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基于改进的Adaboost-BP模型在降水中的预测研究

王军1,费凯1,程勇2   

  1. 1. 南京信息工程大学
    2. 南京信息工程大学 网络信息中心,南京 210044
  • 收稿日期:2017-03-15 修回日期:2017-05-18 发布日期:2017-05-18
  • 通讯作者: 费凯

Research on prediction of rainfall based on improved Adaboost-BP model

  • Received:2017-03-15 Revised:2017-05-18 Online:2017-05-18
  • Contact: fei kai

摘要: 针对目前分类算法对降水预测过程存在着泛化能力低、精度不足的问题,提出改进Adaboost算法集成反向传播(Back-Propagation,BP)神经网络组合分类模型,该模型通过构造多个神经网络弱分类器,赋予弱分类器权值,将其线性组合为强分类器。改进后的Adaboost算法以最优化归一化因子为目标,在提升过程中调整样本权值更新策略,以此达到最小化归一化因子的目的,从而确保增加弱分类器个数的同时降低误差上界估计,通过最终集成的强分类器来提高模型的泛化能力和分类精度。选取江苏境内6个站点的逐日气象资料作为实验数据,建立七个降水等级的预报模型,从对降雨量有影响的众多因素中,选取12个与降水相关性较大的属性作为预报因子。通过多次试验统计,结果表明基于改进的Adaboost-BP组合模型具有较好的性能,尤其对58259站点的适应性较好,总体分类精度达到81%,在七个等级中,对0级降雨的预测精度最好,对其它等级的降雨预测有不同程度的精度提升,理论推导及实验结果证明该种改进可以提高预测精度。

关键词: 关键词: 分类器, 改进Adaboost, BP神经网络, 组合模型, 权值调整, 归一化因子

Abstract: To solve the problem that it has poor generalization ability and low precision in the existing classification algorithm. the multi- classification combination algorithm was proposed, The model had integrated the neural network weak classifiers, the weak classifiers were distrbuted the weightand those classifiers were combined linearly into the strong classifier.In the process of weight iteration, the target of improved Adaboost algorithm was optimization the normalization parameter, and adjusted the strategy of samples updating weight, so that, It could ensure decreasing the error bound estimation as the weak classifiers were increasing ,the strong classifier integrated had been used to improve the prediction accuracy of model. Seven levels predication model had established, it had selected the daily meteorological datas which was six stations of Jiangsu Province, the 12 relative factors had been selected for important factors about rainfall, Through several experiments, the results show that the improved Adaboost-BP model has better performance, it is suitable for station of 58259 especially, the accuracy of overall samples is 81%,in the seven rainfall class, the accuracy of the class-0 rainfall is the best, the accuracy of other classes prediction have been improved, theoretical derivation and experimental results show that the improved algorithm can improved the accuracy of prediction.

Key words: Keywords: classifier, improved Adaboost, BP neural network, combined model, weight adjust, normalization parameter

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