Results 41 to 50 of about 48,688 (228)
Subsquares in Random Latin Squares and Rectangles
Journal of Combinatorial Designs, EarlyView.ABSTRACT A k×n $k\times n$ partial Latin rectangle is C‐sparse $C \mbox{-} \mathrm{sparse}$ if the number of nonempty entries in each row and column is at most C $C$ and each symbol is used at most C $C$ times. We prove that the probability a uniformly random k×n $k\times n$ Latin rectangle, where k<(1∕2−α)n $k\lt (1\unicode{x02215}2-\alpha )n ...
Alexander Divoux +3 more
wiley +1 more source
The maximal spectral radius of a digraph with (m+1)^2 - s edges
, 2003 It is known that the spectral radius of a digraph with k edges is \le \sqrt{k}, and that this inequality is strict except when k is a perfect square. For k=m^2 + \ell, \ell fixed, m large, Friedland showed that the optimal digraph is obtained from the ...
Snellman, Jan
core +1 more source
H-kernels by walks in H-colored digraphs and the color-class digraph
AKCE International Journal of Graphs and Combinatorics, 2016 Let H be a digraph possibly with loops and D a finite digraph without loops whose arcs are colored with the vertices of H (D is an H-colored digraph). V(D) and A(D) will denote the sets of vertices and arcs of D respectively.
Hortensia Galeana-Sánchez +1 more
doaj +1 more source
Graph partitioning: an updated survey
AKCE International Journal of Graphs and Combinatorics, 2023 Graph partitioning problem, which is one of the most important topics in graph theory, usually asks for a partition of the vertex set of a graph into pairwise disjoint subsets with various requirements. It comes from the well-known Max-Cut Problem: Given
Shufei Wu, Jianfeng Hou
doaj +1 more source
Perfect Matching Under Precedence Constraints
Networks, EarlyView.ABSTRACT In this article, we motivate and define variants of perfect matching under precedence constraints where a perfect matching is built incrementally and precedence constraints ensure that an edge may only be added to the matching if the edge's predecessor vertices have already been covered.
Christina Büsing, Corinna Mathwieser
wiley +1 more source
On (4,2)-digraph Containing a Cycle of Length 2 [PDF]
, 2000 A diregular digraph is a digraph with the in-degree and out-degree of all vertices is constant. The Moore bound for a diregular digraph of degree d and diameter k is M_{d,k}=l+d+d^2+...+d^k.
Baskoro, Edy Tri, Iswadi, Hazrul
core
Toward Wojda's conjecture on digraph packing [PDF]
Opuscula Mathematica, 2017 Given a positive integer \(m\leq n/2\), Wojda conjectured in 1985 that if \(D_1\) and \(D_2\) are digraphs of order \(n\) such that \(|A(D_1)|\leq n-m\) and \(|A(D_2)|\leq 2n-\lfloor n/m\rfloor-1\) then \(D_1\) and \(D_2\) pack.
Jerzy Konarski, Andrzej Żak
doaj +1 more source
Block digraph of a directed graph
Open Journal of Mathematical Sciences, 2018 Let D be a connected digraph of order n (n ≥ 3) and let B(D) = {B1, B2, . . . , BN} be a set of blocks of D. The block digraph Q = B(D) has vertex set V (Q) = B(D) and arc set A(Q) = BiBj : Bi, Bj ∈ V (Q), Bi, Bj have a cut-vertex of D in common and ...
H. M. Nagesh +2 more
semanticscholar +1 more source
Networks, EarlyView.ABSTRACT This work considers branch‐price‐and‐cut algorithms for variants of the vehicle‐routing problem in which subset‐row inequalities (SRIs) are used to strengthen the linear relaxation. SRIs often help to substantially reduce the size of the branch‐and‐bound search tree.
Stefan Faldum +2 more
wiley +1 more source
Teaching Reading as a Complex and Multidimensional Process
The Reading Teacher, Volume 79, Issue 5, March/April 2026.ABSTRACT This article examines the teaching of reading as a complex and multidimensional process amidst current approaches to teaching reading forwarded by new legislation and curricula that have been adopted across the United States. We underscore the importance of a comprehensive understanding of the teaching of early reading by bringing together ...
Faythe Beauchemin +3 more
wiley +1 more source