摘要:

We establish a theorem in the style of Timan-Gopengauz which provides pointwise estimates for the simultaneous approximation of a function and its derivatives in the spaceC[0, ∞), with error measured in an exponentially weighted norm.

ISSN:0163-0563    

DOI:10.1080/01630569208816473

出版商:Marcel Dekker, Inc.    

年代:1992

数据来源: Taylor

摘要:

Thecomplex harmonic spline(C.H.S.) is defined by the formulawhereSM(s) is any complex spline function on the unit circler= ∂U, withMknots and degreen. In this paper, it is proved thatP(z) =f(ø(z)), where ø is a homeomorphism mapping function andfis an analytic function, the number of zeros ofP(z) onUis denoted byN, and we obtain the following result:N= 1/2π ΔrargP(z) <nM

ISSN:0163-0563    

DOI:10.1080/01630569208816474

出版商:Marcel Dekker, Inc.    

年代:1992

数据来源: Taylor

摘要:

For a second order unilateral problem, optimal finite element convergence in energy is proved without assuming any conditions on the coincidence set.

ISSN:0163-0563    

DOI:10.1080/01630569208816475

出版商:Marcel Dekker, Inc.    

年代:1992

数据来源: Taylor

摘要:

The concept of a bounded stochastic integral contractor is utilized to obtain the existence of an optimal stochastic control for a large class of stochastic functional-differential equations with memory. Employing Ito's formula, stochastic global stability in mean [11] is obtained as a by-product. Further, sufficient conditions are given in terms of the Liapunov function for the solution of such nonlinear systems to decay exponentially in mean-square.

ISSN:0163-0563    

DOI:10.1080/01630569208816476

出版商:Marcel Dekker, Inc.    

年代:1992

数据来源: Taylor

摘要:

In this paper we introduce a concept of quasimonotonicity for multifunctions defined on a spaceXwith values inX*, the dual ofX, and give some properties of this class of multifunctions. By using the fact that, for generalized gradients of locally lipschitz functions, quasimonotonicity gives an extremely useful characterization of quasiconvexity, we show some properties of the normal cone to the level set off. We then obtain necessary and sufficient optimality conditions in quasiconvex programming via some variational inequalities.

ISSN:0163-0563    

DOI:10.1080/01630569208816477

出版商:Marcel Dekker, Inc.    

年代:1992

数据来源: Taylor

摘要:

A problem of determining the function of memory from a model of longitudinal wave propagation in an isotropic medium is discussed. The external impulse is assumed to be close to a singular distribution. The problem is approximated by an equation of the second kind and an error estimate is provided. Errors of the method and initial data have a common order in the maximum norms, which implies that the problem is well-posed.

ISSN:0163-0563    

DOI:10.1080/01630569208816478

出版商:Marcel Dekker, Inc.    

年代:1992

数据来源: Taylor

摘要:

The paper studies the linear semi-infinite programming problems and its dual problems. The main purpose is to develop an applicable algorithm to solve such kinds of problems.

ISSN:0163-0563    

DOI:10.1080/01630569208816479

出版商:Marcel Dekker, Inc.    

年代:1992

数据来源: Taylor

摘要:

A new approach to duality in mathematical programming is developed for nonconvex vector problems with set-valued objectives. The approach is based on a weak duality axiom and a separation of nonconvex sets by means of monotonic functions. Strong duality results are obtained without convexity assumptions and without or under a rather weak constraint qualification. An application to nonconvex scalar programming is supplied.

ISSN:0163-0563    

DOI:10.1080/01630569208816480

出版商:Marcel Dekker, Inc.    

年代:1992

数据来源: Taylor

摘要:

Some (C, 1) bounds for orthogonal expansions associated withErdös weightsare established. Roughly speaking, Erdös weights are weights of the formW:=e−Q, whereQis even, continuous and has faster than polynomial growth at infinity. Typical examples areor, and so on. We shall use these bounds together with Bohr-type inequalities, to establishLp, 1 ≤p≤ ∞, Jackson-Favard inequalities.

ISSN:0163-0563    

DOI:10.1080/01630569208816481

出版商:Marcel Dekker, Inc.    

年代:1992

数据来源: Taylor

摘要:

LetXbe a compact HausdorfF space and letD(X) be the set of all continuous real-valued functionsfdefined onXand such that 0 ≤f(x) ≤ 1, for allxεX.The setD(X) is equipped with the uniform topology. We characterize the uniform closure of subsetsA⊂D(X) containing 0 and 1 and ϕψ + (1 − ϕ)η, whenever they contain ϕ, ψ and η

ISSN:0163-0563    

DOI:10.1080/01630569208816482

出版商:Marcel Dekker, Inc.    

年代:1992

数据来源: Taylor