To solve the problem of convergence to a local optimum in the multi-layer feedforward neural net-work, a new disturbance gradient algorithm is proposed. Through introducing random disturbance into the training process...To solve the problem of convergence to a local optimum in the multi-layer feedforward neural net-work, a new disturbance gradient algorithm is proposed. Through introducing random disturbance into the training process, the algorithm can avoid being trapped into the local optimum. The random disturbance obeys the Boltzmann distribution. The convergence of the algorithm to the global optimum is statistically guaranteed. The application of the algorithm in RoboCup, which is a complex multi-agent system, is dis-cussed. Experiment results illustrate the learning efficiency and generalization ability of the proposed al-gorithm.展开更多
Single gimbal control moment gyroscope(SGCMG)with high precision and fast response is an important attitude control system for high precision docking,rapid maneuvering navigation and guidance system in the aerospace f...Single gimbal control moment gyroscope(SGCMG)with high precision and fast response is an important attitude control system for high precision docking,rapid maneuvering navigation and guidance system in the aerospace field.In this paper,considering the influence of multi-source disturbance,a data-based feedback relearning(FR)algorithm is designed for the robust control of SGCMG gimbal servo system.Based on adaptive dynamic programming and least-square principle,the FR algorithm is used to obtain the servo control strategy by collecting the online operation data of SGCMG system.This is a model-free learning strategy in which no prior knowledge of the SGCMG model is required.Then,combining the reinforcement learning mechanism,the servo control strategy is interacted with system dynamic of SGCMG.The adaptive evaluation and improvement of servo control strategy against the multi-source disturbance are realized.Meanwhile,a data redistribution method based on experience replay is designed to reduce data correlation to improve algorithm stability and data utilization efficiency.Finally,by comparing with other methods on the simulation model of SGCMG,the effectiveness of the proposed servo control strategy is verified.展开更多
Bilingual children＇ s word awareness can reflect the impact of bilingualism on language cognition from the aspect of psycholinguistics. The current studies on bilingual children＇s word awareness both at home and abr...Bilingual children＇ s word awareness can reflect the impact of bilingualism on language cognition from the aspect of psycholinguistics. The current studies on bilingual children＇s word awareness both at home and abroad show that there exist quite opposite points of views： bilingual disadvantage and bilingual advantage. The interpretation mechanisms of interference effect, word frequency, and mutual exclusivity constraint are used to support the bilingual disadvantage; while the interpretation mechanisms of bilingual advantage include sound coding, short-term memory, and inhibitory control. In effect, there is no negative impact of bilingualism on children＇s word awareness, and the so-called negative effects only exist on the theoretical aspect of research. The development of children＇s word awareness is influenced by many factors including age of acquisition, learning environment, and bilingual proficiency, etc.展开更多
文摘To solve the problem of convergence to a local optimum in the multi-layer feedforward neural net-work, a new disturbance gradient algorithm is proposed. Through introducing random disturbance into the training process, the algorithm can avoid being trapped into the local optimum. The random disturbance obeys the Boltzmann distribution. The convergence of the algorithm to the global optimum is statistically guaranteed. The application of the algorithm in RoboCup, which is a complex multi-agent system, is dis-cussed. Experiment results illustrate the learning efficiency and generalization ability of the proposed al-gorithm.
基金This work was supported by the National Natural Science Foundation of China(No.62022061)Tianjin Natural Science Foundation(No.20JCYBJC00880)Beijing Key Laboratory Open Fund of Long-Life Technology of Precise Rotation and Transmission Mechanisms.
文摘Single gimbal control moment gyroscope(SGCMG)with high precision and fast response is an important attitude control system for high precision docking,rapid maneuvering navigation and guidance system in the aerospace field.In this paper,considering the influence of multi-source disturbance,a data-based feedback relearning(FR)algorithm is designed for the robust control of SGCMG gimbal servo system.Based on adaptive dynamic programming and least-square principle,the FR algorithm is used to obtain the servo control strategy by collecting the online operation data of SGCMG system.This is a model-free learning strategy in which no prior knowledge of the SGCMG model is required.Then,combining the reinforcement learning mechanism,the servo control strategy is interacted with system dynamic of SGCMG.The adaptive evaluation and improvement of servo control strategy against the multi-source disturbance are realized.Meanwhile,a data redistribution method based on experience replay is designed to reduce data correlation to improve algorithm stability and data utilization efficiency.Finally,by comparing with other methods on the simulation model of SGCMG,the effectiveness of the proposed servo control strategy is verified.
基金Acknowledgements： This study was supported by National Social Science Foundation （grant number 14BYY060）, a China Postdoctoral Science Foundation （grant number 2012M520057）, and a Startup Fund for Advanced Talents of Nanjing Forestry University （grant number GXL022）.
文摘Bilingual children＇ s word awareness can reflect the impact of bilingualism on language cognition from the aspect of psycholinguistics. The current studies on bilingual children＇s word awareness both at home and abroad show that there exist quite opposite points of views： bilingual disadvantage and bilingual advantage. The interpretation mechanisms of interference effect, word frequency, and mutual exclusivity constraint are used to support the bilingual disadvantage; while the interpretation mechanisms of bilingual advantage include sound coding, short-term memory, and inhibitory control. In effect, there is no negative impact of bilingualism on children＇s word awareness, and the so-called negative effects only exist on the theoretical aspect of research. The development of children＇s word awareness is influenced by many factors including age of acquisition, learning environment, and bilingual proficiency, etc.
