共查询到20条相似文献,搜索用时 93 毫秒
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本文构造了一种三次三角样条函数 ,函数的每一段由三个函数值生成 ,具有C3连续性和较好的逼近性 ,可方便地进行插值 .基于同样的方法得出了一种C3连续的三角样条曲线 ,曲线也有较好的逼近性 ,而且具有局部性、保凸性等特性 . 相似文献
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本文讨论了二次样条插值的定解条件,在l_1模意义下给出了一类最佳二次样条插值的概念,以及寻找最佳二次样条插值的定解条件的方法.最后讨论了误差估计问题,并给出了实际算例. 相似文献
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为了使得Catmull-Rom型样条兼具形状可调性与高阶连续性,提出了一类带参数的拟CatmullRom样条函数.该样条函数不仅无需求解方程系统即可自动达到C~3连续,而且还可通过所带的2个参数对插值曲线的形状进行调整·通过确定所带参数的最优取值,可获得最佳拟Catmull-Rom样条插值函数. 相似文献
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一种四次有理插值样条及其逼近性质 总被引:3,自引:0,他引:3
1引言有理样条函数是多项式样条函数的一种自然推广,但由于有理样条空间的复杂性,所以有关它的研究成果不象多项式样条那样完美,许多问题还值得进一步的研究.近几十年来,有理插值样条,特别是有理三次有理插值样条,由于它们在曲线曲面设计中的应用,已有许多学者进行了深入研究,取得了一系列的成果(见[1]-[7]).但四次有理插值样条由于其构造所花费的计算量太大以及在使用上很不方便而让人们忽视了其重要的应用价值,因此很少有人研究他们.实际上,在某些情况下四次有理插值样条有其独特的应用效果,如文[8]建立的一种具有局部插值性质的分母为二次的四次有理样条,即一个剖分 相似文献
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C~k连续的保形分段2k次多项式插值 总被引:4,自引:0,他引:4
1.引言在每个子区间上,通过插入至多一个内结点,Brodlie和Butt[1]给出了分段三次多项式保形插值算法,Randal[2]等讨论了分段五次多项式插值,作者[31讨论了一般分段奇次多项式的保形插值,并且给1了内结点的位置范围公式.这种插值方法完全解决了一般的分段奇次多项式的保形插值问题.关于分段偶次多项式的保形插值,大多数文献只讨论分段二次保形插值,这里要特别指出的是Shumake[4j导出了二次样条保凸的充要条件,并且给出了一个二次样条保形插值的方法.在每一个子区间上至多插入一个内结点,则一个二次插值样条就可得到.作… 相似文献
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利用α-样条函数插值及其优化 总被引:1,自引:0,他引:1
首先给出了α-样条函数的概念,并给出了α-样条函数的性质,然后讨论了利用α-样条函数进行插值的问题,得到了α-样条插值函数的存在唯一性定理;并给出了误差分析及收敛性,在此基础上还给出了最优α-样条插值函数的存在性定理与数值求法及例子。 相似文献
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A. Tayebi E. Peyghan 《Journal of Contemporary Mathematical Analysis (Armenian Academy of Sciences)》2012,47(2):70-77
We study a class of Finsler metrics whose Douglas curvature is constant along any Finslerian geodesics. This class of Finsler
metrics is a subclass of the class of generalized Douglas-Weyl metrics and contains the class of Douglas metrics as a special
case. We find a condition under which this class of Finsler metrics reduces to the class of Landsberg metrics. Then we show
this class of metrics contains the class of R-quadratic metrics. 相似文献
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Anuj Dawar Kees Doets Steven Lindell Scott Weinstein 《Mathematical Logic Quarterly》1998,44(3):349-353
This note investigates the class of finite initial segments of the cumulative hierarchy of pure sets. We show that this class is first-order definable over the class of finite directed graphs and that this class admits a first-order definable global linear order. We apply this last result to show that FO(<, BIT) = FO(BIT). 相似文献
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研究非齐次Toda晶格,即一类非齐次非线性微分差分方程的对称与可积性。给出了这一类方程的Lie点对称,条件对称和精确解。给出这类方程与Toda晶格之间的可逆点变换,从而表明这一类方程是可积的。 相似文献
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《Journal of Graph Theory》2018,87(3):317-332
We describe the missing class of the hierarchy of mixed unit interval graphs. This class is generated by the intersection graphs of families of unit intervals that are allowed to be closed, open, and left‐closed‐right‐open. (By symmetry, considering closed, open, and right‐closed‐left‐open unit intervals generates the same class.) We show that this class lies strictly between unit interval graphs and mixed unit interval graphs. We give a complete characterization of this new class, as well as quadratic‐time algorithms that recognize graphs from this class and produce a corresponding interval representation if one exists. We also show that the algorithm from Shuchat et al. [8] directly extends to provide a quadratic‐time algorithm to recognize the class of mixed unit interval graphs. 相似文献
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In this paper we present a new optimization problem and a general class of objective functions for this problem. We show that optimal solutions to this problem with these objective functions are found with a simple greedy algorithm. Special cases include matroids, Huffman's data compression problem, a special class of greedoids, a special class of min cost max flow problems (related to Monge sequences), a special class of weighted f-factor problems, and some new problems. 相似文献
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《Applied Mathematical Modelling》1999,23(4):279-288
The aim of this paper is to select from the large family of possible general linear methods, just a single class which has considerable potential for efficient implementation. This class has possible applications depending on stiff nature of a problem to be performed. A special class of second derivative multistep method (SDMM) is derived. The stability analysis of this class which is depending on free parameters is discussed. The stability regions are plotted for certain choices of parameters. A good comparison between the results of this class and the results due to Gear and Enright is recommended during some numerical tests. 相似文献
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The classification of the fully invariant subgroups of a reduced Abelian p-group is a difficult long-standing problem when one moves outside of the class of fully transitive groups. In this work we
restrict attention to the socles of fully invariant subgroups and introduce a new class of groups which we term socle-regular groups; this class is shown to be large and strictly contains the class of fully transitive groups. The basic properties of such
groups are investigated but it is shown that the classification of even this simplified class of groups, seems extremely difficult.
Received: 4 September 2008 相似文献
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张诚坚 《高等学校计算数学学报》1997,19(1):70-76
1 引言 对于多值多导数方法,由于其多值多导的结构特点有利于提高解的精度,以及其包容性大,它包含了当今常用的多种常微数值方法,诸如:线性多步法,单支方法,多步多导方法,多(单)步Runge—Kutta方法,多导Runge-Kutta方法以及混合方法等.因此收敛性与稳定性的研究具有重要的实践意义和广泛的理论指导意义,也正因如此,这方面的研究工作引起了众多数值工作者们的兴趣,近年来,多值多导法求解刚性问题的B—收敛及其非线性稳定性的研究工作巳获得较大进展,其相应成果可参见文献[1—3],在文献[4,5]中笔者则针对Banach空间中一类非刚性问题-K~((p))类问题,分别探讨了多步多导法及单支方法的收敛性 相似文献