In this paper, a high-performance and low-complexity luminance transient improvement （LTI） algorithm is proposed and efficiently implemented on field programmable gate army （FPGA） devices, which can be widely used...In this paper, a high-performance and low-complexity luminance transient improvement （LTI） algorithm is proposed and efficiently implemented on field programmable gate army （FPGA） devices, which can be widely used to enhance the sharpness of digital video. The proposed algorithm generates the cor- rection signal by using the difference of the outputs of two Gaussian filters with different variances, and then modulates the correction signal adaptively according to the local contrast information of video frames. A 2-D min/max nonlinear filter is employed to suppress overshoots around edges. The proposed algorithm is thoroughly confirmed by experiments and compared with other algorithms on irrkages, which produces steeper edges and better visual quality while suppressing noise and artifacts. And the hardware architecture suitable for FPGA implementation is optimized based on the property of the algorithm and proves to be effective and efficient in many respects, such as resource consumption, performance and reconfigura- bility. The specific implementation details on both Xilinx and Ahera FPGA devices are also described in this paper.展开更多
A new S-type of erbium-ytterbium co-doped phosphate glass waveguide amplifier integrated with cascaded multilayer medium thin film filter is proposed,this S-type geometry waveguide structure is used to achieve a long ...A new S-type of erbium-ytterbium co-doped phosphate glass waveguide amplifier integrated with cascaded multilayer medium thin film filter is proposed,this S-type geometry waveguide structure is used to achieve a long path in a compact chip,and obtained higher gain with lower Er-doped concentration. The cascaded multilayer medium thin film filter is utilized to achieve a broader flattening gain bandwidth.The intrinsical gain spectrum is obtained by solving rate and power propagation equations,the effect of transmittance spectrum of thin film filter on flattening gain is discussed.展开更多
A general multiple-loop feedback approach for realization of Four-Terminal Floating Nullor RC(FTFN-RC) filter is presented.The proposed filter is constructed by multi-output FTFNs, capacitors and resistors.It can simu...A general multiple-loop feedback approach for realization of Four-Terminal Floating Nullor RC(FTFN-RC) filter is presented.The proposed filter is constructed by multi-output FTFNs, capacitors and resistors.It can simultaneously realize slow-pass, band-pass(if order is even number), and high-pass filter responses.With RC elements grounded and requiring no component matching con-straints, it is fully integrated conveniently.Simulations are performed for the fourth-order Butterworth filter to verify the validity of the circuit.展开更多
An algorithm for detecting low-frequency seismic events is developed and applied to the detection of low-frequency events before the 2008 Wenchuan and the 2013 Lushan earthquakes. Continuous vertical-component wavefor...An algorithm for detecting low-frequency seismic events is developed and applied to the detection of low-frequency events before the 2008 Wenchuan and the 2013 Lushan earthquakes. Continuous vertical-component waveforms of some broadband stations in the few months before the Wenchuan and Lushan earthquakes are processed by applying a bandpass filter in 2- 8Hz,and then converted to envelopes with a smoothing time of 10 s window and a median filter with a 20 min window. As a result,teleseismic,long-period noise and local small earthquakes are removed,the filtered amplitude is obviously larger than that of the noise and lasts for a dozen minutes to several hours during a few days in a few stations before the Wenchuan and Lushan earthquakes,respectively. The waveform and envelope are similar to that of a non-volcanic tremor( NVT). There are suspected NVT before the two earthquakes. Preliminary application demonstrates that this algorithm is potentially useful for extracting NVT signals from continuous seismic waveforms.展开更多
Subwavelength grating(SWG) waveguides in silicon-on-insulator are emerging as an enabling technology for implementing compact, high-performance photonic integrated devices and circuits for signal processing and sensin...Subwavelength grating(SWG) waveguides in silicon-on-insulator are emerging as an enabling technology for implementing compact, high-performance photonic integrated devices and circuits for signal processing and sensing applications. We provide an overview of our recent work on developing wavelength selective SWG waveguide filters based on Bragg gratings and ring resonators, as well as optical delay lines. These components increase the SWG waveguide component toolbox and can be used to realize more complex photonic integrated circuits with enhanced or new functionality.展开更多
Since novel optoelectronic devices based on the peculiar behaviors of the tunneling probability, e.g., resonant tunneling devices (RTD) and band-pass filter, are steadily proposed, the analytic transfer matrix (ATM) m...Since novel optoelectronic devices based on the peculiar behaviors of the tunneling probability, e.g., resonant tunneling devices (RTD) and band-pass filter, are steadily proposed, the analytic transfer matrix (ATM) method is extended to study these devices. For several examples, we explore the effect of the scattered subwaves on tunneling; it is shown that the resonant or band-pass structures in tunneling probability are determined by the phase shift results from the scattered subwaves.展开更多
基金Supported by the National Science and Technology Support Projects Funded by Ministry of Science & Technology of China (No. 2006BAK07B04)
文摘In this paper, a high-performance and low-complexity luminance transient improvement （LTI） algorithm is proposed and efficiently implemented on field programmable gate army （FPGA） devices, which can be widely used to enhance the sharpness of digital video. The proposed algorithm generates the cor- rection signal by using the difference of the outputs of two Gaussian filters with different variances, and then modulates the correction signal adaptively according to the local contrast information of video frames. A 2-D min/max nonlinear filter is employed to suppress overshoots around edges. The proposed algorithm is thoroughly confirmed by experiments and compared with other algorithms on irrkages, which produces steeper edges and better visual quality while suppressing noise and artifacts. And the hardware architecture suitable for FPGA implementation is optimized based on the property of the algorithm and proves to be effective and efficient in many respects, such as resource consumption, performance and reconfigura- bility. The specific implementation details on both Xilinx and Ahera FPGA devices are also described in this paper.
文摘A new S-type of erbium-ytterbium co-doped phosphate glass waveguide amplifier integrated with cascaded multilayer medium thin film filter is proposed,this S-type geometry waveguide structure is used to achieve a long path in a compact chip,and obtained higher gain with lower Er-doped concentration. The cascaded multilayer medium thin film filter is utilized to achieve a broader flattening gain bandwidth.The intrinsical gain spectrum is obtained by solving rate and power propagation equations,the effect of transmittance spectrum of thin film filter on flattening gain is discussed.
基金Supported by the Hunan Province Project of Education Department of Financial Aid (No.04C346)
文摘A general multiple-loop feedback approach for realization of Four-Terminal Floating Nullor RC(FTFN-RC) filter is presented.The proposed filter is constructed by multi-output FTFNs, capacitors and resistors.It can simultaneously realize slow-pass, band-pass(if order is even number), and high-pass filter responses.With RC elements grounded and requiring no component matching con-straints, it is fully integrated conveniently.Simulations are performed for the fourth-order Butterworth filter to verify the validity of the circuit.
基金funded by the National Science & Technology Pillar Program in the 12th "Five-year Plan" Period,China(2012BAKI9B02)
文摘An algorithm for detecting low-frequency seismic events is developed and applied to the detection of low-frequency events before the 2008 Wenchuan and the 2013 Lushan earthquakes. Continuous vertical-component waveforms of some broadband stations in the few months before the Wenchuan and Lushan earthquakes are processed by applying a bandpass filter in 2- 8Hz,and then converted to envelopes with a smoothing time of 10 s window and a median filter with a 20 min window. As a result,teleseismic,long-period noise and local small earthquakes are removed,the filtered amplitude is obviously larger than that of the noise and lasts for a dozen minutes to several hours during a few days in a few stations before the Wenchuan and Lushan earthquakes,respectively. The waveform and envelope are similar to that of a non-volcanic tremor( NVT). There are suspected NVT before the two earthquakes. Preliminary application demonstrates that this algorithm is potentially useful for extracting NVT signals from continuous seismic waveforms.
基金supported in part by the NSERC NGON and Si EPIC CREATE programs,NSERC SPG,and the Royal Society International Exchanges Scheme 2012/R2
文摘Subwavelength grating(SWG) waveguides in silicon-on-insulator are emerging as an enabling technology for implementing compact, high-performance photonic integrated devices and circuits for signal processing and sensing applications. We provide an overview of our recent work on developing wavelength selective SWG waveguide filters based on Bragg gratings and ring resonators, as well as optical delay lines. These components increase the SWG waveguide component toolbox and can be used to realize more complex photonic integrated circuits with enhanced or new functionality.
基金supported by the State Key Laboratory of Advanced Optical Communication Systems and Networks (Grant No. 2008SH05)
文摘Since novel optoelectronic devices based on the peculiar behaviors of the tunneling probability, e.g., resonant tunneling devices (RTD) and band-pass filter, are steadily proposed, the analytic transfer matrix (ATM) method is extended to study these devices. For several examples, we explore the effect of the scattered subwaves on tunneling; it is shown that the resonant or band-pass structures in tunneling probability are determined by the phase shift results from the scattered subwaves.
