查询词典 instantaneous

This dissertation studies several kinds of instantaneous frequency estimation methods, pay much attention to the performance of instantaneous frequency estimation algorithm based on the peak of time-frequency distribution. It gives the theory and algorithm of polynomial Wigner-Ville distribution, analyzes its performance to the noise of the moving target in the air.

对常用的几种瞬时频率估计算法进行了研究，重点研究了基于时频分布峰值的瞬时频率估计算法的性能，给出了多项式Wigner-Ville分布的原理与算法，分析了在直升机定位这种特定情况下的有效性。

It gives performance comparison of instantaneous frequency estimation algorithms based on the peak of Wigner-Ville distribution and fourth-order polynomial Wiger-Ville distribution, analyzes the influence of window width to the estimation performance of instantaneous frequency estimation algorithms based on time-frequency distribution.

在不同飞行状态下，给出了基于Wigner-Ville分布、四阶多项式Wigner-Ville分布峰值的瞬时频率估计算法的性能对比，并分析了窗长对瞬时频率估计性能的影响。

An instantaneous optimal semi-active control method is put forward. Combined sliding mode control with lyapunov's stability theory, the control weights matrix, which can minimize structural instantaneous energy, is designed. Simulation and shaking table test is conducted to validated the method's effectiveness. To solve combination explosion of controlled structural state encountered in high-rise building control, the semi-active control strategy, which can drive structural state point to reach the sliding mode switching band, is designed by using sliding mode control theory, and genetic algorithm is used to find the optimal semi-active switching to drive the structural state point to sliding mode switching band at prestissimo speed.

提出了一种瞬时最优半主动结构控制方法，利用滑模变结构控制理论和Lyapunov稳定性理论设计使结构瞬时能量最小的半主动控制权矩阵，仿真实例和振动台试验验证了本文所提方法的有效性和实用性；为解决在高层建筑半主动控制中半主动控制器状态组合爆炸的问题，利用滑模变结构控制理论设计在Lapunov稳定意义下使结构在运动状态空间中任一相点于以最快速率到达滑模切换带的半主动控制策略，并用遗传算法找出了最快到达滑模切换带的半主动控制切换组合。

In the work, employing a function with four undetermined parameters to model the source wavelet, an analytical relation between Q-factor and envelope peak instantaneous frequency is derived from the theory of one-way waves propagating in an anelastic medium; at the same time, a method for extracting instantaneous frequency in wavelet domain is developed for improving the precision and anti-noise performance of IF estimation, and based on these, a method called EPIF in wavelet domain is proposed for estimating Q-factor of VSP data.

本文采用一个具有4个待定参数的函数去逼近震源子波，利用黏弹介质中单程波传播理论推导出了地震子波包络峰值处瞬时频率和品质因子之间的解析关系；同时，为提高瞬时频率的估计精度和抗噪性能，在小波域中发展了一种计算瞬时频率的方法，并在此基础上提出了估算VSP资料Q值的方法，简称小波域包络峰值处瞬时频率法。

Finish to design the micro CNC, I have to investigate the adaptable parameters for cutting. This paper had calculated tool's radius, spindle's rotational speed, radial depth, and feed speed by the instantaneous cutting areas of the cutting forces model. To find out the instantaneous cutting areas by mathematica which can calculate the tangential, radial and axial component of cutting forces during cutting.

设计完微型工具机后，接著探讨最佳的切削参数，本论文采用瞬时投影面积的数学模型，且推导出利用刀具半径、主轴转速、径向切深、进给速度等参数来做为瞬时切削投影面积的函数，并使用软体mathematica算出瞬间面积大小，预测出切削过程里所产生的切线切削力、径向切削力和轴向切削力。

With Matlab simulation software, a research on simulation of harmonic detection means based on instantaneous reactive power theory is carried out, and a detailed analyse of the simulation result is presented. The result indicates: the harmonic detection means based on instantaneous reactive power theory can detect harmonic and reactive component in three-phase current precisely and re...

利用Matlab仿真软件，对基于瞬时无功功率理论谐波检测方法进行了仿真研究，并对仿真结果进行了较为详细地分析，仿真结果表明：基于瞬时无功功率理论谐波检测方法可以准确、实时地检测出三相电流中的谐波电流及无功电流，可为抑制谐波和无功补偿提供可靠的谐波及无功电流分量。

In chapter 1, an up to now synthetically evaluation is given on the research ways and conclusions about jet in cross-flow. Considering the shortage of previous research ways and techniques (the instantaneous flow field and vortices field can not be properly get), in addition to the deficiency of corresponding conclusion (mainly concentrate on the analysis of time-average but little on structures of flow and action of vortex), the research way and content is draft out in this part. Though PIV, the time-average, instantaneous flow field and vortices field can be get, that will unveil the coherent vortex and its course of generation, development and evolvement, with the assistance of K-ε model and Hybrid Finite Analytic Method , which will proof-test the experiment result and bring some complementary, more profound research about the 3-D characters can be done. Using some fundamental topological theory and principle on flow analysis, with anglicizing of vortex structure, a reasonable description is the topological characteristic of near field in JICF given.

首先在第一章中对横流中湍射流的以往研究方法和研究成果给予了综合的评述，针对横流中湍射流旋涡结构以往研究中研究方法的局限性（不能很好得到流动的瞬态流场及涡量场）和相应研究成果中存在的不足（大都集中在时均特性的分析，对流动的内部结构和旋涡的运动阐述很少），明确了本文的研究方法和研究内容：通过PIV流动测量显示技术得到流动的时均及瞬态流场、涡量场，来揭示横流中湍射流的时均、瞬态流场、涡量分布特性，和各种具有拟序结构性质的复杂涡系的产生、发展及演化过程；结合湍流k-ε双方程模型及相应的HFAM计算方法，对于实验进行相互验证和补充，从而更为充分地研究各种旋涡的三维特性；利用拓扑分析的一些基本原理及相关规则，依据对各种旋涡结构的分析，做出对射流近区流场拓扑性质的合理描述。

When I wake from such feeling, I find the holding fish only remained a skin. This merely is the matter which instantaneous occurred, so that such whitebait has disappeared. I not only have absorbed whitebait's all strengths, but also have absorbed its memory and painful and struggled sense facing instantaneous

当我从这样的感觉中醒来，发现手里的鱼已经只剩一层皮了，仅仅是瞬间发生的事，一条冰鱼就这么没有了，我不仅吸收了冰鱼的所有力量，还吸收了冰鱼的记忆和那瞬间冰鱼临死前痛苦和挣扎的感觉。

It is introduced that harmonic current in the electric network and harmonic current detecting method based on instantaneous reactive power theory in the paper,and then it presents the current detecting method in the anisomerous mains voltage,aberrance circuit based on instantaneous reactive power theory .

通过对电网谐波和瞬时无功功率理论在谐波检测中应用的分析研究，作者给出了基于瞬时无功功率理论的检测方法在电网电压不对称、存在畸变时的电流检测方法。

The contributions of this paper are followed:1 IntroductionIntroduce the concept "Blind" and present MEMO blind source separation model.2 Research on the instantaneous mixture systemReview the techniques developed for the demixing of the instantaneous mixture case.3 Research on the linear convolutive systemModel the linear convolutive system and review the deconvolution approaches in time domain.4 Introduce a new method to MIMO BSSA new approach to MIMO blind source separation in frequency domain is introduced, experimental tests are conducted,and results are satisfied.

论文包括了以下几个部分： 1。简介介绍&盲&的概念，并对瞬时混合盲源分离系统进行建模。 2。对瞬时混合多输入多输出系统的研究对瞬时混合系统的盲源分离原理和技术进行了简单的回顾。 3。对线性卷积混合系统时域算法的研究对线性卷积混合系统建模，并对时域的盲解卷方法进行研究和比较。 4。提出了一种对线性卷积混合系统进行分离的新方法提出一种多输入多输出线性混合系统的频域盲源分离方法，进行仿真实验，以验证该算法的效果，初步结果令人满意的

Breath, muscle contraction of the buttocks; arch body, as far as possible to hold his head, right leg straight towards the ceiling (peg-leg knee in order to avoid muscle tension).

呼气，收缩臀部肌肉；拱起身体，尽量抬起头来，右腿伸直朝向天花板（膝微屈，以避免肌肉紧张）。

The cost of moving grain food products was unchanged from May, but year over year are up 8%.

粮食产品的运输费用与5月份相比没有变化，但却比去年同期高8％。