The formulas for the representation of functions of two variables as a difference of sublinear functions

ABSTRACT

Having a function being a difference of sublinear functions defined on a plane, we present a formula for effective calculation of sublinear functions such that their difference is equal to the given one. Moreover, these newly calculated sublinear functions are minimal and as such unique-up-to-linear-summand. We also provide examples of such functions.     

Sublinear Operators with Rough Kernel on Herz Spaces with Variable Exponents

We prove some boundedness results for a large class of sublinear operators with rough kernel on the homogeneous Herz spaces where the three main indices are variable exponents. Some known results are extended.     

次线性算子在加权Herz空间上的弱型估计

给出了一些次线性算子从加权Herz空间到加权弱Herz空间的有界性证明。     

齐型空间的Herz-Morrey空间上的次线性算子的有界性

在齐型空间上定义了Herz-Morrey空间，并研究了某些次线性算子在Herz-Morrey空间上的有界性。     

次线性半正边值问题的正解

本文讨论 Sturm-Liouville边值问题(p(t)u′)′+λf(t,u)=0, r＜t＜R;au(r)-bp(r)u′(r)=0;cu(R)+dp(R)u′(R)=0,正解的存在性,这里允许非线性项取负值．当f在u=+∞处一致次线性增长且无界时，必存在λ^*＞0，对?λ:λ＞λ^*,上述边值问题存在正解．     

一类四阶奇异边值问题的正解存在的充分必要条件

利用上下解方法和极大值原理给出了一般边界条件下四阶微分方程的奇异迫值问题有C^2[0，1]和C^3[0，1]正解存在的充分必要条件．推广了韦忠礼(1999)的结果。     

Solvability results for sublinear functions and operators

In this paper there are stated asymptotic solvability results which yield a Farkas' lemma for sublinear functions and operators. Applications to duality for homogeneous programming and to necessary optimality conditions for nonlinear programming are given. Some closedness conditions used in the paper are also discussed.

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Zusammenfassung In dieser Arbeit werden asymptotische Lösbarkeitsresultate angegeben, die ein Farkas-Lemma für sublineare Funktionen und Operatoren liefern. Es werden Anwendungen auf die Dualitätstheorie homogener Programme und auf notwendige Optimalitätsbedingungen der nichtlinearen Programmierung angegeben. Einige Abgeschlossenheitsvoraussetzungen, die in der Arbeit benutzt werden, werden diskutiert.

     

Approximating average parameters of graphs

Inspired by Feige (36th STOC, 2004), we initiate a study of sublinear randomized algorithms for approximating average parameters of a graph. Specifically, we consider the average degree of a graph and the average distance between pairs of vertices in a graph. Since our focus is on sublinear algorithms, these algorithms access the input graph via queries to an adequate oracle. We consider two types of queries. The first type is standard neighborhood queries (i.e., what is the ith neighbor of vertex v?), whereas the second type are queries regarding the quantities that we need to find the average of (i.e., what is the degree of vertex v? and what is the distance between u and v?, respectively). Loosely speaking, our results indicate a difference between the two problems: For approximating the average degree, the standard neighbor queries suffice and in fact are preferable to degree queries. In contrast, for approximating average distances, the standard neighbor queries are of little help whereas distance queries are crucial. © 2008 Wiley Periodicals, Inc. Random Struct. Alg., 2008     

具有(F,α,ρ,d)—凸的分式规划问题的最优性条件和对偶性

给出了一类非线性分式规划问题的参数形式和非参数形式的最优性条件,在此基础上,构造出了一个参数对偶模型和一个非参数对偶模型,并分别证明了其相应的对偶定理,这些结果是建立在次线性函数和广义凸函数的基础上的.