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Improved Oustaloup approximation of fractional-order operators using adaptive chaotic particle swarm optimization 被引量:7
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作者 Zhe Gao Xiaozhong Liao 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2012年第1期145-153,共9页
A rational approximation method of the fractional-order derivative and integral operators is proposed. The turning fre- quency points are fixed in each frequency interval in the standard Oustaloup approximation. In th... A rational approximation method of the fractional-order derivative and integral operators is proposed. The turning fre- quency points are fixed in each frequency interval in the standard Oustaloup approximation. In the improved Oustaloup method, the turning frequency points are determined by the adaptive chaotic particle swarm optimization (PSO). The average velocity is proposed to reduce the iterations of the PSO. The chaotic search scheme is combined to reduce the opportunity of the premature phenomenon. Two fitness functions are given to minimize the zero-pole and amplitude-phase frequency errors for the underlying optimization problems. Some numerical examples are compared to demonstrate the effectiveness and accuracy of this proposed rational approximation method. 展开更多
关键词 fractional-order calculus rational approximation particle swarm optimization (PSO) tent map.
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A Q-Learning Improved Particle Swarm Optimization for Aircraft Pulsating Assembly Line Scheduling Problem Considering Skilled Operator Allocation
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作者 Xiaoyu Wen Haohao Liu +6 位作者 Xinyu Zhang Haoqi Wang Yuyan Zhang Guoyong Ye Hongwen Xing Siren Liu Hao Li 《Computers, Materials & Continua》 2026年第1期1503-1529,共27页
Aircraft assembly is characterized by stringent precedence constraints,limited resource availability,spatial restrictions,and a high degree of manual intervention.These factors lead to considerable variability in oper... Aircraft assembly is characterized by stringent precedence constraints,limited resource availability,spatial restrictions,and a high degree of manual intervention.These factors lead to considerable variability in operator workloads and significantly increase the complexity of scheduling.To address this challenge,this study investigates the Aircraft Pulsating Assembly Line Scheduling Problem(APALSP)under skilled operator allocation,with the objective of minimizing assembly completion time.A mathematical model considering skilled operator allocation is developed,and a Q-Learning improved Particle Swarm Optimization algorithm(QLPSO)is proposed.In the algorithm design,a reverse scheduling strategy is adopted to effectively manage large-scale precedence constraints.Moreover,a reverse sequence encoding method is introduced to generate operation sequences,while a time decoding mechanism is employed to determine completion times.The problem is further reformulated as a Markov Decision Process(MDP)with explicitly defined state and action spaces.Within QLPSO,the Q-learning mechanism adaptively adjusts inertia weights and learning factors,thereby achieving a balance between exploration capability and convergence performance.To validate the effectiveness of the proposed approach,extensive computational experiments are conducted on benchmark instances of different scales,including small,medium,large,and ultra-large cases.The results demonstrate that QLPSO consistently delivers stable and high-quality solutions across all scenarios.In ultra-large-scale instances,it improves the best solution by 25.2%compared with the Genetic Algorithm(GA)and enhances the average solution by 16.9%over the Q-learning algorithm,showing clear advantages over the comparative methods.These findings not only confirm the effectiveness of the proposed algorithm but also provide valuable theoretical references and practical guidance for the intelligent scheduling optimization of aircraft pulsating assembly lines. 展开更多
关键词 Aircraft pulsating assembly lines skilled operator reinforcement learning PSO reverse scheduling
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Distributed Adaptive Cooperative Tracking of Uncertain Nonlinear Fractional-order Multi-agent Systems 被引量:17
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作者 Zhitao Li Lixin Gao +1 位作者 Wenhai Chen Yu Xu 《IEEE/CAA Journal of Automatica Sinica》 EI CSCD 2020年第1期292-300,共9页
In this paper, the leader-following tracking problem of fractional-order multi-agent systems is addressed. The dynamics of each agent may be heterogeneous and has unknown nonlinearities. By assumptions that the intera... In this paper, the leader-following tracking problem of fractional-order multi-agent systems is addressed. The dynamics of each agent may be heterogeneous and has unknown nonlinearities. By assumptions that the interaction topology is undirected and connected and the unknown nonlinear uncertain dynamics can be parameterized by a neural network, an adaptive learning law is proposed to deal with unknown nonlinear dynamics, based on which a kind of cooperative tracking protocols are constructed. The feedback gain matrix is obtained to solve an algebraic Riccati equation. To construct the fully distributed cooperative tracking protocols, the adaptive law is also adopted to adjust the coupling weight. With the developed control laws,we can prove that all signals in the closed-loop systems are guaranteed to be uniformly ultimately bounded. Finally, a simple simulation example is provided to illustrate the established result. 展开更多
关键词 Adaptive control CONSENSUS distributed control fractional-order systems multi-agent system
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Creep constitutive model for damaged soft rock based on fractional-order nonlinear theory 被引量:1
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作者 BAO Min ZHOU Zihan +1 位作者 CHEN Zhonghui ZHANG Lingfei 《Journal of Mountain Science》 2025年第6期2276-2290,共15页
Investigating the combined effects of mining damage and creep damage on slope stability is crucial,as it can comprehensively reveal the non-linear deformation characteristics of rock under their joint influence.This s... Investigating the combined effects of mining damage and creep damage on slope stability is crucial,as it can comprehensively reveal the non-linear deformation characteristics of rock under their joint influence.This study develops a fractional-order nonlinear creep constitutive model that incorporates the double damage effect and implements a non-linear creep subroutine for soft rock using the threedimensional finite difference method on the FLAC3D platform.Comparative analysis of the theoretical,numerical,and experimental results reveals that the fractional-order constitutive model,which incorporates the double damage effect,accurately reflects the distinct deformation stages of green mudstone during creep failure and effectively captures the non-linear deformation in the accelerated creep phase.The numerical results show a fitting accuracy exceeding 97%with the creep test curves,significantly outperforming the 61%accuracy of traditional creep models. 展开更多
关键词 Mining damage Creep damage fractional-order Constitutive model Secondary development
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A novel color image encryption scheme using fractional-order hyperchaotic system and DNA sequence operations 被引量:4
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作者 张立民 孙克辉 +1 位作者 刘文浩 贺少波 《Chinese Physics B》 SCIE EI CAS CSCD 2017年第10期98-106,共9页
In this paper, Adomian decomposition method (ADM) with high accuracy and fast convergence is introduced to solve the fractional-order piecewise-linear (PWL) hyperchaotic system. Based on the obtained hyperchaotic ... In this paper, Adomian decomposition method (ADM) with high accuracy and fast convergence is introduced to solve the fractional-order piecewise-linear (PWL) hyperchaotic system. Based on the obtained hyperchaotic sequences, a novel color image encryption algorithm is proposed by employing a hybrid model of bidirectional circular permutation and DNA masking. In this scheme, the pixel positions of image are scrambled by circular permutation, and the pixel values are substituted by DNA sequence operations. In the DNA sequence operations, addition and substraction operations are performed according to traditional addition and subtraction in the binary, and two rounds of addition rules are used to encrypt the pixel values. The simulation results and security analysis show that the hyperchaotic map is suitable for image encryption, and the proposed encryption algorithm has good encryption effect and strong key sensitivity. It can resist brute-force attack, statistical attack, differential attack, known-plaintext, and chosen-plaintext attacks. 展开更多
关键词 color image encryption DNA sequence operation fractional calculus piecewise-linear hyperchaotic system
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2-complex Symmetric Weighted Composition Operators on Fock Space of C^(N)
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作者 JIANG Zhijie 《数学进展》 北大核心 2025年第1期37-49,共13页
The aim of the present paper is to study 2-complex symmetric bounded weighted composition operators on the Fock space of C^(N) with the conjugations J and J_(t,A,b) defined by ■ respectively,where k(z_(1),...,z_N)=(... The aim of the present paper is to study 2-complex symmetric bounded weighted composition operators on the Fock space of C^(N) with the conjugations J and J_(t,A,b) defined by ■ respectively,where k(z_(1),...,z_N)=(■,...,■),t∈C,b∈C^(N) and A is a linear operator on C^(N).An example of 2-complex symmetric bounded weighted composition operator with the conjugation J_(t,A,b) is given. 展开更多
关键词 Fock space weighted composition operator 2-complex symmetric operator reproducing kernel function
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Global Piecewise Analysis of HIV Model with Bi-Infectious Categories under Ordinary Derivative and Non-Singular Operator with Neural Network Approach
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作者 Ghaliah Alhamzi Badr Saad TAlkahtani +1 位作者 Ravi Shanker Dubey Mati ur Rahman 《Computer Modeling in Engineering & Sciences》 SCIE EI 2025年第1期609-633,共25页
This study directs the discussion of HIV disease with a novel kind of complex dynamical generalized and piecewise operator in the sense of classical and Atangana Baleanu(AB)derivatives having arbitrary order.The HIV i... This study directs the discussion of HIV disease with a novel kind of complex dynamical generalized and piecewise operator in the sense of classical and Atangana Baleanu(AB)derivatives having arbitrary order.The HIV infection model has a susceptible class,a recovered class,along with a case of infection divided into three sub-different levels or categories and the recovered class.The total time interval is converted into two,which are further investigated for ordinary and fractional order operators of the AB derivative,respectively.The proposed model is tested separately for unique solutions and existence on bi intervals.The numerical solution of the proposed model is treated by the piece-wise numerical iterative scheme of Newtons Polynomial.The proposed method is established for piece-wise derivatives under natural order and non-singular Mittag-Leffler Law.The cross-over or bending characteristics in the dynamical system of HIV are easily examined by the aspect of this research having a memory effect for controlling the said disease.This study uses the neural network(NN)technique to obtain a better set of weights with low residual errors,and the epochs number is considered 1000.The obtained figures represent the approximate solution and absolute error which are tested with NN to train the data accurately. 展开更多
关键词 HIV infection model qualitative scheme approximate solution piecewise global operator neural network
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The Characterization of Self-adjoint Domains of Two-interval Odd Order Differential Operators
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作者 WANG Linyu HAO Xiaoling LI Kun 《数学进展》 北大核心 2025年第4期784-802,共19页
In this paper,we give a complete characterization of all self-adjoint domains of odd order differential operators on two intervals.These two intervals with all four endpoints are singular(one endpoint of each interval... In this paper,we give a complete characterization of all self-adjoint domains of odd order differential operators on two intervals.These two intervals with all four endpoints are singular(one endpoint of each interval is singular or all four endpoints are regulars are the special cases).And these extensions yield"new"self-adjoint operators,which involve interactions between the two intervals. 展开更多
关键词 self-adjoint domain odd order differential operator two-interval
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Boundedness of the Commutators of Rough Singular Integral Operators on Triebel–Lizorkin Spaces
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作者 LIU Jie GAO Wenhua 《数学进展》 北大核心 2025年第5期1075-1086,共12页
Let Ω be homogeneous of degree zero,integrable on S^(n−1) and have mean value zero,T_(Ω) be the homogeneous singular integral operator with kernel Ω(x)/|x|^(n) and[b,T_(Ω)]be the commutator of T_(Ω)with symbol b∈BMO(... Let Ω be homogeneous of degree zero,integrable on S^(n−1) and have mean value zero,T_(Ω) be the homogeneous singular integral operator with kernel Ω(x)/|x|^(n) and[b,T_(Ω)]be the commutator of T_(Ω)with symbol b∈BMO(R^(n)).In this paper,the authors prove that if sup ζ∈S^(n−1)∫Sn−1^(|Ω(θ)|log^(β)(1/|θ·ζ|)dθ<∞ with β>2,then[b,T_(Ω)]is bounded on Triebel–Lizorkin space F^(0,q)p(R^(n))provided that 1+1/β−1<p,q<β. 展开更多
关键词 rough singular integral operator COMMUTATOR Triebel-Lizorkin space Littlewood-Paley theory
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Medical Diagnosis Based on Multi-Attribute Group Decision-Making Using Extension Fuzzy Sets,Aggregation Operators and Basic Uncertainty Information Granule
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作者 Anastasios Dounis Ioannis Palaiothodoros Anna Panagiotou 《Computer Modeling in Engineering & Sciences》 SCIE EI 2025年第1期759-811,共53页
Accurate medical diagnosis,which involves identifying diseases based on patient symptoms,is often hindered by uncertainties in data interpretation and retrieval.Advanced fuzzy set theories have emerged as effective to... Accurate medical diagnosis,which involves identifying diseases based on patient symptoms,is often hindered by uncertainties in data interpretation and retrieval.Advanced fuzzy set theories have emerged as effective tools to address these challenges.In this paper,new mathematical approaches for handling uncertainty in medical diagnosis are introduced using q-rung orthopair fuzzy sets(q-ROFS)and interval-valued q-rung orthopair fuzzy sets(IVq-ROFS).Three aggregation operators are proposed in our methodologies:the q-ROF weighted averaging(q-ROFWA),the q-ROF weighted geometric(q-ROFWG),and the q-ROF weighted neutrality averaging(qROFWNA),which enhance decision-making under uncertainty.These operators are paired with ranking methods such as the similarity measure,score function,and inverse score function to improve the accuracy of disease identification.Additionally,the impact of varying q-rung values is explored through a sensitivity analysis,extending the analysis beyond the typical maximum value of 3.The Basic Uncertain Information(BUI)method is employed to simulate expert opinions,and aggregation operators are used to combine these opinions in a group decisionmaking context.Our results provide a comprehensive comparison of methodologies,highlighting their strengths and limitations in diagnosing diseases based on uncertain patient data. 展开更多
关键词 Medical diagnosis multi-attribute group decision-making(MAGDM) q-ROFS IVq-ROFS BUI aggregation operators similarity measures inverse score function
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Size-dependent bending and vibration analysis of piezoelectric nanobeam based on fractional-order kinematic relations
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作者 Zhiwen FAN Hai QING 《Applied Mathematics and Mechanics(English Edition)》 2025年第7期1261-1272,I0003-I0011,共21页
In this paper,a fractional-order kinematic model is utilized to capture the size-dependent static bending and free vibration responses of piezoelectric nanobeams.The general nonlocal strains in the Euler-Bernoulli pie... In this paper,a fractional-order kinematic model is utilized to capture the size-dependent static bending and free vibration responses of piezoelectric nanobeams.The general nonlocal strains in the Euler-Bernoulli piezoelectric beam are defined by a frame-invariant and dimensionally consistent Riesz-Caputo fractional-order derivatives.The strain energy,the work done by external loads,and the kinetic energy based on the fractional-order kinematic model are derived and expressed in explicit forms.The boundary conditions for the nonlocal Euler-Bernoulli beam are derived through variational principles.Furthermore,a finite element model for the fractional-order system is developed in order to obtain the numerical solutions to the integro-differential equations.The effects of the fractional order and the vibration order on the static bending and vibration responses of the Euler-Bernoulli piezoelectric beams are investigated numerically.The results from the present model are validated against the existing results in the literature,and it is demonstrated that they are theoretically consistent.Although this fractional finite element method(FEM)is presented in the context of a one-dimensional(1D)beam,it can be extended to higher dimensional fractional-order boundary value problems. 展开更多
关键词 scale effect Riesz-Caputo fractional-order derivative Euler-Bernoulli piezoelectric beam fractional-order¯nite element method(FEM)
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Effects of potential field delay and coupling delay on collective behavior of a fractional-order coupled system in a dichotomous fluctuating potential
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作者 Yangfan Zhong Xi Chen +1 位作者 Maokang Luo Tao Yu 《Chinese Physics B》 2025年第5期270-287,共18页
The collective dynamic of a fractional-order globally coupled system with time delays and fluctuating frequency is investigated.The power-law memory of the system is characterized using the Caputo fractional derivativ... The collective dynamic of a fractional-order globally coupled system with time delays and fluctuating frequency is investigated.The power-law memory of the system is characterized using the Caputo fractional derivative operator.Additionally,time delays in the potential field force and coupling force transmission are both considered.Firstly,based on the delay decoupling formula,combined with statistical mean method and the fractional-order Shapiro–Loginov formula,the“statistic synchronization”among particles is obtained,revealing the statistical equivalence between the mean field behavior of the system and the behavior of individual particles.Due to the existence of the coupling delay,the impact of the coupling force on synchronization exhibits non-monotonic,which is different from the previous monotonic effects.Then,two kinds of theoretical expression of output amplitude gains G and G are derived by time-delay decoupling formula and small delay approximation theorem,respectively.Compared to G,G is an exact theoretical solution,which means that G is not only more accurate in the region of small delay,but also applies to the region of large delay.Finally,the study of the output amplitude gain G and its resonance behavior are explored.Due to the presence of the potential field delay,a new resonance phenomenon termed“periodic resonance”is discovered,which arises from the periodic matching between the potential field delay and the driving frequency.This resonance phenomenon is analyzed qualitatively and quantitatively,uncovering undiscovered characteristics in previous studies. 展开更多
关键词 potential field delay coupling delay fractional-order collective behavior
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A Hybrid Machine Learning and Fractional-Order Dynamical Framework for Multi-Scale Prediction of Breast Cancer Progression
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作者 David Amilo Khadijeh Sadri +1 位作者 Evren Hincal Mohamed Hafez 《Computer Modeling in Engineering & Sciences》 2025年第11期2189-2222,共34页
Breast cancer’s heterogeneous progression demands innovative tools for accurate prediction.We present a hybrid framework that integrates machine learning(ML)and fractional-order dynamics to predict tumor growth acros... Breast cancer’s heterogeneous progression demands innovative tools for accurate prediction.We present a hybrid framework that integrates machine learning(ML)and fractional-order dynamics to predict tumor growth across diagnostic and temporal scales.On the Wisconsin Diagnostic Breast Cancer dataset,seven ML algorithms were evaluated,with deep neural networks(DNNs)achieving the highest accuracy(97.72%).Key morphological features(area,radius,texture,and concavity)were identified as top malignancy predictors,aligning with clinical intuition.Beyond static classification,we developed a fractional-order dynamical model using Caputo derivatives to capture memory-driven tumor progression.The model revealed clinically interpretable patterns:lower fractional orders correlated with prolonged aggressive growth,while higher orders indicated rapid stabilization,mimicking indolent subtypes.Theoretical analyses were rigorously proven,and numerical simulations closely fit clinical data.The framework’s clinical utility is demonstrated through an interactive graphics user interface(GUI)that integrates real-time risk assessment with growth trajectory simulations. 展开更多
关键词 Machine learning fractional-order breast cancer physiological dynamics maternal health preventable deaths
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A New Fuzzy Number Similarity Measure Based on Quadratic-Mean Operator for Handling Fuzzy Recommendation Problems
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作者 Shijay Chen 《Journal of Computer and Communications》 2025年第1期108-124,共17页
This study presents a new approach that advances the algorithm of similarity measures between generalized fuzzy numbers. Following a brief introduction to some properties of the proposed method, a comparative analysis... This study presents a new approach that advances the algorithm of similarity measures between generalized fuzzy numbers. Following a brief introduction to some properties of the proposed method, a comparative analysis based on 36 sets of generalized fuzzy numbers was performed, in which the degree of similarity of the fuzzy numbers was calculated with the proposed method and seven methods established by previous studies in the literature. The results of the analytical comparison show that the proposed similarity outperforms the existing methods by overcoming their drawbacks and yielding accurate outcomes in all calculations of similarity measures under consideration. Finally, in a numerical example that involves recommending cars to customers based on a nine-member linguistic term set, the proposed similarity measure proves to be competent in addressing fuzzy number recommendation problems. 展开更多
关键词 Quadratic-Mean operator Generalized Fuzzy Numbers Similarity Measures Fuzzy Number Recommendation
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COMPACT LINEAR COMBINATIONS OF COMPOSITION OPERATORS ON THE UNIT BALL
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作者 Chunyu DONG Xin GUO Qijian KANG 《Acta Mathematica Scientia》 2025年第3期809-824,共16页
Recently,Choe-Koo-Wang(J Funct Anal,2020,278)demonstrated the rigid phenomenon:The compact linear combination of composition operators under the Coefficient Non-cancellation Condition(CNC),implies that each difference... Recently,Choe-Koo-Wang(J Funct Anal,2020,278)demonstrated the rigid phenomenon:The compact linear combination of composition operators under the Coefficient Non-cancellation Condition(CNC),implies that each difference is compact on the weighted Bergman space in the unit disk.Motivated by the subtle connection of composition operator theory on the weighted Bergman spaces,Korenblum spaces and bounded holomorphic function spaces,we first explore the rigid phenomenon which also holds on the Korenblum space over the unit ball.Furthermore,we discuss which difference of composition operators is compact when the compact combination of composition operators does not satisfy the condition(CNC)on Korenblum spaces and bounded holomorphic function spaces over the unit ball setting. 展开更多
关键词 composition operator linear combination compact operator weighted Bergman space Korenblum space
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A NEW PROOF OF THE WEAK(1,n/n-a)INEQUALITY FOR THE FRACTIONAL MAXIMAL OPERATORS
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作者 WANG Jie 《数学杂志》 2025年第3期213-217,共5页
In this paper,we provide an alternative proof of the weak type(1,n/n-a)inequality for the fractional maximal operators.By using the discretization technique,we can get the main result,which shows that the weak type(1,... In this paper,we provide an alternative proof of the weak type(1,n/n-a)inequality for the fractional maximal operators.By using the discretization technique,we can get the main result,which shows that the weak type(1,n/n-a)bound of M_(α)is at worst 2^(n-a).The weak type(1,n/n-a)bound of M_(α)can be estimated more directly and easily in this method,which is different from the usual ways. 展开更多
关键词 Hardy-Littlewood maximal operator fractional maximal operators Dirac deltas discrete method
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ASYMPTOTIC PROPERTIES OF THE INTEGRATED DENSITY OF STATES FOR RANDOM SCHRÖDINGER OPERATORS
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作者 Longteng ZHANG Jin CHEN 《Acta Mathematica Scientia》 2025年第5期2251-2263,共13页
Explicit asymptotic properties of the integrated density of states N(λ)with respect to the spectrum for the random Schrödinger operator H^(ω)=(-△)^(α/2)+V^(ω)are established,whereα∈(0,2]and V^(ω)(X)=∑_(I... Explicit asymptotic properties of the integrated density of states N(λ)with respect to the spectrum for the random Schrödinger operator H^(ω)=(-△)^(α/2)+V^(ω)are established,whereα∈(0,2]and V^(ω)(X)=∑_(I∈Z^(d))ξ(i)(ω)W(x-i)is a random potential term generated by a sequence of independent and identically distributed random variables{ξ(i)}_(i)∈Z^(d)and a non-negative measurable function W(x).In particular,the exact order of asymptotic properties of N(λ)depends on the decay properties of the reference function W(x)and the spectrum properties of the first Dirichlet eigenvalue of(-△)^(α/2). 展开更多
关键词 ntegrated density of states random Schrodinger operator fractional Laplace operator potential Dirichlet eigenvalue
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High-speed train cooperativecontrol based on fractional-ordersliding mode adaptive algorithm 被引量:2
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作者 Junting Lin Mingjun Ni Huadian Liang 《Railway Sciences》 2023年第1期84-100,共17页
Purpose–This study aims to propose an adaptive fractional-order sliding mode controller to solve the problem of train speed tracking control and position interval control under disturbance environment in moving block... Purpose–This study aims to propose an adaptive fractional-order sliding mode controller to solve the problem of train speed tracking control and position interval control under disturbance environment in moving block system,so as to improve the tracking efficiency and collision avoidance performance.Design/methodology/approach–The mathematical model of information interaction between trains is established based on algebraic graph theory,so that the train can obtain the state information of adjacent trains,and then realize the distributed cooperative control of each train.In the controller design,the sliding mode control and fractional calculus are combined to avoid the discontinuous switching phenomenon,so as to suppress the chattering of sliding mode control,and a parameter adaptive law is constructed to approximate the time-varying operating resistance coefficient.Findings–The simulation results show that compared with proportional integral derivative(PID)control and ordinary sliding mode control,the control accuracy of the proposed algorithm in terms of speed is,respectively,improved by 25%and 75%.The error frequency and fluctuation range of the proposed algorithm are reduced in the position error control,the error value tends to 0,and the operation trend tends to be consistent.Therefore,the control method can improve the control accuracy of the system and prove that it has strong immunity.Originality/value–The algorithm can reduce the influence of external interference in the actual operating environment,realize efficient and stable tracking of trains,and ensure the safety of train control. 展开更多
关键词 High-speed trains Sliding mode control fractional-order differentiation Adaptive law Cooperative control
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Approximation by modified Durrmeyer type Jakimovski-Leviatan operators
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作者 Qing-bo Cai Şule Yüksel Güngör +1 位作者 BayramÇekim Mehmet AliÖzarslan 《Applied Mathematics(A Journal of Chinese Universities)》 2025年第3期709-724,共16页
In the present paper,the modified Durrmeyer type Jakimovski-Leviatan operators are presented and their approximation properties are examined.It has shown that the new operators are the Gamma transform of the Jakimovsk... In the present paper,the modified Durrmeyer type Jakimovski-Leviatan operators are presented and their approximation properties are examined.It has shown that the new operators are the Gamma transform of the Jakimovski-Leviatan operators.The degree of approximation is given by the modulus of continuity.It has been stressed that,there are other operators having the same error estimation with the operators,arising from the Sz´asz-Durrmeyer operators.Then the degree of global approximation is obtained in a special Lipschitz type function space.Further,a Voronovskaja type asymptotic formula and Gr¨uss-Voronovskaja type theorem are given.The approximation with these operators is visualized with the help of error tables and graphical examples. 展开更多
关键词 modulus of continuity Appell polynomials Durrmeyer operators Jakimovski-Leviatan operators Lipschitz type function space
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Enhanced Fractional-Order Nonsingular Terminal Sliding Mode Control for Fully Submerged Hydrofoil Craft with Actuator Saturation
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作者 Hongmin Niu Shiquan Zhao +1 位作者 Cristina IMuresan Clara Mihaela Ionescu 《哈尔滨工程大学学报(英文版)》 2025年第6期1264-1278,共15页
This study introduces an enhanced adaptive fractional-order nonsingular terminal sliding mode controller(AFONTSMC)tailored for stabilizing a fully submerged hydrofoil craft(FSHC)under external disturbances,model uncer... This study introduces an enhanced adaptive fractional-order nonsingular terminal sliding mode controller(AFONTSMC)tailored for stabilizing a fully submerged hydrofoil craft(FSHC)under external disturbances,model uncertainties,and actuator saturation.A novel nonlinear disturbance observer modified by fractional-order calculus is proposed for flexible and less conservative estimation of lumped disturbances.An enhanced adaptive fractional-order nonsingular sliding mode scheme augmented by disturbance estimation is also introduced to improve disturbance rejection.This controller design only necessitates surpassing the estimation error rather than adhering strictly to the disturbance upper bound.Additionally,an adaptive fast-reaching law with a hyperbolic tangent function is incorporated to enhance the responsiveness and convergence rates of the controller,thereby reducing chattering.Furthermore,an auxiliary actuator compensator is developed to address saturation effects.The resultant closed system of the FSHC with the designed controller is globally asymptotically stable. 展开更多
关键词 Fully submerged hydrofoil craft Longitudinal motion control fractional-order terminal sliding mode control Disturbance observer Saturation compensation
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