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111.
G. Grammel 《Journal of Optimization Theory and Applications》1998,99(3):681-689
We consider the infinite-time optimal control problem of minimizing an average functional for nonlinear control systems. For controllable systems, we give an explicit estimate for the required period T of -suboptimal T-periodic orbits. Moreover, we show that controllable systems are characterized by the existence of periodic suboptimal trajectories for any average functional. 相似文献
112.
Tianxiao Wang 《Journal of Mathematical Analysis and Applications》2019,469(1):280-297
Stochastic linear quadratic optimal control problems are considered. A unified approach is proposed to treat the necessary optimality conditions of closed-loop optimal strategies and open-loop optimal controls. Notice that the former notion does not rely on initial wealth, while the later one does. Our conclusions of closed-loop optimal strategies are directly derived by suitable variational methods, the approach to which is different from [12], [11]. Moreover, the necessary conditions for closed-loop optimal strategies happen to be sufficient which takes us by surprise. Finally, two applications are given as illustration. 相似文献
113.
利用细致分析的方法对单种群时滞反馈控制生态系统进行研究,获得了该系统正解持久生存的充分条件. 相似文献
114.
Rajesh Dhayal Muslim Malik Syed Abbas Amar Debbouche 《Mathematical Methods in the Applied Sciences》2020,43(7):4107-4124
We study optimal control problems for a class of second-order stochastic differential equation driven by mixed-fractional Brownian motion with non-instantaneous impulses. By using stochastic analysis theory, strongly continuous cosine family, and a fixed point approach, we establish the existence of mild solutions for the stochastic system. Moreover, the optimal control results are derived without uniqueness of mild solutions of the stochastic system. Finally, the main results are validated with the aid of an example. 相似文献
115.
In this paper we consider a linear KdV equation posed on a bounded interval. We study the behavior of the cost of null controllability when two boundary controls are employed. By means of suitable Carleman inequalities and a new exponential dissipation estimate, we prove that uniform null controllability with respect to the dispersion coefficient holds, contrary to the case when one control is used at the left end-point of the interval. 相似文献
116.
Enrique Otárola 《Numerical Methods for Partial Differential Equations》2020,36(2):302-328
We propose and analyze an a posteriori error estimator for a partial differential equation (PDE)-constrained optimization problem involving a nondifferentiable cost functional, fractional diffusion, and control-constraints. We realize fractional diffusion as the Dirichlet-to-Neumann map for a nonuniformly PDE and propose an equivalent optimal control problem with a local state equation. For such an equivalent problem, we design an a posteriori error estimator which can be defined as the sum of four contributions: two contributions related to the approximation of the state and adjoint equations and two contributions that account for the discretization of the control variable and its associated subgradient. The contributions related to the discretization of the state and adjoint equations rely on anisotropic error estimators in weighted Sobolev spaces. We prove that the proposed a posteriori error estimator is locally efficient and, under suitable assumptions, reliable. We design an adaptive scheme that yields, for the examples that we perform, optimal experimental rates of convergence. 相似文献
117.
Stepanov-like pseudo almost periodic solutions for impulsive perturbed partial stochastic differential equations and its optimal control 下载免费PDF全文
This paper is mainly concerned with the Stepanov-like pseudo almost periodicity to a class of impulsive perturbed partial stochastic differential equations. Firstly, we prove the existence of $p$-mean piecewise Stepanov-like pseudo almost periodic mild solutions for the impulsive stochastic dynamical system in a Hilbert space under non-Lipschitz conditions. The results are obtained by using the fixed point techniques with fractional power arguments. Then the existence of optimal pairs of system governed by impulsive partial stochastic differential equations is also obtained. Finally, an example is provided to illustrate the developed theory. 相似文献
118.
Global Stability of a Stochastic Lotka-Volterra Cooperative System with Two Feedback Controls 下载免费PDF全文
In this paper, a class of Lotka-Volterra cooperation system and corresponding stochastic system with two feedback controls which are a?ected by all species are considered. We obtain some su?cient criteria for local stability and global asymptotic stability of equilibria of the systems. Our study shows that these equilibria could be globally stable by adjusting coe?cients of the feedback control variables and stochastic perturbation parameters. Numerical simulations are presented to demonstrate our main result. 相似文献
119.
120.
DNA extracted from forensic samples can be degraded and also contain co‐extracted contaminants that inhibit PCR. The effects of DNA degradation and PCR inhibition are often indistinguishable when examining a DNA profile. Two internal amplification controls (IACs) were developed to improve quality control of PCR using the AmpF?STR® SGM Plus® kit. The co‐amplification of these controls with DNA samples was used to monitor amplification efficiency and detect PCR inhibitors. IAC fragments of 90 and 410 bp (IAC90 and IAC410) were generated from the plasmid pBR322 using tailed primers and then amplified with ROX‐labelled primers. Co‐amplification of IAC90 and IAC410 was performed with varying amounts of template DNA, degraded DNA and DNA contaminated with humic acid, heme and indigo dye. Both IAC90 and IAC410 were successfully amplified with human DNA without significantly affecting the quality of the DNA profile, even with DNA amounts lower than 0.5 ng. In the presence of inhibitors, the IAC90 signal was still present after all human DNA loci fail to amplify; in contrast, the IAC410 signal was reduced or absent at low levels of inhibition. Amplification of the two IACs provided an internal PCR control and allowed partial profiles caused by inhibition to be distinguished from degraded DNA profiles. 相似文献