Convex Approximation of Some Kind of Convex Functions

Suppose that f(x)∈C~2[0,1] is a convex function.we concern the approxi-mation degree of f(x)by convex algebraic Polynomials.Among the other things,it is a very important question whether we have convex polynomials of degree nsuch that     

Very Convex Banach Spaces

ＶｅｒｙＣｏｎｖｅｘＢａｎａｃｈＳｐａｃｅｓＴｅｇｕｓｉ（特古斯）Ｓｕｙａｌａｔｕ（苏雅拉图）（ＤｅｐａｒｔｍｅｎｔｏｆＭａｔｈｅｍａｔｉｃｓ，ＩｎｎｅｒＭｏｎｇｏｌｉａＮｏｒｍａｌＵｎｉｖｅｒｓｉｔｙ，Ｈｕｈｈｏｔ，０１００２２）ＬｉＹｏｎｇｊｉｎ...     

Equicontinuous Seton Locally Convex Spaces

Ｌｅｔ（Ｅ，γ）ｂｅａｌｏｃａｌｌｙｃｏｎｖｅｘｓｐａｃｅａｎｄＥ′ｉｔｓｃｏｎｊｕｇａｔｅｓｐａｃｅ．ＡＥ′ｂｅａｎｅｑｕｉｃｏｎｔｉｎｕ－ｏｕｓｓｅｔｏｎ（Ｅ，γ）．ＴｈｅｗｅｌｌｋｎｏｗｎＡｌａｏｇｌｕ－ＢｏｕｒｂａｋｉＴｈｅｏｒｅｍ（［１］Ｐ２４８）ｓｔａｔｅｓｔｈａｔｅａｃｈｅ－ｑｕｉｃｏｎｔｉｎｕｏｕｓｓｅｔｏｎ（Ｅ，γ）ｉｓσ（Ｅ′，Ｅ）ｒｅｌａｔｉｖｅｌｙｃｏｍｐａｃｔｓｕｂｓｅｔ．Ｎｅｖｅｒｔｈｅｌｅｓｓ，ｅｑｕｉｃｏｎｔｉｎｕｏｕｓｓｅｔｉｓσ（Ｅ′，Ｅ）ｒｅｌａｔｉｖｅｌ…     

Meromorphic Convex Functions with Negative Coefficients

Let σ_k(a) be the class of functions f(f)=1/z-sur from n=1 to ∞(|a_n|z~n), regular in the punctured disk E={z:0<|z|<1} and satisfying Re(1 zf"(z)/f'(z))<-a (0≤a<1) for z∈E. In this paper we obtain coefficient inequalities, distortion and closure Theorems for the class σ_k(a). Further we obtain the class preserving integral operator of the form     

Approximation of Convex Bodies by ConvexBodies

For the affine distance d(C,D) between two convex bodies C, D(?) Rn, which reduces to the Banach-Mazur distance for symmetric convex bodies, the bounds of d(C, D) have been studied for many years. Some well known estimates for the upper-bounds are as follows: F. John proved d(C, D) < n1/2 if one is an ellipsoid and another is symmetric, d(C, D) < n if both are symmetric, and from F. John's result and d(C1,C2) < d(C1,C3)d(C2,C3) one has d(C,D) < n2 for general convex bodies; M. Lassak proved d(C, D) < (2n - 1) if one of them is symmetric. In this paper we get an estimate which includes all the results above as special cases and refines some of them in terms of measures of asymmetry for convex bodies.     

Duality of Unary Convex Functions Programming

Most nonliner programming problems consist of functions which are sums of unary,convexfunctions of linear fuctions.In this paper.we derive the duality forms of the unary oonvex optimization,and these technuqucs are applied to the geometric programming and minimum discrimination informationproblems.     

γ-Active Constraints in Convex Semi-Infinite Programming

In this article, we extend the definition of γ-active constraints for linear semi-infinite programming to a definition applicable to convex semi-infinite programming, by two approaches. The first approach entails the use of the subdifferentials of the convex constraints at a point, while the second approach is based on the linearization of the convex inequality system by means of the convex conjugates of the defining functions. By both these methods, we manage to extend the results on γ-active constraints from the linear case to the convex case.     

Aperture-Angle and Hausdorff-Approximation of Convex Figures

The aperture angle α(x,Q) of a point x ∉ Q in the plane with respect to a convex polygon Q is the angle of the smallest cone with apex x that contains Q. The aperture angle approximation error of a compact convex set C in the plane with respect to an inscribed convex polygon Q⊂C is the minimum aperture angle of any x∈C∖Q with respect to Q. We show that for any compact convex set C in the plane and any k>2, there is an inscribed convex k-gon Q⊂C with aperture angle approximation error . This bound is optimal, and settles a conjecture by Fekete from the early 1990s. The same proof technique can be used to prove a conjecture by Brass: If a polygon P admits no approximation by a sub-k-gon (the convex hull of k vertices of P) with Hausdorff distance σ, but all subpolygons of P (the convex hull of some vertices of P) admit such an approximation, then P is a (k+1)-gon. This implies the following result: For any k>2 and any convex polygon P of perimeter at most 1 there is a sub-k-gon Q of P such that the Hausdorff-distance of P and Q is at most  . This research was supported by the Korea Research Foundation Grant funded by the Korean Government (MOEHRD) (KRF-2006-311-D00763). NICTA is funded through the Australian Government’s Backing Australia’s Ability initiative, in part through the Australian Research Council.     

A Characterization of a p Uniformly Convex Space

V.I.Istrtescu introduces the following notions:A Banach space E is said to be p-uniformly convex (p≥2)if the modulus of convexity of E satisfies the inequality for some positive constant C.A Banach space E is said to be q-uniformly smooth (1相似文献   

Contraction Flow by Certain Curvature of Convex Hypersurfaces

In the following mixed tensors on the hypersurface M Rn+1 under consideration willbe denoted by T={ Tijkl} ,the induced metric by g={ gij} and the second fundamentalform by A={ hij} .We always sum overrepeated indices from1 to n and use brackets forthe inner product on M:〈Tijk,Sijk〉 =gisgjαgkβTijk Ssαβ,　 | T| 2 =〈Tijk,Tijk〉.Setrkl =gkαhαl,Sm(λ1 ,… ,λn) = i1<… 相似文献   

关于“Programming with Semilocally Convex Function”

“Ｐｒｏｇｒａｍｍｉｎｇ ｗｉｔｈ Ｓｅｍｉｌｏｃａｌｌｙ Ｃｏｎｖｅｘ Ｆｕｎｃｔｉｏｎ”一文对定义在中星形集上的局部凸函数给出了二择一定理，并应用到约束最小化问题，得到了优化条件和共轭定理，本文用具体反例说明这些结果是错误的。     

Weakly Unconditional Cauchy Series on Locally Convex Spaces

Ｗｅａｋｌｙ　Ｕｎｃｏｎｄｉｔｉｏｎａｌ　Ｃａｕｃｈｙ　Ｓｅｒｉｅｓ　ｏｎ　Ｌｏｃａｌｌｙ　Ｃｏｎｖｅｘ　ＳｐａｃｅｓＬｉＲｏｎｇｌｕ（李容录）（ＤｅｐａｒｔｍｅｎｔｏｆＭａｔｈｅｍａｔｉｃｓ，ＨａｒｂｉｎＩｎｓｔｉｔｕｔｅｏｆＴｅｃｈｎｏｌｏｇｙ，...     

Optimization,Convex and Variational Analysis – Volume II

Set-Valued and Variational Analysis -     

Star Unfolding Convex Polyhedra via Quasigeodesic Loops

We extend the notion of star unfolding to be based on a quasigeodesic loop Q rather than on a point. This gives a new general method to unfold the surface of any convex polyhedron ℘ to a simple (nonoverlapping) planar polygon: cut along one shortest path from each vertex of ℘ to Q, and cut all but one segment of Q.     

Maximizing Strictly Convex Quadratic Functions with Bounded Perturbations

The problem of maximizing [(f)\tilde]=f+p\tilde{f}=f+p over some convex subset D of the n-dimensional Euclidean space is investigated, where f is a strictly convex quadratic function and p is assumed to be bounded by some s∈[0,+∞[. The location of global maximal solutions of [(f)\tilde]\tilde{f} on D is derived from the roughly generalized convexity of [(f)\tilde]\tilde{f}. The distance between global (or local) maximal solutions of [(f)\tilde]\tilde{f} on D and global (or local, respectively) maximal solutions of f on D is estimated. As consequence, the set of global (or local) maximal solutions of [(f)\tilde]\tilde{f} on D is upper (or lower, respectively) semicontinuous when the upper bound s tends to zero.     

Locally Farkas–Minkowski Systems in Convex Semi-Infinite Programming

A pair of constraint qualifications in convex semi-infinite programming, namely the locally Farkas–Minkowski constraint qualification and generalized Slater constraint qualification, are studied in the paper. We analyze the relationship between them, as well as the behavior of the so-called active and sup-active mappings, accounting for the tightness of the constraint system at each point of the variables space. The generalized Slater constraint qualification guarantees a regular behavior of the supremum function (defined as supremum of the infinitely many functions involved in the constraint system), giving rise to the well-known Valadier formula.     

The Projection onto a Direct Product of Convex Cones

ＴｈｅＰｒｏｊｅｃｔｉｏｎｏｎｔｏａＤｉｒｅｃｔｒｏｄｕｃｔｏｆＣｏｎｖｅｘＣｏｎｅｓＬｉｕＷｅｉ（刘维）ａｎｄＳｈｉＮｉｎｇｚｈｏｎｇ（史宁中）（ＤｅｐａｒｔｍｅｎｔｏｆＭａｔｈｅｍａｔｉｃｓ，ＮｏｒｔｈｅａｓｔＮｏｒｍａｌＵｎｉｖｅｒｓｉｔｙ，Ｃ...     

Maximal Points of Convex Sets in Locally Convex Topological Vector Spaces: Generalization of the Arrow–Barankin–Blackwell Theorem

In 1953, Arrow, Barankin, and Blackwell proved that, if C is a nonempty compact convex set in Rⁿ with its standard ordering, then the set of points in C maximizing strictly positive linear functionals is dense in the set of maximal points of C. In this paper, we present a generalization of this result. We show that that, if C is a compact convex set in a locally convex topological space X and if K is an ordering cone on X such that the quasi-interiors of K and the dual cone K* are nonempty, then the set of points in C maximizing strictly positive linear functionals is dense in the set of maximal points of C. For example, our work shows that, under the appropriate conditions, the density results hold in the spaces Rⁿ, L^p(, ), 1p, l^p, 1p, and C (), a compact Hausdorff space, when they are partially ordered with their natural ordering cones.     

Fixed Points of Cone Maps in Locally Convex Spaces

Guo [1] gives some fixed point theorems of cone maps in Banacb space. Here we generalize the main resnlts of [1] to a locally convex space. We remark that the approach in [1] is not applicable in our paper. Throughout this paper. X is a Hausdorff locally convex topological vector space over the field of real numbers, K is a closed convex subset     

Generalized Knaster–Kuratowski–Mazurkiewicz Theorem Without Convex Hull

In this paper, a new notion of Knaster–Kuratowski–Mazurkiewicz mapping is introduced and a generalized Knaster–Kuratowski–Mazurkiewicz theorem is proved. As applications, some existence theorems of solutions for (vector) Ky Fan minimax inequality, Ky Fan section theorem, variational relation problems, n-person noncooperative game, and n-person noncooperative multiobjective game are obtained.