查询词典 ordered sample

Five ways on comparing covariance matrix are applied to the Shanghai 50 Indexes Stock Exchange, which are sample covariance matrix, scalar matrix, two-parameter covariance matrix, single index matrix, constant correlation matrix. We adopt principal components method and Markowitz portfolio method to measure stock market risk using VaR, getting the effect of measuring market risk. The result shows that sample covariance matrix and two-parameter covariance matrix could measure market risk more effectively.

本文以上证50指数数据为样本，采用样本协方差矩阵、数量矩阵、两参数模型矩阵、单指数模型矩阵、常量相关矩阵作为与股票相关的协方差矩阵，结合投资策略选择的主成分方法和Markowitz最优投资组合方法，计算VaR以度量市场风险，并比较了五种协方差矩阵度量市场风险的效果，结果表明，在主成分方法中，样本协方差矩阵和两参数矩阵方法能有效的度量市场风险。

The slope estimate is the sample covariance between x and y divided by the sample variance of x.

斜率估计量等于样本中x和 y 的协方差除以x的方差。若x和 y 正相关则斜率为正，反之为负。

Also, a traditional test method is proposed by the Bartletts decomposition of sample covariance matrices and the sample mean vectors.

另外本文还利用样本协方差矩阵的Bartlett分解和样本均值，给出了检验共同均值的一种传统方法，这种检验犯第一类错误的概率比标称的检验水平略低。

X-ray ; Fluorescence spectrometer ; Energy dispersion ; Sample preparation ; Standard sample

X射线；荧光光谱；能量色散；样品制备；标样

The sample is subjected to primary dispersion by a primary dispersion flow that reaches a critical pressure and a subsonic speed, and the sample is then subjected to a secondary dispersion by a secondary dispersion flow that is different in direction from the primary dispersion flow and that reaches a critical pressure and a subsonic speed.

该试样受到达到临界压力和亚音速的初次分散流的初次分散，然后试样接受与初次分散流方向不同且达到临界压力和亚音速的二次分散流的二次分散。

One embodiment estimates a transmitted symbol from a received sample as a function of Signal-to-Interference and Noise Ratio of the received sample.

一个实施例根据接收采样的信号对干扰和噪声比的函数从接收采样中估计出发射的码元。

A kind of probability sample in which a set interval is applied to a list often population to identity elements included in the sample (e.g., picking every 10th name).

以一定的间隔来从人口名单中抽取所需的样本(如：每隔10个人抽取一次)。

Then the influence of sample interval and slit width on the transmission spectra was analyzed, and the suitable sample interval and slit width for measuring porous aluminium coating with copper were achieved.

测试结果表明：对镶嵌铜多孔铝膜而言，在可见光波段选择3nm的狭缝宽度和0.5nm或1nm的取样间隔为宜；在近红外波段选择5nm或8nm的狭缝宽度和2 nm的取样间隔为宜。

Sample median: the value of sample value or sampling.

采样位数：即采样值或取样值。

If you would like to use a sample letter as a starting point, choose Use sample content.

如果需要使用范例文本作为起点，选择"使用范例内容"。

Many will continue to choose to live in duality and in conflict.

许多人将继续选择活在二元对立性和冲突中。

I find that students of the University of Physical Education all wear sportswear at first sight.

我发现：体育大学的学生乍一看，都是穿运动衣，大家都一样