56 research outputs found
About Berge-F\"uredi's conjecture on the chromatic index of hypergraphs
Full text linkWe show that the chromatic index of a hypergraph satisfies
Berge-F\"uredi conjectured bound under certain hypotheses on the antirank
or on the maximum degree . This
provides sharp information in connection with Erd\H{o}s-Faber-Lov\'asz
Conjecture which deals with the coloring of a family of cliques that intersect
pairwise in at most one vertex
The Berge-F\"uredi conjecture on the chromatic index of hypergraphs with large hyperedges
Full text linkThis paper is concerned with two conjectures which are intimately related.
The first is a generalization to hypergraphs of Vizing's Theorem on the
chromatic index of a graph and the second is the well-known conjecture of
Erd\H{o}s, Faber and Lov\'asz which deals with the problem of coloring a family
of cliques intersecting in at most one vertex. We are led to study a special
class of uniform and linear hypergraphs for which a number of properties are
established
Electrically induced tunable cohesion in granular systems
Full text linkExperimental observations of confined granular materials in the presence of
an electric field that induces cohesive forces are reported. The angle of
repose is found to increase with the cohesive force. A theoretical model for
the stability of a granular heap, including both the effect of the sidewalls
and cohesion is proposed. A good agreement between this model and the
experimental results is found. The steady-state flow angle is practically
unaffected by the electric field except for high field strengths and low flow
rates.Comment: accepted for publication in "Journal of Statistical Mechanics: Theory
and Experiment
ON THE PADOVAN SEQUENCE
Full text linkThe aim of this article is to give some properties of the so-called Padovan sequence (Tn) n≥0 defined by Tn+3 = Tn+1 + Tn for all n ∈ N, T1 = T2 = T3 = 1 that is divisibility properties, periods, identities
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