一类基于尺度结构的种群系统的最优收获

分析一类食饵种群带有尺度结构的种群系统的最优收获问题.利用不动点定理证明了状态系统及其共轭系统非负解的存在唯一性,解对控制变量的连续依赖性.应用切锥法锥技巧导出了最优性条件,借助Ekeland变分原理讨论了最优收获策略的存在唯一性,推广了年龄结构种群模型中的相应结论.     

具有Size结构的捕食种群系统的最优收获策略

分析了一类捕食者种群带有Size结构的捕食-被捕食系统的最优收获问题. 利用不动点定理证明了状态系统及其共轭系统非负解的存在唯一性、解对控制变量的连续依赖性. 应用切锥法锥技巧导出了最优性条件, 借助Ekeland变分原理讨论了最优收获策略的存在唯一性, 推广了年龄结构种群模型中的相应结论.     

基于尺度结构的捕食-食饵种群系统的最优收获率北大核心CSCD

文章研究了基于尺度结构的捕食-食饵种群系统的最优收获率控制问题,通过控制种群的收获率使得种群分布达到理想状态并使收获成本最小.首先借助不动点定理证明了系统解的存在唯一性,其次导出共轭系统并利用切锥-法锥理论给出了收获控制为最优的必要性条件.     

基于尺度结构的捕食-食饵种群系统的最优收获率

文章研究了基于尺度结构的捕食-食饵种群系统的最优收获率控制问题,通过控制种群的收获率使得种群分布达到理想状态并使收获成本最小.首先借助不动点定理证明了系统解的存在唯一性,其次导出共轭系统并利用切锥-法锥理论给出了收获控制为最优的必要性条件.     

具扩散与年龄结构的三种群捕食与被捕食系统的最优收获

研究了一类具有空间扩散和年龄结构的三种群捕食与被捕食系统的最优收获问题,运用Banach不动点原理讨论了系统解的存在唯一性,证明了最优收获控制的存在性,给出了最大值原理.结果可为多种群扩散系统最优控制问题的实际研究提供理论基础.     

周期环境中捕食者具有尺度结构的三物种捕食-食饵系统的最优收获

对种群动力学及相关控制问题的研究,不仅具有理论意义,而且与生物多样性保护、病虫害防治及可再生资源的开发利用密切相关.该文研究了一类周期环境中具有两相互竞争食饵和一捕食者的三物种捕食 食饵系统的最优收获,其中捕食者具有尺度结构且用一阶偏微分方程描述.运用不动点定理证明了系统非负有界解的存在唯一性,并讨论了解关于控制变量的连续依赖性.应用切 法锥技巧导出最优收获条件,并借助Ekeland变分原理讨论了最优策略的存在唯一性.这里目标泛函表示收获三物种产生的净经济效益.所得结果将有利于可再生资源的开发.     

基于弹性增长的尺度结构种群的最优平衡收获

本文研究一类个体尺度具有弹性增长行为的种群模型的平衡态收获问题,种群加权总规模对个体生死率的影响各异.运用Ascoli-Arzela定理确立了最优解的存在性,借助针状变分法导出极值原理.最后通过对转换函数平衡态水平的细致分析,证明了最优策略的唯一性.     

一类基于时滞和年龄分布的种群控制问题

研究一类具有离散时滞和年龄结构的生物种群模型的最优收获策略,其状态方程由一阶偏泛函微分方程描述.运用极值化序列方法和Mazur定理证明了最优控制的存在性,借助非线性泛函分析中的切锥-法锥和共轭系统技巧导出了最优性条件.通过对共轭系统的细致分析,确立了最优控制的唯一性,给出了最优解的特征刻画.     

一类具有年龄结构的非线性种群扩散系统的最优收获控制

讨论了一类与年龄相关的非线性种群扩散系统的最优收获控制问题,证明了最优收获控制的存在性,并且给出了控制为最优的必要条件及其由偏微分方程组和变分不等式组成的最优性组.这些结果可为种群扩散系统最优控制问题的实际研究提供理论基础.     

具有年龄结构的竞争系统的最优输入率控制的存在性

本文研究了一类具有年龄结构的竞争种群系统的最优输入率控制的存在性问题.利用不动点定理,下半连续和Ekeland变分原理,得到了最优控制的存在唯一性.     

Nonlinear optimal control problems of degenerate parabolic equations with logistic time-varying delays of convolution type

In this article, we consider a bioeconomic model for optimal control problems which are governed by degenerate parabolic equations governing diffusive biological species with logistic growth terms and multiple time-varying delays. The time-varying delays are given in a convolution form. The existence, uniqueness and regularity results to the state equations with homogeneous Dirichlet and Neumann boundary conditions are established. The vanishing viscosity method is used to obtain the existence result. Afterwards, we formulate the optimal control problem in two cases. Firstly, we suppose that this biological species causes damage to environment (e.g. forest, agriculture): the optimal control is the trapping rate and the cost functional is a combination of damage and trapping costs. Secondly, an optimal harvesting control of a biological species is considered: the optimal control is a distribution of harvesting effort on the biological species and the cost functional measure the difference between economic revenue and cost. The existence and the condition of uniqueness of the optimal solution are obtained. A nonlinear optimality system is derived, characterizing the optimal control.     

Optimal Harvesting in an Age-Structured Predator–Prey Model

We investigate optimal harvesting control in a predator–prey model in which the prey population is represented by a first-order partial differential equation with age-structure and the predator population is represented by an ordinary differential equation in time. The controls are the proportions of the populations to be harvested, and the objective functional represents the profit from harvesting. The existence and uniqueness of the optimal control pair are established.     

OPTIMAL HARVESTING OF A SPATIALLY EXPLICIT FISHERY MODEL

Abstract We consider an optimal fishery harvesting problem using a spatially explicit model with a semilinear elliptic PDE, Dirichlet boundary conditions, and logistic population growth. We consider two objective functionals: maximizing the yield and minimizing the cost or the variation in the fishing effort (control). Existence, necessary conditions, and uniqueness for the optimal harvesting control for both cases are established. Results for maximizing the yield with Neumann (no‐flux) boundary conditions are also given. The optimal control when minimizing the variation is characterized by a variational inequality instead of the usual algebraic characterization, which involves the solutions of an optimality system of nonlinear elliptic partial differential equations. Numerical examples are given to illustrate the results.     

Numerical Optimal Harvesting for an Age-Dependent Prey-Predator System

In this article, we develop a numerical study of an optimal harvesting problem for age-dependent prey-predator system. Here, the rates of growth and decay as well as the interaction effect between species are assumed to be depending on age, time and space. Existence, uniqueness, and necessary conditions for the optimal control are assured in case of a small final time T. The discrete parabolic nonlinear dynamical systems are obtained by using a finite difference semi-implicit scheme. Then a numerical algorithm is developed to approximate the optimal harvesting effort and the optimal harvest. Results of the numerical tests are given.     

Optimal harvesting for nonlinear age-dependent population dynamics

In this paper, we investigate an optimal harvesting problem for nonlinear age-dependent population dynamics. Using the concept of the normal cone, we also obtain the necessary conditions for optimality for the optimal control problem. Using Ekeland’s variational principle, we demonstrate the existence and uniqueness of solutions for the optimal control problem. Finally, we give the synthesis of the optimal feedback law.     

具有年龄结构的种群线性动力系统的最优收获控制问题

§ 1　Introduction and setting of the problemThe optimal control of age-dependent population dynamics has been intensivelystudied in the last two decades and there is now a vast stock of literature on the topic ofoptimal control problems ofage-structured population dynamics.(see [1 -9] ) .To the bestof our knowledge,the works of Brokate[3,4] are the firstto deal with this topic.Since then,many authors devote to the optimal harvesting problem.In this aspect,we refere to thefundamental papers o…     

Control problems of an age-dependent predator-prey system

This paper is concerned with optimal harvesting problems for a system consisting oftwo populations with age-structure and interaction of predator-prey. Existence and uniquenessof non-negative solutions to the system and the continuous dependence of solutions on controlvariables are investigated. Existence of optimal policy is discussed, optimality conditions arederived by means of normal cone and adjoint system techniques.     

具有年龄结构的线性周期种群动力系统的最优收获控制问题

研究一类具有年龄结构的线性周期种群动力系统的最优收获控制问题,即讨论了具有周期的生死率和周期变化的收获项的Lotka Mckendrick模型.利用Mazur's定理,作者证明了控制问题最优解的存在性,同时借助于法锥概念,还得到了控制问题最优解存在的必要条件。最后，在适当的假设下，得到了最优控制问题的唯一解。该文的结论推广了某些已有的结果.      

Periodic optimal control for parabolic Volterra-Lotka type equations

This paper considers the optimal harvesting control of a biological species, whose growth is governed by the parabolic diffusive Volterra-Lotka equation. We prove that such equation with L^∞ periodic coefficients has an unique positive periodic solution. We show the existence and uniqueness of an optimal control, and under certain conditions, we characterize the optimal control in terms of a parabolic optimality system. A monotone sequence which converges to the optimal control is constructed.