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曲线拟合是混凝土质量控制中常用的方法,它是采用最小二乘法(加权或等权)估计参数的。从理论上讲,当拟合变量的方差不等时,应该用加权最小二乘法求参数的估计量,但是这种方法的计算麻烦,常常必须用计算机进行最优化计算才能解决,并且还存在权的估计准确性对计算结果影响的问题。而等权最小二乘法求得的参数的估计量,虽然统计性质(如有效性)较加权方法差,但其步骤简单,用一般计算器就能进行计算。因此,在工程应用中常常不论是否应该用加权方法,都用等权最小二乘法估计参数。那么,在混凝土质量控制常用的范围内,加权与等
Curve fitting is a commonly used method in the control of concrete quality. It uses least squares (weighted or equal weight) to estimate parameters. Theoretically speaking, when the variance of the fitted variables is not equal, the weighted least-squares method should be used to find the estimated value of the parameters. However, the calculation of this method is inconvenient, and it is often necessary to use a computer to perform the optimization calculation to solve the problem. The accuracy of the estimate affects the calculation results. While the estimated quantity of the parameters obtained by the equal least-squares method is worse than the weighting method in statistical properties (eg, effectiveness), the steps are simple and can be calculated using a general calculator. Therefore, in engineering applications, parameters are always estimated by equal weight least squares, whether or not they should be weighted. Well, in the common range of concrete quality control, weighted and other