1)  Mean-Variance Model
均值一方差模型
2)  mean
均值
1.
Improving methods to calculate estimator minimum variance of the finite population mean;
总体均值估计量最小方差的改进
2.
The parameter Estimation Based on Mean Absolute Deviation;
基于均值绝对离差的参数估计
3)  average
均值
1.
In some applications of neural networks, such as failure detection based on neural networks, both the average and the standard deviation of mean squared prediction errors are needed to be small.
在基于神经网络的故障检测中 ,要求神经网络拟合某特定动态系统时均方预测误差的均值及其标准差均小 ,故在以均方预测误差的均值作为评价神经网络逼近特定动态系统性能的系统化交叉证实法的基础上进行改进 ,以均方预测误差的均值和标准差两个指标评价神经网络逼近特定动态系统性能 。
2.
From the perspective of Gaussian distribution and stable distribution, and in the form of variance and average, the computing methods for return and risk of portfolio are compared.
从高斯分布和稳定分布角度, 以均值和方差的形式, 比较资本投资组合收益及风险的计算方法, 从中指出稳定分布的表象更切近于资本资产价格运动的现实表现。
3.
Nine kinds of combining strategies are experimented in this paper:product,average,max,min,majority voting,rank-based voting,weighted voting,weighted probability,and best single combining,among which the three combining metho.
9种集成方法分别是乘法规则、均值、最大值、最小值、多数投票、序列投票、加权投票、概率加权和单分类器融合,其中乘法规则、均值、最大值3种集成方法还未曾应用于词义消歧。
4)  average value
均值
1.
Three exercisable algorithms,average value regulation,range transformation and the combination methods,are presented.
提出了3种实施性较强的算法:均值平移法、区间变换法和组合法。
2.
The average value and covariance formulas of the stress intensity factor for a penny-shaped crack embedded in a fiber of the composite material are deduced.
基于级数展开技术导出随机边界元法,并将随空间坐标随机变化的材料或几何参数模型化为随机变量或随机场,从而导出纤维内含圆盘状裂纹应力强度因子的均值和协方差的公式,并用来求解承受均匀拉伸的复合材料纤维内含圆盘状裂纹的同轴双圆柱体的应力强度因子,分析了基体与纤维的弹性模量比对应力强度因子的影响,算例表明本文方法是可行和有效的。
5)  mean value
均值
1.
On the mean value of smarandache function d_f(n);
关于Smarandache函数d_f(n)的均值
2.
On the lucas number and its furth power mean value;
关于Lucas函数的四次均值计算
3.
On the mean value of a number theoretic function;
一个数论函数的均值问题
6)  Expectation
均值
1.
The expectation and variance of damage probability in known intensities are calculated by making the probability disperse.
通过将破坏概率离散化得出一次地震中各烈度下震害指数的均值和方差,对比其与标准震害矩阵相应烈度下的值,得到其他烈度下震害指数的均值和方差。
2.
To some extent,expectations and covariances can.
均值和协方差一定程度上可以描述这些随机变量的概率分布特性。
3.
The state vector s expectation, variance and covariance matrices are given under the conditions of the systems with regular infinite extreme point and singular infinite extreme point.
在系统具有正则无穷远极点和奇异无穷远极点的条件下,得到了系统状态向量的均值、方差阵及协方差阵的计算公式。
参考词条
补充资料:方差估计值
分子式:
CAS号:

性质:由样本测定值计算的方差S2,称为样本方差,S2是总体方差σ2的无偏估计值。因此,S2又称为方差估计值或估计方差。S和σ分别为样品测定值的标准差和样本总体呈正态分布的标准差。

说明:补充资料仅用于学习参考,请勿用于其它任何用途。