Results 41 to 50 of about 16,499 (231)

On arc-coloring of digraphs [PDF]

Opuscula Mathematica, 2006
In the paper we deal with the problem of the arc-colouring of some classes of digraphs (tournaments, complete digraphs and products of digraphs).
Małgorzata Zwonek
doaj  

More skew-equienergetic digraphs

Communications in Combinatorics and Optimization, 2016
Two digraphs of same order are said to be skew-equienergetic if their skew energies are equal‎. ‎One of the open problems proposed by Li and Lian was to construct non-cospectral skew-equienergetic digraphs on n vertices‎.
Ch‎. ‎Adiga, B‎. ‎R‎. ‎Rakshith   +1 more
doaj   +1 more source

k-Majority Digraphs and the Hardness of Voting with a Constant Number of Voters [PDF]

Journal of computer and system sciences (Print), 2017
Many hardness results in computational social choice make use of the fact that every directed graph may be induced as the pairwise majority relation of some preference profile.
Georg Bachmeier, F. Brandt, Christian Geist, Paul Harrenstein, Keyvan Kardel, Dominik Peters, Hans Georg Seedig   +6 more
semanticscholar   +1 more source

Xk-Digraphs

Journal of Combinatorial Theory, Series B, 1981
AbstractLet G be a directed graph on n vertices (single loops allowed) such that there are λ directed paths of length k from P to Q for any distinct pair of vertices (P, Q). We prove that if n > 2 and k > 2, G is regular. The regular case is also discussed.
William G. Bridges, R. A. Mena
openaire   +2 more sources

Study of Cayley Digraphs over Polygroups

Mathematics
In this paper we introduce Cayley digraphs associated to finitely generated polygroups, where the vertices correspond to finite products of the generators of polygroups and the edges to multiplication by vertices and generators.
Ali Sanjabi, Morteza Jafarpour, Sarka Hoskova-Mayerova, Hossien Aghabozorgi, Alena Vagaska   +4 more
doaj   +1 more source

On Decomposing the Complete Symmetric Digraph into Orientations of K4 − e

Discussiones Mathematicae Graph Theory, 2019
Let D be any of the 10 digraphs obtained by orienting the edges of K4 − e. We establish necessary and sufficient conditions for the existence of a (Kn*$K_n^*$, D)-design for 8 of these digraphs.
Bunge Ryan C., Darrow Brian D., Dubczuk Toni M., El-Zanati Saad I., Hao Hanson H., Keller Gregory L., Newkirk Genevieve A., Roberts Dan P.   +7 more
doaj   +1 more source

Decision-Making Approach Based on Neutrosophic Rough Information

Algorithms, 2018
Rough set theory and neutrosophic set theory are mathematical models to deal with incomplete and vague information. These two theories can be combined into a framework for modeling and processing incomplete information in information systems.
Muhammad Akram, Nabeela Ishfaq, Sidra Sayed, Florentin Smarandache   +3 more
doaj   +1 more source

Efficient Open Domination in Digraph Products

Mathematics, 2020
A digraph D is an efficient open domination digraph if there exists a subset S of V ( D ) for which the open out-neighborhoods centered in the vertices of S form a partition of V ( D ) .
Dragana Božović, Iztok Peterin
doaj   +1 more source

Path homologies of motifs and temporal network representations

Applied Network Science, 2022
Path homology is a powerful method for attaching algebraic invariants to digraphs. While there have been growing theoretical developments on the algebro-topological framework surrounding path homology, bona fide applications to the study of complex ...
Samir Chowdhury, Steve Huntsman, Matvey Yutin   +2 more
doaj   +1 more source

The A spectral radius characterization of some digraphs

Linear Algebra and its Applications, 2019
Let λ ( D ) be the A α spectral radius of digraph D, and let G n r be the set of digraphs with order n and dichromatic number r. In this paper, we characterize the digraph which has the maximal A α spectral radius in G n r .
Jianping Liu, Xianzhang Wu, Jinsong Chen, Bolian Liu   +3 more
semanticscholar   +1 more source