查询词典 frequency analysis

In order to eliminate intercarrier interference of orthogonal frequency-division multiplexing communication systems, based on interference coefficients analysis and reasonable estimation, a novel decorrelation interference cancellation scheme using frequency-domain equalization was proposed.

为消除正交频分复用系统中的载波间干扰，在对干扰系数分析与合理估计的基础上，提出了一种基于频域均衡思想的解相关干扰抑制方案。

The Hilbert amplitude envelope of the stator current includes the low frequency of fault characteristic, thus it can reduce the signal length by resample the Hilbert amplitude envelope of the stator current by downsampling, which can avoid spectrum aliasing. Then it can reduce the computation time of the MUSIC Method for the spectrum analysis to the resampled signals for the given bandwidth. Meanwhile combining continuous subdivision Fourier transform and rotor slot harmonics based slip estimation it can in advance estimate the concrete values of the fault characteristic frequency, and then inquiry purposely the fault feature component information in the stator current spectrum in order to accomplish the broken rotor bar fault with high sensitivity and h reliability, which eliminates adverse effect of issuable false peaks to the fault detection and formed a novel scheme to detect broken rotor bar fault.

定子电流Hilbert幅值包络信号包含了低频的故障特征频率调制信号，故通过对定子电流Hilbert幅值包络信号进行降采样率重采样、减少分析信号长度，可避免低频段频谱混叠，再对减少的重采样数据进行具有超分辨率的MUSIC低频段估计，可大大降低MUSIC算法频谱估计时间；运用连续细化傅里叶变换和转子齿槽谐波转差率估计技术，可预知故障特征频率精确值，从而可有目的地查询故障分量，消除MUSIC虚假波峰对故障检测混淆的影响，大大提高了故障检测的灵敏度和可靠性，以此形成异步电动机转子断条故障检测新方法。

The high frequency combustion instability in liquid rocket engine LRE is analyti cally studied by usin g CFD methods.The comprehensive model and governing equations for numerical simu lation of high frequency combustion instability are presented.The PISO and MacCo rmack algorithms are compared in this study.Both methods can successfully handle combustion instability analysis.

应用CFD方法对液体火箭发动机中的高频燃烧不稳定性进行了分析研究，建立了液体火箭发动机不稳定燃烧数值模拟的综合模型和控制方程，比较了PISO和Ma cCormack两种算法，得出了两种算法均能成功应用于不稳定燃烧分析的结论。

Up to now, the performance analysis of noncoherent space-frequency coding whose receiver does not know the channel state information and the methods to reduce the encoding-decoding complexity have not been solved, and this has constituted a bottleneck of the research of noncoherent space-frequency coding.

非相干空频码具有接收端不需要知道信道信息的特点，而到目前为止，针对非相干空频码的性能分析和如何降低编译码复杂度的问题还没有得到很好的解决，这些问题已成为研究非相干空频码的瓶颈。

By using the Ricker wavelet and thin inter-beds model data, taking Morlet wavelet, MSW wavelet (A mother wavelet which can match seismic wavelet) and three-parameters wavelet as mother wavelet respectively, the calculated instantaneous frequency is analyzed. Results show that the instantaneous frequency analysis based on three-parameter wavelet has good anti-noise ability and higher temporal resolution.

利用Ricker子波和薄互层模型数据，分析了以Morlet小波、匹配地震子波的小波及三参数小波为基本小波计算的瞬时频率，结果表明：基于三参数小波的瞬时频率分析方法具有良好的抗噪性能及较高的时间分辨率。

Aimed at Wigner-Ville transformation crossterms badly interfering signals' resolution in the time-frequency analysis, the improved smoothed Wigner-Ville transformation is employed to analyze the time-|frequency characteristics of the Ricker wavelet synthesis record.

针对 Wigner-Ville变换中交叉项对信号时频分析的分辨率有较大的干扰，采用改进了的平滑Wigner-Ville变换处理技术，来分析雷克子波合成记录的时频特征，能够提高时频分析在时间和频率上的分辨率。

A correction method for beam hardening, involving simple operations of the original polychrornatic projection sinogram, was presented based on the analysis of three physics properties implied by beam hardening. Its correction principle was deduced mathematically. A noise reduction method was proposed to suppress the noise enlarged by the harden correction by processing the high-frequency and the low-frequency components in the projection sinogram respectively.

在分析射束硬化现象具有的3个物理属性基础上，提出了一种对原始多色投影正弦图进行操作的硬化校正方法，并从数学上证明了其校正原理，针对该方法带来的噪声放大问题，研究了一种基于高、低频信息分类处理的噪声抑制方法。

The essence of EDID is to set up a normal behavior fuzzy sub collection A on the basis of watching the normal system transfer of the privilege process, and set up a fuzzy sub collection B with real time transfer array, then detect with the principle of minimum distance in fuzzy discernmethodThe innovation point of this paper is : Put forward the method of EDID, can not only reduce efficiently false positive rate and false negative rate, also make real time intrusion detection to become possibility; have independent and complete character database, according to the classification of monitoring program, design normal behavior and anomaly behavior etc., have raised the strongness of IDS; Use tree type structure to preservation the character database, have saved greatly stock space; in detection invade , carry out frequency prior principle, prior analysis and handling the behavior feature of high frequency in information table, have raised efficiency and the speed of detection, make real time intrusion detection to become possibility; have at the same time realized anomaly intrusion detection and misuse intrusion detection, have remedied deficiency of unitary detection method.

本文的创新点是：通过对特权进程的系统调用及参数序列的研究，提出了基于Euclidean距离的入侵检测方法EDID，不仅能有效降低漏报率和误报率，而且使实时入侵检测成为可能；设计有独立而完整的特征数据库，根据被监控程序的类别，分别设计正常行为、异常行为等，提高了检测系统的强健性和可伸缩性；特征数据库按树型结构存储，大大节省了存储空间；在检测入侵时，实行频度优先原则，优先分析和处理信息表中的高频度行为特征，提高检测的速度和效率，使实时入侵检测成为可能；同时实现了异常入侵检测和误用入侵检测，弥补了单一检测方法的不足。

Two-channel frequency-domain analysis is used to find the fundamental frequency of unvoiced speech signals, and then to control the stimulation rate of current pulses.

基于传统的汉语语音声调提取方法，采用双通道的频域分析法进行基音分析，提取汉语语音声调的变化轨迹，控制刺激模式的产生。

Convolved audio signals can be separated by frequency-domain blind source separation. Complex independent component analysis is performed in each frequency bin of the mixed signal, but the permutation inconsistency and scaling arbitrary are involved.

混合语音信号可以使用盲分离频域解法，对观测信号在每一个频点分别进行复值独立分量分析算法来解混并得到分离信号，但带来了幅值和次序不定问题。

He got into race cars, while my father liked go-karts more, so I didn't really pay attention to what Diego was doing, as I was just racing karts.

叔叔开的是跑车，而我父亲更喜欢越野卡丁车，所以我并不太关注Diego在做什么，我仅仅在跑我的卡丁车而已。

She is at present gone to look for the best nectar and ambrosia to regale me this evening.

她今晚为款待我，现在又去准备美酒佳肴去了。