Exponential stability of stochastic singular delay systems with general Markovian switchings

In recent years, Markovian jump systems have received much attention. However, there are very few results on the stability of stochastic singular systems with Markovian switching. In this paper, the discussed system is the stochastic singular delay system with general transition rate matrix in terms of uncertain and partially unknown transition rate matrix. The aim is to answer the question whether there are conditions guaranteeing the underlying system having a unique solution and being exponentially admissible simultaneously. The proposed results show that all the features of the underlying system such as time delay, diffusion, and general Markovian switchings play important roles in the system analysis of exponential admissibility. A numerical example is used to demonstrate the effectiveness of the proposed methods. Copyright © 2014 John Wiley & Sons, Ltd.     

On the forced vibration of the fiber partially immersed in fluid

In this paper an experimental and theoretical investigation of the forced vibration of a partially immersed fiber has been carried out. An optical method utilizing a forward light scattering pattern has been used to detect a small (<1.0 μm) vibration amplitude of the fiber. The physical and mathematical model of the partially immersed fiber vibration has been put forward. Based on an analytical solution of the model, natural frequencies of the partially immersed fiber vibration have been found; they are consecutive positive roots of the transcendental equation. An “effective” speed of the wave propagation over the fiber has been introduced, which allows one to find the physical meaning of normal modes of the partially immersed fiber vibration. Theoretical predictions agree well with experimental data. The sensor exhibits an excellent sensitivity and could be used for measuring physical properties of fluids and liquid level.     

基于观测的POMDP 优化算法及其仿真

在分析马尔可夫决策过程（Markov Decision Process, MDP）性能灵敏度的基础上,讨论了部分可观 测马尔可夫决策过程（Partially Observable Markov Decision Process, POMDP）的性能优化问题．给出了POMDP 性能灵敏度分析公式,并以此为基础提出了两种基于观测的POMDP 优化算法：策略梯度优化算法和策略迭 代优化算法．最后以准许控制问题为仿真实例,验证了这两个算法的有效性．     

多高斯关联扭曲光束在GRIN光纤中的轨道角动量演化

轨道角动量(orbital angular momentum, OAM)的引入丰富了光通信领域内的调制维度,为寻找更高效快捷的通信方式提供了新思路,相较于传统携带涡旋相位的涡旋光束,部分相干扭曲光束携带的OAM性质更为复杂。本文针对椭圆多高斯关联扭曲光束在梯度折射率(gradient-index, GRIN)光纤中的OAM传输,基于GRIN光纤的ABCD光学传输矩阵,着重分析了多高斯关联扭曲光束在GRIN光纤传输的OAM的传输演化特性。研究结果表明,光束的光强、OAM通量密度以及归一化OAM通量密度在光纤传输过程中均呈现周期性变化,通过对关联结构以及扭曲因子的调控不仅可以改变光束OAM通量密度的分布,还可以调控单光子携带OAM的大小。本文的研究有助于丰富扭曲部分相干光束在GRIN光纤中传输的理论结果,在光纤通信中具有潜在的应用前景。     

聚焦部分相干平顶涡旋光束对瑞利粒子的捕获

基于广义惠更斯-菲涅尔原理和瑞利散射理论,推导了聚焦部分相干平顶涡旋(partially coherent flat-topped vortex, PCFTV)光束作用在瑞利微粒上辐射力的表达式,主要研究聚焦PCFTV光束对不同折射率的两种粒子的捕获情况。研究结果表明,聚焦PCFTV光束可以在焦点处捕获高折射率和低折射率的粒子。随着光束阶数的增大以及相关长度的减小,光束对微粒的捕获能力增强。所得结果对PCFTV光束应用于光学操控具有一定的意义。     

Event-triggered-based integral reinforcement learning output feedback optimal control for partially unknown constrained-input nonlinear systems

In this paper, an adaptive output feedback event-triggered optimal control algorithm is proposed for partially unknown constrained-input continuous-time nonlinear systems. First, a neural network observer is constructed to estimate unmeasurable state. Next, an event-triggered condition is established, and only when the event-triggered condition is violated will the event be triggered and the state be sampled. Then, an event-triggered-based synchronous integral reinforcement learning (ET-SIRL) control algorithm with critic-actor neural networks (NNs) architecture is proposed to solve the event-triggered Hamilton–Jacobi–Bellman equation under the established event-triggered condition. The critic and actor NNs are used to approximate cost function and optimal event-triggered optimal control law, respectively. Meanwhile, the event-triggered-based closed-loop system state and all the neural network weight estimation errors are uniformly ultimately bounded proved by Lyapunov stability theory, and there is no Zeno behavior. Finally, two numerical examples are presented to show the effectiveness of the proposed ET-SIRL control algorithm.     

Optimal Control for Partially Observed Nonlinear Deterministic Systems with Fuzzy Parameters

In this paper we consider the control problem for a class of partially observed deterministic systems governed by nonlinear differential equations with fuzzy parameters. Using Takagi–Sugeno fuzzy model, we propose a linear (fuzzy) controller, driven by the output process, for controlling the system. Further, using calculus of variations, we have developed a set of necessary conditions on the basis of which optimal control can be determined. Based on these necessary conditions we have proposed a numerical algorithm for computing optimal control along with some numerical simulations to illustrate the effectiveness of the proposed (fuzzy) control scheme.     

横观各向同性土——半封闭隧道衬砌相互作用分析

土体在沉积过程中存在各向异性,将土体视为各向异性体更为合理。考虑土体和衬砌的相互作用,基于饱和多孔介质理论和弹性理论,在频率域内研究了简谐荷载作用下横观各向同性土———半封闭圆形隧道衬砌简谐耦合振动。通过衬砌内边界应力连续以及土体和衬砌界面处应力和位移协调,得到了饱和横观各向同性土和衬砌的位移、应力和孔压解析表达式。利用衬砌中流体速度和土体中流体速度相等,建立了隧道部分透水边界条件,得到了待定系数的具体表达式。数值算例分析了土体和衬砌物性和几何参数的影响,表明:横观各向同性面内的弹性模量对系统动力响应影响较大,而垂直于各向同性面内的弹性模量对系统动力响应影响较小。另外,相对渗透系数和衬砌厚度对响应幅值有很大影响,而衬砌泊松比对响应幅值影响较小。     

Some quadrature formulas for functions partially holomorphic with respect to each variable in a Jordan polydomain in C 2 and a complex double integral formula

In this paper, quadrature formulas with remaining term in integral form for functions partially holomorphic with respect to each variable in a Jordan polydomain in C ² and a complex double integral formula are given. For this, we used the Cauchy Integral formula for Jordan polydomain in C ².