With the rapid development of the economy and industry and the improvement of pollution monitoring,how to accurately predict PM2.5 has become an issue of concern to the government and society.In the field of PM2.5 pol...With the rapid development of the economy and industry and the improvement of pollution monitoring,how to accurately predict PM2.5 has become an issue of concern to the government and society.In the field of PM2.5 pollution forecasting,a series of results have emerged so far.However,in the existing research field of PM2.5 prediction,most studies tend to predict short-term temporal series.Existing studies tend to ignore the temporal and spatial characteristics of PM2.5 transport,which leads to its poor performance in long-term prediction.In this paper,by optimizing previous PM2.5 deep learning prediction models,we propose a model GAT-EGRU.First,we add a spatial modular Graph Attention Network(GAT)and couple an Empirical Modal Decomposition algorithm(EMD),considering the temporal and spatial properties of PM2.5.Then,we use Gated Recurrent Unit(GRU)to filter spatio-temporal features for iterative rolling PM2.5 prediction.The experimental results show that the GAT-EGRU model has more advantages in predicting PM2.5 concentrations,especially for long time steps.This proves that the GAT-EGRU model outperforms other models for PM2.5 forecasting.After that,we verify the effectiveness of each module by distillation experiments.The experimental results show that each model module has an essential role in the final PM2.5 prediction results.The new model improves the ability to predict PM2.5 after a long time accurately and can be used as a practical tool for predicting PM2.5 concentrations.展开更多
基于压缩感知的K-means Singular Value Decomposition(K-SVD)图像去噪算法具有良好的自适应性和细节恢复能力,但需事先给定稀疏度K。该方法的去噪效果会受到图像稀疏度的影响。另外,训练初始系数时用到的追踪类算法中通过向量内积值的...基于压缩感知的K-means Singular Value Decomposition(K-SVD)图像去噪算法具有良好的自适应性和细节恢复能力,但需事先给定稀疏度K。该方法的去噪效果会受到图像稀疏度的影响。另外,训练初始系数时用到的追踪类算法中通过向量内积值的大小评定图像分量间相关度的方法,因存在大值噪声点,容易造成假相关,从而影响去噪效果。提出基于差异系数的稀疏度自适应K-SVD去噪算法,通过引入差异系数来平衡因噪声点造成的假相关问题,同时使用相关度均值作为阈值来自适应地产生稀疏度K,避免因给定不恰当的稀疏度而影响去噪效果的问题。在USC标准库上的实验结果表明,所提算法在去噪效果方面有一定的优越性。展开更多
基金This work was supported by the National Natural Science Foundation of China under Grant Nos.42071273,71671024 and 71874021Fundamental Research Funds for the Central Universities under Grant Nos.DUT20JC38,DUT20RW301 and DUT21YG119.
文摘With the rapid development of the economy and industry and the improvement of pollution monitoring,how to accurately predict PM2.5 has become an issue of concern to the government and society.In the field of PM2.5 pollution forecasting,a series of results have emerged so far.However,in the existing research field of PM2.5 prediction,most studies tend to predict short-term temporal series.Existing studies tend to ignore the temporal and spatial characteristics of PM2.5 transport,which leads to its poor performance in long-term prediction.In this paper,by optimizing previous PM2.5 deep learning prediction models,we propose a model GAT-EGRU.First,we add a spatial modular Graph Attention Network(GAT)and couple an Empirical Modal Decomposition algorithm(EMD),considering the temporal and spatial properties of PM2.5.Then,we use Gated Recurrent Unit(GRU)to filter spatio-temporal features for iterative rolling PM2.5 prediction.The experimental results show that the GAT-EGRU model has more advantages in predicting PM2.5 concentrations,especially for long time steps.This proves that the GAT-EGRU model outperforms other models for PM2.5 forecasting.After that,we verify the effectiveness of each module by distillation experiments.The experimental results show that each model module has an essential role in the final PM2.5 prediction results.The new model improves the ability to predict PM2.5 after a long time accurately and can be used as a practical tool for predicting PM2.5 concentrations.
文摘基于压缩感知的K-means Singular Value Decomposition(K-SVD)图像去噪算法具有良好的自适应性和细节恢复能力,但需事先给定稀疏度K。该方法的去噪效果会受到图像稀疏度的影响。另外,训练初始系数时用到的追踪类算法中通过向量内积值的大小评定图像分量间相关度的方法,因存在大值噪声点,容易造成假相关,从而影响去噪效果。提出基于差异系数的稀疏度自适应K-SVD去噪算法,通过引入差异系数来平衡因噪声点造成的假相关问题,同时使用相关度均值作为阈值来自适应地产生稀疏度K,避免因给定不恰当的稀疏度而影响去噪效果的问题。在USC标准库上的实验结果表明,所提算法在去噪效果方面有一定的优越性。
