| 1. | The main purpose is to discuss the stationarity of two classes of nonstationary processes after wavelet transformations
摘要主要讨论了两类非平稳过程小波?换后的平稳性。 |
| 2. | So pulse blood oxygen signal and various of interaction noise are analysed , the former have character of strong periodic and can be treated as stable procedure with time correlation
脉搏血氧信号具有很强的周期性,在一段时间内可看成是平稳过程,时间上先后相关。 |
| 3. | The relationship of the spca , pca and kpca are established . according to the covariance stationary processes , spca arithmetic also has certain stability and convergent similar to pca arithmetic
由协方差平稳过程，得到谱主成分分析算法也有类似于主成分分析算法的稳定性和收敛性。 |
| 4. | In this paper , we have systematically investigated the relations for strictly stationary processes , wide stationary processes , martingales ang markov processes , many interesting results of interest are obtained
摘要系统研究了严平稳过程，宽平稳过程与鞅及马氏过程的相互关系，得到许多有趣的结果。 |
| 5. | In this thesis , based on principal component analysis ( pca ) , covariance stationary processes and spectral analysis theory of linear operator , spectral principal component analysis ( spca ) is put forward
在主成分分析的基础上，基于协方差平稳过程理论和线性算子谱分析理论，本文提出了谱主成分分析。 |
| 6. | In the cyclic spectrum detection , the ds - ss / bpsk signal is modeled as cyclostationary signal . by searching the peaks on the slice of ds - ss / bpsk signals cyclic spectrum , the carrier frequency can be estimated
周期谱检测方法将ds - ss / bpsk信号建模为周期平稳过程，通过对ds - ss / bpsk信号周期谱的切片进行谱峰搜索，可检测出信号频率。 |
| 7. | The results hold in stationary carr model , carr model with a unit root and other nonstationary processes which satisfy certain conditions and provide a theoretical basis for statistical inference
所得到的结论适用于已得到应用的平稳条件自回归极差模型，也适用于包含单位根的模型和满足条件的其他类型的非平稳过程，为模型的统计推断提供了理论基础。 |
| 8. | Owing to the fact that the wavelet transformation possesses localization and implicit difference property , the suthors show that after wavelet tansformation , the fractionally differenced process and the harmonizable periodically correlated process may be changed into stationary processes
利用小波的局部性及暗含的差分性质，证明了在小波变换后，分数差分平稳过程和可调和周期相关过程是平稳的。 |
| 9. | Applying ftp transformation may acquire adequate precision for dealing with steady variable signal in fault diagnosis of woodworking machine tool field . but ftp transformation ca n ' t completely reflect time change characteristic of signal in unsteady process
在木工机床的故障检测与诊断领域中对于平稳随机信号的处理，采用傅立叶变换可以具有足够的精度，但傅立叶变换难以全面反映非平稳过程的时变特性信号。 |
| 10. | In light of the limitation of fast fourier transform ( fft ) for the method of traditional spectrum analysis to analyze the unsteady signal , wavelet and wavelet analysis are made for the typical unsteady process signal of starting up and shut down with the good characteristic of simultaneous localization in both the time and the frequency domains based on the field test on the vibration of two - row placed units in lijiaxia hydropower station , in which the signal is decomposed into different frequency band , and then the weak signal is caught and the dominant frequency is picked up for the analysis of the vibration source
摘要基于李家峡水电站双排机组振动的现场试验研究，并且针对传统频谱分析方法傅立叶变换( fft )对于非平稳信号已力不从心这一缺陷，利用小波分析方法在时域和频域上同时具有良好的局部化性质，通过对开停机这一典型非平稳过程信号进行小波及小波包分析，将其分解到不同频带内，获取微弱信息和提取优势频率，并对其作振源分析，得出开停机初始时刻因水流不稳均出现强烈的振动现象，且低频段信号能量最大，开停机过程水流脉动压力和尾水涡带摆动是引起定子基础振动的主要原因。 |
