一种基于流形学习的近红外光谱分析建模方法

近红外光谱分析的重要内容之一是基于校正样品集建立光谱和化学成分或类别之间的回归模型。流形学习是一类新的机器学习方法，它能够揭示出复杂数据的本质维数，提取最重要的特征信息，并用于建立回归或分类模型。文章以近红外光谱为研究对象，针对近红外光谱数据维数高、谱带归属难以确定等特点，基于流形学习中局部线性嵌入（LLE）算法的思想，提出了一种最小二乘局部加权回归（LS-LWR）建模方法。最后，利用各种浓度葡萄糖溶液的近红外光谱，对该方法进行了验证。同时建立主成份回归（PCR）和偏最小二乘回归（PLSR）模型，通过计算预测标准偏差（SEP）与LS-LWR模型进行比较。实验结果表明，LS-LWR模型有更好的预测效果，而且具有模型简单、稳定性好和计算省时等优点。     

Fuzzy Impulsive Control of Permanent Magnet Synchronous Motors

The permanent magnet synchronous motors （PMSMs） may experience chaotic behaviours with systemic parameters falling into a certain area or under certain working conditions, which threaten the secure and stable operation of motor-driven. Hence, it is important to study the methods of controlling or suppressing chaos in PMSMs. In this work, the Takagi-Sugeno （T-S） fuzzy impulsive control model for PMSMs is established via the T-S modelling methodology and impulsive technology. Based on the new model, the control conditions of asymptotieal stability and exponential stability for PMSMs have been derived by the Lyapunov method. Finaily, an illustrated example is also given to show the effectiveness of the obtained results.     

Exponential stability of cellular neural networks with multiple time delays and impulsive effects

In this work, the stability issues of the equilibrium points of the cellular neural networks with multiple time delays and impulsive effects are investigated. Based on the stability theory of Lyapunov-Krasovskii, the method of linear matrix inequality （LMI） and parametrized first-order model transformation, several novel conditions guaranteeing the delaydependent and the delay-independent exponential stabilities are obtained. A numerical example is given to illustrate the effectiveness of our results.     

变时延移动Ad-Hoc网络容量非合作规划博弈模型的渐近稳定性

移动Ad-Hoc网络容量的稳定性是保证其服务质量的关键性质之一.本文提出一种新颖的考虑时变传播时延的非合作规划博弈移动Ad-Hoc网络容量分析模型稳定性控制技术.首先求得加入时变传播时延项的非合作规划博弈移动Ad-Hoc网络容量分析模型的源节点发送流量速率演化方程组—–一类非线性时变时滞微分方程组,在此基础上采用描述器技术结合线性矩阵不等式技术得到该模型的渐进稳定性准则,并设计了模型稳定性控制的迭代算法.由于是基于等价模型变换,所提出的渐近稳定性判别准则具有较小的保守性.仿真实验验证了本算法的有效性.本建模与分析方法虽以具体的非合作规划博弈移动Ad-Hoc网络容量分析模型为例,但其可以应用于一般的移动Ad-Hoc网络容量稳定性控制问题.     

农产品价格的随机模型及风险度量

在连续时间模型的假设条件下 ,研究了农产品价格服从伊藤随机过程的数学期望及方差问题 .首先利用 Fok ker-Planck方程及偏微分方程 ,经过变形对由该扩散随机过程所描述的价格均值及风险进行了估计 ;然后给出了假设 Ito随机过程为稳态条件下的转移概率密度 ps的表达式 ,利用 ps求出相应的价格与风险值 .该模型也可用于风险投资等领域的研究 .     

Impulsive control of permanent magnet synchronous motors with parameters uncertainties

The permanent magnet synchronous motors (PMSMs) may have chaotic behaviours for the uncertain values of parameters or under certain working conditions, which threatens the secure and stable operation of motor-driven. It is important to study methods of controlling or suppressing chaos in PMSMs. In this paper, robust stabilities of PMSM with parameter uncertainties are investigated. After the uncertain matrices which represent the variable system parameters are formulated through matrix analysis, a novel asymptotical stability criterion is established. Some illustrated examples are also given to show the effectiveness of the obtained results.     

参数不确定永磁同步电机混沌的模糊控制

通过Takagi-Sugen控制技术，建立了参数不确定永磁同步电机的Takagi-Sugen模糊控制模型，然后利用矩阵分析和Lyapunov稳定性理论，得到了参数不确定永磁同步电机渐进稳定的充分条件，最后通过实例证实了结果的正确性，相比传统的模糊控制方法，基于Takagi-Sugen模型的模糊控制方法具有一定的优越性. 关键词： 混沌控制 Takagi-Sugen模型 模糊控制 永磁同步电机     

Fuzzy modeling and impulsive control of hyperchaotic Lü system

This paper presents a novel approach to hyperchaos control of hyperchaotic systems based on impulsive control and the Takagi-Sugeno （T-S） fuzzy model. In this study, the hyperchaotic Lu system is exactly represented by the T-S fuzzy model and an impulsive control framework is proposed for stabilizing the hyperchaotic Lu system, which is also suitable for classes of T-S fuzzy hyperchaotic systems, such as the hyperchaotic Rossler, Chen, Chua systems and so on. Sufficient conditions for achieving stability in impulsive T-S fuzzy hyperchaotic systems are derived by using Lyapunov stability theory in the form of the linear matrix inequality, and are less conservative in comparison with existing results. Numerical simulations are given to demonstrate the effectiveness of the proposed method.     

参数不确定永磁同步电机混沌的模糊脉冲控制

通过Takagi-Sugen控制技术和脉冲控制技术，建立了参数不确定永磁同步电机的Takagi-Sugen模糊脉冲控制模型，然后利用矩阵分析和Lyapunov稳定性理论，得到了参数不确定永磁同步电机渐进稳定和指数稳定的充分条件，最后通过实例证实了该结果的正确性，相比传统的控制方法，基于Takagi-Sugen模型的模糊脉冲控制方法具有一定的优越性. 关键词： 混沌控制 模糊控制 脉冲控制 永磁同步电机