39 research outputs found
Fault-tolerant hamiltonian connectedness of cycle composition networks
Abstract It is important for a network to tolerate as many faults as possible. With the graph representation of an interconnection network, a k-regular hamiltonian and hamiltonian connected network is super fault-tolerant hamiltonian if it remains hamiltonian after removing up to k À 2 vertices and/or edges and remains hamiltonian connected after removing up to k À 3 vertices and/or edges. Super fault-tolerant hamiltonian networks have an optimal flavor with regard to the fault-tolerant hamiltonicity and fault-tolerant hamiltonian connectivity. For this reason, a cycle composition framework was proposed to construct a (k + 2)-regular super fault-tolerant hamiltonian network based on a collection of n k-regular super fault-tolerant hamiltonian networks containing the same number of vertices for n P 3 and k P 5. This paper is aimed to emphasize that the cycle composition framework can be still applied even when k = 4
The super-connectivity of Johnson graphs
For positive integers and , the uniform subset graph
has all -subsets of as vertices and two -subsets are
joined by an edge if they intersect at exactly elements. The Johnson graph
corresponds to , that is, two vertices of are
adjacent if the intersection of the corresponding -subsets has size . A
super vertex-cut of a connected graph is a set of vertices whose removal
disconnects the graph without isolating a vertex and the super-connectivity is
the size of a minimum super vertex-cut. In this work, we fully determine the
super-connectivity of the family of Johnson graphs for
A multipath analysis of biswapped networks.
Biswapped networks of the form have recently been proposed as interconnection networks to be implemented as optical transpose interconnection systems. We provide a systematic construction of vertex-disjoint paths joining any two distinct vertices in , where is the connectivity of . In doing so, we obtain an upper bound of on the -diameter of , where is the diameter of and the -diameter. Suppose that we have a deterministic multipath source routing algorithm in an interconnection network that finds mutually vertex-disjoint paths in joining any distinct vertices and does this in time polynomial in , and (and independently of the number of vertices of ). Our constructions yield an analogous deterministic multipath source routing algorithm in the interconnection network that finds mutually vertex-disjoint paths joining any distinct vertices in so that these paths all have length bounded as above. Moreover, our algorithm has time complexity polynomial in , and . We also show that if is Hamiltonian then is Hamiltonian, and that if is a Cayley graph then is a Cayley graph
Higher-Order Triangular-Distance Delaunay Graphs: Graph-Theoretical Properties
We consider an extension of the triangular-distance Delaunay graphs
(TD-Delaunay) on a set of points in the plane. In TD-Delaunay, the convex
distance is defined by a fixed-oriented equilateral triangle ,
and there is an edge between two points in if and only if there is an empty
homothet of having the two points on its boundary. We consider
higher-order triangular-distance Delaunay graphs, namely -TD, which contains
an edge between two points if the interior of the homothet of
having the two points on its boundary contains at most points of . We
consider the connectivity, Hamiltonicity and perfect-matching admissibility of
-TD. Finally we consider the problem of blocking the edges of -TD.Comment: 20 page