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Deciphering environmental factors influencing phytoplankton community structure in a polluted urban river

Journal of Environmental Sciences 2025年第2期148卷 375-386页

作者： Xiaxia Li Kai Chen Chao Wang Tianyu Zhuo Hongtao Li Yong Wu Xiaohui Lei Ming Li Bin Chen Beibei Chai School of Water Conservancy and Hydroelectric Power Hebei University of EngineeringHandan 056038China Collaborative Innovation Center for intelligent Regulation and Comprehensive Management of Water Resources School of Water Conservancy and HydroelectricHebei University of EngineeringHandan 056038China Hebei key laboratory of intelligent Water Conservancy Hebei University of EngineeringHandan 056038China Tianjin Water Group Binhai Water Co. Ltd.Tianjin 300308China State key laboratory of Simulation and Regulation of Water Cycle in River Basin China Institute of Water Resources and Hydropower ResearchBeijing 100038China School of Architecture and Civil Engineering Xi’an University of Science and TechnologyXi’an 710054China Chengdu University of Technology Chengdu 610059China College of Natural Resources and Environment Northwest A&F UniversityYangling 712100China State key Joint laboratory of Environment Simulation and Pollution control School of EnvironmentBeijing Normal UniversityBeijing 100875China

Tuojiang River Basin is a first-class tributary of the upper reaches of the Yangtze River—which is the longest river in *** phytoplankton are sensitive indicators of trophic changes inwater bodies,characterizing phytoplankton communities and their growth influencing factors in polluted urban rivers can provide new ideas for pollution ***,we used direct microscopic count and environmental DNA(eDNA)metabarcoding methods to investigate phytoplankton community structure in Tuojiang River Basin(Chengdu,Sichuan Province,China).The association between phytoplankton community structure and water environmental factors was evaluated by Mantel *** environmental monitoring data were used to pinpoint major factors that influenced phytoplankton growth based on structural equation *** the phylum level,the dominant phytoplankton taxa identified by the conventional microscopic method mainly belonged to Bacillariophyta,Chlorophyta,and Cyanophyta,in contrast with Chlorophyta,Dinophyceae,and Bacillariophyta identified by eDNA ***α-diversity analysis,eDNA metabarcoding detected greater species diversity and achieved higher precision than the microscopic *** growth was largely limited by phosphorus based on the nitrogen-to-phosphorus ratios>16:1 in all water *** analysis and structural equation modeling also confirmed that the nitrogen-to-phosphorus ratio was the principal factor influencing phytoplankton *** results could be useful for implementing comprehensive management of the river basin *** is recommended to control the discharge of point-and surface-source pollutants and the concentration of dissolved oxygen in areas with excessive nutrients(e.g.,Jianyang-Ziyang).Algae monitoring techniques and removal strategies should be improved in 201 Hospital,Hongrihe Bridge and Colmar Town areas.

关键词： Environmental DNA Microscopic count Phytoplankton growth Structural equation modeling Tuojiang River Basin

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Event-triggered attitude tracking for rigid spacecraft

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Science China(Information Sciences) 2019年第12期62卷 178-193页

作者： Deheng CAI Hengguang ZOU Junzheng WANG Yuan HUANG Dawei SHI State key laboratory of intelligent control and decision of complex systems School of AutomationBeijing Institute of Technology China Academy of Space Technology

This study aims to investigate the problem of attitude control for a spacecraft with inertial uncertainties, external disturbances, and communication restrictions. An event-triggered active disturbance rejection control approach is proposed for attitude tracking of the spacecraft. An event-triggered mechanism is introduced together with an extended state observer to jointly monitor the system states and total disturbances. The observation error is proved to be uniformly bounded. Based on the proposed control scheme,the integrated tracking system is shown to be asymptotically stable, implying successful attitude tracking of the spacecraft for the desired motion. Numerical results illustrate the effectiveness of the control strategy in achieving satisfactory tracking performance with a reduced data-transmission cost.

关键词： spacecraft attitude tracking active disturbance rejection control event-triggered control extended state observer

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On Event-triggered Adaptive Robust control 36

On Event-triggered Adaptive Robust Control

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第36届中国控制会议

作者： Yuan Huang Junzheng Wang Dawei Shi State key laboratory of intelligent control and decision of complex systems

ISBN: (纸本)9781538629185

In this work,an event-triggered adaptive robust controller（ET-ARC） design is considered for a continuous-time nonlinear system combined with structural uncertainties and parameter *** the event-trigger scheme,the controller only can obtain the sampled date of the output measurement at some certain instants determined by the designed triggering condition and therefore the performance of the ET-ARC depends on the triggering condition ***,in this work,for the adaptive robust control scheme,an event-triggered transmission strategy is proposed,which relies on the output measurement of the nonlinear ***,based on this strategy,the design idea of the adaptive robust controller is presented such that the tracking performance is ***,based on a more general assumption,we provide a possible formation of control signal which satisfies the requirement proposed.

关键词： Adaptive robust control event-triggered transmission parameter estimation

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Fault Tolerant control for a Class of Nonlinear System based on Active Disturbance Rejection control and RBF Neural Networks 36

Fault Tolerant Control for a Class of Nonlinear System based...

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第36届中国控制会议

作者： Lushan Zhou Liling Ma Junzheng Wang State key laboratory of intelligent control and decision of complex systems

ISBN: (纸本)9781538629185

In this paper,a fault tolerant control method based on active disturbance rejection control（ADRC） and radial basis function neural network（RBFNN） is proposed for a class of multi-input-multi-output nonlinear system with actuator faults,components faults and sensor *** proposed method does not rely on the plant *** regarding the faults and plant uncertainties as the disturbance,through the observation of extended state observer and the compensation of feedback control signal,this method achieves the fault tolerance control of the plant with component fault and actuator *** sensor faults,in this work,radial basis function neural network is applied to estimate the real output of the *** this output estimation is utilized by active disturbance rejection control to achieve the fault tolerance of ***,the effectiveness of the proposed method is validated by the simulation results of the three-tank system.

关键词： Fault tolerant control active disturbance rejection control radial basis function neural network

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Adaptive robust control for four-motor driving servo system with uncertain nonlinearities

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control Theory and Technology 2017年第1期15卷 45-57页

作者： Wei ZHAO Xuemei REN key laboratory of intelligent control and decision of complex systems School of Automation Beijing Institute of Technology Beijing 100081 China

A novel adaptive robust control （ARC） is presented for the four-motor driving servo systems with the uncertain nonlinearities and actuation failures, such that the load tracking control is achieved with the proximate optimal-time. By applying the proposed scheme, several control objectives are achieved. First, the nonlinear synchronization algorithm is presented to maintain the velocity synchronization of each motor, which provides fast convergence without chatting. Moreover, the time-varying bias torque is applied to eliminate the effect of backlash and reduce the waste of energy. Then, the ARC is designed to achieve the proximate optimal-time output tracking with the transient performance in L2 norm, where the friction and actuation failures are addressed by the adaptive scheme based on the norm estimation of unknown parameter vector. Finally, the extensive simulated and experimental results validate the effectiveness of the proposed method.

关键词： Four-motor driving servo systems adaptive robust control velocity synchronization control friction backlash,actuation failures

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Deep reinforcement learning for optimal denial-of-service attacks scheduling

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Science China(Information Sciences) 2022年第6期65卷 98-106页

作者： Fangyuan HOU Jian SUN Qiuling YANG Zhonghua PANG State key laboratory of intelligent control and decision of complex systems Beijing Institute of Technology key laboratory of Fieldbus Technology and Automation of Beijing North China University of Technology

We consider an optimal denial-of-service(DoS) attack scheduling problem of N independent linear time-invariant processes, where sensors have limited computational capability. Sensors transmit measurements to the remote estimator via a communication channel that is exposed to DoS attackers. However,due to limited energy, an attacker can only attack a subset of sensors at each time step. To maximally degrade the estimation performance, a DoS attacker needs to determine which sensors to attack at each time step. In this context, a deep reinforcement learning(DRL) algorithm, which combines Q-learning with a deep neural network, is introduced to solve the Markov decision process(MDP). The DoS attack scheduling optimization problem is formulated as an MDP that is solved by the DRL algorithm. A numerical example is provided to illustrate the efficiency of the optimal DoS attack scheduling scheme using the DRL algorithm.

关键词： optimal denial-of-service attack scheduling optimization limited energy deep reinforcement learning

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A data-driven rolling optimization method for trajectory tracking error prediction of CNC machine tools

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Science China(Technological Sciences) 2025年第1期68卷 270-285页

作者： Yinxin GUAN Jixiang YANG Shizhong TAN Han DING School of Mechanical Science and Engineering State Key Laboratory of Intelligent Manufacturing Equipment and TechnologyHuazhong University of Science and TechnologyWuhan 430074China

The dynamic performance of the feed-drive system in CNC machine tools directly influences the accuracy of machined *** enhance the motion control performance of CNC machine tools,a high-precision model of the feed-drive system is ***,current modeling methods for feed-drive systems seldom consider time-varying factors such as loads,wear,and *** a result,the model accuracy degrades when the system characteristics are affected by these time-varying *** this paper,a rolling optimization method with partial weights frozen is developed to realize quick iterative learning of a data-driven model for a feed drive system with time-varying characteristics using a small amount of ***,the long short-term memory fully connected(LSTM-FC)network is built and divided into feature extraction and output fitting parts based on their ***,a weight freezing-based rolling optimization method is *** weights in the feature extraction part are frozen,which preserves the learned common knowledge and patterns by solidifying the way that high-dimensional features are extracted from the *** adjusting the weights in the output fitting part,the extracted highdimensional features are remapped to the new data distribution changed by time-varying ***,the performance of the developed rolling optimization method is confirmed by *** results show that the proposed rolling optimization method reduces the maximum prediction errors by 49.5%and the total training time by 96.3%compared with existing methods,which demonstrates that the proposed method can restore model accuracy when the system characteristics change due to timevarying factors,and significantly accelerate the optimization process by rolling optimization.

关键词： rolling optimization feed-drive system data-driven time-varying machine tool

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Characteristics of Transition Layer at Soft Metal-Substrate Interface for Metal Seal

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稀有金属材料与工程 2025年第1期54卷 1-9页

作者： Zhang Dawei Zhang Xuekai Cao Zixuan Ge Ziyi Lv Shichang Li Zhijun Zhao Shengdun Hu Yanghu Xi'an key laboratory of intelligent Equipment and control School of Mechanical EngineeringXi'an Jiaotong UniversityXi'an 710049China Xi'an Aerospace Propulsion Institute Xi'an 710100China Light Alloy Research Institute Central South UniversityChangsha 410083China National key laboratory of Metal Forming Technology and Heavy Equipment Xi'an 710018China

The pressure-actuated metal seal with soft metal coating has been widely used in complex working conditions such as high temperature,low temperature and high *** investigation of the characteristics and binding strength of the transition layer between the soft metal coating and the superalloy substrate is important to improve the sealing performance and to model and simplify the working through-process of metal *** distribution characteristics of elements at soft metal-substrate interface and the binding strength between coating and substrate under different thicknesses and material combinations of coating layer were studied by experimental *** results indicate that the thickness of soft metal coating has little influence on the interface morphology of GH4169-Cu,GH4169-Ag and Cu-Ag,but has an influence on the thickness of transition layer between different metals,while this influence is weakened with increasing the coating thickness,and the thickness of transition layer is about 2μm when the coating thickness is more than 30μ*** cross-cut test shows that the Cu,Ag and Cu-Ag coatings are all well combined with nickel-based superalloy GH4169 *** materials of soft metal,*** coating materials,have significant influence on the characteristic of transition layer and the surface characteristics of coating after cross-cut test.

关键词： pressure-actuated metal seal nickel-based superalloy copper coating silver coating element transition layer

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Sequential fusion estimation for multisensor systems with non-Gaussian noises

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Science China(Information Sciences) 2020年第12期63卷 153-165页

作者： Liping YAN Chenying DI Q.M.Jonathan WU Yuanqing XIA key laboratory of intelligent control and decision of complex systems School of AutomationBeijing Institute of Technology Department of Electrical and Computer Engineering University of Windsor

The sequential fusion estimation for multisensor systems disturbed by non-Gaussian but heavytailed noises is studied in this paper. Based on multivariate t-distribution and the approximate t-filter,the sequential fusion algorithm is presented. The performance of the proposed algorithm is analyzed and compared with the t-filter-based centralized batch fusion and the Gaussian Kalman filter-based optimal centralized fusion. Theoretical analysis and exhaustive experimental analysis show that the proposed algorithm is effective. As the generalization of the classical Gaussian Kalman filter-based optimal sequential fusion algorithm, the presented algorithm is shown to be superior to the Gaussian Kalman filter-based optimal centralized batch fusion and the optimal sequential fusion in estimation of dynamic systems with non-Gaussian noises.

关键词： state estimation sequential fusion non-Gaussian disturbance heavy-tailed noise multivariate t-distribution

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Application of fuzzy cognitive map in information intelligent push

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Journal of Beijing Institute of Technology 2015年第4期24卷 553-557页

作者：张佳徐胜利邓方 School of Automation Beijing Institute of Technology key laboratory of intelligent control and decision of complex systems

Since computer system functions are becoming increasingly complex, the user has to spend much more time on the process of seeking information, instead of utilizing the required infor- mation. Information intelligent push technology could replace the traditional method to speed up the information retrieval process. The fuzzy cognitive map has strong knowledge representation ability and reasoning capability. Information intelligent push with the basis on fuzzy cognitive map could ab- stract the computer user＇ s operations to a fuzzy cognitive map, and infer the user＇ s operating inten- tions. The reasoning results will be translated into operational events, and drive the computer system to push appropriate information to the user.

关键词： fuzzy cognitive map artificial intelligence information intelligent push

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