The Exactness Property of the Vector Exact l1 Penalty Function Method in Nondifferentiable Invex Multiobjective Programming

In this article, the vector exact l₁ penalty function method used for solving nonconvex nondifferentiable multiobjective programming problems is analyzed. In this method, the vector penalized optimization problem with the vector exact l₁ penalty function is defined. Conditions are given guaranteeing the equivalence of the sets of (weak) Pareto optimal solutions of the considered nondifferentiable multiobjective programming problem and of the associated vector penalized optimization problem with the vector exact l₁ penalty function. This equivalence is established for nondifferentiable invex vector optimization problems. Some examples of vector optimization problems are presented to illustrate the results established in the article.     

Perturbation of the trigonometric system in L 1(0, π)

In this paper, we study a special perturbation of the function system obtained from the Fejér kernel. It is shown how this relates to the stability of bases and complete systems as well to the stability of the trigonometric system. An approximation algorithm in systems resulting from a perturbation of the original system is given.     

Characterizations of spaces in the unit ball of

Let B denote the unit ball of . For 0<p<∞, the holomorphic function spaces Q_p and Q_p,0 on the unit ball of are defined as

and

In this paper, we give some derivative-free, mixture and oscillation characterizations for Q_p and Q_p,0 spaces in the unit ball of .     

Uniformly non-l n (1) Musielak-Orlicz sequence spaces

We give a necessary and sufficient condition for the uniformly non-l _n ⁽¹⁾ property of Musielak-Orlicz sequence spacesl ^Φ generated by a sequence Φ=(ϕ_n:n⩾l) of finite Orlicz functions such that for eachn∈ℕ. As a result, forn ₀⩾2, there exist spacesl ^Φ which are only uniformly non-l _n ⁽¹⁾ forn⩾n ₀. Moreover we obtain a characterization of uniformly non-l _n ⁽¹⁾ and reflexive Orlicz sequence spaces over a wide class of purely atomic measures and of uniformly non-l _n ⁽¹⁾ Nakano sequence spaces. This extends a result of Luxemburg in [19]. Submitted in memory of Professor W. Orlicz     

Köthe spaces and topological algebra with bases

Nuclear Köthe sequence spaceλ(P) its crossdualλ(P) ^x and their non-nuclear variants are examined as topological algebras. Modelling on them, a general theory of nuclear topological algebras with orthogonal basis is developed. As a by-product, abstract characterizations of sequence algebras ?^∞ andc ₀ are obtained. In a topological algebra set-up, an abstract Grothendieck-Pietsch nuclearity criterion is developed.     

On Smoothing l1 Exact Penalty Function for Constrained Optimization Problems

This article introduces a smoothing technique to the l₁ exact penalty function. An application of the technique yields a twice continuously differentiable penalty function and a smoothed penalty problem. Under some mild conditions, the optimal solution to the smoothed penalty problem becomes an approximate optimal solution to the original constrained optimization problem. Based on the smoothed penalty problem, we propose an algorithm to solve the constrained optimization problem. Every limit point of the sequence generated by the algorithm is an optimal solution. Several numerical examples are presented to illustrate the performance of the proposed algorithm.     

Weakly null sequences in

We construct a weakly null normalized sequence in so that for each , the Haar basis is -equivalent to a block basis of every subsequence of . In particular, the sequence has no unconditionally basic subsequence. This answers a question raised by Bernard Maurey and H. P. Rosenthal in 1977. A similar example is given in an appropriate class of rearrangement invariant function spaces.

     

Benders' decomposition for the constrainedl 1-problem

A constrainedl ₁-problem, involving linear functions only, is considered, and the application of the Benders decomposition method to the solution of the same is discussed. This approach, in principle, seems to be promising and is also applicable to the unconstrained case. Certain small illustrative examples are also presented.This work was done while the first author was visiting the Numerical Optimisation Centre at the Hatfield Polytechnic under the auspices of the British Council and he wishes to acknowledge the excellent research facilities provided by the Polytechnic during the period of his stay. Thanks are also due to Dr. M. C. Bartholomew-Biggs for his valuable comments at various stages of the preparation of this report.     

Conic Formulation for l p -Norm Optimization

In this paper, we formulate the l _p -norm optimization problem as a conic optimization problem, derive its duality properties (weak duality, zero duality gap, and primal attainment) using standard conic duality and show how it can be solved in polynomial time applying the framework of interior-point algorithms based on self-concordant barriers.     

A General Version of Standard Basis and its Application to T-Ideals

A very general version of standard basis is introduced. It covers a wide range of applications using this notion. Particularly, the standard basis of T-ideal in a free associate algebra is presented and a new variant of Spechts problem (concerning PI-algebras) is formulated. A strengthening of the Spechts conjecture is proved for nonmatrix finitely generated algebras. Mathematics Subject Classifications (2000) 16R10, 16Z05.     

Banach空间结构理论的重大进展--关于Gowers-Maurey系列成果

最近,ＧｏｗｅｒｓＷ．Ｔ．和ＭａｕｒｅｙＢ．构造出第一例遗传不可分解空间,否定地解决了无条件基序列问题,由此导致了Ｂａｎａｃｈ空间的结构理论研究中系列问题的解决,本综述介绍这一新动向,反映了Ｇ－Ｍ系列成果,全文分为七个部分,１个历史回顾与问题沿革;２．Ｇ－Ｍ空间ＸＧ１及其遗传不可分解性质,３．关于空间ＸＧ１上的算子构成;４个关于共轭空间ＸＧ１,５．关于Ｇ－Ｍ的系列成果,６．Ｇ－Ｍ型空间构造的     

Controlled dual perturbations for l p -programming

l _p -programming is a common generalization of linear programming, quadratically constrained quadratic programming,l _p -constrainedl _p -approximation, and multiple criteria compromise programming. It is a type of convex programming with objective function and inequality constraints expressed by means ofl _p -norms. The dual program established by Peterson and Ecker is a maximization problem with a concave, upper-semicontinuous objective function over a set of constraints that are essentially linear. In developing a dual method for this problem, we face two major difficulties. One is the non-differentiability of the dual objective function and the other one is an efficient dual-to-primal conversion.In this paper, we introduce a mechanism to construct a suitably perturbed dual program with a differentiable concave objective function over linear constraints. Solving this well-constructed perturbed dual program, we can obtain an-optimal dual solution for an arbitrarily small number. Moreover, we show a way of constructing a linear program based on this dual solution. Then an-optimal primal solution can be obtained by solving the dual of this simple linear program.

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Zusammenfassung Diel _p -Optimierung ist eine Verallgemeinerung, die die lineare Optimierung, quadratische Optimierung mit quadratischen Restriktionen,l _p -Approximation mitl _p -Restriktionen, wie auch Vektoroptimierung umfaßt. Es handelt sich dabei um konvexe Optimierungsaufgaben, bei denen Zielfunktions- und Ungleichungsrestriktionen mittelsl _p -Normen ausgedrückt werden. Das duale Problem nach Peterson and Eckert ist ein Maximierungsproblem mit einer konkaven oberhalb-halbstetigen Zielfunktion über einer Menge von im wesentlichen linearen Restrictionen. Bei der Entwicklung einer dualen Lösungsmethode treten zwei Hauptschwierigkeiten auf: Die eine ist die Nicht-Differenzierbarkeit der dualen Zielfunktion, die andere besteht darin, eine effiziente Übertragung der dualen Lösung in eine primale zu finden.In dieser Arbeit führen wir eine Methode ein, die es gestattet, ein entsprechendes gestörtes duales Programm mit differenzierbarer konkaver Zielfunktion und linearen Restriktion aufzustellen. Bei der Lösung dieses wohl-strukturierten, gestörten dualen Problems erhalten wir eine-optimale Duallösung für beliebig kleines. Ferner zeigen wir einen Weg auf, wie, basierend auf dieser Duallösung, ein lineares Programm formuliert werden kann. Löst man das Dualproblem dieses einfachen linearen Programms, so erhält man eine-optimale Lösung für das Ausgangsproblem.

     

On K0-groups of operator algebras on Banach spaces

This paper merges some classifications of G-M-type Banach spaces simplifically, discusses the condition of K ₀(B(X)) = 0 for operator algebra B(X) on a Banach space X, and obtains a result to improve Laustsen's sufficient condition, gives an example to show that X ≈ X ² is not a sufficient condition of K ₀(B(X)) = 0.     

A Variation of an Extremal Theorem Due to Woodall

We consider a variation of an extremal theorem due to Woodall [12, or 1, Chapter 3] as follows: Determine the smallest even integer (₃C₁,n), such that every n-term graphic sequence = (d₁, d₂,..., d_n) with term sum () = d₁ + d₂ + ... + d_n (₃C₁,n) has a realization G containing a cycle of length r for each r = 3,4,...,l. In this paper, the values of (₃C_l,n) are determined for l = 2m – 1,n 3m – 4 and for l = 2m,n 5m – 7, where m 4.AMS Mathematics subject classification (1991) 05C35Project supported by the National Natural Science Foundation of China (Grant No. 19971086) and the Doctoral Program Foundation of National Education Department of China     

Chevet's theorem for stable processes II

LetB be a separable Banach space and let {:||1} denote the unit ball ofB ^*. LetX be a symmetricp-stableB-valued random variable and let {X _j } _j=1 ⁿ be i.i.d. copies ofX. LetB ₁ be a finite-dimensional Banach space with a symmetric unconditional basis {y _j } _j=1 ⁿ . An upper bound is obtained for that improves the one given by Giné, Marcus and Zinn [J. Functional Anal. 63, 47–73 (1985)].     

On the Energy of a Unit Vector Field

The energy of a unit vector field on a Riemannian manifold M is defined to be the energy of the mapping M T ₁ M, where the unit tangent bundle T ₁ M is equipped with the restriction of the Sasaki metric. The constrained variational problem is studied, where variations are confined to unit vector fields, and the first and second variational formulas are derived. The Hopf vector fields on odd-dimensional spheres are shown to be critical points, which are unstable for M=S ⁵,S ⁷,..., and an estimate on the index is obtained.     

Existence Results for Systems of Vector Equilibrium Problems*

The purpose of this paper is to study systems of vector equilibrium problems. We establish some existence theorems for systems of vector equilibrium problems by using (S)₊-conditions and Kakutani–Fan–Glicksberg fixed point theorem *This work was supported by the Kyungnam University Research Fund 2004     

An algorithm for fitting circular arcs to data using the <Emphasis Type="Italic">l</Emphasis><Subscript><Emphasis Type="Italic">1</Emphasis></Subscript> norm

There are many applications of fitting circular arcs to data. We have for example, system control, using a computer controlled cutting machine, approximating hulls of boats, drawing and image techniques. Out of these applications comes the least squares norm to be the most commonly used criterion. This paper examines how the l ₁ norm is used which seems to be more appropriate than the use of least squares in the context of wild points in the data. An algorithm and different methods to determine the starting points are developed. However, numerical examples are given to help illustrate these methods.      

p-Frames in Separable Banach Spaces

Let X be a separable Banach space with dual X ^*. A countable family of elements {g _i }X ^* is a p-frame (1 p ) if the norm _X is equivalent to the ^p -norm of the sequence {g _i ()}. Without further assumptions, we prove that a p-frame allows every gX ^* to be represented as an unconditionally convergent series g=d _i g _i for coefficients {d _i } ^q , where 1/p+1/q=1. A p-frame {g _i } is not necessarily linear independent, so {g _i } is some kind of overcomplete basis for X ^*. We prove that a q-Riesz basis for X ^* is a p-frame for X and that the associated coefficient functionals {f _i } constitutes a p-Riesz basis allowing us to expand every fX (respectively gX ^*) as f=g _i (f)f _i (respectively g=g(f _i )g _i ). In the general case of a p-frame such expansions are only possible under extra assumptions.     

Moments and Projections of Semistable Probability Measures on p-adic Vector Spaces

In this paper, two topics on semistable probability measures on p-adic vector spaces are studied. One is the existence of absolute moments of operator-semistable probability measures and another is an answer to the question whether one can get semistability of a probability measure from that of all its projections. All results obtained here are extensions of known results for real vector spaces to p-adic vector spaces.