The change of coal thickness caused by geological structure is nonlinear and revulsion, but in a certain range, the mathematicalexpectation of coal thickness distribution is a fixed value.
由构造引起的煤厚变化具有非线性特征和突变性，但在一定的范围内，煤厚分布的数学期望为一个固定值。
2
When the market is complete, the present value of any derivative security is equivalent to mathematicalexpectation of its underlying profit discount value under equivalent martingale measurement.
当市场是完备时，任意衍生证券的现值等于该证券未来收益折现值在等价鞅测度下的数学期望。
3
Build mathematical model of quantitative analysis, confirm the expectationvalue of light intensity, build standard work curve, improving analysis precision.