查询词典 spectrum analysis

To solve the problem that the-spectrum estimation performance based on covariation under the-stable noise environmentbecomes obviously worse when the distribution parameter is small,a method of fractional low-order covariance spectrum estimation was proposed.

针对在分布参数值较小时稳定分布噪声下基于共变的谱估计性能较差这一问题，提出了一种分数低阶协方差谱估计方法。

School of Electronic and Information Engineering,Dalian University of Technology,Dalian,Liaoning 116024,ChinaStable processes can better model the impulsive random signals and noises in physical observation.This paper briefly describes its spectral representation,proposes a new different spectral density from power spectrum density of second order processes,thus can get a new concept of stable white noise based on covariation spectrum,and a method of identification of nonlinear PAR system based on least p-norm.

描述了稳定分布的谱表示，提出了共变谱密度的概念，得到一种基于自共变序列与共变谱的稳定分布白噪声与有色噪声的概念及其判断标准，对传统意义上的白噪声进行了广义化，依据多项式自回归系统模型，对基于稳定白噪声输入的系统输出非线性稳定有色噪声建立其非线性PAR模型，提出基于最小P范数的EIRLP算法对非线性PAR系统进行辨识。

A necessary and sufficient condition for a fx + t(y + g to be a bent function is disscussed,on which basis a necessary and sufficient condition for a function F = fix + tq + g to be a bent function is given when q is not a balanced-function by use of cyclic walsh spectrum and decomposition formula of walsh spectrum.

讨论了形如fx+τ(y+g的布尔函数是Bent函数的充分必要条件，在此基础上利用Bent函数的循环Walsh谱及谱分解式，进一步给出了当q不是平衡函数时，形如F=fx+τ(yq+g布尔函数是Bent函数的充分必要条件。

Simulation results show that:1 The FWHM of the spectrum has an effect on the performance of a depolarizer. 2 The spectrum width of every longitudinal mode has no effect on the performance.

仿真计算表明：1消偏器的性能与光谱的半峰全宽有关；2每个纵模谱宽的变化不影响消偏性能。

The data were applied to simulate the neutron energy spectrum and angular distribution of Lanzhou University 3×10^12 s^(-1) intense neutron generator with 260 keV deuteron beam using MCNP. The interactions of neutron and the materials of neutron generator and laboratary wall were included in this MCNP simulation. The simulation results on the neutron energy spectrum and angular distribution of Lanzhou University 3×10^12 s^(-1) intense neutron generator with 260 keV deuteron beam were presented.

以分割法计算得到的能谱和角分布数据为基础，建立了D-T中子源Monte-Carlo模拟抽样模型，在考虑中子发生器各元件材料及实验大厅墙壁对快中子的慢化、散射和吸收的条件下，采用MCNP程序对兰州大学3×10^12s^(-1)强流中子发生器260 keV氘束流能量下的中子能谱和角分布进行了模拟，给出了模拟结果。

Furthermore, the interaction of L-C10HL and D-C10HL with cyclodextrin was also investigated by fluorescence excitation spectrum and circular dichroism spectrum.

利用荧光激发光谱和圆二色性谱研究了L-C10HL和D-C10HL与环糊精之间的相互作用。

Based on the table of matrix element of spectrum decomposition, the Helmhotz matrix can be decomposed by recursion of the direct solution. A numerical comparison has been made with the spectrum LU decomposition and direct solution.

通过与谱法分解和直解法在分解精度和分解速度两方面的比较表明，本文方法与谱法相比，在非均匀介质中亥姆霍兹算子矩阵分解时的精度提高10倍；在计算速度方面，混合方法比简化后的直解法快。

The continuous channel model is represented by the delay power spectrum and the discrete channel model by the envelope delay power spectrum and the arrival rate of the paths.

连续的频道模型被延迟力量光谱和不连续的频道表现模型被路径的信封延迟力量光谱和抵达率。

By means of the discrete frequency spectrum, the frequency spectrum leakage s of the conventional DFT and the DFT with a Hanning window are comparatively analyzed in this paper.

利用离散频谱详细对比分析了DFT的频谱泄漏和加汉宁窗DFT的频谱泄漏现象，讨论了用异步顺序采样值计算电量产生误差的原因，提出了利用异步顺序采样值精确计算电量的方法，实现了畸变电量的精确测量。

At first the frequency spectrum of diffraction light is sampled so as to make holographic grating diffraction discrete in space frequency, namely, in the grating code is included discrete frequency spectrum, which satisfies requirements of human vision.

首先对衍射光的频谱进行采样，使全息光栅衍射的是空间频率不连续的离散光，即在光栅的编码中只包含离散光频谱，且满足人眼视觉要求。

So it was last week in Selma , alabama.

上星期在亚拉巴马州塞尔马市发生的事件也是这样一个转折点。

The group also spearheads various social programs in China.

该组织还带头参与中国的各种社会活动。