In the non-linear microwave drying process, the incremental improved back-propagation （BP） neural network and response surface methodology （RSM） were used to build a predictive model of the combined effects of ind...In the non-linear microwave drying process, the incremental improved back-propagation （BP） neural network and response surface methodology （RSM） were used to build a predictive model of the combined effects of independent variables （the microwave power, the acting time and the rotational frequency） for microwave drying of selenium-rich slag. The optimum operating conditions obtained from the quadratic form of the RSM are： the microwave power of 14.97 kW, the acting time of 89.58 min, the rotational frequency of 10.94 Hz, and the temperature of 136.407 ℃. The relative dehydration rate of 97.1895% is obtained. Under the optimum operating conditions, the incremental improved BP neural network prediction model can predict the drying process results and different effects on the results of the independent variables. The verification experiments demonstrate the prediction accuracy of the network, and the mean squared error is 0.16. The optimized results indicate that RSM can optimize the experimental conditions within much more broad range by considering the combination of factors and the neural network model can predict the results effectively and provide the theoretical guidance for the follow-up production process.展开更多
Damage assessment of the wing under blast wave is essential to the vulnerability reduction design of aircraft. This paper introduces a critical relative distance prediction method of aircraft wing damage based on the ...Damage assessment of the wing under blast wave is essential to the vulnerability reduction design of aircraft. This paper introduces a critical relative distance prediction method of aircraft wing damage based on the back-propagation artificial neural network(BP-ANN), which is trained by finite element simulation results. Moreover, the finite element method(FEM) for wing blast damage simulation has been validated by ground explosion tests and further used for damage mode determination and damage characteristics analysis. The analysis results indicate that the wing is more likely to be damaged when the root is struck from vertical directions than others for a small charge. With the increase of TNT equivalent charge, the main damage mode of the wing gradually changes from the local skin tearing to overall structural deformation and the overpressure threshold of wing damage decreases rapidly. Compared to the FEM-based damage assessment, the BP-ANN-based method can predict the wing damage under a random blast wave with an average relative error of 4.78%. The proposed method and conclusions can be used as a reference for damage assessment under blast wave and low-vulnerability design of aircraft structures.展开更多
变压器套管作为设备重要的绝缘部件,其绝缘性能直接影响着设备的安全运行。为诊断变压器套管绝缘状态,改善变压器套管油中溶解气体的小样本不平衡数据对变压器套管故障诊断结果的影响,使用粒子群优化结合反向传播神经网络(particle swar...变压器套管作为设备重要的绝缘部件,其绝缘性能直接影响着设备的安全运行。为诊断变压器套管绝缘状态,改善变压器套管油中溶解气体的小样本不平衡数据对变压器套管故障诊断结果的影响,使用粒子群优化结合反向传播神经网络(particle swarm optimization combined with back propagation neural network,PSO-BPNN)和自适应综合过采样(adaptive synthetic sampling,ADASYN)算法对变压器套管进行故障诊断。首先收集变压器套管的历史故障数据,建立具有明确故障类别的变压器套管油中溶解气体样本集,并通过ADASYN算法对原始数据中的少数类样本进行合成,得到平衡后的故障数据,然后将平衡后的油中溶解气体作为模型输入,故障状态作为标签输出,通过PSO-BPNN模型对变压器套管进行诊断,最后在原始样本集下使用反向传播神经网络(back propagation neural network,BPNN)、遗传结合反向传播神经网络(genetic combined with back propagation neural network,G-BPNN)算法、布谷鸟搜索结合反向传播神经网络(cuckoo search combined with back propagation neural network,CS-BPNN)算法以及PSO-BPNN模型对套管进行诊断。结果表明,针对变压器油纸套管绝缘状态进行故障诊断的多个模型中,基于ADASYN平衡数据后的PSO-BPNN模型和其他模型相比准确度最高,能有效减小小样本不平衡数据对诊断结果的影响,为判断变压器油纸套管绝缘性能提供了有效方法。展开更多
基金Project(50734007) supported by the National Natural Science Foundation of China
文摘In the non-linear microwave drying process, the incremental improved back-propagation （BP） neural network and response surface methodology （RSM） were used to build a predictive model of the combined effects of independent variables （the microwave power, the acting time and the rotational frequency） for microwave drying of selenium-rich slag. The optimum operating conditions obtained from the quadratic form of the RSM are： the microwave power of 14.97 kW, the acting time of 89.58 min, the rotational frequency of 10.94 Hz, and the temperature of 136.407 ℃. The relative dehydration rate of 97.1895% is obtained. Under the optimum operating conditions, the incremental improved BP neural network prediction model can predict the drying process results and different effects on the results of the independent variables. The verification experiments demonstrate the prediction accuracy of the network, and the mean squared error is 0.16. The optimized results indicate that RSM can optimize the experimental conditions within much more broad range by considering the combination of factors and the neural network model can predict the results effectively and provide the theoretical guidance for the follow-up production process.
基金supported by the Natural Science Foundation of Shaanxi Province (Grant No. 2020JQ-122)the Fund support of Science and Technology on Transient Impact Laboratory。
文摘Damage assessment of the wing under blast wave is essential to the vulnerability reduction design of aircraft. This paper introduces a critical relative distance prediction method of aircraft wing damage based on the back-propagation artificial neural network(BP-ANN), which is trained by finite element simulation results. Moreover, the finite element method(FEM) for wing blast damage simulation has been validated by ground explosion tests and further used for damage mode determination and damage characteristics analysis. The analysis results indicate that the wing is more likely to be damaged when the root is struck from vertical directions than others for a small charge. With the increase of TNT equivalent charge, the main damage mode of the wing gradually changes from the local skin tearing to overall structural deformation and the overpressure threshold of wing damage decreases rapidly. Compared to the FEM-based damage assessment, the BP-ANN-based method can predict the wing damage under a random blast wave with an average relative error of 4.78%. The proposed method and conclusions can be used as a reference for damage assessment under blast wave and low-vulnerability design of aircraft structures.
文摘变压器套管作为设备重要的绝缘部件,其绝缘性能直接影响着设备的安全运行。为诊断变压器套管绝缘状态,改善变压器套管油中溶解气体的小样本不平衡数据对变压器套管故障诊断结果的影响,使用粒子群优化结合反向传播神经网络(particle swarm optimization combined with back propagation neural network,PSO-BPNN)和自适应综合过采样(adaptive synthetic sampling,ADASYN)算法对变压器套管进行故障诊断。首先收集变压器套管的历史故障数据,建立具有明确故障类别的变压器套管油中溶解气体样本集,并通过ADASYN算法对原始数据中的少数类样本进行合成,得到平衡后的故障数据,然后将平衡后的油中溶解气体作为模型输入,故障状态作为标签输出,通过PSO-BPNN模型对变压器套管进行诊断,最后在原始样本集下使用反向传播神经网络(back propagation neural network,BPNN)、遗传结合反向传播神经网络(genetic combined with back propagation neural network,G-BPNN)算法、布谷鸟搜索结合反向传播神经网络(cuckoo search combined with back propagation neural network,CS-BPNN)算法以及PSO-BPNN模型对套管进行诊断。结果表明,针对变压器油纸套管绝缘状态进行故障诊断的多个模型中,基于ADASYN平衡数据后的PSO-BPNN模型和其他模型相比准确度最高,能有效减小小样本不平衡数据对诊断结果的影响,为判断变压器油纸套管绝缘性能提供了有效方法。
