We designed the window function of the optimal Gabor transform based on the time-frequency rotation property of the fractional Fourier transform. Thus, we obtained the adaptive optimal Gabor transform in the fractiona...We designed the window function of the optimal Gabor transform based on the time-frequency rotation property of the fractional Fourier transform. Thus, we obtained the adaptive optimal Gabor transform in the fractional domain and improved the time-frequency concentration of the Gabor transform. The algorithm first searches for the optimal rotation factor, then performs the p-th FrFT of the signal and, finally, performs time and frequency analysis of the FrFT result. Finally, the algorithm rotates the plane in the fractional domain back to the normal time-frequency plane. This promotes the application of FrFT in the field of high-resolution reservoir prediction. Additionally, we proposed an adaptive search method for the optimal rotation factor using the Parseval principle in the fractional domain, which simplifies the algorithm. We carried out spectrum decomposition of the seismic signal, which showed that the instantaneous frequency slices obtained by the proposed algorithm are superior to the ones obtained by the traditional Gabor transform. The adaptive time frequency analysis is of great significance to seismic signal processing.展开更多
随着数据业务的爆炸式增长,如何在光网络中有效地利用宝贵的带宽资源已经成为研究人员所关注的焦点。基于时间分配带宽业务(SBS)是自动交换光网络(ASON)中的一种新型业务,可以被认为是传统的按需分配带宽(Bandwidth on De-mand,BoD)业...随着数据业务的爆炸式增长,如何在光网络中有效地利用宝贵的带宽资源已经成为研究人员所关注的焦点。基于时间分配带宽业务(SBS)是自动交换光网络(ASON)中的一种新型业务,可以被认为是传统的按需分配带宽(Bandwidth on De-mand,BoD)业务的一种具体实现,SBS的出现既可以有效地为运营商节省宝贵的带宽资源,又可以降低用户的成本开销。文章从管理模型、实现方法以及社会价值等几个方面对SBS进行了详细的描述。展开更多
O43 98010691水平大气中横向风对自适应光学系统性能的影响=Influence of transverse wind on performanceof an adaptive optics system in horizontal atmosphere[刊,中]/张德良,姜文汉,吴旭斌(中科院光电技术研究所.四川,成都(610209...O43 98010691水平大气中横向风对自适应光学系统性能的影响=Influence of transverse wind on performanceof an adaptive optics system in horizontal atmosphere[刊,中]/张德良,姜文汉,吴旭斌(中科院光电技术研究所.四川,成都(610209)),严海星,李树山(中科院力学研究所.北京(100080))//光学学报.—1997,17(5).—614—620从理论上分析了光波在水平大气中传播时传播路径上的横向风对理想补偿系统和时间带宽有限的自适应光学系统性能的影响,得到了自适应光学系统的Strehl比与横向风速之间关系的解析表达式,并据此得到了一批计算结果。图6参3(严寒)展开更多
基金supported by national natural science foundation of China(No.41274127,41301460,40874066,and 40839905)
文摘We designed the window function of the optimal Gabor transform based on the time-frequency rotation property of the fractional Fourier transform. Thus, we obtained the adaptive optimal Gabor transform in the fractional domain and improved the time-frequency concentration of the Gabor transform. The algorithm first searches for the optimal rotation factor, then performs the p-th FrFT of the signal and, finally, performs time and frequency analysis of the FrFT result. Finally, the algorithm rotates the plane in the fractional domain back to the normal time-frequency plane. This promotes the application of FrFT in the field of high-resolution reservoir prediction. Additionally, we proposed an adaptive search method for the optimal rotation factor using the Parseval principle in the fractional domain, which simplifies the algorithm. We carried out spectrum decomposition of the seismic signal, which showed that the instantaneous frequency slices obtained by the proposed algorithm are superior to the ones obtained by the traditional Gabor transform. The adaptive time frequency analysis is of great significance to seismic signal processing.
文摘随着数据业务的爆炸式增长,如何在光网络中有效地利用宝贵的带宽资源已经成为研究人员所关注的焦点。基于时间分配带宽业务(SBS)是自动交换光网络(ASON)中的一种新型业务,可以被认为是传统的按需分配带宽(Bandwidth on De-mand,BoD)业务的一种具体实现,SBS的出现既可以有效地为运营商节省宝贵的带宽资源,又可以降低用户的成本开销。文章从管理模型、实现方法以及社会价值等几个方面对SBS进行了详细的描述。
文摘O43 98010691水平大气中横向风对自适应光学系统性能的影响=Influence of transverse wind on performanceof an adaptive optics system in horizontal atmosphere[刊,中]/张德良,姜文汉,吴旭斌(中科院光电技术研究所.四川,成都(610209)),严海星,李树山(中科院力学研究所.北京(100080))//光学学报.—1997,17(5).—614—620从理论上分析了光波在水平大气中传播时传播路径上的横向风对理想补偿系统和时间带宽有限的自适应光学系统性能的影响,得到了自适应光学系统的Strehl比与横向风速之间关系的解析表达式,并据此得到了一批计算结果。图6参3(严寒)
