查询词典 zero method

Due to its good effect in the reservation of information of signal abrupt change, mathematical morphology is often applied in the detection and location of short-term power quality disturbance, however, there is still a defect of invalid detection existing in partial detection methods based on mathematical morphology while some zero-crossing disturbances are detected. In this paper three mathematical morphology based disturbance detection and location methods, i.e., the method based on first-order derivation and morphological gradient, the method based on morphological gradient and soft threshold processing and the method based on dq decomposition and top-hat transform, are analyzed, that is, by means of simulation the adaptability of these methods in the analysis on the signals of voltage sag, voltage swell and electromagnetic transient oscillation is compared.

数学形态学因其在保留信号突变点信息方面有很好的效果，因此常用于短时电能质量扰动的检测和定位，但基于数学形态学的部分方法仍存在对某些过零点扰动检测失效的缺点，文章分析了3种基于数学形态学的扰动检测和定位方法，即基于1阶求导和形态梯度的方法、基于形态梯度和软阈值处理的方法、基于dq分解和高帽变换的方法，通过仿真比较了3种方法在分析电压暂降、电压暂升、电磁暂态振荡等信号方面的适应性，结果发现基于dq分解和高帽变换的方法在检测过零点扰动时具有很好的效果，因此选取这种方法对实测扰动数据进行了检测和定位分析。

Currently parts of serieses productthe resin method super and hard emery wheel,the porcelain quality method the super and hard emery wheel,the metals method(the bronze burn knot and electroplate Ni super and hard emery wheel and diamond roll a round in my company, extensively applied in precise molding tool,machine electronics,automobile zero partses,metal alloy tools,porcelain and ceramicses seal completely professions, such as piece and the magnetism material...etc.

目前我公司中的部分系列产品（树脂法超硬砂轮、瓷质法超硬砂轮、金属法超硬砂轮和金刚石滚轮），广泛应用于精密模具、机械电子、汽车零部件、合金工具、陶瓷密封件和磁性材料等行业磨削加工，在客户中已建立起良好的信誉，是进口品牌砂轮理想的替代品，并已批量出口国外市场。

Firstly, the natural frequencies and normal mode shapes of the fluid-conveying pipe with zero fluid velocity (i.e. U=0) were determined with the transfer matrix method. Next, these natural frequencies and normal mode shapes were used to derive the equation of motion for the fluid-conveying pipe with fluid velocity U.neq.0 by using the expansion theorem. Finally, the free and forced vibration responses of the pipe with flowing fluid were obtained by means of the Jacobi method and the Newmark direct integration method.

首先吾人使用转移矩阵法来求取一流速等於零(即U=0)、跨距数为N之流体输送管的自然频率及其所对应之正规化振态，然后利用振态重叠法原理来推导流速不等於零(即U.neq.0)时，整个流体输送管在外力作用下的运动方程式，最后再以Jacobi法及Newmark直接积分法来计算该水平流体输送管的自然频率及强迫振动反应。

From the perspective of minimum transmission losses, an instantaneous reactive power theory for systems with any number of phases and with or without neutral line is developed. Under the new definition, each quantity has its own physical meaning, and the zero sequence current can be decomposed into active and reactive components. Furthermore, a generalized compensation method for zero sequence current is developed.

从输电损耗最小的角度出发，提出了任意相无中性线或有中性线系统的瞬时无功功率理论，在新的理论下，每个量都有清晰的物理意义，且能分解出零序电流的有功分量和无功分量，并给出了通用的零序电流补偿方法，揭示了瞬时无功功率理论与传统平均意义下的无功功率理论的联系及本质区别，从而为研究HVDC-VSC及各种FACTS装置的无功功率控制奠定了理论基础。

The system state transition matrix is deduced, so the zero effort miss of the interceptor can he solved with numerical method under considering the earth's oblateness effect of J2. In order to make the thrust direction change smoothly and make the zero effort miss decrease quickly, the engine thrust is decomposed along the line of sight direction and perpendicular to the line of sight direction, and the distribution proportion coefficient is designed based on the required velocity gain normal to the line of the sight.

推导了系统状态转移矩阵，通过数值方法求解得到考虑地球扁率J2摄动项的拦截器零控脱靶状态，在此基础上将推力分解到视线方向和垂直视线方向，并根据垂直视线方向需要速度增量大小设计了推力分配比例系数，使得推力方向平稳变化且能快速减小系统的零控脱靶量。

A new SVM method suitable for four-switch inverter fed PMSM DTC system was proposed. By analyzing the property of the equivalent zero space vector and its imitation scheme in detail, the paper introduced a zero-vector partition idea, which is usually adopted in the SVPWM modulation, to the composition of desired space vector.

该文针对四开关逆变器供电PMSM DTC系统的特殊性，采用了一种新型SVM方法，分析了等效零矢量模拟技术，将传统SVPWM调制中的劈零思想引入到空间矢量的合成上。

The difference is discussed in the paper and a novel PMSM DTC system based on the fuzzy distribution of zero voltage vector strategy is proposed at last. Simulation results show that the new method decreases the torque ripple after using zero voltage vectors properly.

论文分析了零电压矢量在永磁同步电机直接转矩控制系统中的作用，并提出了一种基于模糊零电压矢量分配策略的永磁同步电机直接转矩控制方法，仿真结果表明该方法有效地利用零电压矢量达到了减小转矩脉动的目的。

According to the modified Rytov method for the optical wave propagation and withconsidering the effect of the turbulence spectrum model with zero and non-zero innerscale in addition to the finite outer scale, the solution to the scintillation index as afunction of the Rytov variance is obtained from weak to strong fluctuation regions forGaussian beam propagation along the horizontal path.

根据光波传播的修正Rytov 方法，得到了高斯波束水平传输时在零内尺度湍流谱模型及考虑湍流内尺度效应和外尺度效应条件下，从弱起伏湍流区到强起伏湍流区闪烁指数随Rytov 方差变化的计算公式。

By employing the Jordan-Wigner transformation and a modified mean field method, we are able to determine its ground-state quantum phase diagram approximately. The chapter IV is the main part of this Thesis. It contains the main innovations in our work. We propose and study in detail a S=1 Ising chain with the interplay of single-ion anisotropy and dimerization. The main results and innovations are the following: We show that the total number of the zero-component of spins at each site is a conserved quantity. This quantity, which may intuitively called as hole's quantum number, is hidden in the system. We show further that the hole's number in the ground-state is zero; By using the Jordan-Wigner transformation, we map this model onto a series of subsystems described by the spin 1/2 dimerized transverse Ising model. We solve the subsystems exactly, by presenting the exact wave functions and spectra;We show that this system exhibits a series of quantum phase transitions by varying the dimerization strength. We determine the quantum critical points exactly. We also show that the criticality is the same as that of the uniform S = 1/2 transverse Ising chain.

第四章是本文的重点及主要创新内容，我们具体研究了自旋为1的在横向单离子晶格场中的一维二聚化Ising链，我们得到的主要结果和创新之处是：(1)证明了这一模型具有一种隐藏的对称性，即自旋第三分量为零的格点数目是一个守恒量，并证明基态出现在空穴数目为零的子空间中；(2)利用Jordan-Wigner 变换将此模型变换到一系列自旋为1/2的横磁场中的二聚化Ising 模型，并给出了相应严格的波函数及能谱；(3)我们发现系统的基态随着二聚化强度的变化将呈现出一系列量子相变，我们得到了量子临界点的精确位置，并证明其临界性质与自旋为1/2的横磁场中的均匀Ising 链中的临界行为属于同一普适类。

To reduce and compensate the influence of temperature on ring laser gyro bias error and attain the precision of inertial level gyro, the mechanism of RLG zero-bias error due to temperature is analyzed. Based on a great number of environmental temperature experiments of RLG, a general temperature compensating model and a new kind of BP neural network model are established. A method for identifying the model parameter is proposed. Simulation results show that the simplified compensating model can reduce the zero-bias by more than a magnitude and achieve real-time compensating feature.

零偏是衡量激光陀螺性能的一个重要指标，但其受温度影响很大，为了降低和补偿温度对激光陀螺零偏的影响，使其达到惯性级陀螺仪的精度要求，分析了温度对激光陀螺零偏误差的产生机理，在大量高低温环境试验的基础上，建立了一种通用的零偏温度补偿模型和一种BP神经网络模型，并给出了模型参数的辨识方法，仿真结果表明，对该模型作适当的简化，可以将零偏减小一个数量级以上，而且具有实时补偿性能。

On the other hand, the more important thing is because the urban housing is a kind of heterogeneity products.

另一方面，更重要的是由于城市住房是一种异质性产品。

Climate histogram is the fall that collects place measure calm value, cent serves as cross axle for a few equal interval, the area that the frequency that the value appears according to place is accumulated and becomes will be determined inside each interval, discharge the graph that rise with post, also be called histogram.

气候直方图是将所收集的降水量测定值，分为几个相等的区间作为横轴，并将各区间内所测定值依所出现的次数累积而成的面积，用柱子排起来的图形，也叫做柱状图。