几类Lurie型控制系统绝对稳定性充分必要条件

本借助部分变元绝对稳定性的充要条件，得出几类Lurie型控制系统绝对稳定性充分必要条件，这些判据为显式的代数形式，易于验证，也便于在实践中应用。     

Differential structure of the Thompson components of selfadjoint operators

Different equivalence relations are defined in the set of selfadjoint operators of a Hilbert space in order to extend a very well known relation in the cone of positive operators. As in the positive case, for the equivalence class admits a differential structure, which is compatible with a complete metric defined on . This metric coincides with the Thompson metric when is positive.

     

具固定脉冲时刻的脉冲微分系统关于部分变元的指数稳定性

研究了具固定脉冲时刻的脉冲微分系统关于部分变元的指数稳定性,得到了保证零解关于部分变元指数稳定的充分条件,并给出了关于部分变元稳定性的一个新的判定准则.最后给出了其相关例子.     

Multipoint Super-Halley Type Approximation Algorithms in Banach Spaces

We use a new multipoint iteration of at least R-order three to solve a nonlinear operator equation in a Banach space. Under standard Newton-Kantorovich assumptions, we establish two Kantorovich convergence theorems using a new system of recurrence relations. We also give some explicit error bounds for this iteration.     

Unitary part of a contraction

For a contraction A on a Hilbert space H, we define the index j(A) (resp., k(A)) as the smallest nonnegative integer j (resp., k) such that ker(I−Aj∗Aj) (resp., ker(I−Ak*Ak)∩ker(I−AkAk∗)) equals the subspace of H on which the unitary part of A acts. We show that if , then j(A)?n (resp., k(A)?⌈n/2⌉), and the equality holds if and only if A is of class Sn (resp., one of the three conditions is true: (1) A is of class Sn, (2) n is even and A is completely nonunitary with ‖An−2‖=1 and ‖An−1‖<1, and (3) n is even and A=U⊕A^′, where U is unitary on a one-dimensional space and A^′ is of class Sn−1).     

Branched covers along real parts

It is shown that the double cover of a Kähler surface branched along the fixed point set of an anti-holomorphic involution admits a symplectic structure.

     

抽样检查方法中A.B.C三类不合格的确定方法

本文阐明了抽样检查中Ａ．Ｂ．Ｃ三类不合格的确定方法及过程，系ＩＶＥＣＯ汽车零部件国产化所得。     

一类复动力系统的自抗扰控制

复动力系统的对象具有实部和虚部,且实部和虚部之间存在很强的耦合.用结构简单,解耦能力强的自抗扰控制器对一类复动力系统进行仿真研究,分别设计了单入单出控制系统和双入双出控制系统.仿真结果表明,自抗扰控制器可以将复动力系统中的耦合看做扩张状态进行实时估计和补偿,从而具有很好的解耦能力;在系统初始状态和控制器参数一致的情况下,所设计的两种控制系统可达到相同的控制效果.     

克里格法储量计算浅析

克里格法是地质统计学中最主要和最基本的一种局部估计方法.本文围绕计算储量的3大参量,介绍了品位的计算方法,它利用了脉矿的空间变化及其品位的变化特征来计算样品的加权因素和品位、论文据此.改变传统复杂的求体积、体重的计算储量方法,列出了用克里格法计算矿区储量的流程图.