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1.
给出了求以秩为n的m×n阶Loewner矩阵Moore-Penrose逆的快速算法,该算法的计算复杂度为O(mn) O(n2)。  相似文献   

2.
通过构造特殊分块矩阵并研究其三角分解,给出求以秩为n的m×nLoewner型矩阵为系数阵的线性方程组极小范数最小二乘解的快速算法,该算法的计算复杂度为O(mn)+O(n2),而一般方法的计算复杂度为O(mn2)+O(n3).  相似文献   

3.
对时间复杂性为O(n2)的传统直接插入排序,提出了一种多路直接插入排序算法,给出了相关算法描述及性能分析;讨论了新算法中的插入路数与时间复杂性的关系,得出了当路数为O√n时,时间复杂性有最小值O(n3/2)的结论;最后将多路直接插入排序算法与已有的一些直接插入排序算法进行了比较,结果明显优于已有算法.文中的算法思想同样适用于折半插入排序.  相似文献   

4.
列车编组作业中要求将一个任意排列的车列依到站的先后次序重新排列,数学上将其抽象为随机排列的顺序剖分。落表算法是已有的最优算法。本文给出的算法得到与落表算法相同的结果,而对一类随机排列,其时间复杂度低于落表算法。1 落表算法的一些性质 以S(m,n)表示含有几个不同数字,且相邻数字不相同,长为m的所有排列的集合。当m=n时,落表算法的时间复杂度为O(n2)阶。 定理 给定  S(n,n) 随机等可能地取自S(n,n).随机变量X表示求P ()所需要的比较次数,则EX=O(n2),VarX=O(n3). 证明 取 为顺序排列,并且记P(X=k)=P k,当X=k时,若a=1,…  相似文献   

5.
提出一种新的通过一棵严格二叉树的先序序列和这棵严格二叉树的结点的层数构造这棵严格二叉树的非递归算法.举例说明新算法的执行过程.对于有n个结点的严格二叉树,新算法的时间复杂度为O(n),比相应的递归算法的低,新算法的最差情况空间复杂度为O(n),与相应的递归算法的相同.  相似文献   

6.
本文讨论有限群上几个计算问题。我们设了一个O(n~2)时间的算法去查找n阶Abel群的基底(把n阶Abel群分解为循环P群的直积)。给出了复杂度为O(n~2log_2n)的n阶Abel群的检验算法。证明了n阶Abel群的同构检验可在O(nlOg_2n)时间内完成。最后,我们讨论定义在有限群上的旅行售货员问题:证明了该问题是NP完全的,并给出了一个O(m·n~2·2~n)时间的算法求解它。  相似文献   

7.
一种基于数据块交换的快速稳定原地归并算法   总被引:1,自引:0,他引:1  
与其它排序算法相比.二路归并最适合于对2个有序子表进行排序。归并长度分别为m和n的2个 有序子表,经典算法有2种/第一种算法完成归并需要附加O(m+n)的空间,O(m+n)次比较和移动/第 二种算法是原地的.但完成归并需要O(m+n)次比较和O(m*n)次移动,提出了一种基于块交换的快速 稳定原地二路归并算法.实验证明,该算法与以前的原地算法相比,大大降低了元素的移动次数.  相似文献   

8.
通过构造特殊分块矩阵及其三角分解给出了求秩为n 的m×n阶Loewner型矩阵为系数阵的线性方程组极小范数最小二乘解的快速算法, 该算法的计算复杂度为O(mn)+O(n2), 而一般方法的计算复杂度为O(mn2)+O(n3) .  相似文献   

9.
一种基于数据块交换的快速稳定原地归并算法   总被引:2,自引:0,他引:2  
与其它排序算法相比,二路归并最适合于对2个有序子表进行排序。归并长度分别为m和n的2个有序子表,经典算法有2种。第一种算法完成归并需要附加O(m+n)的空间,O(m+n)次比较和移动。第二种算法是原地的,但完成归并需要O(m+n)次比较和O(m×n)次移动。提出了一种基于块交换的快速稳定原地二路归并算法。实验证明,该算法与以前的原地算法相比,大大降低了元素的移动次数。  相似文献   

10.
对于秩为n的m×n阶Cauchy型矩阵C,通过构造特殊分块矩阵并研究其三角分解,进而得到了线性方程组C x=b的极小范数最小二乘解的快速算法,所需运算量为O(m n)+O(n2),而通常构造法方程组的方法所需运算量为O(m n2)+O(n3),用正交化法虽然避免了构造法方程组,但所需的运算量更大些.  相似文献   

11.
Language markedness is a common phenomenon in languages, and is reflected from hearing, vision and sense, i.e. the variation in the three aspects such as phonology, morphology and semantics. This paper focuses on the interpretation of markedness in language use following the three perspectives, i.e. pragmatic interpretation, psychological interpretation and cognitive interpretation, with an aim to define the function of markedness.  相似文献   

12.
理论推导与室内实验相结合,建立了低渗透非均质砂岩油藏启动压力梯度确定方法。首先借助油藏流场与电场相似的原理,推导了非均质砂岩油藏启动压力梯度计算公式。其次基于稳定流实验方法,建立了非均质砂岩油藏启动压力梯度测试方法。结果表明:低渗透非均质砂岩油藏的启动压力梯度确定遵循两个等效原则。平面非均质油藏的启动压力梯度等于各级渗透率段的启动压力梯度关于长度的加权平均;纵向非均质油藏的启动压力梯度等于各渗透率层的启动压力梯度关于渗透率与渗流面积乘积的加权平均。研究成果可用于有效指导低渗透非均质砂岩油藏的合理井距确定,促进该类油藏的高效开发。  相似文献   

13.
As an American modern novelist who were famous in the literary world, Hemingway was not a person who always followed the trend but a sharp observer. At the same time, he was a tragedy maestro, he paid great attention on existence, fate and end-result. The dramatis personae's tragedy of his works was an extreme limit by all means tragedy on the meaning of fearless challenge that failed. The beauty of tragedy was not produced on the destruction of life, but now this kind of value was in the impact activity. They performed for the reader about the tragedy on challenging for the limit and the death.  相似文献   

14.
正The periodicity of the elements and the non-reactivity of the inner-shell electrons are two related principles of chemistry,rooted in the atomic shell structure.Within compounds,Group I elements,for example,invariably assume the+1 oxidation state,and their chemical properties differ completely from those of the p-block elements.These general rules govern our understanding of chemical structures and reactions.Using first principles calcula-  相似文献   

15.
We have developed an adiabatic connection to formulate the ground-state exchange-correlation energy in terms of pairing matrix linear fluctuations.This formulation of the exchange-correlation energy opens a new channel for density functional approximations based on the many-body perturbation theory.We illustrate the potential of such approaches with an approximation based on the particle-particle Random Phase Approximation(pp-RPA).This re-  相似文献   

16.
正The electronic and nuclear(structural/vibrational)response of 1D-3D nanoscale systems to electric fields gives rise to a host of optical,mechanical,spectral,etc.properties that are of high theoretical and applied interest.Due to the computational difficulty of treating such large systems it is convenient to model them as infinite and periodic(at least,in first approximation).The fundamental theoretical/computational problem in doing so is that  相似文献   

17.
For molecular systems,the quantum-mechanical treatment of their responses to static electromagnetic fields usually employs a scalar-potential treatment of the electric field and a vector-potential treatment of the magnetic field.Although the potential for each field separately is associated with the choice of an(unphysical)origin,the precise choice of the origin for the electrostatic field has little consequences for the results.This is different for the  相似文献   

18.
Franck-Condon factors bridge the gap between theoretical modeling and experimental observations for molecular electronic spectroscopy and electron transfer.Under the displaced harmonic oscillator approximation,multidimensional Franck-Condon factors are decomposed into a product of many one-dimensional(1D)Franck-Condon(FC)factors,and each 1D-FC factor is associated with one Huang-Rhys factor that determines the leading contribution of  相似文献   

19.
<正>"The Journal of Shanghai Normal University:Mathematics"is published by Shanghai Normal University as regular issues of The Journal of Shanghai Normal University each year from 2014 in English.The editors-in-chief of the issues are professors Yuhao Cong and Maoan Han.The Journal of Shanghai Normal University was started in 1958 with  相似文献   

20.
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