最小度和[a,b]-因子

设α≤b是非负整数，G=(V(G)，E(G))是一个图．G的一个支撑子图F称为G的一个[α,b]-因子，若对任意的v∈V(G)，有α≤dF(v)≤b．本文给出了一个图存在[α,b]-因子的关于最小度的充分条件及存在特殊[α,b]-因子的充分条件，推广了Y.Egawa等人的结果．     

[a,b]-因子包含给定圈的充分条件

设G是一个图且a,b是非负整数,a≤b.图G的一个[a,b]-因子是图G的一个支撑子图H且满足对所有的x∈V(G),a≤dH(x)≤b都成立.给出了图中[a,b]-因子包含给定圈的一个充分条件.     

[a,b]-因子存在性的范-型条件

设G是一个图,a,b是整数且满足0≤a≤b.如果存在G的一个支撑子图F,使对任意的x∈V(G)有a≤d_F(x)≤b,则称F是G的一个[a,b]-因子.本文给出图中具有特定性质的[a,b]-因子的范-型条件.进一步指出这个结果是最好的.     

图的[a,b]-因子存在性的两个结果

设G是一个图,a,b是整数且满足0≤a≤b.如果存在G的一个支撑子图F,使对任意的x∈V(G)有a≤dF(x)≤b,则称F是G的—个[a,b]-因子.本文给出图中具有特定性质的[a,b]-因子的两个充分条件.     

(a,b,C_k)临界图的判定

设G是一个图且a,b是非负整数,a≤b.如果消去G中的任意一个k-圈,剩下的图有[a,b]-因子,则称图G是(a,b,C_k)-临界图.给出了图是(a,b,C_k)-临界图的充分条件.     

2-连通无爪图的连通因子

若图G不含有同构于K1,3的导出子图,则称G为一个无爪图.令a和b是两个整数满足2≤a≤b.本文证明了若G是一个含有[a,b]因子的2连通无爪图,则G有一个连通的[a,b 1]因子.     

一个关于图是[a,b;n]-均匀的度条件

设t,a,b和n为整数且1≤a＜b,t≥3以及n≥1.如果G的导出子图不含有K1,t,则该图G称为K1,t-无爪图.如果对于图G中含有n条边的任意匹配M,都在G中有[a,b]-因子F包含M以及在G中有另一个[a,b]-因子F'不包含M,则图G称为[a,b;n]-均匀图.给出了K1,t-无星图G是[a,b;n]-均匀图的度条件.进一步,指出本文中的结果在某种意义上说是最佳的.     

[a,b]-对等图的范-型条件

既是[a,b]-覆盖又是[a,b]-消去的图称为[a,b]-对等图.设1≤aan+1a+b,则G为[a,b]-对等图.给出了一个图是[a,b]-对等图的关于范-型条件及邻域并的若干充分条件,并指出定理中的条件在一定意义上是最好可能的.     

含有给定k-正则子图的[a,b]-因子

设G是一个图,并设n,k,r,a和b是整数且满足k≥1,k≤a＜b和n≥3.对于G的给定的k-正则图H,如果G是K1,n-free图,且G的最小度至少是((n(a+1)+b-a-(k+1))/(b-k))「(ab+b-a-k)/(2(n-1))」-(n-1)/(b-k)(「(an+b-a-k)/(2(n-1))」)2-1,那么G有一个[a,b]-因子F使得E(H)(∈)E(F).类似地,也得到了关于图G有一个r-因子含有G中给定的k-正则子图的度条件.进一步,指出这些度条件是最佳的.     

图的联结数与[a,b]-因子存在性

设G是一个n阶图,a,b,m1,m2是非负整数且满足1≤a＜b和b≥m1.H1和H2是图G的两个边不交的子图且满足|E(H1)|=m1和|E(H2)|=m2.证明下列结论:若图G的联结数bind(G)＞(a+b-1)(n-1)/bn-(a+b)-2(m1+m2)+2且n≥(b-1)(a+b-1)(a+b-2)+2b(m1+m2)/b(b-1),则图G有一个[a,b]-因子F满足E(H1)(∈)E(F)和E(H2)∩ E(F)=φ.进一步指出这个结果是最好的.     

A REPRESENTATION FORMULA RELATED TO SCHR(O)DINGER OPERATORS

Schr(o)dinger operator is a central subject in the mathematical study of quantum mechanics.Consider the Schrodinger operator H = -△ V on R, where △ = d2/dx2 and the potential function V is real valued. In Fourier analysis, it is well-known that a square integrable function admits an expansion with exponentials as eigenfunctions of -△. A natural conjecture is that an L2 function admits a similar expansion in terms of "eigenfunctions" of H, a perturbation of the Laplacian (see [7], Ch. Ⅺ and the notes), under certain condition on V.     

On a class of self-similar processes with stationary increments in higher order Wiener chaoses

We study a class of self-similar processes with stationary increments belonging to higher order Wiener chaoses which are similar to Hermite processes. We obtain an almost sure wavelet-like expansion of these processes. This allows us to compute the pointwise and local Hölder regularity of sample paths and to analyse their behaviour at infinity. We also provide some results on the Hausdorff dimension of the range and graphs of multidimensional anisotropic self-similar processes with stationary increments defined by multiple Wiener–Itô integrals.     

On a class of Riemann surfaces

It is considered the class of Riemann surfaces with dimT1 = 0, where T1 is a subclass of exact harmonic forms which is one of the factors in the orthogonal decomposition of the spaceΩH of harmonic forms of the surface, namely The surfaces in the class OHD and the class of planar surfaces satisfy dimT1 = 0. A.Pfluger posed the question whether there might exist other surfaces outside those two classes. Here it is shown that in the case of finite genus g, we should look for a surface S with dimT1 = 0 among the surfaces of the form Sg\K , where Sg is a closed surface of genus g and K a compact set of positive harmonic measure with perfect components and very irregular boundary.     

CONTENTS OF VOLUME 30

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Instructions for contributions

正Applied Mathematics-A Journal of Chinese Universities,Series B(Appl.Math.J.Chinese Univ.,Ser.B)is a comprehensive applied mathematics journal jointly sponsored by Zhejiang University,China Society for Industrial and Applied Mathematics,and Springer-Verlag.It is a quarterly journal with     

Journal of Mathematical Research with Applications Guide for Authors

正Journal overview:Journal of Mathematical Research with Applications(JMRA),formerly Journal of Mathematical Research and Exposition(JMRE)created in 1981,one of the transactions of China Society for Industrial and Applied Mathematics,is a home for original research papers of the highest quality in all areas of mathematics with applications.The target audience comprises:pure and applied mathematicians,graduate students in broad fields of sciences and technology,scientists and engineers interested in mathematics.     

Staircase transportation problems with superadditive rewards and cumulative capacities

A cumulative-capacitated transportation problem is studied. The supply nodes and demand nodes are each chains. Shipments from a supply node to a demand node are possible only if the pair lies in a sublattice, or equivalently, in a staircase disjoint union of rectangles, of the product of the two chains. There are (lattice) superadditive upper bounds on the cumulative flows in all leading subrectangles of each rectangle. It is shown that there is a greatest cumulative flow formed by the natural generalization of the South-West Corner Rule that respects cumulative-flow capacities; it has maximum reward when the rewards are (lattice) superadditive; it is integer if the supplies, demands and capacities are integer; and it can be calculated myopically in linear time. The result is specialized to earlier work of Hoeffding (1940), Fréchet (1951), Lorentz (1953), Hoffman (1963) and Barnes and Hoffman (1985). Applications are given to extreme constrained bivariate distributions, optimal distribution with limited one-way product substitution and, generalizing results of Derman and Klein (1958), optimal sales with age-dependent rewards and capacities.To our friend, Philip Wolfe, with admiration and affection, on the occasion of his 65th birthday.Research was supported respectively by the IBM T.J. Watson and IBM Almaden Research Centers and is a minor revision of the IBM Research Report [6].