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event-triggered H_(∞) consensus control for input-constrained multi-agent systems via reinforcement learning

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Control Theory and Technology 2024年第1期22卷 25-38页

作者： Jinxuan Zhang Chang-e ren College of Information engineering Capital Normal UniversityBeijing100089China

This article presents an event-triggered H_(∞) consensus control scheme using reinforcement learning (RL) for nonlinear second-order multi-agent systems (MASs) with control constraints. First, considering control constraints, the constrained H_(∞) consensus problem is transformed into a multi-player zero-sum game with non-quadratic performance functions. Then, an event-triggered control method is presented to conserve communication resources and a new triggering condition is developed for each agent to make the triggering threshold independent of the disturbance attenuation level. To derive the optimal controller that can minimize the cost function in the case of worst disturbance, a constrained Hamilton–Jacobi–bellman (HJb) equation is defined. Since it is difficult to solve analytically due to its strongly non-linearity, reinforcement learning (RL) is implemented to obtain the optimal controller. In specific, the optimal performance function and the worst-case disturbance are approximated by a time-triggered critic network;meanwhile, the optimal controller is approximated by event-triggered actor network. After that, Lyapunov analysis is utilized to prove the uniformly ultimately bounded (UUb) stability of the system and that the network weight errors are UUb. Finally, a simulation example is utilized to demonstrate the effectiveness of the control strategy provided.

关键词： H_(∞)optimal control Input constrains Multi-agent systems(MASs) Reinforcement learning(RL)

Dissociation of the N400 component between linguistic and non-linguistic processing: A source analysis study

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World Journal of Neuroscience 2014年第1期4卷 25-39页

作者： Anne Gallagher renée béland Phetsamone Vannasing Maria Luisa bringas Pedro Valdes Sosa Nelson J. Trujillo-barreto John Connolly Maryse Lassonde Centre de Recherche en Neuropsychologie et Cognition Psychologie Department University of Montreal Montreal Canada Centro de Neurosciencias Havana Cuba CHU Ste-Justine Research Center Montreal Canada International Center for Neurological Rehabilitation (CIren) Havana Cuba Language Memory & Brain Laboratories Department of Linguistics & Languages McMaster University Hamilton Canada

The N400 component is commonly associated with the detection of linguistic incongruity. A few studies have shown that the N400 can also be elicited by non-linguistic stimuli. Different spatiotemporal patterns were observed between the typical Linguistic N400 and the Non-linguistic N400, suggesting distinct brain generators. The aim of this study was to investigate the presence of an N400 in response to linguistic and non-linguistic stimuli, and to specify anatomical sources of both N400s using a novel analysis method: the bayesian Model Averaging (bMA) distributed source model. Picture-word and environmental soundpicture associations, either congruent or incongruent, were presented to ten young healthy adults while highdensity eRP recordings were made. Standard electrophysiological analyses confirmed that the N400 was not specific to linguistic incongruity but was also elicited by environmental sound-picture incongruities. Different topographic distributions were obtained for the Linguistic N400 and Non-linguistic N400. bMA analysis showed that the Linguistic N400 generators were mostly located in the left superior temporal gyrus, whereas the sources of the Non-linguistic N400 were identified mostly in the right middle and superior temporal gyri. Detection of linguistic incongruities recruited cerebral areas commonly associated with language processing, whereas non-linguistic incongruities recruited right cerebral regions usually associated with auditory processing of non-linguistic stimuli. The Linguistic and Non-linguistic N400s appear to be elicited by similar cognitive mechanisms assumed by different cerebral areas depending on the type of material to be processed. The present findings support the existence of parallel pathways for the processing of linguistic and non-linguistic incongruities.

关键词： event-Related Potentials Incongruity Semantic environmental Sounds Distributed Source Model bMA

A FAS approach for stabilization of generalized chained forms: part 1. Discontinuous control laws

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Science China(Information Sciences) 2024年第2期67卷 118-143页

作者： Guang-ren DUAN Center for Control Theory and Guidance Technology Harbin Institute of Technology Center for Control Science and Technology Southern University of Science and Technology

In this paper, a type of general nonholonomic systems is proposed, which contains both the brockett’s two example systems, and their extended n-dimensional chained forms, as special cases. For the stabilization of such systems, a stabilizing controller is proposed based on the fully actuated system(FAS)approach, which is discontinuous at the origin but time-invariant when the open-loop system is time-invariant,and drives the feasible trajectories of the system to the origin exponentially. Furthermore, the proposed FAS approach is also extended to the sub-normal system case and the time-delay system case.

关键词： nonholonomic systems feedback stabilization exponential convergence sub-fully actuated systems time-delay systems

Skeletal stem cells in bone development,homeostasis,and disease

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Protein & Cell 2024年第8期15卷 559-574页

作者： Guixin Yuan Xixi Lin Ying Liu Matthew b.Greenblatt ren Xu The First Affliated Hospital of Xiamen University-ICMRS Collaborating Center for Skeletal Stem Cell State Key Laboratory of Cellular Stress BiologySchool of MedicineFaculty of Medicine and Life SciencesXiamen UniversityXiamen 361005China Xiamen Key Laboratory of Regeneration Medicine Fujian Provincial Key Laboratory of Organ and Tissue RegenerationOrgan Transplantation InstituteSchool of MedicineXiamen UniversityXiamen 361102China Department of Pathology and Laboratory Medicine Weill Cormell Medical CollegeNew YorkNY 10065USA Research Division Hospital for Special SurgeryNew YorkNY10065USA

Tissue-resident stem cells are essential for development and repair,and in the skeleton,this function is fulfilled by recently identified skeletal stem cells(SSCs).However,recent work has identified that SSCs are not monolithic,with long bones,craniofacial sites,and the spine being formed by distinct stem *** studies have utilized techniques such as fluorescence-activated cell sorting,lineage tracing,and single-cell sequencing to investigate the involvement of ssCs in bone development,homeostasis,and *** investigations have allowed researchers to map the lineage commitment trajectory of ssCs in different parts of the body and at different time ***,recent studies have shed light on the characteristics of ssCs in both physiological and pathological *** review focuses on discussing the spatiotemporal distribution of ssCs and enhancing our understanding of the diversity and plasticity of ssCs by summarizing recent discoveries.

关键词： skeletal stem cells bone development endochondral ossification intramembranous ossification lineage tracing

A FAS approach for stabilization of generalized chained forms: part 2. Continuous control laws

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Science China(Information Sciences) 2024年第3期67卷 114-135页

作者： Guang-ren DUAN Center for Control Theory and Guidance Technology Harbin Institute of Technology Shenzhen Key Laboratory of Control Theory and Intelligent Systems Southern University of Science and Technology

In this paper, continuous time-varying stabilizing controllers for the type of general nonholonomic systems proposed and treated in part 1 are designed using the fully actuated system(FAS) approach. The key step is to differentiate the first scalar equation, and by control of the obtained second-order scalar system, a proportional plus integral feedback form for the first control variable is obtained. With the solution to this designed second-order scalar system, the rest equations in the nonholonomic system form an independent time-varying subsystem which is then handled by the FAS approach. The overall designed controller contains an almost arbitrarily chosen design parameter, and is proven to guarantee the uniformly and globally exponential stability of the closed-loop system. The proposed approach is simple and effective,and is demonstrated with a practical example of ship control.

关键词： nonholonomic systems feedback stabilization fully actuated systems Lyapunov stability continuous controllers

Resilient control of flexible hypersonic vehicles against unmatched distributed faults

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Chinese Journal of Aeronautics 2024年第5期37卷 60-70页

作者： Dong ZHAO Wenjing ren School of Artificial Intelligence Anhui UniversityHefei 230601China Key Laboratory of System Control and Information Processing Ministry of EducationShanghai Jiao Tong UniversityShanghai 200240China School of electrical engineering and Automation Hefei University of TechnologyHefei 230009China

This paper studies a robust fault compensation and vibration suppression problem of flexible hypersonic *** controlled plant is represented by a cascade system composed of a nonlinear Ordinary Differential equation(ODe)and an euler-bernoulli beam equation(ebbe),in which the vibration dynamics is coupled with the rigid dynamics and suffers from distributed faults.A state differential transformation is introduced to transfer distributed faults to an ebbe boundary and a longitudinal dynamics is refined by utilizing T-S fuzzy IF-THeN rules.A novel T-S fuzzy based fault-tolerant control algorithm is developed and related stability conditions are *** robust exponential stability and well-posedness are proved by using the modified l_(0)-semigroup based Lyapunov direct approach.A simulation study on the longitudinal dynamics of flexible hypersonic vehicles effectively verifies the validity of the developed theoretical results.

关键词： Flexible hypersonic vehicles ODe-ebbe cascade Robust exponential stability Unmatched distributed fault compensation Vibration suppression

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Progress in modeling and control of probe-and-drogue autonomous aerial refueling

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Chinese Journal of Aeronautics 2024年第5期37卷 6-26,I0001页

作者： Jinrui ren Quan QUAN School of Automation Xi’an University of Posts&TelecommunicationsXi'an 710072China School of Automation Science and electrical engineering Beihang UniversityBeijing 100191China

by refueling aircraft while they are in flight,aerial refueling is an efficient technique to extend their endurance and *** Aerial Refueling(AAR)is anticipated to be used to complete aerial refueling for unmanned *** are three aerial refueling methods:the Probe-and-Drogue Refueling(PDR)refueling method,the flying-boom refueling method,and the boom-drogue-adapter refueling *** paper considers the PDR approach,the most challenging of the three,because the flexible hose-drogue assembly has fast dynamics and is susceptible to various kinds of winds,which makes the probe docking with the drogue *** is divided into four phases,namely the rendezvous phase,joining phase,refueling phase,and reform phase,with the refueling phase being the most *** controller design faces the greatest challenge during the docking control of the refueling phase since it calls for a high level of safety,precision,and *** a result,the modeling and control issues encountered during the refueling phase are typical and *** fundamental idea of AAR is presented in the paper first,after which the characteristics and requirements of AAR are *** progress in modeling and control techniques for the AAR’s refueling phase is then systematically ***,potential future work for high safety,precision,and efficiency requirements is examined and suggested.

关键词： Aerial refueling Probe-and-drogue refueling Docking Flight controlsystems Unmanned Aerial Vehicles

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Nonlocal symmetries,soliton-cnoidal wave solution and soliton molecules to a(2+1)-dimensional modified KdV system

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Communications in Theoretical Physics 2024年第4期76卷 14-21页

作者： Jianyong Wang bo ren Department of Mathematics and Physics Quzhou UniversityQuzhou 324000China Department of Mathematics Zhejiang University of TechnologyHangzhou 310014China

A(2+1)-dimensional modified KdV(2DmKdV)system is considered from several ***,residue symmetry,a type of nonlocal symmetry,and the bäcklund transformation are obtained via the truncated Painlevéexpansion ***,the residue symmetry is localized to a Lie point symmetry of a prolonged system,from which the finite transformation group is ***,the integrability of the 2DmKdV system is examined under the sense of consistent tanh expansion ***,explicit soliton-cnoidal wave solutions are ***,abundant patterns of soliton molecules are presented by imposing the velocity resonance condition on the multiple-soliton solution.

关键词： soliton-cnoidal wave solution nonlocal symmetry soliton molecule (2+1)-dimensional modified KdV system

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Metal-Organic Frameworks Housing Active Molecules as bioinspired Catalysts

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CCS Chemistry 2024年第6期6卷 1380-1402页

作者： Yin Zhang Peter e.VanNatta Junyu ren Shengqian Ma Department of Chemistry University of North TexasDentonTexas 76201 Department of Chemical and biomolecular engineering National University of SingaporeSingapore 117585

Optimization of activity,selectivity,and stability of catalysts for practical application is a long-soughtafter *** progress in the advancement of rational catalyst design routinely takes queues from ***,enzymes are renowned for their high efficiency and selectivity in diverse and significant reactions under mild *** the well-known merits of enzymes,they often remain unsuitable for industrial catalysis due to issues,including limited environment(solvent/temperature/pH)compatibility,considerable structural uncertainty,and highly specific reaction *** the context of bioinspired catalysis design,the development of synthetic heterogeneous catalyst analogs,which may not only mimic enzymes to reproduce or even surpass their performance but also bypass their intrinsic limitations,is thus,desirable and has been extensively studied in the context of porous *** metal-organic framework(MOF)is a superior candidate for porous materials towards this goal,thanks to facile and modular preparation,explicit crystalline composition/structure,tunable pore size/environment,and excellent *** introduction of active molecular species such as bioactive molecules(e.g.,proteins,enzymes,peptides,amino acids,porphyrins)and chemically active molecules(e.g.,frustrated Lewis pairs)into metal-organic frameworks(MOFs)via pore encapsulation,chemical postmodification,or bottom-up construction has been shown to facilitate the cooperative enhancement of catalysis through the enforcement of proximity,enhancement of control/activity,and even inducement of unexpected *** this minireview,we sought to summarize the last 5 years of fruitful progress,exploiting MOFs housing active molecules for substantial catalysis applications,including asymmetric reactions,CO_(2)conversion(reduction,cycloaddition),biocatalytic H_(2)O_(2)/dye degradation,and so on,and discuss challenges and opportunities in the prospective exploration of these system

关键词： metal-organic framework bioinspired catalyst active molecular species