Stabilization for nonlinear systems via a limited capacity communication channel with data packet dropout

This paper addresses the stabilization problem for a class of nonlinear systems. It is assumed that the controller can only receive the transmitted sequence of finite coded signals via a limited digital communication channel. Both state and output feedback coder-decoder-controller procedures are proposed. Stabilization conditions involving the size of coding alphabet, the sampling period, system state growth rate and data packet dropout rate are obtained. Finally, an example is given to illustrate the design procedures and effectiveness of the proposed results.     

Nonsynchronized state estimation of uncertain discrete-time piecewise affine systems

This paper investigates the problem of robust H-infinity state estimation for a class of uncertain discretetime piecewise affine systems where state space instead of measurable output space partitions are assumed so that the filter implementation may not be synchronized with plant state trajectory transitions. Based on a piecewise quadratic Lyapunov function combined with S-procedure and some matrix inequality convexifying techniques, two different approaches are developed to the robust filtering design for the underlying piecewise affine systems. It is shown that the filter gains can be obtained by solving a set of linear matrix inequalities (LMIs). Finally, a simulation example is provided to illustrate the effectiveness of the proposed approaches.     

基于灰色关联度和SVM舰船设备维修费用预测

维修费用是舰船装备费用的重要组成部分,维修费用和影响费用的驱动因子之间直接的关系式很难确定,运用支持向量机回归可以很好的做到对维修费用的建模预测。为了解决支持向量机计算速度慢,效率低的问题,提出灰色关联度理论对费用相关费用驱动因子进行预处理,测试结果表明提高了SVM的效率,对SVM的泛化能力也有所提高。     

Robust design of feedback integrated with iterative learning control for batch processes with uncertainties and interval time-varying delays

A robust feedback integrated with iterative learning control (FILC) scheme for batch processes with uncertain perturbations and interval time-varying delay is developed. The batch process is modeled as a two-dimensional (2D) Rosser system with a delay varying in a range. The design of FILC scheme is transformed into a robust control problem of uncertain 2D system. New delay-range-dependent stability criteria and stabilization conditions are derived in terms of linear matrix inequalities (LMIs), which depend on not only the difference between the upper and lower delay bounds but also the upper delay bound of the interval time-varying delay. Parameterized characterizations for stabilizing the controller are given in terms of the feasibility solutions to the LMIs. Applications to injection velocity control show that the proposed FILC achieve the design objectives well.     

T–S fuzzy model-based tracking control of a one-dimensional manipulator actuated by pneumatic artificial muscles

Pneumatic artificial muscle (PAM) has highly nonlinear and time-varying behavior due to gas compression and nonlinear elasticity of the bladder containers. Hence, it is difficult to achieve excellent tracking performance when using classical control methods. This study proposes a Takagi–Sugeno (T–S) fuzzy model-based control for improving control performance. The proposed approach decomposes the model of a nonlinear system into a set of linear subsystems. This allows, the T–S fuzzy model-based controller to use simple linear control techniques providing a systematic framework for the design of a state feedback controller. Stability analysis is carried out using Lyapunov direct method. The powerful LMI Toolbox in MATLAB is employed to solve linear matrix inequalities (LMIs) to obtain the controller gains. Experimental results verified that the proposed controller can achieve excellent tracking performance under different disturbances.     

基于监督分类的震后高分辨率影像倒塌房屋快速识别

针对监督分类中样本设计与选取、关键特征提取两个关键环节,设计了多种不同样本提取方法和多种典型特征参数组合,对海地震后高分辨率影像倒塌房屋快速提取进行分析研究。结果表明,以倒塌样本与屋角样本作为训练样本,以灰度均值和灰度共生矩阵逆差矩作为参数组合,能够保证较好提取精度的同时,最大限度减少人工样本选取工作量,提高倒塌房屋快速提取效率。最后以该分类方法对玉树震后高分辨率影像的倒塌房屋进行自动识别,识别结果良好,进一步检验了该分类方法的有效性。     

3带紧支撑的正交小波

本文首先通过Householder矩阵扩充构造了3带紧支撑的正交小波．当尺度函数具有紧支撑对称正交性时,本文通过仿酉矩阵对称扩充构造了3带紧支撑对称的正交小波,并且研究了所构造对称小波的结构．所构造小波函数的支撑不超过尺度函数的支撑,构造方法容易推广到一般d带的情形．另外,本文还给出了容易实施的显式构造算法．最后,给出了构造算例．     

机会发现中简单场景构造方法研究

场景构造是机会发现过程中的关键活动之一。对机会发现场景的结构进行形式化描述,提出基于布尔相关矩阵并利用聚类分析的方法构造事件簇,进而实现机会发现简单场景构造的思想并给出实现方法。对机会发现场景构造方法性能的评估进行探讨,明确以效率系数作为机会发现场景构造方法的评估标准。实验表明,该方法的效率系数较高。     

关于计算矩阵指数的新思考

本文结合符号计算推出了一种计算有理矩阵指数的新方法,利用该方法可以计算出有理矩阵指数的一类精确表达式．这种方法已实现了程序化,并且可以推广到一般有理矩阵函数的计算．     

基于文件拆分与高斯消去的线性方程组求解

针对集群系统内存不足导致大规模矩阵无法调入的情况,设计并实现一种基于文件拆分与高斯消去的线性方程组求解算法,将大规模系数矩阵文件连续拆分为多个规模可控的子文件进行存储和计算,使服务器空闲内存小且具有较好的计算能力。在ABEEMσπ模型中的应用结果表明,当Altix3700服务器任务提交量大、CPU占有率高时,该算法仍可以计算出蛋白质分子的电荷分布。