Mathematical models of restoration and control of a single species with Allee effect

According to the initial density of a single species with Allee effect and corresponding management strategy, three kinds of mathematical models are presented to describe the evolutionary process of the species by impulsive differential equations. When the initial density of the species is larger than economic injury level (EIL) (or economical threshold, ET), impulsive harvest control is considered in a finite time to decrease the population of the species. The feasibility of the impulsive harvest control in a finite time is given by the existence of solution of the model with initial and boundary value problem. When the initial density of the species is less than EIL (or ET), the model with state feedback control is formulated according to the state of the species. The existence and stability of periodic solution of the model with state feedback control are discussed. When the initial density of the species is less than the Allee threshold and the species tends to extinction, the model with impulsive release at fixed moments is presented to study the restoration of the species. The conditions for the feasibility of periodic restoration of the species are given. Finally, some discussions are given.     

An application of variational method to second-order impulsive differential equation on the half-line

In this paper, we study the multiplicity of solutions for second-order impulsive differential equation with a parameter on the half-line. By using a variational method and a three critical points theorem, we give some new criteria to guarantee that the impulsive problem has at least three classical solutions. Also an example is given in this paper to illustrate the main results.     

Mixed Boundary Value Problems for a Class of Fractional Differential Equations with Impulses

We investigate a class of mixed boundary value problem of nonlinear impulsive fractional differential equations with a parameter. The uniqueness of this problem is proved by applying Banach fixed point theorem.     

A generalized Gronwall-Bellman-Ou-Iang type inequality for discontinuous functions and applications to BVP

In this paper we investigate a generalized Gronwall-Bellman-Ou-Iang type inequality for piecewise continuous functions. By studying the unknown function in different continuous regions Ω_kj of Ω, we give the complete estimate for the unknown function. We apply our result to a boundary value problem of a partial impulsive differential equation for estimation of its solution.     

Limit behaviour of optimal control problems governed by elliptic boundary value problems with equivalued surface

In this paper, we discuss the limit behaviour of optimal control problems governed by elliptic boundary value problems with equivalued surface when the equivalued surface boundary shrinks to a fixed point on the outer boundary of a bounded domain.     

On positive solutions of boundary value problems for second-order functional differential equations on infinite intervals

We study the existence of positive solutions for the following boundary value problem on infinite interval for second-order functional differential equations:

     

具有脉冲的分数阶Bagley-Torvik 模型边值问题

将具有脉冲的分数阶Bagley-Torvik微分方程边值问题巧妙地转化为积分方程,定义加权Banach空间及全连续算子,运用不动点定理获得该边值问题解的存在性定理.举例说明了定理的应用.最后提出有趣的研究问题.     

The equations of thermoelasticity with time-dependent coefficients

We consider an inhomogeneous thermoelastic system with second sound in one space dimension where the coefficients are space- and time-dependent. For Dirichlet-Neumann type boundary conditions the global existence of smooth solutions is proved by using the theory of Kato. Then the asymptotic behavior of the solutions is discussed.     

Optimal control of parameter distributed systems with impulses

This paper concerns optimal control problems with impulses. The optimal magnitude of impulses and the spatial position of impulses are studied. We obtain maximum principles for these problems.     

二阶时滞微分方程边值问题的正解

本文利用锥映射不动点指数定理研究了二阶时滞微分方程边值问题正解的存在性,其中τ>0.推广了Liu和Li关于常微分方程边值问题的工作.     

Existence and Uniqueness of Solutions for the Initial Value Problem of Fractional $q_{k}$-Difference Equations for Impulsive with Varying Orders

The paper studies the existence and uniqueness for impulsive fractional $q_{k}$-difference equations of initial value problems involving Riemann-Liouville fractional $q_{k}$-integral and $q_{k}$-derivative by defining a new $q$-shifting operator. In this paper, we obtain existence and uniqueness results for impulsive fractional $q_{k}$-difference equations of initial value problems by using the Schaefer''s fixed point theorem and Banach contraction mapping principle. In addition, the main result is illustrated with the aid of several examples.     

On a boundary value problem for delay differential equations of population dynamics and Chebyshev approximation

In this paper, a boundary value problem for delay differential equations of population dynamics is considered. We obtain approximate solutions by using Chebyshev polynomial series and Newton–Raphson's procedure and give the error estimation. The method of the error estimation has been obtained in an existence theorem proved by a part of the authors. We carry out some numerical experiments by a computer language MATLAB.     

A delayed epidemic model with stage-structure and pulses for pest management strategy

From a biological pest management standpoint, epidemic diseases models have become important tools in control of pest populations. This paper deals with an impulsive delay epidemic disease model with stage-structure and a general form of the incidence rate concerning pest control strategy, in which the pest population is subdivided into three subgroups: pest eggs, susceptible pests, infectious pests that do not attack crops. Using the discrete dynamical system determined by the stroboscopic map, we obtain the exact periodic susceptible pest-eradication solution of the system and observe that the susceptible pest-eradication periodic solution is globally attractive, provided that the amount of infective pests released periodically is larger than some critical value. When the amount of infective pests released is less than another critical value, the system is shown to be permanent, which implies that the trivial susceptible pest-eradication solution loses its attractivity. Our results indicate that besides the release amount of infective pests, the incidence rate, time delay and impulsive period can have great effects on the dynamics of our system.     

Solvability of fractional three-point boundary value problems with nonlinear growth

In this paper, we discuss the existence of solutions for a three-point boundary value problem of fractional differential equations with nonlinear growth. By using the coincidence degree theory, we present a existence result at resonance case.     

单调迭代法与一阶脉冲泛函微分方程周期边值问题

本文利用单调迭代法与上下解方法,研究了一阶脉冲泛函做分方程周期边值问题最大解与最小解的存在性.     

Impulsive periodic boundary value problems of first-order differential equations

In this paper, by using Schaeffer's theorem, we prove new existence theorems for a nonlinear periodic boundary value problem of first-order differential equations with impulses. Our results improve and generalize some known results.     

Numerical method for a singularly perturbed convection-diffusion problem with delay

This paper deals with the singularly perturbed boundary value problem for a linear second-order delay differential equation. For the numerical solution of this problem, we use an exponentially fitted difference scheme on a uniform mesh which is accomplished by the method of integral identities with the use of exponential basis functions and interpolating quadrature rules with weight and remainder term in integral form. It is shown that one gets first order convergence in the discrete maximum norm, independently of the perturbation parameter. Numerical results are presented which illustrate the theoretical results.     

A boundary value problem for Bitsadze equation in the unit disc

A boundary value problem for the Bitsadze equation

$\frac{{\partial ^2 }}{{\partial \bar z^2 }}u(x,y) \equiv \frac{1}{4}\left( {\frac{\partial }{{\partial x}} + i\frac{\partial }{{\partial y}}} \right)^2 u(x,y) = 0$

in the interior of the unit disc is considered. It is proved that the problem is Noetherian and its index is calculated, and solvability conditions for the non-homogeneous problem are proposed. Some solutions of the homogeneous problem are explicitely found.