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EXTREME POINTS IN DIAGONAL-DISJOINT IDEALS OF NEST ALGEBRAS
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作者 董浙 鲁世杰 《Acta Mathematica Scientia》 SCIE CSCD 2002年第2期222-226,共5页
In this paper, the extreme points of the unit ball of diagonal-disjoint ideals L in nest algebras are characterized completely; Furthermore, it is shown that every extreme point of the unit ball of L has essential-nor... In this paper, the extreme points of the unit ball of diagonal-disjoint ideals L in nest algebras are characterized completely; Furthermore, it is shown that every extreme point of the unit ball of L has essential-norm one. 展开更多
关键词 Diagonal-disjoint ideals extreme points contractive perturbation
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EXTREME POINTS AND SUPPORT POINTS OF A CLASS OF ANALYTIC FUNCTIONS 被引量:2
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作者 彭志刚 刘伦刚 《Acta Mathematica Scientia》 SCIE CSCD 2000年第1期131-136,共6页
Suppose that {b(n)} and {c(n)} are two positive sequences. Let F({b(n)}, {c(n)}) = {f(z) : f(z) is analytic in \z\ < 1, f(z) = z - Sigma(n=2)(+infinity) a(n)z(n), a(n) greater than or equal to 0, Sigma(n=2)(+infini... Suppose that {b(n)} and {c(n)} are two positive sequences. Let F({b(n)}, {c(n)}) = {f(z) : f(z) is analytic in \z\ < 1, f(z) = z - Sigma(n=2)(+infinity) a(n)z(n), a(n) greater than or equal to 0, Sigma(n=2)(+infinity) b(n)a(n) less than or equal to 1 and Sigma(n=2)(+infinity) c(n)a(n) less than or equal to 1}. This article obtains the extreme points and support points of F({b(n)}, {c(n)}). 展开更多
关键词 topology of uniform convergence compact subsets of the unit disk extreme point support point
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THE EXTREME POINTS OF A CLASS OF ANALYTIC FUNCTIONS WITH POSITIVE REAL PART AND A PRESCRIBED SET OF VALUES 被引量:1
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作者 彭志刚 《Acta Mathematica Scientia》 SCIE CSCD 2012年第5期1929-1936,共8页
Letζ =(0,z1,z2,···,zn) with |zj|〈1for1≤j≤n,ω=(1,w1,w2,···,wn),and P(ζ,ω) denote the set of functions p(z) that are analytic in D={z:|z|〈1} and satisfy Rep(z)〉0(|... Letζ =(0,z1,z2,···,zn) with |zj|〈1for1≤j≤n,ω=(1,w1,w2,···,wn),and P(ζ,ω) denote the set of functions p(z) that are analytic in D={z:|z|〈1} and satisfy Rep(z)〉0(|z|〈1),p(0)=1,p(zj)=wj,j=1,2,···,n.In this article we investigate the extreme points of P(ζ,ω). 展开更多
关键词 extreme point positive real part Blaschke product
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THE EXTREME POINTS OF SEVERAL CLASSES OFANALYTIC FUNCTIONS 被引量:1
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作者 彭志刚 《Acta Mathematica Scientia》 SCIE CSCD 1999年第4期457-462,共6页
Let P-n(c(1),c(2),...,c(n-1)) = {p(z) : p(z) is analytic in \z\ < 1 with Rep(z) > 0 and p(z) = 1 + c(1)z + c(2)z(2) +...+ c(n-1)z(n-1) + d(n)z(n) +..., where c(1),c(2),...,c(n-1) are fixed complex constants}. Le... Let P-n(c(1),c(2),...,c(n-1)) = {p(z) : p(z) is analytic in \z\ < 1 with Rep(z) > 0 and p(z) = 1 + c(1)z + c(2)z(2) +...+ c(n-1)z(n-1) + d(n)z(n) +..., where c(1),c(2),...,c(n-1) are fixed complex constants}. Let P-R,P-n(b(1),b(2),...,b(n-1)) = {p(z) : p(z) is analytic in \z\ < 1 with Rep(z) > 0 and p(z) = 1 + b(1)z + b(2)z(2) +...+ b(n-1)z(n-1) + d(n)z(n) +..., where b(1),b(2),...,b(n-1) are fixed real constants and the coefficients of p(z) are real}. Let T-n(l(1),l(2),...,l(n-1)) = {f(z) : f(z) is analytic in \z\ < 1 and f(z) = z + l(1)z(2) + l(2)z(3) +...+ l(n-1)z(n) + d(n)z(n+1) +...; where l(1),l(2),...,l(n-1) are fixed real constants and the coefficients of f(z) are real}. It is understood that P-n(c(1),c(2),...,c(n-1)), P-R,P-n(b(1),b(2),...,b(n-1)) and T-n(l(1),l(2),...,l(n-1)) are not empty when the constants c(k)(k = 1,...,n-1), b(k)(k = 1,2,...,n-1) and l(k)(k = 1,...,n-1) satisfy certain conditions. This paper obtaines the extreme points of P-n(c(1),...,c(n-1)), P-R,P-n(b(1),...,b(n-1)) and T-n(l(1),...,l(n-1)). 展开更多
关键词 Blaschke product extreme point
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THE SUPPORT POINTS AND EXTREME POINTS OF THE UNIT BALL OF H'_P~ 1
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作者 彭志刚 《Acta Mathematica Scientia》 SCIE CSCD 1999年第2期181-189,共9页
By the author denotes the areal measure on the unit disk . Let H'p = {f(z): f(z) is analytic in D and . Let B H 'p and. This article researches the support points and extreme points of B(H'p).
关键词 Topology of uniform convergence compact subsets of unit disk extreme point support point.
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Extreme Points and Strongly Extreme Points of Musielak-Orlicz Sequences Spaces 被引量:5
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作者 XinBoLIU TingFuWANG FeiFeiYU 《Acta Mathematica Sinica,English Series》 SCIE CSCD 2005年第2期267-278,共12页
Criteria for extreme points and strongly extreme points in Musielak-Orliczsequence spaces, equipped with both the Luxemburg norm and the Orlicz norm, are given.
关键词 musielak-orlicz sequence spaces orlicz norm luxemburg norm extreme points strongly extreme points
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A Note on Extreme Points in Dual Spaces
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作者 Juan Francisco MENA-JURADO Juan Carlos NAVARRO-PASCUAL 《Acta Mathematica Sinica,English Series》 SCIE CSCD 2013年第3期471-476,共6页
Given a normed space X it can be easily proven that every extreme point in Bx*, the unit ball of X*, is the restriction of an extreme point in Bx Our purpose is to study when the restrictions of extreme points in B... Given a normed space X it can be easily proven that every extreme point in Bx*, the unit ball of X*, is the restriction of an extreme point in Bx Our purpose is to study when the restrictions of extreme points in Bx*** are extreme points in Bx*. Namely, we characterize Ll-preduals satisfying the aforementioned property. 展开更多
关键词 extreme point Ll-predual M-IDEAL
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THREE KINDS OF DENTABILITIES IN BANACH SPACES AND THEIR APPLICATIONS
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作者 张子厚 周晶 《Acta Mathematica Scientia》 SCIE CSCD 2024年第2期445-454,共10页
In this paper,we study some dentabilities in Banach spaces which are closely related to the famous Radon-Nikodym property.We introduce the concepts of the weak^(*)-weak denting point and the weak^(*)-weak^(*)denting p... In this paper,we study some dentabilities in Banach spaces which are closely related to the famous Radon-Nikodym property.We introduce the concepts of the weak^(*)-weak denting point and the weak^(*)-weak^(*)denting point of a set.These are the generalizations of the weak^(*)denting point of a set in a dual Banach space.By use of the weak^(*)-weak denting point,we characterize the very smooth space,the point of weak^(*)-weak continuity,and the extreme point of a unit ball in a dual Banach space.Meanwhile,we also characterize an approximatively weak compact Chebyshev set in dual Banach spaces.Moreover,we define the nearly weak dentability in Banach spaces,which is a generalization of near dentability.We prove the necessary and sufficient conditions of the reflexivity by nearly weak dentability.We also obtain that nearly weak dentability is equivalent to both the approximatively weak compactness of Banach spaces and the w-strong proximinality of every closed convex subset of Banach spaces. 展开更多
关键词 weak^(*)-weak denting point nearly weak dentability very smooth space point of weak^(*)-weak continuity extreme point approximatively weak compactness w-strong proximinality REFLEXIVITY
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A Solution to the 3x + 1 Problem
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作者 David C. Kay 《American Journal of Computational Mathematics》 2023年第2期371-377,共7页
The author makes the claim to have a solution for the famous 3x + 1 problem. The key to its solution is a special proof that the term (3 + ε)<sup>r</sup> is a non-integer, as well as the use of properties... The author makes the claim to have a solution for the famous 3x + 1 problem. The key to its solution is a special proof that the term (3 + ε)<sup>r</sup> is a non-integer, as well as the use of properties of extremal points of a Collatz sequence. 展开更多
关键词 Collatz Sequences extreme points Pre-extreme Sequence
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q–differ-integral operator on p–valent functions associated with operator on Hilbert space
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作者 Shahram Najafzadeh 《Applied Mathematics(A Journal of Chinese Universities)》 SCIE CSCD 2023年第3期458-466,共9页
Making use of multivalent functions with negative coefficients of the type f (z)=z^(p)-~(∑)_(k=p+1)^(∞)a_(k)z^(k),which are analytic in the open unit disk and applying the q-derivative a q–differintegral operator i... Making use of multivalent functions with negative coefficients of the type f (z)=z^(p)-~(∑)_(k=p+1)^(∞)a_(k)z^(k),which are analytic in the open unit disk and applying the q-derivative a q–differintegral operator is considered.Furthermore by using the familiar Riesz-Dunford integral,a linear operator on Hilbert space H is introduced.A new subclass of p-valent functions related to an operator on H is defined.Coefficient estimate,distortion bound and extreme points are obtained.The convolution-preserving property is also investigated. 展开更多
关键词 multivalent function fractional q–derivative operator fractional q–integral operator Hilbert space coefficient estimate distortion bound extreme point convolution(or Hadamard product)
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Multi-Objective Optimization Algorithm for Grouping Decision Variables Based on Extreme Point Pareto Frontier
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作者 JunWang Linxi Zhang +4 位作者 Hao Zhang Funan Peng Mohammed A.El-Meligy Mohamed Sharaf Qiang Fu 《Computers, Materials & Continua》 SCIE EI 2024年第4期1281-1299,共19页
The existing algorithms for solving multi-objective optimization problems fall into three main categories:Decomposition-based,dominance-based,and indicator-based.Traditional multi-objective optimization problemsmainly... The existing algorithms for solving multi-objective optimization problems fall into three main categories:Decomposition-based,dominance-based,and indicator-based.Traditional multi-objective optimization problemsmainly focus on objectives,treating decision variables as a total variable to solve the problem without consideringthe critical role of decision variables in objective optimization.As seen,a variety of decision variable groupingalgorithms have been proposed.However,these algorithms are relatively broad for the changes of most decisionvariables in the evolution process and are time-consuming in the process of finding the Pareto frontier.To solvethese problems,a multi-objective optimization algorithm for grouping decision variables based on extreme pointPareto frontier(MOEA-DV/EPF)is proposed.This algorithm adopts a preprocessing rule to solve the Paretooptimal solution set of extreme points generated by simultaneous evolution in various target directions,obtainsthe basic Pareto front surface to determine the convergence effect,and analyzes the convergence and distributioneffects of decision variables.In the later stages of algorithm optimization,different mutation strategies are adoptedaccording to the nature of the decision variables to speed up the rate of evolution to obtain excellent individuals,thusenhancing the performance of the algorithm.Evaluation validation of the test functions shows that this algorithmcan solve the multi-objective optimization problem more efficiently. 展开更多
关键词 Multi-objective evolutionary optimization algorithm decision variables grouping extreme point pareto frontier
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A New Class of Harmonic Univalent Functions 被引量:2
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作者 LI Shu-hai MA Li-na 《Chinese Quarterly Journal of Mathematics》 CSCD 2012年第2期286-292,共7页
A complex-valued harmonic function that is univalent and sense preserving in the unit disk U can be written in the form of f = h + g,where h and g are analytic in U.We define and investigate a new class LH_λ(α,β) b... A complex-valued harmonic function that is univalent and sense preserving in the unit disk U can be written in the form of f = h + g,where h and g are analytic in U.We define and investigate a new class LH_λ(α,β) by generalized Salagean operator of harmonic univalent functions.We give sufficient coefficient conditions for normalized harmonic functions in the class LH_λ(α,β).These conditions are also shown to be necessary when the coefficients are negative.This leads to distortion bounds and extreme points. 展开更多
关键词 harmonic function Salagean operator extreme points distortion bounds
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Some Properties for New Subclass of Analytic Functions 被引量:1
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作者 TANG Huo LI Shu-hai +1 位作者 DENG Guan-tie MA Li-na 《Chinese Quarterly Journal of Mathematics》 CSCD 2013年第2期261-268,共8页
A new subclass A(β1 , β2 , ··· , βk ; λ) of analytic functions f(z) in the open unit disk U is introduced and studied. We provide coefficient inequalities, distortion theorems, extreme points and ra... A new subclass A(β1 , β2 , ··· , βk ; λ) of analytic functions f(z) in the open unit disk U is introduced and studied. We provide coefficient inequalities, distortion theorems, extreme points and radius of close-to-convexity, starlikeness and convexity of this class. 展开更多
关键词 analytic functions coefficient inequalities distortion inequalities extreme points RADIUS
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Rotundity of Orlicz-Bochner Space with Luxemburg Norm 被引量:7
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作者 刘玉霞 石忠锐 张品 《Journal of Shanghai University(English Edition)》 CAS 2003年第4期322-326,共5页
In this paper, by using the generating function Φ and X the criteria of the rotundity for the Orlicz-Bochner function and sequence spaces endowed with the Luxemburg norm were obtained. And the sufficient and necessar... In this paper, by using the generating function Φ and X the criteria of the rotundity for the Orlicz-Bochner function and sequence spaces endowed with the Luxemburg norm were obtained. And the sufficient and necessary conditions were given for the extreme point of Orlicz-Bochner sequence space and the conditions in part for Orlicz-Bochner function space. 展开更多
关键词 extreme point ROTUNDITY Orlicz-Bochner space Luxemgury norm.
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Multi-point Contact of the High-speed Vehicle-turnout System Dynamics 被引量:5
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作者 REN Zunsong 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2013年第3期518-525,共8页
The wheel-rail contact problems, such as the number, location and the track of contact patches, are very important for optimizing the spatial structure of the rails and lowering the vehicle-turnout system dynamics. Ho... The wheel-rail contact problems, such as the number, location and the track of contact patches, are very important for optimizing the spatial structure of the rails and lowering the vehicle-turnout system dynamics. However, the above problems are not well solved currently because of having the difficulties in how to determine the multi-contact, to preciously present the changeable profiles of the rails and to establish an accurate spatial turnout system dynamics model. Based on a high-speed vehicle-turnout coupled model in which the track is modeled as flexible with rails and sleepers represented by beams, the line tracing extreme point method is introduced to investigate the wheel-rail multiple contact conditions and the key sections of the blade rail, longer nose rail, shorter rail in the switch and nose rail area are discretized to represent the varying profiles of rails in the turnout. The dynamic interaction between the vehicle and turnout is simulated for cases of the vehicle divergently passing the turnout and the multi-point contact is obtained. The tracks of the contact patches on the top of the rails are presented and the wheel-rail impact forces are offered in comparison with the contact patches transference on the rails. The numerical simulation results indicate that the length of two-point contact occurrence of a worn wheel profile and rails is longer than that of the new wheel profile and rails; The two-point contact definitely occurs in the switch and crossing area. Generally, three-point contact doesn’t occur for the new rail profile, which is testified by the wheel-rails interpolation distance and the first order derivative function of the tracing line extreme points. The presented research is not only helpful to optimize the structure of the turnout, but also useful to lower the dynamics of the high speed vehicle-turnout system. 展开更多
关键词 line tracing extreme point method multi-point contact high-speed vehicle-turnout system track of contact point on rails wheel-rail force transference
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A New Class of Harmonic Univalent Functions by the Generalized Salagean Operator 被引量:6
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作者 LI Shuhai LIU Peide 《Wuhan University Journal of Natural Sciences》 CAS 2007年第6期965-970,共6页
A complex-valued harmonic functions that are univalent and sense preserving in the unit disk U can be written in the form f = h + g^-, where h and g are analytic in U. We define and investigate a new class SHPλ(α... A complex-valued harmonic functions that are univalent and sense preserving in the unit disk U can be written in the form f = h + g^-, where h and g are analytic in U. We define and investigate a new class SHPλ(α,β)by generalized Salagean operator of harmonic univalent functions. We give sufficient coefficient conditions for normalized harmonic functions in the class SHPλ(α,β) These conditions are also shown to be necessary when the coefficients are negative. This leads to distortion bounds and extreme points. 展开更多
关键词 harmonic function Salagean operator extreme point distortion bounds
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THE ISOMETRIC EXTENSION OF AN INTO MAPPING FROM THE UNIT SPHERE S[e(Γ)] TO THE UNIT SPHERE S(E) 被引量:6
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作者 定光桂 《Acta Mathematica Scientia》 SCIE CSCD 2009年第3期469-479,共11页
This is such a article to consider an "into" isometric mapping between two unit spheres of two infinite dimensional spaces of different types. In this article, we find a useful condition (using the Krein-Milman pro... This is such a article to consider an "into" isometric mapping between two unit spheres of two infinite dimensional spaces of different types. In this article, we find a useful condition (using the Krein-Milman property) under which an into-isometric mapping from the unit sphere of e(Γ) to the unit sphere of a normed space E can be linearly isometric extended. 展开更多
关键词 isometric extension extreme point Krein—Milman property
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SOME PROPERTIES FOR CERTAIN CLASSES OF UNIVALENT FUNCTIONS DEFINED BY DIFFERENTIAL INEQUALITIES 被引量:1
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作者 彭志刚 钟广祯 《Acta Mathematica Scientia》 SCIE CSCD 2017年第1期69-78,共10页
Let A be the space of functions analytic in the unit disk D = {z:|z| 〈 1}.Let U denote the set of all functions f ∈ A satisfying the conditions f(0) = f'(0)-1 = 0 and|f'(z)(z/f(z))2-1|〈1(|z|〈1... Let A be the space of functions analytic in the unit disk D = {z:|z| 〈 1}.Let U denote the set of all functions f ∈ A satisfying the conditions f(0) = f'(0)-1 = 0 and|f'(z)(z/f(z))2-1|〈1(|z|〈1).Also,let Ω denote the set of all functions f ∈ A satisfying the conditions f(0) = f'(0)-1 = 0and|zf'(z)-f(z)|〈1/2(|z|〈1).In this article,we discuss the properties of U and Ω. 展开更多
关键词 univalent function Starlike function Hadamard product extreme point sup-port point
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Statistical Convergence and Measure Convergence Generated by a Single Statistical Measure 被引量:1
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作者 Li Xin CHENG Li Hua LIN Xian Geng ZHOU 《Acta Mathematica Sinica,English Series》 SCIE CSCD 2016年第6期668-682,共15页
The purpose of this paper is to discuss those kinds of statistical convergence, in terms of F , or ideal Z-convergence, which are equivalent to measure convergence defined by a single statistical measure. We prove a n... The purpose of this paper is to discuss those kinds of statistical convergence, in terms of F , or ideal Z-convergence, which are equivalent to measure convergence defined by a single statistical measure. We prove a number of characterizations of a single statistical measure μ-convergence by using properties of its corresponding quotient Banach space l∞/l∞ (Iμ). We also show that the usual sequential convergence is not equivalent to a single measure convergence. 展开更多
关键词 Statistical measure ULTRAFILTER extreme points statistical convergence
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A Generalized Vector-valued Variational Principle in Fréchet Spaces
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作者 Jing Hui QIU Xin Qing YANG 《Acta Mathematica Sinica,English Series》 SCIE CSCD 2010年第11期2145-2156,共12页
In the framework of Frechet spaces, we give a generalized vector-valued Ekeland's variational principle, where the perturbation involves the subadditive functions of countable generating semi-norms. By modifying and ... In the framework of Frechet spaces, we give a generalized vector-valued Ekeland's variational principle, where the perturbation involves the subadditive functions of countable generating semi-norms. By modifying and developing the method of Cammaroto and Chinni, we obtain a density theorem on extremal points of the vector-valued variational principle, which extends and improves the related known results. 展开更多
关键词 Locally convex space Fr^chet space vector-valued variational principle extremal point density
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