搜索结果: 151-165 共查到“知识库 组合数学”相关记录451条 . 查询时间(1.763 秒)
Classification of nonorientable regular embeddings of Hamming graphs
Graph embeddings regular embeddings regular map Hamming graphs
2011/9/9
Abstract: By a regular embedding of a graph K in a surface we mean a 2-cell embedding of K in a compact connected surface such that the automorphism group acts regularly on flags. In this paper, we cl...
Discrete Morse theory and the consecutive pattern poset
consecutive pattern discrete Morse theory factor order Mobius function permutation patters posets
2011/9/13
Abstract: We use discrete Morse theory to provide another proof of Bernini, Ferrari, and Steingrimson's formula for the Mobius function of the consecutive pattern poset. In addition, we are able to de...
The set of autotopisms of partial Latin squares
Partial Latin square autotopism group cycle structure
2011/9/13
Abstract: Symmetries of a partial Latin square are determined by its autotopism group. Analogously to the case of Latin squares, given an isotopism $\Theta$, the cardinality of the set $\mathcal{PLS}_...
Arrow ribbon graphs
Graphs on surfaces ribbon graphs Bollobas-Riordan polynomial Tutte polynomial duality virtual links arrow polynomial
2011/9/13
Abstract: We introduce an additional structure on ribbon graphs, arrow structure. We extend the Bollob\'as-Riordan polynomial to ribbon graph with this structure. The extended polynomial satisfies the...
An Erdos-Ko-Rado theorem in general linear groups
Erdos-Ko-Rado theorem general linear group Combinatorics
2011/9/9
Abstract: Let $S_n$ be the symmetric group on $n$ points. Deza and Frankl [M. Deza and P. Frankl, On the maximum number of permutations with given maximal or minimal distance, J. Combin. Theory Ser. A...
The Expected Order of Saturated RNA Secondary Structures
Horton-Strahler number generating function Hankel contour Transfer Theorem singularity analysis
2011/9/9
Abstract: We show the expected order of RNA saturated secondary structures of size $n$ is $\log_4n(1+O(\frac{\log_2n}{n}))$, if we select the saturated secondary structure uniformly at random. Further...
Monochromatic 4-term arithmetic progressions in 2-colorings of $\mathbb Z_n$
Monochromatic 4-term arithmetic progressions Combinatorics Number Theory
2011/9/8
Abstract: This paper is motivated by a recent result of Wolf \cite{wolf} on the minimum number of monochromatic 4-term arithmetic progressions(4-APs, for short) in $\Z_p$, where $p$ is a prime number....
The disentangling number for phylogenetic mixtures
disentangling number phylogenetic mixtures Combinatorics
2011/9/8
Abstract: We provide a logarithmic upper bound for the disentangling number on unordered lists of leaf labeled trees. This results is useful for analyzing phylogenetic mixture models. The proof depend...
Abstract: Felsner and Reuter introduced the linear extension diameter of a partially ordered set $\mathbf{P}$, denoted ${led}(\mathbf{P})$, as the maximum distance between two linear extensions of $\m...
Analysis of Casino Shelf Shuffling Machines
Casino Shelf Shuffling Machines Combinatorics Probability
2011/9/9
Abstract: Many casinos routinely use mechanical card shuffling machines. We were asked to evaluate a new product, a shelf shuffler. This leads to new probability, new combinatorics, and to some practi...
Sets with High Volume and Low Perimeter
High Volume Low Perimeter Combinatorics Number Theory
2011/9/9
Abstract: In this paper, we consider a certain variation of the "isoperimetric problem" adopted for subsets of nonnegative integers. More specifically, we explore the sequence P(n) as described in OEI...
Hall's Condition for Partial Latin Squares
Hall's Condition Partial Latin Squares Combinatorics
2011/9/5
Abstract: Hall's Condition is a necessary condition for a partial latin square to be completable. Hilton and Johnson showed that for a partial latin square whose filled cells form a rectangle, Hall's ...
The Knotting-Unknotting Game played on Sums of Rational Shadows
The Knotting-Unknotting Game Sums of Rational Shadows Combinatorics Geometric Topology
2011/9/5
Abstract: We consider the recently introduced knotting-unknotting game, in which two players take turns resolving crossings in a knot diagram which initially is missing all its crossing information. O...
An analogue of Ryser's Theorem for partial Sudoku squares
Ryser's Theorem partial Sudoku squares analogue Combinatorics
2011/9/5
Abstract: In 1956 Ryser gave a necessary and sufficient condition for a partial latin rectangle to be completable to a latin square. In 1990 Hilton and Johnson showed that Ryser's condition could be r...
Abstract: These notes give an introduction to the Gabriel-Roiter measure of a finite dimensional algebra. They are based on a series of four lectures at the "Advanced School and Conference on Represen...