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1.
约束最优化问题的距离函数算法及其收敛性   总被引:3,自引:1,他引:2  
约束最优化问题是实际中经常遇到的,应用非常广泛的一类问题。本文对P.Huard 在[1]中提出的中心算法作了进一步的探讨,指出:要提高中心算法的收敛速度,关键是选取合适的距离函数。为此,本文重新构造了距离函数,并对不同的距离函数,进行了实例计算与比较。另外,本文也论述了选取合适的距离函数,能使原来的约束优化问题用无约束方法计算,则程序简单、计算方便、运算时间省。最后,还讨论了算法的收敛性问题。  相似文献   

2.
本文讨论了一类非凸稳态大系统的递阶优化方法,采用增加部分约束罚项的思想,提出一种既能保持原问题的可分性结构,又能将原问题凸化的构造增广拉格朗日函数的新方法,证明了凸化后的新问题与原问题之间的等价性关系,研究了它们的递阶优化算法,证明了所给算法的局部收敛性,讨论了算法所具有的收敛速度。  相似文献   

3.
给出约束最优化问题的一个强适定性定义.并给出了最优化问题是强适定性的一个充分性条件是适定性的最优化问题的约束更具有局部误差界.讨论了它与一类罚函数方法的收敛性关系.  相似文献   

4.
讨论一般随机二阶锥互补约束问题的求解算法.为处理模型中的不确定性,算法采用样本平均近似(SAA)抽样技术.不同于之前的工作,设计了一般光滑化SAA算法框架,可以在满足要求的一类光滑化函数中根据需要进行选择,从而构造光滑化SAA算法,并保证收敛性.具体的,若SOCMPCC线性无关约束规范等条件成立,则算法构造子问题的稳定点和最优解分别以概率1收敛到原问题的C稳定点和最优解.最后具体给出两个光滑化函数与其对应光滑化SAA算法的例子,由一般光滑化算法框架可得这两种算法收敛.  相似文献   

5.
将服务选择问题建模为带QoS约束的非线性最优化问题,并提出了一种参数自适应的改进遗传算法(IPAGA).构造了基于双曲正切函数的非线性参数变换函数,当迭代次数或种群多样性程度增加时,使遗传算法的交叉和变异概率相应地非线性递减,以保证算法的全局收敛性和收敛速度.实验结果表明:算法能够快速搜索出全局近似最优解,具有很高的有效性和可行性.  相似文献   

6.
本文讨论带一般约束的可分非凸稳态大系统的凸化方法。采用只增加部分约束罚项的思想,提出了一种既能将原非凸问题目标函数凸化,又能保持原问题可分性的构造增广Lagrange函数的新方法,并给出了该问题的递阶优化算法,证明了算法的收敛性,给出了收敛速度的估计.  相似文献   

7.
在[1]中的基础上,通过一系列的构造,而将无约束最优化问题中的记忆梯度方法直接推广到了求解带有线性约束的非线性规划问题中,并且在两种不同的线搜索之下,证明了推广的算法具有整体收敛性质。  相似文献   

8.
有文献给出了一般等式约束非线性最优化问题的一种求解途径。在此基础上将线性等式约束非线性最优化问题转化为非线性最小二乘问题求解,提出了求解最优化问题的一种新思路。然后利用Gauss-Newton法求解非线性最小二乘问题,在求解过程中引入非精确的一维搜索,提高了计算的效率,加快了算法收敛的速度,从而找到了具有线性等式约束非线性最优化问题的一个新算法,算法具有很好的收敛性,收敛速度是二阶的。最后经过数值实验证明新算法与Matlab优化工具箱计算的结果一致,是可行的、有效的。  相似文献   

9.
用改进的光滑NCP函数替代了文[1,2]中的弱互补函数,提出了一种新的光滑牛顿法,从而实现了一般约束优化问题的KKT条件到非线性方程组之间的完全等价转化,且将文[3]中提出的求解无约束最优化问题的修正BFGS方法加以改进,应用于求解一般的约束最优化问题,避免了计算Hesse矩阵工作量较大的问题,并在一定的条件下证明了该算法的全局收敛性.  相似文献   

10.
有文献给出了一般等式约束非线性最优化问题的一种求解途径。在此基础上将线性等式约束非线性最优化问题转化为非线性最小二乘问题求解,提出了求解最优化问题的一种新思路。然后利用Gauss-Newton法求解非线性最小二乘问题,在求解过程中引入非精确的一维搜索,提高了计算的效率,加快了算法收敛的速度,从而找到了具有线性等式约束非线性最优化问题的一个新算法,算法具有很好的收敛性,收敛速度是二阶的。最后经过数值实验证明新算法与Matlab优化工具箱计算的结果一致,是可行的、有效的。
  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.
The discovery of the prolific Ordovician Red River reservoirs in 1995 in southeastern Saskatchewan was the catalyst for extensive exploration activity which resulted in the discovery of more than 15 new Red River pools. The best yields of Red River production to date have been from dolomite reservoirs. Understanding the processes of dolomitization is, therefore, crucial for the prediction of the connectivity, spatial distribution and heterogeneity of dolomite reservoirs.The Red River reservoirs in the Midale area consist of 3~4 thin dolomitized zones, with a total thickness of about 20 m, which occur at the top of the Yeoman Formation. Two types of replacement dolomite were recognized in the Red River reservoir: dolomitized burrow infills and dolomitized host matrix. The spatial distribution of dolomite suggests that burrowing organisms played an important role in facilitating the fluid flow in the backfilled sediments. This resulted in penecontemporaneous dolomitization of burrow infills by normal seawater. The dolomite in the host matrix is interpreted as having occurred at shallow burial by evaporitic seawater during precipitation of Lake Almar anhydrite that immediately overlies the Yeoman Formation. However, the low δ18O values of dolomited burrow infills (-5.9‰~ -7.8‰, PDB) and matrix dolomites (-6.6‰~ -8.1‰, avg. -7.4‰ PDB) compared to the estimated values for the late Ordovician marine dolomite could be attributed to modification and alteration of dolomite at higher temperatures during deeper burial, which could also be responsible for its 87Sr/86Sr ratios (0.7084~0.7088) that are higher than suggested for the late Ordovician seawaters (0.7078~0.7080). The trace amounts of saddle dolomite cement in the Red River carbonates are probably related to "cannibalization" of earlier replacement dolomite during the chemical compaction.  相似文献   

14.
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   

15.
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   

16.
AcomputergeneratorforrandomlylayeredstructuresYUJia shun1,2,HEZhen hua2(1.TheInstituteofGeologicalandNuclearSciences,NewZealand;2.StateKeyLaboratoryofOilandGasReservoirGeologyandExploitation,ChengduUniversityofTechnology,China)Abstract:Analgorithmisintrod…  相似文献   

17.
There are numerous geometric objects stored in the spatial databases. An importance function in a spatial database is that users can browse the geometric objects as a map efficiently. Thus the spatial database should display the geometric objects users concern about swiftly onto the display window. This process includes two operations:retrieve data from database and then draw them onto screen. Accordingly, to improve the efficiency, we should try to reduce time of both retrieving object and displaying them. The former can be achieved with the aid of spatial index such as R-tree, the latter require to simplify the objects. Simplification means that objects are shown with sufficient but not with unnecessary detail which depend on the scale of browse. So the major problem is how to retrieve data at different detail level efficiently. This paper introduces the implementation of a multi-scale index in the spatial database SISP (Spatial Information Shared Platform) which is generalized from R-tree. The difference between the generalization and the R-tree lies on two facets: One is that every node and geometric object in the generalization is assigned with a importance value which denote the importance of them, and every vertex in the objects are assigned with a importance value,too. The importance value can be use to decide which data should be retrieve from disk in a query. The other difference is that geometric objects in the generalization are divided into one or more sub-blocks, and vertexes are total ordered by their importance value. With the help of the generalized R-tree, one can easily retrieve data at different detail levels.Some experiments are performed on real-life data to evaluate the performance of solutions that separately use normal spatial index and multi-scale spatial index. The results show that the solution using multi-scale index in SISP is satisfying.  相似文献   

18.
In the 19th century the society was controlled by men, and women were just appendants of them, they had not any rights and freedom. But Jane was an exception, she showed some characteristics of early feminist. Jane showed her characteristics of feminism in three aspects: rebellion, equality, and independence. These characteristics were helpful to her success, and feminism is the only way out for women of that time.  相似文献   

19.
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   

20.
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   

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