Support vector machine ensemble using rough sets theory

A support vector machine （SVM） ensemble classifier is proposed. Performance of SVM trained in an input space eonsisting of all the information from many sources is not always good. The strategy that the original input space is partitioned into several input subspaces usually works for improving the performance. Different from conventional partition methods, the partition method used in this paper, rough sets theory based attribute reduction, allows the input subspaces partially overlapped. These input subspaces can offer complementary information about hidden data patterns. In every subspace, an SVM sub-classifier is learned. With the information fusion techniques, those SVM sub-classifiers with better performance are selected and combined to construct an SVM ensemble. The proposed method is applied to decision-making of medical diagnosis. Comparison of performance between our method and several other popular ensemble methods is done. Experimental results demonstrate that our proposed approach can make full use of the information contained in data and improve the decision-making performance.     

AOI交会触发服务器消息过滤方法

针对分布式虚拟环境(DVE)系统中服务器为系统性能瓶颈问题,提出了一种新的基于DVE系统化身兴趣区域(AOI)交会触发的服务器消息过滤方法.较之于传统的基于AOI方法的服务器消息优化方法,它通过在客户之间直接进行消息交互而减少客户与服务器之间的通信数量,并最终减少服务器的通信负载.针对该方法进行了理论分析,一系列的仿真实验也验证了理论的正确性.     

基于变分贝叶斯理论的不确定厚尾噪声滤波方法

为了解决非线性滤波中量测噪声呈厚尾分布且统计特性不确定的问题,提出一种基于Pearson Type VII分布的自适应滤波算法.针对传统鲁棒卡尔曼滤波器因尺度矩阵和自由度参数固定不变而无法自适应调整的问题,以容积卡尔曼滤波器为基础,选择Pearson Type VII分布对厚尾噪声进行建模,将传统鲁棒滤波固定自由度参数的估计转化为Pearson Type VII分布中可自适应调整的双自由度参数的估计,并通过inverse Wishart和Gamma分布描述尺度矩阵、双自由度参数和辅助参数的先验分布,利用遗忘因子对各参数进行时间更新;基于变分贝叶斯理论,对系统状态、尺度矩阵、双自由度参数和辅助参数形成的联合后验概率密度函数进行变分迭代,实现对系统状态和未知厚尾噪声的联合估计.仿真结果表明,在不确定厚尾噪声条件下,本文算法的滤波精度高于传统鲁棒容积卡尔曼滤波.     

带有等式状态约束的多传感器数据融合算法

在状态估计理论的实际应用中,状态向量常常包含可以预先获知的约束信息,有效地利用这些先验信息可以进一步明确状态元素之间的关系,理论上可以提高对系统的状态估计精度.针对约束滤波的已有研究成果,将其引入到多传感器系统,提出了约束系统多传感器数据融合算法.通过建立线性等式约束方程,将传统卡尔曼滤波结果投影到约束子空间,然后对局部传感器的约束滤波结果采用分布式最优加权融合,并且通过协方差匹配技术检测观测数据异常的传感器,使之不参与到数据融合中.仿真结果表明,约束系统分布式加权融合算法的有效性和可行性,并且比集中式融合算法具有更好的稳定性.     

An IEEE 802.3 Compatible Real Time Medium Access Control with Length-based Priority

IntroductionEthernet has become the most successful LANtechnology today .It is even regarded as the core to conceiveunified data communication systemin the future . However ,due to the non-deterministic essence of CSMA/CD,Ethernetis unsuitable for applications with stringent ti me constrains ,as inindustrial floors , where violation of such requirementswill result in great degradation of system performance oreven make whole systemparalyzed .Determinismproblemhas been studiedinthelast decad…     

积分对象的预测函数控制及其性能分析

基于过程脉冲响应设计预测函数控制器,针对积分过程输入端受到干扰后难以跟踪设定值的缺点,运用最优控制思想设计抗干扰控制器,所设计系统具有双自由度的控制结构.所提算法能同时适用于反向响应积分对象和大时间滞后积分对象的控制.仿真实验表明,该方法对过程参数摄动具有良好的鲁棒性及抑制外界干扰的能力.     

Robust H∞ Filter Design for a Class of Uncertain Linear Systems with Time—delayed Measurement

A robust H∞ approach to filtering for a class of uncertain linear systems with time-delayed measurement is investigated.The parameter uncertainties are described by real time-varying norm-bounded form.A methodology is developed for designing linear filters such that the filtering process remains robustly stable and the transfer function from the disturbance inputs to error state outputs meets the prescribed H∞-bound constraints.The filter can be obtained and parameterized by solving two Riccati equations based on the lemma of robust stability for control system with delay.Simulation example proves the method to be effective and feasible.     

Robust H∞ filter design for uncertain nonlinear discrete systems with state delay

In this paper, we address the problem of robust H∞ filter design for a class of nonlinear discrete-time systems with norm-bounded parameter uncertainty, unknown state delay, and unknown nonlinear disturbance. Firstly, the sufficient condition of the existence of the robust filter is analyzed by the modified Riccati inequalities, such that the filtering process remains robustly stable and a prescribed H∞ performance lever is achieved. Then the filter is characterized in the terms of positive solutions of two algebraic Riccati-like equations, irrespective of the uncertainties, time delays and nonlinearities. The simulation example further shows the validity and the applicability of the proposed approach.     

基于数据驱动的核电设备状态评估研究综述

核电设备全生命周期的状态评估对提高核电厂安全性、经济性影响重大.以往国内核电厂对系统、设备、构筑物的运维评估手段多依赖于设备自身报警机制、简单阈值判断或者现场工程师经验.随着在线监测系统在核电厂的应用实施和海量设备运行数据的积累,利用数据驱动技术进行设备健康状态评估已经成为行业关注重点.对此,介绍核电在线监测系统现状,...     

一类非线性时滞不确定性系统的鲁棒H∞滤波

研究含有状态时滞的非线性不确定性系统的鲁棒H∞滤波器设计问题。利用修正的Riccati型不等式分析了使滤波系统渐近稳定、且从噪声输入到误差输出的传递函数的H∞范数小于指定上界的充分条件，通过两个代数Riccati方程的正定解参数化表示了该滤波器。滤波器的设计过程和结构均是与状态时滞的大小、非线性扰动以及不确定性的参数无关的。仿真试验进一步表明了设计方法的有效性和可行性。