Neutral hyperbolic differential equations with continuous distributed devia-ting arguments are studied, and sufficient conditions for each solution of the boundary value problem to be oscillatory in a cylindrical doma...Neutral hyperbolic differential equations with continuous distributed devia-ting arguments are studied, and sufficient conditions for each solution of the boundary value problem to be oscillatory in a cylindrical domain are obtained.展开更多
The neuron model has been widely employed in neural-morphic computing systems and chaotic circuits.This study aims to develop a novel circuit simulation of a three-neuron Hopfield neural network(HNN)with coupled hyper...The neuron model has been widely employed in neural-morphic computing systems and chaotic circuits.This study aims to develop a novel circuit simulation of a three-neuron Hopfield neural network(HNN)with coupled hyperbolic memristors through the modification of a single coupling connection weight.The bistable mode of the hyperbolic memristive HNN(mHNN),characterized by the coexistence of asymmetric chaos and periodic attractors,is effectively demonstrated through the utilization of conventional nonlinear analysis techniques.These techniques include bifurcation diagrams,two-parameter maximum Lyapunov exponent plots,local attractor basins,and phase trajectory diagrams.Moreover,an encryption technique for color images is devised by leveraging the mHNN model and asymmetric structural attractors.This method demonstrates significant benefits in correlation,information entropy,and resistance to differential attacks,providing strong evidence for its effectiveness in encryption.Additionally,an improved modular circuit design method is employed to create the analog equivalent circuit of the memristive HNN.The correctness of the circuit design is confirmed through Multisim simulations,which align with numerical simulations conducted in Matlab.展开更多
Recently, Kreith, Kusano and Yoshida have studied the oscillation property of the hyperbolic equation u<sub>11</sub>-△u+c（t,x,u）=f（t,x）, （t,x）∈R<sub>+</sub>×Ωwith boundary conditi...Recently, Kreith, Kusano and Yoshida have studied the oscillation property of the hyperbolic equation u<sub>11</sub>-△u+c（t,x,u）=f（t,x）, （t,x）∈R<sub>+</sub>×Ωwith boundary condition （?）u/（?）n=g（t,x）, （t, x）∈R<sub>+</sub>×（?）Ω,and obtained some sufficient criterions for solution oscillation. In this note, we shall discuss the oscillation properties of solutions for a class of hyperbolic functional differential展开更多
With increasing engineering demands,there need high order accurate schemes embedded with precise physical information in order to capture delicate small scale structures and strong waves with correct“physics”.There ...With increasing engineering demands,there need high order accurate schemes embedded with precise physical information in order to capture delicate small scale structures and strong waves with correct“physics”.There are two families of high order methods:One is the method of line,relying on the Runge-Kutta(R-K)time-stepping.The building block is the Riemann solution labeled as the solution element“1”.Each step in R-K just has first order accuracy.In order to derive a fourth order accuracy scheme in time,one needs four stages labeled as“1111=4”.The other is the one-stage Lax-Wendroff(LW)type method,which is more compact but is complicated to design numerical fluxes and hard to use when applied to highly nonlinear problems.In recent years,the pair of solution element and dynamics element,labeled as“2”,are taken as the building block.The direct adoption of the dynamics implies the inherent temporal-spatial coupling.With this type of building blocks,a family of two-stage fourth order accurate schemes,labeled as“22=4”,are designed for the computation of compressible fluid flows.The resulting schemes are compact,robust and efficient.This paper contributes to elucidate how and why high order accurate schemes should be so designed.To some extent,the“22=4”algorithm extracts the advantages of the method of line and one-stage LW method.As a core part,the pair“2”is expounded and LW solver is revisited.The generalized Riemann problem(GRP)solver,as the discontinuous and nonlinear version of LW flow solver,and the gas kinetic scheme(GKS)solver,the microscopic LW solver,are all reviewed.The compact Hermite-type data reconstruction and high order approximation of boundary conditions are proposed.Besides,the computational performance and prospective discussions are presented.展开更多
We are concerned with global solutions of multidimensional(M-D)Riemann problems for nonlinear hyperbolic systems of conservation laws,focusing on their global configurations and structures.We present some recent devel...We are concerned with global solutions of multidimensional(M-D)Riemann problems for nonlinear hyperbolic systems of conservation laws,focusing on their global configurations and structures.We present some recent developments in the rigorous analysis of two-dimensional(2-D)Riemann problems involving transonic shock waves through several prototypes of hyperbolic systems of conservation laws and discuss some further M-D Riemann problems and related problems for nonlinear partial differential equations.In particular,we present four different 2-D Riemann problems through these prototypes of hyperbolic systems and show how these Riemann problems can be reformulated/solved as free boundary problems with transonic shock waves as free boundaries for the corresponding nonlinear conservation laws of mixed elliptic-hyperbolic type and related nonlinear partial differential equations.展开更多
We study central-upwind schemes for systems of hyperbolic conservation laws,recently introduced in[13].Similarly to staggered non-oscillatory central schemes,these schemes are central Godunov-type projection-evolution...We study central-upwind schemes for systems of hyperbolic conservation laws,recently introduced in[13].Similarly to staggered non-oscillatory central schemes,these schemes are central Godunov-type projection-evolution methods that enjoy the advantages of high resolution,simplicity,universality and robustness.At the same time,the central-upwind framework allows one to decrease a relatively large amount of numerical dissipation present at the staggered central schemes.In this paper,we present a modification of the one-dimensional fully-and semi-discrete central-upwind schemes,in which the numerical dissipation is reduced even further.The goal is achieved by a more accurate projection of the evolved quantities onto the original grid.In the semi-discrete case,the reduction of dissipation procedure leads to a new,less dissipative numerical flux.We also extend the new semi-discrete scheme to the twodimensional case via the rigorous,genuinely multidimensional derivation.The new semi-discrete schemes are tested on a number of numerical examples,where one can observe an improved resolution,especially of the contact waves.展开更多
In this paper, we prove that for every index perfect non-degenerate compact star-shaped hypersurface E C R2n, there exist at least n non-hyperbolic closed characteristics with even Maslov- type indices on E when n is ...In this paper, we prove that for every index perfect non-degenerate compact star-shaped hypersurface E C R2n, there exist at least n non-hyperbolic closed characteristics with even Maslov- type indices on E when n is even. When n is odd, there exist at least n closed characteristics with odd Maslov-type indices on E and at least （n - 1） of them are non-hyperbolic. Here we call a compact star-shaped hypersurfaee E ∈R2 index perfect if it carries only finitely many geometrically distinct prime closed characteristics, and every prime closed characteristic （T, y） on E possesses positive mean index and whose Maslov-type index i（y, m） of its m-th iterate satisfies i（y, m） ≠-1 when n is even, and i（y, rn） ≠2{-1,0} when n is odd for all rn E N.展开更多
This paper is concerned with the oscillations of neutral hyperbolic partial differential equations with delays. Necessary and sufficient, conditions are obtained for the oscillations of all solutions of the equations,...This paper is concerned with the oscillations of neutral hyperbolic partial differential equations with delays. Necessary and sufficient, conditions are obtained for the oscillations of all solutions of the equations, and these results are illustrated by some examples.展开更多
The energy eigenvalues of a Dirac particle for the hyperbolic-type potential field have been computed approximately. It is obtained a transcendental function of energy, F(E), by writing in terms of confluent Heun func...The energy eigenvalues of a Dirac particle for the hyperbolic-type potential field have been computed approximately. It is obtained a transcendental function of energy, F(E), by writing in terms of confluent Heun functions.The numerical values of energy are then obtained by fixing the zeros on "E-axis" for both complex functions Re[F(E)]and Im[F(E)].展开更多
In the present paper an existence and uniqueness of solution of the nonlo- cal boundary value problem for the third order loaded elliptic-hyperbolic type equa- tion in double-connected domain have been investigated. A...In the present paper an existence and uniqueness of solution of the nonlo- cal boundary value problem for the third order loaded elliptic-hyperbolic type equa- tion in double-connected domain have been investigated. At the proof of unequivocal solvability of the investigated problem, the extremum principle for the mixed type equations and method of integral equations have been used.展开更多
文摘Neutral hyperbolic differential equations with continuous distributed devia-ting arguments are studied, and sufficient conditions for each solution of the boundary value problem to be oscillatory in a cylindrical domain are obtained.
基金Project supported by the National Nature Science Foundation of China(Grant Nos.51737003 and 51977060)the Natural Science Foundation of Hebei Province(Grant No.E2011202051).
文摘The neuron model has been widely employed in neural-morphic computing systems and chaotic circuits.This study aims to develop a novel circuit simulation of a three-neuron Hopfield neural network(HNN)with coupled hyperbolic memristors through the modification of a single coupling connection weight.The bistable mode of the hyperbolic memristive HNN(mHNN),characterized by the coexistence of asymmetric chaos and periodic attractors,is effectively demonstrated through the utilization of conventional nonlinear analysis techniques.These techniques include bifurcation diagrams,two-parameter maximum Lyapunov exponent plots,local attractor basins,and phase trajectory diagrams.Moreover,an encryption technique for color images is devised by leveraging the mHNN model and asymmetric structural attractors.This method demonstrates significant benefits in correlation,information entropy,and resistance to differential attacks,providing strong evidence for its effectiveness in encryption.Additionally,an improved modular circuit design method is employed to create the analog equivalent circuit of the memristive HNN.The correctness of the circuit design is confirmed through Multisim simulations,which align with numerical simulations conducted in Matlab.
文摘Recently, Kreith, Kusano and Yoshida have studied the oscillation property of the hyperbolic equation u<sub>11</sub>-△u+c（t,x,u）=f（t,x）, （t,x）∈R<sub>+</sub>×Ωwith boundary condition （?）u/（?）n=g（t,x）, （t, x）∈R<sub>+</sub>×（?）Ω,and obtained some sufficient criterions for solution oscillation. In this note, we shall discuss the oscillation properties of solutions for a class of hyperbolic functional differential
基金This work is supported by NSFC(nos.11771054,91852207)and Foundation of LCP.
文摘With increasing engineering demands,there need high order accurate schemes embedded with precise physical information in order to capture delicate small scale structures and strong waves with correct“physics”.There are two families of high order methods:One is the method of line,relying on the Runge-Kutta(R-K)time-stepping.The building block is the Riemann solution labeled as the solution element“1”.Each step in R-K just has first order accuracy.In order to derive a fourth order accuracy scheme in time,one needs four stages labeled as“1111=4”.The other is the one-stage Lax-Wendroff(LW)type method,which is more compact but is complicated to design numerical fluxes and hard to use when applied to highly nonlinear problems.In recent years,the pair of solution element and dynamics element,labeled as“2”,are taken as the building block.The direct adoption of the dynamics implies the inherent temporal-spatial coupling.With this type of building blocks,a family of two-stage fourth order accurate schemes,labeled as“22=4”,are designed for the computation of compressible fluid flows.The resulting schemes are compact,robust and efficient.This paper contributes to elucidate how and why high order accurate schemes should be so designed.To some extent,the“22=4”algorithm extracts the advantages of the method of line and one-stage LW method.As a core part,the pair“2”is expounded and LW solver is revisited.The generalized Riemann problem(GRP)solver,as the discontinuous and nonlinear version of LW flow solver,and the gas kinetic scheme(GKS)solver,the microscopic LW solver,are all reviewed.The compact Hermite-type data reconstruction and high order approximation of boundary conditions are proposed.Besides,the computational performance and prospective discussions are presented.
基金The research of Gui-Qiang G.Chen was supported in part by the UK Engineering and Physical Sciences Research Council Awards EP/L015811/1,EP/V008854/1,EP/V051121/1the Royal Society-Wolfson Research Merit Award WM090014.
文摘We are concerned with global solutions of multidimensional(M-D)Riemann problems for nonlinear hyperbolic systems of conservation laws,focusing on their global configurations and structures.We present some recent developments in the rigorous analysis of two-dimensional(2-D)Riemann problems involving transonic shock waves through several prototypes of hyperbolic systems of conservation laws and discuss some further M-D Riemann problems and related problems for nonlinear partial differential equations.In particular,we present four different 2-D Riemann problems through these prototypes of hyperbolic systems and show how these Riemann problems can be reformulated/solved as free boundary problems with transonic shock waves as free boundaries for the corresponding nonlinear conservation laws of mixed elliptic-hyperbolic type and related nonlinear partial differential equations.
基金supported in part by the NSF Grant DMS-0310585The work of C.-T.Lin was supported in part by the NSC grants NSC 94-2115-M-126-003 and 91-2115-M-126-001.
文摘We study central-upwind schemes for systems of hyperbolic conservation laws,recently introduced in[13].Similarly to staggered non-oscillatory central schemes,these schemes are central Godunov-type projection-evolution methods that enjoy the advantages of high resolution,simplicity,universality and robustness.At the same time,the central-upwind framework allows one to decrease a relatively large amount of numerical dissipation present at the staggered central schemes.In this paper,we present a modification of the one-dimensional fully-and semi-discrete central-upwind schemes,in which the numerical dissipation is reduced even further.The goal is achieved by a more accurate projection of the evolved quantities onto the original grid.In the semi-discrete case,the reduction of dissipation procedure leads to a new,less dissipative numerical flux.We also extend the new semi-discrete scheme to the twodimensional case via the rigorous,genuinely multidimensional derivation.The new semi-discrete schemes are tested on a number of numerical examples,where one can observe an improved resolution,especially of the contact waves.
基金supported by NSFC(Grant Nos.11671215,11131004 and 11471169,11401555,11222105 and 11431001)LPMC of MOE of China+3 种基金Anhui Provincial Natural Science Foundation(Grant No.1608085QA01)MCME,LPMC of MOE of ChinaNankai UniversityBAICIT of Capital Normal University
文摘In this paper, we prove that for every index perfect non-degenerate compact star-shaped hypersurface E C R2n, there exist at least n non-hyperbolic closed characteristics with even Maslov- type indices on E when n is even. When n is odd, there exist at least n closed characteristics with odd Maslov-type indices on E and at least （n - 1） of them are non-hyperbolic. Here we call a compact star-shaped hypersurfaee E ∈R2 index perfect if it carries only finitely many geometrically distinct prime closed characteristics, and every prime closed characteristic （T, y） on E possesses positive mean index and whose Maslov-type index i（y, m） of its m-th iterate satisfies i（y, m） ≠-1 when n is even, and i（y, rn） ≠2{-1,0} when n is odd for all rn E N.
基金Supported by Natural Science Foundation of Hebei Province（102160） and Natural Science of Education office in Hebei Province （2004123）,
文摘This paper is concerned with the oscillations of neutral hyperbolic partial differential equations with delays. Necessary and sufficient, conditions are obtained for the oscillations of all solutions of the equations, and these results are illustrated by some examples.
基金partially supported by the Scientific and Technical Research Council of Turkey
文摘The energy eigenvalues of a Dirac particle for the hyperbolic-type potential field have been computed approximately. It is obtained a transcendental function of energy, F(E), by writing in terms of confluent Heun functions.The numerical values of energy are then obtained by fixing the zeros on "E-axis" for both complex functions Re[F(E)]and Im[F(E)].
文摘In the present paper an existence and uniqueness of solution of the nonlo- cal boundary value problem for the third order loaded elliptic-hyperbolic type equa- tion in double-connected domain have been investigated. At the proof of unequivocal solvability of the investigated problem, the extremum principle for the mixed type equations and method of integral equations have been used.
