Technical Note Discontinuous Implicit Quasivariational Inequalities in Normed Spaces

In this paper, we consider an implicit quasivariational inequality without continuity assumptions in normed spaces. The main result (Theorem 2.1) provides an infinite-dimensional version of Theorem 3.2 in Ref. 1. To achieve such a goal, we employ Theorem 3.2 in Ref. 1 and the technique of Cubiotti in Ref. 2. In particular, Theorem 3.1 covers a recent result of Cubiotti (Theorem 3.1 of Ref. 2) as a special case. Communicated by F. Giannessi This research was partially supported by the National Science Council of Taiwan, ROC.     

Geometric Condition Measures and Smoothness Condition Measures for Closed Convex Sets and Linear Regularity of Infinitely Many Closed Convex Sets

In this paper, we study geometric condition measures and smoothness condition measures of closed convex sets, bounded linear regularity, and linear regularity. We show that, under certain conditions, the constant for the linear regularity of infinitely many closed convex sets can be characterized by the geometric condition measure of the intersection or by the smoothness condition measure of the intersection. We study also the bounded linear regularity and present some interesting properties of the general linear regularity problem.The author is grateful to the referees for valuable and constructive suggestions. In particular, she thanks a referee for drawing her attention to Corollary 5.14 of Ref. 3, which inspired her to derive Theorem 4.2 and Corollary 4.2 in the revision of this paper.     

关于“华罗庚-王中烈型不等式”一文的注记

指出了［１］的定理２中的一个错误,推广了［１］中定理１给出的华罗庚－王中烈型不等式,避开控制不等式与动态规划模型等专门工具,改用较为初等的平均值不等式证明之,使改正后的［１］中的定理２成其推论     

On the range sets of variational inequalities

This paper investigates the closedness and convexity of the range sets of the variational inequality (VI) problem defined by an affine mappingM and a nonempty closed convex setK. It is proved that the range set is closed ifK is the union of a polyhedron and a compact convex set. Counterexamples are given such that the range set is not closed even ifK is a simple geometrical figure such as a circular cone or a circular cylinder in a three-dimensional space. Several sufficient conditions for closedness and convexity of the range set are presented. Characterization for the convex hull of the range set is established in the case whereK is a cone, while characterization for the closure of the convex hull of the range set is established in general. Finally, some applications to stability of VI problems are derived.This work was supported by the Australian Research Council.We are grateful to Professors M. Seetharama Gowda, Olvi Mangasarian, Jong-Shi Pang, and Steve Robinson for references. We are thankful to Professor Jim Burke for discussions on Theorem 2.1 and Counterexample 3.5.     

广义双拟变分不等式和广义拟变分不等式解的存在性

本文研究一类抽象广义双拟变分不等式和广义拟变分不等式问题，获得了解的存在性定理，改进推广了相关文献的一些主要结果．     

Separate Necessary and Sufficient Conditions for the Local Minimum of a Function

This paper develops two necessary conditions for a local minimum of an arbitrary extended real-valued function (Theorem 2.2) and, quite separately, two conditions, each sufficient for such a function to have a strict local minimum (Theorem 2.3).This work was supported by the National Science Foundation of China, Grant 10171034, and the Natural Science Foundation of the Department of Education of Guangdong Province, Grant 820138.The author thanks the referees for helpful comments.     

Inequalities for hadamard product and unitarily invariant norms of matrices

The paper contains some general theorems for Hadamard product of matrices which in particular include Fiedler's Theorem and a better bound for an inequality on product of eigenvalues of certain matrices due to Ando. Lieb's concavity Theorem has been proved using operator means. Some inequalities for unitarily invariant norms have also been proved.     

Existence of Solutions and an Algorithm for Mixed Variational-Like Inequalities in Banach Spaces

In this paper, we study the class of mixed variational-like inequalities in reflexive Banach spaces. By applying a minimax inequality due to the author, some existence and uniqueness theorems for solutions of mixed variational-like inequalities are proved. Next, by applying the auxiliary problem technique, we suggest an innovative iterative algorithm to compute approximate solutions of the mixed variational-like inequality. Finally, convergence criteria are also discussed. This research was supported by NSF, Sichman Education Department of China, Projects 2003A081 and SZD0406. The author expresses his sincere thanks to Professor H.P. Benson and the anonymous referees for careful comments leading to the present version of this paper.     

On a domination property for vector maximization with respect to cones

We give a corrected version of Theorem 2.1 of Ref. 1.The author is indebted to D. T. Luc, Hungarian Academy of Sciences, Budapest, Hungary, for pointing out his error in the proof of the original version of Theorem 2.1 in Ref. 1.     

覆盖粗糙集模型增值算子及其性质

为了给不断发生变化的数据库的知识发现提供新的数学工具,本文引进覆盖粗糙集模型的确定增值算子ZX(Y)和不确定增值算子ZX(Y),并讨论了它们的有关性质,即通过研究两个新集合hX(x)、lX(x)的性质(定理2.1和定理2.2),给出并证明了两个增值算子的性质(定理2.3和定理2.4)。     

Inequalities for hadamard product and unitarily invariant norms of matrices

The paper contains some general theorems for Hadamard product of matrices which in particular include Fiedler's Theorem and a better bound for an inequality on product of eigenvalues of certain matrices due to Ando. Lieb's concavity Theorem has been proved using operator means. Some inequalities for unitarily invariant norms have also been proved.     

Intégrabilité au sens de Cauchy et -intégrabilité pour des applications à valeurs dans un espace de Banach

The equivalence between the Cauchy left-integrability and the Riemann-integrability, for a bounded function defined on a compact interval of with values in a Banach space, is a particular case of Theorem 2.1. A first generalization to the case of functions defined on a compact rectangle of ² is given by Theorem 2.5.     

A note on preconditional diagonally dominant matrices

This note points out that the main results of [Appl. Math. Comput. 114 (2000) 255] is not true. We show that (1) Theorem 2.1 in [Appl. Math. Comput. 114 (2000) 255] is well known, (2) There are no nonsingular matrices satisfying the sufficient conditions for ensuring diagonally dominance given in Theorem 3.1, and (3) Theorem 4.1 for preconditioning p-cyclic matrices is not true. We also prove that p-cyclic matrices can be column diagonally preconditioned, with a special row permutation if required, to be row diagonally dominant under some assumptions.     

Embeddings in Lattice-O *-Groups

In the paper, the following results are obtained: the existence of simple divisible lattice-O ^*-groups is established (Theorem 2.1) and it is proved that any countable lattice-orderable or right-orderable group can be isomorphically embedded in a simple divisible lattice-O ^*-group (Theorem 2.2 and Corollary 2.3).     

Generalization of an Existence Theorem for Variational Inequalities

By using the concept of exceptional family of elements, Zhao proposed a new existence theorem for variational inequalities over a general nonempty closed convex set (Ref. 1, Theorem 2.3), which is a generalization of the well-known Moré's existence theorem for nonlinear complementarity problems. The proof of Theorem 2.3 in Ref. 1 depends strongly on the condition 0∈K. Since this condition is rather strict for a general variational inequality, Zhao proposed an open question at the end of Ref. 1: Can the condition 0∈K in Theorem 2.3 be removed? In this paper, we answer this open question. Furthermore, we present the new notion of exceptional family of elements and establish a theorem of the alternative, by which we develop two new existence theorems for variational inequalities. Our results generalize the Zhao existence result.     

Comments on Hybrid Conjugate Gradient Algorithm for Unconstrained Optimization

In this note, we aim at improving the proof of Theorem 2.1, 2.2, and Theorem 4.2 in Andrei (J Optim Theory Appl 141:249–264, 2009).     

Categories of abstract smooth models and their singular envelopes

We define the categories of (abstract) smooth models (Definition 1.2) and, in the additive case, their singular envelopes (Definition 1.5). The first main result is a relative version of the Yoneda representation theorem (Theorem 1.6), and the second one is an existence and uniqueness theorem for the singular envelope (Theorem 1.7). In fact we prove the existence of a canonical process which associates with each additive smooth-model categoryS a singular envelopeS-an ofS, whose objects are calledS-analytic spaces (Definition 5.1). We notice that most of the fundamental categories of geometry are of the formS-an (up to equivalence). As an application we introduce here two such categories: Banach differentiable spaces and Banach mixed spaces.The author is indebted to the Department of Mathematics of the University of Rome (La Sapienza) for hospitality and financial support and to the referees for their critical comments on the first version of this paper.     

On some congruence properties of elliptic curves

In this paper, as a consequence of a theorem of Serre on congruence properties of elliptic curves, a complete solution (see Theorem 2.1) is given for an open question (i.e., the KKP question) presented recently by Kim, Koo, and Park. Some partial results for the KKP question of S-type are obtained (see Theorem 3.1 and Corollary 3.2). Several further related questions are also presented and discussed.     

On the solvability of noncoercive linear variational inequalities in separable Hilbert spaces

In this paper, we build an existence theory for linear variational inequalities associated with an operator which generalizes in Hilbert space the class of copositive plus matrices. We show how this theory can be used to study some important engineering problems governed by noncoercive variational inequalities.Thanks are due to Professor V. H. Nguyen for many valuable discussions. The author thanks the Associate Editor and the referees for their helpful suggestions     

A class of iterative methods for solving nonlinear projection equations

A class of globally convergent iterative methods for solving nonlinear projection equations is provided under a continuity condition of the mappingF. WhenF is pseudomonotone, a necessary and sufficient condition on the nonemptiness of the solution set is obtained.The author would like to thank two referees for their useful comments on this paper and one of them, in particular, for bringing Ref. 15 to his attention. The author also thanks Professor He for sending him Ref. 23.