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The notion of noncrossing partitions of a partially ordered set (poset) is introduced here. When the poset in question is $[n]=\{1,2,\dots, n\}$ with the complete order of natural numbers, conventional noncrossing partitions arise. The…

Combinatorics · Mathematics 2024-09-09 Ricky X. F. Chen

A random graph order is a partial order obtained from a random graph on $[n]$ by taking the transitive closure of the adjacency relation. The dimension of the random graph orders from random bipartite graphs $B(n,n,p)$ and from $G(n,p)$…

Combinatorics · Mathematics 2026-01-27 Pu Gao , Arnav Kumar

In this paper we are using the poset representation to describe the complex answers given by IR systems after a clustering and ranking processes. The answers considered may be given by cartographical representations or by thematic sub-lists…

Information Retrieval · Computer Science 2009-06-18 Christine Michel

We study subclasses of grid intersection graphs from the perspective of order dimension. We show that partial orders of height two whose comparability graph is a grid intersection graph have order dimension at most four. Starting from this…

Combinatorics · Mathematics 2015-12-09 Steven Chaplick , Stefan Felsner , Udo Hoffmann , Veit Wiechert

Given a finite set satisfying condition $\mathcal{A}$, the subset selection problem asks, how large of a subset satisfying condition $\mathcal{B}$ can we find? We make progress on three instances of subset selection problems in planar point…

Combinatorics · Mathematics 2024-12-20 József Balogh , Felix Christian Clemen , Adrian Dumitrescu , Dingyuan Liu

We consider 'supersaturation' problems in partially ordered sets (posets) of the following form. Given a finite poset $P$ and an integer $m$ greater than the cardinality of the largest antichain in $P$, what is the minimum number of…

Combinatorics · Mathematics 2017-08-29 Jonathan A. Noel , Alex Scott , Benny Sudakov

We study three different poset structures on the set of all compositions. In the first case, the covering relation consists of inserting a part of size one to the left or to the right, or increasing the size of some part by one. The…

Combinatorics · Mathematics 2007-05-23 Jan Snellman

We prove that a poset with no induced subposet $S_k$ (for fixed $k\geq 3$) must have dimension that is sublinear in terms of the number of elements.

Combinatorics · Mathematics 2013-11-27 Csaba Biro , Peter Hamburger , Attila Por

The general $d$-position number ${\rm gp}_d(G)$ of a graph $G$ is the cardinality of a largest set $S$ for which no three distinct vertices from $S$ lie on a common geodesic of length at most $d$. This new graph parameter generalizes the…

Combinatorics · Mathematics 2020-05-19 Sandi Klavzar , Douglas F. Rall , Ismael G. Yero

Partially ordered sets labeled with k labels (k-posets) and their homomorphisms are examined. We give a representation of directed graphs by k-posets; this provides a new proof of the universality of the homomorphism order of k-posets. This…

Combinatorics · Mathematics 2016-11-22 Leonard Kwuida , Erkko Lehtonen

Dorais asked for the maximum guaranteed size of a dimension $d$ subposet of an $n$-element poset. A lower bound of order $\sqrt{n}$ was found by Goodwillie. We provide a sublinear upper bound for each $d$. For $d=2$, our bound is…

Combinatorics · Mathematics 2014-04-02 Benjamin Reiniger , Elyse Yeager

We generalize the measurement using an expanded concept of cover, in order to provide a new approach to size of set other than cardinality. The generalized measurement has application backgrounds such as a generalized problem in dimension…

General Mathematics · Mathematics 2012-11-13 Hua-Rong Peng , Da-Hai Li , Qiong-Hua Wang

Comparability graphs are graphs which have transitive orientations. The dimension of a poset is the least number of linear orders whose intersection gives this poset. The dimension ${\rm dim}(X)$ of a comparability graph $X$ is the…

Discrete Mathematics · Computer Science 2015-06-17 Pavel Klavík , Peter Zeman

Let $\mathfrak{P}_r$ be a representation system of the non-isomorphic finite posets, and let ${\cal H}(P,Q)$ be the set of order homomorphisms from $P$ to $Q$. For finite posets $R$ and $S$, we write $R \sqsubseteq_G S$ iff, for every $P…

Combinatorics · Mathematics 2019-08-20 Frank a Campo

Previously, Erd\H{o}s, Kierstead and Trotter investigated the dimension of random height~$2$ partially ordered sets. Their research was motivated primarily by two goals: (1)~analyzing the relative tightness of the F\"{u}redi-Kahn upper…

Combinatorics · Mathematics 2020-03-19 Csaba Biró , Peter Hamburger , H. A. Kierstead , Attila Pór , William T. Trotter , Ruidong Wang

We prove that the dimension of every poset whose comparability graph has maximum degree $\Delta$ is at most $\Delta\log^{1+o(1)} \Delta$. This result improves on a 30-year old bound of F\"uredi and Kahn, and is within a $\log^{o(1)}\Delta$…

Combinatorics · Mathematics 2020-02-17 Alex Scott , David R. Wood

We develop dimension theory for a large class of structures called espaliers, consisting of a set $L$ equipped with a partial order $\leq$, an orthogonality relation $\perp$, and an equivalence relation $\sim$, subject to certain axioms.…

General Mathematics · Mathematics 2007-05-23 K. R. Goodearl , F. Wehrung

Rabinovitch showed in 1978 that the interval orders having a representation consisting of only closed unit intervals have order dimension at most 3. This article shows that the same dimension bound applies to two other classes of posets:…

Combinatorics · Mathematics 2022-01-05 Mitchel T. Keller , Ann N. Trenk , Stephen J. Young

The poset of copies of a relational structure ${\mathbb X}$ is the partial order ${\mathbb P} ({\mathbb X} ) := \langle \{ Y \subset X: {\mathbb Y} \cong {\mathbb X}\}, \subset \rangle$ and each similarity of such posets (e.g. isomorphism,…

Logic · Mathematics 2023-10-17 Miloš S. Kurilić , Stevo Todorčević

We study covering numbers and local covering numbers with respect to difference graphs and complete bipartite graphs. In particular we show that in every cover of a Young diagram with $\binom{2k}{k}$ steps with generalized rectangles there…

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