Several new sufficient conditions are given for the global attractivity of solutions of a kind of delay difference equations. They either include or improve some known results and put the study of Ladas' conjectur...Several new sufficient conditions are given for the global attractivity of solutions of a kind of delay difference equations. They either include or improve some known results and put the study of Ladas' conjecture forward.展开更多
Aim To obtain new criteria for asymptotic behavior and nonexistence of positive solutions of nonlinear neutral delay difference equations. Methods By means of Hlder inequality and a method of direct analysis, some i...Aim To obtain new criteria for asymptotic behavior and nonexistence of positive solutions of nonlinear neutral delay difference equations. Methods By means of Hlder inequality and a method of direct analysis, some interesting Lemmas were offered. Results and Conclusion New criteria for asymptotic behavior and nonexistence of positive solutions of nonlinear neutral delay difference equations are established, which extend and improve the results obtained in the literature. Some interesting examples illustrating the importance of our results are also included.展开更多
In this paper,a sufficient condition for the global asymptotic stability of the solutions of the following nonlinear delay difference equation is obtained, xn+ 1=xn+xn- 1xn- 2 +a xnxn- 1+xn- 2 +a, n =0 ,1 ,..., ...In this paper,a sufficient condition for the global asymptotic stability of the solutions of the following nonlinear delay difference equation is obtained, xn+ 1=xn+xn- 1xn- 2 +a xnxn- 1+xn- 2 +a, n =0 ,1 ,..., where a∈ [0 ,∞ ) and the initial values x- 2 ,x- 1,x0 ∈ (0 ,∞ ) .As a special case,a conjecture by Ladas is confirmed.展开更多
The global attractivity of the delay difference equation Deltax(n) + a(n)x(n) + f(n, Sigma(s = -k)(0)(q) over bar (s), (n) x(s + n)) = 0, which includes the discrete type of many mathematical ecological equations, was...The global attractivity of the delay difference equation Deltax(n) + a(n)x(n) + f(n, Sigma(s = -k)(0)(q) over bar (s), (n) x(s + n)) = 0, which includes the discrete type of many mathematical ecological equations, was discussed. The sufficient conditions that guarantee every solution to converge to zero are obtained. Many known results are improved and generated.展开更多
In this paper we study the Oscillatory behaviour of the second order delay differenceequation.（1）△（r<sub>n</sub>△A<sub>n</sub>）+P<sub>n</sub>A<sub>n-k</sub>=0,n=n&...In this paper we study the Oscillatory behaviour of the second order delay differenceequation.（1）△（r<sub>n</sub>△A<sub>n</sub>）+P<sub>n</sub>A<sub>n-k</sub>=0,n=n<sub>0</sub>,n<sub>0</sub>+1……where{P<sub>n</sub>}（?）is a nonnegative Sequenceof real number,（?）is a positive sequence of real number with sum from n=n<sub>0</sub> to +∞（1/r<sub>n</sub>）=+∞,K is a positive integer and △A<sub>n</sub>=A<sub>n+1</sub>-A<sub>n</sub> we prove that each one of following conditions.imples that al solutions of Eq（1）oscillate,where R<sub>n</sub>=sum from i=n<sub>0</sub> to n（1/r<sub>i</sub>展开更多
China＇s first interest rate hike during the last decade, aiming to cool down the seemingly overheated real estate market, had aroused more caution on housing market. This paper aims to analyze the housing price dynam...China＇s first interest rate hike during the last decade, aiming to cool down the seemingly overheated real estate market, had aroused more caution on housing market. This paper aims to analyze the housing price dynamics after an unanticipated economic shock, which was believed to have similar properties with the backward-looking expecta- tion models. The analysis of the housing price dynamics is based on the cobweb model with a simple user cost affected demand and a stock-flow supply assumption. Several nth- order delay rational difference equations are set up to illustrate the properties of housing dynamics phenomena, such as the equilibrium or oscillations, overshoot or undershoot and convergent or divergent, for a kind of heterogeneous backward-looking expectation models. The results show that demand elasticity is less than supply elasticity is not a necessary condition for the occurrence of oscillation. The housing price dynamics will vary substantially with the heterogeneous backward-looking expectation assumption and some other endogenous factors.展开更多
A new sufficient condition is given for the global attractivity of solutions ofthe delay difference equation xn+1= xnf(xn, zn-1), n = 0,1…,As an application, ourresults partly confirm a conjecture of G. Ladas.
Consider the neutral delay difference equation △[p(t)x(t)-q(t)x(t-τ)] + r(t)x(t-δ(t)) =0 (*)where t ∈{a, a + 1, a + 2,…} and p(t) > 0, q(t) ≥ 0, r(t) ≥ 0, δ(t) ∈ {0, 1, 2,…} with,lim(t-δ(t)) =∞ and τ∈...Consider the neutral delay difference equation △[p(t)x(t)-q(t)x(t-τ)] + r(t)x(t-δ(t)) =0 (*)where t ∈{a, a + 1, a + 2,…} and p(t) > 0, q(t) ≥ 0, r(t) ≥ 0, δ(t) ∈ {0, 1, 2,…} with,lim(t-δ(t)) =∞ and τ∈ { 1, 2, 3,…}. Note that the delay of the difference equation may vary, thus the equation may not be of constant order. We obtain some sufficient conditions for the oscillation of Equation (*) and the second order self-adjoint difference equation △[p(t-1)△y(t-1)]+r(t)y(t) = 0.And the work in Timothy Peil [5] is improved.AMS (1991) No. 39A10, 39A12展开更多
Consider the nonlinear delay difference equation x<sub>n+1</sub>-x<sub>n</sub>+sum j=1 to m p<sub>j</sub>f<sub>j</sub>（x<sub>n</sub>-k<sub>j</sub&...Consider the nonlinear delay difference equation x<sub>n+1</sub>-x<sub>n</sub>+sum j=1 to m p<sub>j</sub>f<sub>j</sub>（x<sub>n</sub>-k<sub>j</sub>）=0. We establish a linearized oscillation result of this equation,which is the extension of the result in the paper [1].展开更多
Some sufficient, conditions for boundedness and persistence and global asymptotic stability of solutions for a class of delay difference equations with higher order are obtained, which partly solve G. Ladas' two o...Some sufficient, conditions for boundedness and persistence and global asymptotic stability of solutions for a class of delay difference equations with higher order are obtained, which partly solve G. Ladas' two open problems and extend some known results.展开更多
This paper studies the global attractivity of the positive equilibrium 1 of the delay logistic difference equation Δ y n=p ny n(1-y τ(n) ), n=0,1,2,...,(*)where {p n} is a sequence of positive real n...This paper studies the global attractivity of the positive equilibrium 1 of the delay logistic difference equation Δ y n=p ny n(1-y τ(n) ), n=0,1,2,...,(*)where {p n} is a sequence of positive real numbers, {τ(n)} is a nondecreasing sequence of integers, τ(n)<n and lim n→∞τ(n)=∞ .It is proved that ifnj=τ(n)p j≤54 for sufficiently large n and ∞j=0p j=∞,then all positive solutions of Eq.(*) tend to 1 as n→∞ .The results improve the existing results in literature.展开更多
The author studied the existence of positive solutions of the delay logistic difference equation Δ y n=p ny n(1-y τ(n) ), n =0,1,2,.... where { p n } is a sequence of positive real numbers, { τ(n) } is a nondecreas...The author studied the existence of positive solutions of the delay logistic difference equation Δ y n=p ny n(1-y τ(n) ), n =0,1,2,.... where { p n } is a sequence of positive real numbers, { τ(n) } is a nondecreasing sequence of integers, τ(n)<n and lim n →∞ τ(n) =∞. A sufficient condition for the existence of positive solutions of the equation was given.展开更多
In this paper, we study oscillation of solutions for a class of high order neutral delay difference equations with variable coefficients -τm [x（t） - c（t）x（t - τ）] = （-1）mp（t）x（t - σ）, t ≥ t0 〉 0. Some...In this paper, we study oscillation of solutions for a class of high order neutral delay difference equations with variable coefficients -τm [x（t） - c（t）x（t - τ）] = （-1）mp（t）x（t - σ）, t ≥ t0 〉 0. Some sufficient conditions are obtained for bounded oscillation of the solutions.展开更多
For the infinite delay difference equations of the general form, two new uniform asymptotic stability criteria are established in terms of the discrete Liapunov functionals.
Based on the Leggett-Williams fixed point theorem for a Banach space, we establish the existence of three positive periodic solutions for a class of delay difference equations.
This paper deals with the oscillatory properties of a class of nonlinear difference equations with several delays. Sufficient criteria in the form of infinite sum for the equations to be oscillatory are obtained.
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.
In this paper, we establish necessary and sufficient conditions for the zero solution to a class of higher order delay linear difference equations to be asymptotically stable, which are easy to be verified and to be a...In this paper, we establish necessary and sufficient conditions for the zero solution to a class of higher order delay linear difference equations to be asymptotically stable, which are easy to be verified and to be applied.展开更多
In this paper, we first consider a delay difference equation of neutral type of the form: Δ(y_n+py_(n-k))+q_ny_(n-)=0 for n∈Z^+(0) (1*) and give a different condition from that of Yu and Wang (Funkcial Ekvac, 1994,...In this paper, we first consider a delay difference equation of neutral type of the form: Δ(y_n+py_(n-k))+q_ny_(n-)=0 for n∈Z^+(0) (1*) and give a different condition from that of Yu and Wang (Funkcial Ekvac, 1994, 37(2): 241 248) to guarantee that every non-oscillatory solution of (1~*) with p=1 tends to zero as n→∞ Moreover, we consider a delay reaction-diffusion difference equation of neutral type of the form: Δ_1(u_(n,m)+pu_(n-k,m)+q_(n,m)u_(n-m)=a^2Δ_2~2u_(n+1,m-1) for (n,m)∈Z^+(0)×Ω. (2*) study various casks of p in the neutral term and obtain that if p≥-1 then every non-oscillatory solution of (2~*) tends uniformly in m∈Ω to zero as n→∞: if p=-1 then every solution of (2~*) oscillates and if p<-1 then every non-oscillatory solution of (2~*) goes uniformly in m∈Ω to infinity or minus infinity as n→∞ under some hypotheses.展开更多
文摘Several new sufficient conditions are given for the global attractivity of solutions of a kind of delay difference equations. They either include or improve some known results and put the study of Ladas' conjecture forward.
文摘Aim To obtain new criteria for asymptotic behavior and nonexistence of positive solutions of nonlinear neutral delay difference equations. Methods By means of Hlder inequality and a method of direct analysis, some interesting Lemmas were offered. Results and Conclusion New criteria for asymptotic behavior and nonexistence of positive solutions of nonlinear neutral delay difference equations are established, which extend and improve the results obtained in the literature. Some interesting examples illustrating the importance of our results are also included.
基金Supported by the National Natural Science Foundation of China(1 0 0 71 0 2 2 ) Mathematical TianyuanFoundation of China(TY1 0 0 2 6 0 0 2 - 0 1 - 0 5 - 0 3 ) Shanghai Priority Academic Discipline Foundation
文摘In this paper,a sufficient condition for the global asymptotic stability of the solutions of the following nonlinear delay difference equation is obtained, xn+ 1=xn+xn- 1xn- 2 +a xnxn- 1+xn- 2 +a, n =0 ,1 ,..., where a∈ [0 ,∞ ) and the initial values x- 2 ,x- 1,x0 ∈ (0 ,∞ ) .As a special case,a conjecture by Ladas is confirmed.
文摘The global attractivity of the delay difference equation Deltax(n) + a(n)x(n) + f(n, Sigma(s = -k)(0)(q) over bar (s), (n) x(s + n)) = 0, which includes the discrete type of many mathematical ecological equations, was discussed. The sufficient conditions that guarantee every solution to converge to zero are obtained. Many known results are improved and generated.
文摘In this paper we study the Oscillatory behaviour of the second order delay differenceequation.（1）△（r<sub>n</sub>△A<sub>n</sub>）+P<sub>n</sub>A<sub>n-k</sub>=0,n=n<sub>0</sub>,n<sub>0</sub>+1……where{P<sub>n</sub>}（?）is a nonnegative Sequenceof real number,（?）is a positive sequence of real number with sum from n=n<sub>0</sub> to +∞（1/r<sub>n</sub>）=+∞,K is a positive integer and △A<sub>n</sub>=A<sub>n+1</sub>-A<sub>n</sub> we prove that each one of following conditions.imples that al solutions of Eq（1）oscillate,where R<sub>n</sub>=sum from i=n<sub>0</sub> to n（1/r<sub>i</sub>
文摘China＇s first interest rate hike during the last decade, aiming to cool down the seemingly overheated real estate market, had aroused more caution on housing market. This paper aims to analyze the housing price dynamics after an unanticipated economic shock, which was believed to have similar properties with the backward-looking expecta- tion models. The analysis of the housing price dynamics is based on the cobweb model with a simple user cost affected demand and a stock-flow supply assumption. Several nth- order delay rational difference equations are set up to illustrate the properties of housing dynamics phenomena, such as the equilibrium or oscillations, overshoot or undershoot and convergent or divergent, for a kind of heterogeneous backward-looking expectation models. The results show that demand elasticity is less than supply elasticity is not a necessary condition for the occurrence of oscillation. The housing price dynamics will vary substantially with the heterogeneous backward-looking expectation assumption and some other endogenous factors.
基金Supported by the NNSFC(10071022),Mathematical Tianyuan Foundation of China(Ty10026002-01-05-03)Shanghai Priority Academic Discipline.
文摘A new sufficient condition is given for the global attractivity of solutions ofthe delay difference equation xn+1= xnf(xn, zn-1), n = 0,1…,As an application, ourresults partly confirm a conjecture of G. Ladas.
文摘Consider the neutral delay difference equation △[p(t)x(t)-q(t)x(t-τ)] + r(t)x(t-δ(t)) =0 (*)where t ∈{a, a + 1, a + 2,…} and p(t) > 0, q(t) ≥ 0, r(t) ≥ 0, δ(t) ∈ {0, 1, 2,…} with,lim(t-δ(t)) =∞ and τ∈ { 1, 2, 3,…}. Note that the delay of the difference equation may vary, thus the equation may not be of constant order. We obtain some sufficient conditions for the oscillation of Equation (*) and the second order self-adjoint difference equation △[p(t-1)△y(t-1)]+r(t)y(t) = 0.And the work in Timothy Peil [5] is improved.AMS (1991) No. 39A10, 39A12
基金Supported by the National Natural Science Foundation of China
文摘Consider the nonlinear delay difference equation x<sub>n+1</sub>-x<sub>n</sub>+sum j=1 to m p<sub>j</sub>f<sub>j</sub>（x<sub>n</sub>-k<sub>j</sub>）=0. We establish a linearized oscillation result of this equation,which is the extension of the result in the paper [1].
文摘Some sufficient, conditions for boundedness and persistence and global asymptotic stability of solutions for a class of delay difference equations with higher order are obtained, which partly solve G. Ladas' two open problems and extend some known results.
文摘This paper studies the global attractivity of the positive equilibrium 1 of the delay logistic difference equation Δ y n=p ny n(1-y τ(n) ), n=0,1,2,...,(*)where {p n} is a sequence of positive real numbers, {τ(n)} is a nondecreasing sequence of integers, τ(n)<n and lim n→∞τ(n)=∞ .It is proved that ifnj=τ(n)p j≤54 for sufficiently large n and ∞j=0p j=∞,then all positive solutions of Eq.(*) tend to 1 as n→∞ .The results improve the existing results in literature.
文摘The author studied the existence of positive solutions of the delay logistic difference equation Δ y n=p ny n(1-y τ(n) ), n =0,1,2,.... where { p n } is a sequence of positive real numbers, { τ(n) } is a nondecreasing sequence of integers, τ(n)<n and lim n →∞ τ(n) =∞. A sufficient condition for the existence of positive solutions of the equation was given.
基金Supported by the National Natural Science Foundation of China (Grant No.10571050)the Science and Research Fund for Higher College of Hunan Province (Grant No.06C054)
文摘In this paper, we study oscillation of solutions for a class of high order neutral delay difference equations with variable coefficients -τm [x（t） - c（t）x（t - τ）] = （-1）mp（t）x（t - σ）, t ≥ t0 〉 0. Some sufficient conditions are obtained for bounded oscillation of the solutions.
基金Project supported by the National Natural Science Foundation of China (No. 19831030).
文摘For the infinite delay difference equations of the general form, two new uniform asymptotic stability criteria are established in terms of the discrete Liapunov functionals.
基金Project partially supported by Natural Science Foundation of Shanxi Province and Yanbei Normal University and by High Science and Technology Foundation of Shanxi Province and by Science and Technology Bureau of Datong City.
文摘Based on the Leggett-Williams fixed point theorem for a Banach space, we establish the existence of three positive periodic solutions for a class of delay difference equations.
基金This work is supported by the National Natural Science Foundation of China (No.40373003, 40372121) and CUGQNL0616, 0517.
文摘This paper deals with the oscillatory properties of a class of nonlinear difference equations with several delays. Sufficient criteria in the form of infinite sum for the equations to be oscillatory are obtained.
基金Supported by Natural Science Foundation of Heilongjiang Province under Grant No.A0207Foundation of Heilongjiang University for Youth Teacher under Grant No.QL200501
文摘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.
文摘In this paper, we establish necessary and sufficient conditions for the zero solution to a class of higher order delay linear difference equations to be asymptotically stable, which are easy to be verified and to be applied.
基金Research supported by Youth Science Foundation of Naval Aeronautical Engineering AcademyNational Natural Science Foundation of China (# 69974032).
文摘In this paper, we first consider a delay difference equation of neutral type of the form: Δ(y_n+py_(n-k))+q_ny_(n-)=0 for n∈Z^+(0) (1*) and give a different condition from that of Yu and Wang (Funkcial Ekvac, 1994, 37(2): 241 248) to guarantee that every non-oscillatory solution of (1~*) with p=1 tends to zero as n→∞ Moreover, we consider a delay reaction-diffusion difference equation of neutral type of the form: Δ_1(u_(n,m)+pu_(n-k,m)+q_(n,m)u_(n-m)=a^2Δ_2~2u_(n+1,m-1) for (n,m)∈Z^+(0)×Ω. (2*) study various casks of p in the neutral term and obtain that if p≥-1 then every non-oscillatory solution of (2~*) tends uniformly in m∈Ω to zero as n→∞: if p=-1 then every solution of (2~*) oscillates and if p<-1 then every non-oscillatory solution of (2~*) goes uniformly in m∈Ω to infinity or minus infinity as n→∞ under some hypotheses.
