共查询到20条相似文献,搜索用时 93 毫秒
1.
无重复析因试验中位置效应分析的下降方法 总被引:1,自引:1,他引:0
本文介绍了在效应稀疏性的前提下无重复析因试验中位置效应分析的下降Lenth方法,并建立了下降Dong方法,最后对它们作了模拟比较。 相似文献
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本文提出了一种计算共轭梯度法中主要参数βk的新形式,它的计算与目标函数的下降量有关.并且还构造了它的一种杂交形式.利用了βk的新形式及其杂交形式的共轭梯度法都是收敛的.大量的数值实验表明它们是非常有效和稳健的,能用于大规模科学计算. 相似文献
3.
求解无约束优化问题的一类新的下降算法 总被引:2,自引:0,他引:2
本文对求解无约束优化问题提出了一类新的下降算法,并且给出了HS算法与其相结合的两类杂交算法.在Wolfe线搜索下不需给定下降条件,即证明了它们的全局收敛性.数值实验表明新的算法十分有效,尤其是对求解大规模问题而言. 相似文献
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针对遗传算法爬山能力弱但合局搜索能力强的特点 ,本文将遗传算法嵌入到基入传统优化的拟下降算法中 ,并对算法的拟下降步骤做了一定的改进 ,使得整个算法具有全局收敛性 .本文采用马尔可夫的观点进一步证明了算法的全局收敛性 ,并用极难优化的测试函数给出了数值算例 ,证明了本文算法为一种可行的全局优化算法 . 相似文献
5.
根据CG-DESCENT算法[1]的结构和Powell在综述文献[11]中的建议,给出了两种新的求解无约束优化问题的非线性共轭梯度算法. 它们在任意线搜索下都具有充分下降性质, 并在标准Wolfe线搜索下对一般函数能够保证全局收敛性. 通过对CUTEr函数库中部分著名的函数进行试验, 并借助著名的Dolan & Moré[2]评价方法, 展示了新算法的有效性. 相似文献
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濮定国 《应用数学与计算数学学报》1996,10(2):51-56
本文将文[1]提出的一类求总极值方法与非线性规划的下降方法相结合,提出一类带下降方向搜索的求总极值方法,并且证明了这类方法具有线性和超线性收效率. 相似文献
9.
本文讨论了共轭下降法的全局收敛性,对于共轭下降法,建立了两个新的全局收敛性结果,这些结果是文(1)结果的推广。 相似文献
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The aim of this paper is to propose a new multiple subgradient descent bundle method for solving unconstrained convex nonsmooth multiobjective optimization problems. Contrary to many existing multiobjective optimization methods, our method treats the objective functions as they are without employing a scalarization in a classical sense. The main idea of this method is to find descent directions for every objective function separately by utilizing the proximal bundle approach, and then trying to form a common descent direction for every objective function. In addition, we prove that the method is convergent and it finds weakly Pareto optimal solutions. Finally, some numerical experiments are considered. 相似文献
12.
Ezzeddine CHAFAI Maher MNIF 《数学物理学报(B辑英文版)》2014,(4):1212-1224
In [7], Cross showed that the spectrum of a linear relation T on a normed space satisfies the spectral mapping theorem. In this paper, we extend the notion of essential ascent and descent for an operator acting on a vector space to linear relations acting on Banach spaces. We focus to define and study the descent, essential descent, ascent and essential ascent spectrum of a linear relation everywhere defined on a Banach space X. In particular, we show that the corresponding spectrum satisfy the polynomial version of the spectral mapping theorem. 相似文献
13.
In [7], Cross showed that the spectrum of a linear relation T on a normed space satisfies the spectral mapping theorem. In this paper, we extend the notion of essential ascent and descent for an operator acting on a vector space to linear relations acting on Banach spaces. We focus to define and study the descent, essential descent, ascent and essential ascent spectrum of a linear relation everywhere defined on a Banach space X. In particular, we show that the corresponding spectrum satisfy the polynomial version of the spectral mapping theorem. 相似文献
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Manuela Sobral 《Applied Categorical Structures》2001,9(5):505-516
In the category T
op of topological spaces and continuous functions, we prove that surjective maps which are descent morphisms with respect to the class E of continuous bijections are exactly the descent morphisms, providing a new characterization of the latter in terms of subfibrations E(X) of the basic fibration given by T
op/X which are, essentially, complete lattices. Also effective descent morphisms are characterized in terms of effective morphisms with respect to continuous bijections. For classes E satisfying suitable conditions, we show that the class of effective descent morphisms coincides with the one of effective E-descent morphisms. 相似文献
16.
Y. Varshavsky 《Selecta Mathematica, New Series》2002,8(2):283-314
In this paper we recall basic properties of complex Shimura varieties and show that they actually characterize them. This
characterization immediately implies the explicit form of Kazhdan's theorem on the conjugation of Shimura varieties. It also
implies the existence of unique equivariant models over the reflex field of Shimura varieties corresponding to adjoint groups
and the existence of a p-adic uniformization of certain unitary Shimura varieties. In the appendix we give a modern formulation and a proof of Weil's
descent theorem. 相似文献
17.
S. K. Zavriev 《Journal of Global Optimization》1993,3(1):67-78
The paper is devoted to the convergence properties of finite-difference local descent algorithms in global optimization problems with a special -convex structure. It is assumed that the objective function can be closely approximated by some smooth convex function. Stability properties of the perturbed gradient descent and coordinate descent methods are investigated. Basing on this results some global optimization properties of finite-difference local descent algorithms, in particular, coordinate descent method, are discovered. These properties are not inherent in methods using exact gradients.The paper was presented at the II. IIASA-Workshop on Global Optimization, Sopron (Hungary), December 9–14, 1990. 相似文献
18.
本文研究了具有有限升标(降标)的半Fredholm算子,证明了具有有限 升标(降标)的上半Fredholm算子在其摄动类中交换元的摄动下仍具有同样性质,对于下半Fredholm算子有同样结论。从而改进了[1,2]中的主要结果。同时,我们证明了被摄动算子集合扩大(相对于[1]而言)而摄动仍为紧摄动时较[1]中更强的结果。 相似文献
19.
F. Bergeron N. Bergeron R.B. Howlett D.E. Taylor 《Journal of Algebraic Combinatorics》1992,1(1):23-44
The purpose of this paper is twofold. First we aim to unify previous work by the first two authors, A. Garsia, and C. Reutenauer (see [2], [3], [4], [5] and [10]) on the structure of the descent algebras of the Coxeter groups of type A
n and B
n. But we shall also extend these results to the descent algebra of an arbitrary finite Coxeter group W. The descent algebra, introduced by Solomon in [14], is a subalgebra of the group algebra of W. It is closely related to the subring of the Burnside ring B(W) spanned by the permutation representations W/W
J, where the W
J are the parabolic subgroups of W. Specifically, our purpose is to lift a basis of primitive idempotents of the parabolic Burnside algebra to a basis of idempotents of the descent algebra. 相似文献
20.
1. IntroductionA bilevel programming problem (BLPP) involves two sequential optimization problems where the constraint region of the upper one is implicitly determined by the solutionof the lower. It is proved in [1] that even to find an approximate solution of a linearBLPP is strongly NP-hard. A number of algorithms have been proposed to solve BLPPs.Among them, the descent algorithms constitute an important class of algorithms for nonlinear BLPPs. However, it is assumed for almost all… 相似文献