In this paper we propose a greedy heuristic to solve the non preemptive multiprocessor static scheduling problem with precedence and strict periodicity constraints. The system of periodic tasks is described by a graph where dependent tasks are connected by precedence constraints. First, each task is repeated within the LCM of all periods of tasks (hyper-period) allowing to unroll the graph over...

Applications of graph and hypergraph decomposition techniques to SAT solving have been studied under various conditions. Theoretical research focused on the direction given by tree decompositions, while practical approaches either integrated tree decomposition guidance into existing SAT solver, or studied splitting techniques using hypergraph cuts. In this article we present a uniform and gener...

A social networking service is an online service, platform, or site that focuses on facilitating the building of social networks or social relations among people who, for example, share interests, activities, backgrounds, or reallife connections. A social network service consists of a representation of each user, his/her social links, and a variety of additional services. Most social network se...

A (hereditarily finite) set/hyperset S can be completely depicted by a (finite pointed) graph GS—dubbed its membership graph— in which every node represents an element of the transitive closure of {S} and every arc represents a membership relation holding between its source and its target. In a membership graph different nodes must have different sets of successors and, more generally, if the g...

Abstmcr-The n-star graph, denoted by S,, is one of the graph networks that have been recently proposed as attractive alternatives to the n-cube topology for interconnecting processors in parallel computers. In this paper, we present a parallel algorithm for the computation of the Fourier transform on the star graph. The algorithm requires O(n*)multiply-add steps for an input sequence of n! elem...

A directed star forest is a forest all of whose components are stars with arcs emanating from the center to the leaves. The acircuitic directed star arboricity of an oriented graph G (that is a digraph with no opposite arcs) is the minimum number of edge-disjoint directed star forests whose union covers all edges of G and such that the union of any two such forests is acircuitic. We show that e...

Let G be a connected graph with least eigenvalue −2, of multiplicity k. A star complement for −2 in G is an induced subgraph H = G − X such that |X | = k and −2 is not an eigenvalue of H . In the case that G is a generalized line graph, a characterization of such subgraphs is used to decribe the eigenspace of −2. In some instances, G itself can be characterized by a star complement. If G is not...

A significant body of literature has explored various research directions in hyper-heuristics (which can be thought as heuristics to choose heuristics). In this paper we define a graph based hyper-heuristic (GHH) framework and compare the performance of a number of local search based searching algorithms as the high level heuristics. They are used to search upon permutations of low level graph ...

A double-star is a tree with exactly two vertices of degree greater than 1. If T is a double-star where the two vertices of degree greater than one have degrees k1+1 and k2+1, then T is denoted by Sk1,k2 . In this note, we show that every double-star with n edges decomposes every 2n-regular graph. We also show that the double-star Sk,k−1 decomposes every 2k-regular graph that contains a perfect...