Robust control of T‐S fuzzy systems with time‐varying delay using new approach

This paper aims to design a controller to robustly stabilize uncertain nonlinear systems with time‐varying delay and norm bounded uncertainties via Takagi–Sugeno (T‐S) fuzzy model. The stabilization conditions are given in the form of linear matrix inequalities using a single Lyapunov–Krasovskii functional (LKF) combining the introduction of some relaxation matrices and only one tuning parameter. In comparison with the existing techniques in the literature, the proposed approach has two major advantages. The first is the reduction of computational complexity when the number of IF‐THEN rules, r, is big. The second concerns the conservatism reduction. Several examples are given to show the effectiveness and the merits of the design procedure. Copyright © 2009 John Wiley & Sons, Ltd.     

一种多维并行报文分类算法

位并行、位向量和聚合位向量算法通过对多个域进行并行处理加快分类速度,但三者内存占用太大,不适用于大规则集。为此,提出一种压缩位并行算法,通过报文分类压缩每个域上的重复规则并重新组织规则集,从而缩短位图中位串的长度,减少内存空间的占用。实验结果证明,该压缩位并行算法在不影响运行速度的前提下,明显减少了空间占用。     

Fault containment in weakly stabilizing systems

Research on fine tuning stabilization properties has received attention for more than a decade. This paper presents probabilistic algorithms for fault containment. We demonstrate two exercises in fault containment in a weakly stabilizing system, which expedite recovery from single failures, and confine the effect of any single fault to the constant-distance neighborhood of the faulty process. The most significant aspect of the algorithms is that the fault gap, defined as the smallest interval after which the system is ready to handle the next single fault with the same efficiency, is independent of the network size. We argue that a small fault gap increases the availability of the fault-free system.     

基于DNA下推自动机二进制减法和乘法的实现

提出了基于DNA下推自动机二进制减法和乘法的实现方法.一位二进制借位减法,是通过预先构造好的DNA下推自动机模型在一个试管中以该模型的运行方式自动完成运算.m位二进制借位减法,是在一位二进制减法的基础上,按照从低位到高位的顺序,将低位产生的借位作为高位试管操作巾的输入符号串,从而完成高位的减法运算.两位二进制乘法中包含移位和加法操作,在两个试管中分别设计好DNA下推自动机模型,分别完成被乘数与乘数各位的移位操作,同时结合相应的生物操作,将其作为另一个试管加法操作中的输入符号串,则加法操作中产牛的结果即为所求.在此基础上,m位二进制乘法可通过移位操作的并行性和加法操作的串行性来完成运算.这些实现方法为DNA下推自动机实现基本的算术运算提供了比较完整的运算机制.     

基于卡诺图的三变量可逆逻辑综合算法

提出了一种基于卡诺图的可逆逻辑综合算法,该算法可以快速地求解带垃圾位的可逆逻辑综合问题。大量特定的可逆逻辑门都不可避免地带有一定的垃圾位, 如果使用真值表、置换群等经典可逆逻辑综合算法求解这些带垃圾位的可逆逻辑门,则因无法获得全局状态而很难得到结果。根据卡诺图的特点,将可逆逻辑问题分解为多个变量分别求解,无需关心全局状态。提出的卡诺图可逆逻辑综合算法 根据在卡诺图上的邻接性将3变量可逆逻辑问题划分为5个等价类;对每个等价类分别进行计算,在常数时间内解决了带垃圾位的可逆逻辑综合问题。     

基于GPS软件接收机的C/A码捕获算法

为了尽量减少导航电文数据比特跳变带来的影响,在基于FFT的并行码相位搜索算法的基础上,采用两相邻毫秒数据进行捕获,再利用DFT细化频率估计,得到C/A码相位和较精确的载波频率。利用实际采集的数据进行实验,结果证实了该方法能快速有效地对C/A码进行捕获,为后续跟踪环路提供了良好的初始条件。     

一种基于位向量的位置索引压缩方法*

为了缓解大规模分布式系统中共享资源位置索引信息带来的存储压力,提出一种基于位向量的信息压缩方法。该方法建立在区/站/节点三级分层和区间对等的混合覆盖网结构上,通过在两级代理节点的有序子节点集和一定位数的位向量间建立映射关系,进而把冗余资源的位置索引信息汇聚到一条记录,逆向的位向量查询则可获取副本的分布信息。实验表明,该压缩方法达到了较高的记录压缩比,同时对提高副本定位效率起到了一定的作用。     

改进的矩形NAM图像表示算法

为了提高图像的表示效率,提出了一种改进的矩形非对称逆布局模式表示模型(NAM)图像编码算法IRNAM。该算法采用双矩形子模式对灰度图像进行表示,结合位平面优化策略,并顺序存储各子模式的数据,使得子模式数目大幅减少。实验结果表明：与矩形NAM算法和其他改进的NAM算法相比, IRNAM算法使表示图像的子模式数明显减少了,从而有效地节省了数据存储空间,是一种高效的图像表示方法。     

浮点格式转换的分析与实现

针对不同类型浮点数表示不尽相同,不同机型浮点格式的转 换不仅涉及阶码和尾数的表达,还涉及到浮点数存储的方式、位和位域操作等实现起来较繁 琐的问题,分析了其存储方式的异同,开发了一个CBitArray位数组类,结合VAX机型浮点数 与微机浮点数的转换,说明了该方法可简洁方便地实现不同类型浮点格式的转换。     

A study on a quantum-inspired evolutionary algorithm based on pair swap

A quantum-inspired evolutionary algorithm (QEA) is proposed as a stochastic algorithm to perform combinatorial optimization problems. The QEA is evolutionary computation that uses quantum bits and superposition states in quantum computation. Although the QEA is a coarse-grained parallel algorithm, it involves many parameters that must be adjusted manually. This paper proposes a new method, named pair swap, which exchanges each best solution information between two individuals instead of migration in the QEA. Experimental results show that our proposed method is a simpler algorithm and can find a high quality solution in the 0-1 knapsack problem. This work was presented in part at the 12th International Symposium on Artificial Life and Robotics, Oita, Japan, January 25–27, 2007