Strict Stability of Impulsive Differential Equations

In this paper, we will extend the strict stability to impulsive differential equations. By using Lyapunov functions, we will get some criteria for the strict stability of impulsive differential equations, and we can see that impulses do contribute to the system＇s strict stability behavior. An example is also given in this paper to illustrate the efficiency of the obtained results.     

THE DYNAMICS FOR THE PRIME PRINCIPLECLASSICAL AND QUANTUM CHAOS

In this paper we study the dynamics for the prime principle. The p-nonlinear equations are derived from the prime principle. It defines the p-chaotic functions and studies the local solutions and global stability for the p-nonlinear equations. It suggests a new method for studying the nonlinear equations that studying the stability and instability of the p-nonlinear equations is transformed into studying the stability and instability for the nonliner terms of de~A/dt in the chaotic equations.     

STABILITY ANALYSIS OF LARGE-SCALE SYSTEMS WITH MULTIPLE DELAYS

This paper is concerned with the stability analysis of a class of linear timeinvariant large-scale systems with multiple delays. By using the properties of matrices, a sufficient condition of absolute stability is first derived for low order systems, described by differential-difference equations. Then a comparison theorem is presented for differential-difference inequalities. Finally, a sufficient condition of absolute stability for large-scale systems with multiple delays is established by using the aggregation technique based on vector Lyapunov functions. A numerical example is also given to illustrate the applicability of the stability criterion obtained in this paper.     

ON THE STABILITY OF THE RESIDUAL-FREE BUBBLES FOR THE NAVIER-STOKES EQUATIONS

This paper considers the Calerkin finite element method for the incompressible Navier-Stokes equations in two dimensions, where the finite-dimensional spaces employed consist of piecewise polynomials enriched with residual-free bubble （RFB） functions. The stability features of the residual-free bubble functions for the linearized Navier-Stokes equations are analyzed in this work. It is shown that the enrichment of the velocity space by bubble functions stabilizes the numerical method for any value of the viscosity parameter for triangular elements and for values of the viscosity parameter in the vanishing limit case for quadrilateral elements.     

THE STABILITY AND APPROXIMATION PROPERTIES OF RITZ-VOLTERRA PROJECTION AND APPLICATION,I

The purpose of this paper is to study the stability and approximation properties of Ritz-Volterra projection. Through constructing a new type of Green functions and making use of various properties and estimates related with the functions, we prove that the Ritz-Volterra projection defined on the finite-dimensional subspace S_h of H_o~1 possesses the W_p~1-stability and the optimal approxi mation properties in W_p~1 and L_p for 2≤p≤∞. Our results, in this paper, can be applied to the finite element approximations for many evolution equations such as parabolic and hyperbolic integrodifferential equations,Sobolevequations and visco-elasticity, etc.     

EQUIVALENCE OF SEMI-LAGRANGIAN AND LAGRANGE-GALERKIN SCHEMES UNDER CONSTANT ADVECTION SPEED

We compare in this paper two major implementations of large time-step schemes for advection equations, i.e., Semi-Lagrangian and Lagrange-Galerkin techniques. We show that SL schemes are equivalent to exact LG schemes via a suitable definition of the basis functions. In this paper, this equivalence will be proved assuming some simplifying hypoteses, mainly constant advection speed, uniform space grid, symmetry and translation invariance of the cardinal basis functions for interpolation. As a byproduct of this equivalence, we obtain a simpler proof of stability for SL schemes in the constant-coefficient case.     

Well-posedness and stability for an elliptic-parabolic free boundary problem modeling the growth of multi-layer tumors

In this paper we study a free boundary problem modeling the growth of multi-layer tumors. This free boundary problem contains one parabolic equation and one elliptic equation, defined on an unbounded domain in R2 of the form 0 〈 y 〈p（x,t）, where p（x,t） is an unknown function. Unlike previous works on this tumor model where unknown functions are assumed to be periodic and only elliptic equations are evolved in the model, in this paper we consider the case where unknown functions are not periodic functions and both elliptic and parabolic equations appear in the model. It turns out that this problem is more difficult to analyze rigorously. We first prove that this problem is locally well-posed in little H61der spaces. Next we investigate asymptotic behavior of the solution. By using the principle of linearized stability, we prove that if the surface tension coefficient y is larger than a threshold value y〉0, then the unique flat equilibrium is asymptotically stable provided that the constant c representing the ratio between the nutrient diffusion time and the tumor-cell doubling time is sufficiently small.     

φ0-STRICT STABILITY OF DELAY DIFFERENCE EQUATIONS WITH VARIATIONAL LYAPUNOV METHOD

In this paper, a new type of stability, namelyφ0-strict stability is extended for the delay difference equations, and by using variational cone-valued Lyapunov-like functions some sufficient conditions for such stability to hold are given.     

ON LIAPUNOV FUNCTIONAL IN THEORY OF STABILITY OF SYSTEMS WITH TIME-LAG

It is well known,that in the theory of stability in differential equations,Liapunov's second method may be the most important The center problem of Liapunov's second method is construction of Liapunov function for concrete problems.Beyond any doubt,construction of Liapunov functions is an art.In the case of functional differential equations,there were also many attempts to establish various kinds of Liapunov type theorems.Recently Burton[2]presented an excellent theorem using the Liapunov functional to solve the asymptotic stability of functional differential equation with bounded delay. However,the construction of such a Liapunov functional is still very hard for concrete problems. In this paper, by utilizing this theorem due to Burton,we construct concrete Liapunov functional for certain and nonlinear delay differential equations and derive new sufficient conditions for asymptotic stability.Those criteria improve the result of literature[1]and they are with simple forms,easily checked and applicable.     

Comparison principle and stability criteria for stochastic differential delay equations with Markovian switching

In the present paper we first obtain the comparison principle for the nonlinear stochastic differential delay equations with Markovian switching. Later, using this comparison principle, we obtain some stability criteria, including stability in probability, asymptotic stability in probability, stability in thepth mean, asymptotic stability in the pth mean and the pth moment exponential stability of such equations. Finally, an example is given to illustrate the effectiveness of our results.     

Weak exponential stability of stochastic differential equations

In this paper we introduce weak exponential stability of stochastic differential equations. In particular, we introduce weak exponential stability in mean, weak exponential asymptotical stability in mean and weak uniform asymptotical stability in mean. We also derive some results related to the above concepts     

On the Stability of Periodic Impulsive Systems

In this paper, we consider periodic systems of ordinary differential equations with impulse perturbations at fixed points of time. It is assumed that the system possesses the trivial solution. We show that if the trivial solution of the system is stable or asymptotically stable, then it is uniformly stable or uniformly asymptotically stable, respectively. By using the method of Lyapunov functions, we establish criteria of uniform asymptotical stability and instability.     

A new approach to practical stability of impulsive functional differential equations in terms of two measures

In this work, we consider a new approach to the practical stability theory of impulsive functional differential equations. With Lyapunov functionals and Razumikhin technique, we use a new technique in the division of Lyapunov functions, given by Shunian Zhang, and obtain conditions sufficient for the uniform practical (asymptotical) stability of impulsive delay differential equations. An example is also discussed to illustrate the advantage of the proposed results.     

Nonlinear stability of discontinuous Galerkin methods for delay differential equations

The present paper is devoted to a study of nonlinear stability of discontinuous Galerkin methods for delay differential equations. Some concepts, such as global and analogously asymptotical stability are introduced. We derive that discontinuous Galerkin methods lead to global and analogously asymptotical stability for delay differential equations. And these nonlinear stability properties reveal to the reader the relation between the perturbations of the numerical solution and that of the initial value or the systems.     

Stochastic asymptotical stability for stochastic impulsive differential equations and it is application to chaos synchronization

In this paper, the stochastic asymptotical stability of stochastic impulsive differential equations is studied, and a comparison theory about the stochastic asymptotical stability of trivial solution is established. From the comparison theory, we can find out whether the stochastic impulsive differential system is stochastic asymptotically stable by studying the stability of a deterministic comparison system. As an application of this theory, we study the problem of chaos synchronization in Chua circuit using impulsive method. Finally, numerical simulation is employed to verify the feasibility of our method.     

Stability of Liénard Equation

We consider a balance stability problem for the second order nonlinear differential equations of the Liénard type. Investigations are carried out by means of constant-sign Lyapunov functions for problems of stability, asymptotical stability (local and global), and instability. We implicitly formulate a method of construction of constant-sign functions suitable for solving problems of motion stability. Special attention is paid to a problem of non-asymptotical stability, where we demonstrate possibilities of new assertions that rely upon a usage of constant-sign Lyapunov functions.     

Global asymptotical stability of the positive equilibrium of a logistic competitive model

Global asymptotical stability of the positive equilibrium (PE) of a dynamical system is one of the research focus in theoretical studies of both continuous and discrete bio-mathematical models. In this paper, we shall establish the global asymptotical stability of the PE of a discrete Logistic competitive model in certain planar region. Indeed, sufficient conditions, dependent only on the parameters of the model, are obtained to ensure the global asymptotical stability of the PE in this region. The parameter region that corresponds to these sufficient conditions can be illustrated graphically and several examples of such regions are presented. Our approach to establish the global asymptotical stability of the PE involves proving the global attractivity of the PE in the planar region concerned and a key process here is the derivation of the maxima of the related functions in the planar region.     

ASYMPTOTIC STABILITY OF THIRD ORDER DELAY DIFFERENCE EQUATIONS WITH THREE PARAMETERS

In this paper, we obtain a necessary and sufficient condition for the asymptotical stability of the zero solution to the third order delay difference equations.     

DISSIPATIVITY BEHAVIOR OF IMPULSIVE FUNCTIONAL DIFFERENTIAL EQUATIONS

In this paper,we investigate the dissipativity behavior and give the range estimate for solutions of impulsive functional differential equations.Also,some criteria on asymptotical stability and exponential stability of the zero solution are obtained.     

Integro-sum inequalities and motion stability of systems with impulse perturbations

This article is devoted to the investigation of the properties of motion represented by essential nonlinear system of differential equations with impulse effect. The results, based on the solvability problem by S.A. Chaplygin for discontinuous functions, satisfy “integro-sum” inequalities. The conditions of boundedness, stability, asymptotical stability, practical stability, attraction motion for different kinds of nonlinearities of systems are obtained.