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排序方式: 共有11010条查询结果,搜索用时 31 毫秒
1.
The ergodic theory of Markov chains in random environments   总被引:70,自引:0,他引:70  
Summary A general formulation of the stochastic model for a Markov chain in a random environment is given, including an analysis of the dependence relations between the environmental process and the controlled Markov chain, in particular the problem of feedback. Assuming stationary environments, the ergodic theory of Markov processes is applied to give conditions for the existence of finite invariant measure (equilibrium distributions) and to obtain ergodic theorems, which provide results on convergence of products of random stochastic matrices. Coupling theory is used to obtain results on direct convergence of these products and the structure of the tail -field. State properties including classification and communication properties are discussed.  相似文献
2.
A nonsmooth version of Newton's method   总被引:68,自引:0,他引:68  
Newton's method for solving a nonlinear equation of several variables is extended to a nonsmooth case by using the generalized Jacobian instead of the derivative. This extension includes the B-derivative version of Newton's method as a special case. Convergence theorems are proved under the condition of semismoothness. It is shown that the gradient function of the augmented Lagrangian forC 2-nonlinear programming is semismooth. Thus, the extended Newton's method can be used in the augmented Lagrangian method for solving nonlinear programs.This author's work is supported in part by the Australian Research Council.This author's work is supported in part by the National Science Foundation under grant DDM-8721709.  相似文献
3.
The search for chromatically unique graphs   总被引:64,自引:0,他引:64  
The number of vertex-colourings of a simple graphG in not more than colours is a polynomial in. This polynomial, denoted byP(G, ), is called the chromatic polynomial ofG. A graphG is said to be chromatically unique, in short-unique, ifH G for any graphH withP(H, ) = P(G, ). Since the appearance of the first paper on-unique graphs by Chao and Whitehead in 1978, various families of and several results on such graphs have been obtained successively, especially during the last five years. It is the aim of this expository paper to give a survey on most of the works done on-unique graphs. A number of related problems and conjectures are also included.1980 Mathematical Subject Classification. Primary 05C15This work was done while the author was visiting the Department of Mathematics, National University of Singapore.  相似文献
4.
Quasiregular mappings in even dimensions   总被引:39,自引:0,他引:39  
5.
Hypersurfaces with constant scalar curvature   总被引:38,自引:0,他引:38  
6.
B-vex functions   总被引:37,自引:0,他引:37  
A class of functions, called b-vex functions, is introduced by relaxing the definition of convexity of a function. Both the differentiable and nondifferentiable cases are presented. Members of this class satisfy most of the basic properties of convex functions. This class forms a subset of the sets of both semistrictly quasiconvex as well as quasiconvex functions, but are not necessarily included in the class of preinvex functions.The first author is thankful to the Natural Science and Engineering Research Council of Canada for financial support through Grant A-5319. The authors are also grateful to an anonymous referee for the constructive criticism of the first version of the paper, to Dr. Collen Knickerbocker of St. Lawrence University, and to Mrs. Meena K. Bector for their help in sharpening Examples 2.1 and 2.2, respectively.  相似文献
7.
Isometries of the unit sphere   总被引:35,自引:0,他引:35  
It is shown that isometries between the unit spheres of finite dimensional Banach spaces necessarily map antipodal points to antipodal points.  相似文献
8.
Separative cancellation for projective modules over exchange rings   总被引:27,自引:0,他引:27  
A separative ring is one whose finitely generated projective modules satisfy the propertyAAABBBAB. This condition is shown to provide a key to a number of outstanding cancellation problems for finitely generated projective modules over exchange rings. It is shown that the class of separative exchange rings is very broad, and, notably, closed under extensions of ideals by factor rings. That is, if an exchange ringR has an idealI withI andR/I both separative, thenR is separative. The research of the first and fourth authors was partially supported by a grant from the DGICYT (Spain) and by the Comissionat per Universitats i Recerca de la Generalitat de Catalunya. That of the second author was partially supported by a grant from the NSF (USA). The final version of this paper was prepared while he was visiting the Centre de Recerca Matemàtica, Institut d'Estudis Catalans in Barcelona, and he thanks the CRM for its hospitality.  相似文献
9.
The smoothing Newton method for solving a system of nonsmooth equations , which may arise from the nonlinear complementarity problem, the variational inequality problem or other problems, can be regarded as a variant of the smoothing method. At the th step, the nonsmooth function is approximated by a smooth function , and the derivative of at is used as the Newton iterative matrix. The merits of smoothing methods and smoothing Newton methods are global convergence and convenience in handling. In this paper, we show that the smoothing Newton method is also superlinearly convergent if is semismooth at the solution and satisfies a Jacobian consistency property. We show that most common smooth functions, such as the Gabriel-Moré function, have this property. As an application, we show that for box constrained variational inequalities if the involved function is -uniform, the iteration sequence generated by the smoothing Newton method will converge to the unique solution of the problem globally and superlinearly (quadratically).

  相似文献

10.
Second-order cone programming   总被引:21,自引:0,他引:21  
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