This paper formulates a necessary and sufficient condition for a generic graph matching problem to be equivalent to the maximum vertex and edge weight clique problem in a derived association graph. The consequences of this results are threefold: first, the condition is general enough to cover a broad range of practical graph matching problems; second, a proof to establish equivalence between gr...

The edit distance between two ordered trees with vertex labels is the minimum cost of transforming one tree into the other by a sequence of elementary operations consisting of deleting and relabeling existing nodes, as well as inserting new nodes. In this paper, we present a worstcase O(n)-time algorithm for this problem, improving the previous best O(n log n)time algorithm [6]. Our result requ...

This paper investigates whether meaningful shape categories can be identified in an unsupervised way by clustering shocktrees. We commence by computing weighted and unweighted edit distances between shock-trees extracted from the HamiltonJacobi skeleton of 2D binary shapes. Next we use an EMlike algorithm to locate pairwise clusters in the pattern of edit-distances. We show that when the tree e...

Information distributed through the Web keeps growing faster day by day, and for this reason, several techniques for extracting Web data have been suggested during last years. Often, extraction tasks are performed through so called wrappers, procedures extracting information from Web pages, e.g. implementing logic-based techniques. Many fields of application today require a strong degree of rob...

SRI’s LAW (Link Analysis Workbench) is a system that helps intelligence analysts detect occurrences of situations of interest by finding pattern instances in vast amounts of data using graph edit distance matching techniques. However to be completely successful it has to convey the results of the such findings to the users in a way that they can quickly grasp, not only to make use of it or to p...

In this article, we study the behaviour of dynamic programming methods for the tree edit distance problem, such as [4] and [2]. We show that those two algorithms may be described in a more general framework of cover strategies. This analysis allows us to define a new tree edit distance algorithm, that is optimal for cover strategies.

Methods for evaluating dependency parsing using attachment scores are highly sensitive to representational variation between dependency treebanks, making cross-experimental evaluation opaque. This paper develops a robust procedure for cross-experimental evaluation, based on deterministic unificationbased operations for harmonizing different representations and a refined notion of tree edit dist...

The focus of my research is extremal graph theory and random combinatorial structures. I have also worked in a variety of other areas, including intersecting hypergraphs, the theory of positional games and Ramsey theory. I use a number of tools in my research, notably probabilistic methods and, most prominently, Szemerédi’s regularity lemma. I have used these and other techniques to address que...

We study the behavior of dynamic programming methods for the tree edit distance problem, such as [5,13]. We show that those two algorithms may be described as decomposition strategies. We introduce the general framework of cover strategies, and we provide an exact characterization of the complexity of cover strategies. This analysis allows us to define a new tree edit distance algorithm, that i...

ÐThis paper describes a novel framework for comparing and matching corrupted relational graphs. The paper develops the idea of edit-distance originally introduced for graph-matching by Sanfeliu and Fu [1]. We show how the Levenshtein distance can be used to model the probability distribution for structural errors in the graph-matching problem. This probability distribution is used to locate mat...