查询词典 variance ratio

This article first discusses the significance of homogeneity of variance, then studies the general method of transformation for homogeneity of variance on the relation between the data mean and the variance when population distribution is known ,and it uses the Mathematica software to analyse the variety rules between the parameter and the variance in the corresponding transformation.

从方差非齐性数据处理中的变换的必要性入手，根据数据均值与方差之间的关系研究了总体分布已知时的方差齐性变换的一般方法，并利用Mathematica软件分析相应变换中参数与方差之间的图形规律，最后介绍了总体分布未知时的BoxCox变换的一般原理。

Therefore, just like the direct material variance, when the labor cost for a task differs from standard, the direct labor variance can be divided into a labor efficiency variance and a labor rate variance.

正像直接材料差异那样，对一项工作的实际成本与标准成本之间的比较，直接人工成本也可以分成工时量差异和工资率差异两部分来分析。

The measurement system error model analysis is introduced into power system real time network state analysis as an important part for the first time, which can improve on the state estimation quality and provide the capability to monitor the operation of the measurement system; 2. The theory and algorithm of the on-line estimation and update of measurement noise variance based on the relation between the residual variance and noise variance. The statistic properties of the sample variance are discussed and the relation between the estimation precision and sample size under given confidence level is derived; 3. The theory and algorithm of detection and identification of measurement bias are presented, which is based on the relation between residual mean and noise mean. The statistic properties of sample mean are discussed and the relation between estimation precision and sample size is derived; 4. The Givens orthogonal transformation algorithm is selected to be the essential algorithm of state estimation, the fast orthogonal transformation algorithm with damp factor and the algorithm which can handle the zero injection measurements efficiently are presented; 5. The quantity analysis theory of bad data detectivity and identifibility are presented, which describes the relation between the elements in matrix W〓 and bad data amplitude and can provide the theory base for measurement system design and valuation.

一、首次将量测系统误差模型分析做为一个环节引入电力系统实时网络状态分析中，为EMS系统增加了实时监视系统运行、修正量测系统误差模型的新功能，进一步发挥了实时网络状态分析应用软件的潜力；二、首次提出了应用样本方差在线估计与修正量测系统误差方差的基本理论，讨论了样本方差的统计性质和概率分布，推导出了样本容量、估计精度和置信度之间的关系，给出了在线估计与修正量测系统误差方差的算法；三、首次提出了应用样本均值在线检测与辨识量测偏差的基本理论，讨论了样本均值的统计性质，推导了样本容量、估计精度和置信度之间的基本关系，给出了在线检测与辨识量测偏差的算法；四、在状态估计算法设计中，以Givens变换算法做为基本算法，提出了快速正交变换阻尼因子法和可以有效地处理零注入量测的混合法，并对实时应用中的一些问题进行了讨论；五、提出了不良数据可检测性与可辨识性的定量分析理论，揭示了描述量测系统配置、网络结构与参数的残差灵敏度矩阵中的元素与不良数据的幅值在可检测、可辨识能力上的定量关系，为量测系统配置设计与评价提供了理论基础；六、综合国内外最新研究成果，采用自适应自回归预测技术和稀疏矢量技术，构造了较完善的不良数据检测与辨识算法。

Based on the researches of system factors, system characters and the influence of market structure to market behavior, the chapter points out the characteristics and rules of china bond market system variance. On account of the Promoting Effect Government Dominated behavior, compellent system variance runs through the evolution of market structure and act on it. Although derivational system variance also works, it can't be the dominant because of the long variance time and high cost.

根据制度变迁理论研究债券市场结构的制度成因、特点及其对于市场结构和行为的影响，指出中国债券市场制度变迁的特点和规律，由于在中国债券市场的发展过程中，政府主导行为具有明显推动效应，强制性制度变迁始终贯穿于市场结构演变的过程中，并对其形成重要作用；诱致性制度变迁虽然也穿插其中，但由于其变迁时间长、成本高等特点，无法形成主导力量。

In each subperiod,the static rank variance and the static density variance of the population are defined,thus the DMOPs is transformed into several bi-objective static optimization problems by using the static rank variance and the static density variance.

然后把动态多目标优化问题近似地转化成了若干个两个目标的静态优化问题。在给出的一种能自动检测环境变化的应答算子下，提出了一种动态多目标进化算法，同时证明了算法的收敛性。

In this article, by exploiting flanking markers through the widely applied half-sib design, we have developed the structures of three variance components, i.e., variance component between marker genotypes, polygenic variance component and recombinant variance component within marker genotypes.

该文在侧翼标记情况下利用广泛使用的半同胞设计提出了3种方差组分，即标记组间方差、组内多基因方差和组内重组方差及其构成。

Correctional checking formula of melt flow ratio in injection molding was obtained by introducing a correction coefficient β which reflected the complexity degree of mold cavity. The results show that, the maximum flow ratio of 486 can be obtained when injection pressure ranges from 150 MPa to 160 MPa in Archimedes spiral mold for PP, while maximum flow ratio of 419 can be obtained when injection pressure ranges from 160 MPa to 170 MPa for PE. There is a local fluctuation phenomenon for flow ratio and corresponding injection rate in square spiral mold when injection pressure of 100, 120 and 150 MPa for PP and 130, 140 MPa for PE are reached respectively,and this phenomenon is more serious for good fluidity of melt. The average flow ratio in Archimedes spiral mold is 6% larger than that in square spiral mold for PP, and 4% for PE, the average flow ratio of PP is 19% bigger than PE in Archimedes spiral mold, and 15% in square spiral mold. The influence of the cavity profiles on the melt flow ratio is more significant for good fluidity of melt.

研究结果表明：在阿基米德螺旋线模具中，PP在注射压力为150~160 MPa时取得最大流动比485，PE在注射压力为160~170 MPa时取得最大流动比419；在方形螺旋线模具中，PP在注射压力为100，120和150 MPa，PE在注射压力为130和140 MPa时流动比及所对应的注射速率出现波动，且流动性好的熔体波动更为严重；PP在阿基米德螺旋线模具中的流动比均值较其在方形螺旋线模具中大6%，而PE大4%；在阿基米德螺旋线模具中流动比均值PP比PE的流动比均值大19%，而在方形螺旋线模具中PP的流动比均值比PE的大15%；流动性好的熔体受模具型腔轮廓特征影响大。

At first, setting up the arith relation between the signal input and the signal output of the generalized multi-carrier system of the Discrete Fourier Test spread-spectrum; then setting equilibria parameters of the frequency field equilibria subcarrier of the generalized multi-carrier system of the DFT spread-spectrum according to channel frequency response, channel noise variance and equilibria method; then calculating average power of useful signal, interferential average power between signals as well as noise variance of the generalized multi-carrier system receiving terminal of the DFT spread-spectrum according to the arith relation as well as the frequency field equilibria parameter, and recomputing available signal information noise ratio, so as to calculate the available signal information noise ratio of the generalized multi-carrier transmission system accurately, the method for estimating the available signal information noise ratio can be used for link self-adapting transmission solution of the generalized multi-carrier system based on Discrete Fourier Test spread-spectrum and radio material management.

一种DFT扩频的广义多载波系统的SINR估计方法，其通过首先建立所述离散傅立叶变换扩频的广义多载波传输系统的信号输入输出之间的数学关系，然后根据信道频率响应、信道噪声方差和均衡方法，设定所述DFT扩频的广义多载波传输系统的频域均衡子载波的均衡系数，再根据所述数学关系及所述频域均衡系数分别计算所述DFT扩频的广义多载波传输系统接收端有用信号的平均功率、信号间干扰的平均功率以及噪声方差，再计算有效信干噪比，如此以实现对广义多载波传输系统的有效信干噪比的准确计算，该有效信干噪比估计方法可用于基于离散傅立叶变换扩频的广义多载波传输系统的链路自适应传输方案和无线资源管理方面。

For the problem that the suppression of co-channel interference and suppression of noise can't be balanced in signal-to-jamming and noise ratio maximization method for the linear precoding of multiuser multiple-input multiple-output downlink systems, an improved scheme that the term of noise variance is modified as a piecewise linear function is proposed, in which the balance between suppression of co-channel interference and suppression of noise can still be maintained even when the noise variance is a small value through piecewise modifying the term of noise variance, and thus the bit error rate and capacity of the systems are further improved.

针对多用户多输入多输出系统下行链路线性预编码的信干噪比最大化方法中，共信道干扰抑制和噪声抑制不能有效平衡的问题，提出将其中的噪声方差项修正为以噪声方差为变量的分段线性函数的改进方案。该方案通过对噪声方差项的分段修正，在噪声方差的值较小时依然能够保持共信道干扰抑制和噪声抑制间的平衡，从而使系统的误比特率性能和容量得到进一步提高。

Our metrics of earnings management are based on the variance of the change in net income, the ratio of the variance of the change in net income to the variance of the change in cash flows, the correlation between accruals and cash flows, and the frequency of small positive net income.

收入管理我们的度规根据变化的变化在净收入上的，变化的变化的比率在净收入上的对变化的变化在现金流动上的，交互作用在增殖和现金流动之间和小正面净收入频率。

Finally it offers the analysis of the fault-tolerance system as well as its test verification.

这样，运行于空间环境中的系统的设计目标就是在保证系统实时性

However, it is still difficult to find out the real reason of the increase of the keratinized gingiva during the orthodontic extrusion whether it is due to the proliferation of the gingival tissue or to its elastic nature, that is because the proliferation of the fibroblasts as well as the connective tissue changes in volume and the intra-fibers spaces were all immeasurable in most of the studies.

然而，仍然难以找到真正的原因增加的角化牙龈在正畸挤压它是否是由于扩散的牙龈组织或其弹性性质，这是因为增殖的成纤维细胞以及作为结缔组织的变化量和内部纤维空格都是不可估量的，大多数的研究。