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LOG-CONCAVITY OF THE FIRST DIRICHLET EIGENFUNCTION OF SOME ELLIPTIC DIFFERENTIAL OPERATORS AND CONVEXITY INEQUALITIES FOR THE RELEVANT EIGENVALUE
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作者 Andrea COLESANTI 《Acta Mathematica Scientia》 2025年第1期143-152,共10页
Given an open bounded subset Ω of ℝ^(n) we consider the eigenvalue problem{Δu-(■u,■V)=-λvu,u>0inΩ,u=0 onδΩ,where V is a given function defined inΩandλV is the relevant eigenvalue.We determine sufficient c... Given an open bounded subset Ω of ℝ^(n) we consider the eigenvalue problem{Δu-(■u,■V)=-λvu,u>0inΩ,u=0 onδΩ,where V is a given function defined inΩandλV is the relevant eigenvalue.We determine sufficient conditions on V such that ifΩis convex,the solution u is log-concave.We also determine sufficient conditions ensuring that λ_(V),as a function of the setΩ,verifies a convexity inequality with respect to the Minkowski addition of sets. 展开更多
关键词 EIGENVALUE LOG-CONCAVITY elliptic operator Brunn-Minkowski inequality convex body
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CONVEXITY OF THE FREE BOUNDARY FOR AN AXISYMMETRIC INCOMPRESSIBLE IMPINGING JET
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作者 王晓慧 《Acta Mathematica Scientia》 SCIE CSCD 2024年第1期234-246,共13页
This paper is devoted to the study of the shape of the free boundary for a threedimensional axisymmetric incompressible impinging jet.To be more precise,we will show that the free boundary is convex to the fluid,provi... This paper is devoted to the study of the shape of the free boundary for a threedimensional axisymmetric incompressible impinging jet.To be more precise,we will show that the free boundary is convex to the fluid,provided that the uneven ground is concave to the fluid. 展开更多
关键词 Euler system axisymmetric impinging jet INCOMPRESSIBLE free boundary convexity
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Several Problems about the Generalized Convexity 被引量:1
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作者 王治国 《Chinese Quarterly Journal of Mathematics》 CSCD 2000年第3期100-102,共3页
In this article,we will prove that,under the differential condition,the strict pseudo_convexity and Orgega_Rheinbold pseudo_convex are equivalent.What's more,we will discuss the relation between the r_convexity an... In this article,we will prove that,under the differential condition,the strict pseudo_convexity and Orgega_Rheinbold pseudo_convex are equivalent.What's more,we will discuss the relation between the r_convexity and the analog convexity. 展开更多
关键词 pseudo_convexity EQUIVALENCE r_convexity analog convexity
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Second Note on the Definition of S<sub>1</sub>-Convexity
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作者 I. M. R. Pinheiro 《Advances in Pure Mathematics》 2015年第3期127-130,共4页
In this note, we discuss the definition of the S1-convexity Phenomenon. We first make use of some results we have attained for?? in the past, such as those contained in [1], to refine the definition of the phenomenon.... In this note, we discuss the definition of the S1-convexity Phenomenon. We first make use of some results we have attained for?? in the past, such as those contained in [1], to refine the definition of the phenomenon. We then observe that easy counter-examples to the claim extends K0 are found. Finally, we make use of one theorem from [2] and a new theorem that appears to be a supplement to that one to infer that? does not properly extend K0 in both its original and its revised version. 展开更多
关键词 Analysis convexity DEFINITION s-convexity Geometry Shape S-convexity s-Convex FUNCTION S-Convex FUNCTION
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Necessary and Sufficient Conditions in Smooth Programming with Generalized Convexity 被引量:1
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作者 孙清滢 叶留青 《Chinese Quarterly Journal of Mathematics》 CSCD 2000年第4期33-37,共5页
Hanson and Mond have grven sets of necessary and sufficient conditions for optimality in constrained optimization by introducing classes of generalized functions, called type Ⅰ functions. Recently, Bector definded un... Hanson and Mond have grven sets of necessary and sufficient conditions for optimality in constrained optimization by introducing classes of generalized functions, called type Ⅰ functions. Recently, Bector definded univex functions, a new class of functions that unifies several concepts of generalized convexity. In this paper, additional conditions are attached to the Kuhn Tucker conditions giving a set of conditions which are both necessary and sufficient for optimality in constrained optimization, under appropriate constraint qualifications. 展开更多
关键词 necessary and sufficient conditions generalized convexity nonlinear programming multiobjective programming type functions
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Differentiability of Functions on Spheres and Criterions of Convexity
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作者 CHEN Tingting GUO Qi 《Wuhan University Journal of Natural Sciences》 CAS CSCD 2022年第4期273-280,共8页
Some basic concepts for functions defined on subsets of the unit sphere,such as the s-directional derivative,s-gradient and s-Gateaux and s-Frechet differentiability etc,are introduced and investigated.These concepts ... Some basic concepts for functions defined on subsets of the unit sphere,such as the s-directional derivative,s-gradient and s-Gateaux and s-Frechet differentiability etc,are introduced and investigated.These concepts are different from the usual ones for functions defined on subsets of Euclidean spaces,however,the results obtained here are very similar.Then,as applications,we provide some criterions of s-convexity for functions defined on unit spheres which are improvements or refinements of some known results. 展开更多
关键词 spherical convexity spherically convex function Gateaux and Frechet differentiability criterion of convexity
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Minima Domain Intervals and the S-Convexity, as well as the Convexity, Phenomenon
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作者 I. M. R. Pinheiro 《Advances in Pure Mathematics》 2012年第6期457-458,共2页
In this paper, we propose a refinement in the analytical definition of the s2-convex classes of functions aiming to progress further in the direction of including s2-convexity properly in the body of Real Analysis.
关键词 Analysis convexity Definition S-convexity
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First Note on the Definition of s<i>1</i>-Convexity
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作者 I. M. R. Pinheiro 《Advances in Pure Mathematics》 2014年第12期674-679,共6页
In this note, we analyze a few major claims about . As a consequence, we rewrite a major theorem, nullify its proof and one remark of importance, and offer a valid proof for it. The most important gift of this paper i... In this note, we analyze a few major claims about . As a consequence, we rewrite a major theorem, nullify its proof and one remark of importance, and offer a valid proof for it. The most important gift of this paper is probably the reasoning involved in all: We observe that a constant, namely t, has been changed into a variable, and we then tell why such a move could not have been made, we observe the discrepancy between the claimed domain and the actual domain of a supposed function that is created and we then explain why such a function could not, or should not, have been created, along with others. 展开更多
关键词 Analysis convexity DEFINITION S-convexity GEOMETRY
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MONOTONICITY,CONVEXITY AND INEQUALITIES INVOLVING THE GENERALIZED ELLIPTIC INTEGRALS 被引量:5
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作者 Miaokun WANG Wen ZHANG Yuming CHU 《Acta Mathematica Scientia》 SCIE CSCD 2019年第5期1440-1450,共11页
We establish the monotonicity and convexity properties for several special functions involving the generalized elliptic integrals, and present some new analytic inequalities.
关键词 Gaussian HYPERGEOMETRIC function generalized ELLIPTIC INTEGRALS convexity inequality
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NORMAL STRUCTURE AND SOME GEOMETRIC PARAMETERS RELATED TO THE MODULUS OF U-CONVEXITY IN BANACH SPACES 被引量:2
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作者 Ji Gao Satit Saejung 《Acta Mathematica Scientia》 SCIE CSCD 2011年第3期1035-1040,共6页
We present a short and simple proof of the recent result of Yang and Wang [12]. Stimulated by their idea, two geometric parameters Uax(ε) and βx (ε), both related to Gao's modulus of U-convexity of a Banach sp... We present a short and simple proof of the recent result of Yang and Wang [12]. Stimulated by their idea, two geometric parameters Uax(ε) and βx (ε), both related to Gao's modulus of U-convexity of a Banach space X, are introduced. Their properties and the relationships with normal structure are studied. Some existing results involving normal structure and fixed points for non-expansive mappings in Banach spaces are improved. 展开更多
关键词 uniform normal structure modulus of convexity ULTRAPOWER
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APPROXIMATE CONVEXITY AND CONCAVITY OFGENERALIZED GROTZSCH RING FUNCTION 被引量:2
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作者 王根娣 裘松良 +1 位作者 张孝惠 褚玉明 《Applied Mathematics(A Journal of Chinese Universities)》 SCIE CSCD 2006年第2期203-206,共4页
In this paper, the so-called approximate convexity and concavity properties of generalized Groetzsch ring function μa (r) by studying the monotonieity,convexity or concavity of certain composites of μa(r) are ob... In this paper, the so-called approximate convexity and concavity properties of generalized Groetzsch ring function μa (r) by studying the monotonieity,convexity or concavity of certain composites of μa(r) are obtained. 展开更多
关键词 generalized Grotzsch ring function Ramanujan's modular equation convexity concawty.
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基于Convexity模型的航空公司利率风险管理
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作者 金永利 《中国民航学院学报》 2005年第5期1-6,共6页
国际性特征日趋明显的中国航空公司正面临着金融市场上的诸多不确定性,其中利率风险日益凸显。将Convexity模型这一在西方发达国家较为成熟的风险管理工具引入中国,并将其应用到中国航空公司的风险管理实践,对利率风险进行了极为精确的... 国际性特征日趋明显的中国航空公司正面临着金融市场上的诸多不确定性,其中利率风险日益凸显。将Convexity模型这一在西方发达国家较为成熟的风险管理工具引入中国,并将其应用到中国航空公司的风险管理实践,对利率风险进行了极为精确的量化评估,最后给出了相应的规避方法。 展开更多
关键词 风险管理 利率风险评估 convexity模型 航空公司
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THE MODULUS OF CONVEXITY AND THE EQUIVALENT CONDITIONS OF UNIFORMLY NON-SQUARE SPACES
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作者 韩瑞珠 《Journal of Southeast University(English Edition)》 EI CAS 1989年第1期15-20,共6页
This paper shows that X is uniformly non-square iff P(η_o)】0 for someη_o∈(0,2).Thus X is super-reflexive if and only if for X there exists an equivalent normwhich meets the above condition.By virtue of the before ... This paper shows that X is uniformly non-square iff P(η_o)】0 for someη_o∈(0,2).Thus X is super-reflexive if and only if for X there exists an equivalent normwhich meets the above condition.By virtue of the before mentioned result,the author derives the necessary,and suffi-cient conditions for X and l^p(X_j)being uniformly non-square,respectively,and gives acharacterization of finite-dimensional spaces which are uniformly non-square. 展开更多
关键词 MODULUS convexity/uniformly non-square SPACE super-reflexive SPACE
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Characterization of Uniform PL-convexity of Complex Banach Space by Functions with Two Variables
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作者 HUANG Hai jun,LIU Pei de (College of Mathematics and Computer Science, Wuhan University, Wuhan 430072,China) 《Wuhan University Journal of Natural Sciences》 EI CAS 1999年第4期399-403,共5页
We give a new characterization ofq-uniform PL-convexity of complex Banach space by using the existence of a kind of functions with two variables and then prove a sharp weak (1, 1)-type inequality for analytic martinga... We give a new characterization ofq-uniform PL-convexity of complex Banach space by using the existence of a kind of functions with two variables and then prove a sharp weak (1, 1)-type inequality for analytic martingales with values in the Banach space. 展开更多
关键词 analytic martingale uniform PL convexity mean square operator
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Convexity and Positivity of Bivariate Quadratic Bézier Surfaces over a Rectangle
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作者 DING You dong School of Computer Engineering and Science, Shanghai University, Shanghai 200072, China 《Journal of Shanghai University(English Edition)》 CAS 2001年第1期20-28,共9页
With the help of several discriminants about the zero points of a quartic polynomial, the sufficient and necessary conditions for the positivity and nonnegativity of the quartic polynomial over an interval I(-∞,+... With the help of several discriminants about the zero points of a quartic polynomial, the sufficient and necessary conditions for the positivity and nonnegativity of the quartic polynomial over an interval I(-∞,+∞) was derived. Based on these conclusions, the sufficient and necessary conditions for the positivity and convexity of the 2×2 Bézier surface over a rectangle were obtained. A simple sufficient condition was deduced also and finally several examples were given. 展开更多
关键词 Bézier surface convexity POSITIVITY DISCRIMINANT
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Optimality Conditions for Static Programming with Generalized Convexity
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作者 刘建林 《Journal of Shanghai Jiaotong university(Science)》 EI 2005年第3期314-317,共4页
The definitions of generalized pseudoconvex,generalized quasiconvex and its stri ctly generalized convexity were presented for the static programming at locally star -shaped set using the concept of right-upper deriva... The definitions of generalized pseudoconvex,generalized quasiconvex and its stri ctly generalized convexity were presented for the static programming at locally star -shaped set using the concept of right-upper derivative and the concept of sub linear. The sufficient and necessary conditions of the static programming were d erived in terms of a generalized Lemma in this paper. The results obtained are u seful for the further study on the duality of static programming and cover many already known conditions. 展开更多
关键词 locally star-shaped set right-upper derivative generalized convexity static programming
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A Geometric Proof of the Convexity Preserving Property of NURBS Curves
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作者 LIU Chao-yang 《Chinese Quarterly Journal of Mathematics》 CSCD 北大核心 2006年第1期44-48,共5页
NURBS curves are convexity preserving, i.e. once the control polygon is convex, the associated NURBS curve will also be convex. In this paper this property is proved geometrically.
关键词 convexity preserving knot-insertion Bezier curve NURBS curve
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ON A GENERALIZED MODULUS OF CONVEXITY AND UNIFORM NORMAL STRUCTURE
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作者 杨长森 王丰辉 《Acta Mathematica Scientia》 SCIE CSCD 2007年第4期838-844,共7页
In this article, the authors study a generalized modulus of convexity, δ(α) (ε). Certain related geometrical properties of this modulus are analyzed. Their main result is that Banach space X has uniform normal ... In this article, the authors study a generalized modulus of convexity, δ(α) (ε). Certain related geometrical properties of this modulus are analyzed. Their main result is that Banach space X has uniform normal structure if there exists ε, 0 ≤e≤ 1, such that δ^(α)(1+ε ) 〉 (1- α)ε. 展开更多
关键词 Generalized modulus of convexity uniform normal structure ULTRAPRODUCT
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Extensions of Some Sufficient Conditions for Starlikeness and Convexity of Orderβ
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作者 Xiaoyuan WANG 《Journal of Mathematical Research with Applications》 CSCD 2020年第3期275-286,共12页
The aim of the present paper is to investigate some sufficient conditions for starlikeness and convexity of two new operatorsεα,λ^γand Hm^l(α1)related to the generalized Mittag-Leffler function Eα,λ^γand the g... The aim of the present paper is to investigate some sufficient conditions for starlikeness and convexity of two new operatorsεα,λ^γand Hm^l(α1)related to the generalized Mittag-Leffler function Eα,λ^γand the generalized hypergeometric function,defined in the unit disk,respectively.The results presented here make connections to some of the earlier known developments. 展开更多
关键词 Analytic functions starlike function convexity function generalized Mitttag-Leffler function generalized hypergeometric function
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The Optimality Conditions for Multiobjective Semi-infinite Programming Involving Generalized Unified (C, α, p, d)-convexity
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作者 ZHANG Qing-xiang ZHANG Yong-zhan 《Chinese Quarterly Journal of Mathematics》 CSCD 2013年第2期241-249,共9页
The definition of generalized unified (C, α, ρ, d)-convex function is given. The concepts of generalized unified (C, α, ρ, d)-quasiconvexity, generalized unified (C, α, ρ, d)-pseudoconvexity and generalized unif... The definition of generalized unified (C, α, ρ, d)-convex function is given. The concepts of generalized unified (C, α, ρ, d)-quasiconvexity, generalized unified (C, α, ρ, d)-pseudoconvexity and generalized unified (C, α, ρ, d)-strictly pseudoconvex functions are presented. The sufficient optimality conditions for multiobjective nonsmooth semi-infinite programming are obtained involving these generalized convexity lastly. 展开更多
关键词 generalized convexity multiobjective semi-infinite programming efficient solution optimality conditions
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