查询词典 frequency analysis

To resist multipath and ISI in acoustical communication, a single filter receiving method and a new method, namely preprocessing frequency hopping filtering method, were adopted simultaneously. A controlled preprocessing frequency hopping filter was added before mixing frequencies of signal receiving system to strengthen resistance against multipath and ISI. The method was simulated respectively on two frequency hopping sequences of PN code and increasing sequence.

除了采用以往的单一滤波接收处理方法，本文还采用了一种新的接收处理方法，即前置跳频滤波接收处理方法，与其他方法不同的是在信号接收系统的混频之前增加了可控的前置跳频滤波器，可以增强抗多途和码间串扰能力，并对此方法分别采用PN码和递增序列2种跳频序列进行仿真研究。

Common induction motor variable frequency system is extensively applied, but common induction motors are designed by constant frequency and constant voltage, when the frequency change that induction motor works, the parameter and performance of common induction motor will change.

摘要普通交流异步电动机变频调速系统被广泛应用，但是，普通交流异步电动机都是按恒频、恒压设计的，在频率改变时，电动机的参数和性能都将发生改变。

For this reason, an optimal automatic timing control algorithm is proposed, that can restrain the switching frequency in a certain range to achieve the purpose of high efficiency and energy conservation. Taking such factors as inductive reactance at AC side, switching frequency, harmonic distortion rate and switching loss as well as the interaction among them into consideration, the formulas for inductive reactance and switching frequency are given; then by use of digital signal processor TMS320F2812, a prototype based on the proposed algorithm is implemented, and using this prototype the effectiveness and practicality of the proposed method are verified by experimental research and simulation.

文章提出了自动定时控制的优化算法，将开关频率限定在一定范围内，以达到高效节能的目的；综合考虑交流侧感抗、开关频率、谐波畸变率和开关损耗等指标，提出了主电路电感参数和开关频率的选择公式，并采用TMS320F2812数字信号处理器构造了试验样机，进行仿真和试验研究，其结果证明了该方法的有效性和实用性。

And infrequency domain it is normally describes by the frequency responsefunction. The frequency response range is always limited, especially isthe main factor of the frequency response of the system.

传感器及测量系统的频响范围总是有限的，特别是传感器的频响范围往往是限制整个系统频响的主要环节。

This kind of architecture, however, accompanies with some radio frequency imperfections such as the direct current offset, frequency offset, inphase/quadrature imbalance, and etc. In this thesis, it focuses on the topic of the RF impairment of frequency dependent I/Q imbalance.

但是，这种架构会一起伴随著一些射频的不完美效应，像是直流电偏移，频率偏移，以及I/Q不平衡效应等等…在这篇论文中，主要是研究频率相依的I/Q不平衡效应。

The frequency divider with an inverting unit and a plurality of switch inverters in series makes the two inphase selectively turned on synchronously and turned off synchronously, thereby the frequency divider, with low phase noise, can tolerate a high frequency clock.

本发明提供的分频器，通过反相单元及串联的多个切换反相器的运作，使每一切换反相器的同相开关可以选择性地同步开启或同步关闭，以使得具有低相位噪声的分频器可处理高频时钟。

Frequency factor is the work of CPU frequency and CPU internal frequency ratio, such as the 3 octave, octave, etc.

倍频系数就是CPU的工作频率和CPU内部频率的比值，如3倍频、5倍频等。

Account to compare with the traditional frequency, the single-chip-machine frequency that join together accounted to simplify with the FPGA the electric circuit knothole designs, increasing the system design of realize sex with dependable, measure the scope of frequency comes to an a software for, realizes arithmetic figure system hardware turns, this is the new trend that arithmetic figure logic design.

和传统的频率计相比，单片机和FPGA结合的频率计简化了电路板的设计，提高了系统设计的实现性和可靠性，测频范围达到了100MHz，实现了数字系统硬件的软件化，这是数字逻辑设计的新趋势。

Using two channel tree-structured filter banks, an image can be decomposed into a pyramid structure, with various band information: such as low-low frequency band, low-high frequency band, high-high frequency band etc.

小波分析是一种时间-尺度分析方法，可被看作傅立叶变换之后又一里程碑式的发展，是近年来迅速发展起来的新兴学科，小波变换应用于图像处理的基本思想就是把图像进行多尺度、空间-频率分解。

Where the irrigating frequency was 1 or more than 1 every four days, it did not remarkably affect the ET of potato; but where the irrigating frequency was 1 every six days or 1 every eight days, the ET of potato measured by a lysimeter was obviously higher than what it was in the treatment with a higher irrigating frequency.

大于或等于1次/4 d滴灌灌水频率对马铃薯的腾发量影响不明显；但当滴灌灌水频率为1次/6 d或1次/8 d时，由蒸渗仪测得的马铃薯腾发量明显低于更高频率处理。

Molecular Distillation is a kind of high vacuum distillation method, which is suitable for the separation of high boiling, heat sensitivity and viscidity products.

分子蒸馏技术是一种在高真空条件下进行的连续蒸馏过程，适合于分离高沸点、热敏性及具有生物活性的混合物。

They are to the Noughties what yuppies were to the Eighties .

那在六十年代是时髦的，但在八十年代肯定是过时了