查询词典 signals

a kind of design project of multifunction electric power quality gauged instrument based on virtual instrument is put forward in this article.this system integrates virtual instrument programming and power electronics together,to realize diverse signals of current electric power quality field allin one.the integrated signal generator unit which carries out the collection of high speed digital data,d/ a conversion and analog output in four channels,unsymmetrical synchro control fifo etc.by fpga are introduced,the flow of electric power system various signal which generates by vc programming is elaborated,and the structural design of signal amplification unit is analysed.the experiment text result shows that this gauged instrument has attained current advanced high grade of accuracy and it will accelerate the steps of electric power quality calibration because of its accuracy and versatility.

摘 要：提出一种基于虚拟仪器技术的多功能电能质量标定仪的设计方案，采用虚拟仪器编程技术和电力电子技术相结合实现集目前电能质量领域的多样信号于一体。介绍采用fpga实现高速数字量采集、d/a转换及4通道模拟量输出、非对称同步控制fifo等的集成信号发生单元，阐述利用vc编程实现的电力系统多样信号的产生流程，分析信号放大单元的结构设计。实验测试结果表明该标定仪达到目前先进的高精度等级，由于其准确性和多功能性将加快电能质量标定的步伐。

However, because acetylation and methylation are driven by cell signals, the epigenome is dynamic, enabling it to respond to the environment.

但是，因为乙酰化和甲基化是通过细胞信号驱动的，表观组是动态的，使得它能够对环境进行反应。

The results showed that the method of rubbing the kerf then injection of retrovirus suspension into pancreas could more effectively mark the pancreatic cells than the caudal vein injection and the intraperitoneal injection did in vivo. Furthermore, this study also found that some acinus cells could accept injury stimulus signals to regenerate through resuming mitosis after pancreatic injury.

结果发现在活体条件下，与尾静脉注射及腹腔注射法相比，胰腺伤口涂抹并胰腺内注射反转录病毒的方法能够更有效的标记胰腺细胞；而且，通过对标记细胞的世系追踪研究证明，在胰腺损伤后，胰腺腺泡细胞能够接受损伤信号刺激发生再生。

In this thesis, the theory, algorithm and applications combined with the project "research on the feature extraction and analysis of XX acoustic vector" are discussed, according to the present development, main problems and practical needs in application of feature extraction of pressure and acoustic vector signals.

本文根据声压和声矢量信号特征提取的研究现状、存在的主要问题以及工程实际应用的基本要求，结合基金项目"XX声矢量特征提取与分析研究"的内容，对目标特征提取及其分类识别进行了理论、算法与应用方面的探讨。

In order to reduce calculation in the process of vertical scale identification of torpedo acoustic image,we present an improved decoherent multiple signal classification method based on quadrature complex sampling which suits to estimating the vertical highlights of submarine with the characteristics of near distance and coherent signals .

在鱼雷声成像垂直尺度识别中，根据潜艇垂直方向上目标亮点相距较近，且为相干信号源的特点，同时为了减小运算量而易于工程实现，提出了一种基于正交采样的高分辨DOA估计算法，即正交解相干MUSIC算法。

However, little is known about the effect of weak background noise on the detection of acoustical signals in animals.

平时被人们忽视的弱背景噪声是否影响动物的声信号的检测，其神经机制是什么，还未见相关的研究报道。

Input signals can be signal current or voltages originating from corresponding measurement transducers or measurement value acquisition systems.

输入信号可以电流或电压信号，由相应的测量传感器或测量值采集系统的来源。

Pole-placement and Inner model tuning methods are discussed finally;(2) For the linear derivative action, several different tracker-differentiators are presented to improve the quality of the derivative signals;(3) A neural network tuning method is given for the nonlinear PID controller which includes the above tracker-differentiator;(4) For the linear integral action, a nonlinear pre-phase integrator is studied in order to decrease the phase delay problem; Simulation results show that the nonlinear PID controller including the pre-phase integrator posseses better performance in both fast and stable property, and strong ability of anti-disturbance;(5) A simple optimal criteria is introduced to optimize the parameters of the nonlinear PID controller based on the pre-phase integrator.

仿真研究表明，由此形成的非线性复合积分PID控制系统，具有快速而平稳的过渡过程和超强的干扰抑制能力；(5)采用物理意义简单明确的目标函数的优化设计方法，对上述非线性PID控制器进行参数整定，达到了满意控制典型工业过程的目的。通过对直线电机伺服系统的仿真研究，表明该种非线性控制器具有同时跟踪多个目标的优越性能。

By analyzing, the fault transient component of third harmonic voltage at neutral is approximately equal to that at terminal. Choosing their sum and difference as the action and restrai nt signal respectively, the protection detects the ground fault by comparing the spectrum energy of action and restraint signals.

该保护方案根据单相接地故障后机端和中性点 3次谐波电压的故障暂态分量近似相同的特点，把两个故障分量的相量和与相量差分别作为保护动作信号及制动信号，通过比较数据窗内相应信号的谱能量检测定子单相接地故障。

The system is partly a multivariable control system which means that one output action variable (e.g. chemical charge) is controlled from more than one source (e.g. two feed forward signals, one feedback signal and an operator bias input).

该系统是部分的多变量控制系统，就是说一个输出动作变量是由多于一个的源变量(比如两个前馈信号，一个反馈信号和操作员的偏置输入)来控制的。

The split between the two groups can hardly be papered over.

这两个团体间的分歧难以掩饰。

This approach not only encourages a greater number of responses, but minimizes the likelihood of stale groupthink.

这种做法不仅鼓励了更多的反应，而且减少跟风的可能性。