Stand density index (SDI) was applied as a quantitative index to measure mean crowd degree between trees.

选择林分密度指数(SDI)作为反映林分中林木之间平均拥挤指标。

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LSFG values were used to calculate the square blur rate (SBR), which is a quantitative index of relative blood flow velocity.

用LSFG值来计算平方模糊率(SBR)，这是一个相对血流速度的定量指标。

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The concept of health degree was defined, which is used as a quantitative index for evaluation of the health condition of liquid hydrogen supplying system.

提出了液氢供应系统健康状况的定量综合评价指标———健康度，将基于模糊集的数据融合方法用于健康度的计算。

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It says that most investors would be better off simply buying a low-cost index fund that holds all the securities in the market rather than using either quantitative models or intuition in an attempt to beat the market.

WSJ: Book Review: Models Behaving Badly