查询词典 frequency function

The main job and contribution of this paper are as follows:Based on narrowband signal processing, we propose a new method for FH signal blind detection and blind parameter estimation. Firstly, compute the cross-correlation function of FH signals from multichannels, then we get the cross power spectral density matrixCSDM Secondly, select the hops of FH signals from the CSDM via processing and analyzing the CSDM, meanwhile reduce the influence coming from noise, fixed frequency signal and other interferences; Lastly, estimating the DOA of every hop and according to the DOA, we can separate the hops, get the number of FH signals and their parameters. Propose a new method for designing the threshold in FH signal detection. This method makes it easy to get the threshold by theoretic computing and it can extremely reduce the interference of non-FH signals.Based on broadband signal processing, we propose a new method for FH signal blind detection and blind parameter estimation. Firstly, get the DOA of the signals by wideband spatial spectrum estimation; secondly, separate the signals by spatial filtering using wideband beamformer; Lastly, we propose two methods for FH signal blind detection and blind parameter estimation, one is for several constant hop-rate FH signals whose dwell-time are different and another is for a single FH signal whose hop-rate is alterable.By employing spatial interpolation in broadband signal beamforming, it can reduce the number of antenna elements and corresponding RF modules, A/D converters, etc. It can also eliminate the mutual coupling between antenna elements while getting the narrower main beamwidth and lower sidelobe level.

本文的主要研究工作和贡献如下：●提出了一种基于窄带处理的FH信号盲检测和参数盲估计的实现方法，即首先求出多路信号之间的互相关，进而得到互功率谱密度矩阵，然后通过对CSDM进行对折处理来抑制噪声、定频信号及其他干扰的影响，并将所有属于FH信号的hop(每一跳的驻留时间在时频图上持续的线段)从CSDM中筛选出来，最后用阵列信号处理中的到达方向估计理论在频域中估计出各个hop的方向参数，利用方位信息完成FH信号分离并得到FH信号的数目及其各自的参数集；●提出了一种确定FH信号检测门限的策略，该策略不仅使得检测门限能够通过理论计算得到，而且还显著地抑制了非跳频信号的干扰，从而能有效地检测出FH信号；●提出了一种基于宽带处理的短波FH信号盲检测和参数盲估计的实现方法，即首先利用宽带空间谱测向技术得到接收信号的DOA，然后采用宽带波束形成技术对特定方向进行空间滤波，实现多个信号的分离，最后分别提出了两种FH信号的盲检测和参数盲估计方法，第一种方法适用于空间某个特定方向上存在着几个驻留时间不同的恒跳速FH信号和其他干扰信号的混合信号，第二种方法适用于空间某个特定方向上仅含一个可变跳速的FH信号和噪声的混合信号；●将空间插值的概念和宽带波束形成技术结合起来，提出了一种基于频域处理的宽带恒定束宽的波束形成方法。

In order to solve these problems encountered in the application of Artificial Intelligence in fault diagnosis of power transformer, some improved methods are presented, the main research work of this dissertation consists of the following parts: The conception of cumulative frequency in data reliability analysis is utilized to unify the results of Dissolved Gas Analysis. And with the application of the class-attribute function, the evaluation of typicality of samples and the selection of characteristic vectors of fault could be realized by integrating the technique of multivariate statistical analysis.

针对目前应用人工智能技术进行变压器绝缘故障诊断时所遇到的主要困难，本文进行了深入的研究与分析，进而提出了相应的解决方法，主要的研究工作如下：提出利用可靠性数据分析中累积频率的概念对油中溶解气体分析数据进行归一化处理；并在引入"类属函数"的概念后，结合多元统计分析技术实现了样本的典型性评价与故障特征矢量的选取。

Cymometer as a measuring apparatus, often called electronic counter, and its basic function is to measure the frequency and signal cycle.

频率计作为测量仪器的一种，常称为电子计数器，它的基本功能是测量信号的频率和周期。

The standard function mode is that the system's excitation functions are sine wave, square wave and curve of free little damped vibration, the vibration's frequency are about 2Hz. The vibration mode must be in accord with the crane's work status in the vision computer.

调查表明，集装箱桥机驾驶员座椅工作中更多的是小车运行方向的前后振动，所以我们的多自由度座椅振动平台采用X方向的单自由度激励，即可实现座椅振动的大部分体感功能，同时开发成本也大大降低。

Applying energy variation principle, we give equation s defining parameters in flexural function, stability equation , frequency equation , and general formulae of minimum critical force and minimum eigenfrequency as well.

应用能量变分原理，给出了确定挠曲函数中待定参数的方程，以及稳定性方程和频率方程，给出了求最小临界力和最小固有频率的一般公式。

The correlation method is the one that computes the frequency response of the components of DEH by utilizing the input and output data, and then calculates the transfer function of the DEH system by using Levy method.

相关辨识法是利用输入与输出数据的自相关和互相关函数求取系统频率特性，进而拟合出其传递函数的方法。

The result showed: The capsule can obviously decrease the vomiting times and delay the vomiting delitescence (P.05, P.01). It can also increase the frequency and range of the rabbits' gastrointestinal motility and improve the big rats' stomach empty rate (P.05, P.01). The capsule has strong and wide the function of restraining bacteria.

结果表明该药可明显减少左旋多巴所致狗和硫酸铜所致家鸽呕吐次数，延长呕吐潜伏期（P.05，P.01）；可使家兔在体胃运动频率明显增加，胃运动幅度明显增高（P.05，P.01）；可使大鼠胃排空率明显提高（P.05，P.01），并且具有广泛和很强的抗菌作用。

This method is founded on the frequency domain model of DS-UWB array signals. The spatial spectral function is then derived for analysis.

该方法建立在直接序列超宽带系统阵列信号的频域模型。

The company has manufactured some products with the function of attemperation and diathermancy, which improving the therapeutic effect, so making you use more comfortable, and this is a huge advancement in the conception of Medium-Frequency Electrotherapy.

本公司推出的具有调温透热功能的产品，不仅提高了治疗效果，也使患者在治疗过程中感觉更加舒适、更加人性化，这在中频仪器理疗的理念上是一次飞跃。

If you are using the perlin noise function to render an image to the screen, there will come a point when an octave has too high a frequency to be displayable.

如果你正使用柏林噪声函数在屏幕上渲染图象的话，如果倍频频率太高将会使缩成一个点以至于不能显示，这就是因为你屏幕的分辨率不够。

It has been put forward that there exists single Ball point and double Ball points on the symmetrical connecting-rod curves of equilateral mechanisms.

从鲍尔点的形成原理出发，分析对称连杆曲线上鲍尔点的产生条件，提出等边机构的对称连杆曲线上有单鲍尔点和双鲍尔点。

The factory affiliated to the Group primarily manufactures multiple-purpose pincers, baking kits, knives, scissors, kitchenware, gardening tools and beauty care kits as well as other hardware tools, the annual production value of which reaches US$ 30 million dollars.

集团所属工厂主要生产多用钳、烤具、刀具、剪刀、厨具、花园工具、美容套等五金产品，年生产总值3000万美元，产品价廉物美、选料上乘、质量保证，深受国内外客户的青睐