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Toda谱V(1)的自映射群
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作者 林金坤 《南开大学学报(自然科学版)》 CAS CSCD 北大核心 1999年第3期17-20,共4页
本文给出了由Toda 谱V(1)的同伦群πV(1)确定出它的自映射群[ΣV(1),V(1)]的一般方法,并且由πV(1)的已知结果确定了[ΣV(1),V(1)]在次数< 2(p2 + 2p)(p- 1)- 5 时的... 本文给出了由Toda 谱V(1)的同伦群πV(1)确定出它的自映射群[ΣV(1),V(1)]的一般方法,并且由πV(1)的已知结果确定了[ΣV(1),V(1)]在次数< 2(p2 + 2p)(p- 1)- 5 时的全部Zp 基元,其中p≥5 展开更多
关键词 Toda谱 自映射群 ADAMS谱序列 上纤维
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Turnout fault diagnosis based on DBSCAN/PSO-SOM 被引量:3
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作者 YANG Juhua LI Xutong +1 位作者 XING Dongfeng CHEN Guangwu 《Journal of Measurement Science and Instrumentation》 CAS CSCD 2022年第3期371-378,共8页
In order to diagnose the common faults of railway switch control circuit,a fault diagnosis method based on density-based spatial clustering of applications with noise(DBSCAN)and self-organizing feature map(SOM)is prop... In order to diagnose the common faults of railway switch control circuit,a fault diagnosis method based on density-based spatial clustering of applications with noise(DBSCAN)and self-organizing feature map(SOM)is proposed.Firstly,the three-phase current curve of the switch machine recorded by the micro-computer monitoring system is dealt with segmentally and then the feature parameters of the three-phase current are calculated according to the action principle of the switch machine.Due to the high dimension of initial features,the DBSCAN algorithm is used to separate the sensitive features of fault diagnosis and construct the diagnostic sensitive feature set.Then,the particle swarm optimization(PSO)algorithm is used to adjust the weight of SOM network to modify the rules to avoid“dead neurons”.Finally,the PSO-SOM network fault classifier is designed to complete the classification and diagnosis of the samples to be tested.The experimental results show that this method can judge the fault mode of switch control circuit with less training samples,and the accuracy of fault diagnosis is higher than that of traditional SOM network. 展开更多
关键词 TURNOUT fault diagnosis density-based spatial clustering of applications with noise(DBSCAN) particle swarm optimization(PSO) self-organizing feature map(SOM)
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When a smooth self-map of a semi-simple Lie group can realize the least number of periodic points
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作者 JEZIERSKI Jerzy 《Science China Mathematics》 SCIE CSCD 2017年第9期1579-1590,共12页
There are two algebraic lower bounds of the number of n-periodic points of a self-map f : M →4 M of a compact smooth manifold of dimension at least 3: NFn(f) = min{#Fix(gn);g - f; g continuous} and NJDn(f) = ... There are two algebraic lower bounds of the number of n-periodic points of a self-map f : M →4 M of a compact smooth manifold of dimension at least 3: NFn(f) = min{#Fix(gn);g - f; g continuous} and NJDn(f) = min{#Fix(gn);g - f; g smooth}. In general, NJDn(f) may be much greater than NFn(f). We show that for a self-map of a semi-simple Lie group, inducing the identity fundamental group homomorphism, the equality NFn(f) = NJDn(f) holds for all n →← all eigenvalues of a quotient cohomology homomorphism induced by f have moduli ≤ 1. 展开更多
关键词 periodic points Nielsen number fixed point index smooth maps Lie group
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THE TRACE SPACE INVARIANT AND UNITARY GROUP OF C-ALGEBRA
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作者 FANG XIAOCHUN 《Chinese Annals of Mathematics,Series B》 SCIE CSCD 2003年第1期115-122,共8页
Let A be a unital C-algebra, n ∈ N ∪ {∞}. It is proved that the isomorphism △n : is isometric for some suitable distances. Asan application, the author has the split exact sequence with iA contractive (and isometr... Let A be a unital C-algebra, n ∈ N ∪ {∞}. It is proved that the isomorphism △n : is isometric for some suitable distances. Asan application, the author has the split exact sequence with iA contractive (and isometric if n = ∞) under certain condition of A. 展开更多
关键词 Trace space Unitary group C-ALGEBRA
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