For a fixed integer, the k-Colouring problem is to decide if vertices of graph can be coloured with at most k colours for an integer k, such that no two adjacent are alike. A G H-free does not contain H as induced subgraph. It known all k≥3, NP-complete graphs contains claw or cycle. The case where cycle follows from result even arbitrarily large girth. We examine what extent situation may chan...

A particular class of low-density parity-check codes referred to as cylinder-type BC-LDPC codes is proposed by Gholami and Eesmaeili. In this paper We represent a double cylinder-type parity-check matrix H by a graph called the block-structure graph of H and denoted by BSG(H). Using the properties of BSG(H) we propose some mother matrices with column-weight two such that the rate of correspondi...

An exact meet in a lattice is a special type of infimum characterized by, inter alia, distributing over finite joins. In frames, the requirement that a meet is preserved by all frame homomorphisms makes for a slightly stronger property. In this paper these concepts are studied systematically, starting with general lattices and proceeding through general frames to spatial ones, and finally to an...

" By giving a name to something, you acquire power over it " (one of " Scott's Laws " proposed by the late Professor Bernard Scott, Sussex University)

A nonempty vertex set X ⊆ V (G) of a hamiltonian graph G is called an H-force set of G if every X-cycle of G (i.e. a cycle of G containing all vertices of X) is hamiltonian. The H-force number h(G) of a graph G is defined to be the smallest cardinality of an H-force set of G. In the paper the study of this parameter is introduced and its value or a lower bound for outerplanar graphs, planar gra...

the cold climate is a favorable parameter for the development of tension cracks and decrease of rock brittleness. therefore, this paper attempts to investigate the hamekasi porous limestone in order to predict the brittleness indices during freeze-thaw cycles. the freeze–thaw test was executed for one cycle including 16 h of freezing, and 8 h of thawing. the geo mechanical properties and brittl...

In order to elucidate further the mechanism of reversible cell cycle arrest induced by treatment of Raji cells with 1.5% dimethyl sulfoxide (DMSO), we have performed a detailed analysis of the kinetics of arrest and of reentry into the cell cycle after removal of DMSO and have correlated cell cycle progression with expression of proliferating cell nuclear antigen (PCNA). No significant effect o...