共查询到19条相似文献,搜索用时 328 毫秒
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在许多声信号处理系统中,常常需要在一实序列的相邻两个样值之间进行快速离散内插.本文提出了一种基于FHT的离散信号快速内插算法.该算法所需的实乘次数只有Hsu-Lin算法实乘次数的60%左右,而实加次数还不到Hsu-Lin算法的60%.此外,它允许内插率L可为任意整数,且适用于并行处理.本文算法已用软件实现,对实际声信号处理行之有效. 相似文献
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基于声程差的多通道广义相关时延估计及其DSP实现 总被引:3,自引:0,他引:3
本文将基于声程差的广义相关法时延估计应用于六基元阵,同时成功地将中值滤波及可变门限算法用于相关峰的自动跟踪,为了提高精度,导出了新的内插公式。最后给出了时延估计的结果。 相似文献
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荧光检测和分析技术中,荧光寿命的精确测量具有重要意义。针对纳秒级荧光寿命在流式细胞分析系统中无法直接测量的问题,提出一种基于互相关算法的脉冲时延估计荧光寿命表征方法。该方法将改进的线性调频Z变换算法与相关峰内插算法相结合,并与标准FFT算法仿真做对比,通过对哺乳动物细胞的荧光寿命进行测量,将所得数据进行处理,验证线性调频Z变换(MCZT)和相关峰内插(FICP)算法性能。实验结果表明,使用该算法降低了FFT计算带来的栅栏效应,可以提高互相关函数的分辨能力,测量荧光寿命的相对误差提高了4.344 3%。 相似文献
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用SQRID直流磁强研究了La1.85Cr0.15Cu1-xFexO4-y(x=0.0,0.002,0.004和0.006)多晶样品在不同磁场下(H=0.01,0.03,0.05T)正常态的直流磁化率与温度关系和超导转变温的关系呈宽峰行为。随着Fe掺杂的增多,直流磁化率与温度的关系由宽峰行为迅速转变为Curie-Wiss行为。与此同时,超导转变温度也由不掺Fe的31.0K增加到33.6K(x=0. 相似文献
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在Coulomb-Born近似下,利用满足一定边界条件且包括电子动量相关的库仑波近似描述e-+He(1s2)→He+(1s1)+2e-两出射电子,得出了三重微分散射截面(TDCS)的明晰表达式,计算了入射能为600eV和400eV、散射角为4°和10°条件下的TDCS,并与实验值和Brauner理论结果进行了比较。结果发现,电子动量相关效应对解释binary峰和recoil峰的大小和位置起重要作用。 相似文献
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以空间频谱描述图像结构,以图像灰度起伏的方均根值与噪声方均根值之比表示信噪比,系统分析了目标图像结构和噪声对相关哈特曼-夏克波前传感精度的影响。理论分析表明,两个子图像的相关函数峰值位置的亚像元插值误差等于其各离散频率成分的相关函数峰值位置插值误差的加权平均;相同功率下,低频成分的加权系数较小,高频成分的加权系数与亚像元偏移量有关。一维窄带图像的统计仿真表明,无噪声时,低频成分和接近奈奎斯特频率成分的误差较大,中频成分的误差较小;有噪声时,噪声对高频成分的影响低于低频成分。对典型频谱的32×32图像仿真表明,图像起伏信噪比为2∶1时,子图像平移量计算误差约0.03~0.11像元,与无噪声时相比增加不大。 相似文献
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We demonstrate by a large set of merger simulations for symmetric binary neutron stars (NSs) that there is a tight correlation between the frequency peak of the postmerger gravitational-wave (GW) emission and the physical properties of the nuclear equation of state (EoS), e.g., expressed by the radius of the maximum-mass Tolman-Oppenheimer-Volkhoff configuration. Therefore, a single measurement of the peak frequency of the postmerger GW signal will constrain the NS EoS significantly. For optimistic merger-rate estimates a corresponding detection with Advanced LIGO is expected to happen within an operation time of roughly a year. 相似文献
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Hartl I Schibli TR Marcinkevicius A Yost DC Hudson DD Fermann ME Ye J 《Optics letters》2007,32(19):2870-2872
We report on a passive cavity-enhanced Yb-fiber laser frequency comb generating 230 MW of peak power (3 kW of average power) at a 136 MHz pulse repetition rate. The intracativy peak intensity of 3 x 10(14) W/cm2 for the 95 fs pulse is sufficient to ionize noble gases, such as Xe, Kr, or Ar. The laser system is based on a mode-locked Yb-fiber similariton oscillator in conjunction with a cladding-pumped chirped-pulse fiber amplifier. After recompression, 75 fs duration pulses at a 13.1 W average power are obtained. These pulses are then coherently added inside a passive ring cavity by controlling the fiber oscillator's pulse repetition rate and carrier-envelope offset frequency. This system is well suited for studying high-field phenomena at very high pulse repetition rates. 相似文献
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We have performed X ray diffraction experiments on LixTiS2 and have found an experimental correlation between features observed in the (00?) peak width and -δx/δV data. (00?) peak broadening is indicative of imperfect order in the c direction of the lattice. This suggests that three dimensional models for lithium intercalation in TiS2 should be investigated. 相似文献
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Leonid I. Muravsky Olexander M. Sakharuk Liliana Byczkowska-Lipińska 《Optics and Lasers in Engineering》2009,47(6):712-720
An optical speckle-displacement correlator based on hybrid optical–digital joint transform correlator architecture with a digital first stage and an optical second stage has been used to determine the correlation peak position with subpixel accuracy, without the use of intricate interpolation algorithms. A thorough analysis and a calculation of the parameters of the second optical stage are performed in order to achieve the necessary magnification of the correlation peak, so as to obtain an accurate definition of the peak position. The experiment setup for the realization of the optical speckle-displacement technique was constructed with a digital Fourier processor as its basic component, making possible a joint power spectrum median and ring median binarization, and an optical Fourier processor. The results which were obtained demonstrate that a setup of this kind can produce sharp and narrow correlation peaks, and can provide the necessary magnification for finding the peak position with subpixel accuracy. 相似文献
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色氨酸的非线性分频荧光研究 总被引:3,自引:0,他引:3
色氨酸 (Trp)在 350nm处产生一个荧光峰 ,在 70 0nm处产生一个 (分频 )荧光峰 ,此两峰荧光强度F3 50nm 和F70 0nm 均与Trp浓度 ( 0~ 1× 10 -5mol·L-1 )成线性关系 ,随着Trp浓度增大 ,350和 70 0nm半峰宽(Δλ) 3 50 ,(Δλ) 70 0 缓慢减小 ,而F70 0nm/F3 50nm 值和半峰宽比 (Δλ) 70 0 /(Δλ) 3 50 为一常数 ,此两峰具有相似的荧光特性。根据建立的分频荧光能级原理和非线性共振分频荧光原理探讨了色氨酸分频荧光峰产生的原因 相似文献
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We used the time correlation of shadowgraph images to determine the angle Theta of the horizontal component of the plume velocity above (below) the center of the bottom (top) plate of a cylindrical Rayleigh-Bénard cell of aspect ratio Gamma identical with D/L=1 (D is the diameter and L approximately 87 mm is the height) in the Rayleigh-number range 7 x 10(7)=R=3 x 10(9) for a Prandtl number sigma=6. We expect that Theta gives the direction of the large-scale circulation. It oscillates time periodically. Near the top and bottom plates Theta(t) has the same frequency but is anticorrelated. 相似文献