查询词典 variance

The optimal number of principal component is decided by minimizing the total unreconstructed variance in this paper.

本文选用最小不可重构方差法来选取最优主成分数。

The variance of optic nerve head parameters appears to be attributable to additive genetic and unshared environmental effects.

视神经乳头参数的变异由加性遗传和独享环境因素共同决定。

Upper control limit for exposure point concentration of formaldehyde was calculated by Land method based on maximum likelihood estimates and Chebyshev method based on minimum variance unbiased estimates, and UCL values were 35.18 mg/kg and 41.82 mg/kg, respectively.

采用最大概似估计的Land方法及最小方差无偏估计的Chebyshev方法计算得到甲醛暴露点浓度控制上限，分别为35.18、41.82 mg/kg。

The wavelet variance verification also indicates that the first main period of the runoff of mountainous watershed in the Shiyang River Basin is 30years, and 22years and l5years are the second and third period respectively; 3 Then we also compared the total runoff of mountain watershed with climate factors of Wushaoling which station is in the mountain headstream area, such as precipitation and temperature, the data record that the correlation coefficient of annual runoff and precipitation variation over the upper reaches in the Shiyang River Basin is 0.61 ,which indicates precipitation is the main water recharge of the runoff.

石羊河流域出山口年径流的周期变化与乌鞘岭站年降水量和年均气温周期基本上都能在同一周期上下浮动，其中出山口年径流量与乌鞘岭山区年降水量相关系数为0.61，说明地表径流量主要是由山区降水补给；年径流量与山区年均气温变化呈0.28的反相关，说明该流域近50年来出山口径流与山区气温呈反比，即径流量随年均气温上升而减少，相关性暂时不十分明显。

The activity of Urase and Sucrase in different degradation stages showed significant variance (P.05); the activity of Urase in different soil layers were significant P.

草甸退化使土壤脲酶和蔗糖酶活性出现了显著变化(P.05)，脲酶活性在不同土层间差异显著(P.05)，蔗糖酶没有表现出土体层次性差异；相关分析表明，高寒草甸的土壤酶活性与营养成分含量之间相关不显著。

According to the sensitivities of variance coefficients and relative range of soil properties, we found that nitrate, available phosphorus, labile organic matter, urase, invertase, and organic matter can be used as the assessing index, which can evaluate soil quality under various re-vegetation ecosystems in the Loess Plateau.

根据变异系数和相对极差的敏感性发现在定量评价黄土高原不同植被恢复生态系统土壤质量时，可选择硝态氮、速效磷、活性有机质、脲酶、蔗糖酶和有机质等极敏感和高度敏感土壤性质作为评价指标。

In the second chapter, we introduce utility theory, mean-variance model, VAR method, rate of return.

第二章首先介绍了效用理论、由Markowitz提出的均值—方差模型、VAR风险管理方法、收益率分布问题，在Markowitz的均值—方差模型的基础上，重新定义了证券收益的风险，提出了一个新的用于资产配置的模型，这主要是为了实现规避风险进行分散化投资。

The research is about the reuse of urban sewage for virescence irrigation, and the influence of sewage irrigation on eco-environment such as soil, plant, etc. is studied. Under the condition of field sewage irrigation, the transport and transformation and accumulation mechanism of heavy metals, nutrients and organic pollutants as vaporizable hydroxybenzene etc. in the soil-plant system are analyzed. The heavy metal pollution is evaluated by the comprehensive pollution index. The spatial variability of heavy metals in sewage irrigation area is further understood. The spatial variability of heavy metals and physical and chemical properties of soil are reflected in a more straight way by the theory model of variance function curve based on the geographical information system.

在城市污水回用于绿化灌溉对土壤、植物等生态环境的影响研究中分析了大田条件下污灌对土壤-植物体系中重金属、养分及挥发酚等有机污染物迁移转化及富集机理，对重金属污染进行了综合污染指数评价，进一步了解了污灌区重金属分布的空间异质性，基于地理信息系统提出了变异函数曲线的理论模型，更直观地反映出了重金属元素与土壤理化参数的空间变异特征。

In the part of empirical study, by using variance analysis with the companies diversified operating and performance.

本文在实证部分运用方差分析对多元化经营与公司绩效的关系进行了分析。

In the last part, simultaneously analyzed three types of weak-form market efficiency tests-auto regression, run tests and variance ratio test for various data frequencies, perform the tests on both the Shanghai and Shenzhen markets for a period of more than six years.

第三章中，本文运用自回归、游程检验和方差比检验三种模型分别对我国上海股票市场和深圳股票市场的弱式有效性进行分析。

The split between the two groups can hardly be papered over.

这两个团体间的分歧难以掩饰。

This approach not only encourages a greater number of responses, but minimizes the likelihood of stale groupthink.

这种做法不仅鼓励了更多的反应，而且减少跟风的可能性。