Through the histogram method and Kolmogorov test,it was obtained that the sensitivity coefficient of variation for D6-2 artillery primer and mechanical explosive devices approximated the normal distribution of(0.

The results show that the rainfall isogram in the area of Beijing has been densified by the urbanization, and then the annual rainfall has been increased as well; which makes the change of the coefficient of variation of urban rainfall is larger than those of the suburbs.

Based on the date of Chaohu river network of waterways area 8 survey station of many year materials,The relations between,its flood peak and the year of the largest flood runoff one day is established,its corresponding coefficient of variation Cv value is calculated and the distribution rule and origin of the Cv value is analyzed.

The optimum design example shows that the variation coefficient of load torque acting on cutting head is decreased 13.

The Analysis shows that the bigger the variation coefficient of dependent variable,the bigger the mean square error of regression equation when the multiple correlation coefficient(or correlation coefficient) is definite.

Mathematical expectation,variation coefficient and probability density function were analyzed or simulated to investigate the variation trend and characteristics of daily precipitation in the area.

By applying multiple central limit theorem,it′s proved that difference of variation coefficient of two normal distribution is asymotic normality.