On algorithms for construction of all irreducible partial covers

Lower and upper bounds on the cardinality and the number of irreducible partial covers for almost all set cover problems are obtained. These bounds allow us to prove that there is no polynomial algorithm which for almost all set cover problems constructs all irreducible partial covers, but there exists a totally polynomial algorithm which constructs all irreducible partial covers for almost all set cover problems.     

拟人控制系统的结构分析

本文对拟人控制系统结构进行了深入地分析和探讨。构造了拟人控制系统的复杂结构,指出了系统是由多种元素和多种子系统构成的,且不同元素和不同大大小小的子系统彼此间相互作用和相互影响。并在此基础上,提出了拟人控制系统的基本结构和特殊基本结构。     

基于集合枚举树的关联规则生成算法

在经典算法中由频繁项集生成关联规则需要生成频繁项集的所有非空子集作为候选后件集。李雄飞对此做出改进,提出逐层搜索后件的宽度优先算法。求下集极大元的Boundary算法也可用于求所有关联规则后件。论文提出一个深度优先算法GRSET(GenerateRulesbyusingSet-EnumerationTree),该算法利用集合枚举树,按照深度优先的方法逐一找出所有关联规则后件并得到相应的关联规则。通过实验对这三种算法进行比较,结果显示GRSET算法效率较高。     

The marriage of research and practice [software research]

Some types of research are of interest to all software readers, and all types o f research are of interest to some software readers; but not all types of research are of interest to all Software readers. The key to success for IEEE Software, or any other publication trying to disseminate research results to practitioners, is to identify research that is of interest to "all Software readers.".     

剩余格上的模糊滤子和模糊同余关系

介绍了剩余格上的模糊同余关系和模糊滤子的定义,给出了剩余格上模糊滤子和模糊同余关系间的一一对应,证明了在剩余格上模糊滤子和模糊同余关系上定义适当的序关系可使它们是完备格同构。     

用分层关联方法求有向图中所有Hamilton回路的算法

首先建立了有向图中初级通路的关联关系,并对初级通路的关联关系进行了分析,得到了关于初级通路关联关系的一些重要结果．然后,对初级通路的关联关系进行了分级分层．在此基础上,设计了求有向图中所有Hamilton回路的算法．该算法利用长度为k的初级通路及其分层关联关系逐步求长度为k＋1的初级通路及其分层关联关系的方法,求得有向图的所有Hamilton回路．通过理论分析可以看到,所设计的算法与已有的求有向图的所有Hamilton回路的算法相比,避免了大量的重复计算,从而降低了算法复杂度,为求解Hamilton回路问题提供了新思路．     

IT支撑系统在综合性基地的总体布局

随着中国移动各个综合性基地逐渐投入使用,如何将现有支撑系统逐步集中到各个综合性基地成为关键问题。以IT支撑系统集中化为基本指导思想,以建立中国移动IT系统的大生产流水线为基本方向,分析IT支撑系统在基地间的总体布局规划,为基地建设规划提供参考。     

Cubic curve update

The author considers the problem of cataloging all the shapes that can be generated by a cubic equation. In response to a letter commenting on an earlier column, he corrects an error in his listing of all the combinations of factorizations that could make degenerate curves, pointing out that all type 5's are really the same shape and all type 7's are really the same shape. He provides additional considerations on the possible shapes of nondegenerate curves     

基于任务-资源图的AGVS循环死锁搜索算法的改进研究

针对AGVS中循环死锁搜索算法研究中存在的不能搜索全部的循环死锁的问题,利用任务-资源图提出一个改进算法.改进算法如下:首先,根据AGV的相对位置关系和执行任务的情况,利用任务-资源图(Task-Resource graph,T-R图)对AGVS进行建模,然后根据循环死锁的T-R图特征,在每一个状态时刻下的T-R图使用图的强连通分支理论搜索循环死锁.当访问完所有状态时刻下的T-R图,也就找到了AGVS中的所有循环死锁.算例验证与理论分析均说明改进算法可以搜索到全部类型的循环死锁,解决了原算法存在的不足.根据改进算法开发的控制规则,可以有效避免新循环死锁的产生.同时指出,对改进算法稍加修改,可以找到AGVS中所有的循环死锁和非循环死锁.     

基于改进SAM的高光谱影像混合像元分解算法研究

将传统遥感图像分类方法中的光谱角度制图法(Spectral Angle Mapping-SAM)加以变换,改进为一种符合全约束条件下的高光谱遥感图像的混合像元分解模型.新算法在端元丰度比例满足全约束的条件下,通过逼近的方法寻找一种端元丰度的比例组合,使测试光谱与目标光谱的广义夹角最小,从而认为该比例组合就是混合像元分解...     

信念修正的完全和可操作的方法

给出了命题逻辑上信念修正的两种可操作的完全方法.首先对R-演算的规则进行了修改,使得对任何一个极大协调的子集都通过这组规则得到.然后,给出了求得所有的极小不协调子集的一组规则.最后,给出一个过程,该过程能求得所有的极大协调子集.因为这两种方法都能求得所有的极大协调子集,所以把它们称为完全的.     

唐卡图像复杂破损区域的修复

为了解决唐卡图像复杂破损区域修复的一类实际工程问题,从唐卡图像复杂破损区域的检测分割、误检测破损区域的屏蔽、各破损区域的定位惟一化、修复块修复优先级的确定、样本块的检索,到各破损区域中既定修复块的修复等一系列的过程与工程技术,详细地介绍了该类唐卡灰度图像与彩色图像复杂破损区域的修复技术,并给出了相应的修复结果.     

The undecidability of the unrestricted modified edit distance

We define the unrestricted modified edit distance based on the modified edit distance defined by Galil and Giancarlo (1989) where the cost of substring deletions and insertions are contextsensitive and the cost of character substitutions are context-free. The modified edit distance is the minimum cost of converting a string X to a string Y where the sequence of edit operations has the property that all substring deletions precede all character substitutions and all character substitutions precede all substring insertions. Note that the modified edit distance does not satisfy the triangle inequality. We show that the problem of finding the unrestricted modified edit distance which is the minimum cost over all edit sequences (without these constraints) of converting X to Y is undecidable.     

String stability of interconnected systems

Introduces the notion of string stability of a countably infinite interconnection of a class of nonlinear systems. Intuitively, string stability implies uniform boundedness of all the states of the interconnected system for all time if the initial states of the interconnected system are uniformly bounded. It is well known that the input output gain of all the subsystems less than unity guarantees that the interconnected system is input-output stable. The authors derive sufficient (“weak coupling”) conditions which guarantee the asymptotic string stability of a class of interconnected systems. Under the same “weak coupling” conditions, string-stable interconnected systems remain string stable in the presence of small structural/singular perturbations. In the presence of parameter mismatch, these “weak coupling” conditions ensure that the states of all the subsystems are all uniformly bounded when a gradient-based parameter adaptation law is used and that the states of all the systems go to zero asymptotically     

基于局部重配置的FPGA互连测试诊断

针对FPGA互连开关的常开、常闭、线段的开路、常0、常1故障,以及连接于同一开关矩阵的互连线段桥接故障的测试诊断问题,提出一种自动生成与应用无关的测试配置进行故障诊断的方法。通过对布线资源图中节点分方向遍历、生成全局和局部测试配置,用JTAG施加测试激励和回读结果。实验结果证明只需要较少配置时间就能够使互连故障覆盖率达到100%。     

Controller parametrization for time-varying multirate plants

The authors obtain a parametrization of all stabilizing controllers for a given discrete-time time-varying linear finite-dimensional multirate system. The parametrization is a natural extension of the Youla parametrization of all stabilizing controllers to the setting of multirate systems. The set of all stabilizing controllers is shown to be the set of all closed-loop systems obtained by terminating a fixed two-port multirate system in a stable multirate system. State-space formulas for the parametrization are also given     

二维加窗全相位图像卷积滤波模板的设计

基于全相位数据空间的概念以及一种二维加窗全相位图像滤波模板的设计,给出了一修正的二维全相位图像卷积滤波模板设计方法。方法在用全相位概念设计滤波模板中充分考虑了用DFT和循环卷积表达线性卷积时的等价性条件,以确保待设计的全相位滤波器的频率响应特性与给定的原型滤波器的频率特性矩阵有更好的相关性和一致性。实验表明,该全相位滤波模板与已有的二维全相位图像滤波模板比较,有过渡带的宽度窄、滚降陡峭,阻带衰减小等特点,可以进一步有效消除方块效应,提高滤波处理后图像的质量。     

基于Delphi的数据库图片插入新方法

随着科学技术的发展,人们越来越多地利用计算机管理相关事宜,希望能将所有多媒体文件存储在数据库中。然而,在实现的过程中,将多媒体文件插入到数据表格中又是一个比较头疼的问题。文中利用Delphi作为界面开发工具,提出了一个将图片插入到数据库中的新方法：     

基于痕迹的特征模型解释技术研究

提出了一种基于痕迹的特征模型多重解释新方法,通过一次分解两次组合形成零件所有可能的制造特征模型,首先,制造特征模型中的特征被分解为最小国呀体;然后利用残留在最小加工体中的特征痕迹,重构零件所有可能的制造特征;根据制造特征模型的存在条件,建立制造特征模型方程,该多解方程的解就是零件制造特征模型的多重解释。     

Diamond and simplex stability regions

Diamond and simplex models are useful in dealing with systems under parameter perturbations. A diamond (simplex) stability region  is an open set in the complex plane with the property that if the zeros of all vertex polynomials of any diamond (simplex) family are all in , then the zeros of all the polynomials of this family are all in . It is shown that some typical stability regions used in control systems design are diamond (simplex) stability regions. Some discussions and extensions are also presented.