Results 51 to 60 of about 37,501 (244)
On the combinatorics of sparsification [PDF]
Algorithms for Molecular Biology, 2012 Background: We study the sparsification of dynamic programming folding algorithms of RNA structures. Sparsification applies to the mfe-folding of RNA structures and can lead to a significant reduction of time complexity. Results: We analyze the sparsification of a particular decomposition rule, $Λ^*$, that splits an interval for RNA secondary and ...
Huang, Fenix Wenda, reidys, Christian
openaire +7 more sources
Exact Values and Bounds on Covering Schemes of Strength Two
Journal of Combinatorial Designs, EarlyView.ABSTRACT In this work, we investigate covering schemes of strength 2 over finite abelian groups, establishing new lower and upper bounds and evaluating new exact values. A main result is a new general lower bound that improves the trivial one and achieves optimality for the binary case. We also develop a recursive relation based on subsets of the group
André G. Castoldi +4 more
wiley +1 more source
Generalized Rainbow Connection of Graphs and their Complements
Discussiones Mathematicae Graph Theory, 2018 Let G be an edge-colored connected graph. A path P in G is called ℓ-rainbow if each subpath of length at most ℓ + 1 is rainbow. The graph G is called (k, ℓ)-rainbow connected if there is an edge-coloring such that every pair of distinct vertices of G is ...
Li Xueliang +3 more
doaj +1 more source
Partial Steiner Triple Systems With an Almost Parallel Class Missing Any Given Point
Journal of Combinatorial Designs, EarlyView.ABSTRACT We say that a hypergraph is factor critical if it has no 1‐factor but deletion of any vertex results in a hypergraph that has a 1‐factor. We show that any factor‐critical hypergraph of order n $n$ has at least n $n$ edges, and that for all integers k > 1 $k\gt 1$ and n > 1 $n\gt 1$ with n ≡ 1 ( mod k ) $n\equiv 1({\rm{mod}}\,k)$ there exists a
Darryn Bryant +2 more
wiley +1 more source
On the conjunctive capacity of graphs [PDF]
, 2013 The investigation of the asymptotic behaviour of various graph parameters in powers of a fixed graph G=(V,E) is motivated by problems in information theory and extremal ...
Chlebikova, Janka +5 more
core +1 more source
Compatible cycles and CHY integrals
Journal of High Energy Physics, 2019 The CHY construction naturally associates a vector in ℝ(n−3)! to every 2- regular graph with n vertices. Partial amplitudes in the biadjoint scalar theory are given by the inner product of vectors associated with a pair of cycles.
Freddy Cachazo +2 more
doaj +1 more source
Catalan Bounds for Symmetric Strength‐Two Orthogonal Arrays
Journal of Combinatorial Designs, EarlyView.ABSTRACT A Hamming shell construction is a two‐level array obtained by taking every binary vector of a given Hamming weight a prescribed number of times, for each weight in turn. Such arrays are invariant under all permutations of the factors, and they are strength‐two orthogonal arrays exactly when the multiplicities satisfy three linear constraints ...
Ruwan C. Karunanayaka
wiley +1 more source
Induced subarrays of Latin squares without repeated symbols [PDF]
, 2013 We show that for any Latin square L of order 2m, we can partition the rows and columns of L into pairs so that at most (m+3)/2 of the 2x2 subarrays induced contain a repeated symbol.
Kuhl, Jaromy +2 more
core
Absorptions in combinatorics [PDF]
This thesis mainly focuses on the following transversal problem, which is closely related to the absorption technique in extremal combinatorics: Given a collection of simple graphs G1, . . . , Gt defined on the same vertex set V, where each graph Gi (1 ≤
Cheng, Yangyang
core +1 more source
Enumeration of Gelfand-Cetlin type reduced words
, 2022 The combinatorics of reduced words and their commutation classes plays an important role in geometric representation theory. For a semisimple complex Lie group G, a string polytope is a convex polytope associated with each reduced word of the longest ...
Kim, Jang Soo +2 more
core +1 more source