Results 21 to 30 of about 4,003 (147)

Matroidal Structure of Rough Sets Based on Serial and Transitive Relations

open access: yesJournal of Applied Mathematics, 2012
The theory of rough sets is concerned with the lower and upper approximations of objects through a binary relation on a universe. It has been applied to machine learning, knowledge discovery, and data mining. The theory of matroids is a generalization of
Yanfang Liu, William Zhu
doaj   +1 more source

Matroid toric ideals: complete intersection, minors and minimal systems of generators [PDF]

open access: yes, 2015
In this paper, we investigate three problems concerning the toric ideal associated to a matroid. Firstly, we list all matroids $\mathcal M$ such that its corresponding toric ideal $I_{\mathcal M}$ is a complete intersection.
Alfonsín, Jorge Luis Ramírez   +1 more
core   +2 more sources

Nullity and Loop Complementation for Delta-Matroids [PDF]

open access: yes, 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

The highly connected even-cycle and even-cut matroids [PDF]

open access: yes, 2018
The classes of even-cycle matroids, even-cycle matroids with a blocking pair, and even-cut matroids each have hundreds of excluded minors. We show that the number of excluded minors for these classes can be drastically reduced if we consider in each ...
Grace, Kevin, van Zwam, Stefan H. M.
core   +3 more sources

Short Cocircuits in Binary Matroids

open access: yesEuropean Journal of Combinatorics, 1987
The authors' summary: ``Given a simple graph G having vertex set V, it is obvious that for any spanning tree T, there is an edge of T whose fundamental cutset has size at most \(| V| -1\). We extend this result to matroids. Call a cocircuit of a matroid M short if its size is at most the rank of M.
Bixby, Robert E., Cunningham, William H.
openaire   +1 more source

An extended formulation for the 1‐wheel inequalities of the stable set polytope

open access: yesNetworks, Volume 75, Issue 1, Page 86-94, January 2020., 2020
Abstract The 1‐wheel inequalities for the stable set polytope were introduced by Cheng and Cunningham. In general, there is an exponential number of these inequalities. We present a new polynomial size extended formulation of the stable set relaxation that includes the odd cycle and 1‐wheel inequalities.
Sven de Vries   +2 more
wiley   +1 more source

Complementation, Local Complementation, and Switching in Binary Matroids [PDF]

open access: yes, 2020
In 2004, Ehrenfeucht, Harju, and Rozenberg showed that any graph on a vertex set $V$ can be obtained from a complete graph on $V$ via a sequence of the operations of complementation, switching edges and non-edges at a vertex, and local complementation ...
Oxley, James, Singh, Jagdeep
core   +3 more sources

Matroid union — Graphic? Binary? Neither?

open access: yesDiscrete Applied Mathematics, 2016
zbMATH Open Web Interface contents unavailable due to conflicting licenses.
Csehi, Csongor György, Recski, András
openaire   +3 more sources

The moduli space of matroids [PDF]

open access: yes, 2018
In the first part of the paper, we clarify the connections between several algebraic objects appearing in matroid theory: both partial fields and hyperfields are fuzzy rings, fuzzy rings are tracts, and these relations are compatible with the respective ...
Baker, Matthew, Lorscheid, Oliver
core   +2 more sources

Connected Hyperplanes in Binary Matroids

open access: yesJournal of Combinatorial Theory, Series B, 2000
zbMATH Open Web Interface contents unavailable due to conflicting licenses.
McNulty, Jennifer, Wu, Haidong
openaire   +2 more sources

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