We consider a strongly non-linear degenerate parabolic-hyperbolic problem with p(x)-Laplacian diffusion flux function. We propose an entropy formulation and prove the existence of an entropy solution.
We provide a kernel-regularized method to give theory solutions for Neumann boundary value problem on the unit ball. We define the reproducing kernel Hilbert space with the spherical harmonics associated with an inner...We provide a kernel-regularized method to give theory solutions for Neumann boundary value problem on the unit ball. We define the reproducing kernel Hilbert space with the spherical harmonics associated with an inner product defined on both the unit ball and the unit sphere, construct the kernel-regularized learning algorithm from the view of semi-supervised learning and bound the upper bounds for the learning rates. The theory analysis shows that the learning algorithm has better uniform convergence according to the number of samples. The research can be regarded as an application of kernel-regularized semi-supervised learning.展开更多
In this paper,a fractional Laplacian mutualistic system under Neumann boundary conditions is studied.Using the method of upper and lower solutions,it is proven that the solutions of the fractional Laplacian strong mut...In this paper,a fractional Laplacian mutualistic system under Neumann boundary conditions is studied.Using the method of upper and lower solutions,it is proven that the solutions of the fractional Laplacian strong mutualistic model with Neumann boundary conditions will blow up when the intrinsic growth rates of species are large.展开更多
This paper deals with the blow-up properties of solutions to semilinear heat equation ut-uxx= up in (0, 1) × (0, T) with the Neumann boundary condition ux(0, t) = 0, u:x1, t) = 1 on [0, T). The necessary and suff...This paper deals with the blow-up properties of solutions to semilinear heat equation ut-uxx= up in (0, 1) × (0, T) with the Neumann boundary condition ux(0, t) = 0, u:x1, t) = 1 on [0, T). The necessary and sufficient conditions under which all solutions to have a finite time blow-up and the exact blow-up rates are established. It is proved that the blow-up will occur only at the boundary x = 1. The asymptotic behavior near the blow-up time is also studied.展开更多
An iterative direct-forcing immersed boundary method is extended and used to solve convection heat transfer problems.The pressure,momentum source,and heat source at immersed boundary points are calculated simultaneous...An iterative direct-forcing immersed boundary method is extended and used to solve convection heat transfer problems.The pressure,momentum source,and heat source at immersed boundary points are calculated simultaneously to achieve the best coupling.Solutions of convection heat transfer problems with both Dirichlet and Neumann boundary conditions are presented.Two approaches for the implementation of Neumann boundary condition,i.e.direct and indirect methods,are introduced and compared in terms of accuracy and computational efficiency.Validation test cases include forced convection on a heated cylinder in an unbounded flow field and mixed convection around a circular body in a lid-driven cavity.Furthermore,the proposed method is applied to study the mixed convection around a heated rotating cylinder in a square enclosure with both iso-heat flux and iso-thermal boundary conditions.Computational results show that the order of accuracy of the indirect method is less than the direct method.However,the indirect method takes less computational time both in terms of the implementation of the boundary condition and the post processing time required to compute the heat transfer variables such as the Nusselt number.It is concluded that the iterative direct-forcing immersed boundary method is a powerful technique for the solution of convection heat transfer problems with stationary/moving boundaries and various boundary conditions.展开更多
In this work we show that homogeneous Neumann boundary conditions inhibit the Coleman-Weinberg mechanism for spontaneous symmetry breaking in the scalar electrodynamics if the length of the finite region is small enou...In this work we show that homogeneous Neumann boundary conditions inhibit the Coleman-Weinberg mechanism for spontaneous symmetry breaking in the scalar electrodynamics if the length of the finite region is small enough (a = e2Mφ-1, where M, is the mass of the scalar field generated by the Coleman-Weinberg mechanism).展开更多
We establish an extension result of existence and partial regularity for the nonzero Neumann initial-boundary value problem of the Landau-Lifshitz equation with nonpositive anisotropy constants in three or four dimens...We establish an extension result of existence and partial regularity for the nonzero Neumann initial-boundary value problem of the Landau-Lifshitz equation with nonpositive anisotropy constants in three or four dimension space. The partial regularity is proved up to the boundary and this result is an important supplement to those for the Dirichlet problem or the homogeneous Neumann problem.展开更多
The existence of solutions for one dimensional p-Laplace equation (φp(u′))′=f(t,u,u′) with t∈(0,1) and Фp(s)=|s|^p-2 s, s≠0 subjected to Neumann boundary value problem at u′(0) = 0, u′(1) = 0....The existence of solutions for one dimensional p-Laplace equation (φp(u′))′=f(t,u,u′) with t∈(0,1) and Фp(s)=|s|^p-2 s, s≠0 subjected to Neumann boundary value problem at u′(0) = 0, u′(1) = 0. By using the degree theory, the sufficient conditions of the existence of solutions for p-Laplace equation subjected to Neumann boundary value condition are established.展开更多
Solving optimization problems with partial differential equations constraints is one of the most challenging problems in the context of industrial applications. In this paper, we study the finite volume element method...Solving optimization problems with partial differential equations constraints is one of the most challenging problems in the context of industrial applications. In this paper, we study the finite volume element method for solving the elliptic Neumann boundary control problems. The variational discretization approach is used to deal with the control. Numerical results demonstrate that the proposed method for control is second-order accuracy in the <em>L</em><sup>2</sup> (Γ) and <em>L</em><sup>∞</sup> (Γ) norm. For state and adjoint state, optimal convergence order in the <em>L</em><sup>2</sup> (Ω) and <em>H</em><sup>1</sup> (Ω) can also be obtained.展开更多
We analyze the discretization of a Neumann boundary control problem with a stochastic parabolic equation, where additive noise occurs in the Neumann boundary condition. The convergence is established for general filtr...We analyze the discretization of a Neumann boundary control problem with a stochastic parabolic equation, where additive noise occurs in the Neumann boundary condition. The convergence is established for general filtration, and the convergence rate O(τ1/4-?+ h1/2-?) is derived for the natural filtration of the Q-Wiener process.展开更多
We consider a class of free boundary problems with Neumann boundary conditions.We would like to give certain results with regularity of solutions(mainly the local interior and boundary Lipschitz continuity).We will al...We consider a class of free boundary problems with Neumann boundary conditions.We would like to give certain results with regularity of solutions(mainly the local interior and boundary Lipschitz continuity).We will also show an explicit form of solution under well-specified conditions.展开更多
This paper deals with the blow-up properties of solutions to a system of heat equations u_t=Δ_u,v_t=Δv in B_R×(0,T) with the Neumann boundary conditions u/η=e^v,v/η=e^u on S_R×[0,T).The exact blow-up rat...This paper deals with the blow-up properties of solutions to a system of heat equations u_t=Δ_u,v_t=Δv in B_R×(0,T) with the Neumann boundary conditions u/η=e^v,v/η=e^u on S_R×[0,T).The exact blow-up rates are established.It is also proved that the blow-up will occur only on the boundary.展开更多
In this paper, for a coupled system of wave equations with iNeumann boundary controls, the exact boundary synchronization is taken into consideration. Results are then extended to the case of synchronization by groups...In this paper, for a coupled system of wave equations with iNeumann boundary controls, the exact boundary synchronization is taken into consideration. Results are then extended to the case of synchronization by groups. Moreover, the determination of the state of synchronization by groups is discussed with details for the synchronization and for the synchronization by 3-groups, respectively.展开更多
In this paper we consider the finite time quenching behavior of solutions to a semilinear heat equation with a nonlinear Neumann boundary condition. Firstly, we establish conditions on nonlinear source and boundary to...In this paper we consider the finite time quenching behavior of solutions to a semilinear heat equation with a nonlinear Neumann boundary condition. Firstly, we establish conditions on nonlinear source and boundary to guarantee that the solution doesn't quench for all time. Secondly, we give sufficient conditions on data such that the solution quenches in finite time, and derive an upper bound of quenching time. Thirdly, undermore restrictive conditions, we obtain a lower bound of quenching time. Finally, we give the exact bounds of quenching time of a special example.展开更多
In this paper, we obtain the existence of positive solutions for singular second-order Neumann boundary value problem by using the fixed point indices, the result generalizes some present results.
In this paper, we study a class of fourth-order Neumann boundary value problem (NBVP for short). By virtue of fixed point index and the spectral theory of linear operators, the existence of positive solutions is obtai...In this paper, we study a class of fourth-order Neumann boundary value problem (NBVP for short). By virtue of fixed point index and the spectral theory of linear operators, the existence of positive solutions is obtained under the assumption that the nonlinearity satisfies sublinear or superlinear conditions, which are relevant to the first eigenvalue of the corresponding linear operator.展开更多
The author of this paper, by means of the semi-rank theory, establish a new comparative theorem and give the existence of maximal and minimal solutions to Neumann boundary value problems of second order nonlinear diff...The author of this paper, by means of the semi-rank theory, establish a new comparative theorem and give the existence of maximal and minimal solutions to Neumann boundary value problems of second order nonlinear differential equation in ordered Banach spaces when the upper and lower solutions in the reversed order of the problem are given.展开更多
In this paper, we investigate the Cahn-Hilliard equation defined on the half space and subject to the Neumann boundary and initial condition. For given initial data in some sobolev space, we prove the existence and an...In this paper, we investigate the Cahn-Hilliard equation defined on the half space and subject to the Neumann boundary and initial condition. For given initial data in some sobolev space, we prove the existence and analytic smoothing effect of the solution.展开更多
In this paper,we establish the lower bounds estimate of the blow up time for solutions to the nonlocal cross-coupled porous medium equations with nonlocal source terms under Dirichlet and Neumann boundary conditions.T...In this paper,we establish the lower bounds estimate of the blow up time for solutions to the nonlocal cross-coupled porous medium equations with nonlocal source terms under Dirichlet and Neumann boundary conditions.The results are obtained by using some differential inequality technique.展开更多
In this paper,we study a lattice Boltzmann method for the advectiondiffusion equation with Neumann boundary conditions on general boundaries.A novel mass conservative scheme is introduced for implementing such boundar...In this paper,we study a lattice Boltzmann method for the advectiondiffusion equation with Neumann boundary conditions on general boundaries.A novel mass conservative scheme is introduced for implementing such boundary conditions,and is analyzed both theoretically and numerically.Second order convergence is predicted by the theoretical analysis,and numerical investigations show that the convergence is at or close to the predicted rate.The numerical investigations include time-dependent problems and a steady-state diffusion problem for computation of effective diffusion coefficients.展开更多
文摘We consider a strongly non-linear degenerate parabolic-hyperbolic problem with p(x)-Laplacian diffusion flux function. We propose an entropy formulation and prove the existence of an entropy solution.
文摘We provide a kernel-regularized method to give theory solutions for Neumann boundary value problem on the unit ball. We define the reproducing kernel Hilbert space with the spherical harmonics associated with an inner product defined on both the unit ball and the unit sphere, construct the kernel-regularized learning algorithm from the view of semi-supervised learning and bound the upper bounds for the learning rates. The theory analysis shows that the learning algorithm has better uniform convergence according to the number of samples. The research can be regarded as an application of kernel-regularized semi-supervised learning.
基金partially supported by National Natural Science Foundation of China(11771380)Natural Science Foundation of Jiangsu Province(BK20191436).
文摘In this paper,a fractional Laplacian mutualistic system under Neumann boundary conditions is studied.Using the method of upper and lower solutions,it is proven that the solutions of the fractional Laplacian strong mutualistic model with Neumann boundary conditions will blow up when the intrinsic growth rates of species are large.
文摘This paper deals with the blow-up properties of solutions to semilinear heat equation ut-uxx= up in (0, 1) × (0, T) with the Neumann boundary condition ux(0, t) = 0, u:x1, t) = 1 on [0, T). The necessary and sufficient conditions under which all solutions to have a finite time blow-up and the exact blow-up rates are established. It is proved that the blow-up will occur only at the boundary x = 1. The asymptotic behavior near the blow-up time is also studied.
文摘An iterative direct-forcing immersed boundary method is extended and used to solve convection heat transfer problems.The pressure,momentum source,and heat source at immersed boundary points are calculated simultaneously to achieve the best coupling.Solutions of convection heat transfer problems with both Dirichlet and Neumann boundary conditions are presented.Two approaches for the implementation of Neumann boundary condition,i.e.direct and indirect methods,are introduced and compared in terms of accuracy and computational efficiency.Validation test cases include forced convection on a heated cylinder in an unbounded flow field and mixed convection around a circular body in a lid-driven cavity.Furthermore,the proposed method is applied to study the mixed convection around a heated rotating cylinder in a square enclosure with both iso-heat flux and iso-thermal boundary conditions.Computational results show that the order of accuracy of the indirect method is less than the direct method.However,the indirect method takes less computational time both in terms of the implementation of the boundary condition and the post processing time required to compute the heat transfer variables such as the Nusselt number.It is concluded that the iterative direct-forcing immersed boundary method is a powerful technique for the solution of convection heat transfer problems with stationary/moving boundaries and various boundary conditions.
文摘In this work we show that homogeneous Neumann boundary conditions inhibit the Coleman-Weinberg mechanism for spontaneous symmetry breaking in the scalar electrodynamics if the length of the finite region is small enough (a = e2Mφ-1, where M, is the mass of the scalar field generated by the Coleman-Weinberg mechanism).
基金Supported by the Science Foundation of Zhejiang Sci-Tech University(No.0905828-Y)
文摘We establish an extension result of existence and partial regularity for the nonzero Neumann initial-boundary value problem of the Landau-Lifshitz equation with nonpositive anisotropy constants in three or four dimension space. The partial regularity is proved up to the boundary and this result is an important supplement to those for the Dirichlet problem or the homogeneous Neumann problem.
文摘The existence of solutions for one dimensional p-Laplace equation (φp(u′))′=f(t,u,u′) with t∈(0,1) and Фp(s)=|s|^p-2 s, s≠0 subjected to Neumann boundary value problem at u′(0) = 0, u′(1) = 0. By using the degree theory, the sufficient conditions of the existence of solutions for p-Laplace equation subjected to Neumann boundary value condition are established.
文摘Solving optimization problems with partial differential equations constraints is one of the most challenging problems in the context of industrial applications. In this paper, we study the finite volume element method for solving the elliptic Neumann boundary control problems. The variational discretization approach is used to deal with the control. Numerical results demonstrate that the proposed method for control is second-order accuracy in the <em>L</em><sup>2</sup> (Γ) and <em>L</em><sup>∞</sup> (Γ) norm. For state and adjoint state, optimal convergence order in the <em>L</em><sup>2</sup> (Ω) and <em>H</em><sup>1</sup> (Ω) can also be obtained.
基金supported by National Natural Science Foundation of China (Grant No.11901410)the Fundamental Research Funds for the Central Universities in China (Grant No. 2020SCU12063)。
文摘We analyze the discretization of a Neumann boundary control problem with a stochastic parabolic equation, where additive noise occurs in the Neumann boundary condition. The convergence is established for general filtration, and the convergence rate O(τ1/4-?+ h1/2-?) is derived for the natural filtration of the Q-Wiener process.
文摘We consider a class of free boundary problems with Neumann boundary conditions.We would like to give certain results with regularity of solutions(mainly the local interior and boundary Lipschitz continuity).We will also show an explicit form of solution under well-specified conditions.
基金This work is supported by the National Natural Science Foundation of China
文摘This paper deals with the blow-up properties of solutions to a system of heat equations u_t=Δ_u,v_t=Δv in B_R×(0,T) with the Neumann boundary conditions u/η=e^v,v/η=e^u on S_R×[0,T).The exact blow-up rates are established.It is also proved that the blow-up will occur only on the boundary.
基金supported by the National Natural Science Foundation of China(No.11121101)the National Basic Research Program of China(No.2013CB834100)
文摘In this paper, for a coupled system of wave equations with iNeumann boundary controls, the exact boundary synchronization is taken into consideration. Results are then extended to the case of synchronization by groups. Moreover, the determination of the state of synchronization by groups is discussed with details for the synchronization and for the synchronization by 3-groups, respectively.
文摘In this paper we consider the finite time quenching behavior of solutions to a semilinear heat equation with a nonlinear Neumann boundary condition. Firstly, we establish conditions on nonlinear source and boundary to guarantee that the solution doesn't quench for all time. Secondly, we give sufficient conditions on data such that the solution quenches in finite time, and derive an upper bound of quenching time. Thirdly, undermore restrictive conditions, we obtain a lower bound of quenching time. Finally, we give the exact bounds of quenching time of a special example.
文摘In this paper, we obtain the existence of positive solutions for singular second-order Neumann boundary value problem by using the fixed point indices, the result generalizes some present results.
基金Supported by NNSF of China (No.60665001) Educational Department of Jiangxi Province(No.GJJ08358+1 种基金 No.GJJ08359 No.JXJG07436)
文摘In this paper, we study a class of fourth-order Neumann boundary value problem (NBVP for short). By virtue of fixed point index and the spectral theory of linear operators, the existence of positive solutions is obtained under the assumption that the nonlinearity satisfies sublinear or superlinear conditions, which are relevant to the first eigenvalue of the corresponding linear operator.
文摘The author of this paper, by means of the semi-rank theory, establish a new comparative theorem and give the existence of maximal and minimal solutions to Neumann boundary value problems of second order nonlinear differential equation in ordered Banach spaces when the upper and lower solutions in the reversed order of the problem are given.
文摘In this paper, we investigate the Cahn-Hilliard equation defined on the half space and subject to the Neumann boundary and initial condition. For given initial data in some sobolev space, we prove the existence and analytic smoothing effect of the solution.
基金supported by Natural Science Basic Research Project of Shaanxi Province(2019JM-534)Soft Science Project of Shaanxi Province(2019KRM169)+2 种基金Planned Projects of the 13th Five-year Plan for Education Science of Shaanxi Province(SGH18H544)Project on Higher Education Teaching Reform of Xi'an International University(2019B36)the Youth Innovation Team of Shaanxi Universities.
文摘In this paper,we establish the lower bounds estimate of the blow up time for solutions to the nonlocal cross-coupled porous medium equations with nonlocal source terms under Dirichlet and Neumann boundary conditions.The results are obtained by using some differential inequality technique.
基金financed by the VINN Excellence center SuMo Biomaterials,supported by Vinnova.
文摘In this paper,we study a lattice Boltzmann method for the advectiondiffusion equation with Neumann boundary conditions on general boundaries.A novel mass conservative scheme is introduced for implementing such boundary conditions,and is analyzed both theoretically and numerically.Second order convergence is predicted by the theoretical analysis,and numerical investigations show that the convergence is at or close to the predicted rate.The numerical investigations include time-dependent problems and a steady-state diffusion problem for computation of effective diffusion coefficients.