Flatness is one of the most important criterion factors to evaluate the quality of the steel strip. To improve the strip＇ s flatness quality, the most frequently used methodology is to employ the closed-loop automati...Flatness is one of the most important criterion factors to evaluate the quality of the steel strip. To improve the strip＇ s flatness quality, the most frequently used methodology is to employ the closed-loop automatic shape control system. However, in the shape control system, the shape-meter is always installed at the down way of the exit of the cold rolling mill and can not sense the changes of the strip flatness in the rolling gap directly. This kind of installation results in the delay of the feedback in the control system. Therefore, the stability and response performance of the system are strongly affected by the delay. At present, there is still no mature way to design controllers for systems with time delay. Although the conventional PID controller used in most practical applications has the capability to compensate the delay, the effect of the compensation is limited, especially for the systems with long time delay. Smith predictor, as a compensator for solving this problem, is now widely used in industry systems. However, the request of highly precise model of the system and the poor adaptive performance to the changes of related parameters limit the application of the Smith predictor in practice. In order to overcome the drawbacks of the Smith predictor, a new Smith predictor based on single neural network PID （SNN-PID） is proposed. Because the single neural network is employed into the Smith predictor to improve the controller＇s self-adaptability, the adaptive capability to the varying parameters of the system is improved. Meanwhile, for the purpose of solving the problems such as time-consuming and complicated calculation of the neural networks in real time, the learning coefficient of neural network is divided into several stages as usually done in expert control system. Therefore, the control system can obtain fast response due to the improved calculation speed of the neural networks. In order to validate the performance of the proposed controller, the experiment is conducted on the shape control system in a 300 mm four-high reversing cold rolling mill. The experimental results show that the SNN-PID with Smith predictor controller can effectively compensate the delay effects and achieve better control performance than the conventional PID controller.展开更多
Enterprise Information System management has become an increasingly vital factor for many firms. Several organizations have encountered problems when attempting to evaluate organizational performance. Measurement of p...Enterprise Information System management has become an increasingly vital factor for many firms. Several organizations have encountered problems when attempting to evaluate organizational performance. Measurement of performance metrics is a key challenge for a huge number of firms. In order to preserve relevance and adaptability in competitive markets, it has become essential to respond proactively to complex events through informed decision-making that is supported by technology. Therefore, the objective of this study was to apply neural networks to the modeling, simulation, and forecasting of the effects of the performance indicators of Enterprise Information Systems on the achievement of corporate objectives and value creation. A set of quantifiable and sizeable conditionally independent associations were derived using a simplified joint probability distribution technique. Bayesian Neural Networks were utilized to describe the link between random variables (features) and to concisely and easily specify the joint probability distribution. The research demonstrated that Bayesian networks could effectively explore complex logical linkages by employing probability to represent uncertainty and probabilistic rules;and by applying impact models from Bayesian taxonomies to achieve learning and reasoning processes.展开更多
A novel sequential neural network learning algorithm for function approximation is presented. The multi-step-ahead output predictor of the stochastic time series is introduced to the growing and pruning network for co...A novel sequential neural network learning algorithm for function approximation is presented. The multi-step-ahead output predictor of the stochastic time series is introduced to the growing and pruning network for constructing network structure. And the network parameters are adjusted by the proportional differential filter （PDF） rather than EKF when the network growing criteria are not met. Experimental results show that the proposed algorithm can obtain a more compact network along with a smaller error in mean square sense than other typical sequential learning algorithms.展开更多
Convolutional neural networks(CNNs) have been widely studied and found to obtain favorable results in statistical downscaling to derive high-resolution climate variables from large-scale coarse general circulation mod...Convolutional neural networks(CNNs) have been widely studied and found to obtain favorable results in statistical downscaling to derive high-resolution climate variables from large-scale coarse general circulation models(GCMs).However, there is a lack of research exploring the predictor selection for CNN modeling. This paper presents an effective and efficient greedy elimination algorithm to address this problem. The algorithm has three main steps: predictor importance attribution, predictor removal, and CNN retraining, which are performed sequentially and iteratively. The importance of individual predictors is measured by a gradient-based importance metric computed by a CNN backpropagation technique, which was initially proposed for CNN interpretation. The algorithm is tested on the CNN-based statistical downscaling of monthly precipitation with 20 candidate predictors and compared with a correlation analysisbased approach. Linear models are implemented as benchmarks. The experiments illustrate that the predictor selection solution can reduce the number of input predictors by more than half, improve the accuracy of both linear and CNN models,and outperform the correlation analysis method. Although the RMSE(root-mean-square error) is reduced by only 0.8%,only 9 out of 20 predictors are used to build the CNN, and the FLOPs(Floating Point Operations) decrease by 20.4%. The results imply that the algorithm can find subset predictors that correlate more to the monthly precipitation of the target area and seasons in a nonlinear way. It is worth mentioning that the algorithm is compatible with other CNN models with stacked variables as input and has the potential for nonlinear correlation predictor selection.展开更多
基于会话的推荐旨在利用短时匿名会话预测用户行为.现有结合图神经网络与对比学习的会话推荐模型大多采用联合优化交叉熵损失与对比学习损失的方法,但二者所起作用相似,同时需要构建大量复杂的正负样本,为模型带来负担.此外,简单的线性...基于会话的推荐旨在利用短时匿名会话预测用户行为.现有结合图神经网络与对比学习的会话推荐模型大多采用联合优化交叉熵损失与对比学习损失的方法,但二者所起作用相似,同时需要构建大量复杂的正负样本,为模型带来负担.此外,简单的线性预测器不能较好地预测带有用户随机行为的数据.针对上述问题,文中提出结合自对比图神经网络与双预测器的会话推荐模型(Session-Based Recommendation Model with Self Contrastive Graph Neural Network and Dual Predictor,SCGNN).首先,使用双视图建模原始会话,采用改进的图神经网络学习物品嵌入与会话嵌入,并通过自对比学习优化物品表示.然后,提出用户行为感知因子,应对用户随机行为带来的影响.最后,采用决策森林预测器与线性预测器对物品进行预测,并提出软标签生成策略,通过协同过滤与当前会话类似的历史会话以辅助预测.在Tmall、Diginetica、Nowplaying数据集上的实验表明文中模型的有效性.展开更多
An on-line training functional-link neural network predictor/controller fordynamic positioning of water surface structures is described in this paper. The on-line trainingneural network predictor acquires the knowledg...An on-line training functional-link neural network predictor/controller fordynamic positioning of water surface structures is described in this paper. The on-line trainingneural network predictor acquires the knowledge about the system using a small number of samples ofthe latest system status measured on board of the structure. The trained function-link neuralnetwork is used with an optimal controller to control the output of the system. The accuracy androbustness of the on-line training predictor are demonstrated through the numerical simulations oftwo ship maneuvers. The on-line training neural network predictor/controller is applied to thedynamic positioning (station-keeping) of a ship in a uniform current with and without externalenvironmental disturbances. The results of the numerical simulations are very satisfactory.展开更多
基金supported by National Natural Science Foundation of China (Grant No. 604740044)Hebei Provincial Natural Science Foundation of China (Grant No. E2004000221)
文摘Flatness is one of the most important criterion factors to evaluate the quality of the steel strip. To improve the strip＇ s flatness quality, the most frequently used methodology is to employ the closed-loop automatic shape control system. However, in the shape control system, the shape-meter is always installed at the down way of the exit of the cold rolling mill and can not sense the changes of the strip flatness in the rolling gap directly. This kind of installation results in the delay of the feedback in the control system. Therefore, the stability and response performance of the system are strongly affected by the delay. At present, there is still no mature way to design controllers for systems with time delay. Although the conventional PID controller used in most practical applications has the capability to compensate the delay, the effect of the compensation is limited, especially for the systems with long time delay. Smith predictor, as a compensator for solving this problem, is now widely used in industry systems. However, the request of highly precise model of the system and the poor adaptive performance to the changes of related parameters limit the application of the Smith predictor in practice. In order to overcome the drawbacks of the Smith predictor, a new Smith predictor based on single neural network PID （SNN-PID） is proposed. Because the single neural network is employed into the Smith predictor to improve the controller＇s self-adaptability, the adaptive capability to the varying parameters of the system is improved. Meanwhile, for the purpose of solving the problems such as time-consuming and complicated calculation of the neural networks in real time, the learning coefficient of neural network is divided into several stages as usually done in expert control system. Therefore, the control system can obtain fast response due to the improved calculation speed of the neural networks. In order to validate the performance of the proposed controller, the experiment is conducted on the shape control system in a 300 mm four-high reversing cold rolling mill. The experimental results show that the SNN-PID with Smith predictor controller can effectively compensate the delay effects and achieve better control performance than the conventional PID controller.
文摘Enterprise Information System management has become an increasingly vital factor for many firms. Several organizations have encountered problems when attempting to evaluate organizational performance. Measurement of performance metrics is a key challenge for a huge number of firms. In order to preserve relevance and adaptability in competitive markets, it has become essential to respond proactively to complex events through informed decision-making that is supported by technology. Therefore, the objective of this study was to apply neural networks to the modeling, simulation, and forecasting of the effects of the performance indicators of Enterprise Information Systems on the achievement of corporate objectives and value creation. A set of quantifiable and sizeable conditionally independent associations were derived using a simplified joint probability distribution technique. Bayesian Neural Networks were utilized to describe the link between random variables (features) and to concisely and easily specify the joint probability distribution. The research demonstrated that Bayesian networks could effectively explore complex logical linkages by employing probability to represent uncertainty and probabilistic rules;and by applying impact models from Bayesian taxonomies to achieve learning and reasoning processes.
基金Sponsored by the Ministerial Level Foundation(230032)
文摘A novel sequential neural network learning algorithm for function approximation is presented. The multi-step-ahead output predictor of the stochastic time series is introduced to the growing and pruning network for constructing network structure. And the network parameters are adjusted by the proportional differential filter （PDF） rather than EKF when the network growing criteria are not met. Experimental results show that the proposed algorithm can obtain a more compact network along with a smaller error in mean square sense than other typical sequential learning algorithms.
基金supported by the following grants: National Basic R&D Program of China (2018YFA0606203)Strategic Priority Research Program of Chinese Academy of Sciences (XDA23090102 and XDA20060501)+2 种基金Guangdong Major Project of Basic and Applied Basic Research (2020B0301030004)Special Fund of China Meteorological Administration for Innovation and Development (CXFZ2021J026)Special Fund for Forecasters of China Meteorological Administration (CMAYBY2020094)。
文摘Convolutional neural networks(CNNs) have been widely studied and found to obtain favorable results in statistical downscaling to derive high-resolution climate variables from large-scale coarse general circulation models(GCMs).However, there is a lack of research exploring the predictor selection for CNN modeling. This paper presents an effective and efficient greedy elimination algorithm to address this problem. The algorithm has three main steps: predictor importance attribution, predictor removal, and CNN retraining, which are performed sequentially and iteratively. The importance of individual predictors is measured by a gradient-based importance metric computed by a CNN backpropagation technique, which was initially proposed for CNN interpretation. The algorithm is tested on the CNN-based statistical downscaling of monthly precipitation with 20 candidate predictors and compared with a correlation analysisbased approach. Linear models are implemented as benchmarks. The experiments illustrate that the predictor selection solution can reduce the number of input predictors by more than half, improve the accuracy of both linear and CNN models,and outperform the correlation analysis method. Although the RMSE(root-mean-square error) is reduced by only 0.8%,only 9 out of 20 predictors are used to build the CNN, and the FLOPs(Floating Point Operations) decrease by 20.4%. The results imply that the algorithm can find subset predictors that correlate more to the monthly precipitation of the target area and seasons in a nonlinear way. It is worth mentioning that the algorithm is compatible with other CNN models with stacked variables as input and has the potential for nonlinear correlation predictor selection.
文摘基于会话的推荐旨在利用短时匿名会话预测用户行为.现有结合图神经网络与对比学习的会话推荐模型大多采用联合优化交叉熵损失与对比学习损失的方法,但二者所起作用相似,同时需要构建大量复杂的正负样本,为模型带来负担.此外,简单的线性预测器不能较好地预测带有用户随机行为的数据.针对上述问题,文中提出结合自对比图神经网络与双预测器的会话推荐模型(Session-Based Recommendation Model with Self Contrastive Graph Neural Network and Dual Predictor,SCGNN).首先,使用双视图建模原始会话,采用改进的图神经网络学习物品嵌入与会话嵌入,并通过自对比学习优化物品表示.然后,提出用户行为感知因子,应对用户随机行为带来的影响.最后,采用决策森林预测器与线性预测器对物品进行预测,并提出软标签生成策略,通过协同过滤与当前会话类似的历史会话以辅助预测.在Tmall、Diginetica、Nowplaying数据集上的实验表明文中模型的有效性.
文摘An on-line training functional-link neural network predictor/controller fordynamic positioning of water surface structures is described in this paper. The on-line trainingneural network predictor acquires the knowledge about the system using a small number of samples ofthe latest system status measured on board of the structure. The trained function-link neuralnetwork is used with an optimal controller to control the output of the system. The accuracy androbustness of the on-line training predictor are demonstrated through the numerical simulations oftwo ship maneuvers. The on-line training neural network predictor/controller is applied to thedynamic positioning (station-keeping) of a ship in a uniform current with and without externalenvironmental disturbances. The results of the numerical simulations are very satisfactory.
