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A trichotomy for a class of equivalence relations
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作者 DING LongYun 《Science China Mathematics》 SCIE 2012年第12期2621-2630,共10页
Let Xn, n ∈ N be a sequence of non-empty sets, ψn : Xn2 → IR+. We consider the relation E = E((Xn, ψn)n∈N) on ∏n∈N Xn by (x, y) ∈ E((Xn, ψn)n∈N) <=>Σn∈Nψn(x(n), y(n)) < +∞. If E is an equiv- ale... Let Xn, n ∈ N be a sequence of non-empty sets, ψn : Xn2 → IR+. We consider the relation E = E((Xn, ψn)n∈N) on ∏n∈N Xn by (x, y) ∈ E((Xn, ψn)n∈N) <=>Σn∈Nψn(x(n), y(n)) < +∞. If E is an equiv- alence relation and all ψn, n ∈ N, are Borel, we show a trichotomy that either IRN/e1≤B E, E1≤B E, or E≤B E0. We also prove that, for a rather general case, E((Xn, ψn)n∈N) is an equivalence relation iff it is an ep-like equivalence relation. 展开更多
关键词 Borel reducibility equivalence relation METRIZATION
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Borel Equivalence Relations between l_1and l_p
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作者 Long Yun DING Zhi YIN 《Acta Mathematica Sinica,English Series》 SCIE CSCD 2013年第12期2391-2396,共6页
In this paper, we show that, for each p 〉 1, there are continuum many Borel equivalence relations between Rω/l1 and Rω/p ordered by ≤B which are pairwise Borel incomparable.
关键词 Borel equivalence relation Borel reducibility
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Effect of Gravitational Formula Change on Gravitational Anomalies
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作者 Hans Peter Weber 《Journal of Modern Physics》 2024年第11期1632-1645,共14页
The gravitational constant G is a basic quantity in physics, and, despite its relative imprecision, appears in many formulas, for example, also in the formulas of the Planck units. The “relative inaccuracy” lies in ... The gravitational constant G is a basic quantity in physics, and, despite its relative imprecision, appears in many formulas, for example, also in the formulas of the Planck units. The “relative inaccuracy” lies in the fact that each measurement gives different values, depending on where and with which device the measurement is taken. Ultimately, the mean value was formed and agreed upon as the official value that is used in all calculations. In an effort to explore the reason for the inaccuracy of this quantity, some formulas were configured using G, so that the respective quantity assumed the value = 1. The gravitational constant thus modified was also used in the other Planck equations instead of the conventional G. It turned out that the new values were all equivalent to each other. It was also shown that the new values were all represented by powers of the speed of light. The G was therefore no longer needed. Just like the famous mass/energy equivalence E = m * c2, similar formulas emerged, e.g. mass/momentum = m * c, mass/velocity = m * c2 and so on. This article takes up the idea that emerges in the article by Weber [1], who describes the gravitational constant as a variable (Gvar) and gives some reasons for this. Further reasons are given in the present paper and are computed. For example, the Planck units are set iteratively with the help of the variable Gvar, so that the value of one unit equals 1 in each case. In this article, eleven Planck units are set iteratively using the variable Gvar, so that the value of one unit equals 1 in each case. If all other units are based on the Gvar determined in this way, a matrix of values is created that can be regarded both as conversion factors and as equivalence relationships. It is astonishing, but not surprising that the equivalence relation E = m * c2 is one of these results. All formulas for these equivalence relationships work with the vacuum speed of light c and a new constant K. G, both as a variable and as a constant, no longer appears in these formulae. The new thing about this theory is that the gravitational constant is no longer needed. And if it no longer exists, it can no longer cause any difficulties. The example of the Planck units shows this fact very clearly. This is a radical break with current views. It is also interesting to note that the “magic” number 137 can be calculated from the distances between the values of the matrix. In addition, a similar number can be calculated from the distances between the Planck units. This number is 131 and differs from 137 with 4.14 percent. This difference has certainly often led to confusion, for example, when measuring the Fine Structure Constant. 展开更多
关键词 System of Units Planck Constants Gravitational Constant Variable Gravitation equivalence relations Number 137
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The Equivalence between Orthogonal Iterations and Alternating Least Squares 被引量:1
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作者 Achiya Dax 《Advances in Linear Algebra & Matrix Theory》 2020年第2期7-21,共15页
This note explores the relations between two different methods. The first one is the Alternating Least Squares (ALS) method for calculating a rank<em>-k</em> approximation of a real <em>m</em>&... This note explores the relations between two different methods. The first one is the Alternating Least Squares (ALS) method for calculating a rank<em>-k</em> approximation of a real <em>m</em>×<em>n</em> matrix, <em>A</em>. This method has important applications in nonnegative matrix factorizations, in matrix completion problems, and in tensor approximations. The second method is called Orthogonal Iterations. Other names of this method are Subspace Iterations, Simultaneous Iterations, and block-Power method. Given a real symmetric matrix, <em>G</em>, this method computes<em> k</em> dominant eigenvectors of <em>G</em>. To see the relation between these methods we assume that <em>G </em>=<em> A</em><sup>T</sup> <em>A</em>. It is shown that in this case the two methods generate the same sequence of subspaces, and the same sequence of low-rank approximations. This equivalence provides new insight into the convergence properties of both methods. 展开更多
关键词 Alternating Least Squares (ALS) Orthogonal Iterations equivalence relations Low-Rank Approximations
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Einstein’s Dark Energy via Similarity Equivalence, ‘tHooft Dimensional Regularization and Lie Symmetry Groups 被引量:4
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作者 Mohamed S. El Naschie 《International Journal of Astronomy and Astrophysics》 2016年第1期56-81,共26页
Realizing the physical reality of ‘tHooft’s self similar and dimensionaly regularized fractal-like spacetime as well as being inspired by a note worthy anecdote involving the great mathematician of Alexandria, Pytha... Realizing the physical reality of ‘tHooft’s self similar and dimensionaly regularized fractal-like spacetime as well as being inspired by a note worthy anecdote involving the great mathematician of Alexandria, Pythagoras and the larger than life man of theoretical physics Einstein, we utilize some deep mathematical connections between equivalence classes of equivalence relations and E-infinity theory quotient space. We started from the basic principles of self similarity which came to prominence in science with the advent of the modern theory of nonlinear dynamical systems, deterministic chaos and fractals. This fundamental logico-mathematical thread related to partially ordered sets is then applied to show how the classical Newton’s kinetic energy E = 1/2mv<sup>2</sup> leads to Einstein’s celebrated maximal energy equation E = mc<sup>2</sup> and how in turn this can be dissected into the ordinary energy density E(O) = mc<sup>2</sup>/22 and the dark energy density E(D) = mc<sup>2</sup>(21/22) of the cosmos where m is the mass;v is the velocity and c is the speed of light. The important role of the exceptional Lie symmetry groups and ‘tHooft-Veltman-Wilson dimensional regularization in fractal spacetime played in the above is also highlighted. The author hopes that the unusual character of the analysis and presentation of the present work may be taken in a positive vein as seriously attempting to propose a different and new way of doing theoretical physics by treating number theory, set theory, group theory, experimental physics as well as conventional theoretical physics on the same footing and letting all these diverse tools lead us to the answer of fundamental questions without fear of being labelled in one way or another. 展开更多
关键词 equivalence Relation SCALING Intermediate Asymptotic Golden Mean Scaling Einstein Self Similarity Fractal Scaling E-INFINITY Special Relativity Random Cantor Sets ‘tHooft Regularization Fractal Quantum Field Quantum Gravity Exceptional Lie Symmetry Groups
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The application of fuzzy equivalence relation based on the quotient space in cluster analysis
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作者 SHEN Qin-wei ZHANG Yuan 《International Journal of Technology Management》 2014年第8期58-61,共4页
A fuzzy clustering analysis model based on the quotient space is proposed. Firstly, the conversion from coarse to fine granularity and the hierarchical structure are used to reduce the multidimensional samples. Second... A fuzzy clustering analysis model based on the quotient space is proposed. Firstly, the conversion from coarse to fine granularity and the hierarchical structure are used to reduce the multidimensional samples. Secondly, the fuzzy compatibility relation matrix of the model is converted into fuzzy equivalence relation matrix. Finally, the diagram of clustering genealogy is generated according to the fuzzy equivalence relation matrix, which enables the dynamic selection of different thresholds to effectively solve the problem of cluster analysis of the samples with multi-dimensional attributes. 展开更多
关键词 quotient space hierarchical structure fuzzy compatibility relation fuzzy equivalence relation matrix cluster analysis
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IMPROVED ACCURACY AND ROUGHNESS MEASURES FOR ROUGH SETS 被引量:2
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作者 ZhouYuming XuBaowen 《Journal of Electronics(China)》 2002年第3期320-323,共4页
Accuracy and roughness, proposed by Pawlak(1982), might draw a conclusion inconsistent with our intuition in some cases. This letter analyzes the limitations in these measures and proposes improved accuracy and roughn... Accuracy and roughness, proposed by Pawlak(1982), might draw a conclusion inconsistent with our intuition in some cases. This letter analyzes the limitations in these measures and proposes improved accuracy and roughness measures based on information theory. 展开更多
关键词 Rough sets equivalence relations UNCERTAINTY Information theory Excess entropy
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How Hermann Weyl Could Deal with Paul Benacerraf's (1973) Challenge to Realism?
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作者 Christopoulou Demetra 《Journal of Philosophy Study》 2013年第8期715-723,共9页
Christopoulou Demetra(In his work, Hermann Weyl (1926) addresses the issue of abstraction principles, an issue that has been broadly discussed during the last decades with regard to the Neo-Fregean program. This pa... Christopoulou Demetra(In his work, Hermann Weyl (1926) addresses the issue of abstraction principles, an issue that has been broadly discussed during the last decades with regard to the Neo-Fregean program. This paper aims to show off the way Weyl's account of abstraction could offer a reply to Benacerraf's (1973) challenge to realism. Benacerraf argued that mathematical realism is not associated with a plausible epistemology about human access to abstract objects. Weyl deals with the method of abstraction by investigating certain cases of Fregean abstraction principles. He thinks that we can introduce shapes of geometrical images, integers mod m, circles, directions of lines etc. by means of certain creative acts of consciousness, especially intentionality towards proper relations between the elements of an initial domain. Weyl puts emphasis on intentions towards certain invariant characteristics of items that are involved in equivalence relations. Further, he claims that those invariants are transformed into ideal objects through a finite process that is involved in intuition. This paper, in the first place, attempts to make explicit Weyl's phenomenological leanings. Secondly, it argues that Weyl's explanation of how ideal mathematical objects become present to mind can address the epistemic issue concerning mathematical knowledge and can also be associated with a particular view which is implicit in his philosophy and retains realistic elements. Hence, it can address Benacerraf's problem. 展开更多
关键词 abstraction equivalence relation INTENTIONALITY invariant INTUITION ideal object knowledge
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Generalized Szasz Problems in Normal Classes of Algebras
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作者 王尧 牛凤文 《Northeastern Mathematical Journal》 CSCD 2004年第2期225-235,共11页
Let A be a normal class of algebras. In the present paper, we characterize the following four problems for A: for which radical class R, there holds that(1) R(i1∧i2) = R(i1)∧R(i2);(2) R(i1∨i2) = R(i1)∨R(i2);(3) (i... Let A be a normal class of algebras. In the present paper, we characterize the following four problems for A: for which radical class R, there holds that(1) R(i1∧i2) = R(i1)∧R(i2);(2) R(i1∨i2) = R(i1)∨R(i2);(3) (i1∧i2) =i1∧i2;(4) (i1∨i2) = i1∨i2, for arbitrary algebra a∈A and any i1,i2∈La,where j denotes the ideal of a uniquely determined by R(a/j) = j/j? 展开更多
关键词 normal class of algebra LATTICE equivalence relation RADICAL
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On C^(*)-algebras from homoclinic equivalences on subshifts of finite type
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作者 Chengjun Hou 《Science China Mathematics》 SCIE CSCD 2021年第4期747-762,共16页
Let G be an infinite countable group and A be a finite set.IfΣ?A~G is a strongly irreducible subshift of finite type,we endow a locally compact and Hausdorff topology on the homoclinic equivalence relation■onΣand s... Let G be an infinite countable group and A be a finite set.IfΣ?A~G is a strongly irreducible subshift of finite type,we endow a locally compact and Hausdorff topology on the homoclinic equivalence relation■onΣand show that the reduced C^(*)-algebra C_(r)^(*)(■)of■is a unital simple approximately finite(AF)-dimensional C^(*)-algebra.The shift action G of onΣinduces a canonical automorphism action of G on the C^(*)-algebra C_(r)^(*)(■).We give the notion of noncommutative dynamical entropy invariants for amenable group actions on C^(*)-algebras,and show that,if G is an amenable group,then the noncommutative topological entropy of the canonical automorphism action of G on C_(r)^(*)(■)is equal to the topology entropy of the shift action of G onΣ.We also establish the variational principle with respect to the noncommutative measure entropy and the topological entropy for the C^(*)-dynamical system(C_(r)^(*)(■),G). 展开更多
关键词 homoclinic equivalence relation groupoid C^(*)-algebra amenable group action entropy
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Relative Derived Equivalences and Relative Homological Dimensions
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作者 Sheng Yong PAN 《Acta Mathematica Sinica,English Series》 SCIE CSCD 2016年第4期439-456,共18页
Let A be a small abelian category.For a closed subbifunctor F of Ext_A^1(-,-),Buan has generalized the construction of Verdier’s quotient category to get a relative derived category,where he localized with respect ... Let A be a small abelian category.For a closed subbifunctor F of Ext_A^1(-,-),Buan has generalized the construction of Verdier’s quotient category to get a relative derived category,where he localized with respect to F-acyclic complexes.In this paper,the homological properties of relative derived categories are discussed,and the relation with derived categories is given.For Artin algebras,using relative derived categories,we give a relative version on derived equivalences induced by F-tilting complexes.We discuss the relationships between relative homological dimensions and relative derived equivalences. 展开更多
关键词 Relative derived category F-tilting complex relative derived equivalence relative homological dimension
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Hierarchical Covering Algorithm 被引量:1
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作者 Jie Chen Shu Zhao Yanping Zhang 《Tsinghua Science and Technology》 SCIE EI CAS 2014年第1期76-81,共6页
The concept of deep learning has been applied to many domains, but the definition of a suitable problem depth has not been sufficiently explored. In this study, we propose a new Hierarchical Covering Algorithm (HCA)... The concept of deep learning has been applied to many domains, but the definition of a suitable problem depth has not been sufficiently explored. In this study, we propose a new Hierarchical Covering Algorithm (HCA) method to determine the levels of a hierarchical structure based on the Covering Algorithm (CA). The CA constructs neural networks based on samples' own characteristics, and can effectively handle multi-category classification and large-scale data. Further, we abstract characters based on the CA to automatically embody the feature of a deep structure. We apply CA to construct hidden nodes at the lower level, and define a fuzzy equivalence relation R on upper spaces to form a hierarchical architecture based on fuzzy quotient space theory. The covering tree naturally becomes from R. HCA experiments performed on MNIST dataset show that the covering tree embodies the deep architecture of the problem, and the effects of a deep structure are shown to be better than having a single level. 展开更多
关键词 deep architecture HIERARCHY fuzzy equivalence relation covering tree MNIST dataset
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