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 187 毫秒
1.
《Optimization》2012,61(4):993-1009
Conjugate gradient methods are an important class of methods for unconstrained optimization, especially for large-scale problems. Recently, they have been much studied. In this paper, we propose a new two-parameter family of conjugate gradient methods for unconstrained optimization. The two-parameter family of methods not only includes the already existing three practical nonlinear conjugate gradient methods, but has other family of conjugate gradient methods as subfamily. The two-parameter family of methods with the Wolfe line search is shown to ensure the descent property of each search direction. Some general convergence results are also established for the two-parameter family of methods. The numerical results show that this method is efficient for the given test problems. In addition, the methods related to this family are uniformly discussed.  相似文献   

2.
We obtain new sharp embedding theorems for mixed-norm Herz-type analytic spaces in tubular domains over symmetric cones. These results enlarge the list of recent sharp theorems in analytic spaces obtained by Nana and Sehba (2015).  相似文献   

3.
Developing the concept of distributions that are conjugate to a given likelihood function of an unknown parameter in statistical problems of the Bayesian kind, we introduce the notion of locally conjugate distribution families. We investigate some properties of conjugate and locally conjugate families, which are then applied to analytic elimination of the nuisance parameters. The potentialities of this approach are compared with those of the well-known approach related to naturally conjugate distributions. To illustrate the results obtained, we solve a series of known statistical problems. Proceedings of the Seminar on Stability Problems for Stochastic Models. Moscow, Russia, 1996, Part II.  相似文献   

4.
本文讨论了牛曼─贝塞尔级数的共轭级数,建立了其部分和与相应的共轭Fourier三角级数的部分和之间的关系,同时给出了两个收敛定理。  相似文献   

5.
We use the eigenfunction expansion of Green's function of Dirichlet problems to obtain sampling theorems. The analytic properties of the sampled integral transforms as well as the uniform convergence of the sampling series are proved without any restrictions on the integral transforms. We obtain a one- and multi-dimensional versions of sampling theorems. In both cases the sampling series are written in terms of Lagrange-type interpolation expansions. Some examples and the truncation error as well as the stability of the obtained sampling expansions are discussed at the end of the paper. © 1998 B. G. Teubner Stuttgart–John Wiley & Sons Ltd.  相似文献   

6.
SupposeS is a surface of infinite type with pants decomposition ⌆. We construct a real analytic embedding of an infinite-dimensional parameter space into the Fenchel-Nielsen space ofS with respect to ⌆, whose image is made up of topologically conjugate Fuchsian groups for which no two groups in the image are quasiconformally conjugate. Moreover, all of the Fuchsian groups in this parameter space have the same Fenchel—Nielsen twist parameters. As a consequence, arbitrarily close (in the Fenchel-Nielsen topology) to a hyperbolic structure forS there is an infinite-dimensional set of disjoint Teichmüller spaces. Research supported by a University of Oklahoma Junior faculty summer fellowship and in part by NSF Grant DMS-9404174.  相似文献   

7.
以分割区域D为基础将解析函数与共轭解析函数的微分中值定理推广到高阶形式.  相似文献   

8.
In this paper, we investigate linear systems on hyperelliptic varieties. We prove analogues of well-known theorems on abelian varieties, like Lefschetz’s embedding theorem and higher k-jet embedding theorems. Syzygy or \(N_p\) -properties are also deduced for appropriate powers of ample line bundles. This is a first result on linear series, on hyperelliptic varieties.  相似文献   

9.
In this paper we study boundary value problems for semilinear equations involving strongly degenerate elliptic differential operators. Via a Pohozaev??s type identity we show that if the nonlinear term grows faster than some power function then the boundary value problem has no nontrivial solution. Otherwise when the nonlinear term grows slower than the same power function, by establishing embedding theorems for weighted Sobolev spaces associated with the strongly degenerate elliptic equations, then applying the theory of critical values in Banach spaces, we prove that the problem has a nontrivial solution, or even infinite number of solutions provided that the nonlinear term is an odd function.  相似文献   

10.
Sufficient conditions for optimality are derived for partial differential inclusions of parabolic type on the basis of the apparatus of locally conjugate mapping, and duality theorems are proved. The duality theorems proved allow one to conclude that a sufficient condition for an extremum is an extremal relation for the direct and dual problems.   相似文献   

11.
The paper continues the series of papers devoted to surveying and developing methods for solving problems for two-parameter polynomial and rational matrices. Different types of factorizations of two-parameter rational matrices (including irreducible and minimal ones), methods for computing them, and their applications to solving spectral problems are considered. Bibliography: 6 titles.  相似文献   

12.
In this paper atomic decompositions for two-parameter vector-valued martingales are given. With the help of the atomic decompositions the relations between the mutual embedding of two-parameter vector-valued martingale spaces and geometric properties of Banach spaces are investigated. Our study shows that geometric properties of Banach spaces determine the embedding of martingale spaces and conversely the latter can characterize the former. This revised version was published online in June 2006 with corrections to the Cover Date.  相似文献   

13.
Summary In this paper the author has obtained two theorems for the N?rlund summability of Fourier series and its conjugate series respectively under very general conditions.  相似文献   

14.
APPROXIMATION ORDER AND INTERPOLATION SPACES   总被引:1,自引:0,他引:1  
In this paper we introduce the two-parameter operators on Abelian group and establish their interpolation theorems of approximation, which are extensions of the interpolation theorems for nonlinear best approximation by R. Devore and are suitable for the approximation of oprators.  相似文献   

15.
本文把Fourier级数的一些经典结论推广到有理Fourier级数的情况下. 首先给出了有理Fourier级数和共轭有理Fourier级数在有界变差条件下的收敛速度估计. 利用此结论, 得到了类似于Fourier级数的Dirichlet-Jordan定理和W. H. Young定理. 最后, 证明了这两个定理在调和有界变差条件下也成立.  相似文献   

16.
The paper is devoted to general boundary value problems for systems of complex differential and pseudo-differential equations with meromorphic symbols. As the solution spaces, special classes of analytic and exponential functions and functionals are introduced and the existence and uniqueness theorems in these spaces are proved.  相似文献   

17.
We describe, very briefly, the basic ideas and current developments of the homotopy analysis method, an analytic approach to get convergent series solutions of strongly nonlinear problems, which recently attracts interests of more and more researchers. Definitions of some new concepts such as the homotopy-derivative, the convergence-control parameter and so on, are given to redescribe the method more rigorously. Some lemmas and theorems about the homotopy-derivative and the deformation equation are proved. Besides, a few open questions are discussed, and a hypothesis is put forward for future studies.  相似文献   

18.
In the paper it is shown how an embedding of an ordered field F into a formal power series field can be extended canonically to an embedding of any simple extension F(y) of F. Properties of the extended embedding are studied in detail. Several applications are given.  相似文献   

19.
20.
A probabilistic model of a flow of fluid through a random medium,percolation model, provides a typical example of statistical mechanical problems which are easy to describe but difficult to solve. While the percolation problem on undirected planar lattices is exactly solved as a limit of the Potts models, there still has been no exact solution for the directed lattices. The most reliable method to provide good approximations is a numerical estimation using finite power-series expansion data of the infinite formal power series for percolation probability. In order to calculate higher-order terms in power series, Baxter and Guttmann [6] and Jensen and Guttmann [33] proposed an extrapolation procedure based on an assumption that thecorrection terms, which show the difference between the exact infinite power series and approximate finite series, are expressed as linear combinations of the Catalan numbers.In this paper, starting from a brief review on the directed percolation problem and the observation by Baxter, Guttmann, and Jensen, we state some theorems in which we explain the reason why the combinatorial numbers appear in the correction terms of power series. In the proof of our theorems, we show several useful combinatorial identities for the ballot numbers, which become the Catalan numbers in a special case. These identities ensure that a summation of products of the ballot numbers with polynomial coefficients can be expanded using the ballot numbers. There is still a gap between our theorems and the Baxter-Guttmann-Jensen observation, and we also give some conjectures.As a generalization of the percolation problem on a directed planar lattice, we present two topics at the end of this paper: The friendly walker problem and the stochastic cellular automata in higher dimensions. We hope that these two topics as well as the directed percolation problem will be of much interest to researchers of combinatorics.  相似文献   

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