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Space Topologies and Their Dual Space Topologies for Conventional Functional Space Topologies
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作者 Mahjoub A. Elamin 《Journal of Applied Mathematics and Physics》 2024年第3期778-804,共27页
In this paper, we have studied the topology of some classical functional spaces. Among these spaces, there are standard spaces, spaces that can be metrizable and others that cannot be metrizable. But they are all topo... In this paper, we have studied the topology of some classical functional spaces. Among these spaces, there are standard spaces, spaces that can be metrizable and others that cannot be metrizable. But they are all topological vector spaces and it is in this context that we have chosen to present this work. We are interested in the topology of its spaces and in the topologies of their dual spaces. The first part, we presented the fundamental topological properties of topological vector spaces. The second part, we studied Frechet spaces and particularly the space S(R<sup>n</sup>) of functions of class C<sup>∞ </sup>on R<sup>n</sup> which are as well as all their rapidly decreasing partial derivatives. We have also studied its dual S'(Rn</sup>) the space of tempered distributions. The last part aims to define a topological structure on an increasing union of Frechet spaces called inductive limit of Frechet spaces. We study in particular the space D(Ω) of functions of class C<sup>∞</sup> with compact supports on Ω as well as its dual D' (Ω) the space distributions over the open set Ω. 展开更多
关键词 linear Forms Dual spaces Frechet spaces Partial Derivatives DISTRIBUTIONS Topological Structure Weak Topology Strong Topology
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《Metric Linear Spaces》的两点注记
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作者 王见勇 《常熟高专学报》 2002年第2期13-16,共4页
指出StefanRolewicz先生的名著《MetricLinearSpaces》中的三个定理的证明错误 。
关键词 度量线性空间 σ-有限测度空间 连续嵌入 实心F*-空间 最大不友好 凹性模
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从Place连接Space助推“机械原理”一流课程建设
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作者 仝美娟 解妙霞 耿素花 《教育教学论坛》 2023年第30期161-164,共4页
基于教学实践,从教学内容、教学组织和双向评价这三个关键维度出发,分别在先进理论和现代设计方法、大规模在线教育和工程实践及教师评价“学”的过程和学生评价“教”的过程等重要方向建立连接,使课程体系从有限容量的线性place占位扩... 基于教学实践,从教学内容、教学组织和双向评价这三个关键维度出发,分别在先进理论和现代设计方法、大规模在线教育和工程实践及教师评价“学”的过程和学生评价“教”的过程等重要方向建立连接,使课程体系从有限容量的线性place占位扩展到大容量现代化教学的多方向space占位。建设结果表明,多方向的space课程体系既能解决学生学习过程中的主动性、积极性问题,又能助推课程自身迭代,促使“机械原理”始终处于一流课程的领先地位。 展开更多
关键词 教学组织 双向评价 线性place 多向space
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THE COAPPROXIMATION IN LINEAR SPACES 被引量:1
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作者 Son Wenhua Dalian University of Technology,China 《Analysis in Theory and Applications》 1993年第4期55-65,共11页
In this paper,we investigate the properties of strongly coapproximation in normed linear spaces and lo- cally,convex spaces.The relations between strongly coapproximation and strongly unique approximation and of the f... In this paper,we investigate the properties of strongly coapproximation in normed linear spaces and lo- cally,convex spaces.The relations between strongly coapproximation and strongly unique approximation and of the f-coapproximation and f-approximation,are also considered. 展开更多
关键词 TH THE COAPPROXIMATION IN linear spaceS
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CHARACTERIZATION OF BEST APPROXIMATIONS IN METRIC LINEAR SPACES
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作者 Sizwe Mabizela 《Analysis in Theory and Applications》 2003年第2期121-129,共9页
Let (X,d) be a real metric linear space, with translation-invariant metric d and C a linear subspace of X. In this paper we use functionals in the Lipschitz dual of X to characterize those elements of G which are best... Let (X,d) be a real metric linear space, with translation-invariant metric d and C a linear subspace of X. In this paper we use functionals in the Lipschitz dual of X to characterize those elements of G which are best approximations to elements of X.We also give simultaneous characterization of elements of best approximation and also consider elements of ε-approximation. 展开更多
关键词 metric linear space Lipschitz dual best approximation metric projection proximinal set Chebyshev set ε-approximation
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Angles of Norm ed Linear Spaces and Characterizations of Inner Product Spaces
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作者 郑永爱 《Chinese Quarterly Journal of Mathematics》 CSCD 1998年第1期70-73, ,共4页
In [1],a family of angles are defined in normed linear spaces. In this paper,it is shown that if anyone of the angles satisfies certain euclidean triangle congruence properties,the space must be an inner product space.
关键词 ANGLE normed linear space inner product space ORTHOGONALITY
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Krein space approach to robust H_∞ filtering for linear uncertain systems
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作者 Jin Feng Fei Yu +2 位作者 Na Yang Pengyu Zhang Wei Gao 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2012年第4期596-602,共7页
A novel Krein space approach to robust H∞ filtering for linear uncertain systems is developed. The parameter uncertainty, entering into both states and measurement equations, satisfies an energy-type constraint. Then... A novel Krein space approach to robust H∞ filtering for linear uncertain systems is developed. The parameter uncertainty, entering into both states and measurement equations, satisfies an energy-type constraint. Then a Krein space approach is used to tackle the robust H∞ filtering problem. To this end, a new Krein space formal system is designed according to the original sum quadratic constraint (SQC) without introducing any nonzero factors into it and, consequently, the estimate recursion is obtained through the filter gain in Krein space. Finally, a numerical example is given to demonstrate the effectiveness of the proposed approach. 展开更多
关键词 linear uncertain system sum quadratic constraint(SQC) robust H∞ filtering Krein space linear estimation.
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A NEW PERTURBATION THEOREM FOR MOORE-PENROSE METRIC GENERALIZED INVERSE OF BOUNDED LINEAR OPERATORS IN BANACH SPACES 被引量:3
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作者 王紫 王玉文 《Acta Mathematica Scientia》 SCIE CSCD 2017年第6期1619-1631,共13页
In this paper, we investigate a new perturbation theorem for the Moore-Penrose metric generalized inverses of a bounded linear operator in Banach space. The main tool in this paper is "the generalized Neumann lemma"... In this paper, we investigate a new perturbation theorem for the Moore-Penrose metric generalized inverses of a bounded linear operator in Banach space. The main tool in this paper is "the generalized Neumann lemma" which is quite different from the method in [12] where "the generalized Banach lemma" was used. By the method of the perturba- tion analysis of bounded linear operators, we obtain an explicit perturbation theorem and three inequalities about error estimates for the Moore-Penrose metric generalized inverse of bounded linear operator under the generalized Neumann lemma and the concept of stable perturbations in Banach spaces. 展开更多
关键词 Banach space bounded linear operator metric projection generalized inverse perturbation analysis Moore-Penrose quasi-additive
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More Properties of Semi-Linear Uniform Spaces
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作者 S. A. Alhihi 《Applied Mathematics》 2015年第6期1069-1075,共7页
In this paper we shall generalize the definition given in [1] for Lipschitz condition and contractions for functions on a non-metrizable space, besides we shall give more properties of semi-linear uniform spaces.
关键词 LIPSCHITZ Condition CONTRACTIONS Not METRIZABLE spaceS SEMI-linear spaceS UNIFORM spaceS Fixed Point
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The Related Properties of Generalized Orthogonal Group in Specific Normed Linear Spaces
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作者 Siyuan Wu 《Journal of Applied Mathematics and Physics》 2022年第1期1-10,共10页
Firstly, in the general normed linear space, the concepts of generalized isosceles orthogonal group, generalized Birkhoff orthogonal group, generalized Roberts orthogonal group, strong Birkhoff orthogonal group and ge... Firstly, in the general normed linear space, the concepts of generalized isosceles orthogonal group, generalized Birkhoff orthogonal group, generalized Roberts orthogonal group, strong Birkhoff orthogonal group and generalized orthogonal basis are introduced. Secondly, the conclusion that any two nonzero generalized orthogonal groups must be linearly independent group is proven. And the existence of nonzero generalized orthogonal group and its linear correlation are discussed preliminarily, as well as some related properties of nonempty generalized orthogonal group in specific normed linear space namely the <em>l<sub>p</sub></em> space. 展开更多
关键词 Normed linear space Generalized Orthogonal Group Generalized Birkhoff Orthogonal Group Generalized Isosceles Orthogonal Group Generalized Roberts Orthogonal Group
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ON PROBABILISTIC NORM OF A LINEAR OPERATORS AND SPACE OF OPERATORS
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作者 方锦暄 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI 1999年第10期1160-1166,共7页
Since the PN space (E, F) which satisfies condition (PN-5) is just a Menger PN-space (E, F, min), the results with regard to probabilistic norms of linear operators on PN-spaces obtained by Xiao Jianzhong have bigger ... Since the PN space (E, F) which satisfies condition (PN-5) is just a Menger PN-space (E, F, min), the results with regard to probabilistic norms of linear operators on PN-spaces obtained by Xiao Jianzhong have bigger limitations. In this paper, problems respecting probabilistic norms of linear operators and spaces of operators are studied on more general Menger PN-spaces. The results presented improve and generalize the corresponding results by Xiao. 展开更多
关键词 probabilistic normed space probabilistic norm of a linear operator space of operators
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CHEBYSHEV CENTERS PROXIMINALITY AND FARTHEST POINTS IN STRONG NORMED ALMOST LINEAR SPACES
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作者 Geetha S. Rao T. L. Bhaskaramurthi 《Analysis in Theory and Applications》 1997年第4期99-111,共13页
Some results from the theory of best (or best simultaneous) approximation in a narmed linear space have been extended to a normed almost linear space [strong normed almost linear space].
关键词 CHEBYSHEV CENTERS PROXIMINALITY AND FARTHEST POINTS IN STRONG NORMED ALMOST linear spaceS
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Composition Operators with Linear Fractional Symbols on Vector-Valued Bergman Spaces 被引量:1
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作者 WangMao-fa UuPei-de ZhouShao-bo 《Wuhan University Journal of Natural Sciences》 CAS 2003年第03A期759-764,共6页
Let φ and ψ be linear fractional self\|maps of the unit disk D and X a separable Hilbert space. In this paper we completely characterize the weak compactness of the product operators of a composition operation C φ... Let φ and ψ be linear fractional self\|maps of the unit disk D and X a separable Hilbert space. In this paper we completely characterize the weak compactness of the product operators of a composition operation C φ with another one's adjoint C * ψ on the vector\|valued Bergman space B 1(X) for forms C φC * ψ and C * ψC φ. 展开更多
关键词 vector\|valued Bergman space composition operator linear fractional map angular derivative weak compactness
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ON CONDITIONS FOR THE NON LOCALLY CONVEX LINEAR TOPOLOGICAL SPACE TO HAVE THE H.-B. EXTENSION PROPERTY
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作者 SuLinning 《数学研究》 CSCD 1994年第1期158-162,共5页
ONCONDITIONSFORTHENONLOCALLYCONVEXLINEARTOPOLOGICALSPACETOHAVETHEH.-B.EXTENSIONPROPERTY¥SuLinning(Dept.ofMat... ONCONDITIONSFORTHENONLOCALLYCONVEXLINEARTOPOLOGICALSPACETOHAVETHEH.-B.EXTENSIONPROPERTY¥SuLinning(Dept.ofMath.,NingdeTeacher'... 展开更多
关键词 线性拓扑空间 线性连续函数 展开式性质 共轭独立
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Factorization of Operators in Krein Spaces and Linear-Fractional Relations of Operator Balls
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作者 Victor Anatoly Khatskevich Valery Anatoly Senderov 《Advances in Pure Mathematics》 2013年第1期29-33,共5页
We consider plus-operators in Krein spaces and generated operator linear fractional relations of the following form: . We study some special type of factorization for plus-operators T, among them the following one: T ... We consider plus-operators in Krein spaces and generated operator linear fractional relations of the following form: . We study some special type of factorization for plus-operators T, among them the following one: T = BU, where B is a lower triangular plus-operator, U is a J-unitary operator. We apply the above factorization to the study of basical properties of relations (1), in particular, convexity and compactness of their images with respect to the weak operator topology. Obtained results we apply to the known Koenigs embedding problem, the Krein-Phillips problem of existing of invariant semidefinite subspaces for some families of plus-operators and to some other fields. 展开更多
关键词 Krein space linear FRACTIONAL Relation Plus-Operator FACTORIZATION
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Linear Dispersion Orthogonal Space-Time Block Codes
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作者 高明 葛建华 李靖 《Journal of Beijing Institute of Technology》 EI CAS 2010年第3期357-361,共5页
A new architecture of space-time codes as a combination of orthogonal space-time block codes (OSTBC) and linear dispersion codes (LDC) is proposed in order to improve the bit error rate(BER) performance of OSTBC... A new architecture of space-time codes as a combination of orthogonal space-time block codes (OSTBC) and linear dispersion codes (LDC) is proposed in order to improve the bit error rate(BER) performance of OSTBC.The scheme proposed is named linear dispersion orthogonal space-time block codes (LDOSTBC).In LDOSTBC scheme,firstly,the data is coded into LDC codewords.Then,the coded LDC substreams are coded into OSTBC codewords again.The decoding algorithm of LDOSTBC combines linear decoding of OSTBC and ML decoding or suboptimum detection algorithms of LDC.Compared with OSTBC scheme when the rate of LDC is MtR,the performance of LDOSTBC scheme can be improved without decreasing the data rate,where Mt is the number of transmit antennas and R is the spectral efficiency of the modulation constellation.If some rate penalty is allowed,when the rate of LDC is less than MtR the performance of LDOSTBC can be improved further. 展开更多
关键词 space-time coding linear dispersion codes (LDC) orthogonal space-time block codes (OSTBC)
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THE CONTRACTION LINEAR METRIC PROJECTIONS IN L_p SPACES
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作者 Song Wenhua (Hebei University of Economics, China) 《Approximation Theory and Its Applications》 2002年第4期20-30,共11页
In this paper, we study the contraction linearity for metric projection in L p spaces. A geometrical property of a subspace Y of L p is given on which P Y is a contraction projection.
关键词 THE CONTRACTION linear METRIC PROJECTIONS IN L_p spaceS
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Computational Analysis for Solving the Linear Space-Fractional Telegraph Equation
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作者 Zaki Mrzog Alaofi Talaat Sayed El-Danaf +1 位作者 Adel Hadhoud Silvestru Sever Dragomir 《Open Journal of Modelling and Simulation》 2022年第3期267-282,共16页
Over the last few years, there has been a significant increase in attention paid to fractional differential equations, given their wide array of applications in the fields of physics and engineering. The recent develo... Over the last few years, there has been a significant increase in attention paid to fractional differential equations, given their wide array of applications in the fields of physics and engineering. The recent development of using fractional telegraph equations as models in some fields (e.g., the thermal diffusion in fractal media) has heightened the importance of examining the method of solutions for such equations (both approximate and analytic). The present work is designed to serve as a valuable contribution to work in this field. The key objective of this work is to propose a general framework that can be used to guide quadratic spline functions in order to create a numerical method for obtaining an approximation solution using the linear space-fractional telegraph equation. Additionally, the Von Neumann method was employed to measure the stability of the analytical scheme, which showed that the proposed method is conditionally stable. What’s more, the proposal contains a numerical example that illustrates how the proposed method can be implemented practically, whilst the error estimates and numerical stability results are discussed in depth. The findings indicate that the proposed model is highly effective, convenient and accurate for solving the relevant problems and is suitable for use with approximate solutions acquired through the two-dimensional differential transform method that has been developed for linear partial differential equations with space- and time-fractional derivatives. 展开更多
关键词 Fractional Differential Equations Quadratic Spline Functions linear space-Fractional Telegraph Equation Von Neumann Stability
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Feedback Systems on a Reflexive Banach Space—Linearization
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作者 Messaoudi Khelifa 《International Journal of Modern Nonlinear Theory and Application》 2020年第2期34-50,共17页
The aim of our work is to formulate and demonstrate the results of the normality, the Lipschitz continuity, of a nonlinear feedback system described by the monotone maximal operators and hemicontinuous, defined on rea... The aim of our work is to formulate and demonstrate the results of the normality, the Lipschitz continuity, of a nonlinear feedback system described by the monotone maximal operators and hemicontinuous, defined on real reflexive Banach spaces, as well as the approximation in a neighborhood of zero, of solutions of a feedback system [A,B] assumed to be non-linear, by solutions of another linear, This approximation allows us to obtain appropriate estimates of the solutions. These estimates have a significant effect on the study of the robust stability and sensitivity of such a system see <a href="#ref1">[1]</a> <a href="#ref2">[2]</a> <a href="#ref3">[3]</a>. We then consider a linear FS <img src="Edit_4629d4d0-bbb2-478d-adde-391efde3d1e0.bmp" alt="" />, and prove that, if <img src="Edit_435aae08-e821-4b4d-99d2-e2a2b47609c1.bmp" alt="" />;<img src="Edit_4fa030bc-1f97-4726-8257-ca8d00657aac.bmp" alt="" /> , with <img src="Edit_63ab4faa-ba40-45fe-8b8a-7a6caef91794.bmp" alt="" />the respective solutions of FS’s [A,B] and <img src="Edit_e78e2e6d-8934-4011-93eb-8b7eb52fa856.bmp" alt="" /> corresponding to the given (u,v) in <img src="Edit_0e18433c-8c7a-454f-8eec-6eb9fb69469a.bmp" alt="" /> . There exists,<img src="Edit_3dcd8afc-8cea-4c06-a920-e4148a5f793e.bmp" alt="" />, positive real constants such that, <img src="Edit_edb88446-3e39-4fe0-865a-114de701e78e.bmp" alt="" />. These results are the subject of theorems 3.1, <span style="font-size:10.0pt;font-family:;" "="">... </span>, 3.3. The proofs of these theorems are based on our lemmas 3.2, <span style="font-size:10.0pt;font-family:;" "="">... </span>, 3.5, devoted according to the hypotheses on A and B, to the existence of the inverse of the operator <em>I+BA</em> and <img src="Edit_2db1326b-cb5b-44cf-8d1f-df22bd6da45f.bmp" alt="" />. The results obtained and demonstrated along this document, present an extension in general Banach space of those in <a href="#ref4">[4]</a> on a Hilbert space <em>H</em> and those in <a href="#ref5">[5]</a> on a extended Hilbert space <img src="Edit_b70ce337-1812-4d4b-ae7d-a24da7e5b3cf.bmp" alt="" />. 展开更多
关键词 Nonlinear Feedback System linearIZATION Reflexive Banach space NORMALITY Lipschitz Continuity
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ON THE DECOMPOSITION OF COMPLEX VECTOR SPACES AND THE JORDAN CANONICAL FORM OF COMPLEX LINEAR TRANSFORMATIONS
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作者 肖衡 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI 1994年第11期997-1003,共7页
New objects characterizing the structure of complex linear transformations areintroduced. These new objects yield a new result for the decomposition of complexvector spaces relative to complex lrnear transformations a... New objects characterizing the structure of complex linear transformations areintroduced. These new objects yield a new result for the decomposition of complexvector spaces relative to complex lrnear transformations and provide all Jordan basesby which the Jordan canonical form is constructed. Accordingly, they can result in thecelebrated Jordan theorem and the third decomposition theorem of space directly. and,moreover, they can give a new deep insight into the exquisite and subtle structure ofthe Jordan form. The latter indicates that the Jordan canonical form of a complexlinear transformation is an invariant structure associated with double arbitrary. choices. 展开更多
关键词 complex vector space complex linear transformation. decompo-sition theorems. Jordan canonical form
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