Results 31 to 40 of about 14,016 (208)
Factorization theorems for strong maps between matroids of arbitrary cardinality
Open Mathematics, 2016 In this paper we present factorization theorems for strong maps between matroids of arbitrary cardinality. Moreover, we present a new way to prove the factorization theorem for strong maps between finite matroids.
Mao Hua
doaj +1 more source
A Note on Ultrametric Spaces, Minimum Spanning Trees and the Topological Distance Algorithm
Information, 2020 We relate the definition of an ultrametric space to the topological distance algorithm—an algorithm defined in the context of peer-to-peer network applications.
Jörg Schäfer
doaj +1 more source
The Electronic Journal of Combinatorics, 2006 One way to choose a basis of a matroid at random is to choose an ordering of the ground set uniformly at random and then use the greedy algorithm to find a basis. We investigate the class of matroids having the property that this procedure yields a basis uniformly at random.
openaire +2 more sources
Invariants of vector configurations [PDF]
Discrete Mathematics & Theoretical Computer Science, 2012 We investigate the Zariski closure of the projective equivalence class of a matrix. New results are presented regarding the matrices in this variety and their matroids, and we give equations for the variety.
Andrew Berget, Alex Fink
doaj +1 more source
Nullity and Loop Complementation for Delta-Matroids [PDF]
, 2012 We show that the symmetric difference distance measure for set systems, and more specifically for delta-matroids, corresponds to the notion of nullity for symmetric and skew-symmetric matrices. In particular, as graphs (i.e., symmetric matrices over GF(2)
Bouchet A. +6 more
core +1 more source
Combinatorics of Positroids [PDF]
Discrete Mathematics & Theoretical Computer Science, 2009 Recently Postnikov gave a combinatorial description of the cells in a totally-nonnegative Grassmannian. These cells correspond to a special class of matroids called positroids.
Suho Oh
doaj +1 more source
Matroidal Structure of Rough Sets from the Viewpoint of Graph Theory
Journal of Applied Mathematics, 2012 Constructing structures with other mathematical theories is an important research field of rough sets. As one mathematical theory on sets, matroids possess a sophisticated structure.
Jianguo Tang, Kun She, William Zhu
doaj +1 more source
, 2012 In this paper, we propose a new type of matroids, namely covering matroids, and investigate the connections with the second type of covering-based rough sets and some existing special matroids.
Liu, Yanfang, Zhu, William
core
, 2013 We investigate the computational difficulty of approximating the partition function of the ferromagnetic Ising model on a regular matroid. Jerrum and Sinclair have shown that there is a fully polynomial randomised approximation scheme (FPRAS) for the ...
Goldberg, Leslie Ann, Jerrum, Mark
core +1 more source
Nonlinear Matroid Optimization and Experimental Design [PDF]
, 2007 We study the problem of optimizing nonlinear objective functions over matroids presented by oracles or explicitly. Such functions can be interpreted as the balancing of multi-criteria optimization. We provide a combinatorial polynomial time algorithm for
Eva Riccomagno +7 more
core +7 more sources