Results 1 to 10 of about 45,393 (304)

Geometries on partially ordered sets

Journal of Combinatorial Theory, Series B, 1980
AbstractGeometries on finite partially ordered sets extend the concept of matroids on finite sets to partially ordered sets. Geometries are defined in terms of closure operators on partially ordered sets. The lattice of closed sets is semimodular, and every finite semimodular lattice is isomorphic to the lattice of closed sets of some geometry.
Faigle, Ulrich
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Correlation in partially ordered sets

Discrete Applied Mathematics, 1992
Basic results concerning correlation within ordered sets that focus on distributive lattices, systems of subsets ordered by proper inclusion and the family of linear extensions of an arbitrary finite ordered set are reviewed in this paper. Let us quote some interesting results: the Ahlswede-Daykin theorem, the FKG theorem, the universal correlation ...
Fishburn, Peter C.
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On Sums Over Partially Ordered Sets [PDF]

The Electronic Journal of Combinatorics, 1999
We establish a general theorem for reducing sums of type $\sum_{y\ge x} g(y)$ where $g$ is a mapping from a partially ordered set into an abelian group. Conclusions concern the Möbius function, the principle of inclusion-exclusion, the Tutte polynomial and Crapo's beta invariant.
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Existence and uniqueness of positive solutions to higher-order nonlinear fractional differential equation with integral boundary conditions

Electronic Journal of Differential Equations, 2012
In this article, we consider the nonlinear fractional order three-point boundary-value problem $$displaylines{ D_{0+}^{alpha} u(t) + f(t,u(t))=0, quad 0 < t < 1,cr u(0) = u'(0) = dots = u^{(n-2)}(0)=0, quad u^{(n-2)}(1) = int_0^eta u(s)ds, }$$
Chenxing Zhou
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Searching in random partially ordered sets

Theoretical Computer Science, 2004
zbMATH Open Web Interface contents unavailable due to conflicting licenses.
Renato Carmo, Jair Donadelli, Yoshiharu Kohayakawa, Eduardo Sany Laber   +3 more
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Order-sensitive domination in partially ordered sets

CoRR, 2020
For a (finite) partially ordered set (poset) $P$, we call a dominating set $D$ in the comparability graph of $P$, an order-sensitive dominating set in $P$ if either $x\in D$ or else ...
Yusuf Civan, Zakir Deniz, Mehmet Akif Yetim   +2 more
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Positive Solutions of Nonlinear Fractional Differential Equations with Integral Boundary Value Conditions

Abstract and Applied Analysis, 2012
We investigate the existence and uniqueness of positive solutions of the following nonlinear fractional differential equation with integral boundary value conditions, , , where , and is the Caputo fractional derivative and is a continuous function ...
J. Caballero, I. Cabrera, K. Sadarangani
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Set-theoretic Analysis of Nominative Data [PDF]

Computer Science Journal of Moldova, 2015
In the paper we investigate the notion of nominative data that can be considered as a general mathematical model of data used in computing systems. The main attention is paid to flat nominative data called nominative sets.
Volodymyr G. Skobelev, Ievgen Ivanov, Mykola Nikitchenko   +2 more
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A remark on the extension of the concept of incidence algebras to nonlocally finite partially ordered sets

International Journal of Mathematics and Mathematical Sciences, 2004
An incidence algebra of a nonlocally finite partially ordered set Q is a very rare concept, perhaps nonexistent. In this note, we will attempt to construct such an algebra.
Boniface I. Eke
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Unique Solution of a Coupled Fractional Differential System Involving Integral Boundary Conditions from Economic Model

Abstract and Applied Analysis, 2013
We study the existence and uniqueness of the positive solution for the fractional differential system involving the Riemann-Stieltjes integral boundary conditions , , , , , and , where , , and and are the standard Riemann-Liouville derivatives, and ...
Rui Li, Haoqian Zhang, Hao Tao
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