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Continued Fraction Algorithm for Matrix Exponentials
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作者 GU Chuan qing Department of Mathematics, College of Sciences, Shanghai University, Shanghai 200436, China 《Journal of Shanghai University(English Edition)》 CAS 2001年第1期11-14,共4页
A recursive rational algorithm for matrix exponentials was obtained by making use of the generalized inverse of a matrix in this paper. On the basis of the n th convergence of Thiele type continued fraction expa... A recursive rational algorithm for matrix exponentials was obtained by making use of the generalized inverse of a matrix in this paper. On the basis of the n th convergence of Thiele type continued fraction expansion, a new type of the generalized inverse matrix valued Padé approximant (GMPA) for matrix exponentials was defined and its remainder formula was proved. The results of this paper were illustrated by some examples. 展开更多
关键词 matrix exponentials generalized inverse continued fraction algorithm Padé approximant
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GROWTH ESTIMATES FOR SINE-TYPE-FUNCTIONS AND APPLICATIONS TO RIESZ BASES OF EXPONENTIALS
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作者 Alexander M. Lindner (Technische Universitat Munchen, Germany) 《Approximation Theory and Its Applications》 2002年第3期26-41,共16页
We present explicit estimates for the growth of sine-type-functions as well as for the derivatives at their zero sets, thus obtaining explicit constants in a result of Levin. The estimates are then used to derive expl... We present explicit estimates for the growth of sine-type-functions as well as for the derivatives at their zero sets, thus obtaining explicit constants in a result of Levin. The estimates are then used to derive explicit lower bounds for exponential Riesz bases, as they arise in Avdonin's Theorem on 1/4 in the mean or in a Theorem, of Bogmtr, Horvath, Job and Seip. An application is discussed, where knowledge of explicit lower bounds of exponential Riese bases is desirable. 展开更多
关键词 GROWTH ESTIMATES FOR SINE-TYPE-FUNCTIONS AND APPLICATIONS TO RIESZ BASES OF exponentials
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Effects of plasma screening on the^(1)P^(o)(n=3,n=4)resonance states of H-and He using the stabilization method
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作者 仲子鑫 吕柄宽 +2 位作者 姜子实 KAR Sabyasachi HO Yew Kam 《黑龙江大学自然科学学报》 2025年第4期469-487,共19页
The effects of plasma screening on the ^(1)P^(o) resonance states of H-and He below the n=3 and n=4 thresholds of the respective subsystemsare investigated using the stabilization method and correlated exponential wav... The effects of plasma screening on the ^(1)P^(o) resonance states of H-and He below the n=3 and n=4 thresholds of the respective subsystemsare investigated using the stabilization method and correlated exponential wave functions.Two plasma mediums,namely,the Debye plasma and quantum plasma environments are considered.The screened Coulomb potential(SCP)obtained from Debye-Hückel model is used to represent Debye plasma environments and the exponential cosine screened Coulomb potential(ECSCP)obtained from a modified Debye-Hückel model is used to represent quantum plasma environments.The resonance parameters(resonance positions and widths)are presented in terms of the screening parameters. 展开更多
关键词 quantum plasma Debye plasma P-wave resonance states correlated exponential wave functions stabilization method
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Exceptional Set for Diophantine Approximation with Primes of Two Squares and Three Biquadrates
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作者 LIU Minmin ZHANG Min LI Jinjiang 《数学进展》 北大核心 2025年第1期18-36,共19页
Suppose thatλ_(1),λ_(2),λ_(3),λ_(4),λ_(5)are nonzero real numbers,not all of the same sign,andλ_(1)/λ_(2)is irrational and algebraic.Let V be a well-spaced sequence,δ>0.In this paper,it is proved that,for ... Suppose thatλ_(1),λ_(2),λ_(3),λ_(4),λ_(5)are nonzero real numbers,not all of the same sign,andλ_(1)/λ_(2)is irrational and algebraic.Let V be a well-spaced sequence,δ>0.In this paper,it is proved that,for anyε>0,the number of v∈V with v≤N such that the following inequality|λ_(1)p_(1)~2+λ_(2)p_(2)~2+λ_(3)p_(3)~4+λ_(4)p_(4)~4+λ_5p_5~4-v|<v^(-δ)has no solution in prime variables p_(1),p_(2),p_(3),p_(4),p_(5)does not exceed O(N^(29/32+2δ+ε)). 展开更多
关键词 Diophantine approximation exponential sum Davenport-Heilbronn method prime variable
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Optimal Investment Strategy for an Insurer in Two Currency Markets
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作者 ZHOU Qianqian 《应用概率统计》 北大核心 2025年第1期1-16,共16页
In this paper,we study the optimal investment problem of an insurer whose surplus process follows the diffusion approximation of the classical Cramer-Lundberg model.Investment in the foreign markets is allowed,and the... In this paper,we study the optimal investment problem of an insurer whose surplus process follows the diffusion approximation of the classical Cramer-Lundberg model.Investment in the foreign markets is allowed,and therefore,the foreign exchange rate model is incorporated.Under the allowing of selling and borrowing,the problem of maximizing the expected exponential utility of terminal wealth is studied.By solving the corresponding Hamilton-Jacobi-Bellman equations,the optimal investment strategies and value functions are obtained.Finally,numerical analysis is presented. 展开更多
关键词 Cramer-Lundberg model exponential utility Hamilton-Jacobi-Bellman equation optimal investment strategy foreign exchange rate
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Normalized Positive Ground State Solutions for Nonhomogeneous Kirchhoff Equations
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作者 ZHANG Xiaocang XU Liping 《应用数学》 北大核心 2025年第3期711-720,共10页
This article studies a class of nonlinear Kirchhoff equations with exponential critical growth,trapping potential,and perturbation.Under appropriate assumptions about f and h,the article obtained the existence of norm... This article studies a class of nonlinear Kirchhoff equations with exponential critical growth,trapping potential,and perturbation.Under appropriate assumptions about f and h,the article obtained the existence of normalized positive solutions for this equation via the Trudinger-Moser inequality and variational methods.Moreover,these solutions are also ground state solutions.Additionally,the article also characterized the asymptotic behavior of solutions.The results of this article expand the research of relevant literature. 展开更多
关键词 Normalized positive ground state solution Nonhomogeneous Kirchhoff equation Variational method Exponential critical growth Trapping potential
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Distance Sets Relating to Orthogonal Exponentials
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作者 Jian Lin LI 《Acta Mathematica Sinica,English Series》 SCIE CSCD 2011年第12期2409-2414,共6页
The aim of this paper is to investigate the size properties of a planar set whose distance set has some prescribed arithmetic combinatorics. Such research is motivated by the conjecture that the disk has no more than ... The aim of this paper is to investigate the size properties of a planar set whose distance set has some prescribed arithmetic combinatorics. Such research is motivated by the conjecture that the disk has no more than 3 orthogonal exponentials. By proving a shifted version of ErdSs-Solymosi's theorem on the distance sets, we give some grounds on the conjecture. The results obtained here extend the corresponding results of Iosevich and Jaming in a simple manner. 展开更多
关键词 Distance sets orthogonal exponentials convex sets algebraic number and transcendental number
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Stability analysis of conformable fractional order systems
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作者 Imed Basdouri Souad Kasmi Jean Lerbet 《Applied Mathematics(A Journal of Chinese Universities)》 2025年第3期752-762,共11页
In this paper, we study the stability of a class of conformable fractional-order systems using the Lyapunov function. We assume that the nonlinear part of the system satisfies the one-sided Lipschitz condition and the... In this paper, we study the stability of a class of conformable fractional-order systems using the Lyapunov function. We assume that the nonlinear part of the system satisfies the one-sided Lipschitz condition and the quadratic inner-bounded condition. We provide some sufficient conditions that ensure the asymptotic stability of the system. Furthermore, we present the construction of a feedback stabilizing controller for conformable fractional bilinear systems. 展开更多
关键词 conformable fractional exponential stability asymptotical stability one-sided Lipschitz
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Exponential Stability of Impulsive System via Saturated Sliding Mode Control
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作者 Miaomiao Yu Xiaodi Li 《IEEE/CAA Journal of Automatica Sinica》 2025年第2期469-471,共3页
Dear Editor,This letter presents a class of saturated sliding mode control (SMC)strategy for linear systems subject to impulsive disturbance and input saturation. To ensure the feasibility of proposed SMC under satura... Dear Editor,This letter presents a class of saturated sliding mode control (SMC)strategy for linear systems subject to impulsive disturbance and input saturation. To ensure the feasibility of proposed SMC under saturation, a relationship is established among attraction domain, saturation structure and control gain. 展开更多
关键词 linear systems attraction domain saturated sliding mode control impulsive disturbance saturation structure exponential stability impulsive system
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A Flexible Exponential Log-Logistic Distribution for Modeling Complex Failure Behaviors in Reliability and Engineering Data
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作者 Hadeel Al Qadi Fatimah M.Alghamdi +2 位作者 Hamada H.Hassan Mohamed E.Mead Ahmed Z.Afify 《Computer Modeling in Engineering & Sciences》 2025年第8期2029-2061,共33页
Parametric survival models are essential for analyzing time-to-event data in fields such as engineering and biomedicine.While the log-logistic distribution is popular for its simplicity and closed-form expressions,it ... Parametric survival models are essential for analyzing time-to-event data in fields such as engineering and biomedicine.While the log-logistic distribution is popular for its simplicity and closed-form expressions,it often lacks the flexibility needed to capture complex hazard patterns.In this article,we propose a novel extension of the classical log-logistic distribution,termed the new exponential log-logistic(NExLL)distribution,designed to provide enhanced flexibility in modeling time-to-event data with complex failure behaviors.The NExLL model incorporates a new exponential generator to expand the shape adaptability of the baseline log-logistic distribution,allowing it to capture a wide range of hazard rate shapes,including increasing,decreasing,J-shaped,reversed J-shaped,modified bathtub,and unimodal forms.A key feature of the NExLL distribution is its formulation as a mixture of log-logistic densities,offering both symmetric and asymmetric patterns suitable for diverse real-world reliability scenarios.We establish several theoretical properties of the model,including closed-form expressions for its probability density function,cumulative distribution function,moments,hazard rate function,and quantiles.Parameter estimation is performed using seven classical estimation techniques,with extensive Monte Carlo simulations used to evaluate and compare their performance under various conditions.The practical utility and flexibility of the proposed model are illustrated using two real-world datasets from reliability and engineering applications,where the NExLL model demonstrates superior fit and predictive performance compared to existing log-logistic-basedmodels.This contribution advances the toolbox of parametric survivalmodels,offering a robust alternative formodeling complex aging and failure patterns in reliability,engineering,and other applied domains. 展开更多
关键词 Failure rate new exponential class log-logistic distribution maximum likelihood order statistics reallife data analysis
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GLOBAL WELL-POSEDNESS FOR THE 3D INCOMPRESSIBLE HEAT-CONDUCTING MAGNETOHYDRODYNAMIC FLOWS WITH TEMPERATURE-DEPENDENT COEFFICIENTS
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作者 Qingyan LI Zhenhua GUO 《Acta Mathematica Scientia》 2025年第3期951-981,共31页
In this paper,we consider an initial boundary value problem for the nonhomo-geneous heat-conducting magnetohydrodynamic fuids when the viscosityμ,magnetic dif-fusivity v and heat conductivity k depend on the temperat... In this paper,we consider an initial boundary value problem for the nonhomo-geneous heat-conducting magnetohydrodynamic fuids when the viscosityμ,magnetic dif-fusivity v and heat conductivity k depend on the temperature according to μ(0)=°,k(0)=08,v(0)=07,withα,>0,β≥0.We prove the global existence of a unique strong solution provided that ■ is suitably small.In addition,we also get some results of the large-time behavior and exponential decay estimates. 展开更多
关键词 incompressible heat-conducting magnetohydrodynamic equations temperature-dependent coefficients strong solutions global existence exponential decay
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MULTIPLICITY AND CONCENTRATION OF SOLUTIONS TO A FRACTIONAL N/S-LAPLACIAN PROBLEM WITH EXPONENTIAL CRITICAL GROWTH AND POTENTIALS COMPETITION
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作者 Wei CHEN Chao JI Nguyen Van THIN 《Acta Mathematica Scientia》 2025年第3期885-918,共34页
By using the Ljusternik-Schnirelmann category and variational method,we s-tudy the existence,multiplicity and concentration of solutions to the fractional Schrodinger equation with potentials competition as follows,ε... By using the Ljusternik-Schnirelmann category and variational method,we s-tudy the existence,multiplicity and concentration of solutions to the fractional Schrodinger equation with potentials competition as follows,ε^(N)(-△)^(s)N/sμ+V(x)|μ|^(N/s-2μ)=Q(x)h(μ)in R^(N),where ε>0 is a parameter,s ∈(0,1),2≤p<+oo and N=ps.The nonlinear term h is a diferentiable function with exponential critical growth,the absorption potential V and the reaction potential Q are continuous functions. 展开更多
关键词 exponential critical growth fractional p-Laplace Ljusternik-Schnirelmann the-ory mountain pass theorem Trudinger-Moser inequality variational methods
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High Energy Normalized Solutions for the Schrodinger Equations with Exponential Critical Growth
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作者 ZHANG Xiao-cang XULi-ping 《Chinese Quarterly Journal of Mathematics》 2025年第1期1-19,共19页
In this paper,we study high energy normalized solutions for the following Schr?dinger equation{-Δu+V(x)u+λu=f(u),in R^(2),∫_(R^(2))|u|^(2)dx=c,where c>0,λ∈R will appear as a Lagrange multiplier,V(x)=ω|x|2 rep... In this paper,we study high energy normalized solutions for the following Schr?dinger equation{-Δu+V(x)u+λu=f(u),in R^(2),∫_(R^(2))|u|^(2)dx=c,where c>0,λ∈R will appear as a Lagrange multiplier,V(x)=ω|x|2 represents a trapping potential,and f has an exponential critical growth.Under the appropriate assumptions of f,we have obtained the existence of normalized solutions to the above Schr?dinger equation by introducing a variational method.And these solutions are also high energy solutions with positive energy. 展开更多
关键词 High energy normalized solutions Schrodinger equation Trapping potential Exponential critical growth Variational method
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Exponential Attitude-Orbit Coordinated Control for Gravitational-Wave Detection Spacecraft Formation with Large-Scale Communication Delays
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作者 XING Youpeng SONG Yinsheng +1 位作者 YIN Zeyang CHEN Xiaofang 《Transactions of Nanjing University of Aeronautics and Astronautics》 2025年第1期70-79,共10页
This paper concerns the exponential attitude-orbit coordinated control problems for gravitational-wave detection formation spacecraft systems.Notably,the large-scale communication delays resulting from oversized inter... This paper concerns the exponential attitude-orbit coordinated control problems for gravitational-wave detection formation spacecraft systems.Notably,the large-scale communication delays resulting from oversized inter-satellite distance of space-based laser interferometers are first modeled.Subject to the delayed communication behaviors,a new delay-dependent attitude-orbit coordinated controller is designed.Moreover,by reconstructing the less conservative Lyapunov-Krasovskii functional and free-weight matrices,sufficient criteria are derived to ensure the exponential stability of the closed-loop relative translation and attitude error system.Finally,a simulation example is employed to illustrate the numerical validity of the proposed controller for in-orbit detection missions. 展开更多
关键词 gravitational-wave detection spacecraft formation attitude-orbit coordinated control large-scale communication delays exponential stability
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High Accuracy Simulation of Electro-Thermal Flow for Non-Newtonian Fluids in BioMEMS Applications
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作者 Umer Farooq Nabil Kerdid +1 位作者 Yasir Nawaz Muhammad Shoaib Arif 《Computer Modeling in Engineering & Sciences》 2025年第7期873-898,共26页
In this study,we proposed a numerical technique for solving time-dependent partial differential equations that arise in the electro-osmotic flowofCarreau fluid across a stationary plate based on amodified exponential ... In this study,we proposed a numerical technique for solving time-dependent partial differential equations that arise in the electro-osmotic flowofCarreau fluid across a stationary plate based on amodified exponential integrator.The scheme is comprised of two explicit stages.One is the exponential integrator type stage,and the second is the Runge-Kutta type stage.The spatial-dependent terms are discretized using the compact technique.The compact scheme can achieve fourth or sixth-order spatial accuracy,while the proposed scheme attains second-order temporal accuracy.Also,a mathematical model for the electro-osmotic flow of Carreau fluid over the stationary sheet is presented with heat and mass transfer effects.The governing equations are transformed into dimensionless partial differential equations and solved by the proposed scheme.Simulation results reveal that increasing the Helmholtz-Smoluchowski velocityUHS by 400%leads to a 60%-75%rise in peak flowvelocity,while the electro-osmotic parameter me enhances near-wall acceleration.Conversely,velocity decreases significantly with higher Weissenberg numbers,indicating the Carreau fluid’s elastic resistance and increased magnetic field strength due to improved Lorentz forces.Temperature rises with the thermal conductivity parameter 2,while higher reaction ratesγdiminish concentration and local Sherwood number values.The simulation findings show the scheme’s correctness and efficacy in capturing the complicated interactions in non-Newtonian electro-osmotic transport by revealing the notable impact of electrokinetic factors on flowbehaviour.Theproposedmodel is particularly relevant for BiologicalMicro-Electro-Mechanical Systems(BioMEMS)applications,where precise control of electro-thermal transport in non-Newtonian fluids is critical for lab-on-a-chip diagnostics,drug delivery,and micro-scale thermal management. 展开更多
关键词 Modified exponential integrator stability CONVERGENCE carreau fluid:electro-osmosis flow BioMEMS applications
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EXPONENTIAL STABILITY OF ATTRACTOR FOR RANDOM REACTION-DIFFUSION EQUATION DRIVEN BY NONLINEAR COLORED NOISE ON R^(N)
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作者 Huijuan ZHU Xiaojun LI Yanjiao LI 《Acta Mathematica Scientia》 2025年第4期1567-1596,共30页
In this paper, we consider the existence of pullback random exponential attractor for non-autonomous random reaction-diffusion equation driven by nonlinear colored noise defined onR^(N) . The key steps of the proof ar... In this paper, we consider the existence of pullback random exponential attractor for non-autonomous random reaction-diffusion equation driven by nonlinear colored noise defined onR^(N) . The key steps of the proof are the tails estimate and to demonstrate the Lipschitz continuity and random squeezing property of the solution for the equation defined on R^(N) . 展开更多
关键词 random reaction-diffusion equation continuous cocycle pullback random attractor fractal dimension random exponential attractor
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Piecewise pseudo almost automorphic solution for impulsive Lasota-Wazewska model with mixed delays
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作者 Meryem Abdelaziz Farouk Cherif 《Applied Mathematics(A Journal of Chinese Universities)》 2025年第1期102-121,共20页
In this paper,the existence,uniqueness,asymptotic and global exponential stability of pseudo almost automorphic solution for a class of delayed Lasota-Wazewska model with impulsive effects are established by applying ... In this paper,the existence,uniqueness,asymptotic and global exponential stability of pseudo almost automorphic solution for a class of delayed Lasota-Wazewska model with impulsive effects are established by applying an appropriate fixed point theorem and Lyapunov functional method.Finally,a numerical example with simulation is given to illuminate our theoretical results. 展开更多
关键词 Lasota-Wazewska model existence and uniqueness pseudo almost automorphic asymptotic and exponential stability
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Chattering-free terminal sliding mode control based on adaptive exponential reaching barrier function for a chaotic permanent magnet synchronous generator in offshore wind turbine system
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作者 Aissa Benabdeseelam Manal Messadi +1 位作者 Karim Kemih Hamid Hamiche 《Chinese Physics B》 2025年第9期104-113,共10页
This paper introduces a novel chattering-free terminal sliding mode control(SMC)strategy to address chaotic behavior in permanent magnet synchronous generators(PMSG)for offshore wind turbine systems.By integrating an ... This paper introduces a novel chattering-free terminal sliding mode control(SMC)strategy to address chaotic behavior in permanent magnet synchronous generators(PMSG)for offshore wind turbine systems.By integrating an adaptive exponential reaching law with a continuous barrier function,the proposed approach eliminates chattering and ensures robust performance under model uncertainties.The methodology combines adaptive SMC with dynamic switching to estimate and compensates for unknown uncertainties,providing smooth and stable control.Finally,the performance and effectiveness of the proposed approach are compared with those of a previous study. 展开更多
关键词 permanent magnet synchronous generator chaotic system terminal sliding mode control exponential reaching adaptive barrier function chattering-free unknown uncertainty
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Analysis and design of multivalued many-to-one associative memory driven by external inputs
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作者 Qiang Fang Hao Zhang 《Chinese Physics B》 2025年第8期331-341,共11页
This paper proposes a novel multivalued recurrent neural network model driven by external inputs,along with two innovative learning algorithms.By incorporating a multivalued activation function,the proposed model can ... This paper proposes a novel multivalued recurrent neural network model driven by external inputs,along with two innovative learning algorithms.By incorporating a multivalued activation function,the proposed model can achieve multivalued many-to-one associative memory,and the newly developed algorithms enable effective storage of many-to-one patterns in the coefficient matrix while maintaining the indispensability of inputs in many-to-one associative memory.The proposed learning algorithm addresses a critical limitation of existing models which fail to ensure completely erroneous outputs when facing partial input missing in many-to-one associative memory tasks.The methodology is rigorously derived through theoretical analysis,incorporating comprehensive verification of both the existence and global exponential stability of equilibrium points.Demonstrative examples are provided in the paper to show the effectiveness of the proposed theory. 展开更多
关键词 many-to-one associative memories recurrent neural network global exponential stability external input
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Time-Varying Formation Tracking Control of Heterogeneous Multi-Agent Systems With Intermittent Communications and Directed Switching Networks
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作者 Yuhan Wang Zhuping Wang +1 位作者 Hao Zhang Huaicheng Yan 《IEEE/CAA Journal of Automatica Sinica》 2025年第1期294-296,共3页
Dear Editor,This letter is concerned with the problem of time-varying formation tracking for heterogeneous multi-agent systems(MASs) under directed switching networks. For this purpose, our first step is to present so... Dear Editor,This letter is concerned with the problem of time-varying formation tracking for heterogeneous multi-agent systems(MASs) under directed switching networks. For this purpose, our first step is to present some sufficient conditions for the exponential stability of a particular category of switched systems. 展开更多
关键词 switched systems time varying formation tracking directed switching networks heterogeneous multi agent systems intermittent communications exponential stability
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