随机递归最优控制和混合最优控制问题

对随机递归最优控制问题即代价函数由特定倒向随机微分方程解来描述和递归混合最优控制问题即控制者还需 决定最优停止时刻, 得到了最优控制的存在性结果. 在一类等价概率测度集中,还给出了递归最优值函数的最小和最大数学期望.     

一类带停时的最优控制策略研究

利用随机分析的知识及最优控制理论,讨论了一类带停时随机控制的折扣费用模型,将原模型中费用结构中的R-S积分的被积函数同上1推广为满足某些条件的一般函数,推广后的模型更具一般性.针对不同参数,证明了最佳控制的存在性,并刻划了不同初始状态下,最优控制策略的结构及最佳费用函数的形式.     

随机SIRS模型拟最优控制存在的充分条件

通常的流行病模型参数都是确定的,但由于各种不确定因素的影响,模型的参数很难准确的得到.本文讨论一类不确定参数随机SIRS传染病模型的拟最优控制,目标函数为治疗疾病的过程中所花费的成本尽可能小.根据伴随方程的估计值,给出拟最优控制的误差估计.利用Hamiltonian函数建立了拟最优控制的充分条件,并通过数值算例验证了控制变量对疾病的影响.     

含有随机波动的非线性的最优投资和消费模型

在连续时间模型假设下,研究风险资产价格服从一个带有随机波动的几何布朗运动的最优消费和投资问题．首先建立了最优消费和投资同题随机最优控制数学模型;然后运用随机最优控制理论,得到了最优投资和消费随机最优控制问题的值函数所满足的线性抛物线偏微分方程和非线性抛物线偏微分方程．     

线性二次型随机最优控制的样条 RT 逼近

<正> 本文给出线性二次型随机最优控制问题的一种数值解法.这种方法称为样条函数Ritz-Trefftz 逼近方法,W.E.Bosarge.JR.和 O.G.Johnson 成功地用来解决确定性的LQ 最优控制问题.后来这种思想被应用于延迟系统.本文证明,它也能直接应用于包括工程上最重要的 LQG 问题在内的线性二次型随机最优控制.     

线性脉冲控制系统的能控性与最优控制

首先讨论了一类线性随机脉冲控制系统的精确能控性质,给出了该类控制系统的脉冲精确能控的等价的代数判据.然后提出了一个确定性的二维线性脉冲控制系统的时间-脉冲强度最优控制问题;利用动态规划原理,给出了脉冲最优控制的反馈形式和值函数的显式表达式;说明了值函数在整个平面上是连续的,在左右两个半平面的内部还是连续可微的.     

最优控制罚函数方法的统一性

本文把由D.L.Russell所提出的最优控制问题的Ⅰ型和Ⅱ型罚函数拓广和统一了起来:提出了一种外罚函数,从而解决了D.L.Russell提出的是否能找到一种不需要从内部趋近的条件的Ⅰ型罚函数列的问题;用统一的方法提供了若干充分和充要条件处理带罚函数的最优控制问题趋于原来的最优控制问题;还指出了非线性规划问题中若干重要的常用的罚函数恰好也是最优控制问题的罚函数。     

带停时的奇异型随机控制问题研究

利用随机分析的知识及最优控制理论,推广了一类带停时的随机控制问题,针对不同参数,证明了最佳控制的存在性,分两种情况给出了最佳控制的存在区域,并给出了不同初始状态下,最佳控制的结构和最佳费用函数.由于将原模型中费用结构中的R-S积分的被积函数由1推广为满足某些条件的一般函数,所以推广后的模型更具一般性.     

BSDE在跳框架下的风险敏感控制问题中的应用

本文研究了由带跳的随机微分方程驱动的风险敏感控制问题.利用测度变换和带跳的二次增长的倒向随机微分方程,证明了此问题最优控制的存在性,并通过相应倒向随机微分方程解的初值给出了此问题的值函数.     

对偶模型中带指数或线性罚函数的最优分红问题（英文）

本文研究了带罚函数的对偶模型的最优分红问题.假设当公司的盈余资金为负值时,公司不会发生破产,但是会进行相应的惩罚,惩罚金额取决于公司的余额水平.利用随机最优控制方法和动态规划原则,得到了最优化问题的HJB方程及其验证定理.最后,当收益服从指数分布时,得到了带指数罚函数和带线性罚函数两种情形各自的最优分红策略及最优值函数的解析式.     

一类非线性奇异最优控制问题的离散解法

本文研究非线性奇异最优控制问题的离散解法。利用在每个“小”时间区间上的积分形式来刻画奇异最优控制的特征,并构造了求解问题的差分方程,同时建立预估、校正格式给出了最优控制近似解的计算方法。     

Singular optimal controls of stochastic recursive systems and Hamilton–Jacobi–Bellman inequality

In this paper, we study the optimal singular controls for stochastic recursive systems, in which the control has two components: the regular control, and the singular control. Under certain assumptions, we establish the dynamic programming principle for this kind of optimal singular controls problem, and prove that the value function is a unique viscosity solution of the corresponding Hamilton–Jacobi–Bellman inequality, in a given class of bounded and continuous functions. At last, an example is given for illustration.     

奇异系统的最优调节器

奇异系统(singular systems)在工程、经济、生态等领域方面,有着广泛的背景与深远的意义.近几年来,作为控制系统的一个非常活跃的分支出现于自动控制界.国内外许多学者在这方面做了不少工作.文献[1]讨论了奇异系统使二次性能指标取极小的最优调节问题.利用奇异系统解     

具有有限燃料的奇异型最佳随机控制问题之推广

本文推广了有限燃料情况下的奇异型随控制模型，对推广后的模型求出了最佳费用函数的结构表达式及最佳控制的存在条件，且当最佳控制存在时具体地构造出了该最佳控制。     

On solvability of a two-sided singular control problem

We study a two-sided singular control problem in a general linear diffusion setting and provide a set of conditions under which an optimal control exists uniquely and is of singular control type. Moreover, under these conditions the associated value function can be written in a quasi-explicit form. Furthermore, we investigate comparative static properties of the solution with respect to the volatility and control parameters. Lastly we illustrate the results with two explicit examples.     

Necessary and Sufficient Optimality Conditions for Regular–Singular Stochastic Differential Games with Asymmetric Information

We consider a class of regular–singular stochastic differential games arising in the optimal investment and dividend problem of an insurer under model uncertainty. The information available to the two players is asymmetric partial information and the control variable of each player consists of two components: regular control and singular control. We establish the necessary and sufficient optimality conditions for the saddle point of the zero-sum game. Then, as an application, these conditions are applied to an optimal investment and dividend problem of an insurer under model uncertainty. Furthermore, we generalize our results to the nonzero-sum regular–singular game with asymmetric information, and then the Nash equilibrium point is characterized.     

Optimal Control for the Degenerate Elliptic Logistic Equation

We consider the optimal control of harvesting the diffusive degenerate elliptic logistic equation. Under certain assumptions, we prove the existence and uniqueness of an optimal control. Moreover, the optimality system and a characterization of the optimal control are also derived. The sub-supersolution method, the singular eigenvalue problem and differentiability with respect to the positive cone are the techniques used to obtain our results.     

Singular mean-field control games

This article studies singular mean field control problems and singular mean field two-players stochastic differential games. Both sufficient and necessary conditions for the optimal controls and for the Nash equilibrium are obtained. Under some assumptions the optimality conditions for singular mean-field control are reduced to a reflected Skorohod problem, whose solution is proved to exist uniquely. Motivations are given as optimal harvesting of stochastic mean-field systems, optimal irreversible investments under uncertainty and mean-field singular investment games. In particular, a simple singular mean-field investment game is studied, where the Nash equilibrium exists but is not unique.     

Optimal Control for the Degenerate Elliptic Logistic Equation

We consider the optimal control of harvesting the diffusive degenerate elliptic logistic equation. Under certain assumptions, we prove the existence and uniqueness of an optimal control. Moreover, the optimality system and a characterization of the optimal control are also derived. The sub-supersolution method, the singular eigenvalue problem and differentiability with respect to the positive cone are the techniques used to obtain our results.     

Some results on pointwise second-order necessary conditions for stochastic optimal controls

The purpose of this paper is to derive some pointwise second-order necessary conditions for stochastic optimal controls in the general case that the control variable enters into both the drift and the diffusion terms. When the control region is convex, a pointwise second-order necessary condition for stochastic singular optimal controls in the classical sense is established; while when the control region is allowed to be nonconvex, we obtain a pointwise second-order necessary condition for stochastic singular optimal controls in the sense of Pontryagin-type maximum principle. It is found that, quite different from the first-order necessary conditions, the correction part of the solution to the second-order adjoint equation appears in the pointwise second-order necessary conditions whenever the diffusion term depends on the control variable, even if the control region is convex.