Results 201 to 210 of about 791,112 (289)

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, Anderson N. Martinhão, Emerson L. Monte Carmelo, Pablo H. Perondi, Otávio J. N. T. N. dos Santos   +4 more
wiley   +1 more source

A MacMahon analysis view of cylindric partitions. [PDF]

Ramanujan J
Li R, Uncu AK.
europepmc   +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, Sara Davies, Jack Neubecker   +2 more
wiley   +1 more source

Some New Maximally Chaotic Discrete Maps. [PDF]

Entropy (Basel)
Choi H, Kim G, Song HY, Shin S, Lee C, Noh H.   +5 more
europepmc   +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

Density Conditions for k $k$ Vertex‐Disjoint Triangles in Tripartite Graphs

Journal of Graph Theory, EarlyView.
ABSTRACT Let n , k $n,k$ be positive integers such that n ≥ k $n\ge k$ and G $G$ be a tripartite graph with parts A , B , C $A,B,C$ such that ∣ A ∣ = ∣ B ∣ = ∣ C ∣ = n $| A| =| B| =| C| =n$. Denote the edge densities of G [ A , B ] , G [ A , C ] $G[A,B],G[A,C]$ and G [ B , C ] $G[B,C]$ by α , β $\alpha ,\beta $ and γ $\gamma $, respectively.
Mingyang Guo, Klas Markström
wiley   +1 more source

Analogs of the Prime Number Problem in a Shot Noise Suppression of the Soft-Reset Process. [PDF]

Nanomaterials (Basel)
Hirose Y.
europepmc   +1 more source

On Fork‐Free t‐Perfect Graphs

Journal of Graph Theory, EarlyView.
ABSTRACT In an effort to understand the complexity of the maximum independent set problem, Chvátal introduced t‐perfect graphs. While a full characterization of this class remains open, important progress has been made for claw‐free graphs [Bruhn and Stein, Math. Program. 2012] and P 5 ${P}_{5}$‐free graphs [Bruhn and Fuchs, SIAM J. Discrete Math. 2017]
Yixin Cao, Shenghua Wang
wiley   +1 more source

Exploring new lengths for q-ary quantum MDS codes with larger distance. [PDF]

PLoS One
He X, Wang J, Huang C, Chen Y.
europepmc   +1 more source

Chromatic Ramsey Numbers and Two‐Color Turán Densities

Journal of Graph Theory, EarlyView.
ABSTRACT Given a graph G, its 2‐color Turán number ex ( 2 ) ( n , G ) is the maximum number of edges in an n‐vertex graph, such that the edges can be colored with two colors avoiding a monochromatic copy of G. Let π ( 2 ) ( G ) = lim n → ∞ ex ( 2 ) ( n , G ) / n 2 be the 2‐color Turán density of G.
Maria Axenovich, Simon Gaa, Dingyuan Liu
wiley   +1 more source