNA spectrum, RNBPFMA improves the identification accuracy. The computational complexity of RNBPFMA is less than that of CNBPF. The RNBPF and proposed multistage filters are compared with previously reported short-time discrete Fourier transform （ST-DFT） method in terms of compu- tational complexity. It is found that multistage filters reduce the computational load to a greater extent compared to ST-DFT method. The identification accuracy of the proposed CNBPF and RNBPFMA methods is compared with existing anti-notch filter and RNBPF methods. The results show that proposed methods outperform existing methods in terms of identification accuracy for benchmark data sets.展开更多
We propose a compact dual-band bandpass filter(BPF)based on one-dimensional porous silicon(PS)photonic crystal by electrochemical etching.By inserting three periods of high and low reflective index layers in the cente...We propose a compact dual-band bandpass filter(BPF)based on one-dimensional porous silicon(PS)photonic crystal by electrochemical etching.By inserting three periods of high and low reflective index layers in the center of porous silicon microcavity(PSM),two sharp resonant peaks appear in the high reflectivity stop band on both sides of the resonance wavelength.Through simulation and experiment,the physical mechanisms of the two resonance peaks and the resonance wavelength are also studied.It is found that the resonance wavelength can be tuned only by adjusting the effective optical thickness(EOT)of each PS layer,in which different resonance wavelengths have different widths between the two sharp resonance peaks.Besides,the analysis indicates that oxidization makes the blue shift become larger for high wavelength than that for low wavelength.Such a fabricated BPF based on PS dual-microcavity is easy to be fabricated and low cost,which benefits the application of integrated optical devices.展开更多
文摘A class of multistage filters, namely, real narrowband bandpass filter （RNBPF） has been previously used for identification of protein coding regions. This filter passes the frequency component at 2π/3 along with its conjugate. This conjugate frequency compo- nent may degrade the identification accuracy. To improve the identification accuracy, two types of multistage filters are proposed in this paper. A complex narrowband bandpass filter （CNBPF） is proposed for suppressing the conjugate frequency component which, in turn, reduces the background noise present in the deoxyribonucleic acid （DNA） spec- trum and improves identification accuracy. By cascading RNBPF with moving average filter （RNBPFMA）, another type of multistage filter is proposed. As moving average filter smooth out the rapid variations in the DNA spectrum, RNBPFMA improves the identification accuracy. The computational complexity of RNBPFMA is less than that of CNBPF. The RNBPF and proposed multistage filters are compared with previously reported short-time discrete Fourier transform （ST-DFT） method in terms of compu- tational complexity. It is found that multistage filters reduce the computational load to a greater extent compared to ST-DFT method. The identification accuracy of the proposed CNBPF and RNBPFMA methods is compared with existing anti-notch filter and RNBPF methods. The results show that proposed methods outperform existing methods in terms of identification accuracy for benchmark data sets.
基金supported by the National Training Program of Innovation and Entrepreneurship for Undergraduate(No.201410755013)the Foundation of Xinjiang Education(No.XJEDU2013S04)
文摘We propose a compact dual-band bandpass filter(BPF)based on one-dimensional porous silicon(PS)photonic crystal by electrochemical etching.By inserting three periods of high and low reflective index layers in the center of porous silicon microcavity(PSM),two sharp resonant peaks appear in the high reflectivity stop band on both sides of the resonance wavelength.Through simulation and experiment,the physical mechanisms of the two resonance peaks and the resonance wavelength are also studied.It is found that the resonance wavelength can be tuned only by adjusting the effective optical thickness(EOT)of each PS layer,in which different resonance wavelengths have different widths between the two sharp resonance peaks.Besides,the analysis indicates that oxidization makes the blue shift become larger for high wavelength than that for low wavelength.Such a fabricated BPF based on PS dual-microcavity is easy to be fabricated and low cost,which benefits the application of integrated optical devices.
