检索结果-南通市图书馆

systems science in the new era: intelligent systems and big data

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

science China(Information sciences) 2024年第3期67卷 308-310页

作者： Wenwu YU Duxin CHEN Hongzhe LIU He WANG Jinde CAO Zengru DI Xiaojun DUAN Bin JIA Xiaodong DING Yiguang HONG School of Mathematics Southeast University Purple Mountain Laboratories International Academic center of complex systems Beijing Normal University College of science National University of Defense Technology School of systems science Beijing Jiaotong University Business School University of Shanghai for Science and Technology Department of Control science and Engineering Tongji University

This study introduces the emergence, research challenges,and future development of intelligent systems and big data(ISBD) and discusses the significance of ISBD to systems science. To this end, an overview of systems science is first presented, followed by the conclusion that the development of artificial intelligence(AI) has promoted the derivation and development of intelligent systems(ISs).

关键词：

Global Dynamics of a Delayed HIV-1 Infection Model with Cell-to-cell Transmission, Humoral Immunity and Immune Impairment

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Acta Mathematicae Applicatae Sinica 2024年

作者： Rui XU An-li XUE Chen-wei SONG complex systems research center Shanxi University School of Mathematical sciences Shanxi University

In this paper, an HIV-1 infection model with intracellular delay, humoral immunity and immune impairment is investigated, in which both virus-to-cell infection and cell-to-cell transmission are considered.The basic reproduction ratio is calculated and the existence of feasible equilibria is established. By analyzing the distributions of roots of the corresponding characteristic equations, the local asymptotic stability of each of feasible equilibria is established. With the help of appropriate Lyapunov functionals and LaSalle’s invariance principle, it is proved that if the basic reproduction ratio is less than unity, the infection-free equilibrium is globally asymptotically stable, and the virus is eventually eliminated; if the basic reproduction ratio is greater than unity, the chronic-infection equilibrium is globally asymptotically stable. Finally, numerical simulations are carried out to illustrate the effects of some parameters on HIV-1 infection dynamics.

关键词：

Enhanced adaptive nonlinear extended state observer for pure feedback systems with matched and mismatched disturbances

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Control Theory and Technology 2024年第2期22卷 254-268页

作者： Mahtab Delpasand Mohammad Farrokhi School of Electrical Engineering Iran University of Science and TechnologyTehran16846-13114Iran center of Excellence for Modelling and Control of complex systems Iran University of Science and TechnologyTehran16846-13114Iran

In this paper, an enhanced adaptive nonlinear extended state observer (EANESO) for single-input single-output pure feedback systems in the presence of external time-varying disturbances is proposed. In this paper, a nonlinear system with matched and mismatched disturbances is considered. The conventional extended state observer (ESO) can only be applied to systems that are in the form of integral chains. Moreover, this method has limitations in the face of mismatched disturbances. In the presence of time-varying disturbances, the traditional ESOs cannot estimate the disturbances accurately. To overcome this limitation, an EANESO is proposed in this paper. The main idea is to design the nonlinear ESO (NESO) to estimate the states of the system and multiple disturbances simultaneously. The observer gains are considered time-varying and adjusted with adaptation laws to improve the estimation accuracy and overcome the peaking phenomenon. Next, the proposed controller is designed based on output feedback to eliminate the effects of multiple disturbances and stabilize the closed-loop system. Subsequently, the stability analysis of the closed-loop system and convergence of the observer error are discussed. Finally, the proposed method is applied to the inverted pendulum system. The simulated results show good performance of the proposed method as compared with a recently published scheme in the related literature.

关键词： Nonlinear extended state observer Enhanced adaptive extended state observer Adaptation law Multiple-channel disturbances Inverted pendulum system Time-varying gain

Hybrid Dynamic Variables-Dependent Event-Triggered Fuzzy Model Predictive Control

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

IEEE/CAA Journal of Automatica Sinica 2024年第3期11卷 723-733页

作者： Xiongbo Wan Chaoling Zhang Fan Wei Chuan-Ke Zhang Min Wu IEEE the School of Automation China University of Geosciencesthe Hubei Key Laboratory of Advanced Control and Intelligent Automation for Complex Systemsand the Engineering Research Center of Intelligent Technology for Geo-ExplorationMinistry of EducationWuhan 430074China

This article focuses on dynamic event-triggered mechanism(DETM)-based model predictive control(MPC) for T-S fuzzy systems.A hybrid dynamic variables-dependent DETM is carefully devised,which includes a multiplicative dynamic variable and an additive dynamic variable.The addressed DETM-based fuzzy MPC issue is described as a “min-max” optimization problem(OP).To facilitate the co-design of the MPC controller and the weighting matrix of the DETM,an auxiliary OP is proposed based on a new Lyapunov function and a new robust positive invariant(RPI) set that contain the membership functions and the hybrid dynamic variables.A dynamic event-triggered fuzzy MPC algorithm is developed accordingly,whose recursive feasibility is analysed by employing the RPI set.With the designed controller,the involved fuzzy system is ensured to be asymptotically stable.Two examples show that the new DETM and DETM-based MPC algorithm have the advantages of reducing resource consumption while yielding the anticipated performance.

关键词： Dynamic event-triggered mechanism(DETM) hybrid dynamic variables model predictive control(MPC) robust positive invariant(RPI)set T-S fuzzy systems

Enhancing cut selection through reinforcement learning

在线全文

学校读者我要写书评

暂无评论

science China Mathematics 2024年第6期67卷 1377-1394页

作者： Shengchao Wang Liang Chen Lingfeng Niu Yu-Hong Dai Academy of Mathematics and systems science Chinese Academy of SciencesBeijing100190China research center on Fictitious Economy and Data science Chinese Academy of SciencesBeijing100190China

With the rapid development of artificial intelligence in recent years,applying various learning techniques to solve mixed-integer linear programming(MILP)problems has emerged as a burgeoning research domain.Apart from constructing end-to-end models directly,integrating learning approaches with some modules in the traditional methods for solving MILPs is also a promising direction.The cutting plane method is one of the fundamental algorithms used in modern MILP solvers,and the selection of appropriate cuts from the candidate cuts subset is crucial for enhancing efficiency.Due to the reliance on expert knowledge and problem-specific heuristics,classical cut selection methods are not always transferable and often limit the scalability and generalizability of the cutting plane method.To provide a more efficient and generalizable strategy,we propose a reinforcement learning(RL)framework to enhance cut selection in the solving process of MILPs.Firstly,we design feature vectors to incorporate the inherent properties of MILP and computational information from the solver and represent MILP instances as bipartite graphs.Secondly,we choose the weighted metrics to approximate the proximity of feasible solutions to the convex hull and utilize the learning method to determine the weights assigned to each metric.Thirdly,a graph convolutional neural network is adopted with a self-attention mechanism to predict the value of weighting factors.Finally,we transform the cut selection process into a Markov decision process and utilize RL method to train the model.Extensive experiments are conducted based on a leading open-source MILP solver SCIP.Results on both general and specific datasets validate the effectiveness and efficiency of our proposed approach.

关键词： reinforcement learning mixed-integer linear programming cutting plane method cut selection

Balancing electron transfer and intermediate adsorption ability of metallic Ni-Fe-RE-P bifunctional catalysts via 4f-2p-3d electron interaction for enhanced water splitting

在线全文

学校读者我要写书评

暂无评论

Journal of Energy Chemistry 2024年第7期94卷 458-465页

作者： Hong-Rui Zhao Cheng-Zong Yuan Chenliang Zhou Wenkai Zhao Lunliang Zhang Cong-Hui Li Lei Xin Fuling Wu Shufeng Ye Xiaomeng Zhang Yunfa Chen School of Rare Earths University of Science and Technology of China Jiangxi Province research Institute of Rare Earths Ganjiang Innovation Academy Chinese Academy of Sciences State Key Laboratory of Multiphase complex systems Institute of Process Engineering Chinese Academy of Sciences

Balancing electron transfer and intermediate adsorption ability of bifunctional catalysts via tailoring electronic structures is crucial for green hydrogen production,while it still remains challenging due to lacking efficient strategies.Herein,one efficient and universal strategy is developed to greatly regulate electronic structures of the metallic Ni-Fe-P catalysts via in-situ introducing the rare earth （RE） atoms（Ni-Fe-RE-P,RE=La,Ce,Pr,and Nd）.Accordingly,the as-prepared optimal Ni-Fe-Ce-P/CC selfsupported bifunctional electrodes exhibited superior electrocatalytic activity and excellent stability with the low overpotentials of 247 and 331 mV at 100 mA cm-2for HER and OER,respectively.In the assembled electrolyzer,the Ni-Fe-Ce-P/CC as bifunctional electrodes displayed low operation potential of1.49 V to achieve a current density of 10 mA cm-2,and the catalytic performance can be maintained for 100 h.Experimental results combined with density functional theory （DFT） calculation reveal that Ce doping leads to electron decentralization and crystal structure distortion,which can tailor the band structures and d-band center of Ni-Fe-P,further increasing conductivity and optimizing intermediate adsorption energy.Our work not only proposes a valuable strategy to regulate the electron transfer and intermediate adsorption of electrocatalysts via RE atoms doping,but also provides a deep understanding of regulation mechanism of metallic electrocatalysts for enhanced water splitting.

关键词： Adsorption energy Electron transfer Hydrogen evolution Oxygen evolution RE atoms

Mathematical Analysis on a General Delayed HBV Model with Capsids and Two Infection Routes

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Acta Mathematicae Applicatae Sinica 2024年第2期40卷 508-525页

作者： Li-li LIU Hong-gang WANG Ya-zhi LI Shanxi Key Laboratory of Mathematical Techniques and Big Data Analysis on Disease Control and Prevention Complex Systems Research CenterShanxi UniversityTaiyuan 030006China School of Mathematics and Statistics Qiannan Normal University for NationalitiesDuyun 558000China

Considering that HBV belongs to the DNA virus family and is hepatotropic,we model the HBV DNA-containing capsids as a compartment.In this paper,a delayed HBV infection model is established,where the general incidence function and two infection routes including cell-virus infection and cell-cell infection are introduced.According to some preliminaries,including well-posedness,basic reproduction number and existence of two equilibria,we obtain the threshold dynamics for the model.We illustrate numerical simulations to verify the above theoretical results,and furthermore explore the impacts of intracellular delay and cell-cell infection on the global dynamics of the model.

关键词： delayed HBV model capsids general incidence function two infection routes global stability

Mathematics of multi-agent learning systems at the interface of game theory and artificial intelligence

在线全文

学校读者我要写书评

暂无评论

science China(Information sciences) 2024年第6期67卷 445-447页

作者： Long WANG Feng FU Xingru CHEN center for systems and Control College of EngineeringPeking University center for Multi-Agent research Institute for Artificial IntelligencePeking University Department of Mathematics Dartmouth College Department of Biomedical Data science Geisel School of Medicine at Dartmouth School of science Beijing University of Posts and Telecommunications

Evolutionary game theory (EGT) and artificial intelligence(AI) are two fields that,at first glance,might seem distinct,but they have notable connections and intersections.The former focuses on the evolution of behaviors (or strategies)in a population,where individuals interact with others and update their strategies based on imitation (or social learning).

关键词：

Twisted Integration of complex Oxide Magnetoelectric Heterostructures via Water‑Etching and Transfer Process

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Nano-Micro Letters 2024年第1期16卷 360-369页

作者： Guannan Yang Guohua Dong Butong Zhang Xu Xu Yanan Zhao Zhongqiang Hu Ming Liu State Key Laboratory for Manufacturing systems Engineering Electronic Materials Research LaboratoryKey Laboratory of the Ministry of EducationEngineering Research Center of Spin Quantum Sensor ChipsUniversities of Shaanxi ProvinceSchool of Electronic Science and EngineeringXi’an Jiaotong UniversityXi’an 710049People’s Republic of China

Manipulating strain mode and degree that can be applied to epitaxial complex oxide thin films have been a cornerstone of strain engineering.In recent years,lift-off and transfer technology of the epitaxial oxide thin films have been developed that enabled the integration of heterostructures without the limitation of material types and crystal orientations.Moreover,twisted integration would provide a more interesting strategy in artificial magnetoelectric heterostructures.A specific twist angle between the ferroelectric and ferromagnetic oxide layers corresponds to the distinct strain regulation modes in the magnetoelectric coupling process,which could provide some insight in to the physical phenomena.In this work,the La_(0.67)Sr_(0.33)MnO_(3)(001)/0.7Pb(Mg_(1/3)Nb_(2/3))O_(3)-0.3PbTiO_(3)(011)(LSMO/PMN-PT)heterostructures with 45.and 0.twist angles were assembled via water-etching and transfer process.The transferred LSMO films exhibit a fourfold magnetic anisotropy with easy axis along LSMO.A coexistence of uniaxial and fourfold magnetic anisotropy with LSMO[110]easy axis is observed for the 45°Sample by applying a 7.2 kV cm^(−1)electrical field,significantly different from a uniaxial anisotropy with LSMO[100]easy axis for the 0°Sample.The fitting of the ferromagnetic resonance field reveals that the strain coupling generated by the 45°twist angle causes different lattice distortion of LSMO,thereby enhancing both the fourfold and uniaxial anisotropy.This work confirms the twisting degrees of freedom for magnetoelectric coupling and opens opportunities for fabricating artificial magnetoelectric heterostructures.

关键词： Magnetoelectric heterostructures Twist angle Epitaxial lift-off Magnetic anisotropy Ferromagnetic resonance