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敲竹杠

Nondeterministic control structures for graph rewriting systems,ct .rected, .ttributed, .ode- and .dge- labeled graphs (diane graphs) are used to model the internal structure of software documents and .grammed .raph .writing .tems are used to specify the operational behavior of document processing tools like syntax-directed editors, static analyzers, or incremen

配偶

A language for generic graph-transformations,ations of these graphs. We therefore first define five transformation-operations on this graph-class. Then we define . as a natural generalization of the concept of BP-completeness, originally defined for the relational database model. Our main result states that the language consisting of the five

upstart

Attributed elementary programmed graph grammars,raph productions, namely the addition, the deletion and the renaming of a node or an edge. Although these elementary graph productions are acting strictly locally and no embedding transformations are needed, in the unrestricted and monotone case, elementary programmed graph grammars have the same ge

洞察力

The complexity of approximating the class Steiner tree problem,ode of each required class. This problem called . is NP-hard and therefore we are dependent on approximation..In this paper, we investigate various restrictions of the problem comparing their complexities with respect to approximability. A main result is that for an input of trees without Steiner no

jocular

On complexity of some chain and antichain partition problems,-element chains (resp. antichains). We show that .., ., is NP-complete even for N-free ordered sets of length at most .. and .. are polynomial for series-paralel orders and .. is polynomial for interval orders. We also consider related problems for graphs.

Invigorate

Tight bounds for the rectangular art gallery problem, are always sufficient to protect all rooms in a rectangular art gallery; furthermore, their positioning can be determined in O(n) time. We show that the optimal positioning of the guards can be determined in linear time. We extend the result by proving that in an arbitrary orthogonal art gallery (n

paltry

Voronoi diagrams of moving points in the plane,efine a Voronoi diagram. As the points move, the Voronoi diagram changes continuously, but at certain critical instants in time, topological . occur that cause a change in the Delaunay diagram. In this paper, we present a method of . the Voronoi diagram over time, while showing that the number of to

FLAGR

Using maximal independent sets to solve problems in parallel,e maximal vertex-induced subgraph satisfying a hereditary graph property π can be found in time .(Δ...(.)(log .).) using a polynomial number of processors, where λ(π) is the maximum of diameters of minimal graphs violating π and ..(.) is the time needed to decide whether a graph with . vertices sati

減少

護(hù)航艦