Impulse observability and impulse controllability of regular degenerate evolution systems

Impulse observability and impulse controllability of regular degenerate evolution systems are discussed by using functional analysis and operator theory in Banach space. Necessary and sufficient conditions for the impulse observability and impulse controllability of the system are obtained. This research is theoretically important for studying the design of the degenerate evolution system.     

Variational discretization for optimal control problems governed by parabolic equations

This paper considers the variational discretization for the constrained optimal control problem governed by linear parabolic equations. The state and co-state are approximated by Raviart- Thomas mixed finite element spaces, and the authors do not discretize the space of admissible control but implicitly utilize the relation between co-state and control for the discretization of the control. A priori error estimates are derived for the state, the co-state, and the control. Some numerical examples are presented to confirm thetheoretical investigations.     

基于时间-空间分数阶偏微分方程的图像去噪模型

为了在去噪的同时更多地保留图像的细节信息,将分数阶微积分理论和梯度下降流有效结合,提出了分数阶梯度下降流的概念,并证明了能量泛函的分数阶梯度下降流在一定微分阶次范围内是收敛的。在此基础上,将时间因素引入到改进的基于空间分数阶偏微分方程的去噪模型中,从而构建了基于时间-空间分数阶偏微分方程的去噪模型,该模型实现了在时间方向上和空间平面内的同时去噪。实验结果表明,提出的基于时间-空间分数阶偏微分方程的图像去噪模型较基于空间分数阶偏微分方程的图像去噪模型不仅可以提高信噪比,而且可以大幅减少图像获得最大信噪比所需要的迭代次数。     

分数阶线性系统的能观性研究

在对一类由分数阶线性微分方程描述的系统的能观性问题研究中,通过分数阶线性定常系统求解,给出了分数阶线性定常和时变系统一般解的统一表达式。在给出分数阶系统能观性定义的基础上,提出并证明了分数阶线性系统时变和定常系统能观性的充分和必要条件,以及分数阶线性定常系统的能观性判据,所得结论对分数阶控制系统的分析与综合是有益的。     

Research on controllability for a class of fractional-orderlinear control systems

1.INTRODUCTION Therealobjectsaregenerallyfractional[1],however,thecontrolsystemsusedsofarareallconsideredas integer ordersystems.Thereasonisthecomplexity andtheabsenceofadequatemathematicaltoolsfor fractional ordersystems.Fractionalcalculusisanatu ralextensionoftheclassicalmathematics.Thefrac tionalcalculustheorywasdevelopedbyalotofmath ematicians[2,3]andtheapplicationdomainsoffrac tionalcalculushaveincreasedsignificantly.Lasttwo decadestheknowledgewasappliedincontroltheory,whichconcerned…     

Leader selection for strong structural controllability of single-integrator multi-agent systems

This paper addresses the leader selection problem for strong structural controllability (SSC) of multi-agent systems (MASs). For a path-bud graph, it is proved that only one leader is required to guarantee the SSC of MASs. For a special type of topologies, based on the partition of the topology into disjoint pathes and path-buds, it is proved that the MASs is strongly structurally controllable if the root nodes of the pathes are selected as leaders. For general topologies, an algorithm is provided to determine the agents that can behave as leaders. For some special topologies, the minimum number of leaders guaranteeing the robust strong structural controllability (RSSC) of MASs is also obtained. Two examples are given to verify the effectiveness of the results.     

On controllability for stochastic control systems when the coefficient is time-variant

<正> This paper investigates the controllability problem of time-variant linear stochastic controlsystems.A sufficient and necessary condition is established for stochastic exact controllability,whichprovides a useful algebraic criterion for stochastic control systems.Furthermore,when the stochasticsystems degenerate to deterministic systems,the algebraic criterion becomes the counterpart for thecomplete controllability of deterministic control systems.     

数组微分方程组广义同步系统理论研究

实现数组微分动力系统广义同步是进行图像保密通信的前提。在引入映射在矩阵域中下降这一新定义的基础上,提出了一个实现数组微分动力系统广义同步的新定理,给出了广义系统初始条件选取的方法,据此可构造通过线性变换达到广义同步的数组微分动力系统,即理论上可以构造出图像保密通信的发射系统和接收系统。通过引入实例,说明该定理构造一个广义同步的数组微分动力系统。数值模拟结果结果表明,运用定理构造成的数组广义同步系统实现了混沌广义同步。     

结构元线性生成的模糊线性微分系统

主要目的是利用模糊结构元方法来解决模糊线性微分系统的模糊初值问题.首先，简单地介绍了模糊结构元方法，根据该方法定义了线性生成的模糊线性微分系统.其次，利用由模糊结构元线性表示的模糊值函数和模糊值函数的导数，研究了模糊线性微分系统的求解问题，给出了系统解存在的充要条件.最后，将给出一个实际例子，进一步表明了该方法的有效性.     

基于混合非线性偏微分方程扩散的可逆图像放大

综合应用冲激滤波器、改进的前向后向(forward and backward,FAB)扩散滤波器和全变差(total-variation,TV)扩散算法,提出一种双正交映射约束的混合偏微分方程扩散图像放大算法。改进的FAB滤波器能够很好地增强图像的小边缘,参数约束的冲激滤波器可增强图像的强边缘,基于水平集方法实现的TV扩散可以消除边缘的锯齿波,使边缘光滑,所提算法综合以上优点。利用退化模型的低通滤波器的双正交滤波器得到一个空域双正交映射,放大图像完全满足退化模型,使放大图像对于退化模型可逆。仿真实验表明,与其他算法相比,所提算法有较好的性能,得到的放大图像更加自然,在弱边缘和中等强度边缘都有更好的视觉效果。     

Novel time-frequency differential space-time modulation for multi-antenna OFDM systems

1.INTRODUCTIONRecently,there has been considerable interest in thewireless communication system with multiple trans-mit and receive antennas[1,2].So far,most researchon space-ti me modulation has assumed that accuratechannel esti mations are available at the receivers.Differential space-ti me(DST)modulationschemes were proposed to achieve diversity gainswithout channel state information(CSI)[3].DSTmodulation schemes allowfor slowly changing chan-nels that have to remaininvariant within…     

Almost sure and moment exponential stability of predictor-corrector methods for stochastic differential equations

This paper deals with almost sure and moment exponential stability of a class of predictor-corrector methods applied to the stochastic differential equations of Ito-type.Stability criteria for this type of methods are derived.The methods are shown to maintain almost sure and moment exponential stability for all sufficiently small timesteps under appropriate conditions.A numerical experiment further testifies these theoretical results.     

Validation for decision support systems: Recent developments and findings

This paper reviews earlier work on the validation of mathematical models and modeling within Decision Support Systems (DSS), in particular where the DSS were developed to support operations management. The authors found that little validation was carried out in practice. With this work as a base, reasons for the paucity of validation are advanced and comparisons with DSS developed to support marketing management are made. The case for a more appropriate methodology of validation is advanced.     

Novel method based on ant colony opti mization for solving ill-conditioned linear systems of equations

1 .INTRODUCTIONStudies have shownthat some systems are highlysen-sitive :a small perturbationin the data can result in alarge changeinthe solutions .Such systems are calledill-conditioned systems .Ill-conditionedlinear systemsof equations have a wide application in many fieldssuch asi magine processing,deconvolution, model pa-rameters esti mation.Because the condition number ofill-conditionedlinear systems of equationsis very big,the data error andthe rounding error inthe computa-tional p…     

Recent progress on space-borne microwave sounder pre-launch calibration technologies in China

The development processes and the application achievements of space-borne microwave sounder pre-launch calibration technologies in China are introduced briefly.Then,the general project plan for pre-launch calibration,the latest research achievements on the optimization and development of the microwave wide band calibration targets,emissivity measurement technologies and the system level uncertainty analysis of the laboratory,and the thermal/vacuum microwave sounder calibration system for"FY-3"meteorological satellite are reported,respectively.Finally,the key technological problems of the calibration technologies under researching are analyzed predictively.     

Recent progress on space-borne microwave sounder pre-launchcalibration technologies in China

The development processes and the application achievements of space-borne microwave sounder pre-launch calibration technologies in China are introduced briefly. Then, the general project plan for pre-launch calibration, the latest research achievements on the optimization and development of the microwave wide band calibration targets, emissivity measurement technologies and the system level uncertainty analysis of the laboratory, and the thermal/vacuum microwave sounder calibration system for ＂FY-3＂ meteorological satellite are reported, respectively. Finally, the key technological problems of the calibration technologies under researching are analyzed predictively.     

基于随机微分方程的股权拍卖报价策略及模型研究

拍卖是实现风险投资股权退出的方式之一.在风险投资股权拍卖交易中存在的信息不对称以及外部环境的不确定性使得外部投资者难以对风险企业股权准确地定价, 鉴于此,将股权竞买系统视为一个开放系统,运用随机微分方程来描述外部投资者的报价策略状态演变过程,在此基础之上构建风险投资退出股权拍卖模型,并探讨市场出清价格的形成机理及其信息公布程度、竞买人易受影响程度等因素的影响,最后运用变分法对风险投资家的期望收益进行了分析.     

Razumikhin-type theorems for asymptotic stability of impulsive stochastic functional differential systems

<正>In this paper,we investigate the pth moment uniformly asymptotic stability of impulsive stochastic functional differential systems by extending some Razumikhin-type theorems.Based on the Lyapunov functions and Razumikhin techniques,some criteria are established and their applications to impulsive stochastic delay systems are proposed.An illustrative example shows the effectiveness of our results.     

A simplified rational representation for positive-dimensional polynomial systems and SHEPWM equations solving

The paper is concerned with the improvement of the rational representation theory for solving positive-dimensional polynomial systems. The authors simplify the expression of rational representation set proposed by Tan and Zhang (2010), obtain the simplified rational representation with less rational representation sets, and hence reduce the complexity for representing the variety of a positive-dimensional ideal. As an application, the authors compute a “nearly” parametric solution for the SHEPWM problem with a fixed number of switching angles.     

A triangular decomposition algorithm for differential polynomial systems with elementary computation complexity

In this paper, a new triangular decomposition algorithm is proposed for ordinary differential polynomial systems, which has triple exponential computational complexity. The key idea is to eliminate one algebraic variable from a set of polynomials in one step using the theory of multivariate resultant. This seems to be the first differential triangular decomposition algorithm with elementary computation complexity.