Grid computing is a newly developed technology for complex systems with large-scale resource sharing, wide-area communication, and multi-institutional collaboration. Although the developmental tools and infrastructures for the grid have been widely studied, grid reliability analysis and modeling are not easy because of its largeness, complexity and stiffness. This chapter introduces the grid co...

In an orthogeodesic embedding of a graph, each edge is embedded as an axis-parallel polyline that forms a shortest path in the `1 metric. In this paper we consider orthogeodesic plane embeddings of trees on grids. A grid is implicitly defined by a set P ⊂ R of points. Denote by ΓP the arrangement induced by all horizontal and vertical lines that pass through a point from P . When embedding a gr...

Incorporating skills in reinforcement learning methods results in accelerate agents learning performance. The key problem of automatic skill discovery is to find subgoal states and create skills to reach them. Among the proposed algorithms, those based on graph centrality measures have achieved precise results. In this paper we propose a new graph centrality measure for identifying subgoal stat...

Unit square (grid) visibility graphs (USV and USGV, resp.) are described by axisparallel visibility between unit squares placed (on integer grid coordinates) in the plane. We investigate combinatorial properties of these graph classes and the hardness of variants of the recognition problem, i. e., the problem of representing USGV with fixed visibilities within small area and, for USV, the gener...

In this paper, we consider the following graph embedding problem: Given a bipartite graph G = (V1, V2;E), where the maximum degree of vertices in V2 is 4, can G be embedded on a two dimensional grid such that each vertex in V1 is drawn as a line segment along a grid line, each vertex in V2 is drawn as a point at a grid point, and each edge e = (u, v) for some u ∈ V1 and v ∈ V2 is drawn as a lin...

We consider distance matrices of certain graphs and of points chosen in a rectangular grid. Formulae for the inverse and the determinant of the distance matrix of a weighted tree are obtained. Results concerning the inertia and the determinant of the distance matrix of an unweighted unicyclic graph are proved. If D is the distance matrix of a tree, then we obtain certain results for a perturbat...

GRID superscalar is a Grid programming environment that enables one to parallelize the execution of sequential applications in computational Grids. The run-time library automatically builds a task datadependence graph of the application and it can be seen as an implicit workflow system. The current interface supports C/C++ and Perl applications. The run-time library is based on Globus Toolkit 2...

To develop grid scheduling algorithms, a high performance simulator is necessary since grid is an uncontrollable and unrepeatable environment. In this paper, a discrete event simulation library called HyperSim is used as extensible building blocks for grid scheduling simulator. The use of event graph model for the grid simulation are proposed. This model is well supported by HyperSim which yiel...

For given a pair of nodes in a graph, the minimum non-separating path problem looks for a minimum weight path between the two nodes such that the remaining graph after removing the path is still connected. The balanced connected bipartition (BCP2) problem looks for a way to bipartition a graph into two connected subgraphs with their weights as equal as possible. In this paper we present an O(N ...

This paper combines the fundamentals of an electrical grid, such as flow allocation according to Kirchhoff’s laws and the effect of transmission line reactances, with spectral graph theory, and expresses the linearised power flow behaviour in slackbus independent weighted graph matrices to assess the relation between the topological structure and the physical behaviour of a power grid. Based on...