首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 78 毫秒
1.
基于Chebyshev多项式函数系的齐次扩容精细算法   总被引:1,自引:2,他引:1  
基于Chebyshev多项式函数系的特点,设计了求解非齐次线性自治系统的一种新的精细算法——基于Chebyshev正交多项式系的齐次扩容精细算法(HHPD-C)。这一算法不仅避免了HPD—F算法中的矩阵求逆,还克服了HHPD—F算法中对右端激励的周期性要求,从而适合于任意形式的右端激励;不仅计算量小、设计合理,还易于推广和实现。理论与算倒表明,HHPD—C算法十分有效。  相似文献   

2.
一种基于Taylor级数的齐次扩容精细算法   总被引:7,自引:0,他引:7  
借助齐次扩容技巧及Taylor级数,设计了求解非齐次线性定常系统的一种新的精细算法-基于Taylor级数的齐次扩容精细算法(HHPD-T)。该算法有效地解决了HPD-F算法中涉及矩阵求逆的问题,因而计算量小,同时具有设计合理、易于推广、易于实现等特点。两个典型算例表明,应用HHPD-T求解,数值结果更为理想。  相似文献   

3.
设计出求解时域支集无限型任意激励的非齐次线性自治系统的一种长效精细算法(简称:HHPD—LF),特点是:传递矩阵H属“一次计算,终生使用”,它突破了时域有限的约束,没有矩阵求逆、没有对右端函数的周期性要求,在一定程度上适合于任意形式的右端激励。理论与算例表明HHPD-LF算法十分有效。  相似文献   

4.
基于第二类Chebyshev多项式函数系的特点与齐次扩容技巧,设计了求解非齐次线性自治系统的一种新的长效精细算法(HHPD CS).其不仅避免了HPD F算法中的矩阵求逆,还克服了HH-PD F算法中对右端激励的周期性要求,从而适合于任意形式的右端激励.理论与算例表明,长效HHPD CS算法十分有效,不仅计算量比R K算法小许多,而且数值稳定、计算精度高、设计合理,易于推广和实现.  相似文献   

5.
如何应用精细算法求解非齐次或非线性问题是计算力学中的热点问题,通常采用区间精细算法,但这一方法的精细传递矩阵与t步长的区间有关,计算量很大.能否设计出“一次计算,终生使用”的长效精细算法是一个倍受关注的问题,尤其是针对非线性的情况.以Burgers方程为模型设计出一种能解决二次非线性困难的长效精细算法.这类技巧不难推广至一般的二次非线性PDE(偏微分方程),且有广泛的应用,还建立了相应算法的基础理论与误差分杯两个算例表明,计算结果十分令人满意.  相似文献   

6.
周期时变线性系统的周期精细积分算法   总被引:3,自引:0,他引:3  
周期时变线性系统系数矩阵的时变性与不可交换性是其精细积分算法设计中的瓶颈,应用Peano-Baker级数理论:首先在单周期内获得精细转移矩阵,然后利用周期性简化计算,这不仅有效地提高了全时域上的计算精度,而且还能节省较多计算量.本文设计了2个数值算例,与四阶R—K算法的数值解相比较,结果表明,本文建立的周期时变精细积分算法(PTHPD)有明显的优越性。  相似文献   

7.
通过引进诱导分划的概念及相关技巧,提出了一类特殊时变系统的爬坡精细算法(CHPD)。与R—K方法及传统精细算法(HPD)的比较表明:这一算法计算精度高,大大降低了运算量,理论估计及数值算例都证实了算法的优越性。  相似文献   

8.
本文论述了超精细场连续分布的、带有重叠谱的穆斯堡尔谱拟合和超精细场分布函数的计算机算法,用本算法建立的程序,在PDP—11/23和ND—100型计算机上,成功地进行了拟合和超精细场分布函数计算。  相似文献   

9.
给出了一个新的子算法A,用以计算本文第一部分提出的主算法A中的“一阶方向”.由于此子算法已充分利用了算法A中已有的信息,所以并没有增加计算量.这样,联合算法A及子算法A,就可以得到一个实用的可行优化算法  相似文献   

10.
单纯形的加速算法   总被引:10,自引:0,他引:10  
该文提出了能有效加快收敛速度的修改单纯形算法。在原单纯形算法的基础上增加了一种新的反射方向的计算方法;用“映射单纯形”方法代替“单纯形顶点代换”方法;有选择地采用“单纯形压缩”计算。计算结果表明,修改单纯形算法对初值的适应范围更宽,收敛速度更快,收敛次数从50—100次降低到30次左右,可以避免迭代过程中的单纯形退化现象。  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.
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号