## Abstract A partially ordered set __P__ is called a __kβsphere order__ if one can assign to each element a β __P__ a ball __B__~__a__~ in __R^k^__ so that __a__ < __b__ iff __B__~__a__~ β __B__~__b__~. To a graph __G__ = (__V,E__) associate a poset __P__(__G__) whose elements are the vertices and
Note on hypergraphs and sphere orders
β Scribed by Alexander Schrijver
- Publisher
- John Wiley and Sons
- Year
- 1993
- Tongue
- English
- Weight
- 163 KB
- Volume
- 17
- Category
- Article
- ISSN
- 0364-9024
No coin nor oath required. For personal study only.
β¦ Synopsis
Abstract
We show that each partial order β€ of height 2 can be represented by spheres in Euclidean space, where inclusion represents β€. If each element has at most k elements under it, we can do this in 2__k__ β 1βdimensional space. This extends a result (and a method) of Scheinerman for the case k = 2. Β© 1993 John Wiley & Sons, Inc.
π SIMILAR VOLUMES
In this note, we study the nonreconstructibility property through examples given by Stockmeyer (for tournaments) and Kocay (for 3-hypergraphs). Relating these examples we show how to obtain non (&1)-reconstructible ternary relations from particular non (&1)-reconstructible binary ones.
We investigate vertex orders that can be used to obtain maximum stable sets by a simple greedy algorithm in polynomial time in some classes of graphs. We characterize a class of graphs for which the stability number can be obtained by a simple greedy algorithm. This class properly contains previousl
A method for refining high order numerical integration schemes is described. Particular focus is on integration schemes over the unit sphere with octahedral symmetry. The method is powerful enough that new integration schemes can be found from rough intuitive guesses. New schemes up to order 59 are