Almost Fuzzy Compactness in L-fuzzy Top ological Spaces

In this paper, the notion of almost fuzzy compactness is defined in L-fuzzy topological spaces by means of inequality, where L is a completely distributive DeMorgan algebra. Its properties are discusse...     

Tauberian theorems for weak almost convergent functions

The almost convergent function which was introduced by Raimi [6] and discussed by Ho [4], Das and Nanda [2, 3], is the continuous analogue of almost convergent sequences (see [5]). In this paper, we establish the Tauberian conditions and the Cauchy criteria for weak almost convergent functions on R~2+ .     

一致概周期矩阵函数的一些性质

利用纯量概周期函数性质讨论了一致概周期矩阵函数的一些性质.     

Transient solution of anM/M/1 queue with balking

An infinite capacityM/M/1 queue with balking is discussed. Defining the generating function in an unusual and direct way, the time-dependent solution for the system size is obtained elegantly.     

Non-positivity and oscillations of solutions of nonlinear stochastic difference equations with state-dependent noise

Non-positivity and oscillations of nonlinear stochastic difference equations are discussed to characterize the long-term behaviour of their solutions in almost sure sense. Moreover, we present results on non-positivity with probability less than one and give numerous examples satisfying our main hypotheses.     

Weierstrass functions in Zygmund's class

Consider the function

where 1$"> and is an almost periodic function. It is well known that the function lives in the so-called Zygmund class. We prove that is generically nowhere differentiable. This is the case in particular if the elementary condition is satisfied. We also give a sufficient condition on the Fourier coefficients of which ensures that is nowhere differentiable.

     

具广义功能反应函数非自治捕食系统的持久性和概周期问题

针对既有捕食关系,有竞争关系的三种群混合非自治捕食系统,将经典的Holling功能反应函数推广为广义功能反应函数,通过构造Liapunov函数,运用常微分方程定性理论知识,研究了系统的持续性和全局渐近稳定性,并进一步讨论了此系统的正概周期解的存在性和稳定性,得到了系统存在唯一、全局渐近稳定正概周期解的充分条件,对已有的结论进行了较大程度的推广.     

Some properties of Stepanov-like almost automorphic functions and applications to abstract evolution equations

This article is concerned with some properties of Stepanov-like almost automorphic (S ^p -a.a.) functions. We establish a composition theorem about S ^p -a.a. functions, and with its help, study the existence and uniqueness of almost automorphic solutions for semilinear evolution equations in Banach spaces. Moreover, integration and differentiation of S ^p -a.a. functions are discussed. Some theorems extend earlier results.     

L—Fuzzy拓扑空间中的可数F紧性与几乎可数F紧性

本文在Ｌ－ｕｚｚｙ拓扑空间中引入可数Ｆ紧性与几乎可数Ｆ紧性的概念，并讨论了它们的性质及其相互关系。     

赋范空间有界序列收敛的等价性

Two kinds of convergent sequences on the real vector space m of all bounded sequences in a real normed space X were discussed in this paper, and we prove that they are equivalent, which improved the results of [1].     

一类最小相高阶串联系统的几乎干扰解耦问题

讨论了一类最小相高阶串联系统的几乎干扰解耦问题的反馈设计,对一般的由L_2m-L_2mp所定义的非线性增益指标,利用加幂积分器和Back-stepping方法,我们构造性的给出了一种光滑控制律的设计方法,保证闭环系统在内稳定的基础上,使系统达到干扰衰减。     

Solution spaces of homogeneous linear difference systems with coefficient matrices from commutative groups

We analyse the solution spaces of limit periodic homogeneous linear difference systems, where the coefficient matrices of the considered systems are taken from a commutative group which does not need to be bounded. In particular, we study such systems whose fundamental matrices are not asymptotically almost periodic or which have solutions vanishing at infinity. We identify a simple condition on the matrix group which guarantees that the studied systems form a dense subset in the space of all considered systems. The obtained results improve previously known theorems about non-almost periodic and non-asymptotically almost periodic solutions. Note that the elements of the coefficient matrices are taken from an infinite field with an absolute value and that the corresponding almost periodic case is treated as well.     

Networks with small stretch number

In a previous work, the authors introduced the class of graphs with bounded induced distance of order k (BID(k) for short), to model non-reliable interconnection networks. A network modeled as a graph in BID(k) can be characterized as follows: if some nodes have failed, as long as two nodes remain connected, the distance between these nodes in the faulty graph is at most k times the distance in the non-faulty graph. The smallest k such that GBID(k) is called stretch number of G. We show an odd characteristic of the stretch numbers: every rational number greater or equal 2 is a stretch number, but only discrete values are admissible for smaller stretch numbers. Moreover, we give a new characterization of classes BID(2−1/i), i1, based on forbidden induced subgraphs. By using this characterization, we provide a polynomial time recognition algorithm for graphs belonging to these classes, while the general recognition problem is Co-NP-complete.     

一类积分方程的向量值遥远概周期解

讨论了向量值遥远概周期函数空间上一类积分算子的不变性,并应用此结果对一类积分方程的向量值遥远概周期解的存在唯一性进行了研究,得到了其遥远概周期解存在唯一的一个充分性条件.     

随机变量的“几乎确界”与对称性

本文引入随机变量“几乎确界”的概念 ,讨论了有倒对称性的随机变量的性质     

Anti-holomorphic involutions and almost complex structures on four-manifold

Let σ be an anti-holomorphic involution on almost complex manifoldX, the existence of almost complex structure onY=X/σ is discussed. Project supported by the National Natural Science Foundation of China (Grant No. 19771010).     

一类Nevanlinna-Pick问题的Toeplitz向量方法

首次应用改进的Ｔｏｅｐｌｉｔｚ向量方法刻划Ｃａｒａｔｈｅｏｄｏｒｙ函数类中含多重零插值点的Ｎｅｖａｎ ｌｉｎｎａ Ｐｉｃｋ问题与截断的三角矩量问题之间的内在联系，从而给出这类Ｎｅｖａｎｌｉｎｎａ Ｐｉｃｋ问题的可解性准则和通解的参数化表示．     

Pseudo-Complementation on Almost Distributive Lattices

The concept of a pseudo-complementation * on an almost distributive lattice (ADL) with 0 is introduced and it is proved that it is equationally definable. A one-to-one correspondence between the pseudo-complementations on an ADL L with 0 and maximal elements of L is obtained. It is also proved that L* = {a*|a L} is a Boolean algebra which is independent (upto isomorphism) of the pseudo-complementation * on L.AMS Subject Classification (1991): 06D99 06D15     

三维流形上的近余辛$p$-球和近余辛度量双结构

本文主要研究近余辛$p$-球和近余辛度量双结构.首先给出近余辛$p$-球的性质.其次定义了近余辛度量双结构并给出其在三维流形上的相关结论.最后分析当$(1,1)$-型张量$h_1$和$h_2$满足codazzi type 和 cyclic parallel 时具有近余辛度量双结构的三维流形的性质.     

The best quadrature based on given Hermite information for the Sobolev class KW~r[a,b]

As usual, denote by KWr[a,b] the Sobolev class consisting of every function whose (r-1)th derivative is absolutely continuous on the interval [a,b] and rth derivative is bounded by K a.e. in [a, b]. For a function f∈KWr[a, b], its values and derivatives up to r -1 order at a set of nodes x are known. These values are said to be the given Hermite information. This work reports the results on the best quadrature based on the given Hermite information for the class KWr[a. b]. Existence and concrete construction issue of the best quadrature are settled down by a perfect spline interpolation. It turns out that the best quadrature depends on a system of algebraic equations satisfied by a set of free nodes of the interpolation perfect spline. From our another new result, it is shown that the system can be converted in a closed form to two single-variable polynomial equations, each being of degree approximately r/2. As a by-product, the best interpolation formula for the class KWr[a, b] is also obtained.