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On minimal strong blocks

✍ Scribed by Martin Grötschel

Publisher
John Wiley and Sons
Year
1979
Tongue
English
Weight
319 KB
Volume
3
Category
Article
ISSN
0364-9024

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✦ Synopsis

Abstract

It is shown that storng blocks, i.e., digraphs that are strongly connected and have no cutnodes have an ear‐decomposition. This result is used to prove that the number q of arcs of minimal strong blocks is bounded by p ≤ q ≤ 2p – 3 and that minimal strong blocks contain at least two nodes with indegree and outdegree equal to one.

📜 SIMILAR VOLUMES

On strong digraphs with a unique minimal
On strong digraphs with a unique minimally strong subdigraph
✍ Richard A. Brualdi; Rachel Manber 📂 Article 📅 1988 🏛 Elsevier Science 🌐 English ⚖ 659 KB

In this paper we determine the maximum number of &ges that a strong digraph can have if it has a unique minimally stroug subdigraph. We show that this number equais lrils = I)/2 + 1. Furthermore we show that there is, &to an isomorphism, a unique strong &graph which attains this maximum.

Strong Minimal Covers for Recursively En
Strong Minimal Covers for Recursively Enumerable Degrees
✍ S. Barry Cooper 📂 Article 📅 1996 🏛 John Wiley and Sons 🌐 English ⚖ 386 KB

## Abstract We prove that there exists a nonzero recursively enumerable Turing degree possessing a strong minimal cover. Mathematics Subject Classification: 03D30.

On large minimal blocking sets in PG(2,q
On large minimal blocking sets in PG(2,q)
✍ Tamás Szőnyi; Antonello Cossidente; András Gács; Csaba Mengyán; Alessandro Sicil 📂 Article 📅 2004 🏛 John Wiley and Sons 🌐 English ⚖ 172 KB 👁 1 views

## Abstract The size of large minimal blocking sets is bounded by the Bruen–Thas upper bound. The bound is sharp when __q__ is a square. Here the bound is improved if __q__ is a non‐square. On the other hand, we present some constructions of reasonably large minimal blocking sets in planes of non‐p