We describe an implementation of Italiano's partially dynamic data structure for maintaining transitive closure information in a directed graph and report on experimental results with random directed graphs and random sequences of operations. The operations supported are edge insertions or edge deletions, and queries. For the case of edge deletions the directed graph is assumed to be acyclic.

In this paper we describe an operation on directed graphs which produces a graph with fewer vertices, such that the C-algebra of the new graph is Morita equivalent to that of the original graph. We unify and generalize several related constructions, notably delays and desingularizations of directed graphs.

In this paper, we deal with editing tabular forms for program specifications based on a particular graph grammar HNGG [2]. First, we formalize syntax-directed editing methods by extending of the notion of the Cornell Program Synthesizer [8] to attribute NCE graph grammars (cf. [1]). Next, we discuss the algorithms of the editing methods. keyword Graph Grammars, Visual Programming, Software Deve...

In the strongly connected spanning subgraph (SCSS) problem, the goal is to find a minimum weight spanning subgraph of a strongly connected directed graph that maintains the strong connectivity. In this paper, we consider the SCSS problem for two families of geometric directed graphs; t-spanners and symmetric disk graphs. Given a constant t ≥ 1, a directed graph G is a t-spanner of a set of poin...

The scheduling and mapping of task graph to processors is considered to be the most crucial NP-complete in parallel and distributed computing systems. In this paper, the theoretical graph application using matching is presented to assign a number of tasks onto two processors. This paper addresses a directed-weighted cyclic graph. The effort is to reduce the graph onto directed acyclic graph. A ...

Mechanical, electrical, and plumbing (MEP) systems are crucial to a building, which directly affect the building safety, energy saving, operational efficiency. Building information models (BIMs) help engineers view connection structure of MEP elements, reducing time for reading drawings training costs. However, existing bring tremendous challenge monitoring due issues with complicated spatial s...