平面三次H-Bézier曲线的形状分析

本文对平面三次H-Bézier曲线的形状进行分析,讨论其诸如奇点、拐点、局部凸和全局凸的几何特征,得出曲线上含有奇点、拐点和曲线为局部凸或全局凸的用控制多边形边向量相对位置表示的充分必要条件.     

Generating Random Points (or Vectors) Controlling the Percentage of them that Are Extreme in their Convex (or Positive) Hull

This paper presents a technique to generate random data in dimensional space m such that their convex (or positive) hull contains a specific percentage of extreme points (or vectors), determined by the analyst or generator of the data. The methodology strives to remove symmetry, regularity, or predictability, which may be desirable in data used to test or compare algorithms or heuristics. There are numerous applications for this methodology.Mathematics Subject Classifications (2000) 65C10, 52B11, 52B55.     

A survey of deterministic models for the EOQ and EPQ with partial backordering

Models for the basic deterministic EOQ or EPQ problem with partial backordering or backlogging make all the assumptions of the classic EOQ or EPQ model with full backordering except that only a fraction of the demand during the stockout period is backordered. In this survey we review deterministic models that have been developed over the past 40 years that address the basic models and extensions that add other considerations, such as pricing, perishable or deteriorating inventory, time-varying or stock-dependent demand, quantity discounts, or multiple-warehouses.     

集合H上矩阵A的左(右)逆、伪左(右)逆

以集合 S与空集Φ的交、并运算为背景 ,定义集合 H ={ 0 ,1 }中的加法与乘法运算 0 ,并考虑 H上一个 s×n级矩阵的左逆矩阵、右逆矩阵以及伪左逆矩阵、伪右逆矩阵的定义 ,并且证明了矩阵 A有左、右逆矩阵 ,A有伪左、右逆矩阵的充分必要条件 .     

带壁生灭过程的定性理论

研究带壁生灭过程(BDP)的定性理论.按照壁0的分类,边界点Z的分类,BDP是否诚实,是否满足向后或向前方程组,存在许多组合类型的BDP.对于每一种类型的BDP,或者没有,或者仅一个,或者有无穷多个.列出了一个详细的表.     

Laura Skew Group Algebras

We prove that if A is an artin algebra, G is a finite group acting on A such that |G| is invertible in A, and R = A[G]^b is a basic algebra associated with the skew group algebra, then A is left supported (or right supported, or laura, or left glued, or right glued, or weakly shod, or shod) if and only if so is R.     

The invariance of elementary symmetric functions

The general problem considered is: what linear transformations on matrices preserve certain prescribed invariants or other properties of the matrices? Specifically, the forms of the following linear transformations are determined: the linear transformations that hold either the trace or the second elementary symmetric function of the eigenvalues of each matrix fixed, and in addition preserve either the determinant, or the permanent, or an elementary symmetric function of the squares of the singular values, or the property of being a rank 1 matrix or a unitary matrix.     

局部可数集族、局部有限集族与Alexandroff问题

本文引进分层强ｓ－映射和分层强紧映射建立具有σ－局部可数网、具有σ－局部可数ｋ－网、具有σ－局部可数基的正则空间以及σ－空间、－空间、ｇ－可度量空间和确定的度量空间之间的联系．这些都是对Ａｌｅｘａｎｄｒｏｆｆ问题的回答．     

Square-free perfect graphs

We prove that square-free perfect graphs are bipartite graphs or line graphs of bipartite graphs or have a 2-join or a star cutset.     

图象的自反与渐近自反

本文对B（X,Y）的自反子空间及渐近自反子空间上的映射（或映射组）,分别给出了一些判别它们的图象（或联合图象）仍为自反及渐近自反的方法。     

Existence of solutions for sub-linear or super-linear operator equations

We investigate solutions to superlinear or sublinear operator equations and obtain some abstract existence results by minimax methods. These results apply to superlinear or sublinear Hamiltonian systems satisfying several boundary value conditions including Sturm-Liouville boundary value conditions and generalized periodic boundary value conditions, and yield some new theorems concerning existence of solutions or nontrivial solutions. In particular, some famous results about periodic solutions to superlinear or sublinear Hamiltonian systems by Rabinowitz or Benci and Rabinowitz are special cases of the theorems.     

DEVELOPABLE SURFACE PATCHES BOUNDED BY NURBS CURVES

In this paper we construct developable surface patches which are bounded by two rational or NURBS curves, though the resulting patch is not a rational or NURBS surface in general. This is accomplished by reparameterizing one of the boundary curves. The reparameterization function is the solution of an algebraic equation. For the relevant case of cubic or cubic spline curves, this equation is quartic at most, quadratic if the curves are Bézier or splines and lie on parallel planes, and hence it may be solved either by standard analytical or numerical methods.     

Radial DEA models without inputs or without outputs

In this paper we consider radial DEA models without inputs (or without outputs), and radial DEA models with a single constant input (or with a single constant output). We demonstrate that (i) a CCR model without inputs (or without outputs) is meaningless; (ii) a CCR model with a single constant input (or with a single constant output) coincides with the corresponding BCC model; (iii) a BCC model with a single constant input (or a single constant output) collapses to a BCC model without inputs (or without outputs); and (iv) all BCC models, including those without inputs (or without outputs), can be condensed to models having one less variable (the radial efficiency score) and one less constraint (the convexity constraint).     

Sharing Nonconvex Costs

The paper analyzes cooperative games with side payments. Each player faces a possibly non-convex optimization problem, interpreted as production planning, constrained by his resources or technology. Coalitions can aggregate (or pool) members' contributions. We discuss instances where such aggregation eliminates or reduces the lack of convexity. Core solutions are computed or approximated via dual programs associated to the grand coalition.     

Conics in Minkowski geometries

Euclidean geometry is the only Minkowski geometry in which either there is a centrally symmetric, or a quadratic conic, or there is a conical ellipsoid or hyperboloid.     

On large sets of resolvable and almost resolvable oriented triple systems

An MTS(v) [or DTS(v)] is said to be resolvable, denoted by RMTS(v) [or RDTS(v)], if its block set can be partitioned into parallel classes. An MTS(v) [or DTS(v)] is said to be almost resolvable, denoted by ARMTS(v) [or ARDTS(v)], if its block set can be partitioned into almost parallel classes. The large set of RMTS(v) [or RDTS(v) or ARMTS(v) or ARDTS(v)] is denoted by LRMTS(v) [or LRDTS(v) or LARMTS(v) or LARDTS(v)]. In this article we do some preliminary study for their existence, and give several recursive theorems using other combinatorial structures. © 1996 John Wiley & Sons, Inc.     

The Maximum Number of Zeros of Functions with Parameters and Application to Differential Equations

In this paper, we first study the problem of finding the maximum number of zeros of functions with parameters and then apply the results obtained to smooth or piecewise smooth planar autonomous systems and scalar periodic equations to study the number of limit cycles or periodic solutions, improving some fundamental results both on the maximum number of limit cycles bifurcating from an elementary focus of order $k$ or a limit cycle of multiplicity $k$, or from a period annulus, and on the maximum number of periodic solutions for scalar periodic smooth or piecewise smooth equations as well.     

平面C-Bézier曲线的奇拐点分析

本文完全地讨论了平面C-曲线和平面C-Bezier曲线的奇拐点和凸性性质:曲线段为且必为下列情形之一:有一各拐点,两个拐点,一个尖点,一个二重结点,处处为凸;并给出了相应的用控制多边形相对位置表示的充分必要条件.     

Generalized Clarke Epiderivatives of Parametric Vector Optimization Problems

This paper deals with the generalized Clarke epiderivative of the extremum (or efficient point) multifunction in parametric vector optimization problems. The formulas for computing and/or estimating the generalized Clarke epiderivative of this extremum multifunction are given in terms of the Clarke tangent cone to the graph of a multifunction or the constraint mapping and/or the Fréchet derivative of the objective function. An application to semi-infinite programming is given.     

A chi-square method for obtaining a priority vector from multiplicative and fuzzy preference relations

Decision makers (DMs)’ preferences on decision alternatives are often characterized by multiplicative or fuzzy preference relations. This paper proposes a chi-square method (CSM) for obtaining a priority vector from multiplicative and fuzzy preference relations. The proposed CSM can be used to obtain a priority vector from either a multiplicative preference relation (i.e. a pairwise comparison matrix) or a fuzzy preference relation or a group of multiplicative preference relations or a group of fuzzy preference relations or their mixtures. Theorems and algorithm about the CSM are developed. Three numerical examples are examined to illustrate the applications of the CSM and its advantages.