Results 271 to 280 of about 51,609 (309)

A Z2-topological index as a Z2-state index

Journal of Mathematical Physics, 2022
Within the setting of infinite-dimensional self-dual CAR C* algebras describing fermions in the Zd lattice, we depart from the well-known Araki–Evans σ(P1,P2)Z2 index for quasi-free fermion states and rewrite it in terms of states rather than in terms of basis projections.
N. J. B. Aza, L. C. P. A. M. Müssnich, A. F. Reyes-Lega   +2 more
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An index of topological preservation for feature extraction

Pattern Recognition, 1995
Abstract This paper is about the ability of principal components analysis, the Sammon algorithm, and an extension of the Kohonen self-organizing feature map to preserve spatial order during feature extraction on unlabeled data. Transformations to q -space that preserve the order of all pairwise distances in any set of vectors in p -space are ...
James C. Bezdek, Nikhil R. Pal
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On Highly Discriminating Molecular Topological Index

Journal of Chemical Information and Computer Sciences, 1996
A highly discriminating molecular topological index, EAID, is proposed based on the extended adjacency matrix. A systematic search for degeneracy was performed for 3 807 434 alkane trees, 202 558 complex cyclic or polycyclic graphs, and 430 472 structures containing heteroatoms.
Chang-Yu Hu, Lu Xu
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Extension of a Highly Discriminating Topological Index

Journal of Chemical Information and Modeling, 2015
A highly discriminating topological index, EAID, is generated in our laboratory. A systematic search for degeneracy was performed on a total of over 14 million structures, and no duplicate occurred. These structures are as follows: over 3.8 million alkane trees with 1-22 carbon atoms; over 0.38 million structures containing heteroatoms; over 4 million ...
Qing-You Zhang, Chengcheng Wu, Fangfang Zheng, Tanfeng Zhao, Yanmei Zhou, Lu Xu   +5 more
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On the forgotten topological index

2017
Summary: The forgotten topological index of a graph \(G\) is defined as \(F(G)=\sum_{u\in V(G)}d(u)^3\). In this paper, we compute some properties of forgotten index and then, we determine it for some classes of product graphs.
Ghorbani, M., Khaksari, A.
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The Sum of a Topological Index and Its Reciprocal Index

Match Communications in Mathematical and in Computer Chemistry
Summary: Let \(G\) be a simple connected graph. For a vertex-degree-based topological index \(TI_f(G) = \sum\limits_{uv\in E(G)}f(d_u, d_v)\), where \(f(x, y)\) is a pertinently chosen symmetric real function, the topological index \(RTI_f(G) = \sum\limits_{uv\in E(G)}\frac{1}{f(d_u, d_v)}\) is called the reciprocal index of \(TI_f\).
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A New Topological Index for QSPR of Alkanes

Journal of Chemical Information and Computer Sciences, 1998
A new topological index Xu based on the adjacency matrix A and the distance matrix D is derived in this paper. The index, which is very simple to calculate and also has good discrimination of alkane isomers, is used to correlate with the selected physicochemical properties of a wide range of alkanes.
openaire   +1 more source

Topological Index and Analytical Index: Reformulation of Index Theory

2019
In this part we present the main algebraic structures on topological manifolds and we reformulate the index theory.
openaire   +1 more source

Molecular topological index: a relation with the Wiener index

Journal of Chemical Information and Computer Sciences, 1992
Douglas J. Klein, Zlatko Mihalic, Dejan Plavsic, Nenad Trinajstic   +3 more
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Computation of the Forgotten Topological Index and Co-Index for Carbon Base Nanomaterial

Polycyclic Aromatic Compounds, 2022
Özge Colakoglu Havare, Ali Kemal Havare
exaly