基于组合预测模型的工业增加值中长期预测方法研究

工业增加值的准确预测已日益受到人们的关注。在这篇论文里,首先考虑运用相似复合体模型进行建模,然后运用具有最优停止法则的GMDH自回归方法和非线性的SPSS曲线估计方法建立单一模型。最后,用基于误差平方和最小的多元线性回归模型方法对各种单一模型的预测值进行组合,得到最优模型。通过实证研究可以发现,在中长期的工业增加值预测中,组合预测模型取得了较为满意的效果。

Investigation of acoustic scale effects and boundary effects for the similitude model of underwater complex shell-structure

In this paper, the acoustic scale effects and boundary effects for the similitude model of underwater complex shell-structure are investigated. The similitude conditions and relations between the similitude model and its prototype were studied in the references. This paper investigates the acoustic scale effects for the similitude model, which are influenced by loss factor, shear and rotatory inertia. At the same time, the boundary effects which are influenced by surface sound reflection are investigated in the experiment of similitude model. The results show that the acoustic scale effects may be controlled with model designing, the boundary effects can be controlled with experimental designing between the similitude model and its prototype.