A new method to construct task graphs for $\mathcal{H}$-matrix arithmetic is introduced, which uses the information associated with all tasks of standard recursive algorithms, e.g., block index set matrix blocks involved in computation. Task refinement, i.e., replacement by subcomputations, then used proceed hierarchy until containing actual data are reached. This process a natural extension cl...

Ant Colony Optimization (ACO) is a kind of randomized search heuristic that has become very popular for solving problems from combinatorial optimization. Solutions for a given problem are constructed by a random walk on a so-called construction graph. This random walk can be influenced by heuristic information about the problem. In contrast to many successful applications, the theoretical found...

We propose an unfolding semantics for graph transformation systems in the double-pushout (DPO) approach. Mimicking Winskel’s construction for Petri nets, a graph grammar is unfolded into an acyclic branching structure, that is itself a (nondeterministic occurrence) graph grammar describing all the possible computations of the original grammar. The unfolding can be abstracted naturally to a prim...

We study the problem of mapping an unknown environment represented as an unlabelled undirected graph. A robot (or automaton) starting at a single vertex of the graph G has to traverse the graph and return to its starting point building a map of the graph in the process. We are interested in the cost of achieving this task (whenever possible) in terms of the number of edge traversal made by the ...

A complete description and proof of correctness are given for a new polynomial time algorithm for a class of codes based on directed graphs and involving construction well known in system theory. Our construction has already been considered in the literature in relation to other questions. The investigation of codes in this graph-based construction is inspired by analogy with classical cyclic c...

Previously the first author has shown how to construct vertexmagic total labelings (VMTLs) for large families of regular graphs. The construction proceeds by successively adding arbitrary 2-factors to a regular graph of order n which possesses a strong VMTL, to produce a regular graph of the same order but larger size. In this paper, we exploit this construction method. We are able to show that...

Let H be a family of graphs. We say that G is H-universal if, for each H ∈ H, the graph G contains a subgraph isomorphic to H. Let H(k, n) denote the family of graphs on n vertices with maximum degree at most k. For each fixed k and each n sufficiently large, we explicitly construct an H(k, n)-universal graph Γ (k, n) with O(n(log n)) edges. This is optimal up to a small polylogarithmic factor,...

In this paper, we address the scalability issue plaguing graph-based semi-supervised learning via a small number of anchor points which adequately cover the entire point cloud. Critically, these anchor points enable nonparametric regression that predicts the label for each data point as a locally weighted average of the labels on anchor points. Because conventional graph construction is ineffic...

Speciication and rapid prototyping of graph manipulating software by means of PROgrammed Graph REwriting Systems (PROGRES) is a paradigm, which attracts more and more interests in various elds of computer science. Nowadays produced speci-cations for process modelling tools, database query languages, or Conceptual Graph manipulations have a typical size of about 100 printed pages. They suuer sev...

In traditional analysis, the constructions of Chinese V-V compounds are generally categorized, according to the grammatical relation between the component V’s, into three major types: coordination (並列式), modifier-head (偏正式) and verb-complement (述補式). Though the widely accepted categorization criteria seem to be simple and straightforward, linguists could often come to completely different judgm...