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
This paper surveys some new results on the oscillation of all solutions of the linear nentral delaydifference equation of the form △(y<sub>n</sub> - p<sub>n</sub>y<sub>n-k</sub>) +...This paper surveys some new results on the oscillation of all solutions of the linear nentral delaydifference equation of the form △(y<sub>n</sub> - p<sub>n</sub>y<sub>n-k</sub>) + q<sub>n</sub>y<sub>n-l</sub> = 0, n = 0,1, 2…where { p<sub>n</sub> } and { q<sub>n</sub> } are twe real numbers sequences with q<sub>n</sub>≥0, and k and l are positive integers. These re-sults do not require the usual assumptionAlso, some interesting open problems on this topic am given.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
Consider the nonautonomous delay logistic equation △yn=pnyn（1-yn-ln/k）,n≥0, where {Pn}n≥0 is a sequence of nonnegative real numbers, {In}n≥0 is a sequence of positive integers satisfying n→∞lim（n-ln）=∞, and...Consider the nonautonomous delay logistic equation △yn=pnyn（1-yn-ln/k）,n≥0, where {Pn}n≥0 is a sequence of nonnegative real numbers, {In}n≥0 is a sequence of positive integers satisfying n→∞lim（n-ln）=∞, and k is a positive constant. Only solutions which are positive for n ≥ 0 are considered. We obtain a new sufficient for all positive solutions of （1） to oscillate about k which contains the corresponding result in [2] when i = 1.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
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
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
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 give necessary and sufficient conditions for oscillation of bounded solutions of nonlinear second order difference equation △(pn△yn)+ qnf(yn-rn) = 0. Obtained results improve theorems in the litera...In this paper, we give necessary and sufficient conditions for oscillation of bounded solutions of nonlinear second order difference equation △(pn△yn)+ qnf(yn-rn) = 0. Obtained results improve theorems in the literature [3,6,7].展开更多
By using the Riccati transformation and the Cauchy mean inequality, we shall derive some oscillatory criteria for the second order neutral delay difference equationΔ [a nΔ (x n+p nx g(n) )]+q nf(x σ(n) ...By using the Riccati transformation and the Cauchy mean inequality, we shall derive some oscillatory criteria for the second order neutral delay difference equationΔ [a nΔ (x n+p nx g(n) )]+q nf(x σ(n) )=0. These results generalize and improve some known results about both neutral and delay difference equations.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
Zhang and Yan in ref. [1] gave some sufficient conditions for the oscillation of eqs.(1) and (2) by using the methods as in difference equations with discrete arguments, and thereby revealed certain oscillation relati...Zhang and Yan in ref. [1] gave some sufficient conditions for the oscillation of eqs.(1) and (2) by using the methods as in difference equations with discrete arguments, and thereby revealed certain oscillation relation between difference equations with continuous arguments and discrete ones. However, the oscillation results in ref. [1] need the hypothesis liminf p_i(t)】0, which is an essential condition.t→∞ In this note, we compare eq. (1) with certain delay differential equation, and thereby establish some new sufficient conditions for the oscillation of eqs. (1) and (2). These conditions are integral conditions which do not need the hypothesis liminf p_i(t)】0.展开更多
In this paper, we present new oscillation criteria for certain class of second-order difference equation obtained by using a technique similar to the integral averaging technique. Our theorem complement some known osc...In this paper, we present new oscillation criteria for certain class of second-order difference equation obtained by using a technique similar to the integral averaging technique. Our theorem complement some known oscillation criteria.展开更多
The oscillation of a delay difference equationis studied and the necessary and sufficient condition for all positive solutions of (E) to oscillate about its positive equilibrium is obtained.
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>
基金Projects supported by the National Natural Science Foundation of China
文摘This paper surveys some new results on the oscillation of all solutions of the linear nentral delaydifference equation of the form △(y<sub>n</sub> - p<sub>n</sub>y<sub>n-k</sub>) + q<sub>n</sub>y<sub>n-l</sub> = 0, n = 0,1, 2…where { p<sub>n</sub> } and { q<sub>n</sub> } are twe real numbers sequences with q<sub>n</sub>≥0, and k and l are positive integers. These re-sults do not require the usual assumptionAlso, some interesting open problems on this topic am given.
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.
文摘Consider the nonautonomous delay logistic equation △yn=pnyn（1-yn-ln/k）,n≥0, where {Pn}n≥0 is a sequence of nonnegative real numbers, {In}n≥0 is a sequence of positive integers satisfying n→∞lim（n-ln）=∞, and k is a positive constant. Only solutions which are positive for n ≥ 0 are considered. We obtain a new sufficient for all positive solutions of （1） to oscillate about k which contains the corresponding result in [2] when i = 1.
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.
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 (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 the National Natural Science Foundation of China (19571023) the Natural Science Foundation of Hebei province (100139)
文摘In this paper, we give necessary and sufficient conditions for oscillation of bounded solutions of nonlinear second order difference equation △(pn△yn)+ qnf(yn-rn) = 0. Obtained results improve theorems in the literature [3,6,7].
文摘By using the Riccati transformation and the Cauchy mean inequality, we shall derive some oscillatory criteria for the second order neutral delay difference equationΔ [a nΔ (x n+p nx g(n) )]+q nf(x σ(n) )=0. These results generalize and improve some known results about both neutral and delay difference equations.
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Project supported by the National Natural Science Foundation of China.
文摘Zhang and Yan in ref. [1] gave some sufficient conditions for the oscillation of eqs.(1) and (2) by using the methods as in difference equations with discrete arguments, and thereby revealed certain oscillation relation between difference equations with continuous arguments and discrete ones. However, the oscillation results in ref. [1] need the hypothesis liminf p_i(t)】0, which is an essential condition.t→∞ In this note, we compare eq. (1) with certain delay differential equation, and thereby establish some new sufficient conditions for the oscillation of eqs. (1) and (2). These conditions are integral conditions which do not need the hypothesis liminf p_i(t)】0.
基金This research was supported by the NSF of China (19971053) and Shandong Province (Q97A05116).
文摘In this paper, we present new oscillation criteria for certain class of second-order difference equation obtained by using a technique similar to the integral averaging technique. Our theorem complement some known oscillation criteria.
基金This work is supported by National Natural Sciences Foundation of China.
文摘The oscillation of a delay difference equationis studied and the necessary and sufficient condition for all positive solutions of (E) to oscillate about its positive equilibrium is obtained.
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.
