first second-order matrix

• 一次二阶矩

first second-order matrix的用法和样例：

例句

1. The parameters of the model are fuzzily processed and the fuzzy risk can be evaluated by using the modified first order second moment method.
   通过对模型中的参数进行模糊化处理，用改进一次二阶矩法计算了地下水过量开采的模糊风险率。