Results 51 to 60 of about 70,377,857 (147)
, 2017 Digital convex (DC) sets plays a prominent role in the framework of digital geometry providing a natural generalization to the concept of Euclidean convexity when we are dealing with polyominoes, i.e., finite and connected sets of points.
Lama Tarsissi +14 more
core +1 more source
Finite-Repetition threshold for infinite ternary words [PDF]
Electronic Proceedings in Theoretical Computer Science, 2011 The exponent of a word is the ratio of its length over its smallest period. The repetitive threshold r(a) of an a-letter alphabet is the smallest rational number for which there exists an infinite word whose finite factors have exponent at most r(a ...
Golnaz Badkobeh, Maxime Crochemore
doaj +1 more source
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
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 +4 more
core +1 more source
Some combinatorics of rhomboid-shaped fully packed loop configurations [PDF]
Discrete Mathematics & Theoretical Computer Science, 2014 The study of rhomboid-shaped fully packed loop configurations (RFPLs) is inspired by the work of Fischer and Nadeau on triangular fully packed loop configurations (TFPLs).
Sabine Beil
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
Directive words of episturmian words: equivalences and normalization [PDF]
, 2008 Episturmian morphisms constitute a powerful tool to study episturmian words. Indeed, any episturmian word can be infinitely decomposed over the set of pure episturmian morphisms.
Amy Glen +8 more
core +1 more source
Classifying Equidistant Permutation Codes
Journal of Combinatorial Designs, EarlyView.ABSTRACT A permutation code of length n $n$ is a set of codewords, each of which contains every symbol of a set of size n $n$ exactly once. A permutation code in which any two distinct codewords differ in the same number of coordinates is called equidistant and that number is called the distance.
Patric R. J. Östergård +1 more
wiley +1 more source
Obstructions for Homomorphisms to Odd Cycles in Series‐Parallel Graphs
Journal of Graph Theory, EarlyView.ABSTRACT For a graph H $H$, an H $H$‐colouring of a graph G $G$ is a vertex mapping ϕ : V ( G ) → V ( H ) $\phi :V(G)\to V(H)$ such that adjacent vertices are mapped to adjacent vertices. A graph G $G$ is C 2 k + 1 ${C}_{2k+1}$‐critical if G $G$ has no C 2 k + 1 ${C}_{2k+1}$‐colouring but every proper subgraph of G $G$ has a C 2 k + 1 ${C}_{2k+1 ...
Eun‐Kyung Cho +3 more
wiley +1 more source
Random multilinear maps and the Erdős box problem
Discrete Analysis, 2021 Random multilinear maps and the Erdős box problem, Discrete Analysis 2021:17, 8 pp. A major theme in extremal combinatorics is determining the maximum number of edges that a graph or hypergraph can have if it does not contain a certain fixed graph or ...
David Conlon +2 more
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