不相容决策表分解的若干性质

本文指出文献[2]中一个提取不相容决策表决策规则的分解处理方法存在的错误，并且分析错误产生的原因．在此基础上，本文进一步对这种分解方法进行考察，给出了原始不相容决策表和分解后的子决策表之间有关核属性和属性约简等方面的若干关系和性质。     

非线性不确定系统的鲁棒性研究

1　引言非线性不确定系统的鲁棒性研究 ,早期是以在匹配条件 (matching condition)和广义匹配条件下 ,设计控制器使闭环系统达到实际稳定 (practical stabitity)为主 [1～ 3 ] .近些年利用 H∞ 控制理论的结果 ,出现了对具有有界结构的非线性不确定系统的鲁棒性讨论 [4～ 9] .模有界结构条件下 ,非线性不确定系统的鲁棒性有可能达到使状态趋于平衡点 ,而非仅仅实际稳定 .在文献 [4]中所讨论的非线性系统 ,要求其非线性部分具有线性界 .文献 [5 ]首次将模有界结构条件引入到线性不确定系统的鲁棒性研究中 .文献 [6]进一步讨论了这一结构下的…     

基于可辨识矩阵和逻辑运算的属性约简算法的改进

首先,举例说明文献[1]中基于可辨识矩阵和逻辑运算的属性约简算法用于不相容决策表会产生错误的约简结果;随后,在分析错误产生原因的基础上给出一种改进算法,并借助实例验证了它的有效性;最后,通过分析可辨识矩阵的结构,说明了改进算法与文献[2]基于辨识矩阵的属性约简算法得到的约简结果完全相同,但改进算法具有更高的计算效率.     

具有根轨迹渐近特性不变的广义补偿的一种综合算法

本文提出了用动态前馈和线性状态变量反馈(d.f.&l.s.v.f.)使根轨迹渐近特性不变的 一种综合算法.此算法是对Wolovich广义综合算法作内部修正,使所得系统同时具有根轨迹 渐近特性不变性.本文还将此综合算法(内设法)与文献[4]所述的综合算法(外设法)进行了 比较,得出了由这两种综合算法补偿所得的系统阶次相等时的充分必要条件.     

关于线性特征系数的几个问题

本文研究了系统具有线性特征系数的条件。在指出文献[1]、[2]错误的同时,提出了系统具有全部线性特征系数的一个充分条件,并且证明了文献[1]的充分条件是这个充分条件的特殊情况。     

有机化合物性质与键极性诱导指数的关系(四)——Hammett常数与键极诱导指数

我们在文献[1-5]中阐述了键极性诱导指数(PIIB)的概念、计算方法及其与有机化合物性质的密切关系.本文按文献[1]的计算方法和计算机程序,分别计算了各种基团与甲基、氢、苯相连接的键的PIIB,以及基团取代苯后的间位和对位的氢碳键PIIB值,试图与Hammett常数进行比较,研究它们之间的相互关系.计算结果参见表1.     

二部图的所有极大匹配

二部图作为一种非常重要的数据结构有很多特殊性质,针对文献[4]中的二部图的所有极大匹配求解算法,给出了反例证明了该算法是错误的,同时证明了二部图的所有极大匹配的求解是NP难问题.     

连续状态模糊控制系统的鲁棒稳定性分析

1　引言关于模糊系统的稳定性研究 ,目前已有许多相关的分析和设计方法 [1 ] .比如 ,文献 [2 ]中证明了凡用经典控制能稳定控制的系统必可用模糊控制达到相同的稳定性能 ,文献 [3]中有关 Takagi- Sugeno模糊系统的稳定性研究 ,文献 [4 ]中有关关系模型的模糊稳定性分析 ,文献 [     

两种模糊密度确定方法的实验比较

信息融合方法是减少决策不确定性的有效途径和热点问题.本文研究模糊积分信息融合方法中的重要问题-模糊密度的确定方法,对其中两种典型的确定方法进行了细致的比较研究.基于公开而有效的13个UCI标准数据集,进行了成员分类器选择实验、不同融合方法比较实验等,并采用了描述分析、秩次分析、探测性显著性分析,最后与文献[4]中最优单分类器、文献[53中Bagging,Boosting and random forests的最优融合结果进行了对比.结果显示,基于可能度的模糊积分方法优于基于可信度的模糊积分方法、优于文献[5]中最优融合结果;基于可信度的模糊积分方法与文献[5]中最优融合结果总体相当,优于简单平均融合方法,也优于文献[4]中最优单分类器.     

关于TSP的计算复杂性

本文研究TSP的计算复杂性,指出了判定型TSP与最优型TSP具有不同的计算复杂性,同时指出了文献[1]-[3]中的一些错误。     

Application of bilinear transformation to root locus plotting

Use of the bilinear transformations = (z + 1)/(z - 1)is suggested as an alternative to the log root locus method for plotting root loci which cannot be accommodated satisfactorily on linear scales. Familiar rules for locus construction are applicable in thezplane.     

Pole migration on real axis†

This paper presents a clear interpretation of the pole migration on the real axis where many root loci starting from different poles lie together or conflict with one another, by introducing the concept of a pair of real roots. Except in the case of a single root locus, the root loci on the real axis appear always as a pair. Just like the complex number, a pair of real roots is expressed in two parts and the whole root loci for both real and complex roots are plotted in the conventional rectangular coordinates as continuous curves, by which the migration of each pole on the real axis is shown very clearly. Three examples are given.     

预测PI控制系统的根轨迹分析

研究预测PI控制器的根轨迹.根据根轨迹的性质,当存在模型失配时,较小的期望闭环时间常数将导致控制器的输出产生振铃现象.可以通过增大期望闭环时间常数来消除振铃现象.此外,通过根轨迹法,推导出存在增益失配时,预测PI控制系统的稳定性判据.根据稳定性判据,当期望闭环时间常数增大时,增益稳定区间随之而增大;当模型时滞增大时,增益稳定区间随之而减小.数值仿真结果验证了上述结论.     

Closed-form root loci for quasi-dipoles with control design applications

A quasi-dipole is defined to be a pole-zero pair embedded in a suitable approximation to a linear phase field. When complex conjugate plant poles occur near the stability boundary, quasi-dipoles often result from controller designs having compensating zeros. Closed-form root loci expressions are developed for quasi-dipoles; these expressions are shown to provide excellent root locus approximations for practical problems.     

Root Locus for Random Reference Tracking in Systems With Saturating Actuators

This paper develops a root locus technique for random reference tracking in systems with saturating actuators. This is accomplished by introducing the notion of S-poles, which are the poles of the quasilinear system obtained by applying the method of stochastic linearization to the original system with saturation. The path traced by the S-poles on the complex plane when the gain of the controller changes from 0 to infin is the S-root locus. We show that the S-root locus is a subset of the standard root locus, which may terminate prematurely in the so-called termination points. A method for calculating these points is presented and a number of other, more subtle, differences between the usual and the S-root loci are described. In addition, the issue of amplitude truncation in terms of the S-root locus is investigated. Finally, an application of the S-root locus to hard disk drive controller design is presented.     

Computing occlusion-free viewpoints

This paper presents methods to compute the locus of all viewpoints from which features on known polyhedral objects can be viewed in their entirety without being occluded by anything in the environment. Convex and concave polyhedra with or without holes and the viewing model of perspective projection are employed in this work. Initially, properties of the occlusion-free and occluded loci of viewpoints are determined. Based on these properties, two methods to construct these loci together with their complexity analysis are presented. In the first method, a boundary representation of the occlusion-free locus is obtained. In the second method, the locus of occluded viewpoints is expressed in terms of a constructive solid geometry representation that consists of a union of component solids. Implementation results and comparison of the two methods are given     

The root-loci of four pole systems†

The paper shows how the general shape of the root–locus of a four polo system is related to the relative positions of its open loop poles. The various forms of the locus are displayed on two maps. One map shows the loci of systems having two or four real open loop poles while the second map deals with the case of two pairs of complex poles. For each general shape of the locus analytical expressions are given for real axis break points, imaginary axis crossings, and maximum gain consistent with closed loop stability.     

Root locus for SISO dead-time systems: A continuation based approach

We present a numerical method to plot the root locus of Single-Input–Single-Output (SISO) dead-time systems with respect to the controller gain or the system delay. We compute the trajectories of characteristic roots of the closed-loop system on a prescribed complex right half-plane. We calculate the starting, branch and boundary crossing roots of root-locus branches inside the region. We compute the root locus of each characteristic root based on a predictor–corrector type continuation method. To avoid the high sensitivity of roots with respect to the locus parameter in the neighborhood of branch points, the continuation method relies on a natural parameterization of the root-locus trajectory in terms of a distance in the (characteristic root, locus parameter)-space. The method is numerically stable for high order SISO dead-time systems.     

Simple pivoting algorithm for root-locus method of linear systems with delay

A simple and efficient method for the computation of root loci is proposed. The method solves characteristic equations by pivoting procedures. The algorithm is simple, and applicable to linear systems with time delay. Some theoretical results are given to validate the algorithm. The efficiency of the method is shown by several numerical examples.     

Characterization of robust root loci of polytopes of polynomials

This paper deals with the robust root locus problem of a polytope of real polynomials. First, a simple and efficient algorithm is presented for testing if the value set of a polytopic family of polynomials includes the origin of the complex plane. This zero-inclusion test algorithm is then applied along with a pivoting procedure to construct the smallest set of regions in the complex plane which characterizes the robust root loci of a polytope of polynomials.