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Nonlocal Boundary Value Problems for Nonlinear Fractional Differential Equations with a Disturbance Parameter on the Infinite Interval
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作者 ZHENG Yanping YANG Hui WANG Wenxia 《应用数学》 北大核心 2026年第2期360-372,共13页
This paper is concerned with a class of nonlinear fractional differential equations with a disturbance parameter in the integral boundary conditions on the infinite interval.By using Guo-Krasnoselskii fixed point theo... This paper is concerned with a class of nonlinear fractional differential equations with a disturbance parameter in the integral boundary conditions on the infinite interval.By using Guo-Krasnoselskii fixed point theorem,fixed point index theory and the analytic technique,we give the bifurcation point of the parameter which divides the range of parameter for the existence of at least two,one and no positive solutions for the problem.And,by using a fixed point theorem of generalized concave operator and cone theory,we establish the maximum parameter interval for the existence of the unique positive solution for the problem and show that such a positive solution continuously depends on the parameter.In the end,some examples are given to illustrate our main results. 展开更多
关键词 boundary value problem Disturbance parameter Infinite interval Bifurcation point CONE
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NONLINEAR RIEMANN AND HILBERT BOUNDARY VALUE PROBLEMS WITH SQUARE ROOTS IN VARIABLE EXPONENT SPACES
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作者 Yajun Hu Fuli He 《Acta Mathematica Scientia》 2026年第1期1-18,共18页
In this paper,we study the nonlinear Riemann boundary value problem with square roots that is represented by a Cauchy-type integral with kernel density in variable exponent Lebesgue spaces.We discuss the odd-order zer... In this paper,we study the nonlinear Riemann boundary value problem with square roots that is represented by a Cauchy-type integral with kernel density in variable exponent Lebesgue spaces.We discuss the odd-order zero-points distribution of the solutions and separate the single valued analytic branch of the solutions with square roots,then convert the problem to a Riemann boundary value problem in variable exponent Lebesgue spaces and discuss the singularity of solutions at individual zeros belonging to curve.We consider two types of cases those where the coefficient is Hölder and those where it is piecewise Hölder.Then we solve the Hilbert boundary value problem with square roots in variable exponent Lebesgue spaces.By discussing the distribution of the odd-order zero-points for solutions and the method of symmetric extension,we convert the Hilbert problem to a Riemann boundary value problem.The equivalence of the transformation is discussed.Finally,we get the solvable conditions and the direct expressions of the solutions in variable exponent Lebesgue spaces. 展开更多
关键词 boundary value problem Cauchy-type integral variable exponent spaces non-linearity piecewise Lyapunov curve
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Neural boundary shape functions in physics-informed neural networks for discontinuous and high-frequency problems
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作者 P.T.NGUYEN K.A.LUONG J.H.LEE 《Applied Mathematics and Mechanics(English Edition)》 2026年第2期423-442,共20页
Physics-informed neural networks(PINNs)have been shown as powerful tools for solving partial differential equations(PDEs)by embedding physical laws into the network training.Despite their remarkable results,complicate... Physics-informed neural networks(PINNs)have been shown as powerful tools for solving partial differential equations(PDEs)by embedding physical laws into the network training.Despite their remarkable results,complicated problems such as irregular boundary conditions(BCs)and discontinuous or high-frequency behaviors remain persistent challenges for PINNs.For these reasons,we propose a novel two-phase framework,where a neural network is first trained to represent shape functions that can capture the irregularity of BCs in the first phase,and then these neural network-based shape functions are used to construct boundary shape functions(BSFs)that exactly satisfy both essential and natural BCs in PINNs in the second phase.This scheme is integrated into both the strong-form and energy PINN approaches,thereby improving the quality of solution prediction in the cases of irregular BCs.In addition,this study examines the benefits and limitations of these approaches in handling discontinuous and high-frequency problems.Overall,our method offers a unified and flexible solution framework that addresses key limitations of existing PINN methods with higher accuracy and stability for general PDE problems in solid mechanics. 展开更多
关键词 physics-informed neural network(PINN) boundary shape function(BSF) strong-form approach energy approach DISCONTINUITY high-frequency problem
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Existence Results of Third Order Multi-Point Boundary Value Problem at Resonance 被引量:3
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作者 杜增吉 白占兵 葛渭高 《Journal of Beijing Institute of Technology》 EI CAS 2005年第4期449-452,共4页
A kind of third order multi-point boundary value problems, x'''( ι) = f( t, x ( t ), x" ( t ), x''' ( t ) ) + m 2 e(t),t∈(0, 1),x(0)=ax(ξ),x'(0)-0,x(l)= ^m2∑j=1 βjx(ηj), fεC[0,... A kind of third order multi-point boundary value problems, x'''( ι) = f( t, x ( t ), x" ( t ), x''' ( t ) ) + m 2 e(t),t∈(0, 1),x(0)=ax(ξ),x'(0)-0,x(l)= ^m2∑j=1 βjx(ηj), fεC[0, 1]×R^3, e(t)∈L^1[0, 1],a≥0, is considered, all theβj's have not the same sign, 0〈ξ〈 l, 0〈η1〈 η2〈… 〈ηm.2〈 1. By using the coincidence degree theory, some existence theorems for the problems at resonance are obtained. 展开更多
关键词 multi-point boundary value problem RESONANCE coincidence degree theory
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SOLUTIONS TO A SECOND-ORDER MULTI-POINT BOUNDARY VALUE PROBLEM AT RESONANCE 被引量:2
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作者 杜增吉 孟凡超 《Acta Mathematica Scientia》 SCIE CSCD 2010年第5期1567-1576,共10页
This article deals with the following second-order multi-point boundary value problem x″(t)=r(t,x(t),x′(t))+e(t),t∈(0,1)x′(0)=m∑i=1aix′(ξi),x(1)=n∑j=1βjx(ηj), Under the resonance conditi... This article deals with the following second-order multi-point boundary value problem x″(t)=r(t,x(t),x′(t))+e(t),t∈(0,1)x′(0)=m∑i=1aix′(ξi),x(1)=n∑j=1βjx(ηj), Under the resonance conditions m∑i=1ai=1,n∑j=1βj=1,n∑j=1βjηj=1 , by applying the coincidence degree theory, some existence results of the problem are established. The emphasis here is that the dimension of the linear operator is two. In this paper, we extend and improve some previously known results like the ones in the references. 展开更多
关键词 coincidence degree multi-point boundary value problem RESONANCE
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The Existence of Solutions to a Class of Multi-point Boundary Value Problem of Fractional Differential Equation 被引量:2
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作者 Xiaohong HAO Zongfu ZHOU 《Journal of Mathematical Research with Applications》 CSCD 2013年第2期175-188,共14页
In this paper, we consider the following multi-point boundary value problem of fractional differential equation D^α0+u(t)=f(t,u(t),D^α-10+u(t),D^α-20+u(t),D^α-30+u(t),t∈(0,1),I^4-α0+u(0)=0,D^... In this paper, we consider the following multi-point boundary value problem of fractional differential equation D^α0+u(t)=f(t,u(t),D^α-10+u(t),D^α-20+u(t),D^α-30+u(t),t∈(0,1),I^4-α0+u(0)=0,D^α-10+u(t)=^n∑i=1αiD^α-10+u(ξ1),D^α-20+u(1)=^n∑j=1D^α-20+u(ηj),D^α-30+u(1)-D^α-30+u(0)=D^α-20+u(1/2),where 3 〈 α ≤ 4 is a real number. By applying Mawhin coincidence degree theory and constructing suitable operators, some existence results of solutions can be established. 展开更多
关键词 fractional differential equation multi-point boundary value problem coincidencedegree
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EXISTENCE OF SOLUTIONS FOR HIGHER ORDER MULTI-POINT BOUNDARY VALUE PROBLEM AT RESONANCE 被引量:3
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作者 林晓洁 杜增吉 葛渭高 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI 2006年第5期705-711,共7页
Using the theory of coincidence degree, a class of higher order multi-point boundary value problem for ordinary differential equations are studied. Under the boundary conditions satisfying the resonance case, some new... Using the theory of coincidence degree, a class of higher order multi-point boundary value problem for ordinary differential equations are studied. Under the boundary conditions satisfying the resonance case, some new existence results are obtained by supposing some conditions to the nonlinear term and applying a priori estimates. 展开更多
关键词 boundary value problem RESONANCE coincidence degree theory
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Multiple Positive Solutions for Multi-Point Boundary Value Problem of Fractional Differential Equation 被引量:1
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作者 Xiping LIU Mei JIA +1 位作者 Ming NIU Xiufen XIANG 《Journal of Mathematical Research with Applications》 CSCD 2017年第2期223-232,共10页
In this paper, we study the multiplicity of positive solutions for multi-point boundary value problem of Riemann-Liouville fractional differential equation with multi-terms fractional derivative in the boundary condit... In this paper, we study the multiplicity of positive solutions for multi-point boundary value problem of Riemann-Liouville fractional differential equation with multi-terms fractional derivative in the boundary conditions. By using the properties of the Green function and a generalization of the Leggett-Williams fixed point theorem due to the work of Bai and Ge, the sufficient conditions to guarantee the existence of at least three positive solutions are established. In the end of this paper, we have also given out the example to illustrate the wide range of potential application of our main results. 展开更多
关键词 fractional differential equation multi-point boundary value problem POSITIVESOLUTION Green function fixed point theorem
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Existence and Uniqueness of Solutions for Higher Order Nonlinear Multi-point Boundary Value Problems 被引量:7
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作者 PEI Ming-he Sung-Kag Chang 《Chinese Quarterly Journal of Mathematics》 CSCD 2009年第2期258-266,共9页
In this paper, the existence and uniqueness theorems of solutions of k-point boundary value problems for nth-order nonlinear differential equations are established by Leray-Schauder continuation theorem.
关键词 nth-order nonlinear differential equations k-point boundary value problem EXISTENCE UNIQUENESS
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SOME NECESSARY AND SUFFICIENT CONDITIONS FOR EXISTENCE OF POSITIVE SOLUTIONS FOR THIRD ORDER SINGULAR SUBLINEAR MULTI-POINT BOUNDARY VALUE PROBLEMS 被引量:5
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作者 韦忠礼 《Acta Mathematica Scientia》 SCIE CSCD 2014年第6期1795-1810,共16页
We mainly study the existence of positive solutions for the following third order singular multi-point boundary value problem{x^(3)(t) + f(t, x(t), x′(t)) = 0, 0 〈 t 〈 1,x(0)-∑i=1^m1 αi x(ξi) = 0... We mainly study the existence of positive solutions for the following third order singular multi-point boundary value problem{x^(3)(t) + f(t, x(t), x′(t)) = 0, 0 〈 t 〈 1,x(0)-∑i=1^m1 αi x(ξi) = 0, x′(0)-∑i=1^m2 βi x′(ηi) = 0, x′(1)=0,where 0 ≤ ai≤∑i=1^m1 αi 〈 1, i = 1, 2, ···, m1, 0 〈 ξ1〈 ξ2〈 ··· 〈 ξm1〈 1, 0 ≤βj≤∑i^m2=1βi〈1,J=1,2, ···, m2, 0 〈 η1〈 η2〈 ··· 〈 ηm2〈 1. And we obtain some necessa βi 〈=11, j = 1,ry and sufficient conditions for the existence of C^1[0, 1] and C^2[0, 1] positive solutions by constructing lower and upper solutions and by using the comparison theorem. Our nonlinearity f(t, x, y)may be singular at x, y, t = 0 and/or t = 1. 展开更多
关键词 boundary value problems positive solutions lower and upper solutions comparison theorem
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Existence of Positive Solutions for a Third-Order Multi-Point Boundary Value Problem 被引量:2
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作者 A. Guezane-Lakoud L. Zenkoufi 《Applied Mathematics》 2012年第9期1008-1013,共6页
By using Leray-Schauder nonlinear alternative, Banach contraction theorem and Guo-Krasnosel’skii theorem, we discuss the existence, uniqueness and positivity of solution to the third-order multi-point nonhomogeneous ... By using Leray-Schauder nonlinear alternative, Banach contraction theorem and Guo-Krasnosel’skii theorem, we discuss the existence, uniqueness and positivity of solution to the third-order multi-point nonhomogeneous boundary value problem (BVP1): where for The interesting point lies in the fact that the nonlinear term is allowed to depend on the first order derivative . 展开更多
关键词 Guo’s Fixed POINT THEOREM Three POINT boundary Value problem Positive Solution LERAY SCHAUDER Non-Linear Alternative CONTRACTION Principle
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Positive Solutions for Fractional Differential Equations with Multi-Point Boundary Value Problems 被引量:1
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作者 Lina Zhou Weihua Jiang 《Journal of Applied Mathematics and Physics》 2014年第5期108-114,共7页
In this paper, a fractional multi-point boundary value problem is considered. By using the fixed point index theory and Krein-Rutman theorem, some results on existence are obtained.
关键词 Caputo FRACTIONAL DERIVATIVE FRACTIONAL INTEGRAL boundary VALUE problem Fixed Point Index Theory
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Multi-point Boundary Value Problems for Nonlinear Fourth-order Differential Equations with All Order Derivatives
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作者 Yang Liu Shi Shao-yun 《Communications in Mathematical Research》 CSCD 2013年第2期108-120,共13页
By using fixed point theorem, multiple positive solutions for some fourth- order multi-point boundary value problems with nonlinearity depending on all order derivatives are obtained. The associated Green's functions... By using fixed point theorem, multiple positive solutions for some fourth- order multi-point boundary value problems with nonlinearity depending on all order derivatives are obtained. The associated Green's functions are also given. 展开更多
关键词 multi-point boundary value problem positive solution CONE fixed point
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Direct and Inverse Problems for a Third-order Differential Operator with Anti-periodic Boundary Conditions and a Non-local Potential
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作者 ZHANG Mingming LIU Yixuan 《数学理论与应用》 2025年第1期62-80,共19页
This paper focuses on the direct and inverse problems for a third-order self-adjoint differential operator with non-local potential and anti-periodic boundary conditions.Firstly,we obtain the expressions for the chara... This paper focuses on the direct and inverse problems for a third-order self-adjoint differential operator with non-local potential and anti-periodic boundary conditions.Firstly,we obtain the expressions for the characteristic function and resolvent of this third-order differential operator.Secondly,by using the expression for the resolvent of the operator,we prove that the spectrum for this operator consists of simple eigenvalues and a finite number of eigenvalues with multiplicity 2.Finally,we solve the inverse problem for this operator,which states that the non-local potential function can be reconstructed from four spectra.Specially,we prove the Ambarzumyan theorem and indicate that odd or even potential functions can be reconstructed by three spectra. 展开更多
关键词 Direct problem Inverse problem Non-local potential Anti-periodic boundary condition
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Green’s Functions of a Class of Sturm-Liouville Problems with Eigenparameters in Boundary Conditions
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作者 XIAO Lu MU Dan ZHANG Ruifan 《数学理论与应用》 2025年第1期94-106,共13页
In this paper,we study a class of Sturm-Liouville problems,where the boundary conditions involve eigenparameters.Firstly,by defining a new inner product which depends on the transmission conditions,we obtain a new Hil... In this paper,we study a class of Sturm-Liouville problems,where the boundary conditions involve eigenparameters.Firstly,by defining a new inner product which depends on the transmission conditions,we obtain a new Hilbert space,on which the concerned operator A is self-adjoint.Then we construct the fundamental solutions to the problem,obtain the necessary and sufficient conditions for eigenvalues,and prove that the eigenvalues are simple.Finally,we investigate Green’s functions of such problem. 展开更多
关键词 Sturm-Liouville problem Eigenparameter-dependent boundary condition Green’s function
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EXISTENCE OF LARGE BOUNDARY LAYER SOLUTIONS TO INFLOW PROBLEM OF 1D FULL COMPRESSIBLE NAVIER-STOKES EQUATIONS
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作者 Yi WANG Yongfu YANG Qiuyang YU 《Acta Mathematica Scientia》 2025年第6期2591-2606,共16页
We present the existence/non-existence criteria for large-amplitude boundary layer solutions to the inflow problem of the one-dimensional(1D)full compressible NavierStokes equations on a half line R_+.Instead of the c... We present the existence/non-existence criteria for large-amplitude boundary layer solutions to the inflow problem of the one-dimensional(1D)full compressible NavierStokes equations on a half line R_+.Instead of the classical center manifold approach for the existence of small-amplitude boundary layer solutions in the previous results,the delicate global phase plane analysis,based on the qualitative theory of ODEs,is utilized to obtain the sufficient and necessary conditions for the existence/non-existence of large boundary layer solutions to the half-space inflow problem when the right end state belongs to the supersonic,transonic,and subsonic regions,respectively,which completely answers the existence/nonexistence of boundary layer solutions to the half-space inflow problem of 1D full compressible Navier-Stokes equations. 展开更多
关键词 compressible Navier-Stokes equations inflow problem large-amplitude boundary layer solutions
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Ambrosetti-Prodi Type Results for the Discrete Boundary Value Problems Involving the Singularφ-Laplacian
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作者 Yanyun LI Man XU 《Journal of Mathematical Research with Applications》 2025年第6期773-788,共16页
In this paper,we consider the discrete boundary value problem of the type{∆u1=0=∆un-1,∇(t_(k)^(N-1))φ(∆uk))+t_(k)^(N-1)fk(t_(k),u_(k),∆_(uk))=0,2≤k≤n-1,whereφ:(-a,a)→R,0<a<∞,is an increasing homeomorphism ... In this paper,we consider the discrete boundary value problem of the type{∆u1=0=∆un-1,∇(t_(k)^(N-1))φ(∆uk))+t_(k)^(N-1)fk(t_(k),u_(k),∆_(uk))=0,2≤k≤n-1,whereφ:(-a,a)→R,0<a<∞,is an increasing homeomorphism withφ(0)=0,such aφis called singular,N≥1,n≥3 are integers,tk are the grid points,uk:=u(tk),k=1,2,...,n,∇is the backward difference operator defined by∆uk=uk-uk-1,△is the forward difference operator defined by△uk=uk+1-uk,fk(2≤k≤n-1)are continuous functions.We prove the existence of solutions to this problem by employing the sign condition,the continuation lemma and the upper and lower solutions,respectively.On this basis,we also establish the Ambrosetti-Prodi type results for it. 展开更多
关键词 singularφ-Laplacian discrete boundary value problem EXISTENCE Ambrosetti-Prodi type results lower and upper solutions topological degree
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Existence of Solution to Multi-Point Boundary Value Problems at Resonance
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作者 薛春艳 高晶 葛渭高 《Journal of Beijing Institute of Technology》 EI CAS 2005年第2期203-207,共5页
A class of second order multi-point boundary value problem at resonance is considered. Under some appropriate conditions, the existence of solutions to the nonlinear problem is obtained by use of the coincidence degre... A class of second order multi-point boundary value problem at resonance is considered. Under some appropriate conditions, the existence of solutions to the nonlinear problem is obtained by use of the coincidence degree theory of Mawhin. 展开更多
关键词 boundary value problem (BVP) Fredholm operator RESONANCE
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A Compact Difference Scheme for Multi-point Boundary Value Problems of Heat Equations
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作者 Xuping Wang Zhizhong Sun 《Communications on Applied Mathematics and Computation》 2019年第4期545-563,共19页
In this paper,a compact difference scheme is established for the heat equations with multi-point boundary value conditions.The truncation error of the difference scheme is O(τ2+h^4),where t and h are the temporal ste... In this paper,a compact difference scheme is established for the heat equations with multi-point boundary value conditions.The truncation error of the difference scheme is O(τ2+h^4),where t and h are the temporal step size and the spatial step size.A prior estimate of the difference solution in a weighted norm is obtained.The unique solvability,stability and convergence of the difference scheme are proved by the energy method.The theoretical statements for the solution of the difference scheme are supported by numerical examples. 展开更多
关键词 Heat EQUATION - multi-point boundary VALUE CONDITION COMPACT DIFFERENCE scheme Energy method
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Existence of Solutions for a Multi-point Boundary Value Problems with Three Dimension Kernal at Resonance
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作者 LIANG Ju-hua REN Li-shun ZHAO Zhi-liang 《Chinese Quarterly Journal of Mathematics》 CSCD 2011年第1期138-143,共6页
In this paper,a multi-point boundary value problems for a three order nonlinear deferential equation is considered.With the help of coincidence theorem due to Mawhin,a existence theorem is obtained.
关键词 boundary value problems coincidence degree theorem existence theorem 2000 MR Subject Classification:34B10 34B15
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