一类对称插值样条和严格凸插值样条

文[1]给出一类C~2连续保凸的插值样条曲线,本文在此基础上进一步讨论(1)当插值多边形为保凸对称时,构造形状对称的C~2连续且保凸的插值样条曲线。(2)当插值多边形严格凸时,构造C~2连续且严格凸的插值样条曲线。     

局部凸空间中Cauchy初值问题解的存在性

首先讨论了局部凸空间中关于非紧性测度的定义及基本性质;然后利用非紧性测度得到了一个新的不动点定理,并运用此定理来讨论局部凸空间中Cauchy初值问题解的局部存在性.     

Are topological relations dependent on the shape of spatial objects?

Topology is normally considered as independent of shape of spatial objects. This may not necessarily be true in describing relations between spatial objects in GIS. In this paper, we present proof that the topological relations between spatial objects are dependent on the shape of spatial objects. That is, that the topological relations of non-convex sets cannot be deformed to the topological relations of convex sets. The significant theoretical value of this paper is on its findings that topology of spatial objects is shape dependent. This indicates that when we want to describe topological relations between spatial objects in GIS, both topology and the shape of objects need to be considered. As a result, spatial data modeling, query and analysis based on the existing understanding of topology of spatial objects may need re-assessed.     

Approximation of NURBS Curves and Surfaces Using Adaptive Equidistant Parameterizations

Introduction Curves and surfaces can be represented using coefficients and a set of basis functions[1]. In the following, only curves are considered, but all statements apply equally to surfaces. Different representations use different sets of basis functions. These basis functions can be, for example, polynomials for polynomial curves, Bernstein-polynomials for Bézier curves, or B-spline basis functions for B-spline curves. As long as the general representation is of the form: 0( ) ( )ni i…     

关于一类集值变分包含解的迭代算法

2002年张石生先生介绍了一类集值变分包含,并在Banach空间内给出了这类集值变分包含解的存在定理和解的迭代算法.在凸度量空间构造一个新的凸结构,对这类集值变分包含定义了带误差的Ishikawa迭代程序,从而得出了这类集值变分包含解的新迭代算法,推广和统一了近期许多人的已知结果.     

An overview on distance and pseudo distance functions and their applications

The fast and accurate collision detection and distance calculation between geometric models is fundamental in robotics, manufacturing and computer-simulated environments. This paper surveys the state of the art in the theory and algorithms of distance and pseudo distance functions between convex sets. An overview on the existing results,including fast algorithms for distance calculation, definitions and properties of various pseudo distance functions (the J-function, the growth distance, and the pseudo minimum translational distance), is presented. The distance and pseudo distance functions are versatile in a wide range of areas.Their applications in robot motion planning, grasp analysis/synthesis, form error evaluation, and engineering optimization is demonstrated.     

Precise evaluation of uniform Doo-Sabin surfaces

Using eigenanalysis of uniform Doo-Sabin subdivision surfaces, parameterization approaches for two types of Doo-Sabin subdivision surfaces are developed, and evaluation methods for values and derivatives of Doo-Sabin surfaces at arbitrary parameters are presented by means of non-iterative approaches. Generalized basis functions for Doo-Sabin surfaces are also derived. Thus, the prejudice is disproved further that subdivision surfaces cannot be evaluated precisely.     

h凸函数的判断准则

文[1]定义了区间上的h凸函数，并给出了它的若干等价命题，文[2]给出了它的若干性质。本文继续文[1，2]的工作，获得h凸函数的若干判别准则。     

局部凸空间的一致光滑性

给出局部凸空间一致光滑的一个充分条件     

一致凸Banach空间有限个非扩张映射的弱收敛

利用1个新的迭代格式研究了Banach空间中有限个非扩张映射的公共不动点问题,并给出了其弱收敛定理,推广了由单个算子所产生的Ishikawa迭代序列的弱收敛性结果.