With the rapid development of the Internet globally since the 21st century,the amount of data information has increased exponentially.Data helps improve people’s livelihood and working conditions,as well as learning ...With the rapid development of the Internet globally since the 21st century,the amount of data information has increased exponentially.Data helps improve people’s livelihood and working conditions,as well as learning efficiency.Therefore,data extraction,analysis,and processing have become a hot issue for people from all walks of life.Traditional recommendation algorithm still has some problems,such as inaccuracy,less diversity,and low performance.To solve these problems and improve the accuracy and variety of the recommendation algorithms,the research combines the convolutional neural networks(CNN)and the attention model to design a recommendation algorithm based on the neural network framework.Through the text convolutional network,the input layer in CNN has transformed into two channels:static ones and non-static ones.Meanwhile,the self-attention system focuses on the system so that data can be better processed and the accuracy of feature extraction becomes higher.The recommendation algorithm combines CNN and attention system and divides the embedding layer into user information feature embedding and data name feature extraction embedding.It obtains data name features through a convolution kernel.Finally,the top pooling layer obtains the length vector.The attention system layer obtains the characteristics of the data type.Experimental results show that the proposed recommendation algorithm that combines CNN and the attention system can perform better in data extraction than the traditional CNN algorithm and other recommendation algorithms that are popular at the present stage.The proposed algorithm shows excellent accuracy and robustness.展开更多
起落架刹车系统是飞机的重要组成部分,及时准确地诊断起落架刹车系统的故障,可以避免因故障导致的事故,提高飞机安全性。针对起落架刹车系统现有诊断算法识别精度较低和缺乏系统的参数优化等问题,提出了一种利用冠豪猪优化器(Crested Po...起落架刹车系统是飞机的重要组成部分,及时准确地诊断起落架刹车系统的故障,可以避免因故障导致的事故,提高飞机安全性。针对起落架刹车系统现有诊断算法识别精度较低和缺乏系统的参数优化等问题,提出了一种利用冠豪猪优化器(Crested Porcupine Optimizer,CPO)算法优化卷积神经网络融合长短期记忆网络(Convolutional Neural Network-Long Short Term Memory,CNN-LSTM)的飞机起落架刹车系统故障诊断方法。利用CPO的快速寻优能力,将找到的最优参数代入CNN-LSTM中重新构建模型,对起落架飞参数据进行训练分类并输出结果。诊断实验中,以某型号飞机起落架刹车系统真实飞参数据为输入,对起落架刹车系统的常见故障模式进行分类。实验结果表明,所提出的故障诊断方法有较好的故障诊断性能和实际的应用价值。展开更多
合理规划好集中供热一次网的供热负荷,对满足热用户的舒适度和减少能源消耗有着重要意义。为此提出一种改进金豺算法(improved golden jackal optimization,IGJO)优化的CNN-BiLSTM热负荷预测模型。综合考虑一次网各项参数和天气因素的影...合理规划好集中供热一次网的供热负荷,对满足热用户的舒适度和减少能源消耗有着重要意义。为此提出一种改进金豺算法(improved golden jackal optimization,IGJO)优化的CNN-BiLSTM热负荷预测模型。综合考虑一次网各项参数和天气因素的影响,将热负荷历史值和一次网供水温度、供水流量、供水压力、外界天气温度组成CNN-BiLSTM网络的输入,利用CNN-BiLSTM网络提取输入数据的空间特征和时间特征。同时,通过Circle混沌映射、螺旋波动搜索、自适应t变异策略改进GJO,得到的IGJO有效解决了GJO全局搜索能力弱和收敛精度不高的问题,具有高效的寻优效果,然后利用IGJO寻优CNN-BiLSTM网络的超参数,解决了因CNN-BiLSTM网络的超参数选取不当而影响热负荷预测结果的问题。最后利用吉林延边某换热站2021年1月到3月供热负荷数据进行模型测试。结果表明,所提IGJO-CNN-BiLSTM预测结果的MAE、MAPE、RMSE和NSE分别为0.005 MW、0.33%、0.008 MW和0.97,相比LSTM、CNN-LSTM等模型,具有更优的预测精度。展开更多
滚动轴承作为机械设备的重要部件,对其进行剩余使用寿命预测在企业的生产过程中变得越来越重要。目前,虽然主流的卷积神经网络(convolutional neural network, CNN)可以自动地从轴承的振动信号中提取特征,却不能给特征分配不同的权重来...滚动轴承作为机械设备的重要部件,对其进行剩余使用寿命预测在企业的生产过程中变得越来越重要。目前,虽然主流的卷积神经网络(convolutional neural network, CNN)可以自动地从轴承的振动信号中提取特征,却不能给特征分配不同的权重来提高模型对重要特征的关注程度,对于长时间序列容易丢失重要信息。另外,神经网络中隐藏层神经元个数、学习率以及正则化参数等超参数还需要依靠人工经验设置。为了解决上述问题,提出基于灰狼优化(grey wolf optimizer, GWO)算法、优化集合CNN、双向长短期记忆(bidirectional long short term memory, BiLSTM)网络和注意力机制(Attention)轴承剩余使用寿命预测方法。首先,从原始振动信号中提取时域、频域以及时频域特征指标构建可选特征集;然后,通过构建考虑特征相关性、鲁棒性和单调性的综合评价指标筛选出高于设定阈值的轴承退化敏感特征集,作为预测模型的输入;最后,将预测值和真实值的均方误差作为GWO算法的适应度函数,优化预测模型获得最优隐藏层神经元个数、学习率和正则化参数,利用优化后模型进行剩余使用寿命预测,并在公开数据集上进行验证。结果表明,所提方法可在非经验指导下获得最优的超参数组合,优化后的预测模型与未进行优化模型相比,平均绝对误差与均方根误差分别降低了28.8%和24.3%。展开更多
文摘With the rapid development of the Internet globally since the 21st century,the amount of data information has increased exponentially.Data helps improve people’s livelihood and working conditions,as well as learning efficiency.Therefore,data extraction,analysis,and processing have become a hot issue for people from all walks of life.Traditional recommendation algorithm still has some problems,such as inaccuracy,less diversity,and low performance.To solve these problems and improve the accuracy and variety of the recommendation algorithms,the research combines the convolutional neural networks(CNN)and the attention model to design a recommendation algorithm based on the neural network framework.Through the text convolutional network,the input layer in CNN has transformed into two channels:static ones and non-static ones.Meanwhile,the self-attention system focuses on the system so that data can be better processed and the accuracy of feature extraction becomes higher.The recommendation algorithm combines CNN and attention system and divides the embedding layer into user information feature embedding and data name feature extraction embedding.It obtains data name features through a convolution kernel.Finally,the top pooling layer obtains the length vector.The attention system layer obtains the characteristics of the data type.Experimental results show that the proposed recommendation algorithm that combines CNN and the attention system can perform better in data extraction than the traditional CNN algorithm and other recommendation algorithms that are popular at the present stage.The proposed algorithm shows excellent accuracy and robustness.
文摘起落架刹车系统是飞机的重要组成部分,及时准确地诊断起落架刹车系统的故障,可以避免因故障导致的事故,提高飞机安全性。针对起落架刹车系统现有诊断算法识别精度较低和缺乏系统的参数优化等问题,提出了一种利用冠豪猪优化器(Crested Porcupine Optimizer,CPO)算法优化卷积神经网络融合长短期记忆网络(Convolutional Neural Network-Long Short Term Memory,CNN-LSTM)的飞机起落架刹车系统故障诊断方法。利用CPO的快速寻优能力,将找到的最优参数代入CNN-LSTM中重新构建模型,对起落架飞参数据进行训练分类并输出结果。诊断实验中,以某型号飞机起落架刹车系统真实飞参数据为输入,对起落架刹车系统的常见故障模式进行分类。实验结果表明,所提出的故障诊断方法有较好的故障诊断性能和实际的应用价值。
文摘滚动轴承作为机械设备的重要部件,对其进行剩余使用寿命预测在企业的生产过程中变得越来越重要。目前,虽然主流的卷积神经网络(convolutional neural network, CNN)可以自动地从轴承的振动信号中提取特征,却不能给特征分配不同的权重来提高模型对重要特征的关注程度,对于长时间序列容易丢失重要信息。另外,神经网络中隐藏层神经元个数、学习率以及正则化参数等超参数还需要依靠人工经验设置。为了解决上述问题,提出基于灰狼优化(grey wolf optimizer, GWO)算法、优化集合CNN、双向长短期记忆(bidirectional long short term memory, BiLSTM)网络和注意力机制(Attention)轴承剩余使用寿命预测方法。首先,从原始振动信号中提取时域、频域以及时频域特征指标构建可选特征集;然后,通过构建考虑特征相关性、鲁棒性和单调性的综合评价指标筛选出高于设定阈值的轴承退化敏感特征集,作为预测模型的输入;最后,将预测值和真实值的均方误差作为GWO算法的适应度函数,优化预测模型获得最优隐藏层神经元个数、学习率和正则化参数,利用优化后模型进行剩余使用寿命预测,并在公开数据集上进行验证。结果表明,所提方法可在非经验指导下获得最优的超参数组合,优化后的预测模型与未进行优化模型相比,平均绝对误差与均方根误差分别降低了28.8%和24.3%。
