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1.
本文采用分解、合成的思想,求解非线性等式约束优化问题,第一节,介绍了算法的发展;第二节,利用Fletcher罚函数,给出本文使用的两个算法:通常信赖域算法,非单调信赖域算法。非单调信赖域算法是通常信赖域算法的推广,算法实践表明:非单调信赖域算法更具优越性,开始受到充分重视。  相似文献   

2.
研究一类最大特征值函数与一个仿射映射复合后的函数与一个二次连续可微的凸函数的和的无约束优化问题,许多的实际应用问题的约束优化问题可以转化为这种形式的无约束问题来求解。将处理非光滑问题的UV-分解方法应用于这一类无约束优化问题,先给出目标函数在某一点处的3种形式的UV-空间分解,证明了3种空间分解形式是等价的。其次,给出目标函数的U-Lagrange函数及它的一阶和二阶展开式。最后,基于UV-空间分解理论给出解决这样一类无约束优化问题的UV-分解算法,并证明此算法是超线性收敛的。文章结论为解决最大特征值函数的联合函数的优化问题提供了一种新的途径。  相似文献   

3.
基于小波包变换的自适应多用户检测   总被引:1,自引:0,他引:1  
在分析传统自适应多用户检测的基础上,提出了一种基于小波包变换的自适应多用户检测算法.该算法用小波包变换进行前处理,然后再通过最小均方(LMS)算法实现自适应多用户检测.与通常的自适应多用户检测算法相比,该算法利用了小波包变换对小波空间进行分解,信号经小波包变换后自相关性会下降,收敛速度提高.同时在此分解过程中,根据信号与白噪声小波包变换完全不同的特性进行信号消噪.理论分析和仿真结果表明,该算法与传统LMS自适应多用户检测算法和基于小波变换的自适应多用户检测算法相比,算法收敛速度更快,且计算量较少,易于实时实现,还具有良好性能.同时仿真结果表明该算法收敛速度与小波基和分解级数的选择有关,分解级数越大,收敛速度越快;对于同一小波基系列,小波基正则性越好收敛速度越快。  相似文献   

4.
一种排序Jacobi算法及其并行实现   总被引:1,自引:0,他引:1  
针对角对称矩阵的特征值分解问题,提出了一种新的排序Jacobi算法(S-Jacobi).该算法利用Jacobi旋转中的内角和外角实现了特征值的自动排序.仿真结果表明,S-Jacobi的收敛条件在实际中容易满足,而且其收敛速度优于传统的无特征值排序的Jacobi算法.另外,为S-Jacobi的并行实现提出的旋转度计算电路与传统Jacobi算法的情况相比,只需要少量的额外硬件资源.  相似文献   

5.
为提高非负矩阵分解的收敛速度,在Lee和Seung的倍乘更新算法及改进ILSMU—EUC算法的基础上,通过调整运算顺序,限制不必要的更新方法,提出加速IILSMU-EUC算法。IILSMU-EUC算法是从计算量和内部迭代分析中,对运算耗费量大的矩阵提出限制更新方法,即调整计算顺序,按步骤顺序执行,能够减少计算量及不必要的上百万次的更新。实验结果表明:与原倍乘更新MU算法、梯度映射算法和分层交替最小二乘算法比较,IILSMU-EUC算法误差小、快速收敛性强、提取特征明显,从而验证了改进算法的有效性、稳定性和高效性。  相似文献   

6.
邓自立 《科学技术与工程》2005,5(20):1473-14781484
可逆的向量滑动平均(MA)模型参数估计问题本质上是一个矩阵谱分解问题。基于向量MA模型和状态空间模型之间的变换,用Kalman滤波方法证明了矩阵谱分解的Gevers-Wouters算法的一致性和指数收敛性,且证明了收敛速度由MA多项式矩阵的行列式的零点决定。当这些零点不接近单位圆周时,Gevers-Wouters算法可高精度、快速地给出MA参数估计,因而提供一种快速有效的谱分解工具。  相似文献   

7.
对于椭圆边界问题,基于自然边界归化方法,提出了一种新的重叠型区域分解算法,得到了一个控制收敛速度定理。  相似文献   

8.
提出了求解一般二次规划问题的一种分解迭代算法.算法的主要思想是对问题的Hessian矩阵G进行正则分裂,即G=N H并且满足N-H是正定的.在每次迭代中用一个易于求解的矩阵N代替G进行计算.在矩阵G是正定的条件下,算法具有线性收敛性质,产生的迭代点列收敛到原问题的最优解.当矩阵G不正定时,算法产生的点列收敛到问题的稳定点.  相似文献   

9.
通过将多项式简单地分解为正负两个部分,提出了求解多项式最大正极和最小正根的迭代算法,在此基础上,利用因式分解定理得到了其所有正根的计算方法,证明了它的收敛性,并估计了收敛速度。在确保收敛的情况下,本文又引入一个辅助函数对两种方法进行了修正,修正后的算法使得计算量大为减少,而其收敛速度却没有受到影响。  相似文献   

10.
基于对时称矩阵的Bunch-Parlett分解,将信赖域子问题转换成一个等价的信赖域子问题,构造出一种易于实现的梯度路径,然后沿着这条路径用非单调的信赖域法来找出问题的大约最优解,该法对海色矩阵无正定的限制,保留了信赖域方法的特色,并证明了这种算法的全局收敛性和二阶收敛速率。  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.
何延凌 《科技信息》2008,(4):258-258
Language is a means of verbal communication. People use language to communicate with each other. In the society, no two speakers are exactly alike in the way of speaking. Some differences are due to age, gender, statue and personality. Above all, gender is one of the obvious reasons. The writer of this paper tries to describe the features of women's language from these perspectives: pronunciation, intonation, diction, subjects, grammar and discourse. From the discussion of the features of women's language, more attention should be paid to language use in social context. What's more, the linguistic phenomena in a speaking community can be understood more thoroughly.  相似文献   

13.
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   

14.
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   

15.
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   

16.
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   

17.
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   

18.
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   

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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